[gcv v3 01/35] x86: Use this_cpu_inc/dec for debug registers

[gcv v3 01/35] x86: Use this_cpu_inc/dec for debug registers

[Christoph Lameter]

I think this patch already exists in one form or another in some x86 tree.

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/x86/include/asm/debugreg.h
===================================================================
--- linux.orig/arch/x86/include/asm/debugreg.h	2013-08-06 13:52:23.740092873 -0500
+++ linux/arch/x86/include/asm/debugreg.h	2013-08-06 13:52:23.740092873 -0500
@@ -97,11 +97,11 @@ extern void hw_breakpoint_restore(void);
 DECLARE_PER_CPU(int, debug_stack_usage);
 static inline void debug_stack_usage_inc(void)
 {
-	__get_cpu_var(debug_stack_usage)++;
+	__this_cpu_inc(debug_stack_usage);
 }
 static inline void debug_stack_usage_dec(void)
 {
-	__get_cpu_var(debug_stack_usage)--;
+	__this_cpu_dec(debug_stack_usage);
 }
 int is_debug_stack(unsigned long addr);
 void debug_stack_set_zero(void);
Index: linux/arch/x86/kernel/cpu/common.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/common.c	2013-07-19 09:06:36.850047837 -0500
+++ linux/arch/x86/kernel/cpu/common.c	2013-08-06 13:54:36.426384889 -0500
@@ -1144,9 +1144,9 @@ DEFINE_PER_CPU(int, debug_stack_usage);
 
 int is_debug_stack(unsigned long addr)
 {
-	return __get_cpu_var(debug_stack_usage) ||
-		(addr <= __get_cpu_var(debug_stack_addr) &&
-		 addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));
+	return __this_cpu_read(debug_stack_usage) ||
+		(addr <= __this_cpu_read(debug_stack_addr) &&
+		 addr > (__this_cpu_read(debug_stack_addr) - DEBUG_STKSZ));
 }
 
 DEFINE_PER_CPU(u32, debug_idt_ctr);

[gcv v3 02/35] percpu: Make __verify_pcu_ptr handle per cpu pointers to arrays

[Christoph Lameter]

__verify_pcpu_ptr() will cause a compilation failure if the type of the
pointer is a pointer to a fixed array of objects. Adding zero to the
pointer converts the type of pointer to that pointing to a single
object of the array.

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/linux/percpu-defs.h
===================================================================
--- linux.orig/include/linux/percpu-defs.h	2013-08-22 13:39:04.000000000 -0500
+++ linux/include/linux/percpu-defs.h	2013-08-22 13:41:15.333140537 -0500
@@ -22,9 +22,12 @@
  * Macro which verifies @ptr is a percpu pointer without evaluating
  * @ptr.  This is to be used in percpu accessors to verify that the
  * input parameter is a percpu pointer.
+ *
+ * + 0 is required in order to convert the pointer type from a
+ * potential array type to a pointer to a single item of the array.
  */
 #define __verify_pcpu_ptr(ptr)	do {					\
-	const void __percpu *__vpp_verify = (typeof(ptr))NULL;		\
+	const void __percpu *__vpp_verify = (typeof((ptr) + 0))NULL;	\
 	(void)__vpp_verify;						\
 } while (0)
 

[gcv v3 34/35] metag: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/metag/kernel/perf/perf_event.c
===================================================================
--- linux.orig/arch/metag/kernel/perf/perf_event.c	2013-08-26 13:30:45.220186762 -0500
+++ linux/arch/metag/kernel/perf/perf_event.c	2013-08-26 13:30:45.216186804 -0500
@@ -258,7 +258,7 @@ int metag_pmu_event_set_period(struct pe
 
 static void metag_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -306,7 +306,7 @@ static void metag_pmu_stop(struct perf_e
 
 static int metag_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = 0, ret = 0;
 
@@ -348,7 +348,7 @@ out:
 
 static void metag_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -607,7 +607,7 @@ static int _hw_perf_event_init(struct pe
 
 static void metag_pmu_enable_counter(struct hw_perf_event *event, int idx)
 {
-	struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
 	unsigned int config = event->config;
 	unsigned int tmp = config & 0xf0;
 	unsigned long flags;
@@ -680,7 +680,7 @@ unlock:
 
 static void metag_pmu_disable_counter(struct hw_perf_event *event, int idx)
 {
-	struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
 	unsigned int tmp = 0;
 	unsigned long flags;
 
@@ -728,7 +728,7 @@ out:
 
 static void metag_pmu_write_counter(int idx, u32 val)
 {
-	struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
 	u32 tmp = 0;
 	unsigned long flags;
 
@@ -761,7 +761,7 @@ static int metag_pmu_event_map(int idx)
 static irqreturn_t metag_pmu_counter_overflow(int irq, void *dev)
 {
 	int idx = (int)dev;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event = cpuhw->events[idx];
 	struct hw_perf_event *hwc = &event->hw;
 	struct pt_regs *regs = get_irq_regs();

[gcv v3 34/35] metag: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/metag/kernel/perf/perf_event.c
===================================================================
--- linux.orig/arch/metag/kernel/perf/perf_event.c	2013-08-26 13:30:45.220186762 -0500
+++ linux/arch/metag/kernel/perf/perf_event.c	2013-08-26 13:30:45.216186804 -0500
@@ -258,7 +258,7 @@ int metag_pmu_event_set_period(struct pe
 
 static void metag_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -306,7 +306,7 @@ static void metag_pmu_stop(struct perf_e
 
 static int metag_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = 0, ret = 0;
 
@@ -348,7 +348,7 @@ out:
 
 static void metag_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -607,7 +607,7 @@ static int _hw_perf_event_init(struct pe
 
 static void metag_pmu_enable_counter(struct hw_perf_event *event, int idx)
 {
-	struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
 	unsigned int config = event->config;
 	unsigned int tmp = config & 0xf0;
 	unsigned long flags;
@@ -680,7 +680,7 @@ unlock:
 
 static void metag_pmu_disable_counter(struct hw_perf_event *event, int idx)
 {
-	struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
 	unsigned int tmp = 0;
 	unsigned long flags;
 
@@ -728,7 +728,7 @@ out:
 
 static void metag_pmu_write_counter(int idx, u32 val)
 {
-	struct cpu_hw_events *events = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *events = this_cpu_ptr(&cpu_hw_events);
 	u32 tmp = 0;
 	unsigned long flags;
 
@@ -761,7 +761,7 @@ static int metag_pmu_event_map(int idx)
 static irqreturn_t metag_pmu_counter_overflow(int irq, void *dev)
 {
 	int idx = (int)dev;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event = cpuhw->events[idx];
 	struct hw_perf_event *hwc = &event->hw;
 	struct pt_regs *regs = get_irq_regs();

[gcv v3 20/35] zcache/zsmalloc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/staging/zcache/ramster/ramster.c
===================================================================
--- linux.orig/drivers/staging/zcache/ramster/ramster.c	2013-08-22 14:14:40.400841754 -0500
+++ linux/drivers/staging/zcache/ramster/ramster.c	2013-08-22 14:15:51.000000000 -0500
@@ -82,7 +82,7 @@ static struct flushlist_node *ramster_fl
 	struct flushlist_node *flnode = NULL;
 	struct ramster_preload *kp;
 
-	kp = &__get_cpu_var(ramster_preloads);
+	kp = this_cpu_ptr(&ramster_preloads);
 	flnode = kp->flnode;
 	BUG_ON(flnode == NULL);
 	kp->flnode = NULL;
@@ -109,7 +109,7 @@ int ramster_do_preload_flnode(struct tme
 	BUG_ON(!irqs_disabled());
 	if (unlikely(ramster_flnode_cache == NULL))
 		BUG();
-	kp = &__get_cpu_var(ramster_preloads);
+	kp = this_cpu_ptr(&ramster_preloads);
 	flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC);
 	if (unlikely(flnode == NULL) && kp->flnode == NULL)
 		BUG();  /* FIXME handle more gracefully, but how??? */
@@ -478,8 +478,8 @@ int ramster_remotify_pageframe(bool eph)
 	struct tmem_handle th[2];
 	unsigned int zsize[2];
 
-	tmpmem[0] = __get_cpu_var(ramster_remoteputmem1);
-	tmpmem[1] = __get_cpu_var(ramster_remoteputmem2);
+	tmpmem[0] = __this_cpu_read(ramster_remoteputmem1);
+	tmpmem[1] = __this_cpu_read(ramster_remoteputmem2);
 	local_bh_disable();
 	zbuds = zbud_make_zombie_lru(&th[0], &tmpmem[0], &zsize[0], eph);
 	/* now OK to release lock set in caller */
Index: linux/drivers/staging/zcache/zcache-main.c
===================================================================
--- linux.orig/drivers/staging/zcache/zcache-main.c	2013-08-22 14:14:40.400841754 -0500
+++ linux/drivers/staging/zcache/zcache-main.c	2013-08-22 14:15:51.000000000 -0500
@@ -250,7 +250,7 @@ static struct tmem_objnode *zcache_objno
 	struct zcache_preload *kp;
 	int i;
 
-	kp = &__get_cpu_var(zcache_preloads);
+	kp = this_cpu_ptr(&zcache_preloads);
 	for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
 		objnode = kp->objnodes[i];
 		if (objnode != NULL) {
@@ -275,7 +275,7 @@ static struct tmem_obj *zcache_obj_alloc
 	struct tmem_obj *obj = NULL;
 	struct zcache_preload *kp;
 
-	kp = &__get_cpu_var(zcache_preloads);
+	kp = this_cpu_ptr(&zcache_preloads);
 	obj = kp->obj;
 	BUG_ON(obj == NULL);
 	kp->obj = NULL;
@@ -531,7 +531,7 @@ void *zcache_pampd_create(char *data, un
 	/* pre-allocate per-cpu metadata */
 	BUG_ON(zcache_objnode_cache == NULL);
 	BUG_ON(zcache_obj_cache == NULL);
-	kp = &__get_cpu_var(zcache_preloads);
+	kp = this_cpu_ptr(&zcache_preloads);
 	for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
 		objnode = kp->objnodes[i];
 		if (objnode == NULL) {
@@ -761,7 +761,7 @@ static DEFINE_PER_CPU(unsigned char *, z
 static void zcache_compress(struct page *from, void **out_va, unsigned *out_len)
 {
 	int ret;
-	unsigned char *dmem = __get_cpu_var(zcache_dstmem);
+	unsigned char *dmem = __this_cpu_read(zcache_dstmem);
 	char *from_va;
 
 	BUG_ON(!irqs_disabled());
Index: linux/drivers/staging/zsmalloc/zsmalloc-main.c
===================================================================
--- linux.orig/drivers/staging/zsmalloc/zsmalloc-main.c	2013-08-22 14:14:29.000000000 -0500
+++ linux/drivers/staging/zsmalloc/zsmalloc-main.c	2013-08-22 14:15:51.000000000 -0500
@@ -1028,7 +1028,7 @@ void zs_unmap_object(struct zs_pool *poo
 	class = &pool->size_class[class_idx];
 	off = obj_idx_to_offset(page, obj_idx, class->size);
 
-	area = &__get_cpu_var(zs_map_area);
+	area = this_cpu_ptr(&zs_map_area);
 	if (off + class->size <= PAGE_SIZE)
 		kunmap_atomic(area->vm_addr);
 	else {

[gcv v3 20/35] zcache/zsmalloc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/staging/zcache/ramster/ramster.c
===================================================================
--- linux.orig/drivers/staging/zcache/ramster/ramster.c	2013-08-22 14:14:40.400841754 -0500
+++ linux/drivers/staging/zcache/ramster/ramster.c	2013-08-22 14:15:51.000000000 -0500
@@ -82,7 +82,7 @@ static struct flushlist_node *ramster_fl
 	struct flushlist_node *flnode = NULL;
 	struct ramster_preload *kp;
 
-	kp = &__get_cpu_var(ramster_preloads);
+	kp = this_cpu_ptr(&ramster_preloads);
 	flnode = kp->flnode;
 	BUG_ON(flnode == NULL);
 	kp->flnode = NULL;
@@ -109,7 +109,7 @@ int ramster_do_preload_flnode(struct tme
 	BUG_ON(!irqs_disabled());
 	if (unlikely(ramster_flnode_cache == NULL))
 		BUG();
-	kp = &__get_cpu_var(ramster_preloads);
+	kp = this_cpu_ptr(&ramster_preloads);
 	flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC);
 	if (unlikely(flnode == NULL) && kp->flnode == NULL)
 		BUG();  /* FIXME handle more gracefully, but how??? */
@@ -478,8 +478,8 @@ int ramster_remotify_pageframe(bool eph)
 	struct tmem_handle th[2];
 	unsigned int zsize[2];
 
-	tmpmem[0] = __get_cpu_var(ramster_remoteputmem1);
-	tmpmem[1] = __get_cpu_var(ramster_remoteputmem2);
+	tmpmem[0] = __this_cpu_read(ramster_remoteputmem1);
+	tmpmem[1] = __this_cpu_read(ramster_remoteputmem2);
 	local_bh_disable();
 	zbuds = zbud_make_zombie_lru(&th[0], &tmpmem[0], &zsize[0], eph);
 	/* now OK to release lock set in caller */
Index: linux/drivers/staging/zcache/zcache-main.c
===================================================================
--- linux.orig/drivers/staging/zcache/zcache-main.c	2013-08-22 14:14:40.400841754 -0500
+++ linux/drivers/staging/zcache/zcache-main.c	2013-08-22 14:15:51.000000000 -0500
@@ -250,7 +250,7 @@ static struct tmem_objnode *zcache_objno
 	struct zcache_preload *kp;
 	int i;
 
-	kp = &__get_cpu_var(zcache_preloads);
+	kp = this_cpu_ptr(&zcache_preloads);
 	for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
 		objnode = kp->objnodes[i];
 		if (objnode != NULL) {
@@ -275,7 +275,7 @@ static struct tmem_obj *zcache_obj_alloc
 	struct tmem_obj *obj = NULL;
 	struct zcache_preload *kp;
 
-	kp = &__get_cpu_var(zcache_preloads);
+	kp = this_cpu_ptr(&zcache_preloads);
 	obj = kp->obj;
 	BUG_ON(obj == NULL);
 	kp->obj = NULL;
@@ -531,7 +531,7 @@ void *zcache_pampd_create(char *data, un
 	/* pre-allocate per-cpu metadata */
 	BUG_ON(zcache_objnode_cache == NULL);
 	BUG_ON(zcache_obj_cache == NULL);
-	kp = &__get_cpu_var(zcache_preloads);
+	kp = this_cpu_ptr(&zcache_preloads);
 	for (i = 0; i < ARRAY_SIZE(kp->objnodes); i++) {
 		objnode = kp->objnodes[i];
 		if (objnode == NULL) {
@@ -761,7 +761,7 @@ static DEFINE_PER_CPU(unsigned char *, z
 static void zcache_compress(struct page *from, void **out_va, unsigned *out_len)
 {
 	int ret;
-	unsigned char *dmem = __get_cpu_var(zcache_dstmem);
+	unsigned char *dmem = __this_cpu_read(zcache_dstmem);
 	char *from_va;
 
 	BUG_ON(!irqs_disabled());
Index: linux/drivers/staging/zsmalloc/zsmalloc-main.c
===================================================================
--- linux.orig/drivers/staging/zsmalloc/zsmalloc-main.c	2013-08-22 14:14:29.000000000 -0500
+++ linux/drivers/staging/zsmalloc/zsmalloc-main.c	2013-08-22 14:15:51.000000000 -0500
@@ -1028,7 +1028,7 @@ void zs_unmap_object(struct zs_pool *poo
 	class = &pool->size_class[class_idx];
 	off = obj_idx_to_offset(page, obj_idx, class->size);
 
-	area = &__get_cpu_var(zs_map_area);
+	area = this_cpu_ptr(&zs_map_area);
 	if (off + class->size <= PAGE_SIZE)
 		kunmap_atomic(area->vm_addr);
 	else {

[gcv v3 23/35] s390: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/s390/include/asm/irq.h
===================================================================
--- linux.orig/arch/s390/include/asm/irq.h	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/include/asm/irq.h	2013-08-22 14:49:17.327583548 -0500
@@ -55,7 +55,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct ir
 
 static __always_inline void inc_irq_stat(enum interruption_class irq)
 {
-	__get_cpu_var(irq_stat).irqs[irq]++;
+	__this_cpu_inc(irq_stat.irqs[irq]);
 }
 
 struct ext_code {
Index: linux/arch/s390/include/asm/cputime.h
===================================================================
--- linux.orig/arch/s390/include/asm/cputime.h	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/include/asm/cputime.h	2013-08-22 14:49:17.327583548 -0500
@@ -187,7 +187,7 @@ cputime64_t s390_get_idle_time(int cpu);
 
 static inline int s390_nohz_delay(int cpu)
 {
-	return __get_cpu_var(s390_idle).nohz_delay != 0;
+	return __this_cpu_read(s390_idle.nohz_delay) != 0;
 }
 
 #define arch_needs_cpu(cpu) s390_nohz_delay(cpu)
Index: linux/arch/s390/kernel/kprobes.c
===================================================================
--- linux.orig/arch/s390/kernel/kprobes.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/kprobes.c	2013-08-22 14:49:17.327583548 -0500
@@ -212,9 +212,9 @@ static void __kprobes disable_singlestep
  */
 static void __kprobes push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p)
 {
-	kcb->prev_kprobe.kp = __get_cpu_var(current_kprobe);
+	kcb->prev_kprobe.kp = __this_cpu_read(current_kprobe);
 	kcb->prev_kprobe.status = kcb->kprobe_status;
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 /*
@@ -224,7 +224,7 @@ static void __kprobes push_kprobe(struct
  */
 static void __kprobes pop_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }
 
@@ -305,7 +305,7 @@ static int __kprobes kprobe_handler(stru
 		enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn);
 		return 1;
 	} else if (kprobe_running()) {
-		p = __get_cpu_var(current_kprobe);
+		p = __this_cpu_read(current_kprobe);
 		if (p->break_handler && p->break_handler(p, regs)) {
 			/*
 			 * Continuation after the jprobe completed and
Index: linux/arch/s390/kernel/nmi.c
===================================================================
--- linux.orig/arch/s390/kernel/nmi.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/nmi.c	2013-08-22 14:49:17.327583548 -0500
@@ -53,8 +53,8 @@ void s390_handle_mcck(void)
 	 */
 	local_irq_save(flags);
 	local_mcck_disable();
-	mcck = __get_cpu_var(cpu_mcck);
-	memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
+	mcck = __this_cpu_read(cpu_mcck);
+	memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(struct mcck_struct));
 	clear_thread_flag(TIF_MCCK_PENDING);
 	local_mcck_enable();
 	local_irq_restore(flags);
@@ -256,7 +256,7 @@ void notrace s390_do_machine_check(struc
 	nmi_enter();
 	inc_irq_stat(NMI_NMI);
 	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
-	mcck = &__get_cpu_var(cpu_mcck);
+	mcck = this_cpu_ptr(&cpu_mcck);
 	umode = user_mode(regs);
 
 	if (mci->sd) {
Index: linux/arch/s390/kernel/perf_cpum_cf.c
===================================================================
--- linux.orig/arch/s390/kernel/perf_cpum_cf.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/perf_cpum_cf.c	2013-08-22 14:49:17.331583508 -0500
@@ -173,7 +173,7 @@ static int validate_ctr_auth(const struc
  */
 static void cpumf_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	int err;
 
 	if (cpuhw->flags & PMU_F_ENABLED)
@@ -196,7 +196,7 @@ static void cpumf_pmu_enable(struct pmu
  */
 static void cpumf_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	int err;
 	u64 inactive;
 
@@ -230,7 +230,7 @@ static void cpumf_measurement_alert(stru
 		return;
 
 	inc_irq_stat(IRQEXT_CMC);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	/* Measurement alerts are shared and might happen when the PMU
 	 * is not reserved.  Ignore these alerts in this case. */
@@ -250,7 +250,7 @@ static void cpumf_measurement_alert(stru
 #define PMC_RELEASE   1
 static void setup_pmc_cpu(void *flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	switch (*((int *) flags)) {
 	case PMC_INIT:
@@ -481,7 +481,7 @@ static void cpumf_pmu_read(struct perf_e
 
 static void cpumf_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
@@ -512,7 +512,7 @@ static void cpumf_pmu_start(struct perf_
 
 static void cpumf_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	if (!(hwc->state & PERF_HES_STOPPED)) {
@@ -533,7 +533,7 @@ static void cpumf_pmu_stop(struct perf_e
 
 static int cpumf_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	/* Check authorization for the counter set to which this
 	 * counter belongs.
@@ -557,7 +557,7 @@ static int cpumf_pmu_add(struct perf_eve
 
 static void cpumf_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	cpumf_pmu_stop(event, PERF_EF_UPDATE);
 
@@ -581,7 +581,7 @@ static void cpumf_pmu_del(struct perf_ev
  */
 static void cpumf_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	perf_pmu_disable(pmu);
 	cpuhw->flags |= PERF_EVENT_TXN;
@@ -595,7 +595,7 @@ static void cpumf_pmu_start_txn(struct p
  */
 static void cpumf_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	WARN_ON(cpuhw->tx_state != cpuhw->state);
 
@@ -610,7 +610,7 @@ static void cpumf_pmu_cancel_txn(struct
  */
 static int cpumf_pmu_commit_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	u64 state;
 
 	/* check if the updated state can be scheduled */
Index: linux/arch/s390/kernel/processor.c
===================================================================
--- linux.orig/arch/s390/kernel/processor.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/processor.c	2013-08-22 14:49:17.331583508 -0500
@@ -23,8 +23,8 @@ static DEFINE_PER_CPU(struct cpuid, cpu_
  */
 void cpu_init(void)
 {
-	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
-	struct cpuid *id = &__get_cpu_var(cpu_id);
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
+	struct cpuid *id = this_cpu_ptr(&cpu_id);
 
 	get_cpu_id(id);
 	atomic_inc(&init_mm.mm_count);
Index: linux/arch/s390/kernel/time.c
===================================================================
--- linux.orig/arch/s390/kernel/time.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/time.c	2013-08-22 14:49:17.331583508 -0500
@@ -93,7 +93,7 @@ void clock_comparator_work(void)
 
 	S390_lowcore.clock_comparator = -1ULL;
 	set_clock_comparator(S390_lowcore.clock_comparator);
-	cd = &__get_cpu_var(comparators);
+	cd = this_cpu_ptr(&comparators);
 	cd->event_handler(cd);
 }
 
@@ -363,7 +363,7 @@ EXPORT_SYMBOL(get_sync_clock);
  */
 static void disable_sync_clock(void *dummy)
 {
-	atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
+	atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
 	/*
 	 * Clear the in-sync bit 2^31. All get_sync_clock calls will
 	 * fail until the sync bit is turned back on. In addition
@@ -380,7 +380,7 @@ static void disable_sync_clock(void *dum
  */
 static void enable_sync_clock(void)
 {
-	atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
+	atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
 	atomic_set_mask(0x80000000, sw_ptr);
 }
 
Index: linux/arch/s390/kernel/vtime.c
===================================================================
--- linux.orig/arch/s390/kernel/vtime.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/vtime.c	2013-08-22 14:49:17.331583508 -0500
@@ -153,7 +153,7 @@ EXPORT_SYMBOL_GPL(vtime_account_system);
 
 void __kprobes vtime_stop_cpu(void)
 {
-	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
 	unsigned long long idle_time;
 	unsigned long psw_mask;
 
Index: linux/arch/s390/oprofile/hwsampler.c
===================================================================
--- linux.orig/arch/s390/oprofile/hwsampler.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/oprofile/hwsampler.c	2013-08-22 14:49:17.331583508 -0500
@@ -228,7 +228,7 @@ static inline unsigned long *trailer_ent
 static void hws_ext_handler(struct ext_code ext_code,
 			    unsigned int param32, unsigned long param64)
 {
-	struct hws_cpu_buffer *cb = &__get_cpu_var(sampler_cpu_buffer);
+	struct hws_cpu_buffer *cb = this_cpu_ptr(&sampler_cpu_buffer);
 
 	if (!(param32 & CPU_MF_INT_SF_MASK))
 		return;
Index: linux/arch/s390/pci/pci.c
===================================================================
--- linux.orig/arch/s390/pci/pci.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/pci/pci.c	2013-08-22 14:49:17.335583467 -0500
@@ -409,7 +409,7 @@ static DEFINE_PER_CPU(unsigned long, nex
 
 static void zpci_irq_handler(struct airq_struct *airq)
 {
-	unsigned long sbit, mbit, last = 0, start = __get_cpu_var(next_sbit);
+	unsigned long sbit, mbit, last = 0, start = __this_cpu_read(next_sbit);
 	int rescan = 0, max = aisb_max;
 	struct zdev_irq_map *imap;
 
@@ -460,7 +460,7 @@ scan:
 	}
 out:
 	/* store next device bit to scan */
-	__get_cpu_var(next_sbit) = (++last >= aisb_max) ? 0 : last;
+	__this_cpu_write(next_sbit, (++last >= aisb_max) ? 0 : last);
 }
 
 /* msi_vecs - number of requested interrupts, 0 place function to error state */
Index: linux/arch/s390/kernel/irq.c
===================================================================
--- linux.orig/arch/s390/kernel/irq.c	2013-08-08 02:54:34.344984334 -0500
+++ linux/arch/s390/kernel/irq.c	2013-08-22 14:53:32.025028108 -0500
@@ -250,7 +250,7 @@ void __irq_entry do_extint(struct pt_reg
 	kstat_incr_irqs_this_cpu(EXTERNAL_INTERRUPT, NULL);
 	ext_code = *(struct ext_code *) &regs->int_code;
 	if (ext_code.code != 0x1004)
-		__get_cpu_var(s390_idle).nohz_delay = 1;
+		__this_cpu_write(s390_idle.nohz_delay, 1);
 
 	index = ext_hash(ext_code.code);
 	rcu_read_lock();

[gcv v3 23/35] s390: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/s390/include/asm/irq.h
===================================================================
--- linux.orig/arch/s390/include/asm/irq.h	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/include/asm/irq.h	2013-08-22 14:49:17.327583548 -0500
@@ -55,7 +55,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct ir
 
 static __always_inline void inc_irq_stat(enum interruption_class irq)
 {
-	__get_cpu_var(irq_stat).irqs[irq]++;
+	__this_cpu_inc(irq_stat.irqs[irq]);
 }
 
 struct ext_code {
Index: linux/arch/s390/include/asm/cputime.h
===================================================================
--- linux.orig/arch/s390/include/asm/cputime.h	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/include/asm/cputime.h	2013-08-22 14:49:17.327583548 -0500
@@ -187,7 +187,7 @@ cputime64_t s390_get_idle_time(int cpu);
 
 static inline int s390_nohz_delay(int cpu)
 {
-	return __get_cpu_var(s390_idle).nohz_delay != 0;
+	return __this_cpu_read(s390_idle.nohz_delay) != 0;
 }
 
 #define arch_needs_cpu(cpu) s390_nohz_delay(cpu)
Index: linux/arch/s390/kernel/kprobes.c
===================================================================
--- linux.orig/arch/s390/kernel/kprobes.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/kprobes.c	2013-08-22 14:49:17.327583548 -0500
@@ -212,9 +212,9 @@ static void __kprobes disable_singlestep
  */
 static void __kprobes push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p)
 {
-	kcb->prev_kprobe.kp = __get_cpu_var(current_kprobe);
+	kcb->prev_kprobe.kp = __this_cpu_read(current_kprobe);
 	kcb->prev_kprobe.status = kcb->kprobe_status;
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 /*
@@ -224,7 +224,7 @@ static void __kprobes push_kprobe(struct
  */
 static void __kprobes pop_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }
 
@@ -305,7 +305,7 @@ static int __kprobes kprobe_handler(stru
 		enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn);
 		return 1;
 	} else if (kprobe_running()) {
-		p = __get_cpu_var(current_kprobe);
+		p = __this_cpu_read(current_kprobe);
 		if (p->break_handler && p->break_handler(p, regs)) {
 			/*
 			 * Continuation after the jprobe completed and
Index: linux/arch/s390/kernel/nmi.c
===================================================================
--- linux.orig/arch/s390/kernel/nmi.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/nmi.c	2013-08-22 14:49:17.327583548 -0500
@@ -53,8 +53,8 @@ void s390_handle_mcck(void)
 	 */
 	local_irq_save(flags);
 	local_mcck_disable();
-	mcck = __get_cpu_var(cpu_mcck);
-	memset(&__get_cpu_var(cpu_mcck), 0, sizeof(struct mcck_struct));
+	mcck = __this_cpu_read(cpu_mcck);
+	memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(struct mcck_struct));
 	clear_thread_flag(TIF_MCCK_PENDING);
 	local_mcck_enable();
 	local_irq_restore(flags);
@@ -256,7 +256,7 @@ void notrace s390_do_machine_check(struc
 	nmi_enter();
 	inc_irq_stat(NMI_NMI);
 	mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
-	mcck = &__get_cpu_var(cpu_mcck);
+	mcck = this_cpu_ptr(&cpu_mcck);
 	umode = user_mode(regs);
 
 	if (mci->sd) {
Index: linux/arch/s390/kernel/perf_cpum_cf.c
===================================================================
--- linux.orig/arch/s390/kernel/perf_cpum_cf.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/perf_cpum_cf.c	2013-08-22 14:49:17.331583508 -0500
@@ -173,7 +173,7 @@ static int validate_ctr_auth(const struc
  */
 static void cpumf_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	int err;
 
 	if (cpuhw->flags & PMU_F_ENABLED)
@@ -196,7 +196,7 @@ static void cpumf_pmu_enable(struct pmu
  */
 static void cpumf_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	int err;
 	u64 inactive;
 
@@ -230,7 +230,7 @@ static void cpumf_measurement_alert(stru
 		return;
 
 	inc_irq_stat(IRQEXT_CMC);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	/* Measurement alerts are shared and might happen when the PMU
 	 * is not reserved.  Ignore these alerts in this case. */
@@ -250,7 +250,7 @@ static void cpumf_measurement_alert(stru
 #define PMC_RELEASE   1
 static void setup_pmc_cpu(void *flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	switch (*((int *) flags)) {
 	case PMC_INIT:
@@ -481,7 +481,7 @@ static void cpumf_pmu_read(struct perf_e
 
 static void cpumf_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
@@ -512,7 +512,7 @@ static void cpumf_pmu_start(struct perf_
 
 static void cpumf_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	if (!(hwc->state & PERF_HES_STOPPED)) {
@@ -533,7 +533,7 @@ static void cpumf_pmu_stop(struct perf_e
 
 static int cpumf_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	/* Check authorization for the counter set to which this
 	 * counter belongs.
@@ -557,7 +557,7 @@ static int cpumf_pmu_add(struct perf_eve
 
 static void cpumf_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	cpumf_pmu_stop(event, PERF_EF_UPDATE);
 
@@ -581,7 +581,7 @@ static void cpumf_pmu_del(struct perf_ev
  */
 static void cpumf_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	perf_pmu_disable(pmu);
 	cpuhw->flags |= PERF_EVENT_TXN;
@@ -595,7 +595,7 @@ static void cpumf_pmu_start_txn(struct p
  */
 static void cpumf_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	WARN_ON(cpuhw->tx_state != cpuhw->state);
 
@@ -610,7 +610,7 @@ static void cpumf_pmu_cancel_txn(struct
  */
 static int cpumf_pmu_commit_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	u64 state;
 
 	/* check if the updated state can be scheduled */
Index: linux/arch/s390/kernel/processor.c
===================================================================
--- linux.orig/arch/s390/kernel/processor.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/processor.c	2013-08-22 14:49:17.331583508 -0500
@@ -23,8 +23,8 @@ static DEFINE_PER_CPU(struct cpuid, cpu_
  */
 void cpu_init(void)
 {
-	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
-	struct cpuid *id = &__get_cpu_var(cpu_id);
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
+	struct cpuid *id = this_cpu_ptr(&cpu_id);
 
 	get_cpu_id(id);
 	atomic_inc(&init_mm.mm_count);
Index: linux/arch/s390/kernel/time.c
===================================================================
--- linux.orig/arch/s390/kernel/time.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/time.c	2013-08-22 14:49:17.331583508 -0500
@@ -93,7 +93,7 @@ void clock_comparator_work(void)
 
 	S390_lowcore.clock_comparator = -1ULL;
 	set_clock_comparator(S390_lowcore.clock_comparator);
-	cd = &__get_cpu_var(comparators);
+	cd = this_cpu_ptr(&comparators);
 	cd->event_handler(cd);
 }
 
@@ -363,7 +363,7 @@ EXPORT_SYMBOL(get_sync_clock);
  */
 static void disable_sync_clock(void *dummy)
 {
-	atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
+	atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
 	/*
 	 * Clear the in-sync bit 2^31. All get_sync_clock calls will
 	 * fail until the sync bit is turned back on. In addition
@@ -380,7 +380,7 @@ static void disable_sync_clock(void *dum
  */
 static void enable_sync_clock(void)
 {
-	atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
+	atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
 	atomic_set_mask(0x80000000, sw_ptr);
 }
 
Index: linux/arch/s390/kernel/vtime.c
===================================================================
--- linux.orig/arch/s390/kernel/vtime.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/kernel/vtime.c	2013-08-22 14:49:17.331583508 -0500
@@ -153,7 +153,7 @@ EXPORT_SYMBOL_GPL(vtime_account_system);
 
 void __kprobes vtime_stop_cpu(void)
 {
-	struct s390_idle_data *idle = &__get_cpu_var(s390_idle);
+	struct s390_idle_data *idle = this_cpu_ptr(&s390_idle);
 	unsigned long long idle_time;
 	unsigned long psw_mask;
 
Index: linux/arch/s390/oprofile/hwsampler.c
===================================================================
--- linux.orig/arch/s390/oprofile/hwsampler.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/oprofile/hwsampler.c	2013-08-22 14:49:17.331583508 -0500
@@ -228,7 +228,7 @@ static inline unsigned long *trailer_ent
 static void hws_ext_handler(struct ext_code ext_code,
 			    unsigned int param32, unsigned long param64)
 {
-	struct hws_cpu_buffer *cb = &__get_cpu_var(sampler_cpu_buffer);
+	struct hws_cpu_buffer *cb = this_cpu_ptr(&sampler_cpu_buffer);
 
 	if (!(param32 & CPU_MF_INT_SF_MASK))
 		return;
Index: linux/arch/s390/pci/pci.c
===================================================================
--- linux.orig/arch/s390/pci/pci.c	2013-08-22 14:49:17.339583428 -0500
+++ linux/arch/s390/pci/pci.c	2013-08-22 14:49:17.335583467 -0500
@@ -409,7 +409,7 @@ static DEFINE_PER_CPU(unsigned long, nex
 
 static void zpci_irq_handler(struct airq_struct *airq)
 {
-	unsigned long sbit, mbit, last = 0, start = __get_cpu_var(next_sbit);
+	unsigned long sbit, mbit, last = 0, start = __this_cpu_read(next_sbit);
 	int rescan = 0, max = aisb_max;
 	struct zdev_irq_map *imap;
 
@@ -460,7 +460,7 @@ scan:
 	}
 out:
 	/* store next device bit to scan */
-	__get_cpu_var(next_sbit) = (++last >= aisb_max) ? 0 : last;
+	__this_cpu_write(next_sbit, (++last >= aisb_max) ? 0 : last);
 }
 
 /* msi_vecs - number of requested interrupts, 0 place function to error state */
Index: linux/arch/s390/kernel/irq.c
===================================================================
--- linux.orig/arch/s390/kernel/irq.c	2013-08-08 02:54:34.344984334 -0500
+++ linux/arch/s390/kernel/irq.c	2013-08-22 14:53:32.025028108 -0500
@@ -250,7 +250,7 @@ void __irq_entry do_extint(struct pt_reg
 	kstat_incr_irqs_this_cpu(EXTERNAL_INTERRUPT, NULL);
 	ext_code = *(struct ext_code *) &regs->int_code;
 	if (ext_code.code != 0x1004)
-		__get_cpu_var(s390_idle).nohz_delay = 1;
+		__this_cpu_write(s390_idle.nohz_delay, 1);
 
 	index = ext_hash(ext_code.code);
 	rcu_read_lock();

[gcv v3 03/35] Coccinelle script for __get_cpu_var conversion

[Christoph Lameter]

Much of the work was done by this coccinelle script.

Wont catch everything (since coccinelle aborts when it no longer can make
sense out of macros, sigh) but it covers a lot of ground.

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/scripts/coccinelle/convert/__get_cpu_var.cocci
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux/scripts/coccinelle/convert/__get_cpu_var.cocci	2013-08-22 14:41:13.976518846 -0500
@@ -0,0 +1,70 @@
+// Convert all &__get_cpu_var to this_cpu_ptr
+//
+// _get_cpu_var is defined as:
+//
+// #define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
+//
+//&__get_cpu_var() is therefore
+//
+//	this_cpu_ptr(&var);
+//
+// The use of this_cpu_ptr() instead of __get_cpu_var clarifies
+// that we are relocating a per cpu offset and that there are
+// no get/put semantics involved.
+//
+//
+// Convert all &__get_cpu_vars (and also related functions)
+// to this_cpu_ptr(). Multiple transformations are provided
+// to be able to beautify the source a bit.
+//
+// Christoph Lameter <cl@linux.com> August 20, 2013
+//
+
+@A@ expression E; @@
+
+...
+-(&__get_cpu_var(E))
++this_cpu_ptr(&E)
+...
+
+@B@ expression E; @@
+
+...
+-(&__raw_get_cpu_var(E))
++__this_cpu_ptr(&E)
+...
+
+@C@ expression E; @@
+
+...
+-&__get_cpu_var(E)
++this_cpu_ptr(&E)
+...
+
+@D@ expression E; @@
+
+...
+-&__raw_get_cpu_var(E)
++__this_cpu_ptr(&E)
+...
+
+@A2@ expression E; @@
+
+-(&__get_cpu_var(E))
++this_cpu_ptr(&E)
+
+@B2@ expression E; @@
+
+-(&__raw_get_cpu_var(E))
++__this_cpu_ptr(&E)
+
+@C2@ expression E; @@
+
+-&__get_cpu_var(E)
++this_cpu_ptr(&E)
+
+@D2@ expression E; @@
+
+-&__raw_get_cpu_var(E)
++__this_cpu_ptr(&E)
+

[gcv v3 03/35] Coccinelle script for __get_cpu_var conversion

[Christoph Lameter]

Much of the work was done by this coccinelle script.

Wont catch everything (since coccinelle aborts when it no longer can make
sense out of macros, sigh) but it covers a lot of ground.

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/scripts/coccinelle/convert/__get_cpu_var.cocci
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ linux/scripts/coccinelle/convert/__get_cpu_var.cocci	2013-08-22 14:41:13.976518846 -0500
@@ -0,0 +1,70 @@
+// Convert all &__get_cpu_var to this_cpu_ptr
+//
+// _get_cpu_var is defined as:
+//
+// #define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
+//
+//&__get_cpu_var() is therefore
+//
+//	this_cpu_ptr(&var);
+//
+// The use of this_cpu_ptr() instead of __get_cpu_var clarifies
+// that we are relocating a per cpu offset and that there are
+// no get/put semantics involved.
+//
+//
+// Convert all &__get_cpu_vars (and also related functions)
+// to this_cpu_ptr(). Multiple transformations are provided
+// to be able to beautify the source a bit.
+//
+// Christoph Lameter <cl@linux.com> August 20, 2013
+//
+
+@A@ expression E; @@
+
+...
+-(&__get_cpu_var(E))
++this_cpu_ptr(&E)
+...
+
+@B@ expression E; @@
+
+...
+-(&__raw_get_cpu_var(E))
++__this_cpu_ptr(&E)
+...
+
+@C@ expression E; @@
+
+...
+-&__get_cpu_var(E)
++this_cpu_ptr(&E)
+...
+
+@D@ expression E; @@
+
+...
+-&__raw_get_cpu_var(E)
++__this_cpu_ptr(&E)
+...
+
+@A2@ expression E; @@
+
+-(&__get_cpu_var(E))
++this_cpu_ptr(&E)
+
+@B2@ expression E; @@
+
+-(&__raw_get_cpu_var(E))
++__this_cpu_ptr(&E)
+
+@C2@ expression E; @@
+
+-&__get_cpu_var(E)
++this_cpu_ptr(&E)
+
+@D2@ expression E; @@
+
+-&__raw_get_cpu_var(E)
++__this_cpu_ptr(&E)
+

[gcv v3 09/35] block: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/block/blk-iopoll.c
===================================================================
--- linux.orig/block/blk-iopoll.c	2013-08-26 14:36:07.858875667 -0500
+++ linux/block/blk-iopoll.c	2013-08-26 14:36:07.850875751 -0500
@@ -35,7 +35,7 @@ void blk_iopoll_sched(struct blk_iopoll
 	unsigned long flags;
 
 	local_irq_save(flags);
-	list_add_tail(&iop->list, &__get_cpu_var(blk_cpu_iopoll));
+	list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll));
 	__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 	local_irq_restore(flags);
 }
@@ -79,7 +79,7 @@ EXPORT_SYMBOL(blk_iopoll_complete);
 
 static void blk_iopoll_softirq(struct softirq_action *h)
 {
-	struct list_head *list = &__get_cpu_var(blk_cpu_iopoll);
+	struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
 	int rearm = 0, budget = blk_iopoll_budget;
 	unsigned long start_time = jiffies;
 
@@ -201,7 +201,7 @@ static int blk_iopoll_cpu_notify(struct
 
 		local_irq_disable();
 		list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
-				 &__get_cpu_var(blk_cpu_iopoll));
+				 this_cpu_ptr(&blk_cpu_iopoll));
 		__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 		local_irq_enable();
 	}
Index: linux/block/blk-softirq.c
===================================================================
--- linux.orig/block/blk-softirq.c	2013-08-26 14:36:07.858875667 -0500
+++ linux/block/blk-softirq.c	2013-08-26 14:36:07.854875709 -0500
@@ -23,7 +23,7 @@ static void blk_done_softirq(struct soft
 	struct list_head *cpu_list, local_list;
 
 	local_irq_disable();
-	cpu_list = &__get_cpu_var(blk_cpu_done);
+	cpu_list = this_cpu_ptr(&blk_cpu_done);
 	list_replace_init(cpu_list, &local_list);
 	local_irq_enable();
 
@@ -44,7 +44,7 @@ static void trigger_softirq(void *data)
 	struct list_head *list;
 
 	local_irq_save(flags);
-	list = &__get_cpu_var(blk_cpu_done);
+	list = this_cpu_ptr(&blk_cpu_done);
 	list_add_tail(&rq->csd.list, list);
 
 	if (list->next == &rq->csd.list)
@@ -90,7 +90,7 @@ static int blk_cpu_notify(struct notifie
 
 		local_irq_disable();
 		list_splice_init(&per_cpu(blk_cpu_done, cpu),
-				 &__get_cpu_var(blk_cpu_done));
+				 this_cpu_ptr(&blk_cpu_done));
 		raise_softirq_irqoff(BLOCK_SOFTIRQ);
 		local_irq_enable();
 	}
@@ -135,7 +135,7 @@ void __blk_complete_request(struct reque
 	if (ccpu == cpu || shared) {
 		struct list_head *list;
 do_local:
-		list = &__get_cpu_var(blk_cpu_done);
+		list = this_cpu_ptr(&blk_cpu_done);
 		list_add_tail(&req->csd.list, list);
 
 		/*
Index: linux/fs/fscache/object.c
===================================================================
--- linux.orig/fs/fscache/object.c	2013-08-26 14:36:07.858875667 -0500
+++ linux/fs/fscache/object.c	2013-08-26 14:36:07.854875709 -0500
@@ -796,7 +796,7 @@ void fscache_enqueue_object(struct fscac
  */
 bool fscache_object_sleep_till_congested(signed long *timeoutp)
 {
-	wait_queue_head_t *cong_wq = &__get_cpu_var(fscache_object_cong_wait);
+	wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait);
 	DEFINE_WAIT(wait);
 
 	if (fscache_object_congested())

[gcv v3 09/35] block: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/block/blk-iopoll.c
===================================================================
--- linux.orig/block/blk-iopoll.c	2013-08-26 14:36:07.858875667 -0500
+++ linux/block/blk-iopoll.c	2013-08-26 14:36:07.850875751 -0500
@@ -35,7 +35,7 @@ void blk_iopoll_sched(struct blk_iopoll
 	unsigned long flags;
 
 	local_irq_save(flags);
-	list_add_tail(&iop->list, &__get_cpu_var(blk_cpu_iopoll));
+	list_add_tail(&iop->list, this_cpu_ptr(&blk_cpu_iopoll));
 	__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 	local_irq_restore(flags);
 }
@@ -79,7 +79,7 @@ EXPORT_SYMBOL(blk_iopoll_complete);
 
 static void blk_iopoll_softirq(struct softirq_action *h)
 {
-	struct list_head *list = &__get_cpu_var(blk_cpu_iopoll);
+	struct list_head *list = this_cpu_ptr(&blk_cpu_iopoll);
 	int rearm = 0, budget = blk_iopoll_budget;
 	unsigned long start_time = jiffies;
 
@@ -201,7 +201,7 @@ static int blk_iopoll_cpu_notify(struct
 
 		local_irq_disable();
 		list_splice_init(&per_cpu(blk_cpu_iopoll, cpu),
-				 &__get_cpu_var(blk_cpu_iopoll));
+				 this_cpu_ptr(&blk_cpu_iopoll));
 		__raise_softirq_irqoff(BLOCK_IOPOLL_SOFTIRQ);
 		local_irq_enable();
 	}
Index: linux/block/blk-softirq.c
===================================================================
--- linux.orig/block/blk-softirq.c	2013-08-26 14:36:07.858875667 -0500
+++ linux/block/blk-softirq.c	2013-08-26 14:36:07.854875709 -0500
@@ -23,7 +23,7 @@ static void blk_done_softirq(struct soft
 	struct list_head *cpu_list, local_list;
 
 	local_irq_disable();
-	cpu_list = &__get_cpu_var(blk_cpu_done);
+	cpu_list = this_cpu_ptr(&blk_cpu_done);
 	list_replace_init(cpu_list, &local_list);
 	local_irq_enable();
 
@@ -44,7 +44,7 @@ static void trigger_softirq(void *data)
 	struct list_head *list;
 
 	local_irq_save(flags);
-	list = &__get_cpu_var(blk_cpu_done);
+	list = this_cpu_ptr(&blk_cpu_done);
 	list_add_tail(&rq->csd.list, list);
 
 	if (list->next == &rq->csd.list)
@@ -90,7 +90,7 @@ static int blk_cpu_notify(struct notifie
 
 		local_irq_disable();
 		list_splice_init(&per_cpu(blk_cpu_done, cpu),
-				 &__get_cpu_var(blk_cpu_done));
+				 this_cpu_ptr(&blk_cpu_done));
 		raise_softirq_irqoff(BLOCK_SOFTIRQ);
 		local_irq_enable();
 	}
@@ -135,7 +135,7 @@ void __blk_complete_request(struct reque
 	if (ccpu == cpu || shared) {
 		struct list_head *list;
 do_local:
-		list = &__get_cpu_var(blk_cpu_done);
+		list = this_cpu_ptr(&blk_cpu_done);
 		list_add_tail(&req->csd.list, list);
 
 		/*
Index: linux/fs/fscache/object.c
===================================================================
--- linux.orig/fs/fscache/object.c	2013-08-26 14:36:07.858875667 -0500
+++ linux/fs/fscache/object.c	2013-08-26 14:36:07.854875709 -0500
@@ -796,7 +796,7 @@ void fscache_enqueue_object(struct fscac
  */
 bool fscache_object_sleep_till_congested(signed long *timeoutp)
 {
-	wait_queue_head_t *cong_wq = &__get_cpu_var(fscache_object_cong_wait);
+	wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait);
 	DEFINE_WAIT(wait);
 
 	if (fscache_object_congested())

[gcv v3 18/35] drivers/leds: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/leds/trigger/ledtrig-cpu.c
===================================================================
--- linux.orig/drivers/leds/trigger/ledtrig-cpu.c	2013-08-27 14:46:42.043176071 -0500
+++ linux/drivers/leds/trigger/ledtrig-cpu.c	2013-08-27 14:46:42.035176153 -0500
@@ -46,7 +46,7 @@ static DEFINE_PER_CPU(struct led_trigger
  */
 void ledtrig_cpu(enum cpu_led_event ledevt)
 {
-	struct led_trigger_cpu *trig = &__get_cpu_var(cpu_trig);
+	struct led_trigger_cpu *trig = this_cpu_ptr(&cpu_trig);
 
 	/* Locate the correct CPU LED */
 	switch (ledevt) {

Re: [gcv v3 18/35] drivers/leds: Replace __get_cpu_var uses

[Bryan Wu]

On Wed, Aug 28, 2013 at 12:48 PM, Christoph Lameter <cl@linux.com> wrote:
> __get_cpu_var() is used for multiple purposes in the kernel source. One of them is
> address calculation via the form &__get_cpu_var(x). This calculates the address for
> the instance of the percpu variable of the current processor based on an offset.
>
> Other use cases are for storing and retrieving data from the current processors percpu area.
> __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.
>
> __get_cpu_var() is defined as :
>
>
> #define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
>
>
>
> __get_cpu_var() always only does an address determination. However, store and retrieve operations
> could use a segment prefix (or global register on other platforms) to avoid the address calculation.
>
> this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
> optimized assembly code to read and write per cpu variables.
>
>
> This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
> or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
> and less registers are used when code is generated.
>
> At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.
>
> The patchset includes passes over all arches as well. Once these operations are used throughout then
> specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
> f.e. using a global register that may be set to the per cpu base.
>
>
>
>
> Transformations done to __get_cpu_var()
>
>
> 1. Determine the address of the percpu instance of the current processor.
>
>         DEFINE_PER_CPU(int, y);
>         int *x = &__get_cpu_var(y);
>
>     Converts to
>
>         int *x = this_cpu_ptr(&y);
>
>
> 2. Same as #1 but this time an array structure is involved.
>
>         DEFINE_PER_CPU(int, y[20]);
>         int *x = __get_cpu_var(y);
>
>     Converts to
>
>         int *x = this_cpu_ptr(y);
>
>
> 3. Retrieve the content of the current processors instance of a per cpu variable.
>
>         DEFINE_PER_CPU(int, u);
>         int x = __get_cpu_var(y)
>
>    Converts to
>
>         int x = __this_cpu_read(y);
>
>
> 4. Retrieve the content of a percpu struct
>
>         DEFINE_PER_CPU(struct mystruct, y);
>         struct mystruct x = __get_cpu_var(y);
>
>    Converts to
>
>         memcpy(this_cpu_ptr(&x), y, sizeof(x));
>
>
> 5. Assignment to a per cpu variable
>
>         DEFINE_PER_CPU(int, y)
>         __get_cpu_var(y) = x;
>
>    Converts to
>
>         this_cpu_write(y, x);
>
>
> 6. Increment/Decrement etc of a per cpu variable
>
>         DEFINE_PER_CPU(int, y);
>         __get_cpu_var(y)++
>
>    Converts to
>
>         this_cpu_inc(y)
>
>
>
> Signed-off-by: Christoph Lameter <cl@linux.com>
>
> Index: linux/drivers/leds/trigger/ledtrig-cpu.c
> ===================================================================
> --- linux.orig/drivers/leds/trigger/ledtrig-cpu.c       2013-08-27 14:46:42.043176071 -0500
> +++ linux/drivers/leds/trigger/ledtrig-cpu.c    2013-08-27 14:46:42.035176153 -0500
> @@ -46,7 +46,7 @@ static DEFINE_PER_CPU(struct led_trigger
>   */
>  void ledtrig_cpu(enum cpu_led_event ledevt)
>  {
> -       struct led_trigger_cpu *trig = &__get_cpu_var(cpu_trig);
> +       struct led_trigger_cpu *trig = this_cpu_ptr(&cpu_trig);
>

Sure, please go ahead with my ack.

Acked-by: Bryan Wu <cooloney@gmail.com>

>         /* Locate the correct CPU LED */
>         switch (ledevt) {
>

[gcv v3 22/35] mips: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/mips/include/asm/fpu_emulator.h
===================================================================
--- linux.orig/arch/mips/include/asm/fpu_emulator.h	2013-08-22 14:18:23.138568266 -0500
+++ linux/arch/mips/include/asm/fpu_emulator.h	2013-08-22 14:18:23.130568348 -0500
@@ -43,7 +43,7 @@ DECLARE_PER_CPU(struct mips_fpu_emulator
 #define MIPS_FPU_EMU_INC_STATS(M)					\
 do {									\
 	preempt_disable();						\
-	__local_inc(&__get_cpu_var(fpuemustats).M);			\
+	__this_cpu_inc(fpuemustats.M);					\
 	preempt_enable();						\
 } while (0)
 
Index: linux/arch/mips/cavium-octeon/octeon-irq.c
===================================================================
--- linux.orig/arch/mips/cavium-octeon/octeon-irq.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/cavium-octeon/octeon-irq.c	2013-08-22 14:18:54.210250887 -0500
@@ -264,13 +264,13 @@ static void octeon_irq_ciu_enable_local(
 	unsigned long *pen;
 	unsigned long flags;
 	union octeon_ciu_chip_data cd;
-	raw_spinlock_t *lock = &__get_cpu_var(octeon_irq_ciu_spinlock);
+	raw_spinlock_t *lock = this_cpu_ptr(&octeon_irq_ciu_spinlock);
 
 	cd.p = irq_data_get_irq_chip_data(data);
 
 	raw_spin_lock_irqsave(lock, flags);
 	if (cd.s.line == 0) {
-		pen = &__get_cpu_var(octeon_irq_ciu0_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu0_en_mirror);
 		__set_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -279,7 +279,7 @@ static void octeon_irq_ciu_enable_local(
 		wmb();
 		cvmx_write_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2), *pen);
 	} else {
-		pen = &__get_cpu_var(octeon_irq_ciu1_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu1_en_mirror);
 		__set_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -296,13 +296,13 @@ static void octeon_irq_ciu_disable_local
 	unsigned long *pen;
 	unsigned long flags;
 	union octeon_ciu_chip_data cd;
-	raw_spinlock_t *lock = &__get_cpu_var(octeon_irq_ciu_spinlock);
+	raw_spinlock_t *lock = this_cpu_ptr(&octeon_irq_ciu_spinlock);
 
 	cd.p = irq_data_get_irq_chip_data(data);
 
 	raw_spin_lock_irqsave(lock, flags);
 	if (cd.s.line == 0) {
-		pen = &__get_cpu_var(octeon_irq_ciu0_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu0_en_mirror);
 		__clear_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -311,7 +311,7 @@ static void octeon_irq_ciu_disable_local
 		wmb();
 		cvmx_write_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2), *pen);
 	} else {
-		pen = &__get_cpu_var(octeon_irq_ciu1_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu1_en_mirror);
 		__clear_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -431,11 +431,11 @@ static void octeon_irq_ciu_enable_local_
 
 	if (cd.s.line == 0) {
 		int index = cvmx_get_core_num() * 2;
-		set_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu0_en_mirror));
+		set_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu0_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN0_W1S(index), mask);
 	} else {
 		int index = cvmx_get_core_num() * 2 + 1;
-		set_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu1_en_mirror));
+		set_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu1_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN1_W1S(index), mask);
 	}
 }
@@ -450,11 +450,11 @@ static void octeon_irq_ciu_disable_local
 
 	if (cd.s.line == 0) {
 		int index = cvmx_get_core_num() * 2;
-		clear_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu0_en_mirror));
+		clear_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu0_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN0_W1C(index), mask);
 	} else {
 		int index = cvmx_get_core_num() * 2 + 1;
-		clear_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu1_en_mirror));
+		clear_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu1_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN1_W1C(index), mask);
 	}
 }
@@ -1063,7 +1063,7 @@ static void octeon_irq_ip2_ciu(void)
 	const unsigned long core_id = cvmx_get_core_num();
 	u64 ciu_sum = cvmx_read_csr(CVMX_CIU_INTX_SUM0(core_id * 2));
 
-	ciu_sum &= __get_cpu_var(octeon_irq_ciu0_en_mirror);
+	ciu_sum &= __this_cpu_read(octeon_irq_ciu0_en_mirror);
 	if (likely(ciu_sum)) {
 		int bit = fls64(ciu_sum) - 1;
 		int irq = octeon_irq_ciu_to_irq[0][bit];
@@ -1080,7 +1080,7 @@ static void octeon_irq_ip3_ciu(void)
 {
 	u64 ciu_sum = cvmx_read_csr(CVMX_CIU_INT_SUM1);
 
-	ciu_sum &= __get_cpu_var(octeon_irq_ciu1_en_mirror);
+	ciu_sum &= __this_cpu_read(octeon_irq_ciu1_en_mirror);
 	if (likely(ciu_sum)) {
 		int bit = fls64(ciu_sum) - 1;
 		int irq = octeon_irq_ciu_to_irq[1][bit];
@@ -1129,10 +1129,10 @@ static void octeon_irq_init_ciu_percpu(v
 	int coreid = cvmx_get_core_num();
 
 
-	__get_cpu_var(octeon_irq_ciu0_en_mirror) = 0;
-	__get_cpu_var(octeon_irq_ciu1_en_mirror) = 0;
+	__this_cpu_write(octeon_irq_ciu0_en_mirror, 0);
+	__this_cpu_write(octeon_irq_ciu1_en_mirror, 0);
 	wmb();
-	raw_spin_lock_init(&__get_cpu_var(octeon_irq_ciu_spinlock));
+	raw_spin_lock_init(this_cpu_ptr(&octeon_irq_ciu_spinlock));
 	/*
 	 * Disable All CIU Interrupts. The ones we need will be
 	 * enabled later.  Read the SUM register so we know the write
Index: linux/arch/mips/kernel/kprobes.c
===================================================================
--- linux.orig/arch/mips/kernel/kprobes.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/kernel/kprobes.c	2013-08-22 14:18:54.210250887 -0500
@@ -224,7 +224,7 @@ static void save_previous_kprobe(struct
 
 static void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_old_SR = kcb->prev_kprobe.old_SR;
 	kcb->kprobe_saved_SR = kcb->prev_kprobe.saved_SR;
@@ -234,7 +234,7 @@ static void restore_previous_kprobe(stru
 static void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 			       struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_saved_SR = kcb->kprobe_old_SR = (regs->cp0_status & ST0_IE);
 	kcb->kprobe_saved_epc = regs->cp0_epc;
 }
@@ -385,7 +385,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs))
 				goto ss_probe;
 		}
Index: linux/arch/mips/kernel/perf_event_mipsxx.c
===================================================================
--- linux.orig/arch/mips/kernel/perf_event_mipsxx.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/kernel/perf_event_mipsxx.c	2013-08-22 14:18:54.210250887 -0500
@@ -340,7 +340,7 @@ static int mipsxx_pmu_alloc_counter(stru
 
 static void mipsxx_pmu_enable_event(struct hw_perf_event *evt, int idx)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	WARN_ON(idx < 0 || idx >= mipspmu.num_counters);
 
@@ -360,7 +360,7 @@ static void mipsxx_pmu_enable_event(stru
 
 static void mipsxx_pmu_disable_event(int idx)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long flags;
 
 	WARN_ON(idx < 0 || idx >= mipspmu.num_counters);
@@ -460,7 +460,7 @@ static void mipspmu_stop(struct perf_eve
 
 static int mipspmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx;
 	int err = 0;
@@ -496,7 +496,7 @@ out:
 
 static void mipspmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -1270,7 +1270,7 @@ static int __hw_perf_event_init(struct p
 
 static void pause_local_counters(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int ctr = mipspmu.num_counters;
 	unsigned long flags;
 
@@ -1286,7 +1286,7 @@ static void pause_local_counters(void)
 
 static void resume_local_counters(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int ctr = mipspmu.num_counters;
 
 	do {
@@ -1297,7 +1297,7 @@ static void resume_local_counters(void)
 
 static int mipsxx_pmu_handle_shared_irq(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_sample_data data;
 	unsigned int counters = mipspmu.num_counters;
 	u64 counter;
Index: linux/arch/mips/kernel/smp-bmips.c
===================================================================
--- linux.orig/arch/mips/kernel/smp-bmips.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/kernel/smp-bmips.c	2013-08-22 14:18:54.214250846 -0500
@@ -304,7 +304,7 @@ static irqreturn_t bmips_ipi_interrupt(i
 	int action, cpu = irq - IPI0_IRQ;
 
 	spin_lock_irqsave(&ipi_lock, flags);
-	action = __get_cpu_var(ipi_action_mask);
+	action = __this_cpu_read(ipi_action_mask);
 	per_cpu(ipi_action_mask, cpu) = 0;
 	clear_c0_cause(cpu ? C_SW1 : C_SW0);
 	spin_unlock_irqrestore(&ipi_lock, flags);

[gcv v3 22/35] mips: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/mips/include/asm/fpu_emulator.h
===================================================================
--- linux.orig/arch/mips/include/asm/fpu_emulator.h	2013-08-22 14:18:23.138568266 -0500
+++ linux/arch/mips/include/asm/fpu_emulator.h	2013-08-22 14:18:23.130568348 -0500
@@ -43,7 +43,7 @@ DECLARE_PER_CPU(struct mips_fpu_emulator
 #define MIPS_FPU_EMU_INC_STATS(M)					\
 do {									\
 	preempt_disable();						\
-	__local_inc(&__get_cpu_var(fpuemustats).M);			\
+	__this_cpu_inc(fpuemustats.M);					\
 	preempt_enable();						\
 } while (0)
 
Index: linux/arch/mips/cavium-octeon/octeon-irq.c
===================================================================
--- linux.orig/arch/mips/cavium-octeon/octeon-irq.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/cavium-octeon/octeon-irq.c	2013-08-22 14:18:54.210250887 -0500
@@ -264,13 +264,13 @@ static void octeon_irq_ciu_enable_local(
 	unsigned long *pen;
 	unsigned long flags;
 	union octeon_ciu_chip_data cd;
-	raw_spinlock_t *lock = &__get_cpu_var(octeon_irq_ciu_spinlock);
+	raw_spinlock_t *lock = this_cpu_ptr(&octeon_irq_ciu_spinlock);
 
 	cd.p = irq_data_get_irq_chip_data(data);
 
 	raw_spin_lock_irqsave(lock, flags);
 	if (cd.s.line == 0) {
-		pen = &__get_cpu_var(octeon_irq_ciu0_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu0_en_mirror);
 		__set_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -279,7 +279,7 @@ static void octeon_irq_ciu_enable_local(
 		wmb();
 		cvmx_write_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2), *pen);
 	} else {
-		pen = &__get_cpu_var(octeon_irq_ciu1_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu1_en_mirror);
 		__set_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -296,13 +296,13 @@ static void octeon_irq_ciu_disable_local
 	unsigned long *pen;
 	unsigned long flags;
 	union octeon_ciu_chip_data cd;
-	raw_spinlock_t *lock = &__get_cpu_var(octeon_irq_ciu_spinlock);
+	raw_spinlock_t *lock = this_cpu_ptr(&octeon_irq_ciu_spinlock);
 
 	cd.p = irq_data_get_irq_chip_data(data);
 
 	raw_spin_lock_irqsave(lock, flags);
 	if (cd.s.line == 0) {
-		pen = &__get_cpu_var(octeon_irq_ciu0_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu0_en_mirror);
 		__clear_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -311,7 +311,7 @@ static void octeon_irq_ciu_disable_local
 		wmb();
 		cvmx_write_csr(CVMX_CIU_INTX_EN0(cvmx_get_core_num() * 2), *pen);
 	} else {
-		pen = &__get_cpu_var(octeon_irq_ciu1_en_mirror);
+		pen = this_cpu_ptr(&octeon_irq_ciu1_en_mirror);
 		__clear_bit(cd.s.bit, pen);
 		/*
 		 * Must be visible to octeon_irq_ip{2,3}_ciu() before
@@ -431,11 +431,11 @@ static void octeon_irq_ciu_enable_local_
 
 	if (cd.s.line == 0) {
 		int index = cvmx_get_core_num() * 2;
-		set_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu0_en_mirror));
+		set_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu0_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN0_W1S(index), mask);
 	} else {
 		int index = cvmx_get_core_num() * 2 + 1;
-		set_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu1_en_mirror));
+		set_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu1_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN1_W1S(index), mask);
 	}
 }
@@ -450,11 +450,11 @@ static void octeon_irq_ciu_disable_local
 
 	if (cd.s.line == 0) {
 		int index = cvmx_get_core_num() * 2;
-		clear_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu0_en_mirror));
+		clear_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu0_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN0_W1C(index), mask);
 	} else {
 		int index = cvmx_get_core_num() * 2 + 1;
-		clear_bit(cd.s.bit, &__get_cpu_var(octeon_irq_ciu1_en_mirror));
+		clear_bit(cd.s.bit, this_cpu_ptr(&octeon_irq_ciu1_en_mirror));
 		cvmx_write_csr(CVMX_CIU_INTX_EN1_W1C(index), mask);
 	}
 }
@@ -1063,7 +1063,7 @@ static void octeon_irq_ip2_ciu(void)
 	const unsigned long core_id = cvmx_get_core_num();
 	u64 ciu_sum = cvmx_read_csr(CVMX_CIU_INTX_SUM0(core_id * 2));
 
-	ciu_sum &= __get_cpu_var(octeon_irq_ciu0_en_mirror);
+	ciu_sum &= __this_cpu_read(octeon_irq_ciu0_en_mirror);
 	if (likely(ciu_sum)) {
 		int bit = fls64(ciu_sum) - 1;
 		int irq = octeon_irq_ciu_to_irq[0][bit];
@@ -1080,7 +1080,7 @@ static void octeon_irq_ip3_ciu(void)
 {
 	u64 ciu_sum = cvmx_read_csr(CVMX_CIU_INT_SUM1);
 
-	ciu_sum &= __get_cpu_var(octeon_irq_ciu1_en_mirror);
+	ciu_sum &= __this_cpu_read(octeon_irq_ciu1_en_mirror);
 	if (likely(ciu_sum)) {
 		int bit = fls64(ciu_sum) - 1;
 		int irq = octeon_irq_ciu_to_irq[1][bit];
@@ -1129,10 +1129,10 @@ static void octeon_irq_init_ciu_percpu(v
 	int coreid = cvmx_get_core_num();
 
 
-	__get_cpu_var(octeon_irq_ciu0_en_mirror) = 0;
-	__get_cpu_var(octeon_irq_ciu1_en_mirror) = 0;
+	__this_cpu_write(octeon_irq_ciu0_en_mirror, 0);
+	__this_cpu_write(octeon_irq_ciu1_en_mirror, 0);
 	wmb();
-	raw_spin_lock_init(&__get_cpu_var(octeon_irq_ciu_spinlock));
+	raw_spin_lock_init(this_cpu_ptr(&octeon_irq_ciu_spinlock));
 	/*
 	 * Disable All CIU Interrupts. The ones we need will be
 	 * enabled later.  Read the SUM register so we know the write
Index: linux/arch/mips/kernel/kprobes.c
===================================================================
--- linux.orig/arch/mips/kernel/kprobes.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/kernel/kprobes.c	2013-08-22 14:18:54.210250887 -0500
@@ -224,7 +224,7 @@ static void save_previous_kprobe(struct
 
 static void restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_old_SR = kcb->prev_kprobe.old_SR;
 	kcb->kprobe_saved_SR = kcb->prev_kprobe.saved_SR;
@@ -234,7 +234,7 @@ static void restore_previous_kprobe(stru
 static void set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 			       struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_saved_SR = kcb->kprobe_old_SR = (regs->cp0_status & ST0_IE);
 	kcb->kprobe_saved_epc = regs->cp0_epc;
 }
@@ -385,7 +385,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs))
 				goto ss_probe;
 		}
Index: linux/arch/mips/kernel/perf_event_mipsxx.c
===================================================================
--- linux.orig/arch/mips/kernel/perf_event_mipsxx.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/kernel/perf_event_mipsxx.c	2013-08-22 14:18:54.210250887 -0500
@@ -340,7 +340,7 @@ static int mipsxx_pmu_alloc_counter(stru
 
 static void mipsxx_pmu_enable_event(struct hw_perf_event *evt, int idx)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	WARN_ON(idx < 0 || idx >= mipspmu.num_counters);
 
@@ -360,7 +360,7 @@ static void mipsxx_pmu_enable_event(stru
 
 static void mipsxx_pmu_disable_event(int idx)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long flags;
 
 	WARN_ON(idx < 0 || idx >= mipspmu.num_counters);
@@ -460,7 +460,7 @@ static void mipspmu_stop(struct perf_eve
 
 static int mipspmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx;
 	int err = 0;
@@ -496,7 +496,7 @@ out:
 
 static void mipspmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -1270,7 +1270,7 @@ static int __hw_perf_event_init(struct p
 
 static void pause_local_counters(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int ctr = mipspmu.num_counters;
 	unsigned long flags;
 
@@ -1286,7 +1286,7 @@ static void pause_local_counters(void)
 
 static void resume_local_counters(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int ctr = mipspmu.num_counters;
 
 	do {
@@ -1297,7 +1297,7 @@ static void resume_local_counters(void)
 
 static int mipsxx_pmu_handle_shared_irq(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_sample_data data;
 	unsigned int counters = mipspmu.num_counters;
 	u64 counter;
Index: linux/arch/mips/kernel/smp-bmips.c
===================================================================
--- linux.orig/arch/mips/kernel/smp-bmips.c	2013-08-22 14:17:32.000000000 -0500
+++ linux/arch/mips/kernel/smp-bmips.c	2013-08-22 14:18:54.214250846 -0500
@@ -304,7 +304,7 @@ static irqreturn_t bmips_ipi_interrupt(i
 	int action, cpu = irq - IPI0_IRQ;
 
 	spin_lock_irqsave(&ipi_lock, flags);
-	action = __get_cpu_var(ipi_action_mask);
+	action = __this_cpu_read(ipi_action_mask);
 	per_cpu(ipi_action_mask, cpu) = 0;
 	clear_c0_cause(cpu ? C_SW1 : C_SW0);
 	spin_unlock_irqrestore(&ipi_lock, flags);

[gcv v3 12/35] watchdog: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/watchdog.c
===================================================================
--- linux.orig/kernel/watchdog.c	2013-08-26 14:28:39.000000000 -0500
+++ linux/kernel/watchdog.c	2013-08-26 14:29:34.471034451 -0500
@@ -174,8 +174,8 @@ EXPORT_SYMBOL(touch_nmi_watchdog);
 
 void touch_softlockup_watchdog_sync(void)
 {
-	__raw_get_cpu_var(softlockup_touch_sync) = true;
-	__raw_get_cpu_var(watchdog_touch_ts) = 0;
+	__this_cpu_write(softlockup_touch_sync, 1);
+	__this_cpu_write(watchdog_touch_ts, 0);
 }
 
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
@@ -341,7 +341,7 @@ static void watchdog_set_prio(unsigned i
 
 static void watchdog_enable(unsigned int cpu)
 {
-	struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);
+	struct hrtimer *hrtimer = __this_cpu_ptr(&watchdog_hrtimer);
 
 	/* kick off the timer for the hardlockup detector */
 	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
@@ -361,7 +361,7 @@ static void watchdog_enable(unsigned int
 
 static void watchdog_disable(unsigned int cpu)
 {
-	struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);
+	struct hrtimer *hrtimer = __this_cpu_ptr(&watchdog_hrtimer);
 
 	watchdog_set_prio(SCHED_NORMAL, 0);
 	hrtimer_cancel(hrtimer);

[gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/linux/kernel_stat.h
===================================================================
--- linux.orig/include/linux/kernel_stat.h	2013-08-26 14:21:39.000000000 -0500
+++ linux/include/linux/kernel_stat.h	2013-08-26 14:23:08.883120293 -0500
@@ -47,8 +47,8 @@ DECLARE_PER_CPU(struct kernel_stat, ksta
 DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
 
 /* Must have preemption disabled for this to be meaningful. */
-#define kstat_this_cpu (&__get_cpu_var(kstat))
-#define kcpustat_this_cpu (&__get_cpu_var(kernel_cpustat))
+#define kstat_this_cpu this_cpu_ptr(&kstat)
+#define kcpustat_this_cpu this_cpu_ptr(&kernel_cpustat)
 #define kstat_cpu(cpu) per_cpu(kstat, cpu)
 #define kcpustat_cpu(cpu) per_cpu(kernel_cpustat, cpu)
 
Index: linux/kernel/events/callchain.c
===================================================================
--- linux.orig/kernel/events/callchain.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/events/callchain.c	2013-08-26 14:23:08.875120379 -0500
@@ -134,7 +134,7 @@ static struct perf_callchain_entry *get_
 	int cpu;
 	struct callchain_cpus_entries *entries;
 
-	*rctx = get_recursion_context(__get_cpu_var(callchain_recursion));
+	*rctx = get_recursion_context(this_cpu_ptr(callchain_recursion));
 	if (*rctx == -1)
 		return NULL;
 
@@ -150,7 +150,7 @@ static struct perf_callchain_entry *get_
 static void
 put_callchain_entry(int rctx)
 {
-	put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
+	put_recursion_context(this_cpu_ptr(callchain_recursion), rctx);
 }
 
 struct perf_callchain_entry *
Index: linux/kernel/events/core.c
===================================================================
--- linux.orig/kernel/events/core.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/events/core.c	2013-08-26 14:23:08.875120379 -0500
@@ -238,10 +238,10 @@ void perf_sample_event_took(u64 sample_l
 		return;
 
 	/* decay the counter by 1 average sample */
-	local_samples_len = __get_cpu_var(running_sample_length);
+	local_samples_len = __this_cpu_read(running_sample_length);
 	local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES;
 	local_samples_len += sample_len_ns;
-	__get_cpu_var(running_sample_length) = local_samples_len;
+	__this_cpu_write(running_sample_length, local_samples_len);
 
 	/*
 	 * note: this will be biased artifically low until we have
@@ -865,7 +865,7 @@ static DEFINE_PER_CPU(struct list_head,
 static void perf_pmu_rotate_start(struct pmu *pmu)
 {
 	struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
-	struct list_head *head = &__get_cpu_var(rotation_list);
+	struct list_head *head = this_cpu_ptr(&rotation_list);
 
 	WARN_ON(!irqs_disabled());
 
@@ -2321,7 +2321,7 @@ void __perf_event_task_sched_out(struct
 	 * to check if we have to switch out PMU state.
 	 * cgroup event are system-wide mode only
 	 */
-	if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
+	if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
 		perf_cgroup_sched_out(task, next);
 }
 
@@ -2566,11 +2566,11 @@ void __perf_event_task_sched_in(struct t
 	 * to check if we have to switch in PMU state.
 	 * cgroup event are system-wide mode only
 	 */
-	if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
+	if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
 		perf_cgroup_sched_in(prev, task);
 
 	/* check for system-wide branch_stack events */
-	if (atomic_read(&__get_cpu_var(perf_branch_stack_events)))
+	if (atomic_read(this_cpu_ptr(&perf_branch_stack_events)))
 		perf_branch_stack_sched_in(prev, task);
 }
 
@@ -2811,7 +2811,7 @@ done:
 #ifdef CONFIG_NO_HZ_FULL
 bool perf_event_can_stop_tick(void)
 {
-	if (list_empty(&__get_cpu_var(rotation_list)))
+	if (list_empty(this_cpu_ptr(&rotation_list)))
 		return true;
 	else
 		return false;
@@ -2820,7 +2820,7 @@ bool perf_event_can_stop_tick(void)
 
 void perf_event_task_tick(void)
 {
-	struct list_head *head = &__get_cpu_var(rotation_list);
+	struct list_head *head = this_cpu_ptr(&rotation_list);
 	struct perf_cpu_context *cpuctx, *tmp;
 	struct perf_event_context *ctx;
 	int throttled;
@@ -5414,7 +5414,7 @@ static void do_perf_sw_event(enum perf_t
 				    struct perf_sample_data *data,
 				    struct pt_regs *regs)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 	struct perf_event *event;
 	struct hlist_head *head;
 
@@ -5433,7 +5433,7 @@ end:
 
 int perf_swevent_get_recursion_context(void)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 
 	return get_recursion_context(swhash->recursion);
 }
@@ -5441,7 +5441,7 @@ EXPORT_SYMBOL_GPL(perf_swevent_get_recur
 
 inline void perf_swevent_put_recursion_context(int rctx)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 
 	put_recursion_context(swhash->recursion, rctx);
 }
@@ -5470,7 +5470,7 @@ static void perf_swevent_read(struct per
 
 static int perf_swevent_add(struct perf_event *event, int flags)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 	struct hw_perf_event *hwc = &event->hw;
 	struct hlist_head *head;
 
Index: linux/kernel/sched/cputime.c
===================================================================
--- linux.orig/kernel/sched/cputime.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/cputime.c	2013-08-26 14:23:08.879120335 -0500
@@ -121,7 +121,7 @@ static inline void task_group_account_fi
 	 * is the only cgroup, then nothing else should be necessary.
 	 *
 	 */
-	__get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
+	__this_cpu_add(kernel_cpustat.cpustat[index], tmp);
 
 	cpuacct_account_field(p, index, tmp);
 }
Index: linux/kernel/sched/fair.c
===================================================================
--- linux.orig/kernel/sched/fair.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/fair.c	2013-08-26 14:23:08.879120335 -0500
@@ -5057,7 +5057,7 @@ static int load_balance(int this_cpu, st
 	struct sched_group *group;
 	struct rq *busiest;
 	unsigned long flags;
-	struct cpumask *cpus = __get_cpu_var(load_balance_mask);
+	struct cpumask *cpus = this_cpu_ptr(load_balance_mask);
 
 	struct lb_env env = {
 		.sd		= sd,
Index: linux/kernel/sched/rt.c
===================================================================
--- linux.orig/kernel/sched/rt.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/rt.c	2013-08-26 14:23:08.883120293 -0500
@@ -1389,7 +1389,7 @@ static DEFINE_PER_CPU(cpumask_var_t, loc
 static int find_lowest_rq(struct task_struct *task)
 {
 	struct sched_domain *sd;
-	struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
+	struct cpumask *lowest_mask = this_cpu_ptr(local_cpu_mask);
 	int this_cpu = smp_processor_id();
 	int cpu      = task_cpu(task);
 
Index: linux/kernel/sched/sched.h
===================================================================
--- linux.orig/kernel/sched/sched.h	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/sched.h	2013-08-26 14:23:08.883120293 -0500
@@ -538,10 +538,10 @@ static inline int cpu_of(struct rq *rq)
 DECLARE_PER_CPU(struct rq, runqueues);
 
 #define cpu_rq(cpu)		(&per_cpu(runqueues, (cpu)))
-#define this_rq()		(&__get_cpu_var(runqueues))
+#define this_rq()		this_cpu_ptr(&runqueues)
 #define task_rq(p)		cpu_rq(task_cpu(p))
 #define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
-#define raw_rq()		(&__raw_get_cpu_var(runqueues))
+#define raw_rq()		__this_cpu_ptr(&runqueues)
 
 static inline u64 rq_clock(struct rq *rq)
 {
Index: linux/kernel/user-return-notifier.c
===================================================================
--- linux.orig/kernel/user-return-notifier.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/user-return-notifier.c	2013-08-26 14:23:08.883120293 -0500
@@ -14,7 +14,7 @@ static DEFINE_PER_CPU(struct hlist_head,
 void user_return_notifier_register(struct user_return_notifier *urn)
 {
 	set_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
-	hlist_add_head(&urn->link, &__get_cpu_var(return_notifier_list));
+	hlist_add_head(&urn->link, this_cpu_ptr(&return_notifier_list));
 }
 EXPORT_SYMBOL_GPL(user_return_notifier_register);
 
@@ -25,7 +25,7 @@ EXPORT_SYMBOL_GPL(user_return_notifier_r
 void user_return_notifier_unregister(struct user_return_notifier *urn)
 {
 	hlist_del(&urn->link);
-	if (hlist_empty(&__get_cpu_var(return_notifier_list)))
+	if (hlist_empty(this_cpu_ptr(&return_notifier_list)))
 		clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
 }
 EXPORT_SYMBOL_GPL(user_return_notifier_unregister);

[gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/linux/kernel_stat.h
===================================================================
--- linux.orig/include/linux/kernel_stat.h	2013-08-26 14:21:39.000000000 -0500
+++ linux/include/linux/kernel_stat.h	2013-08-26 14:23:08.883120293 -0500
@@ -47,8 +47,8 @@ DECLARE_PER_CPU(struct kernel_stat, ksta
 DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
 
 /* Must have preemption disabled for this to be meaningful. */
-#define kstat_this_cpu (&__get_cpu_var(kstat))
-#define kcpustat_this_cpu (&__get_cpu_var(kernel_cpustat))
+#define kstat_this_cpu this_cpu_ptr(&kstat)
+#define kcpustat_this_cpu this_cpu_ptr(&kernel_cpustat)
 #define kstat_cpu(cpu) per_cpu(kstat, cpu)
 #define kcpustat_cpu(cpu) per_cpu(kernel_cpustat, cpu)
 
Index: linux/kernel/events/callchain.c
===================================================================
--- linux.orig/kernel/events/callchain.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/events/callchain.c	2013-08-26 14:23:08.875120379 -0500
@@ -134,7 +134,7 @@ static struct perf_callchain_entry *get_
 	int cpu;
 	struct callchain_cpus_entries *entries;
 
-	*rctx = get_recursion_context(__get_cpu_var(callchain_recursion));
+	*rctx = get_recursion_context(this_cpu_ptr(callchain_recursion));
 	if (*rctx == -1)
 		return NULL;
 
@@ -150,7 +150,7 @@ static struct perf_callchain_entry *get_
 static void
 put_callchain_entry(int rctx)
 {
-	put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
+	put_recursion_context(this_cpu_ptr(callchain_recursion), rctx);
 }
 
 struct perf_callchain_entry *
Index: linux/kernel/events/core.c
===================================================================
--- linux.orig/kernel/events/core.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/events/core.c	2013-08-26 14:23:08.875120379 -0500
@@ -238,10 +238,10 @@ void perf_sample_event_took(u64 sample_l
 		return;
 
 	/* decay the counter by 1 average sample */
-	local_samples_len = __get_cpu_var(running_sample_length);
+	local_samples_len = __this_cpu_read(running_sample_length);
 	local_samples_len -= local_samples_len/NR_ACCUMULATED_SAMPLES;
 	local_samples_len += sample_len_ns;
-	__get_cpu_var(running_sample_length) = local_samples_len;
+	__this_cpu_write(running_sample_length, local_samples_len);
 
 	/*
 	 * note: this will be biased artifically low until we have
@@ -865,7 +865,7 @@ static DEFINE_PER_CPU(struct list_head,
 static void perf_pmu_rotate_start(struct pmu *pmu)
 {
 	struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
-	struct list_head *head = &__get_cpu_var(rotation_list);
+	struct list_head *head = this_cpu_ptr(&rotation_list);
 
 	WARN_ON(!irqs_disabled());
 
@@ -2321,7 +2321,7 @@ void __perf_event_task_sched_out(struct
 	 * to check if we have to switch out PMU state.
 	 * cgroup event are system-wide mode only
 	 */
-	if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
+	if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
 		perf_cgroup_sched_out(task, next);
 }
 
@@ -2566,11 +2566,11 @@ void __perf_event_task_sched_in(struct t
 	 * to check if we have to switch in PMU state.
 	 * cgroup event are system-wide mode only
 	 */
-	if (atomic_read(&__get_cpu_var(perf_cgroup_events)))
+	if (atomic_read(this_cpu_ptr(&perf_cgroup_events)))
 		perf_cgroup_sched_in(prev, task);
 
 	/* check for system-wide branch_stack events */
-	if (atomic_read(&__get_cpu_var(perf_branch_stack_events)))
+	if (atomic_read(this_cpu_ptr(&perf_branch_stack_events)))
 		perf_branch_stack_sched_in(prev, task);
 }
 
@@ -2811,7 +2811,7 @@ done:
 #ifdef CONFIG_NO_HZ_FULL
 bool perf_event_can_stop_tick(void)
 {
-	if (list_empty(&__get_cpu_var(rotation_list)))
+	if (list_empty(this_cpu_ptr(&rotation_list)))
 		return true;
 	else
 		return false;
@@ -2820,7 +2820,7 @@ bool perf_event_can_stop_tick(void)
 
 void perf_event_task_tick(void)
 {
-	struct list_head *head = &__get_cpu_var(rotation_list);
+	struct list_head *head = this_cpu_ptr(&rotation_list);
 	struct perf_cpu_context *cpuctx, *tmp;
 	struct perf_event_context *ctx;
 	int throttled;
@@ -5414,7 +5414,7 @@ static void do_perf_sw_event(enum perf_t
 				    struct perf_sample_data *data,
 				    struct pt_regs *regs)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 	struct perf_event *event;
 	struct hlist_head *head;
 
@@ -5433,7 +5433,7 @@ end:
 
 int perf_swevent_get_recursion_context(void)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 
 	return get_recursion_context(swhash->recursion);
 }
@@ -5441,7 +5441,7 @@ EXPORT_SYMBOL_GPL(perf_swevent_get_recur
 
 inline void perf_swevent_put_recursion_context(int rctx)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 
 	put_recursion_context(swhash->recursion, rctx);
 }
@@ -5470,7 +5470,7 @@ static void perf_swevent_read(struct per
 
 static int perf_swevent_add(struct perf_event *event, int flags)
 {
-	struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
+	struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
 	struct hw_perf_event *hwc = &event->hw;
 	struct hlist_head *head;
 
Index: linux/kernel/sched/cputime.c
===================================================================
--- linux.orig/kernel/sched/cputime.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/cputime.c	2013-08-26 14:23:08.879120335 -0500
@@ -121,7 +121,7 @@ static inline void task_group_account_fi
 	 * is the only cgroup, then nothing else should be necessary.
 	 *
 	 */
-	__get_cpu_var(kernel_cpustat).cpustat[index] += tmp;
+	__this_cpu_add(kernel_cpustat.cpustat[index], tmp);
 
 	cpuacct_account_field(p, index, tmp);
 }
Index: linux/kernel/sched/fair.c
===================================================================
--- linux.orig/kernel/sched/fair.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/fair.c	2013-08-26 14:23:08.879120335 -0500
@@ -5057,7 +5057,7 @@ static int load_balance(int this_cpu, st
 	struct sched_group *group;
 	struct rq *busiest;
 	unsigned long flags;
-	struct cpumask *cpus = __get_cpu_var(load_balance_mask);
+	struct cpumask *cpus = this_cpu_ptr(load_balance_mask);
 
 	struct lb_env env = {
 		.sd		= sd,
Index: linux/kernel/sched/rt.c
===================================================================
--- linux.orig/kernel/sched/rt.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/rt.c	2013-08-26 14:23:08.883120293 -0500
@@ -1389,7 +1389,7 @@ static DEFINE_PER_CPU(cpumask_var_t, loc
 static int find_lowest_rq(struct task_struct *task)
 {
 	struct sched_domain *sd;
-	struct cpumask *lowest_mask = __get_cpu_var(local_cpu_mask);
+	struct cpumask *lowest_mask = this_cpu_ptr(local_cpu_mask);
 	int this_cpu = smp_processor_id();
 	int cpu      = task_cpu(task);
 
Index: linux/kernel/sched/sched.h
===================================================================
--- linux.orig/kernel/sched/sched.h	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/sched/sched.h	2013-08-26 14:23:08.883120293 -0500
@@ -538,10 +538,10 @@ static inline int cpu_of(struct rq *rq)
 DECLARE_PER_CPU(struct rq, runqueues);
 
 #define cpu_rq(cpu)		(&per_cpu(runqueues, (cpu)))
-#define this_rq()		(&__get_cpu_var(runqueues))
+#define this_rq()		this_cpu_ptr(&runqueues)
 #define task_rq(p)		cpu_rq(task_cpu(p))
 #define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
-#define raw_rq()		(&__raw_get_cpu_var(runqueues))
+#define raw_rq()		__this_cpu_ptr(&runqueues)
 
 static inline u64 rq_clock(struct rq *rq)
 {
Index: linux/kernel/user-return-notifier.c
===================================================================
--- linux.orig/kernel/user-return-notifier.c	2013-08-26 14:21:39.000000000 -0500
+++ linux/kernel/user-return-notifier.c	2013-08-26 14:23:08.883120293 -0500
@@ -14,7 +14,7 @@ static DEFINE_PER_CPU(struct hlist_head,
 void user_return_notifier_register(struct user_return_notifier *urn)
 {
 	set_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
-	hlist_add_head(&urn->link, &__get_cpu_var(return_notifier_list));
+	hlist_add_head(&urn->link, this_cpu_ptr(&return_notifier_list));
 }
 EXPORT_SYMBOL_GPL(user_return_notifier_register);
 
@@ -25,7 +25,7 @@ EXPORT_SYMBOL_GPL(user_return_notifier_r
 void user_return_notifier_unregister(struct user_return_notifier *urn)
 {
 	hlist_del(&urn->link);
-	if (hlist_empty(&__get_cpu_var(return_notifier_list)))
+	if (hlist_empty(this_cpu_ptr(&return_notifier_list)))
 		clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
 }
 EXPORT_SYMBOL_GPL(user_return_notifier_unregister);

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Peter Zijlstra]

On Wed, Aug 28, 2013 at 07:48:14PM +0000, Christoph Lameter wrote:
> Transformations done to __get_cpu_var()
> 
> 
> 1. Determine the address of the percpu instance of the current processor.
> 
> 	DEFINE_PER_CPU(int, y);
> 	int *x = &__get_cpu_var(y);
> 
>     Converts to
> 
> 	int *x = this_cpu_ptr(&y);
> 
> 
> 2. Same as #1 but this time an array structure is involved.
> 
> 	DEFINE_PER_CPU(int, y[20]);
> 	int *x = __get_cpu_var(y);
> 
>     Converts to
> 
> 	int *x = this_cpu_ptr(y);
> 
> 
> 3. Retrieve the content of the current processors instance of a per cpu variable.
> 
> 	DEFINE_PER_CPU(int, u);
> 	int x = __get_cpu_var(y)
> 
>    Converts to
> 
> 	int x = __this_cpu_read(y);
> 

This looses a preemption debug check, so NAK

> 4. Retrieve the content of a percpu struct
> 
> 	DEFINE_PER_CPU(struct mystruct, y);
> 	struct mystruct x = __get_cpu_var(y);
> 
>    Converts to
> 
> 	memcpy(this_cpu_ptr(&x), y, sizeof(x));
> 
> 5. Assignment to a per cpu variable
> 
> 	DEFINE_PER_CPU(int, y)
> 	__get_cpu_var(y) = x;
> 
>    Converts to
> 
> 	this_cpu_write(y, x);
> 

This too looses a preemption debug check, NAK

> 6. Increment/Decrement etc of a per cpu variable
> 
> 	DEFINE_PER_CPU(int, y);
> 	__get_cpu_var(y)++
> 
>    Converts to
> 
> 	this_cpu_inc(y)
> 

Lo and behold.. no preemption checks again.


Seriously first fix the debug and validation bits of the *this_cpu*
stuff.

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Ingo Molnar]

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Wed, Aug 28, 2013 at 07:48:14PM +0000, Christoph Lameter wrote:
> > Transformations done to __get_cpu_var()
> > 
> > 
> > 1. Determine the address of the percpu instance of the current processor.
> > 
> > 	DEFINE_PER_CPU(int, y);
> > 	int *x = &__get_cpu_var(y);
> > 
> >     Converts to
> > 
> > 	int *x = this_cpu_ptr(&y);
> > 
> > 
> > 2. Same as #1 but this time an array structure is involved.
> > 
> > 	DEFINE_PER_CPU(int, y[20]);
> > 	int *x = __get_cpu_var(y);
> > 
> >     Converts to
> > 
> > 	int *x = this_cpu_ptr(y);
> > 
> > 
> > 3. Retrieve the content of the current processors instance of a per cpu variable.
> > 
> > 	DEFINE_PER_CPU(int, u);
> > 	int x = __get_cpu_var(y)
> > 
> >    Converts to
> > 
> > 	int x = __this_cpu_read(y);
> > 
> 
> This looses a preemption debug check, so NAK
> 
> > 4. Retrieve the content of a percpu struct
> > 
> > 	DEFINE_PER_CPU(struct mystruct, y);
> > 	struct mystruct x = __get_cpu_var(y);
> > 
> >    Converts to
> > 
> > 	memcpy(this_cpu_ptr(&x), y, sizeof(x));
> > 
> > 5. Assignment to a per cpu variable
> > 
> > 	DEFINE_PER_CPU(int, y)
> > 	__get_cpu_var(y) = x;
> > 
> >    Converts to
> > 
> > 	this_cpu_write(y, x);
> > 
> 
> This too looses a preemption debug check, NAK
> 
> > 6. Increment/Decrement etc of a per cpu variable
> > 
> > 	DEFINE_PER_CPU(int, y);
> > 	__get_cpu_var(y)++
> > 
> >    Converts to
> > 
> > 	this_cpu_inc(y)
> > 
> 
> Lo and behold.. no preemption checks again.
> 
> 
> Seriously first fix the debug and validation bits of the *this_cpu* 
> stuff.

Note that most of the other 'gcv' patches have these problems as well, so 
it's a NAK from me as well for most of the other patches as well ...

Thanks,

	Ingo

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 29 Aug 2013, Ingo Molnar wrote:

>
> >
> >
> > Seriously first fix the debug and validation bits of the *this_cpu*
> > stuff.
>
> Note that most of the other 'gcv' patches have these problems as well, so
> it's a NAK from me as well for most of the other patches as well ...

Note that this only affects __this_cpu_read and __this_cpu_write not the
this_cpu_ptr() operation.

The objection against having other variants of this_cpu operations before
was that there were too many. If we want to reintroduce the preemption
checks in the __ operations then we would need another variant for those
places that do not need it.

Right now we only have the regular ops which are interrupt safe and the
unsafe variant that can be used anyplace.

We could add a ____this_cpu variant that would be used in the cases we do
not want preemption checks? There should not be too many but it will
mean a whole lot of new definitions in percpu.h.

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Steven Rostedt]

On Thu, Aug 29, 2013 at 04:57:43PM +0000, Christoph Lameter wrote:
> 
> We could add a ____this_cpu variant that would be used in the cases we do
> not want preemption checks? There should not be too many but it will
> mean a whole lot of new definitions in percpu.h.

Let's get away from underscores as they are meaningless.

A this_cpu_atomic() or other descriptive name would be much more
appropriate.

-- Steve

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 29 Aug 2013, Steven Rostedt wrote:

> On Thu, Aug 29, 2013 at 04:57:43PM +0000, Christoph Lameter wrote:
> >
> > We could add a ____this_cpu variant that would be used in the cases we do
> > not want preemption checks? There should not be too many but it will
> > mean a whole lot of new definitions in percpu.h.
>
> Let's get away from underscores as they are meaningless.
>
> A this_cpu_atomic() or other descriptive name would be much more
> appropriate.

Its not really an atomic operation in the classic sense.

this_cpu_no_preempt_check_read ?

The problem that I have is also that a kernel with preemption is not
something that see anywhere these days. Looks more like an academic
exercise? Does this really matter? All the distro I see use
PREEMPT_VOLUNTARY. Performance degradation is significant if massive
amounts of checks and preempt disable/enable points are added to the
kernel.

Do we agree that it is necessary and useful to add another variant of
this_cpu ops for this? The concern of having too many variants is no
longer there? Adding another variant is not that difficult just code
intensive.

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Steven Rostedt]

On Thu, 29 Aug 2013 18:15:43 +0000
Christoph Lameter <cl@linux.com> wrote:

> On Thu, 29 Aug 2013, Steven Rostedt wrote:
> 
> Its not really an atomic operation in the classic sense.

It doesn't need to be atomic, it could mean it is used within atomic
locations. Basically, "can't be interrupted here". I just said
"something like", it didn't even need to be that.

> 
> this_cpu_no_preempt_check_read ?

I would make it much shorter. You could use "raw_this_cpu_read()",
which usually means "no checks here". Or, "this_cpu_read_nopreempt()".

> 
> The problem that I have is also that a kernel with preemption is not
> something that see anywhere these days. Looks more like an academic
> exercise? Does this really matter? All the distro I see use

Um, my paycheck depends on PREEMPT_RT working. And there's a lot of
interest in real PREEMPT by audio folks. It's no more an
academic exercise than people wanting really low kernel latency.

> PREEMPT_VOLUNTARY. Performance degradation is significant if massive
> amounts of checks and preempt disable/enable points are added to the
> kernel.

They are usually disabled for production systems. But we run a bunch of
tests with the debug checks enabled, which catch bugs before we ship a
kernel for a production system.

> 
> Do we agree that it is necessary and useful to add another variant of
> this_cpu ops for this? The concern of having too many variants is no
> longer there? Adding another variant is not that difficult just code
> intensive.

How many places use the this_cpu_*() without preemption disabled? I
wouldn't think there's many. I never complained about another variant,
so you need to ask those that have. The tough question for me is what
that variant name should be ;-)

-- Steve

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Steven Rostedt]

On Thu, 29 Aug 2013 18:15:43 +0000
Christoph Lameter <cl@linux.com> wrote:

> On Thu, 29 Aug 2013, Steven Rostedt wrote:
> 
> Its not really an atomic operation in the classic sense.

It doesn't need to be atomic, it could mean it is used within atomic
locations. Basically, "can't be interrupted here". I just said
"something like", it didn't even need to be that.

> 
> this_cpu_no_preempt_check_read ?

I would make it much shorter. You could use "raw_this_cpu_read()",
which usually means "no checks here". Or, "this_cpu_read_nopreempt()".

> 
> The problem that I have is also that a kernel with preemption is not
> something that see anywhere these days. Looks more like an academic
> exercise? Does this really matter? All the distro I see use

Um, my paycheck depends on PREEMPT_RT working. And there's a lot of
interest in real PREEMPT by audio folks. It's no more an
academic exercise than people wanting really low kernel latency.

> PREEMPT_VOLUNTARY. Performance degradation is significant if massive
> amounts of checks and preempt disable/enable points are added to the
> kernel.

They are usually disabled for production systems. But we run a bunch of
tests with the debug checks enabled, which catch bugs before we ship a
kernel for a production system.

> 
> Do we agree that it is necessary and useful to add another variant of
> this_cpu ops for this? The concern of having too many variants is no
> longer there? Adding another variant is not that difficult just code
> intensive.

How many places use the this_cpu_*() without preemption disabled? I
wouldn't think there's many. I never complained about another variant,
so you need to ask those that have. The tough question for me is what
that variant name should be ;-)

-- Steve

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 29 Aug 2013, Steven Rostedt wrote:

> How many places use the this_cpu_*() without preemption disabled? I
> wouldn't think there's many. I never complained about another variant,
> so you need to ask those that have. The tough question for me is what
> that variant name should be ;-)

Tried to add preemption checks but the basic issue is that many of the
checks themselves use this_cpu_ops. percpu.h is very basic to the
operation of fundamental primitives for preempt etc. Use of a BUG_ON needs
a seris of includes in percpu.h that cause more trouble.

If I switch __this_cpu ops to check for preemption then the logic for
preemption etc must use the raw_this_cpu ops.

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Frederic Weisbecker]

2013/9/3 Christoph Lameter <cl@linux.com>:
> On Thu, 29 Aug 2013, Steven Rostedt wrote:
>
>> How many places use the this_cpu_*() without preemption disabled? I
>> wouldn't think there's many. I never complained about another variant,
>> so you need to ask those that have. The tough question for me is what
>> that variant name should be ;-)
>
> Tried to add preemption checks but the basic issue is that many of the
> checks themselves use this_cpu_ops. percpu.h is very basic to the
> operation of fundamental primitives for preempt etc. Use of a BUG_ON needs
> a seris of includes in percpu.h that cause more trouble.
>
> If I switch __this_cpu ops to check for preemption then the logic for
> preemption etc must use the raw_this_cpu ops.

IIUC the issue is that preempt debug checks themselves use per cpu
operations that can result in preempt debug checks? Hence a recursion.
Do you have an example of that?

Also in this case this must be fixed anyway given the checks that
already exist in smp_processor_id(), __get_cpu_var(), ...

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Steven Rostedt]

On Tue, 3 Sep 2013 16:45:45 +0200
Frederic Weisbecker <fweisbec@gmail.com> wrote:

> 2013/9/3 Christoph Lameter <cl@linux.com>:
> > On Thu, 29 Aug 2013, Steven Rostedt wrote:
> >
> >> How many places use the this_cpu_*() without preemption disabled? I
> >> wouldn't think there's many. I never complained about another variant,
> >> so you need to ask those that have. The tough question for me is what
> >> that variant name should be ;-)
> >
> > Tried to add preemption checks but the basic issue is that many of the
> > checks themselves use this_cpu_ops. percpu.h is very basic to the
> > operation of fundamental primitives for preempt etc. Use of a BUG_ON needs
> > a seris of includes in percpu.h that cause more trouble.
> >
> > If I switch __this_cpu ops to check for preemption then the logic for
> > preemption etc must use the raw_this_cpu ops.
> 
> IIUC the issue is that preempt debug checks themselves use per cpu
> operations that can result in preempt debug checks? Hence a recursion.
> Do you have an example of that?
> 
> Also in this case this must be fixed anyway given the checks that
> already exist in smp_processor_id(), __get_cpu_var(), ...

Right, that's why there's a raw_smp_processor_id() and
__raw_get_cpu_var(). Those two are the ones without checks, and they
are called by the non "raw" versions after the check is done.

Really, what's so damn hard about this?

-- Steve

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Christoph Lameter]

On Tue, 3 Sep 2013, Steven Rostedt wrote:

> Right, that's why there's a raw_smp_processor_id() and
> __raw_get_cpu_var(). Those two are the ones without checks, and they
> are called by the non "raw" versions after the check is done.
>
> Really, what's so damn hard about this?

Well you tried it before as far as I can recall. Just came back from Labor
day.  Should have something soon.

Re: [gcv v3 06/35] scheduler: Replace __get_cpu_var uses

[Ingo Molnar]

* Christoph Lameter <cl@linux.com> wrote:

> On Thu, 29 Aug 2013, Steven Rostedt wrote:
> 
> > On Thu, Aug 29, 2013 at 04:57:43PM +0000, Christoph Lameter wrote:
> > >
> > > We could add a ____this_cpu variant that would be used in the cases we do
> > > not want preemption checks? There should not be too many but it will
> > > mean a whole lot of new definitions in percpu.h.
> >
> > Let's get away from underscores as they are meaningless.
> >
> > A this_cpu_atomic() or other descriptive name would be much more
> > appropriate.
> 
> Its not really an atomic operation in the classic sense.
> 
> this_cpu_no_preempt_check_read ?
> 
> The problem that I have is also that a kernel with preemption is not 
> something that see anywhere these days. Looks more like an academic 
> exercise? Does this really matter? All the distro I see use 
> PREEMPT_VOLUNTARY. Performance degradation is significant if massive 
> amounts of checks and preempt disable/enable points are added to the 
> kernel.
> 
> Do we agree that it is necessary and useful to add another variant of 
> this_cpu ops for this? The concern of having too many variants is no 
> longer there? Adding another variant is not that difficult just code 
> intensive.

Just stop the lame excuses and fix it already. This has come up in the 
past and you know it: you were told to fix the this_cpu debug checks by 
Linus as well, yet you didn't ... Don't send crap you know is broken.

Thanks,

	Ingo

[gcv v3 04/35] net: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/net/core/dev.c
===================================================================
--- linux.orig/net/core/dev.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/core/dev.c	2013-08-26 14:18:37.214005168 -0500
@@ -2129,7 +2129,7 @@ static inline void __netif_reschedule(st
 	unsigned long flags;
 
 	local_irq_save(flags);
-	sd = &__get_cpu_var(softnet_data);
+	sd = this_cpu_ptr(&softnet_data);
 	q->next_sched = NULL;
 	*sd->output_queue_tailp = q;
 	sd->output_queue_tailp = &q->next_sched;
@@ -2151,7 +2151,7 @@ void dev_kfree_skb_irq(struct sk_buff *s
 		unsigned long flags;
 
 		local_irq_save(flags);
-		sd = &__get_cpu_var(softnet_data);
+		sd = this_cpu_ptr(&softnet_data);
 		skb->next = sd->completion_queue;
 		sd->completion_queue = skb;
 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
@@ -3111,7 +3111,7 @@ static void rps_trigger_softirq(void *da
 static int rps_ipi_queued(struct softnet_data *sd)
 {
 #ifdef CONFIG_RPS
-	struct softnet_data *mysd = &__get_cpu_var(softnet_data);
+	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
 
 	if (sd != mysd) {
 		sd->rps_ipi_next = mysd->rps_ipi_list;
@@ -3138,7 +3138,7 @@ static bool skb_flow_limit(struct sk_buf
 	if (qlen < (netdev_max_backlog >> 1))
 		return false;
 
-	sd = &__get_cpu_var(softnet_data);
+	sd = this_cpu_ptr(&softnet_data);
 
 	rcu_read_lock();
 	fl = rcu_dereference(sd->flow_limit);
@@ -3280,7 +3280,7 @@ EXPORT_SYMBOL(netif_rx_ni);
 
 static void net_tx_action(struct softirq_action *h)
 {
-	struct softnet_data *sd = &__get_cpu_var(softnet_data);
+	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 
 	if (sd->completion_queue) {
 		struct sk_buff *clist;
@@ -3700,7 +3700,7 @@ EXPORT_SYMBOL(netif_receive_skb);
 static void flush_backlog(void *arg)
 {
 	struct net_device *dev = arg;
-	struct softnet_data *sd = &__get_cpu_var(softnet_data);
+	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 	struct sk_buff *skb, *tmp;
 
 	rps_lock(sd);
@@ -4146,7 +4146,7 @@ void __napi_schedule(struct napi_struct
 	unsigned long flags;
 
 	local_irq_save(flags);
-	____napi_schedule(&__get_cpu_var(softnet_data), n);
+	____napi_schedule(this_cpu_ptr(&softnet_data), n);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL(__napi_schedule);
@@ -4274,7 +4274,7 @@ EXPORT_SYMBOL(netif_napi_del);
 
 static void net_rx_action(struct softirq_action *h)
 {
-	struct softnet_data *sd = &__get_cpu_var(softnet_data);
+	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 	unsigned long time_limit = jiffies + 2;
 	int budget = netdev_budget;
 	void *have;
Index: linux/net/core/drop_monitor.c
===================================================================
--- linux.orig/net/core/drop_monitor.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/core/drop_monitor.c	2013-08-26 14:18:37.218005126 -0500
@@ -142,7 +142,7 @@ static void trace_drop_common(struct sk_
 	unsigned long flags;
 
 	local_irq_save(flags);
-	data = &__get_cpu_var(dm_cpu_data);
+	data = this_cpu_ptr(&dm_cpu_data);
 	spin_lock(&data->lock);
 	dskb = data->skb;
 
Index: linux/net/core/skbuff.c
===================================================================
--- linux.orig/net/core/skbuff.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/core/skbuff.c	2013-08-26 14:18:37.218005126 -0500
@@ -371,7 +371,7 @@ static void *__netdev_alloc_frag(unsigne
 	unsigned long flags;
 
 	local_irq_save(flags);
-	nc = &__get_cpu_var(netdev_alloc_cache);
+	nc = this_cpu_ptr(&netdev_alloc_cache);
 	if (unlikely(!nc->frag.page)) {
 refill:
 		for (order = NETDEV_FRAG_PAGE_MAX_ORDER; ;) {
Index: linux/net/ipv4/syncookies.c
===================================================================
--- linux.orig/net/ipv4/syncookies.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/ipv4/syncookies.c	2013-08-26 14:18:37.210005210 -0500
@@ -44,7 +44,7 @@ static DEFINE_PER_CPU(__u32 [16 + 5 + SH
 static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
 		       u32 count, int c)
 {
-	__u32 *tmp = __get_cpu_var(ipv4_cookie_scratch);
+	__u32 *tmp = this_cpu_ptr(ipv4_cookie_scratch);
 
 	memcpy(tmp + 4, syncookie_secret[c], sizeof(syncookie_secret[c]));
 	tmp[0] = (__force u32)saddr;
Index: linux/net/ipv4/tcp_output.c
===================================================================
--- linux.orig/net/ipv4/tcp_output.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/ipv4/tcp_output.c	2013-08-26 14:18:37.218005126 -0500
@@ -810,7 +810,7 @@ void tcp_wfree(struct sk_buff *skb)
 
 		/* queue this socket to tasklet queue */
 		local_irq_save(flags);
-		tsq = &__get_cpu_var(tsq_tasklet);
+		tsq = this_cpu_ptr(&tsq_tasklet);
 		list_add(&tp->tsq_node, &tsq->head);
 		tasklet_schedule(&tsq->tasklet);
 		local_irq_restore(flags);
Index: linux/net/ipv6/syncookies.c
===================================================================
--- linux.orig/net/ipv6/syncookies.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/ipv6/syncookies.c	2013-08-26 14:18:37.214005168 -0500
@@ -66,7 +66,7 @@ static DEFINE_PER_CPU(__u32 [16 + 5 + SH
 static u32 cookie_hash(const struct in6_addr *saddr, const struct in6_addr *daddr,
 		       __be16 sport, __be16 dport, u32 count, int c)
 {
-	__u32 *tmp = __get_cpu_var(ipv6_cookie_scratch);
+	__u32 *tmp = this_cpu_ptr(ipv6_cookie_scratch);
 
 	/*
 	 * we have 320 bits of information to hash, copy in the remaining
Index: linux/net/rds/ib_rdma.c
===================================================================
--- linux.orig/net/rds/ib_rdma.c	2013-08-26 14:16:59.000000000 -0500
+++ linux/net/rds/ib_rdma.c	2013-08-26 14:18:37.218005126 -0500
@@ -267,7 +267,7 @@ static inline struct rds_ib_mr *rds_ib_r
 	unsigned long *flag;
 
 	preempt_disable();
-	flag = &__get_cpu_var(clean_list_grace);
+	flag = this_cpu_ptr(&clean_list_grace);
 	set_bit(CLEAN_LIST_BUSY_BIT, flag);
 	ret = llist_del_first(&pool->clean_list);
 	if (ret)
Index: linux/include/net/netfilter/nf_conntrack.h
===================================================================
--- linux.orig/include/net/netfilter/nf_conntrack.h	2013-08-26 14:23:46.000000000 -0500
+++ linux/include/net/netfilter/nf_conntrack.h	2013-08-26 14:24:17.190395755 -0500
@@ -243,7 +243,7 @@ extern s16 (*nf_ct_nat_offset)(const str
 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 static inline struct nf_conn *nf_ct_untracked_get(void)
 {
-	return &__raw_get_cpu_var(nf_conntrack_untracked);
+	return __this_cpu_ptr(&nf_conntrack_untracked);
 }
 extern void nf_ct_untracked_status_or(unsigned long bits);
 

[gcv v3 16/35] drivers/oprofile: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/oprofile/cpu_buffer.c
===================================================================
--- linux.orig/drivers/oprofile/cpu_buffer.c	2013-08-27 14:36:45.000000000 -0500
+++ linux/drivers/oprofile/cpu_buffer.c	2013-08-27 14:37:04.284928047 -0500
@@ -45,7 +45,7 @@ unsigned long oprofile_get_cpu_buffer_si
 
 void oprofile_cpu_buffer_inc_smpl_lost(void)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 
 	cpu_buf->sample_lost_overflow++;
 }
@@ -297,7 +297,7 @@ __oprofile_add_ext_sample(unsigned long
 			  unsigned long event, int is_kernel,
 			  struct task_struct *task)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 	unsigned long backtrace = oprofile_backtrace_depth;
 
 	/*
@@ -357,7 +357,7 @@ oprofile_write_reserve(struct op_entry *
 {
 	struct op_sample *sample;
 	int is_kernel = !user_mode(regs);
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 
 	cpu_buf->sample_received++;
 
@@ -412,13 +412,13 @@ int oprofile_write_commit(struct op_entr
 
 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 	log_sample(cpu_buf, pc, 0, is_kernel, event, NULL);
 }
 
 void oprofile_add_trace(unsigned long pc)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 
 	if (!cpu_buf->tracing)
 		return;
Index: linux/drivers/oprofile/timer_int.c
===================================================================
--- linux.orig/drivers/oprofile/timer_int.c	2013-08-27 14:36:45.000000000 -0500
+++ linux/drivers/oprofile/timer_int.c	2013-08-27 14:37:04.284928047 -0500
@@ -32,7 +32,7 @@ static enum hrtimer_restart oprofile_hrt
 
 static void __oprofile_hrtimer_start(void *unused)
 {
-	struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
+	struct hrtimer *hrtimer = this_cpu_ptr(&oprofile_hrtimer);
 
 	if (!ctr_running)
 		return;

[gcv v3 16/35] drivers/oprofile: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/oprofile/cpu_buffer.c
===================================================================
--- linux.orig/drivers/oprofile/cpu_buffer.c	2013-08-27 14:36:45.000000000 -0500
+++ linux/drivers/oprofile/cpu_buffer.c	2013-08-27 14:37:04.284928047 -0500
@@ -45,7 +45,7 @@ unsigned long oprofile_get_cpu_buffer_si
 
 void oprofile_cpu_buffer_inc_smpl_lost(void)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 
 	cpu_buf->sample_lost_overflow++;
 }
@@ -297,7 +297,7 @@ __oprofile_add_ext_sample(unsigned long
 			  unsigned long event, int is_kernel,
 			  struct task_struct *task)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 	unsigned long backtrace = oprofile_backtrace_depth;
 
 	/*
@@ -357,7 +357,7 @@ oprofile_write_reserve(struct op_entry *
 {
 	struct op_sample *sample;
 	int is_kernel = !user_mode(regs);
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 
 	cpu_buf->sample_received++;
 
@@ -412,13 +412,13 @@ int oprofile_write_commit(struct op_entr
 
 void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 	log_sample(cpu_buf, pc, 0, is_kernel, event, NULL);
 }
 
 void oprofile_add_trace(unsigned long pc)
 {
-	struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(op_cpu_buffer);
+	struct oprofile_cpu_buffer *cpu_buf = this_cpu_ptr(&op_cpu_buffer);
 
 	if (!cpu_buf->tracing)
 		return;
Index: linux/drivers/oprofile/timer_int.c
===================================================================
--- linux.orig/drivers/oprofile/timer_int.c	2013-08-27 14:36:45.000000000 -0500
+++ linux/drivers/oprofile/timer_int.c	2013-08-27 14:37:04.284928047 -0500
@@ -32,7 +32,7 @@ static enum hrtimer_restart oprofile_hrt
 
 static void __oprofile_hrtimer_start(void *unused)
 {
-	struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
+	struct hrtimer *hrtimer = this_cpu_ptr(&oprofile_hrtimer);
 
 	if (!ctr_running)
 		return;

[gcv v3 32/35] arc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/arc/kernel/kprobes.c
===================================================================
--- linux.orig/arch/arc/kernel/kprobes.c	2013-08-26 13:28:53.000000000 -0500
+++ linux/arch/arc/kernel/kprobes.c	2013-08-26 13:29:19.285103021 -0500
@@ -87,13 +87,13 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }
 
 static inline void __kprobes set_current_kprobe(struct kprobe *p)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 static void __kprobes resume_execution(struct kprobe *p, unsigned long addr,
@@ -237,7 +237,7 @@ int __kprobes arc_kprobe_handler(unsigne
 
 		return 1;
 	} else if (kprobe_running()) {
-		p = __get_cpu_var(current_kprobe);
+		p = __this_cpu_read(current_kprobe);
 		if (p->break_handler && p->break_handler(p, regs)) {
 			setup_singlestep(p, regs);
 			kcb->kprobe_status = KPROBE_HIT_SS;
Index: linux/arch/arc/kernel/time.c
===================================================================
--- linux.orig/arch/arc/kernel/time.c	2013-08-26 13:28:53.000000000 -0500
+++ linux/arch/arc/kernel/time.c	2013-08-26 13:29:19.285103021 -0500
@@ -206,7 +206,7 @@ static DEFINE_PER_CPU(struct clock_event
 
 static irqreturn_t timer_irq_handler(int irq, void *dev_id)
 {
-	struct clock_event_device *clk = &__get_cpu_var(arc_clockevent_device);
+	struct clock_event_device *clk = this_cpu_ptr(&arc_clockevent_device);
 
 	arc_timer_event_ack(clk->mode == CLOCK_EVT_MODE_PERIODIC);
 	clk->event_handler(clk);

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Vineet Gupta]

On 08/29/2013 01:18 AM, Christoph Lameter wrote:
> Acked-by: Vineet Gupta <vgupta@synopsys.com>
> Signed-off-by: Christoph Lameter <cl@linux.com>

Applied to for-next.

Thx,
-Vineet

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 29 Aug 2013, Vineet Gupta wrote:

> On 08/29/2013 01:18 AM, Christoph Lameter wrote:
> > Acked-by: Vineet Gupta <vgupta@synopsys.com>
> > Signed-off-by: Christoph Lameter <cl@linux.com>
>
> Applied to for-next.

Ok dropping it from patchset.

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Vineet Gupta]

Hi Christoph,

On 08/29/2013 10:13 PM, Christoph Lameter wrote:
> On Thu, 29 Aug 2013, Vineet Gupta wrote:
> 
>> On 08/29/2013 01:18 AM, Christoph Lameter wrote:
>>> Acked-by: Vineet Gupta <vgupta@synopsys.com>
>>> Signed-off-by: Christoph Lameter <cl@linux.com>
>>
>> Applied to for-next.
> 
> Ok dropping it from patchset.
> 

Considering other discussions on this thread, shall I drop this from my for-curr
for this merge window ? I don't see any other arch changes to that effect in
latest linux-next.

-Vineet

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 4 Sep 2013, Vineet Gupta wrote:

> Considering other discussions on this thread, shall I drop this from my for-curr
> for this merge window ? I don't see any other arch changes to that effect in
> latest linux-next.

The required fix of the macros was merged yesterday into upstream.

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Vineet Gupta]

On 09/04/2013 07:44 PM, Christoph Lameter wrote:
> On Wed, 4 Sep 2013, Vineet Gupta wrote:
> 
>> Considering other discussions on this thread, shall I drop this from my for-curr
>> for this merge window ? I don't see any other arch changes to that effect in
>> latest linux-next.
> 
> The required fix of the macros was merged yesterday into upstream.
> 

Yes I do see the macro fix in mainline but no discussions related to missing
preemption debug checks after NAK from Peter/Ingo.

I'm gonna move this one out of my 3.12 merge window queue to my for-next - so not
dropping it (you can rest assured) but it doesn't look merge ready too. OK ?

-Vineet

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 5 Sep 2013, Vineet Gupta wrote:

> Yes I do see the macro fix in mainline but no discussions related to missing
> preemption debug checks after NAK from Peter/Ingo.

v4 was posted yesterday with the preemption bug checks.

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Vineet Gupta]

On 09/05/2013 07:49 PM, Christoph Lameter wrote:
> On Thu, 5 Sep 2013, Vineet Gupta wrote:
>
>> Yes I do see the macro fix in mainline but no discussions related to missing
>> preemption debug checks after NAK from Peter/Ingo.
> v4 was posted yesterday with the preemption bug checks.

I see that. IMHO it would be better if all of this gets merged into mainline in
one cycle.
I'm a relatively new maintainer so I'm not sure how to handle this. Andrew, Tejun,
Steven what say you ?

-Vineet

Re: [gcv v3 32/35] arc: Replace __get_cpu_var uses

[Vineet Gupta]

On 09/05/2013 07:49 PM, Christoph Lameter wrote:
> On Thu, 5 Sep 2013, Vineet Gupta wrote:
>
>> Yes I do see the macro fix in mainline but no discussions related to missing
>> preemption debug checks after NAK from Peter/Ingo.
> v4 was posted yesterday with the preemption bug checks.

I see that. IMHO it would be better if all of this gets merged into mainline in
one cycle.
I'm a relatively new maintainer so I'm not sure how to handle this. Andrew, Tejun,
Steven what say you ?

-Vineet

[gcv v3 28/35] blackfin: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)





Index: linux/arch/blackfin/include/asm/ipipe.h
===================================================================
--- linux.orig/arch/blackfin/include/asm/ipipe.h	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/include/asm/ipipe.h	2013-08-26 13:26:23.578979325 -0500
@@ -157,7 +157,7 @@ static inline unsigned long __ipipe_ffnz
 }
 
 #define __ipipe_do_root_xirq(ipd, irq)					\
-	((ipd)->irqs[irq].handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs)))
+	((ipd)->irqs[irq].handler(irq, __this_cpu_ptr(&__ipipe_tick_regs)))
 
 #define __ipipe_run_irqtail(irq)  /* Must be a macro */			\
 	do {								\
Index: linux/arch/blackfin/kernel/perf_event.c
===================================================================
--- linux.orig/arch/blackfin/kernel/perf_event.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/kernel/perf_event.c	2013-08-26 13:26:23.578979325 -0500
@@ -300,7 +300,7 @@ again:
 
 static void bfin_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -318,7 +318,7 @@ static void bfin_pmu_stop(struct perf_ev
 
 static void bfin_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -335,7 +335,7 @@ static void bfin_pmu_start(struct perf_e
 
 static void bfin_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	bfin_pmu_stop(event, PERF_EF_UPDATE);
 	__clear_bit(event->hw.idx, cpuc->used_mask);
@@ -345,7 +345,7 @@ static void bfin_pmu_del(struct perf_eve
 
 static int bfin_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 	int ret = -EAGAIN;
@@ -429,7 +429,7 @@ static int bfin_pmu_event_init(struct pe
 
 static void bfin_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	struct hw_perf_event *hwc;
 	int i;
Index: linux/arch/blackfin/mach-common/ints-priority.c
===================================================================
--- linux.orig/arch/blackfin/mach-common/ints-priority.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/mach-common/ints-priority.c	2013-08-26 13:26:23.578979325 -0500
@@ -1675,12 +1675,12 @@ asmlinkage int __ipipe_grab_irq(int vec,
 		bfin_write_TIMER_STATUS(1); /* Latch TIMIL0 */
 #endif
 		/* This is basically what we need from the register frame. */
-		__raw_get_cpu_var(__ipipe_tick_regs).ipend = regs->ipend;
-		__raw_get_cpu_var(__ipipe_tick_regs).pc = regs->pc;
+		__this_cpu_write(__ipipe_tick_regs.ipend, regs->ipend);
+		__this_cpu_write(__ipipe_tick_regs.pc, regs->pc);
 		if (this_domain != ipipe_root_domain)
-			__raw_get_cpu_var(__ipipe_tick_regs).ipend &= ~0x10;
+			__this_cpu_and(__ipipe_tick_regs.ipend, ~0x10);
 		else
-			__raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10;
+			__this_cpu_or(__ipipe_tick_regs.ipend, 0x10);
 	}
 
 	/*
Index: linux/arch/blackfin/mach-common/smp.c
===================================================================
--- linux.orig/arch/blackfin/mach-common/smp.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/mach-common/smp.c	2013-08-26 13:26:23.578979325 -0500
@@ -146,7 +146,7 @@ static irqreturn_t ipi_handler_int1(int
 
 	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
 
-	bfin_ipi_data = &__get_cpu_var(bfin_ipi);
+	bfin_ipi_data = this_cpu_ptr(&bfin_ipi);
 	while ((pending = atomic_xchg(&bfin_ipi_data->bits, 0)) != 0) {
 		msg = 0;
 		do {

[gcv v3 28/35] blackfin: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)





Index: linux/arch/blackfin/include/asm/ipipe.h
===================================================================
--- linux.orig/arch/blackfin/include/asm/ipipe.h	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/include/asm/ipipe.h	2013-08-26 13:26:23.578979325 -0500
@@ -157,7 +157,7 @@ static inline unsigned long __ipipe_ffnz
 }
 
 #define __ipipe_do_root_xirq(ipd, irq)					\
-	((ipd)->irqs[irq].handler(irq, &__raw_get_cpu_var(__ipipe_tick_regs)))
+	((ipd)->irqs[irq].handler(irq, __this_cpu_ptr(&__ipipe_tick_regs)))
 
 #define __ipipe_run_irqtail(irq)  /* Must be a macro */			\
 	do {								\
Index: linux/arch/blackfin/kernel/perf_event.c
===================================================================
--- linux.orig/arch/blackfin/kernel/perf_event.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/kernel/perf_event.c	2013-08-26 13:26:23.578979325 -0500
@@ -300,7 +300,7 @@ again:
 
 static void bfin_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -318,7 +318,7 @@ static void bfin_pmu_stop(struct perf_ev
 
 static void bfin_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -335,7 +335,7 @@ static void bfin_pmu_start(struct perf_e
 
 static void bfin_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	bfin_pmu_stop(event, PERF_EF_UPDATE);
 	__clear_bit(event->hw.idx, cpuc->used_mask);
@@ -345,7 +345,7 @@ static void bfin_pmu_del(struct perf_eve
 
 static int bfin_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 	int ret = -EAGAIN;
@@ -429,7 +429,7 @@ static int bfin_pmu_event_init(struct pe
 
 static void bfin_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	struct hw_perf_event *hwc;
 	int i;
Index: linux/arch/blackfin/mach-common/ints-priority.c
===================================================================
--- linux.orig/arch/blackfin/mach-common/ints-priority.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/mach-common/ints-priority.c	2013-08-26 13:26:23.578979325 -0500
@@ -1675,12 +1675,12 @@ asmlinkage int __ipipe_grab_irq(int vec,
 		bfin_write_TIMER_STATUS(1); /* Latch TIMIL0 */
 #endif
 		/* This is basically what we need from the register frame. */
-		__raw_get_cpu_var(__ipipe_tick_regs).ipend = regs->ipend;
-		__raw_get_cpu_var(__ipipe_tick_regs).pc = regs->pc;
+		__this_cpu_write(__ipipe_tick_regs.ipend, regs->ipend);
+		__this_cpu_write(__ipipe_tick_regs.pc, regs->pc);
 		if (this_domain != ipipe_root_domain)
-			__raw_get_cpu_var(__ipipe_tick_regs).ipend &= ~0x10;
+			__this_cpu_and(__ipipe_tick_regs.ipend, ~0x10);
 		else
-			__raw_get_cpu_var(__ipipe_tick_regs).ipend |= 0x10;
+			__this_cpu_or(__ipipe_tick_regs.ipend, 0x10);
 	}
 
 	/*
Index: linux/arch/blackfin/mach-common/smp.c
===================================================================
--- linux.orig/arch/blackfin/mach-common/smp.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/blackfin/mach-common/smp.c	2013-08-26 13:26:23.578979325 -0500
@@ -146,7 +146,7 @@ static irqreturn_t ipi_handler_int1(int
 
 	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
 
-	bfin_ipi_data = &__get_cpu_var(bfin_ipi);
+	bfin_ipi_data = this_cpu_ptr(&bfin_ipi);
 	while ((pending = atomic_xchg(&bfin_ipi_data->bits, 0)) != 0) {
 		msg = 0;
 		do {

[gcv v3 07/35] mm: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/lib/radix-tree.c
===================================================================
--- linux.orig/lib/radix-tree.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/lib/radix-tree.c	2013-08-26 14:25:30.709616290 -0500
@@ -215,7 +215,7 @@ radix_tree_node_alloc(struct radix_tree_
 		 * succeed in getting a node here (and never reach
 		 * kmem_cache_alloc)
 		 */
-		rtp = &__get_cpu_var(radix_tree_preloads);
+		rtp = this_cpu_ptr(&radix_tree_preloads);
 		if (rtp->nr) {
 			ret = rtp->nodes[rtp->nr - 1];
 			rtp->nodes[rtp->nr - 1] = NULL;
@@ -271,14 +271,14 @@ int radix_tree_preload(gfp_t gfp_mask)
 	int ret = -ENOMEM;
 
 	preempt_disable();
-	rtp = &__get_cpu_var(radix_tree_preloads);
+	rtp = this_cpu_ptr(&radix_tree_preloads);
 	while (rtp->nr < ARRAY_SIZE(rtp->nodes)) {
 		preempt_enable();
 		node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
 		if (node == NULL)
 			goto out;
 		preempt_disable();
-		rtp = &__get_cpu_var(radix_tree_preloads);
+		rtp = this_cpu_ptr(&radix_tree_preloads);
 		if (rtp->nr < ARRAY_SIZE(rtp->nodes))
 			rtp->nodes[rtp->nr++] = node;
 		else
Index: linux/mm/memcontrol.c
===================================================================
--- linux.orig/mm/memcontrol.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/memcontrol.c	2013-08-26 14:25:30.713616248 -0500
@@ -2398,7 +2398,7 @@ static void drain_stock(struct memcg_sto
  */
 static void drain_local_stock(struct work_struct *dummy)
 {
-	struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
+	struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock);
 	drain_stock(stock);
 	clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
 }
Index: linux/mm/memory-failure.c
===================================================================
--- linux.orig/mm/memory-failure.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/memory-failure.c	2013-08-26 14:25:30.713616248 -0500
@@ -1279,7 +1279,7 @@ static void memory_failure_work_func(str
 	unsigned long proc_flags;
 	int gotten;
 
-	mf_cpu = &__get_cpu_var(memory_failure_cpu);
+	mf_cpu = this_cpu_ptr(&memory_failure_cpu);
 	for (;;) {
 		spin_lock_irqsave(&mf_cpu->lock, proc_flags);
 		gotten = kfifo_get(&mf_cpu->fifo, &entry);
Index: linux/mm/page-writeback.c
===================================================================
--- linux.orig/mm/page-writeback.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/page-writeback.c	2013-08-26 14:25:30.713616248 -0500
@@ -1487,7 +1487,7 @@ void balance_dirty_pages_ratelimited(str
 	 * 1000+ tasks, all of them start dirtying pages at exactly the same
 	 * time, hence all honoured too large initial task->nr_dirtied_pause.
 	 */
-	p =  &__get_cpu_var(bdp_ratelimits);
+	p =  this_cpu_ptr(&bdp_ratelimits);
 	if (unlikely(current->nr_dirtied >= ratelimit))
 		*p = 0;
 	else if (unlikely(*p >= ratelimit_pages)) {
@@ -1499,7 +1499,7 @@ void balance_dirty_pages_ratelimited(str
 	 * short-lived tasks (eg. gcc invocations in a kernel build) escaping
 	 * the dirty throttling and livelock other long-run dirtiers.
 	 */
-	p = &__get_cpu_var(dirty_throttle_leaks);
+	p = this_cpu_ptr(&dirty_throttle_leaks);
 	if (*p > 0 && current->nr_dirtied < ratelimit) {
 		unsigned long nr_pages_dirtied;
 		nr_pages_dirtied = min(*p, ratelimit - current->nr_dirtied);
Index: linux/mm/swap.c
===================================================================
--- linux.orig/mm/swap.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/swap.c	2013-08-26 14:25:30.717616206 -0500
@@ -359,7 +359,7 @@ void rotate_reclaimable_page(struct page
 
 		page_cache_get(page);
 		local_irq_save(flags);
-		pvec = &__get_cpu_var(lru_rotate_pvecs);
+		pvec = this_cpu_ptr(&lru_rotate_pvecs);
 		if (!pagevec_add(pvec, page))
 			pagevec_move_tail(pvec);
 		local_irq_restore(flags);
Index: linux/mm/vmalloc.c
===================================================================
--- linux.orig/mm/vmalloc.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/vmalloc.c	2013-08-26 14:25:30.717616206 -0500
@@ -1487,7 +1487,7 @@ void vfree(const void *addr)
 	if (!addr)
 		return;
 	if (unlikely(in_interrupt())) {
-		struct vfree_deferred *p = &__get_cpu_var(vfree_deferred);
+		struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
 		if (llist_add((struct llist_node *)addr, &p->list))
 			schedule_work(&p->wq);
 	} else
Index: linux/mm/vmstat.c
===================================================================
--- linux.orig/mm/vmstat.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/vmstat.c	2013-08-26 14:25:30.717616206 -0500
@@ -1178,7 +1178,7 @@ int sysctl_stat_interval __read_mostly =
 static void vmstat_update(struct work_struct *w)
 {
 	refresh_cpu_vm_stats(smp_processor_id());
-	schedule_delayed_work(&__get_cpu_var(vmstat_work),
+	schedule_delayed_work(this_cpu_ptr(&vmstat_work),
 		round_jiffies_relative(sysctl_stat_interval));
 }
 

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[gcv v3 07/35] mm: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/lib/radix-tree.c
===================================================================
--- linux.orig/lib/radix-tree.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/lib/radix-tree.c	2013-08-26 14:25:30.709616290 -0500
@@ -215,7 +215,7 @@ radix_tree_node_alloc(struct radix_tree_
 		 * succeed in getting a node here (and never reach
 		 * kmem_cache_alloc)
 		 */
-		rtp = &__get_cpu_var(radix_tree_preloads);
+		rtp = this_cpu_ptr(&radix_tree_preloads);
 		if (rtp->nr) {
 			ret = rtp->nodes[rtp->nr - 1];
 			rtp->nodes[rtp->nr - 1] = NULL;
@@ -271,14 +271,14 @@ int radix_tree_preload(gfp_t gfp_mask)
 	int ret = -ENOMEM;
 
 	preempt_disable();
-	rtp = &__get_cpu_var(radix_tree_preloads);
+	rtp = this_cpu_ptr(&radix_tree_preloads);
 	while (rtp->nr < ARRAY_SIZE(rtp->nodes)) {
 		preempt_enable();
 		node = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
 		if (node == NULL)
 			goto out;
 		preempt_disable();
-		rtp = &__get_cpu_var(radix_tree_preloads);
+		rtp = this_cpu_ptr(&radix_tree_preloads);
 		if (rtp->nr < ARRAY_SIZE(rtp->nodes))
 			rtp->nodes[rtp->nr++] = node;
 		else
Index: linux/mm/memcontrol.c
===================================================================
--- linux.orig/mm/memcontrol.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/memcontrol.c	2013-08-26 14:25:30.713616248 -0500
@@ -2398,7 +2398,7 @@ static void drain_stock(struct memcg_sto
  */
 static void drain_local_stock(struct work_struct *dummy)
 {
-	struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
+	struct memcg_stock_pcp *stock = this_cpu_ptr(&memcg_stock);
 	drain_stock(stock);
 	clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
 }
Index: linux/mm/memory-failure.c
===================================================================
--- linux.orig/mm/memory-failure.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/memory-failure.c	2013-08-26 14:25:30.713616248 -0500
@@ -1279,7 +1279,7 @@ static void memory_failure_work_func(str
 	unsigned long proc_flags;
 	int gotten;
 
-	mf_cpu = &__get_cpu_var(memory_failure_cpu);
+	mf_cpu = this_cpu_ptr(&memory_failure_cpu);
 	for (;;) {
 		spin_lock_irqsave(&mf_cpu->lock, proc_flags);
 		gotten = kfifo_get(&mf_cpu->fifo, &entry);
Index: linux/mm/page-writeback.c
===================================================================
--- linux.orig/mm/page-writeback.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/page-writeback.c	2013-08-26 14:25:30.713616248 -0500
@@ -1487,7 +1487,7 @@ void balance_dirty_pages_ratelimited(str
 	 * 1000+ tasks, all of them start dirtying pages at exactly the same
 	 * time, hence all honoured too large initial task->nr_dirtied_pause.
 	 */
-	p =  &__get_cpu_var(bdp_ratelimits);
+	p =  this_cpu_ptr(&bdp_ratelimits);
 	if (unlikely(current->nr_dirtied >= ratelimit))
 		*p = 0;
 	else if (unlikely(*p >= ratelimit_pages)) {
@@ -1499,7 +1499,7 @@ void balance_dirty_pages_ratelimited(str
 	 * short-lived tasks (eg. gcc invocations in a kernel build) escaping
 	 * the dirty throttling and livelock other long-run dirtiers.
 	 */
-	p = &__get_cpu_var(dirty_throttle_leaks);
+	p = this_cpu_ptr(&dirty_throttle_leaks);
 	if (*p > 0 && current->nr_dirtied < ratelimit) {
 		unsigned long nr_pages_dirtied;
 		nr_pages_dirtied = min(*p, ratelimit - current->nr_dirtied);
Index: linux/mm/swap.c
===================================================================
--- linux.orig/mm/swap.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/swap.c	2013-08-26 14:25:30.717616206 -0500
@@ -359,7 +359,7 @@ void rotate_reclaimable_page(struct page
 
 		page_cache_get(page);
 		local_irq_save(flags);
-		pvec = &__get_cpu_var(lru_rotate_pvecs);
+		pvec = this_cpu_ptr(&lru_rotate_pvecs);
 		if (!pagevec_add(pvec, page))
 			pagevec_move_tail(pvec);
 		local_irq_restore(flags);
Index: linux/mm/vmalloc.c
===================================================================
--- linux.orig/mm/vmalloc.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/vmalloc.c	2013-08-26 14:25:30.717616206 -0500
@@ -1487,7 +1487,7 @@ void vfree(const void *addr)
 	if (!addr)
 		return;
 	if (unlikely(in_interrupt())) {
-		struct vfree_deferred *p = &__get_cpu_var(vfree_deferred);
+		struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
 		if (llist_add((struct llist_node *)addr, &p->list))
 			schedule_work(&p->wq);
 	} else
Index: linux/mm/vmstat.c
===================================================================
--- linux.orig/mm/vmstat.c	2013-08-26 14:24:48.000000000 -0500
+++ linux/mm/vmstat.c	2013-08-26 14:25:30.717616206 -0500
@@ -1178,7 +1178,7 @@ int sysctl_stat_interval __read_mostly =
 static void vmstat_update(struct work_struct *w)
 {
 	refresh_cpu_vm_stats(smp_processor_id());
-	schedule_delayed_work(&__get_cpu_var(vmstat_work),
+	schedule_delayed_work(this_cpu_ptr(&vmstat_work),
 		round_jiffies_relative(sysctl_stat_interval));
 }
 

[gcv v3 19/35] drivers: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/clocksource/metag_generic.c
===================================================================
--- linux.orig/drivers/clocksource/metag_generic.c	2013-08-27 14:47:06.602928492 -0500
+++ linux/drivers/clocksource/metag_generic.c	2013-08-27 14:47:06.594928572 -0500
@@ -90,7 +90,7 @@ static struct clocksource clocksource_me
 
 static irqreturn_t metag_timer_interrupt(int irq, void *dummy)
 {
-	struct clock_event_device *evt = &__get_cpu_var(local_clockevent);
+	struct clock_event_device *evt = this_cpu_ptr(&local_clockevent);
 
 	evt->event_handler(evt);
 

[gcv v3 19/35] drivers: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/clocksource/metag_generic.c
===================================================================
--- linux.orig/drivers/clocksource/metag_generic.c	2013-08-27 14:47:06.602928492 -0500
+++ linux/drivers/clocksource/metag_generic.c	2013-08-27 14:47:06.594928572 -0500
@@ -90,7 +90,7 @@ static struct clocksource clocksource_me
 
 static irqreturn_t metag_timer_interrupt(int irq, void *dummy)
 {
-	struct clock_event_device *evt = &__get_cpu_var(local_clockevent);
+	struct clock_event_device *evt = this_cpu_ptr(&local_clockevent);
 
 	evt->event_handler(evt);
 

Re: [gcv v3 19/35] drivers: Replace __get_cpu_var uses

[James Hogan]

On 28/08/13 20:48, Christoph Lameter wrote:
> Signed-off-by: Christoph Lameter <cl@linux.com>

Acked-by: James Hogan <james.hogan@imgtec.com>

Let me know if you want me to take this metag_generic.c and the
arch/metag one through the metag tree.

Cheers
James

[gcv v3 25/35] powerpc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/powerpc/include/asm/cputime.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/cputime.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/cputime.h	2013-08-28 14:15:09.943099694 -0500
@@ -56,10 +56,10 @@ static inline unsigned long cputime_to_j
 static inline cputime_t cputime_to_scaled(const cputime_t ct)
 {
 	if (cpu_has_feature(CPU_FTR_SPURR) &&
-	    __get_cpu_var(cputime_last_delta))
+	    __this_cpu_read(cputime_last_delta))
 		return (__force u64) ct *
-			__get_cpu_var(cputime_scaled_last_delta) /
-			__get_cpu_var(cputime_last_delta);
+			__this_cpu_read(cputime_scaled_last_delta) /
+			__this_cpu_read(cputime_last_delta);
 	return ct;
 }
 
Index: linux/arch/powerpc/include/asm/hardirq.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/hardirq.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/hardirq.h	2013-08-28 14:15:09.943099694 -0500
@@ -19,7 +19,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpust
 
 #define __ARCH_IRQ_STAT
 
-#define local_softirq_pending()	__get_cpu_var(irq_stat).__softirq_pending
+#define local_softirq_pending()	__this_cpu_read(irq_stat.__softirq_pending)
 
 static inline void ack_bad_irq(unsigned int irq)
 {
Index: linux/arch/powerpc/include/asm/tlbflush.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/tlbflush.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/tlbflush.h	2013-08-28 14:15:09.943099694 -0500
@@ -107,14 +107,14 @@ extern void __flush_tlb_pending(struct p
 
 static inline void arch_enter_lazy_mmu_mode(void)
 {
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 
 	batch->active = 1;
 }
 
 static inline void arch_leave_lazy_mmu_mode(void)
 {
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 
 	if (batch->index)
 		__flush_tlb_pending(batch);
Index: linux/arch/powerpc/include/asm/xics.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/xics.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/xics.h	2013-08-28 14:15:09.943099694 -0500
@@ -97,7 +97,7 @@ DECLARE_PER_CPU(struct xics_cppr, xics_c
 
 static inline void xics_push_cppr(unsigned int vec)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	if (WARN_ON(os_cppr->index >= MAX_NUM_PRIORITIES - 1))
 		return;
@@ -110,7 +110,7 @@ static inline void xics_push_cppr(unsign
 
 static inline unsigned char xics_pop_cppr(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	if (WARN_ON(os_cppr->index < 1))
 		return LOWEST_PRIORITY;
@@ -120,7 +120,7 @@ static inline unsigned char xics_pop_cpp
 
 static inline void xics_set_base_cppr(unsigned char cppr)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	/* we only really want to set the priority when there's
 	 * just one cppr value on the stack
@@ -132,7 +132,7 @@ static inline void xics_set_base_cppr(un
 
 static inline unsigned char xics_cppr_top(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 	
 	return os_cppr->stack[os_cppr->index];
 }
Index: linux/arch/powerpc/kernel/dbell.c
===================================================================
--- linux.orig/arch/powerpc/kernel/dbell.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/dbell.c	2013-08-28 14:15:09.943099694 -0500
@@ -41,7 +41,7 @@ void doorbell_exception(struct pt_regs *
 
 	may_hard_irq_enable();
 
-	__get_cpu_var(irq_stat).doorbell_irqs++;
+	__this_cpu_inc(irq_stat.doorbell_irqs);
 
 	smp_ipi_demux();
 
Index: linux/arch/powerpc/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/powerpc/kernel/hw_breakpoint.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/hw_breakpoint.c	2013-08-28 14:15:09.943099694 -0500
@@ -64,7 +64,7 @@ int hw_breakpoint_slots(int type)
 int arch_install_hw_breakpoint(struct perf_event *bp)
 {
 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-	struct perf_event **slot = &__get_cpu_var(bp_per_reg);
+	struct perf_event **slot = this_cpu_ptr(&bp_per_reg);
 
 	*slot = bp;
 
@@ -89,7 +89,7 @@ int arch_install_hw_breakpoint(struct pe
  */
 void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 {
-	struct perf_event **slot = &__get_cpu_var(bp_per_reg);
+	struct perf_event **slot = this_cpu_ptr(&bp_per_reg);
 
 	if (*slot != bp) {
 		WARN_ONCE(1, "Can't find the breakpoint");
@@ -227,7 +227,7 @@ int __kprobes hw_breakpoint_handler(stru
 	 */
 	rcu_read_lock();
 
-	bp = __get_cpu_var(bp_per_reg);
+	bp = __this_cpu_read(bp_per_reg);
 	if (!bp)
 		goto out;
 	info = counter_arch_bp(bp);
Index: linux/arch/powerpc/kernel/irq.c
===================================================================
--- linux.orig/arch/powerpc/kernel/irq.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/irq.c	2013-08-28 14:15:55.854634913 -0500
@@ -114,7 +114,7 @@ static inline notrace void set_soft_enab
 static inline notrace int decrementer_check_overflow(void)
 {
  	u64 now = get_tb_or_rtc();
- 	u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
  
 	return now >= *next_tb;
 }
@@ -526,7 +526,7 @@ void do_IRQ(struct pt_regs *regs)
 	if (irq != NO_IRQ)
 		handle_one_irq(irq);
 	else
-		__get_cpu_var(irq_stat).spurious_irqs++;
+		__this_cpu_inc(irq_stat.spurious_irqs);
 
 	trace_irq_exit(regs);
 
Index: linux/arch/powerpc/kernel/kprobes.c
===================================================================
--- linux.orig/arch/powerpc/kernel/kprobes.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/kprobes.c	2013-08-28 14:15:09.947099653 -0500
@@ -118,7 +118,7 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_saved_msr = kcb->prev_kprobe.saved_msr;
 }
@@ -126,7 +126,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 				struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_saved_msr = regs->msr;
 }
 
@@ -191,7 +191,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
Index: linux/arch/powerpc/kernel/process.c
===================================================================
--- linux.orig/arch/powerpc/kernel/process.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/process.c	2013-08-28 14:15:09.947099653 -0500
@@ -453,7 +453,7 @@ static inline int set_dawr(struct arch_h
 
 int set_breakpoint(struct arch_hw_breakpoint *brk)
 {
-	__get_cpu_var(current_brk) = *brk;
+	__this_cpu_write(current_brk, *brk);
 
 	if (cpu_has_feature(CPU_FTR_DAWR))
 		return set_dawr(brk);
@@ -686,7 +686,7 @@ struct task_struct *__switch_to(struct t
  * schedule DABR
  */
 #ifndef CONFIG_HAVE_HW_BREAKPOINT
-	if (unlikely(hw_brk_match(&__get_cpu_var(current_brk), &new->thread.hw_brk)))
+	if (unlikely(hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
 		set_breakpoint(&new->thread.hw_brk);
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
@@ -700,7 +700,7 @@ struct task_struct *__switch_to(struct t
 	 * Collect processor utilization data per process
 	 */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
 		long unsigned start_tb, current_tb;
 		start_tb = old_thread->start_tb;
 		cu->current_tb = current_tb = mfspr(SPRN_PURR);
@@ -710,7 +710,7 @@ struct task_struct *__switch_to(struct t
 #endif /* CONFIG_PPC64 */
 
 #ifdef CONFIG_PPC_BOOK3S_64
-	batch = &__get_cpu_var(ppc64_tlb_batch);
+	batch = this_cpu_ptr(&ppc64_tlb_batch);
 	if (batch->active) {
 		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
 		if (batch->index)
@@ -735,7 +735,7 @@ struct task_struct *__switch_to(struct t
 #ifdef CONFIG_PPC_BOOK3S_64
 	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
 		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
-		batch = &__get_cpu_var(ppc64_tlb_batch);
+		batch = this_cpu_ptr(&ppc64_tlb_batch);
 		batch->active = 1;
 	}
 #endif /* CONFIG_PPC_BOOK3S_64 */
Index: linux/arch/powerpc/kernel/smp.c
===================================================================
--- linux.orig/arch/powerpc/kernel/smp.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/smp.c	2013-08-28 14:15:09.947099653 -0500
@@ -212,7 +212,7 @@ void smp_muxed_ipi_message_pass(int cpu,
 
 irqreturn_t smp_ipi_demux(void)
 {
-	struct cpu_messages *info = &__get_cpu_var(ipi_message);
+	struct cpu_messages *info = this_cpu_ptr(&ipi_message);
 	unsigned int all;
 
 	mb();	/* order any irq clear */
@@ -402,9 +402,9 @@ void generic_mach_cpu_die(void)
 	idle_task_exit();
 	cpu = smp_processor_id();
 	printk(KERN_DEBUG "CPU%d offline\n", cpu);
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 	smp_wmb();
-	while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
+	while (__this_cpu_read(cpu_state) != CPU_UP_PREPARE)
 		cpu_relax();
 }
 
Index: linux/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux.orig/arch/powerpc/kernel/sysfs.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/sysfs.c	2013-08-28 14:15:09.947099653 -0500
@@ -97,10 +97,10 @@ void ppc_enable_pmcs(void)
 	ppc_set_pmu_inuse(1);
 
 	/* Only need to enable them once */
-	if (__get_cpu_var(pmcs_enabled))
+	if (__this_cpu_read(pmcs_enabled))
 		return;
 
-	__get_cpu_var(pmcs_enabled) = 1;
+	__this_cpu_write(pmcs_enabled, 1);
 
 	if (ppc_md.enable_pmcs)
 		ppc_md.enable_pmcs();
Index: linux/arch/powerpc/kernel/time.c
===================================================================
--- linux.orig/arch/powerpc/kernel/time.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/time.c	2013-08-28 14:15:09.951099613 -0500
@@ -457,9 +457,9 @@ static inline void clear_irq_work_pendin
 
 DEFINE_PER_CPU(u8, irq_work_pending);
 
-#define set_irq_work_pending_flag()	__get_cpu_var(irq_work_pending) = 1
-#define test_irq_work_pending()		__get_cpu_var(irq_work_pending)
-#define clear_irq_work_pending()	__get_cpu_var(irq_work_pending) = 0
+#define set_irq_work_pending_flag()	__this_cpu_write(irq_work_pending, 1)
+#define test_irq_work_pending()		__this_cpu_read(irq_work_pending)
+#define clear_irq_work_pending()	__this_cpu_write(irq_work_pending, 0)
 
 #endif /* 32 vs 64 bit */
 
@@ -485,8 +485,8 @@ void arch_irq_work_raise(void)
 void timer_interrupt(struct pt_regs * regs)
 {
 	struct pt_regs *old_regs;
-	u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
-	struct clock_event_device *evt = &__get_cpu_var(decrementers);
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
+	struct clock_event_device *evt = this_cpu_ptr(&decrementers);
 	u64 now;
 
 	/* Ensure a positive value is written to the decrementer, or else
@@ -510,7 +510,7 @@ void timer_interrupt(struct pt_regs * re
 	 */
 	may_hard_irq_enable();
 
-	__get_cpu_var(irq_stat).timer_irqs++;
+	__this_cpu_inc(irq_stat.timer_irqs);
 
 #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
 	if (atomic_read(&ppc_n_lost_interrupts) != 0)
@@ -541,7 +541,7 @@ void timer_interrupt(struct pt_regs * re
 #ifdef CONFIG_PPC64
 	/* collect purr register values often, for accurate calculations */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
 		cu->current_tb = mfspr(SPRN_PURR);
 	}
 #endif
@@ -801,7 +801,7 @@ static void __init clocksource_init(void
 static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev)
 {
-	__get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;
+	__this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
 	set_dec(evt);
 	return 0;
 }
Index: linux/arch/powerpc/kernel/traps.c
===================================================================
--- linux.orig/arch/powerpc/kernel/traps.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/traps.c	2013-08-28 14:15:09.951099613 -0500
@@ -670,7 +670,7 @@ void machine_check_exception(struct pt_r
 	enum ctx_state prev_state = exception_enter();
 	int recover = 0;
 
-	__get_cpu_var(irq_stat).mce_exceptions++;
+	__this_cpu_inc(irq_stat.mce_exceptions);
 
 	/* See if any machine dependent calls. In theory, we would want
 	 * to call the CPU first, and call the ppc_md. one if the CPU
@@ -1436,7 +1436,7 @@ void vsx_unavailable_tm(struct pt_regs *
 
 void performance_monitor_exception(struct pt_regs *regs)
 {
-	__get_cpu_var(irq_stat).pmu_irqs++;
+	__this_cpu_inc(irq_stat.pmu_irqs);
 
 	perf_irq(regs);
 }
Index: linux/arch/powerpc/kvm/e500.c
===================================================================
--- linux.orig/arch/powerpc/kvm/e500.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kvm/e500.c	2013-08-28 14:15:09.951099613 -0500
@@ -74,11 +74,11 @@ static inline int local_sid_setup_one(st
 	unsigned long sid;
 	int ret = -1;
 
-	sid = ++(__get_cpu_var(pcpu_last_used_sid));
+	sid = __this_cpu_inc_return(pcpu_last_used_sid);
 	if (sid < NUM_TIDS) {
-		__get_cpu_var(pcpu_sids).entry[sid] = entry;
+		__this_cpu_write(pcpu_sids)entry[sid], entry);
 		entry->val = sid;
-		entry->pentry = &__get_cpu_var(pcpu_sids).entry[sid];
+		entry->pentry = this_cpu_ptr(&pcpu_sids.entry[sid]);
 		ret = sid;
 	}
 
@@ -106,8 +106,8 @@ static inline int local_sid_setup_one(st
 static inline int local_sid_lookup(struct id *entry)
 {
 	if (entry && entry->val != 0 &&
-	    __get_cpu_var(pcpu_sids).entry[entry->val] == entry &&
-	    entry->pentry == &__get_cpu_var(pcpu_sids).entry[entry->val])
+	    __this_cpu_read(pcpu_sids.entry[entry->val]) == entry &&
+	    entry->pentry == this_cpu_ptr(&pcpu_sids.entry[entry->val]))
 		return entry->val;
 	return -1;
 }
@@ -115,8 +115,8 @@ static inline int local_sid_lookup(struc
 /* Invalidate all id mappings on local core -- call with preempt disabled */
 static inline void local_sid_destroy_all(void)
 {
-	__get_cpu_var(pcpu_last_used_sid) = 0;
-	memset(&__get_cpu_var(pcpu_sids), 0, sizeof(__get_cpu_var(pcpu_sids)));
+	__this_cpu_write(pcpu_last_used_sid, 0);
+	memset(this_cpu_ptr(&pcpu_sids), 0, sizeof(pcpu_sids));
 }
 
 static void *kvmppc_e500_id_table_alloc(struct kvmppc_vcpu_e500 *vcpu_e500)
Index: linux/arch/powerpc/kvm/e500mc.c
===================================================================
--- linux.orig/arch/powerpc/kvm/e500mc.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kvm/e500mc.c	2013-08-28 14:15:09.951099613 -0500
@@ -139,9 +139,9 @@ void kvmppc_core_vcpu_load(struct kvm_vc
 	mtspr(SPRN_GESR, vcpu->arch.shared->esr);
 
 	if (vcpu->arch.oldpir != mfspr(SPRN_PIR) ||
-	    __get_cpu_var(last_vcpu_on_cpu) != vcpu) {
+	    __this_cpu_read(last_vcpu_on_cpu) != vcpu) {
 		kvmppc_e500_tlbil_all(vcpu_e500);
-		__get_cpu_var(last_vcpu_on_cpu) = vcpu;
+		__this_cpu_read(last_vcpu_on_cpu) = vcpu;
 	}
 
 	kvmppc_load_guest_fp(vcpu);
Index: linux/arch/powerpc/mm/hash_native_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/hash_native_64.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hash_native_64.c	2013-08-28 14:15:09.951099613 -0500
@@ -643,7 +643,7 @@ static void native_flush_hash_range(unsi
 	unsigned long want_v;
 	unsigned long flags;
 	real_pte_t pte;
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 	unsigned long psize = batch->psize;
 	int ssize = batch->ssize;
 	int i;
Index: linux/arch/powerpc/mm/hash_utils_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/hash_utils_64.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hash_utils_64.c	2013-08-28 14:15:09.955099572 -0500
@@ -1285,7 +1285,7 @@ void flush_hash_range(unsigned long numb
 	else {
 		int i;
 		struct ppc64_tlb_batch *batch =
-			&__get_cpu_var(ppc64_tlb_batch);
+			this_cpu_ptr(&ppc64_tlb_batch);
 
 		for (i = 0; i < number; i++)
 			flush_hash_page(batch->vpn[i], batch->pte[i],
Index: linux/arch/powerpc/mm/hugetlbpage-book3e.c
===================================================================
--- linux.orig/arch/powerpc/mm/hugetlbpage-book3e.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hugetlbpage-book3e.c	2013-08-28 14:15:09.955099572 -0500
@@ -80,14 +80,14 @@ void book3e_hugetlb_preload(struct vm_ar
 	ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
 
 	/* We have to use the CAM(TLB1) on FSL parts for hugepages */
-	index = __get_cpu_var(next_tlbcam_idx);
+	index = __this_cpu_read(next_tlbcam_idx);
 	mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));
 
 	/* Just round-robin the entries and wrap when we hit the end */
 	if (unlikely(index == ncams - 1))
-		__get_cpu_var(next_tlbcam_idx) = tlbcam_index;
+		__this_cpu_write(next_tlbcam_idx, tlbcam_index);
 	else
-		__get_cpu_var(next_tlbcam_idx)++;
+		__this_cpu_inc(next_tlbcam_idx);
 #endif
 	mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
 	mas2 = ea & ~((1UL << shift) - 1);
Index: linux/arch/powerpc/mm/hugetlbpage.c
===================================================================
--- linux.orig/arch/powerpc/mm/hugetlbpage.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hugetlbpage.c	2013-08-28 14:15:09.955099572 -0500
@@ -462,7 +462,7 @@ static void hugepd_free(struct mmu_gathe
 {
 	struct hugepd_freelist **batchp;
 
-	batchp = &__get_cpu_var(hugepd_freelist_cur);
+	batchp = this_cpu_ptr(&hugepd_freelist_cur);
 
 	if (atomic_read(&tlb->mm->mm_users) < 2 ||
 	    cpumask_equal(mm_cpumask(tlb->mm),
Index: linux/arch/powerpc/mm/stab.c
===================================================================
--- linux.orig/arch/powerpc/mm/stab.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/stab.c	2013-08-28 14:15:09.955099572 -0500
@@ -133,12 +133,12 @@ static int __ste_allocate(unsigned long
 	stab_entry = make_ste(get_paca()->stab_addr, GET_ESID(ea), vsid);
 
 	if (!is_kernel_addr(ea)) {
-		offset = __get_cpu_var(stab_cache_ptr);
+		offset = __this_cpu_read(stab_cache_ptr);
 		if (offset < NR_STAB_CACHE_ENTRIES)
-			__get_cpu_var(stab_cache[offset++]) = stab_entry;
+			__this_cpu_read(stab_cache[offset++]) = stab_entry;
 		else
 			offset = NR_STAB_CACHE_ENTRIES+1;
-		__get_cpu_var(stab_cache_ptr) = offset;
+		__this_cpu_write(stab_cache_ptr, offset);
 
 		/* Order update */
 		asm volatile("sync":::"memory");
@@ -177,12 +177,12 @@ void switch_stab(struct task_struct *tsk
 	 */
 	hard_irq_disable();
 
-	offset = __get_cpu_var(stab_cache_ptr);
+	offset = __this_cpu_read(stab_cache_ptr);
 	if (offset <= NR_STAB_CACHE_ENTRIES) {
 		int i;
 
 		for (i = 0; i < offset; i++) {
-			ste = stab + __get_cpu_var(stab_cache[i]);
+			ste = stab + __this_cpu_read(stab_cache[i]);
 			ste->esid_data = 0; /* invalidate entry */
 		}
 	} else {
@@ -206,7 +206,7 @@ void switch_stab(struct task_struct *tsk
 
 	asm volatile("sync; slbia; sync":::"memory");
 
-	__get_cpu_var(stab_cache_ptr) = 0;
+	__this_cpu_write(stab_cache_ptr, 0);
 
 	/* Now preload some entries for the new task */
 	if (test_tsk_thread_flag(tsk, TIF_32BIT))
Index: linux/arch/powerpc/perf/core-book3s.c
===================================================================
--- linux.orig/arch/powerpc/perf/core-book3s.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/perf/core-book3s.c	2013-08-28 14:15:09.959099532 -0500
@@ -332,7 +332,7 @@ static void power_pmu_bhrb_reset(void)
 
 static void power_pmu_bhrb_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!ppmu->bhrb_nr)
 		return;
@@ -347,7 +347,7 @@ static void power_pmu_bhrb_enable(struct
 
 static void power_pmu_bhrb_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!ppmu->bhrb_nr)
 		return;
@@ -961,7 +961,7 @@ static void power_pmu_disable(struct pmu
 	if (!ppmu)
 		return;
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuhw->disabled) {
 		/*
@@ -1027,7 +1027,7 @@ static void power_pmu_enable(struct pmu
 		return;
 	local_irq_save(flags);
 
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	if (!cpuhw->disabled)
 		goto out;
 
@@ -1211,7 +1211,7 @@ static int power_pmu_add(struct perf_eve
 	 * Add the event to the list (if there is room)
 	 * and check whether the total set is still feasible.
 	 */
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	n0 = cpuhw->n_events;
 	if (n0 >= ppmu->n_counter)
 		goto out;
@@ -1277,7 +1277,7 @@ static void power_pmu_del(struct perf_ev
 
 	power_pmu_read(event);
 
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	for (i = 0; i < cpuhw->n_events; ++i) {
 		if (event == cpuhw->event[i]) {
 			while (++i < cpuhw->n_events) {
@@ -1383,7 +1383,7 @@ static void power_pmu_stop(struct perf_e
  */
 void power_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	perf_pmu_disable(pmu);
 	cpuhw->group_flag |= PERF_EVENT_TXN;
@@ -1397,7 +1397,7 @@ void power_pmu_start_txn(struct pmu *pmu
  */
 void power_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	cpuhw->group_flag &= ~PERF_EVENT_TXN;
 	perf_pmu_enable(pmu);
@@ -1415,7 +1415,7 @@ int power_pmu_commit_txn(struct pmu *pmu
 
 	if (!ppmu)
 		return -EAGAIN;
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	n = cpuhw->n_events;
 	if (check_excludes(cpuhw->event, cpuhw->flags, 0, n))
 		return -EAGAIN;
@@ -1772,7 +1772,7 @@ static void record_and_restart(struct pe
 
 		if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) {
 			struct cpu_hw_events *cpuhw;
-			cpuhw = &__get_cpu_var(cpu_hw_events);
+			cpuhw = this_cpu_ptr(&cpu_hw_events);
 			power_pmu_bhrb_read(cpuhw);
 			data.br_stack = &cpuhw->bhrb_stack;
 		}
@@ -1845,7 +1845,7 @@ static bool pmc_overflow(unsigned long v
 static void perf_event_interrupt(struct pt_regs *regs)
 {
 	int i, j;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val[8];
 	int found, active;
Index: linux/arch/powerpc/perf/core-fsl-emb.c
===================================================================
--- linux.orig/arch/powerpc/perf/core-fsl-emb.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/perf/core-fsl-emb.c	2013-08-28 14:15:09.959099532 -0500
@@ -186,7 +186,7 @@ static void fsl_emb_pmu_disable(struct p
 	unsigned long flags;
 
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuhw->disabled) {
 		cpuhw->disabled = 1;
@@ -225,7 +225,7 @@ static void fsl_emb_pmu_enable(struct pm
 	unsigned long flags;
 
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	if (!cpuhw->disabled)
 		goto out;
 
@@ -623,7 +623,7 @@ static void record_and_restart(struct pe
 static void perf_event_interrupt(struct pt_regs *regs)
 {
 	int i;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val;
 	int found = 0;
Index: linux/arch/powerpc/platforms/cell/interrupt.c
===================================================================
--- linux.orig/arch/powerpc/platforms/cell/interrupt.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/cell/interrupt.c	2013-08-28 14:15:09.959099532 -0500
@@ -82,7 +82,7 @@ static void iic_unmask(struct irq_data *
 
 static void iic_eoi(struct irq_data *d)
 {
-	struct iic *iic = &__get_cpu_var(cpu_iic);
+	struct iic *iic = this_cpu_ptr(&cpu_iic);
 	out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
 	BUG_ON(iic->eoi_ptr < 0);
 }
@@ -148,7 +148,7 @@ static unsigned int iic_get_irq(void)
 	struct iic *iic;
 	unsigned int virq;
 
-	iic = &__get_cpu_var(cpu_iic);
+	iic = this_cpu_ptr(&cpu_iic);
 	*(unsigned long *) &pending =
 		in_be64((u64 __iomem *) &iic->regs->pending_destr);
 	if (!(pending.flags & CBE_IIC_IRQ_VALID))
@@ -163,7 +163,7 @@ static unsigned int iic_get_irq(void)
 
 void iic_setup_cpu(void)
 {
-	out_be64(&__get_cpu_var(cpu_iic).regs->prio, 0xff);
+	out_be64(this_cpu_ptr(&cpu_iic.regs->prio), 0xff);
 }
 
 u8 iic_get_target_id(int cpu)
Index: linux/arch/powerpc/platforms/ps3/interrupt.c
===================================================================
--- linux.orig/arch/powerpc/platforms/ps3/interrupt.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/ps3/interrupt.c	2013-08-28 14:15:09.959099532 -0500
@@ -711,7 +711,7 @@ void __init ps3_register_ipi_irq(unsigne
 
 static unsigned int ps3_get_irq(void)
 {
-	struct ps3_private *pd = &__get_cpu_var(ps3_private);
+	struct ps3_private *pd = this_cpu_ptr(&ps3_private);
 	u64 x = (pd->bmp.status & pd->bmp.mask);
 	unsigned int plug;
 
Index: linux/arch/powerpc/platforms/pseries/dtl.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/dtl.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/dtl.c	2013-08-28 14:15:09.959099532 -0500
@@ -76,7 +76,7 @@ static atomic_t dtl_count;
  */
 static void consume_dtle(struct dtl_entry *dtle, u64 index)
 {
-	struct dtl_ring *dtlr = &__get_cpu_var(dtl_rings);
+	struct dtl_ring *dtlr = this_cpu_ptr(&dtl_rings);
 	struct dtl_entry *wp = dtlr->write_ptr;
 	struct lppaca *vpa = local_paca->lppaca_ptr;
 
Index: linux/arch/powerpc/platforms/pseries/hvCall_inst.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/hvCall_inst.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/hvCall_inst.c	2013-08-28 14:15:09.959099532 -0500
@@ -109,7 +109,7 @@ static void probe_hcall_entry(void *igno
 	if (opcode > MAX_HCALL_OPCODE)
 		return;
 
-	h = &__get_cpu_var(hcall_stats)[opcode / 4];
+	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 	h->tb_start = mftb();
 	h->purr_start = mfspr(SPRN_PURR);
 }
@@ -122,7 +122,7 @@ static void probe_hcall_exit(void *ignor
 	if (opcode > MAX_HCALL_OPCODE)
 		return;
 
-	h = &__get_cpu_var(hcall_stats)[opcode / 4];
+	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 	h->num_calls++;
 	h->tb_total += mftb() - h->tb_start;
 	h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
Index: linux/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/iommu.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/iommu.c	2013-08-28 14:15:09.963099491 -0500
@@ -201,7 +201,7 @@ static int tce_buildmulti_pSeriesLP(stru
 
 	local_irq_save(flags);	/* to protect tcep and the page behind it */
 
-	tcep = __get_cpu_var(tce_page);
+	tcep = __this_cpu_read(tce_page);
 
 	/* This is safe to do since interrupts are off when we're called
 	 * from iommu_alloc{,_sg}()
@@ -214,7 +214,7 @@ static int tce_buildmulti_pSeriesLP(stru
 			return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
 					    direction, attrs);
 		}
-		__get_cpu_var(tce_page) = tcep;
+		__this_cpu_write(tce_page, tcep);
 	}
 
 	rpn = __pa(uaddr) >> TCE_SHIFT;
@@ -399,7 +399,7 @@ static int tce_setrange_multi_pSeriesLP(
 	long l, limit;
 
 	local_irq_disable();	/* to protect tcep and the page behind it */
-	tcep = __get_cpu_var(tce_page);
+	tcep = __this_cpu_read(tce_page);
 
 	if (!tcep) {
 		tcep = (u64 *)__get_free_page(GFP_ATOMIC);
@@ -407,7 +407,7 @@ static int tce_setrange_multi_pSeriesLP(
 			local_irq_enable();
 			return -ENOMEM;
 		}
-		__get_cpu_var(tce_page) = tcep;
+		__this_cpu_write(tce_page, tcep);
 	}
 
 	proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
Index: linux/arch/powerpc/platforms/pseries/lpar.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/lpar.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/lpar.c	2013-08-28 14:15:09.963099491 -0500
@@ -490,7 +490,7 @@ static void pSeries_lpar_flush_hash_rang
 	unsigned long vpn;
 	unsigned long i, pix, rc;
 	unsigned long flags = 0;
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 	unsigned long param[9];
 	unsigned long hash, index, shift, hidx, slot;
@@ -665,7 +665,7 @@ void __trace_hcall_entry(unsigned long o
 
 	local_irq_save(flags);
 
-	depth = &__get_cpu_var(hcall_trace_depth);
+	depth = this_cpu_ptr(&hcall_trace_depth);
 
 	if (*depth)
 		goto out;
@@ -690,7 +690,7 @@ void __trace_hcall_exit(long opcode, uns
 
 	local_irq_save(flags);
 
-	depth = &__get_cpu_var(hcall_trace_depth);
+	depth = this_cpu_ptr(&hcall_trace_depth);
 
 	if (*depth)
 		goto out;
Index: linux/arch/powerpc/platforms/pseries/ras.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/ras.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/ras.c	2013-08-28 14:15:09.963099491 -0500
@@ -301,8 +301,8 @@ static struct rtas_error_log *fwnmi_get_
 	/* If it isn't an extended log we can use the per cpu 64bit buffer */
 	h = (struct rtas_error_log *)&savep[1];
 	if (!h->extended) {
-		memcpy(&__get_cpu_var(mce_data_buf), h, sizeof(__u64));
-		errhdr = (struct rtas_error_log *)&__get_cpu_var(mce_data_buf);
+		memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
+		errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
 	} else {
 		int len;
 
Index: linux/arch/powerpc/sysdev/xics/xics-common.c
===================================================================
--- linux.orig/arch/powerpc/sysdev/xics/xics-common.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/sysdev/xics/xics-common.c	2013-08-28 14:15:09.963099491 -0500
@@ -155,7 +155,7 @@ int __init xics_smp_probe(void)
 
 void xics_teardown_cpu(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	/*
 	 * we have to reset the cppr index to 0 because we're
Index: linux/arch/powerpc/kernel/iommu.c
===================================================================
--- linux.orig/arch/powerpc/kernel/iommu.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/iommu.c	2013-08-28 14:15:09.963099491 -0500
@@ -208,7 +208,7 @@ static unsigned long iommu_range_alloc(s
 	 * We don't need to disable preemption here because any CPU can
 	 * safely use any IOMMU pool.
 	 */
-	pool_nr = __raw_get_cpu_var(iommu_pool_hash) & (tbl->nr_pools - 1);
+	pool_nr = __this_cpu_read(iommu_pool_hash) & (tbl->nr_pools - 1);
 
 	if (largealloc)
 		pool = &(tbl->large_pool);

[gcv v3 25/35] powerpc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/powerpc/include/asm/cputime.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/cputime.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/cputime.h	2013-08-28 14:15:09.943099694 -0500
@@ -56,10 +56,10 @@ static inline unsigned long cputime_to_j
 static inline cputime_t cputime_to_scaled(const cputime_t ct)
 {
 	if (cpu_has_feature(CPU_FTR_SPURR) &&
-	    __get_cpu_var(cputime_last_delta))
+	    __this_cpu_read(cputime_last_delta))
 		return (__force u64) ct *
-			__get_cpu_var(cputime_scaled_last_delta) /
-			__get_cpu_var(cputime_last_delta);
+			__this_cpu_read(cputime_scaled_last_delta) /
+			__this_cpu_read(cputime_last_delta);
 	return ct;
 }
 
Index: linux/arch/powerpc/include/asm/hardirq.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/hardirq.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/hardirq.h	2013-08-28 14:15:09.943099694 -0500
@@ -19,7 +19,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpust
 
 #define __ARCH_IRQ_STAT
 
-#define local_softirq_pending()	__get_cpu_var(irq_stat).__softirq_pending
+#define local_softirq_pending()	__this_cpu_read(irq_stat.__softirq_pending)
 
 static inline void ack_bad_irq(unsigned int irq)
 {
Index: linux/arch/powerpc/include/asm/tlbflush.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/tlbflush.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/tlbflush.h	2013-08-28 14:15:09.943099694 -0500
@@ -107,14 +107,14 @@ extern void __flush_tlb_pending(struct p
 
 static inline void arch_enter_lazy_mmu_mode(void)
 {
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 
 	batch->active = 1;
 }
 
 static inline void arch_leave_lazy_mmu_mode(void)
 {
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 
 	if (batch->index)
 		__flush_tlb_pending(batch);
Index: linux/arch/powerpc/include/asm/xics.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/xics.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/xics.h	2013-08-28 14:15:09.943099694 -0500
@@ -97,7 +97,7 @@ DECLARE_PER_CPU(struct xics_cppr, xics_c
 
 static inline void xics_push_cppr(unsigned int vec)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	if (WARN_ON(os_cppr->index >= MAX_NUM_PRIORITIES - 1))
 		return;
@@ -110,7 +110,7 @@ static inline void xics_push_cppr(unsign
 
 static inline unsigned char xics_pop_cppr(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	if (WARN_ON(os_cppr->index < 1))
 		return LOWEST_PRIORITY;
@@ -120,7 +120,7 @@ static inline unsigned char xics_pop_cpp
 
 static inline void xics_set_base_cppr(unsigned char cppr)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	/* we only really want to set the priority when there's
 	 * just one cppr value on the stack
@@ -132,7 +132,7 @@ static inline void xics_set_base_cppr(un
 
 static inline unsigned char xics_cppr_top(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 	
 	return os_cppr->stack[os_cppr->index];
 }
Index: linux/arch/powerpc/kernel/dbell.c
===================================================================
--- linux.orig/arch/powerpc/kernel/dbell.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/dbell.c	2013-08-28 14:15:09.943099694 -0500
@@ -41,7 +41,7 @@ void doorbell_exception(struct pt_regs *
 
 	may_hard_irq_enable();
 
-	__get_cpu_var(irq_stat).doorbell_irqs++;
+	__this_cpu_inc(irq_stat.doorbell_irqs);
 
 	smp_ipi_demux();
 
Index: linux/arch/powerpc/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/powerpc/kernel/hw_breakpoint.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/hw_breakpoint.c	2013-08-28 14:15:09.943099694 -0500
@@ -64,7 +64,7 @@ int hw_breakpoint_slots(int type)
 int arch_install_hw_breakpoint(struct perf_event *bp)
 {
 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-	struct perf_event **slot = &__get_cpu_var(bp_per_reg);
+	struct perf_event **slot = this_cpu_ptr(&bp_per_reg);
 
 	*slot = bp;
 
@@ -89,7 +89,7 @@ int arch_install_hw_breakpoint(struct pe
  */
 void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 {
-	struct perf_event **slot = &__get_cpu_var(bp_per_reg);
+	struct perf_event **slot = this_cpu_ptr(&bp_per_reg);
 
 	if (*slot != bp) {
 		WARN_ONCE(1, "Can't find the breakpoint");
@@ -227,7 +227,7 @@ int __kprobes hw_breakpoint_handler(stru
 	 */
 	rcu_read_lock();
 
-	bp = __get_cpu_var(bp_per_reg);
+	bp = __this_cpu_read(bp_per_reg);
 	if (!bp)
 		goto out;
 	info = counter_arch_bp(bp);
Index: linux/arch/powerpc/kernel/irq.c
===================================================================
--- linux.orig/arch/powerpc/kernel/irq.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/irq.c	2013-08-28 14:15:55.854634913 -0500
@@ -114,7 +114,7 @@ static inline notrace void set_soft_enab
 static inline notrace int decrementer_check_overflow(void)
 {
  	u64 now = get_tb_or_rtc();
- 	u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
  
 	return now >= *next_tb;
 }
@@ -526,7 +526,7 @@ void do_IRQ(struct pt_regs *regs)
 	if (irq != NO_IRQ)
 		handle_one_irq(irq);
 	else
-		__get_cpu_var(irq_stat).spurious_irqs++;
+		__this_cpu_inc(irq_stat.spurious_irqs);
 
 	trace_irq_exit(regs);
 
Index: linux/arch/powerpc/kernel/kprobes.c
===================================================================
--- linux.orig/arch/powerpc/kernel/kprobes.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/kprobes.c	2013-08-28 14:15:09.947099653 -0500
@@ -118,7 +118,7 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_saved_msr = kcb->prev_kprobe.saved_msr;
 }
@@ -126,7 +126,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 				struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_saved_msr = regs->msr;
 }
 
@@ -191,7 +191,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
Index: linux/arch/powerpc/kernel/process.c
===================================================================
--- linux.orig/arch/powerpc/kernel/process.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/process.c	2013-08-28 14:15:09.947099653 -0500
@@ -453,7 +453,7 @@ static inline int set_dawr(struct arch_h
 
 int set_breakpoint(struct arch_hw_breakpoint *brk)
 {
-	__get_cpu_var(current_brk) = *brk;
+	__this_cpu_write(current_brk, *brk);
 
 	if (cpu_has_feature(CPU_FTR_DAWR))
 		return set_dawr(brk);
@@ -686,7 +686,7 @@ struct task_struct *__switch_to(struct t
  * schedule DABR
  */
 #ifndef CONFIG_HAVE_HW_BREAKPOINT
-	if (unlikely(hw_brk_match(&__get_cpu_var(current_brk), &new->thread.hw_brk)))
+	if (unlikely(hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
 		set_breakpoint(&new->thread.hw_brk);
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
@@ -700,7 +700,7 @@ struct task_struct *__switch_to(struct t
 	 * Collect processor utilization data per process
 	 */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
 		long unsigned start_tb, current_tb;
 		start_tb = old_thread->start_tb;
 		cu->current_tb = current_tb = mfspr(SPRN_PURR);
@@ -710,7 +710,7 @@ struct task_struct *__switch_to(struct t
 #endif /* CONFIG_PPC64 */
 
 #ifdef CONFIG_PPC_BOOK3S_64
-	batch = &__get_cpu_var(ppc64_tlb_batch);
+	batch = this_cpu_ptr(&ppc64_tlb_batch);
 	if (batch->active) {
 		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
 		if (batch->index)
@@ -735,7 +735,7 @@ struct task_struct *__switch_to(struct t
 #ifdef CONFIG_PPC_BOOK3S_64
 	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
 		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
-		batch = &__get_cpu_var(ppc64_tlb_batch);
+		batch = this_cpu_ptr(&ppc64_tlb_batch);
 		batch->active = 1;
 	}
 #endif /* CONFIG_PPC_BOOK3S_64 */
Index: linux/arch/powerpc/kernel/smp.c
===================================================================
--- linux.orig/arch/powerpc/kernel/smp.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/smp.c	2013-08-28 14:15:09.947099653 -0500
@@ -212,7 +212,7 @@ void smp_muxed_ipi_message_pass(int cpu,
 
 irqreturn_t smp_ipi_demux(void)
 {
-	struct cpu_messages *info = &__get_cpu_var(ipi_message);
+	struct cpu_messages *info = this_cpu_ptr(&ipi_message);
 	unsigned int all;
 
 	mb();	/* order any irq clear */
@@ -402,9 +402,9 @@ void generic_mach_cpu_die(void)
 	idle_task_exit();
 	cpu = smp_processor_id();
 	printk(KERN_DEBUG "CPU%d offline\n", cpu);
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 	smp_wmb();
-	while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
+	while (__this_cpu_read(cpu_state) != CPU_UP_PREPARE)
 		cpu_relax();
 }
 
Index: linux/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux.orig/arch/powerpc/kernel/sysfs.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/sysfs.c	2013-08-28 14:15:09.947099653 -0500
@@ -97,10 +97,10 @@ void ppc_enable_pmcs(void)
 	ppc_set_pmu_inuse(1);
 
 	/* Only need to enable them once */
-	if (__get_cpu_var(pmcs_enabled))
+	if (__this_cpu_read(pmcs_enabled))
 		return;
 
-	__get_cpu_var(pmcs_enabled) = 1;
+	__this_cpu_write(pmcs_enabled, 1);
 
 	if (ppc_md.enable_pmcs)
 		ppc_md.enable_pmcs();
Index: linux/arch/powerpc/kernel/time.c
===================================================================
--- linux.orig/arch/powerpc/kernel/time.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/time.c	2013-08-28 14:15:09.951099613 -0500
@@ -457,9 +457,9 @@ static inline void clear_irq_work_pendin
 
 DEFINE_PER_CPU(u8, irq_work_pending);
 
-#define set_irq_work_pending_flag()	__get_cpu_var(irq_work_pending) = 1
-#define test_irq_work_pending()		__get_cpu_var(irq_work_pending)
-#define clear_irq_work_pending()	__get_cpu_var(irq_work_pending) = 0
+#define set_irq_work_pending_flag()	__this_cpu_write(irq_work_pending, 1)
+#define test_irq_work_pending()		__this_cpu_read(irq_work_pending)
+#define clear_irq_work_pending()	__this_cpu_write(irq_work_pending, 0)
 
 #endif /* 32 vs 64 bit */
 
@@ -485,8 +485,8 @@ void arch_irq_work_raise(void)
 void timer_interrupt(struct pt_regs * regs)
 {
 	struct pt_regs *old_regs;
-	u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
-	struct clock_event_device *evt = &__get_cpu_var(decrementers);
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
+	struct clock_event_device *evt = this_cpu_ptr(&decrementers);
 	u64 now;
 
 	/* Ensure a positive value is written to the decrementer, or else
@@ -510,7 +510,7 @@ void timer_interrupt(struct pt_regs * re
 	 */
 	may_hard_irq_enable();
 
-	__get_cpu_var(irq_stat).timer_irqs++;
+	__this_cpu_inc(irq_stat.timer_irqs);
 
 #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
 	if (atomic_read(&ppc_n_lost_interrupts) != 0)
@@ -541,7 +541,7 @@ void timer_interrupt(struct pt_regs * re
 #ifdef CONFIG_PPC64
 	/* collect purr register values often, for accurate calculations */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
 		cu->current_tb = mfspr(SPRN_PURR);
 	}
 #endif
@@ -801,7 +801,7 @@ static void __init clocksource_init(void
 static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev)
 {
-	__get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;
+	__this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
 	set_dec(evt);
 	return 0;
 }
Index: linux/arch/powerpc/kernel/traps.c
===================================================================
--- linux.orig/arch/powerpc/kernel/traps.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/traps.c	2013-08-28 14:15:09.951099613 -0500
@@ -670,7 +670,7 @@ void machine_check_exception(struct pt_r
 	enum ctx_state prev_state = exception_enter();
 	int recover = 0;
 
-	__get_cpu_var(irq_stat).mce_exceptions++;
+	__this_cpu_inc(irq_stat.mce_exceptions);
 
 	/* See if any machine dependent calls. In theory, we would want
 	 * to call the CPU first, and call the ppc_md. one if the CPU
@@ -1436,7 +1436,7 @@ void vsx_unavailable_tm(struct pt_regs *
 
 void performance_monitor_exception(struct pt_regs *regs)
 {
-	__get_cpu_var(irq_stat).pmu_irqs++;
+	__this_cpu_inc(irq_stat.pmu_irqs);
 
 	perf_irq(regs);
 }
Index: linux/arch/powerpc/kvm/e500.c
===================================================================
--- linux.orig/arch/powerpc/kvm/e500.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kvm/e500.c	2013-08-28 14:15:09.951099613 -0500
@@ -74,11 +74,11 @@ static inline int local_sid_setup_one(st
 	unsigned long sid;
 	int ret = -1;
 
-	sid = ++(__get_cpu_var(pcpu_last_used_sid));
+	sid = __this_cpu_inc_return(pcpu_last_used_sid);
 	if (sid < NUM_TIDS) {
-		__get_cpu_var(pcpu_sids).entry[sid] = entry;
+		__this_cpu_write(pcpu_sids)entry[sid], entry);
 		entry->val = sid;
-		entry->pentry = &__get_cpu_var(pcpu_sids).entry[sid];
+		entry->pentry = this_cpu_ptr(&pcpu_sids.entry[sid]);
 		ret = sid;
 	}
 
@@ -106,8 +106,8 @@ static inline int local_sid_setup_one(st
 static inline int local_sid_lookup(struct id *entry)
 {
 	if (entry && entry->val != 0 &&
-	    __get_cpu_var(pcpu_sids).entry[entry->val] == entry &&
-	    entry->pentry == &__get_cpu_var(pcpu_sids).entry[entry->val])
+	    __this_cpu_read(pcpu_sids.entry[entry->val]) == entry &&
+	    entry->pentry == this_cpu_ptr(&pcpu_sids.entry[entry->val]))
 		return entry->val;
 	return -1;
 }
@@ -115,8 +115,8 @@ static inline int local_sid_lookup(struc
 /* Invalidate all id mappings on local core -- call with preempt disabled */
 static inline void local_sid_destroy_all(void)
 {
-	__get_cpu_var(pcpu_last_used_sid) = 0;
-	memset(&__get_cpu_var(pcpu_sids), 0, sizeof(__get_cpu_var(pcpu_sids)));
+	__this_cpu_write(pcpu_last_used_sid, 0);
+	memset(this_cpu_ptr(&pcpu_sids), 0, sizeof(pcpu_sids));
 }
 
 static void *kvmppc_e500_id_table_alloc(struct kvmppc_vcpu_e500 *vcpu_e500)
Index: linux/arch/powerpc/kvm/e500mc.c
===================================================================
--- linux.orig/arch/powerpc/kvm/e500mc.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kvm/e500mc.c	2013-08-28 14:15:09.951099613 -0500
@@ -139,9 +139,9 @@ void kvmppc_core_vcpu_load(struct kvm_vc
 	mtspr(SPRN_GESR, vcpu->arch.shared->esr);
 
 	if (vcpu->arch.oldpir != mfspr(SPRN_PIR) ||
-	    __get_cpu_var(last_vcpu_on_cpu) != vcpu) {
+	    __this_cpu_read(last_vcpu_on_cpu) != vcpu) {
 		kvmppc_e500_tlbil_all(vcpu_e500);
-		__get_cpu_var(last_vcpu_on_cpu) = vcpu;
+		__this_cpu_read(last_vcpu_on_cpu) = vcpu;
 	}
 
 	kvmppc_load_guest_fp(vcpu);
Index: linux/arch/powerpc/mm/hash_native_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/hash_native_64.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hash_native_64.c	2013-08-28 14:15:09.951099613 -0500
@@ -643,7 +643,7 @@ static void native_flush_hash_range(unsi
 	unsigned long want_v;
 	unsigned long flags;
 	real_pte_t pte;
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 	unsigned long psize = batch->psize;
 	int ssize = batch->ssize;
 	int i;
Index: linux/arch/powerpc/mm/hash_utils_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/hash_utils_64.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hash_utils_64.c	2013-08-28 14:15:09.955099572 -0500
@@ -1285,7 +1285,7 @@ void flush_hash_range(unsigned long numb
 	else {
 		int i;
 		struct ppc64_tlb_batch *batch =
-			&__get_cpu_var(ppc64_tlb_batch);
+			this_cpu_ptr(&ppc64_tlb_batch);
 
 		for (i = 0; i < number; i++)
 			flush_hash_page(batch->vpn[i], batch->pte[i],
Index: linux/arch/powerpc/mm/hugetlbpage-book3e.c
===================================================================
--- linux.orig/arch/powerpc/mm/hugetlbpage-book3e.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hugetlbpage-book3e.c	2013-08-28 14:15:09.955099572 -0500
@@ -80,14 +80,14 @@ void book3e_hugetlb_preload(struct vm_ar
 	ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
 
 	/* We have to use the CAM(TLB1) on FSL parts for hugepages */
-	index = __get_cpu_var(next_tlbcam_idx);
+	index = __this_cpu_read(next_tlbcam_idx);
 	mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));
 
 	/* Just round-robin the entries and wrap when we hit the end */
 	if (unlikely(index == ncams - 1))
-		__get_cpu_var(next_tlbcam_idx) = tlbcam_index;
+		__this_cpu_write(next_tlbcam_idx, tlbcam_index);
 	else
-		__get_cpu_var(next_tlbcam_idx)++;
+		__this_cpu_inc(next_tlbcam_idx);
 #endif
 	mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
 	mas2 = ea & ~((1UL << shift) - 1);
Index: linux/arch/powerpc/mm/hugetlbpage.c
===================================================================
--- linux.orig/arch/powerpc/mm/hugetlbpage.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hugetlbpage.c	2013-08-28 14:15:09.955099572 -0500
@@ -462,7 +462,7 @@ static void hugepd_free(struct mmu_gathe
 {
 	struct hugepd_freelist **batchp;
 
-	batchp = &__get_cpu_var(hugepd_freelist_cur);
+	batchp = this_cpu_ptr(&hugepd_freelist_cur);
 
 	if (atomic_read(&tlb->mm->mm_users) < 2 ||
 	    cpumask_equal(mm_cpumask(tlb->mm),
Index: linux/arch/powerpc/mm/stab.c
===================================================================
--- linux.orig/arch/powerpc/mm/stab.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/stab.c	2013-08-28 14:15:09.955099572 -0500
@@ -133,12 +133,12 @@ static int __ste_allocate(unsigned long
 	stab_entry = make_ste(get_paca()->stab_addr, GET_ESID(ea), vsid);
 
 	if (!is_kernel_addr(ea)) {
-		offset = __get_cpu_var(stab_cache_ptr);
+		offset = __this_cpu_read(stab_cache_ptr);
 		if (offset < NR_STAB_CACHE_ENTRIES)
-			__get_cpu_var(stab_cache[offset++]) = stab_entry;
+			__this_cpu_read(stab_cache[offset++]) = stab_entry;
 		else
 			offset = NR_STAB_CACHE_ENTRIES+1;
-		__get_cpu_var(stab_cache_ptr) = offset;
+		__this_cpu_write(stab_cache_ptr, offset);
 
 		/* Order update */
 		asm volatile("sync":::"memory");
@@ -177,12 +177,12 @@ void switch_stab(struct task_struct *tsk
 	 */
 	hard_irq_disable();
 
-	offset = __get_cpu_var(stab_cache_ptr);
+	offset = __this_cpu_read(stab_cache_ptr);
 	if (offset <= NR_STAB_CACHE_ENTRIES) {
 		int i;
 
 		for (i = 0; i < offset; i++) {
-			ste = stab + __get_cpu_var(stab_cache[i]);
+			ste = stab + __this_cpu_read(stab_cache[i]);
 			ste->esid_data = 0; /* invalidate entry */
 		}
 	} else {
@@ -206,7 +206,7 @@ void switch_stab(struct task_struct *tsk
 
 	asm volatile("sync; slbia; sync":::"memory");
 
-	__get_cpu_var(stab_cache_ptr) = 0;
+	__this_cpu_write(stab_cache_ptr, 0);
 
 	/* Now preload some entries for the new task */
 	if (test_tsk_thread_flag(tsk, TIF_32BIT))
Index: linux/arch/powerpc/perf/core-book3s.c
===================================================================
--- linux.orig/arch/powerpc/perf/core-book3s.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/perf/core-book3s.c	2013-08-28 14:15:09.959099532 -0500
@@ -332,7 +332,7 @@ static void power_pmu_bhrb_reset(void)
 
 static void power_pmu_bhrb_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!ppmu->bhrb_nr)
 		return;
@@ -347,7 +347,7 @@ static void power_pmu_bhrb_enable(struct
 
 static void power_pmu_bhrb_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!ppmu->bhrb_nr)
 		return;
@@ -961,7 +961,7 @@ static void power_pmu_disable(struct pmu
 	if (!ppmu)
 		return;
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuhw->disabled) {
 		/*
@@ -1027,7 +1027,7 @@ static void power_pmu_enable(struct pmu
 		return;
 	local_irq_save(flags);
 
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	if (!cpuhw->disabled)
 		goto out;
 
@@ -1211,7 +1211,7 @@ static int power_pmu_add(struct perf_eve
 	 * Add the event to the list (if there is room)
 	 * and check whether the total set is still feasible.
 	 */
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	n0 = cpuhw->n_events;
 	if (n0 >= ppmu->n_counter)
 		goto out;
@@ -1277,7 +1277,7 @@ static void power_pmu_del(struct perf_ev
 
 	power_pmu_read(event);
 
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	for (i = 0; i < cpuhw->n_events; ++i) {
 		if (event == cpuhw->event[i]) {
 			while (++i < cpuhw->n_events) {
@@ -1383,7 +1383,7 @@ static void power_pmu_stop(struct perf_e
  */
 void power_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	perf_pmu_disable(pmu);
 	cpuhw->group_flag |= PERF_EVENT_TXN;
@@ -1397,7 +1397,7 @@ void power_pmu_start_txn(struct pmu *pmu
  */
 void power_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	cpuhw->group_flag &= ~PERF_EVENT_TXN;
 	perf_pmu_enable(pmu);
@@ -1415,7 +1415,7 @@ int power_pmu_commit_txn(struct pmu *pmu
 
 	if (!ppmu)
 		return -EAGAIN;
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	n = cpuhw->n_events;
 	if (check_excludes(cpuhw->event, cpuhw->flags, 0, n))
 		return -EAGAIN;
@@ -1772,7 +1772,7 @@ static void record_and_restart(struct pe
 
 		if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) {
 			struct cpu_hw_events *cpuhw;
-			cpuhw = &__get_cpu_var(cpu_hw_events);
+			cpuhw = this_cpu_ptr(&cpu_hw_events);
 			power_pmu_bhrb_read(cpuhw);
 			data.br_stack = &cpuhw->bhrb_stack;
 		}
@@ -1845,7 +1845,7 @@ static bool pmc_overflow(unsigned long v
 static void perf_event_interrupt(struct pt_regs *regs)
 {
 	int i, j;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val[8];
 	int found, active;
Index: linux/arch/powerpc/perf/core-fsl-emb.c
===================================================================
--- linux.orig/arch/powerpc/perf/core-fsl-emb.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/perf/core-fsl-emb.c	2013-08-28 14:15:09.959099532 -0500
@@ -186,7 +186,7 @@ static void fsl_emb_pmu_disable(struct p
 	unsigned long flags;
 
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuhw->disabled) {
 		cpuhw->disabled = 1;
@@ -225,7 +225,7 @@ static void fsl_emb_pmu_enable(struct pm
 	unsigned long flags;
 
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	if (!cpuhw->disabled)
 		goto out;
 
@@ -623,7 +623,7 @@ static void record_and_restart(struct pe
 static void perf_event_interrupt(struct pt_regs *regs)
 {
 	int i;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val;
 	int found = 0;
Index: linux/arch/powerpc/platforms/cell/interrupt.c
===================================================================
--- linux.orig/arch/powerpc/platforms/cell/interrupt.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/cell/interrupt.c	2013-08-28 14:15:09.959099532 -0500
@@ -82,7 +82,7 @@ static void iic_unmask(struct irq_data *
 
 static void iic_eoi(struct irq_data *d)
 {
-	struct iic *iic = &__get_cpu_var(cpu_iic);
+	struct iic *iic = this_cpu_ptr(&cpu_iic);
 	out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
 	BUG_ON(iic->eoi_ptr < 0);
 }
@@ -148,7 +148,7 @@ static unsigned int iic_get_irq(void)
 	struct iic *iic;
 	unsigned int virq;
 
-	iic = &__get_cpu_var(cpu_iic);
+	iic = this_cpu_ptr(&cpu_iic);
 	*(unsigned long *) &pending =
 		in_be64((u64 __iomem *) &iic->regs->pending_destr);
 	if (!(pending.flags & CBE_IIC_IRQ_VALID))
@@ -163,7 +163,7 @@ static unsigned int iic_get_irq(void)
 
 void iic_setup_cpu(void)
 {
-	out_be64(&__get_cpu_var(cpu_iic).regs->prio, 0xff);
+	out_be64(this_cpu_ptr(&cpu_iic.regs->prio), 0xff);
 }
 
 u8 iic_get_target_id(int cpu)
Index: linux/arch/powerpc/platforms/ps3/interrupt.c
===================================================================
--- linux.orig/arch/powerpc/platforms/ps3/interrupt.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/ps3/interrupt.c	2013-08-28 14:15:09.959099532 -0500
@@ -711,7 +711,7 @@ void __init ps3_register_ipi_irq(unsigne
 
 static unsigned int ps3_get_irq(void)
 {
-	struct ps3_private *pd = &__get_cpu_var(ps3_private);
+	struct ps3_private *pd = this_cpu_ptr(&ps3_private);
 	u64 x = (pd->bmp.status & pd->bmp.mask);
 	unsigned int plug;
 
Index: linux/arch/powerpc/platforms/pseries/dtl.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/dtl.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/dtl.c	2013-08-28 14:15:09.959099532 -0500
@@ -76,7 +76,7 @@ static atomic_t dtl_count;
  */
 static void consume_dtle(struct dtl_entry *dtle, u64 index)
 {
-	struct dtl_ring *dtlr = &__get_cpu_var(dtl_rings);
+	struct dtl_ring *dtlr = this_cpu_ptr(&dtl_rings);
 	struct dtl_entry *wp = dtlr->write_ptr;
 	struct lppaca *vpa = local_paca->lppaca_ptr;
 
Index: linux/arch/powerpc/platforms/pseries/hvCall_inst.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/hvCall_inst.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/hvCall_inst.c	2013-08-28 14:15:09.959099532 -0500
@@ -109,7 +109,7 @@ static void probe_hcall_entry(void *igno
 	if (opcode > MAX_HCALL_OPCODE)
 		return;
 
-	h = &__get_cpu_var(hcall_stats)[opcode / 4];
+	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 	h->tb_start = mftb();
 	h->purr_start = mfspr(SPRN_PURR);
 }
@@ -122,7 +122,7 @@ static void probe_hcall_exit(void *ignor
 	if (opcode > MAX_HCALL_OPCODE)
 		return;
 
-	h = &__get_cpu_var(hcall_stats)[opcode / 4];
+	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 	h->num_calls++;
 	h->tb_total += mftb() - h->tb_start;
 	h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
Index: linux/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/iommu.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/iommu.c	2013-08-28 14:15:09.963099491 -0500
@@ -201,7 +201,7 @@ static int tce_buildmulti_pSeriesLP(stru
 
 	local_irq_save(flags);	/* to protect tcep and the page behind it */
 
-	tcep = __get_cpu_var(tce_page);
+	tcep = __this_cpu_read(tce_page);
 
 	/* This is safe to do since interrupts are off when we're called
 	 * from iommu_alloc{,_sg}()
@@ -214,7 +214,7 @@ static int tce_buildmulti_pSeriesLP(stru
 			return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
 					    direction, attrs);
 		}
-		__get_cpu_var(tce_page) = tcep;
+		__this_cpu_write(tce_page, tcep);
 	}
 
 	rpn = __pa(uaddr) >> TCE_SHIFT;
@@ -399,7 +399,7 @@ static int tce_setrange_multi_pSeriesLP(
 	long l, limit;
 
 	local_irq_disable();	/* to protect tcep and the page behind it */
-	tcep = __get_cpu_var(tce_page);
+	tcep = __this_cpu_read(tce_page);
 
 	if (!tcep) {
 		tcep = (u64 *)__get_free_page(GFP_ATOMIC);
@@ -407,7 +407,7 @@ static int tce_setrange_multi_pSeriesLP(
 			local_irq_enable();
 			return -ENOMEM;
 		}
-		__get_cpu_var(tce_page) = tcep;
+		__this_cpu_write(tce_page, tcep);
 	}
 
 	proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
Index: linux/arch/powerpc/platforms/pseries/lpar.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/lpar.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/lpar.c	2013-08-28 14:15:09.963099491 -0500
@@ -490,7 +490,7 @@ static void pSeries_lpar_flush_hash_rang
 	unsigned long vpn;
 	unsigned long i, pix, rc;
 	unsigned long flags = 0;
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 	unsigned long param[9];
 	unsigned long hash, index, shift, hidx, slot;
@@ -665,7 +665,7 @@ void __trace_hcall_entry(unsigned long o
 
 	local_irq_save(flags);
 
-	depth = &__get_cpu_var(hcall_trace_depth);
+	depth = this_cpu_ptr(&hcall_trace_depth);
 
 	if (*depth)
 		goto out;
@@ -690,7 +690,7 @@ void __trace_hcall_exit(long opcode, uns
 
 	local_irq_save(flags);
 
-	depth = &__get_cpu_var(hcall_trace_depth);
+	depth = this_cpu_ptr(&hcall_trace_depth);
 
 	if (*depth)
 		goto out;
Index: linux/arch/powerpc/platforms/pseries/ras.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/ras.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/ras.c	2013-08-28 14:15:09.963099491 -0500
@@ -301,8 +301,8 @@ static struct rtas_error_log *fwnmi_get_
 	/* If it isn't an extended log we can use the per cpu 64bit buffer */
 	h = (struct rtas_error_log *)&savep[1];
 	if (!h->extended) {
-		memcpy(&__get_cpu_var(mce_data_buf), h, sizeof(__u64));
-		errhdr = (struct rtas_error_log *)&__get_cpu_var(mce_data_buf);
+		memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
+		errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
 	} else {
 		int len;
 
Index: linux/arch/powerpc/sysdev/xics/xics-common.c
===================================================================
--- linux.orig/arch/powerpc/sysdev/xics/xics-common.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/sysdev/xics/xics-common.c	2013-08-28 14:15:09.963099491 -0500
@@ -155,7 +155,7 @@ int __init xics_smp_probe(void)
 
 void xics_teardown_cpu(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
 
 	/*
 	 * we have to reset the cppr index to 0 because we're
Index: linux/arch/powerpc/kernel/iommu.c
===================================================================
--- linux.orig/arch/powerpc/kernel/iommu.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/iommu.c	2013-08-28 14:15:09.963099491 -0500
@@ -208,7 +208,7 @@ static unsigned long iommu_range_alloc(s
 	 * We don't need to disable preemption here because any CPU can
 	 * safely use any IOMMU pool.
 	 */
-	pool_nr = __raw_get_cpu_var(iommu_pool_hash) & (tbl->nr_pools - 1);
+	pool_nr = __this_cpu_read(iommu_pool_hash) & (tbl->nr_pools - 1);
 
 	if (largealloc)
 		pool = &(tbl->large_pool);

Re: [gcv v3 25/35] powerpc: Replace __get_cpu_var uses

[Geert Uytterhoeven]

On Wed, Aug 28, 2013 at 9:48 PM, Christoph Lameter <cl@linux.com> wrote:
> 4. Retrieve the content of a percpu struct
>
>         DEFINE_PER_CPU(struct mystruct, y);
>         struct mystruct x = __get_cpu_var(y);
>
>    Converts to
>
>         memcpy(this_cpu_ptr(&x), y, sizeof(x));

Still not correct. I think it should be

        memcpy(x, this_cpu_ptr(&y), sizeof(x));

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [gcv v3 25/35] powerpc: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 28 Aug 2013, Geert Uytterhoeven wrote:

> On Wed, Aug 28, 2013 at 9:48 PM, Christoph Lameter <cl@linux.com> wrote:
> > 4. Retrieve the content of a percpu struct
> >
> >         DEFINE_PER_CPU(struct mystruct, y);
> >         struct mystruct x = __get_cpu_var(y);
> >
> >    Converts to
> >
> >         memcpy(this_cpu_ptr(&x), y, sizeof(x));
>
> Still not correct. I think it should be
>
>         memcpy(x, this_cpu_ptr(&y), sizeof(x));
>
> Gr{oetje,eeting}s,
>
>                         Geert
>

That was mentioned before in another patch of this set and this particular
patch was updated to the following:


Subject: powerpc: Replace __get_cpu_var uses
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Paul Mackerras <paulus@samba.org>

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided
and less registers are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too.

The patch set includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/powerpc/include/asm/cputime.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/cputime.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/cputime.h	2013-08-28 14:15:09.943099694 -0500
@@ -56,10 +56,10 @@ static inline unsigned long cputime_to_j
 static inline cputime_t cputime_to_scaled(const cputime_t ct)
 {
 	if (cpu_has_feature(CPU_FTR_SPURR) &&
-	    __get_cpu_var(cputime_last_delta))
+	    __this_cpu_read(cputime_last_delta))
 		return (__force u64) ct *
-			__get_cpu_var(cputime_scaled_last_delta) /
-			__get_cpu_var(cputime_last_delta);
+			__this_cpu_read(cputime_scaled_last_delta) /
+			__this_cpu_read(cputime_last_delta);
 	return ct;
 }

Index: linux/arch/powerpc/include/asm/hardirq.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/hardirq.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/hardirq.h	2013-08-28 14:15:09.943099694 -0500
@@ -19,7 +19,7 @@ DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpust

 #define __ARCH_IRQ_STAT

-#define local_softirq_pending()	__get_cpu_var(irq_stat).__softirq_pending
+#define local_softirq_pending()	__this_cpu_read(irq_stat.__softirq_pending)

 static inline void ack_bad_irq(unsigned int irq)
 {
Index: linux/arch/powerpc/include/asm/tlbflush.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/tlbflush.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/tlbflush.h	2013-08-28 14:15:09.943099694 -0500
@@ -107,14 +107,14 @@ extern void __flush_tlb_pending(struct p

 static inline void arch_enter_lazy_mmu_mode(void)
 {
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);

 	batch->active = 1;
 }

 static inline void arch_leave_lazy_mmu_mode(void)
 {
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);

 	if (batch->index)
 		__flush_tlb_pending(batch);
Index: linux/arch/powerpc/include/asm/xics.h
===================================================================
--- linux.orig/arch/powerpc/include/asm/xics.h	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/include/asm/xics.h	2013-08-28 14:15:09.943099694 -0500
@@ -97,7 +97,7 @@ DECLARE_PER_CPU(struct xics_cppr, xics_c

 static inline void xics_push_cppr(unsigned int vec)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);

 	if (WARN_ON(os_cppr->index >= MAX_NUM_PRIORITIES - 1))
 		return;
@@ -110,7 +110,7 @@ static inline void xics_push_cppr(unsign

 static inline unsigned char xics_pop_cppr(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);

 	if (WARN_ON(os_cppr->index < 1))
 		return LOWEST_PRIORITY;
@@ -120,7 +120,7 @@ static inline unsigned char xics_pop_cpp

 static inline void xics_set_base_cppr(unsigned char cppr)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);

 	/* we only really want to set the priority when there's
 	 * just one cppr value on the stack
@@ -132,7 +132,7 @@ static inline void xics_set_base_cppr(un

 static inline unsigned char xics_cppr_top(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);

 	return os_cppr->stack[os_cppr->index];
 }
Index: linux/arch/powerpc/kernel/dbell.c
===================================================================
--- linux.orig/arch/powerpc/kernel/dbell.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/dbell.c	2013-08-28 14:15:09.943099694 -0500
@@ -41,7 +41,7 @@ void doorbell_exception(struct pt_regs *

 	may_hard_irq_enable();

-	__get_cpu_var(irq_stat).doorbell_irqs++;
+	__this_cpu_inc(irq_stat.doorbell_irqs);

 	smp_ipi_demux();

Index: linux/arch/powerpc/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/powerpc/kernel/hw_breakpoint.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/hw_breakpoint.c	2013-08-28 14:15:09.943099694 -0500
@@ -64,7 +64,7 @@ int hw_breakpoint_slots(int type)
 int arch_install_hw_breakpoint(struct perf_event *bp)
 {
 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
-	struct perf_event **slot = &__get_cpu_var(bp_per_reg);
+	struct perf_event **slot = this_cpu_ptr(&bp_per_reg);

 	*slot = bp;

@@ -89,7 +89,7 @@ int arch_install_hw_breakpoint(struct pe
  */
 void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 {
-	struct perf_event **slot = &__get_cpu_var(bp_per_reg);
+	struct perf_event **slot = this_cpu_ptr(&bp_per_reg);

 	if (*slot != bp) {
 		WARN_ONCE(1, "Can't find the breakpoint");
@@ -227,7 +227,7 @@ int __kprobes hw_breakpoint_handler(stru
 	 */
 	rcu_read_lock();

-	bp = __get_cpu_var(bp_per_reg);
+	bp = __this_cpu_read(bp_per_reg);
 	if (!bp)
 		goto out;
 	info = counter_arch_bp(bp);
Index: linux/arch/powerpc/kernel/irq.c
===================================================================
--- linux.orig/arch/powerpc/kernel/irq.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/irq.c	2013-08-28 14:15:55.854634913 -0500
@@ -114,7 +114,7 @@ static inline notrace void set_soft_enab
 static inline notrace int decrementer_check_overflow(void)
 {
  	u64 now = get_tb_or_rtc();
- 	u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);

 	return now >= *next_tb;
 }
@@ -526,7 +526,7 @@ void do_IRQ(struct pt_regs *regs)
 	if (irq != NO_IRQ)
 		handle_one_irq(irq);
 	else
-		__get_cpu_var(irq_stat).spurious_irqs++;
+		__this_cpu_inc(irq_stat.spurious_irqs);

 	trace_irq_exit(regs);

Index: linux/arch/powerpc/kernel/kprobes.c
===================================================================
--- linux.orig/arch/powerpc/kernel/kprobes.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/kprobes.c	2013-08-28 14:15:09.947099653 -0500
@@ -118,7 +118,7 @@ static void __kprobes save_previous_kpro

 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_saved_msr = kcb->prev_kprobe.saved_msr;
 }
@@ -126,7 +126,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 				struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_saved_msr = regs->msr;
 }

@@ -191,7 +191,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
Index: linux/arch/powerpc/kernel/process.c
===================================================================
--- linux.orig/arch/powerpc/kernel/process.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/process.c	2013-08-28 14:15:09.947099653 -0500
@@ -453,7 +453,7 @@ static inline int set_dawr(struct arch_h

 int set_breakpoint(struct arch_hw_breakpoint *brk)
 {
-	__get_cpu_var(current_brk) = *brk;
+	__this_cpu_write(current_brk, *brk);

 	if (cpu_has_feature(CPU_FTR_DAWR))
 		return set_dawr(brk);
@@ -686,7 +686,7 @@ struct task_struct *__switch_to(struct t
  * schedule DABR
  */
 #ifndef CONFIG_HAVE_HW_BREAKPOINT
-	if (unlikely(hw_brk_match(&__get_cpu_var(current_brk), &new->thread.hw_brk)))
+	if (unlikely(hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
 		set_breakpoint(&new->thread.hw_brk);
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
@@ -700,7 +700,7 @@ struct task_struct *__switch_to(struct t
 	 * Collect processor utilization data per process
 	 */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
 		long unsigned start_tb, current_tb;
 		start_tb = old_thread->start_tb;
 		cu->current_tb = current_tb = mfspr(SPRN_PURR);
@@ -710,7 +710,7 @@ struct task_struct *__switch_to(struct t
 #endif /* CONFIG_PPC64 */

 #ifdef CONFIG_PPC_BOOK3S_64
-	batch = &__get_cpu_var(ppc64_tlb_batch);
+	batch = this_cpu_ptr(&ppc64_tlb_batch);
 	if (batch->active) {
 		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
 		if (batch->index)
@@ -735,7 +735,7 @@ struct task_struct *__switch_to(struct t
 #ifdef CONFIG_PPC_BOOK3S_64
 	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
 		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
-		batch = &__get_cpu_var(ppc64_tlb_batch);
+		batch = this_cpu_ptr(&ppc64_tlb_batch);
 		batch->active = 1;
 	}
 #endif /* CONFIG_PPC_BOOK3S_64 */
Index: linux/arch/powerpc/kernel/smp.c
===================================================================
--- linux.orig/arch/powerpc/kernel/smp.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/smp.c	2013-08-28 14:15:09.947099653 -0500
@@ -212,7 +212,7 @@ void smp_muxed_ipi_message_pass(int cpu,

 irqreturn_t smp_ipi_demux(void)
 {
-	struct cpu_messages *info = &__get_cpu_var(ipi_message);
+	struct cpu_messages *info = this_cpu_ptr(&ipi_message);
 	unsigned int all;

 	mb();	/* order any irq clear */
@@ -402,9 +402,9 @@ void generic_mach_cpu_die(void)
 	idle_task_exit();
 	cpu = smp_processor_id();
 	printk(KERN_DEBUG "CPU%d offline\n", cpu);
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 	smp_wmb();
-	while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
+	while (__this_cpu_read(cpu_state) != CPU_UP_PREPARE)
 		cpu_relax();
 }

Index: linux/arch/powerpc/kernel/sysfs.c
===================================================================
--- linux.orig/arch/powerpc/kernel/sysfs.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/sysfs.c	2013-08-28 14:15:09.947099653 -0500
@@ -97,10 +97,10 @@ void ppc_enable_pmcs(void)
 	ppc_set_pmu_inuse(1);

 	/* Only need to enable them once */
-	if (__get_cpu_var(pmcs_enabled))
+	if (__this_cpu_read(pmcs_enabled))
 		return;

-	__get_cpu_var(pmcs_enabled) = 1;
+	__this_cpu_write(pmcs_enabled, 1);

 	if (ppc_md.enable_pmcs)
 		ppc_md.enable_pmcs();
Index: linux/arch/powerpc/kernel/time.c
===================================================================
--- linux.orig/arch/powerpc/kernel/time.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/time.c	2013-08-28 14:15:09.951099613 -0500
@@ -457,9 +457,9 @@ static inline void clear_irq_work_pendin

 DEFINE_PER_CPU(u8, irq_work_pending);

-#define set_irq_work_pending_flag()	__get_cpu_var(irq_work_pending) = 1
-#define test_irq_work_pending()		__get_cpu_var(irq_work_pending)
-#define clear_irq_work_pending()	__get_cpu_var(irq_work_pending) = 0
+#define set_irq_work_pending_flag()	__this_cpu_write(irq_work_pending, 1)
+#define test_irq_work_pending()		__this_cpu_read(irq_work_pending)
+#define clear_irq_work_pending()	__this_cpu_write(irq_work_pending, 0)

 #endif /* 32 vs 64 bit */

@@ -485,8 +485,8 @@ void arch_irq_work_raise(void)
 void timer_interrupt(struct pt_regs * regs)
 {
 	struct pt_regs *old_regs;
-	u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
-	struct clock_event_device *evt = &__get_cpu_var(decrementers);
+	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
+	struct clock_event_device *evt = this_cpu_ptr(&decrementers);
 	u64 now;

 	/* Ensure a positive value is written to the decrementer, or else
@@ -510,7 +510,7 @@ void timer_interrupt(struct pt_regs * re
 	 */
 	may_hard_irq_enable();

-	__get_cpu_var(irq_stat).timer_irqs++;
+	__this_cpu_inc(irq_stat.timer_irqs);

 #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
 	if (atomic_read(&ppc_n_lost_interrupts) != 0)
@@ -541,7 +541,7 @@ void timer_interrupt(struct pt_regs * re
 #ifdef CONFIG_PPC64
 	/* collect purr register values often, for accurate calculations */
 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
-		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
 		cu->current_tb = mfspr(SPRN_PURR);
 	}
 #endif
@@ -801,7 +801,7 @@ static void __init clocksource_init(void
 static int decrementer_set_next_event(unsigned long evt,
 				      struct clock_event_device *dev)
 {
-	__get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;
+	__this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
 	set_dec(evt);
 	return 0;
 }
Index: linux/arch/powerpc/kernel/traps.c
===================================================================
--- linux.orig/arch/powerpc/kernel/traps.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/traps.c	2013-08-28 14:15:09.951099613 -0500
@@ -670,7 +670,7 @@ void machine_check_exception(struct pt_r
 	enum ctx_state prev_state = exception_enter();
 	int recover = 0;

-	__get_cpu_var(irq_stat).mce_exceptions++;
+	__this_cpu_inc(irq_stat.mce_exceptions);

 	/* See if any machine dependent calls. In theory, we would want
 	 * to call the CPU first, and call the ppc_md. one if the CPU
@@ -1436,7 +1436,7 @@ void vsx_unavailable_tm(struct pt_regs *

 void performance_monitor_exception(struct pt_regs *regs)
 {
-	__get_cpu_var(irq_stat).pmu_irqs++;
+	__this_cpu_inc(irq_stat.pmu_irqs);

 	perf_irq(regs);
 }
Index: linux/arch/powerpc/kvm/e500.c
===================================================================
--- linux.orig/arch/powerpc/kvm/e500.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kvm/e500.c	2013-08-28 14:15:09.951099613 -0500
@@ -74,11 +74,11 @@ static inline int local_sid_setup_one(st
 	unsigned long sid;
 	int ret = -1;

-	sid = ++(__get_cpu_var(pcpu_last_used_sid));
+	sid = __this_cpu_inc_return(pcpu_last_used_sid);
 	if (sid < NUM_TIDS) {
-		__get_cpu_var(pcpu_sids).entry[sid] = entry;
+		__this_cpu_write(pcpu_sids)entry[sid], entry);
 		entry->val = sid;
-		entry->pentry = &__get_cpu_var(pcpu_sids).entry[sid];
+		entry->pentry = this_cpu_ptr(&pcpu_sids.entry[sid]);
 		ret = sid;
 	}

@@ -106,8 +106,8 @@ static inline int local_sid_setup_one(st
 static inline int local_sid_lookup(struct id *entry)
 {
 	if (entry && entry->val != 0 &&
-	    __get_cpu_var(pcpu_sids).entry[entry->val] == entry &&
-	    entry->pentry == &__get_cpu_var(pcpu_sids).entry[entry->val])
+	    __this_cpu_read(pcpu_sids.entry[entry->val]) == entry &&
+	    entry->pentry == this_cpu_ptr(&pcpu_sids.entry[entry->val]))
 		return entry->val;
 	return -1;
 }
@@ -115,8 +115,8 @@ static inline int local_sid_lookup(struc
 /* Invalidate all id mappings on local core -- call with preempt disabled */
 static inline void local_sid_destroy_all(void)
 {
-	__get_cpu_var(pcpu_last_used_sid) = 0;
-	memset(&__get_cpu_var(pcpu_sids), 0, sizeof(__get_cpu_var(pcpu_sids)));
+	__this_cpu_write(pcpu_last_used_sid, 0);
+	memset(this_cpu_ptr(&pcpu_sids), 0, sizeof(pcpu_sids));
 }

 static void *kvmppc_e500_id_table_alloc(struct kvmppc_vcpu_e500 *vcpu_e500)
Index: linux/arch/powerpc/kvm/e500mc.c
===================================================================
--- linux.orig/arch/powerpc/kvm/e500mc.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kvm/e500mc.c	2013-08-28 14:15:09.951099613 -0500
@@ -139,9 +139,9 @@ void kvmppc_core_vcpu_load(struct kvm_vc
 	mtspr(SPRN_GESR, vcpu->arch.shared->esr);

 	if (vcpu->arch.oldpir != mfspr(SPRN_PIR) ||
-	    __get_cpu_var(last_vcpu_on_cpu) != vcpu) {
+	    __this_cpu_read(last_vcpu_on_cpu) != vcpu) {
 		kvmppc_e500_tlbil_all(vcpu_e500);
-		__get_cpu_var(last_vcpu_on_cpu) = vcpu;
+		__this_cpu_read(last_vcpu_on_cpu) = vcpu;
 	}

 	kvmppc_load_guest_fp(vcpu);
Index: linux/arch/powerpc/mm/hash_native_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/hash_native_64.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hash_native_64.c	2013-08-28 14:15:09.951099613 -0500
@@ -643,7 +643,7 @@ static void native_flush_hash_range(unsi
 	unsigned long want_v;
 	unsigned long flags;
 	real_pte_t pte;
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 	unsigned long psize = batch->psize;
 	int ssize = batch->ssize;
 	int i;
Index: linux/arch/powerpc/mm/hash_utils_64.c
===================================================================
--- linux.orig/arch/powerpc/mm/hash_utils_64.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hash_utils_64.c	2013-08-28 14:15:09.955099572 -0500
@@ -1285,7 +1285,7 @@ void flush_hash_range(unsigned long numb
 	else {
 		int i;
 		struct ppc64_tlb_batch *batch =
-			&__get_cpu_var(ppc64_tlb_batch);
+			this_cpu_ptr(&ppc64_tlb_batch);

 		for (i = 0; i < number; i++)
 			flush_hash_page(batch->vpn[i], batch->pte[i],
Index: linux/arch/powerpc/mm/hugetlbpage-book3e.c
===================================================================
--- linux.orig/arch/powerpc/mm/hugetlbpage-book3e.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hugetlbpage-book3e.c	2013-08-28 14:15:09.955099572 -0500
@@ -80,14 +80,14 @@ void book3e_hugetlb_preload(struct vm_ar
 	ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;

 	/* We have to use the CAM(TLB1) on FSL parts for hugepages */
-	index = __get_cpu_var(next_tlbcam_idx);
+	index = __this_cpu_read(next_tlbcam_idx);
 	mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));

 	/* Just round-robin the entries and wrap when we hit the end */
 	if (unlikely(index == ncams - 1))
-		__get_cpu_var(next_tlbcam_idx) = tlbcam_index;
+		__this_cpu_write(next_tlbcam_idx, tlbcam_index);
 	else
-		__get_cpu_var(next_tlbcam_idx)++;
+		__this_cpu_inc(next_tlbcam_idx);
 #endif
 	mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
 	mas2 = ea & ~((1UL << shift) - 1);
Index: linux/arch/powerpc/mm/hugetlbpage.c
===================================================================
--- linux.orig/arch/powerpc/mm/hugetlbpage.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/hugetlbpage.c	2013-08-28 14:15:09.955099572 -0500
@@ -462,7 +462,7 @@ static void hugepd_free(struct mmu_gathe
 {
 	struct hugepd_freelist **batchp;

-	batchp = &__get_cpu_var(hugepd_freelist_cur);
+	batchp = this_cpu_ptr(&hugepd_freelist_cur);

 	if (atomic_read(&tlb->mm->mm_users) < 2 ||
 	    cpumask_equal(mm_cpumask(tlb->mm),
Index: linux/arch/powerpc/mm/stab.c
===================================================================
--- linux.orig/arch/powerpc/mm/stab.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/mm/stab.c	2013-08-28 14:15:09.955099572 -0500
@@ -133,12 +133,12 @@ static int __ste_allocate(unsigned long
 	stab_entry = make_ste(get_paca()->stab_addr, GET_ESID(ea), vsid);

 	if (!is_kernel_addr(ea)) {
-		offset = __get_cpu_var(stab_cache_ptr);
+		offset = __this_cpu_read(stab_cache_ptr);
 		if (offset < NR_STAB_CACHE_ENTRIES)
-			__get_cpu_var(stab_cache[offset++]) = stab_entry;
+			__this_cpu_read(stab_cache[offset++]) = stab_entry;
 		else
 			offset = NR_STAB_CACHE_ENTRIES+1;
-		__get_cpu_var(stab_cache_ptr) = offset;
+		__this_cpu_write(stab_cache_ptr, offset);

 		/* Order update */
 		asm volatile("sync":::"memory");
@@ -177,12 +177,12 @@ void switch_stab(struct task_struct *tsk
 	 */
 	hard_irq_disable();

-	offset = __get_cpu_var(stab_cache_ptr);
+	offset = __this_cpu_read(stab_cache_ptr);
 	if (offset <= NR_STAB_CACHE_ENTRIES) {
 		int i;

 		for (i = 0; i < offset; i++) {
-			ste = stab + __get_cpu_var(stab_cache[i]);
+			ste = stab + __this_cpu_read(stab_cache[i]);
 			ste->esid_data = 0; /* invalidate entry */
 		}
 	} else {
@@ -206,7 +206,7 @@ void switch_stab(struct task_struct *tsk

 	asm volatile("sync; slbia; sync":::"memory");

-	__get_cpu_var(stab_cache_ptr) = 0;
+	__this_cpu_write(stab_cache_ptr, 0);

 	/* Now preload some entries for the new task */
 	if (test_tsk_thread_flag(tsk, TIF_32BIT))
Index: linux/arch/powerpc/perf/core-book3s.c
===================================================================
--- linux.orig/arch/powerpc/perf/core-book3s.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/perf/core-book3s.c	2013-08-28 14:15:09.959099532 -0500
@@ -332,7 +332,7 @@ static void power_pmu_bhrb_reset(void)

 static void power_pmu_bhrb_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);

 	if (!ppmu->bhrb_nr)
 		return;
@@ -347,7 +347,7 @@ static void power_pmu_bhrb_enable(struct

 static void power_pmu_bhrb_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);

 	if (!ppmu->bhrb_nr)
 		return;
@@ -961,7 +961,7 @@ static void power_pmu_disable(struct pmu
 	if (!ppmu)
 		return;
 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);

 	if (!cpuhw->disabled) {
 		/*
@@ -1027,7 +1027,7 @@ static void power_pmu_enable(struct pmu
 		return;
 	local_irq_save(flags);

-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	if (!cpuhw->disabled)
 		goto out;

@@ -1211,7 +1211,7 @@ static int power_pmu_add(struct perf_eve
 	 * Add the event to the list (if there is room)
 	 * and check whether the total set is still feasible.
 	 */
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	n0 = cpuhw->n_events;
 	if (n0 >= ppmu->n_counter)
 		goto out;
@@ -1277,7 +1277,7 @@ static void power_pmu_del(struct perf_ev

 	power_pmu_read(event);

-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	for (i = 0; i < cpuhw->n_events; ++i) {
 		if (event == cpuhw->event[i]) {
 			while (++i < cpuhw->n_events) {
@@ -1383,7 +1383,7 @@ static void power_pmu_stop(struct perf_e
  */
 void power_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);

 	perf_pmu_disable(pmu);
 	cpuhw->group_flag |= PERF_EVENT_TXN;
@@ -1397,7 +1397,7 @@ void power_pmu_start_txn(struct pmu *pmu
  */
 void power_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);

 	cpuhw->group_flag &= ~PERF_EVENT_TXN;
 	perf_pmu_enable(pmu);
@@ -1415,7 +1415,7 @@ int power_pmu_commit_txn(struct pmu *pmu

 	if (!ppmu)
 		return -EAGAIN;
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	n = cpuhw->n_events;
 	if (check_excludes(cpuhw->event, cpuhw->flags, 0, n))
 		return -EAGAIN;
@@ -1772,7 +1772,7 @@ static void record_and_restart(struct pe

 		if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) {
 			struct cpu_hw_events *cpuhw;
-			cpuhw = &__get_cpu_var(cpu_hw_events);
+			cpuhw = this_cpu_ptr(&cpu_hw_events);
 			power_pmu_bhrb_read(cpuhw);
 			data.br_stack = &cpuhw->bhrb_stack;
 		}
@@ -1845,7 +1845,7 @@ static bool pmc_overflow(unsigned long v
 static void perf_event_interrupt(struct pt_regs *regs)
 {
 	int i, j;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val[8];
 	int found, active;
Index: linux/arch/powerpc/perf/core-fsl-emb.c
===================================================================
--- linux.orig/arch/powerpc/perf/core-fsl-emb.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/perf/core-fsl-emb.c	2013-08-28 14:15:09.959099532 -0500
@@ -186,7 +186,7 @@ static void fsl_emb_pmu_disable(struct p
 	unsigned long flags;

 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);

 	if (!cpuhw->disabled) {
 		cpuhw->disabled = 1;
@@ -225,7 +225,7 @@ static void fsl_emb_pmu_enable(struct pm
 	unsigned long flags;

 	local_irq_save(flags);
-	cpuhw = &__get_cpu_var(cpu_hw_events);
+	cpuhw = this_cpu_ptr(&cpu_hw_events);
 	if (!cpuhw->disabled)
 		goto out;

@@ -623,7 +623,7 @@ static void record_and_restart(struct pe
 static void perf_event_interrupt(struct pt_regs *regs)
 {
 	int i;
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	unsigned long val;
 	int found = 0;
Index: linux/arch/powerpc/platforms/cell/interrupt.c
===================================================================
--- linux.orig/arch/powerpc/platforms/cell/interrupt.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/cell/interrupt.c	2013-08-28 14:15:09.959099532 -0500
@@ -82,7 +82,7 @@ static void iic_unmask(struct irq_data *

 static void iic_eoi(struct irq_data *d)
 {
-	struct iic *iic = &__get_cpu_var(cpu_iic);
+	struct iic *iic = this_cpu_ptr(&cpu_iic);
 	out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
 	BUG_ON(iic->eoi_ptr < 0);
 }
@@ -148,7 +148,7 @@ static unsigned int iic_get_irq(void)
 	struct iic *iic;
 	unsigned int virq;

-	iic = &__get_cpu_var(cpu_iic);
+	iic = this_cpu_ptr(&cpu_iic);
 	*(unsigned long *) &pending =
 		in_be64((u64 __iomem *) &iic->regs->pending_destr);
 	if (!(pending.flags & CBE_IIC_IRQ_VALID))
@@ -163,7 +163,7 @@ static unsigned int iic_get_irq(void)

 void iic_setup_cpu(void)
 {
-	out_be64(&__get_cpu_var(cpu_iic).regs->prio, 0xff);
+	out_be64(this_cpu_ptr(&cpu_iic.regs->prio), 0xff);
 }

 u8 iic_get_target_id(int cpu)
Index: linux/arch/powerpc/platforms/ps3/interrupt.c
===================================================================
--- linux.orig/arch/powerpc/platforms/ps3/interrupt.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/ps3/interrupt.c	2013-08-28 14:15:09.959099532 -0500
@@ -711,7 +711,7 @@ void __init ps3_register_ipi_irq(unsigne

 static unsigned int ps3_get_irq(void)
 {
-	struct ps3_private *pd = &__get_cpu_var(ps3_private);
+	struct ps3_private *pd = this_cpu_ptr(&ps3_private);
 	u64 x = (pd->bmp.status & pd->bmp.mask);
 	unsigned int plug;

Index: linux/arch/powerpc/platforms/pseries/dtl.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/dtl.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/dtl.c	2013-08-28 14:15:09.959099532 -0500
@@ -76,7 +76,7 @@ static atomic_t dtl_count;
  */
 static void consume_dtle(struct dtl_entry *dtle, u64 index)
 {
-	struct dtl_ring *dtlr = &__get_cpu_var(dtl_rings);
+	struct dtl_ring *dtlr = this_cpu_ptr(&dtl_rings);
 	struct dtl_entry *wp = dtlr->write_ptr;
 	struct lppaca *vpa = local_paca->lppaca_ptr;

Index: linux/arch/powerpc/platforms/pseries/hvCall_inst.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/hvCall_inst.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/hvCall_inst.c	2013-08-28 14:15:09.959099532 -0500
@@ -109,7 +109,7 @@ static void probe_hcall_entry(void *igno
 	if (opcode > MAX_HCALL_OPCODE)
 		return;

-	h = &__get_cpu_var(hcall_stats)[opcode / 4];
+	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 	h->tb_start = mftb();
 	h->purr_start = mfspr(SPRN_PURR);
 }
@@ -122,7 +122,7 @@ static void probe_hcall_exit(void *ignor
 	if (opcode > MAX_HCALL_OPCODE)
 		return;

-	h = &__get_cpu_var(hcall_stats)[opcode / 4];
+	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
 	h->num_calls++;
 	h->tb_total += mftb() - h->tb_start;
 	h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
Index: linux/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/iommu.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/iommu.c	2013-08-28 14:15:09.963099491 -0500
@@ -201,7 +201,7 @@ static int tce_buildmulti_pSeriesLP(stru

 	local_irq_save(flags);	/* to protect tcep and the page behind it */

-	tcep = __get_cpu_var(tce_page);
+	tcep = __this_cpu_read(tce_page);

 	/* This is safe to do since interrupts are off when we're called
 	 * from iommu_alloc{,_sg}()
@@ -214,7 +214,7 @@ static int tce_buildmulti_pSeriesLP(stru
 			return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
 					    direction, attrs);
 		}
-		__get_cpu_var(tce_page) = tcep;
+		__this_cpu_write(tce_page, tcep);
 	}

 	rpn = __pa(uaddr) >> TCE_SHIFT;
@@ -399,7 +399,7 @@ static int tce_setrange_multi_pSeriesLP(
 	long l, limit;

 	local_irq_disable();	/* to protect tcep and the page behind it */
-	tcep = __get_cpu_var(tce_page);
+	tcep = __this_cpu_read(tce_page);

 	if (!tcep) {
 		tcep = (u64 *)__get_free_page(GFP_ATOMIC);
@@ -407,7 +407,7 @@ static int tce_setrange_multi_pSeriesLP(
 			local_irq_enable();
 			return -ENOMEM;
 		}
-		__get_cpu_var(tce_page) = tcep;
+		__this_cpu_write(tce_page, tcep);
 	}

 	proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
Index: linux/arch/powerpc/platforms/pseries/lpar.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/lpar.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/lpar.c	2013-08-28 14:15:09.963099491 -0500
@@ -490,7 +490,7 @@ static void pSeries_lpar_flush_hash_rang
 	unsigned long vpn;
 	unsigned long i, pix, rc;
 	unsigned long flags = 0;
-	struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
+	struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 	int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 	unsigned long param[9];
 	unsigned long hash, index, shift, hidx, slot;
@@ -665,7 +665,7 @@ void __trace_hcall_entry(unsigned long o

 	local_irq_save(flags);

-	depth = &__get_cpu_var(hcall_trace_depth);
+	depth = this_cpu_ptr(&hcall_trace_depth);

 	if (*depth)
 		goto out;
@@ -690,7 +690,7 @@ void __trace_hcall_exit(long opcode, uns

 	local_irq_save(flags);

-	depth = &__get_cpu_var(hcall_trace_depth);
+	depth = this_cpu_ptr(&hcall_trace_depth);

 	if (*depth)
 		goto out;
Index: linux/arch/powerpc/platforms/pseries/ras.c
===================================================================
--- linux.orig/arch/powerpc/platforms/pseries/ras.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/platforms/pseries/ras.c	2013-08-28 14:15:09.963099491 -0500
@@ -301,8 +301,8 @@ static struct rtas_error_log *fwnmi_get_
 	/* If it isn't an extended log we can use the per cpu 64bit buffer */
 	h = (struct rtas_error_log *)&savep[1];
 	if (!h->extended) {
-		memcpy(&__get_cpu_var(mce_data_buf), h, sizeof(__u64));
-		errhdr = (struct rtas_error_log *)&__get_cpu_var(mce_data_buf);
+		memcpy(this_cpu_ptr(&mce_data_buf), h, sizeof(__u64));
+		errhdr = (struct rtas_error_log *)this_cpu_ptr(&mce_data_buf);
 	} else {
 		int len;

Index: linux/arch/powerpc/sysdev/xics/xics-common.c
===================================================================
--- linux.orig/arch/powerpc/sysdev/xics/xics-common.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/sysdev/xics/xics-common.c	2013-08-28 14:15:09.963099491 -0500
@@ -155,7 +155,7 @@ int __init xics_smp_probe(void)

 void xics_teardown_cpu(void)
 {
-	struct xics_cppr *os_cppr = &__get_cpu_var(xics_cppr);
+	struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);

 	/*
 	 * we have to reset the cppr index to 0 because we're
Index: linux/arch/powerpc/kernel/iommu.c
===================================================================
--- linux.orig/arch/powerpc/kernel/iommu.c	2013-08-28 14:15:09.971099410 -0500
+++ linux/arch/powerpc/kernel/iommu.c	2013-08-28 14:15:09.963099491 -0500
@@ -208,7 +208,7 @@ static unsigned long iommu_range_alloc(s
 	 * We don't need to disable preemption here because any CPU can
 	 * safely use any IOMMU pool.
 	 */
-	pool_nr = __raw_get_cpu_var(iommu_pool_hash) & (tbl->nr_pools - 1);
+	pool_nr = __this_cpu_read(iommu_pool_hash) & (tbl->nr_pools - 1);

 	if (largealloc)
 		pool = &(tbl->large_pool);

[gcv v3 05/35] time: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/hrtimer.c
===================================================================
--- linux.orig/kernel/hrtimer.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/hrtimer.c	2013-08-26 14:21:24.540227691 -0500
@@ -597,7 +597,7 @@ hrtimer_force_reprogram(struct hrtimer_c
 static int hrtimer_reprogram(struct hrtimer *timer,
 			     struct hrtimer_clock_base *base)
 {
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 	int res;
 
@@ -680,7 +680,7 @@ static inline ktime_t hrtimer_update_bas
  */
 static void retrigger_next_event(void *arg)
 {
-	struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
 
 	if (!hrtimer_hres_active())
 		return;
@@ -954,7 +954,7 @@ remove_hrtimer(struct hrtimer *timer, st
 		 */
 		debug_deactivate(timer);
 		timer_stats_hrtimer_clear_start_info(timer);
-		reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
+		reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
 		/*
 		 * We must preserve the CALLBACK state flag here,
 		 * otherwise we could move the timer base in
@@ -1009,7 +1009,7 @@ int __hrtimer_start_range_ns(struct hrti
 	 *
 	 * XXX send_remote_softirq() ?
 	 */
-	if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
+	if (leftmost && new_base->cpu_base == this_cpu_ptr(&hrtimer_bases)
 		&& hrtimer_enqueue_reprogram(timer, new_base)) {
 		if (wakeup) {
 			/*
@@ -1142,7 +1142,7 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining)
  */
 ktime_t hrtimer_get_next_event(void)
 {
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base = cpu_base->clock_base;
 	ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
 	unsigned long flags;
@@ -1183,7 +1183,7 @@ static void __hrtimer_init(struct hrtime
 
 	memset(timer, 0, sizeof(struct hrtimer));
 
-	cpu_base = &__raw_get_cpu_var(hrtimer_bases);
+	cpu_base = __this_cpu_ptr(&hrtimer_bases);
 
 	if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
 		clock_id = CLOCK_MONOTONIC;
@@ -1226,7 +1226,7 @@ int hrtimer_get_res(const clockid_t whic
 	struct hrtimer_cpu_base *cpu_base;
 	int base = hrtimer_clockid_to_base(which_clock);
 
-	cpu_base = &__raw_get_cpu_var(hrtimer_bases);
+	cpu_base = __this_cpu_ptr(&hrtimer_bases);
 	*tp = ktime_to_timespec(cpu_base->clock_base[base].resolution);
 
 	return 0;
@@ -1281,7 +1281,7 @@ static void __run_hrtimer(struct hrtimer
  */
 void hrtimer_interrupt(struct clock_event_device *dev)
 {
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t expires_next, now, entry_time, delta;
 	int i, retries = 0;
 
@@ -1415,7 +1415,7 @@ static void __hrtimer_peek_ahead_timers(
 	if (!hrtimer_hres_active())
 		return;
 
-	td = &__get_cpu_var(tick_cpu_device);
+	td = this_cpu_ptr(&tick_cpu_device);
 	if (td && td->evtdev)
 		hrtimer_interrupt(td->evtdev);
 }
@@ -1479,7 +1479,7 @@ void hrtimer_run_pending(void)
 void hrtimer_run_queues(void)
 {
 	struct timerqueue_node *node;
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base;
 	int index, gettime = 1;
 
@@ -1717,7 +1717,7 @@ static void migrate_hrtimers(int scpu)
 
 	local_irq_disable();
 	old_base = &per_cpu(hrtimer_bases, scpu);
-	new_base = &__get_cpu_var(hrtimer_bases);
+	new_base = this_cpu_ptr(&hrtimer_bases);
 	/*
 	 * The caller is globally serialized and nobody else
 	 * takes two locks at once, deadlock is not possible.
Index: linux/kernel/irq_work.c
===================================================================
--- linux.orig/kernel/irq_work.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/irq_work.c	2013-08-26 14:21:24.540227691 -0500
@@ -70,7 +70,7 @@ void irq_work_queue(struct irq_work *wor
 	/* Queue the entry and raise the IPI if needed. */
 	preempt_disable();
 
-	llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
+	llist_add(&work->llnode, this_cpu_ptr(&irq_work_list));
 
 	/*
 	 * If the work is not "lazy" or the tick is stopped, raise the irq
@@ -90,7 +90,7 @@ bool irq_work_needs_cpu(void)
 {
 	struct llist_head *this_list;
 
-	this_list = &__get_cpu_var(irq_work_list);
+	this_list = this_cpu_ptr(&irq_work_list);
 	if (llist_empty(this_list))
 		return false;
 
@@ -115,7 +115,7 @@ static void __irq_work_run(void)
 	__this_cpu_write(irq_work_raised, 0);
 	barrier();
 
-	this_list = &__get_cpu_var(irq_work_list);
+	this_list = this_cpu_ptr(&irq_work_list);
 	if (llist_empty(this_list))
 		return;
 
Index: linux/kernel/sched/clock.c
===================================================================
--- linux.orig/kernel/sched/clock.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/sched/clock.c	2013-08-26 14:21:24.540227691 -0500
@@ -94,7 +94,7 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(str
 
 static inline struct sched_clock_data *this_scd(void)
 {
-	return &__get_cpu_var(sched_clock_data);
+	return this_cpu_ptr(&sched_clock_data);
 }
 
 static inline struct sched_clock_data *cpu_sdc(int cpu)
Index: linux/kernel/softirq.c
===================================================================
--- linux.orig/kernel/softirq.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/softirq.c	2013-08-26 14:21:24.540227691 -0500
@@ -466,7 +466,7 @@ static void tasklet_action(struct softir
 	local_irq_disable();
 	list = __this_cpu_read(tasklet_vec.head);
 	__this_cpu_write(tasklet_vec.head, NULL);
-	__this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head);
+	__this_cpu_write(tasklet_vec.tail, this_cpu_ptr(&tasklet_vec.head));
 	local_irq_enable();
 
 	while (list) {
@@ -501,7 +501,7 @@ static void tasklet_hi_action(struct sof
 	local_irq_disable();
 	list = __this_cpu_read(tasklet_hi_vec.head);
 	__this_cpu_write(tasklet_hi_vec.head, NULL);
-	__this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head);
+	__this_cpu_write(tasklet_hi_vec.tail, this_cpu_ptr(&tasklet_hi_vec.head));
 	local_irq_enable();
 
 	while (list) {
@@ -618,7 +618,7 @@ EXPORT_PER_CPU_SYMBOL(softirq_work_list)
 
 static void __local_trigger(struct call_single_data *cp, int softirq)
 {
-	struct list_head *head = &__get_cpu_var(softirq_work_list[softirq]);
+	struct list_head *head = this_cpu_ptr(&softirq_work_list[softirq]);
 
 	list_add_tail(&cp->list, head);
 
@@ -718,7 +718,7 @@ static int remote_softirq_cpu_notify(str
 			if (list_empty(head))
 				continue;
 
-			local_head = &__get_cpu_var(softirq_work_list[i]);
+			local_head = this_cpu_ptr(&softirq_work_list[i]);
 			list_splice_init(head, local_head);
 			raise_softirq_irqoff(i);
 		}
Index: linux/kernel/time/tick-common.c
===================================================================
--- linux.orig/kernel/time/tick-common.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/time/tick-common.c	2013-08-26 14:21:24.544227649 -0500
@@ -208,7 +208,7 @@ static void tick_setup_device(struct tic
 
 void tick_install_replacement(struct clock_event_device *newdev)
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 	int cpu = smp_processor_id();
 
 	clockevents_exchange_device(td->evtdev, newdev);
@@ -358,14 +358,14 @@ void tick_shutdown(unsigned int *cpup)
 
 void tick_suspend(void)
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 
 	clockevents_shutdown(td->evtdev);
 }
 
 void tick_resume(void)
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 	int broadcast = tick_resume_broadcast();
 
 	clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
Index: linux/kernel/time/tick-oneshot.c
===================================================================
--- linux.orig/kernel/time/tick-oneshot.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/time/tick-oneshot.c	2013-08-26 14:21:24.544227649 -0500
@@ -59,7 +59,7 @@ void tick_setup_oneshot(struct clock_eve
  */
 int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 	struct clock_event_device *dev = td->evtdev;
 
 	if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
Index: linux/kernel/time/tick-sched.c
===================================================================
--- linux.orig/kernel/time/tick-sched.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/time/tick-sched.c	2013-08-26 14:21:24.540227691 -0500
@@ -199,7 +199,7 @@ static void tick_nohz_restart_sched_tick
  */
 void tick_nohz_full_check(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (tick_nohz_full_cpu(smp_processor_id())) {
 		if (ts->tick_stopped && !is_idle_task(current)) {
@@ -225,7 +225,7 @@ static DEFINE_PER_CPU(struct irq_work, n
 void tick_nohz_full_kick(void)
 {
 	if (tick_nohz_full_cpu(smp_processor_id()))
-		irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
+		irq_work_queue(this_cpu_ptr(&nohz_full_kick_work));
 }
 
 static void nohz_full_kick_ipi(void *info)
@@ -536,7 +536,7 @@ static ktime_t tick_nohz_stop_sched_tick
 	unsigned long seq, last_jiffies, next_jiffies, delta_jiffies;
 	ktime_t last_update, expires, ret = { .tv64 = 0 };
 	unsigned long rcu_delta_jiffies;
-	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+	struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
 	u64 time_delta;
 
 	/* Read jiffies and the time when jiffies were updated last */
@@ -801,7 +801,7 @@ void tick_nohz_idle_enter(void)
 
 	local_irq_disable();
 
-	ts = &__get_cpu_var(tick_cpu_sched);
+	ts = this_cpu_ptr(&tick_cpu_sched);
 	/*
 	 * set ts->inidle unconditionally. even if the system did not
 	 * switch to nohz mode the cpu frequency governers rely on the
@@ -824,7 +824,7 @@ EXPORT_SYMBOL_GPL(tick_nohz_idle_enter);
  */
 void tick_nohz_irq_exit(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (ts->inidle)
 		__tick_nohz_idle_enter(ts);
@@ -839,7 +839,7 @@ void tick_nohz_irq_exit(void)
  */
 ktime_t tick_nohz_get_sleep_length(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	return ts->sleep_length;
 }
@@ -953,7 +953,7 @@ static int tick_nohz_reprogram(struct ti
  */
 static void tick_nohz_handler(struct clock_event_device *dev)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 	struct pt_regs *regs = get_irq_regs();
 	ktime_t now = ktime_get();
 
@@ -973,7 +973,7 @@ static void tick_nohz_handler(struct clo
  */
 static void tick_nohz_switch_to_nohz(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 	ktime_t next;
 
 	if (!tick_nohz_enabled)
@@ -1111,7 +1111,7 @@ early_param("skew_tick", skew_tick);
  */
 void tick_setup_sched_timer(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 	ktime_t now = ktime_get();
 
 	/*
@@ -1178,7 +1178,7 @@ void tick_clock_notify(void)
  */
 void tick_oneshot_notify(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	set_bit(0, &ts->check_clocks);
 }
@@ -1193,7 +1193,7 @@ void tick_oneshot_notify(void)
  */
 int tick_check_oneshot_change(int allow_nohz)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (!test_and_clear_bit(0, &ts->check_clocks))
 		return 0;
Index: linux/kernel/timer.c
===================================================================
--- linux.orig/kernel/timer.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/timer.c	2013-08-26 14:21:24.544227649 -0500
@@ -621,7 +621,7 @@ static inline void debug_assert_init(str
 static void do_init_timer(struct timer_list *timer, unsigned int flags,
 			  const char *name, struct lock_class_key *key)
 {
-	struct tvec_base *base = __raw_get_cpu_var(tvec_bases);
+	struct tvec_base *base = __this_cpu_read(tvec_bases);
 
 	timer->entry.next = NULL;
 	timer->base = (void *)((unsigned long)base | flags);

[gcv v3 05/35] time: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/hrtimer.c
===================================================================
--- linux.orig/kernel/hrtimer.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/hrtimer.c	2013-08-26 14:21:24.540227691 -0500
@@ -597,7 +597,7 @@ hrtimer_force_reprogram(struct hrtimer_c
 static int hrtimer_reprogram(struct hrtimer *timer,
 			     struct hrtimer_clock_base *base)
 {
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
 	int res;
 
@@ -680,7 +680,7 @@ static inline ktime_t hrtimer_update_bas
  */
 static void retrigger_next_event(void *arg)
 {
-	struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
 
 	if (!hrtimer_hres_active())
 		return;
@@ -954,7 +954,7 @@ remove_hrtimer(struct hrtimer *timer, st
 		 */
 		debug_deactivate(timer);
 		timer_stats_hrtimer_clear_start_info(timer);
-		reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
+		reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
 		/*
 		 * We must preserve the CALLBACK state flag here,
 		 * otherwise we could move the timer base in
@@ -1009,7 +1009,7 @@ int __hrtimer_start_range_ns(struct hrti
 	 *
 	 * XXX send_remote_softirq() ?
 	 */
-	if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases)
+	if (leftmost && new_base->cpu_base == this_cpu_ptr(&hrtimer_bases)
 		&& hrtimer_enqueue_reprogram(timer, new_base)) {
 		if (wakeup) {
 			/*
@@ -1142,7 +1142,7 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining)
  */
 ktime_t hrtimer_get_next_event(void)
 {
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base = cpu_base->clock_base;
 	ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
 	unsigned long flags;
@@ -1183,7 +1183,7 @@ static void __hrtimer_init(struct hrtime
 
 	memset(timer, 0, sizeof(struct hrtimer));
 
-	cpu_base = &__raw_get_cpu_var(hrtimer_bases);
+	cpu_base = __this_cpu_ptr(&hrtimer_bases);
 
 	if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
 		clock_id = CLOCK_MONOTONIC;
@@ -1226,7 +1226,7 @@ int hrtimer_get_res(const clockid_t whic
 	struct hrtimer_cpu_base *cpu_base;
 	int base = hrtimer_clockid_to_base(which_clock);
 
-	cpu_base = &__raw_get_cpu_var(hrtimer_bases);
+	cpu_base = __this_cpu_ptr(&hrtimer_bases);
 	*tp = ktime_to_timespec(cpu_base->clock_base[base].resolution);
 
 	return 0;
@@ -1281,7 +1281,7 @@ static void __run_hrtimer(struct hrtimer
  */
 void hrtimer_interrupt(struct clock_event_device *dev)
 {
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	ktime_t expires_next, now, entry_time, delta;
 	int i, retries = 0;
 
@@ -1415,7 +1415,7 @@ static void __hrtimer_peek_ahead_timers(
 	if (!hrtimer_hres_active())
 		return;
 
-	td = &__get_cpu_var(tick_cpu_device);
+	td = this_cpu_ptr(&tick_cpu_device);
 	if (td && td->evtdev)
 		hrtimer_interrupt(td->evtdev);
 }
@@ -1479,7 +1479,7 @@ void hrtimer_run_pending(void)
 void hrtimer_run_queues(void)
 {
 	struct timerqueue_node *node;
-	struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
+	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
 	struct hrtimer_clock_base *base;
 	int index, gettime = 1;
 
@@ -1717,7 +1717,7 @@ static void migrate_hrtimers(int scpu)
 
 	local_irq_disable();
 	old_base = &per_cpu(hrtimer_bases, scpu);
-	new_base = &__get_cpu_var(hrtimer_bases);
+	new_base = this_cpu_ptr(&hrtimer_bases);
 	/*
 	 * The caller is globally serialized and nobody else
 	 * takes two locks at once, deadlock is not possible.
Index: linux/kernel/irq_work.c
===================================================================
--- linux.orig/kernel/irq_work.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/irq_work.c	2013-08-26 14:21:24.540227691 -0500
@@ -70,7 +70,7 @@ void irq_work_queue(struct irq_work *wor
 	/* Queue the entry and raise the IPI if needed. */
 	preempt_disable();
 
-	llist_add(&work->llnode, &__get_cpu_var(irq_work_list));
+	llist_add(&work->llnode, this_cpu_ptr(&irq_work_list));
 
 	/*
 	 * If the work is not "lazy" or the tick is stopped, raise the irq
@@ -90,7 +90,7 @@ bool irq_work_needs_cpu(void)
 {
 	struct llist_head *this_list;
 
-	this_list = &__get_cpu_var(irq_work_list);
+	this_list = this_cpu_ptr(&irq_work_list);
 	if (llist_empty(this_list))
 		return false;
 
@@ -115,7 +115,7 @@ static void __irq_work_run(void)
 	__this_cpu_write(irq_work_raised, 0);
 	barrier();
 
-	this_list = &__get_cpu_var(irq_work_list);
+	this_list = this_cpu_ptr(&irq_work_list);
 	if (llist_empty(this_list))
 		return;
 
Index: linux/kernel/sched/clock.c
===================================================================
--- linux.orig/kernel/sched/clock.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/sched/clock.c	2013-08-26 14:21:24.540227691 -0500
@@ -94,7 +94,7 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(str
 
 static inline struct sched_clock_data *this_scd(void)
 {
-	return &__get_cpu_var(sched_clock_data);
+	return this_cpu_ptr(&sched_clock_data);
 }
 
 static inline struct sched_clock_data *cpu_sdc(int cpu)
Index: linux/kernel/softirq.c
===================================================================
--- linux.orig/kernel/softirq.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/softirq.c	2013-08-26 14:21:24.540227691 -0500
@@ -466,7 +466,7 @@ static void tasklet_action(struct softir
 	local_irq_disable();
 	list = __this_cpu_read(tasklet_vec.head);
 	__this_cpu_write(tasklet_vec.head, NULL);
-	__this_cpu_write(tasklet_vec.tail, &__get_cpu_var(tasklet_vec).head);
+	__this_cpu_write(tasklet_vec.tail, this_cpu_ptr(&tasklet_vec.head));
 	local_irq_enable();
 
 	while (list) {
@@ -501,7 +501,7 @@ static void tasklet_hi_action(struct sof
 	local_irq_disable();
 	list = __this_cpu_read(tasklet_hi_vec.head);
 	__this_cpu_write(tasklet_hi_vec.head, NULL);
-	__this_cpu_write(tasklet_hi_vec.tail, &__get_cpu_var(tasklet_hi_vec).head);
+	__this_cpu_write(tasklet_hi_vec.tail, this_cpu_ptr(&tasklet_hi_vec.head));
 	local_irq_enable();
 
 	while (list) {
@@ -618,7 +618,7 @@ EXPORT_PER_CPU_SYMBOL(softirq_work_list)
 
 static void __local_trigger(struct call_single_data *cp, int softirq)
 {
-	struct list_head *head = &__get_cpu_var(softirq_work_list[softirq]);
+	struct list_head *head = this_cpu_ptr(&softirq_work_list[softirq]);
 
 	list_add_tail(&cp->list, head);
 
@@ -718,7 +718,7 @@ static int remote_softirq_cpu_notify(str
 			if (list_empty(head))
 				continue;
 
-			local_head = &__get_cpu_var(softirq_work_list[i]);
+			local_head = this_cpu_ptr(&softirq_work_list[i]);
 			list_splice_init(head, local_head);
 			raise_softirq_irqoff(i);
 		}
Index: linux/kernel/time/tick-common.c
===================================================================
--- linux.orig/kernel/time/tick-common.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/time/tick-common.c	2013-08-26 14:21:24.544227649 -0500
@@ -208,7 +208,7 @@ static void tick_setup_device(struct tic
 
 void tick_install_replacement(struct clock_event_device *newdev)
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 	int cpu = smp_processor_id();
 
 	clockevents_exchange_device(td->evtdev, newdev);
@@ -358,14 +358,14 @@ void tick_shutdown(unsigned int *cpup)
 
 void tick_suspend(void)
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 
 	clockevents_shutdown(td->evtdev);
 }
 
 void tick_resume(void)
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 	int broadcast = tick_resume_broadcast();
 
 	clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
Index: linux/kernel/time/tick-oneshot.c
===================================================================
--- linux.orig/kernel/time/tick-oneshot.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/time/tick-oneshot.c	2013-08-26 14:21:24.544227649 -0500
@@ -59,7 +59,7 @@ void tick_setup_oneshot(struct clock_eve
  */
 int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
 {
-	struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+	struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
 	struct clock_event_device *dev = td->evtdev;
 
 	if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
Index: linux/kernel/time/tick-sched.c
===================================================================
--- linux.orig/kernel/time/tick-sched.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/time/tick-sched.c	2013-08-26 14:21:24.540227691 -0500
@@ -199,7 +199,7 @@ static void tick_nohz_restart_sched_tick
  */
 void tick_nohz_full_check(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (tick_nohz_full_cpu(smp_processor_id())) {
 		if (ts->tick_stopped && !is_idle_task(current)) {
@@ -225,7 +225,7 @@ static DEFINE_PER_CPU(struct irq_work, n
 void tick_nohz_full_kick(void)
 {
 	if (tick_nohz_full_cpu(smp_processor_id()))
-		irq_work_queue(&__get_cpu_var(nohz_full_kick_work));
+		irq_work_queue(this_cpu_ptr(&nohz_full_kick_work));
 }
 
 static void nohz_full_kick_ipi(void *info)
@@ -536,7 +536,7 @@ static ktime_t tick_nohz_stop_sched_tick
 	unsigned long seq, last_jiffies, next_jiffies, delta_jiffies;
 	ktime_t last_update, expires, ret = { .tv64 = 0 };
 	unsigned long rcu_delta_jiffies;
-	struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
+	struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
 	u64 time_delta;
 
 	/* Read jiffies and the time when jiffies were updated last */
@@ -801,7 +801,7 @@ void tick_nohz_idle_enter(void)
 
 	local_irq_disable();
 
-	ts = &__get_cpu_var(tick_cpu_sched);
+	ts = this_cpu_ptr(&tick_cpu_sched);
 	/*
 	 * set ts->inidle unconditionally. even if the system did not
 	 * switch to nohz mode the cpu frequency governers rely on the
@@ -824,7 +824,7 @@ EXPORT_SYMBOL_GPL(tick_nohz_idle_enter);
  */
 void tick_nohz_irq_exit(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (ts->inidle)
 		__tick_nohz_idle_enter(ts);
@@ -839,7 +839,7 @@ void tick_nohz_irq_exit(void)
  */
 ktime_t tick_nohz_get_sleep_length(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	return ts->sleep_length;
 }
@@ -953,7 +953,7 @@ static int tick_nohz_reprogram(struct ti
  */
 static void tick_nohz_handler(struct clock_event_device *dev)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 	struct pt_regs *regs = get_irq_regs();
 	ktime_t now = ktime_get();
 
@@ -973,7 +973,7 @@ static void tick_nohz_handler(struct clo
  */
 static void tick_nohz_switch_to_nohz(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 	ktime_t next;
 
 	if (!tick_nohz_enabled)
@@ -1111,7 +1111,7 @@ early_param("skew_tick", skew_tick);
  */
 void tick_setup_sched_timer(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 	ktime_t now = ktime_get();
 
 	/*
@@ -1178,7 +1178,7 @@ void tick_clock_notify(void)
  */
 void tick_oneshot_notify(void)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	set_bit(0, &ts->check_clocks);
 }
@@ -1193,7 +1193,7 @@ void tick_oneshot_notify(void)
  */
 int tick_check_oneshot_change(int allow_nohz)
 {
-	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
+	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
 
 	if (!test_and_clear_bit(0, &ts->check_clocks))
 		return 0;
Index: linux/kernel/timer.c
===================================================================
--- linux.orig/kernel/timer.c	2013-08-26 14:19:14.000000000 -0500
+++ linux/kernel/timer.c	2013-08-26 14:21:24.544227649 -0500
@@ -621,7 +621,7 @@ static inline void debug_assert_init(str
 static void do_init_timer(struct timer_list *timer, unsigned int flags,
 			  const char *name, struct lock_class_key *key)
 {
-	struct tvec_base *base = __raw_get_cpu_var(tvec_bases);
+	struct tvec_base *base = __this_cpu_read(tvec_bases);
 
 	timer->entry.next = NULL;
 	timer->base = (void *)((unsigned long)base | flags);

[gcv v3 17/35] drivers/net/ethernet/tile: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/net/ethernet/tile/tilegx.c
===================================================================
--- linux.orig/drivers/net/ethernet/tile/tilegx.c	2013-08-27 14:39:22.471612150 -0500
+++ linux/drivers/net/ethernet/tile/tilegx.c	2013-08-27 14:39:22.463612231 -0500
@@ -368,7 +368,7 @@ static void tile_net_pop_all_buffers(int
 /* Provide linux buffers to mPIPE. */
 static void tile_net_provide_needed_buffers(void)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 
 	while (info->num_needed_small_buffers != 0) {
 		if (!tile_net_provide_buffer(true))
@@ -407,7 +407,7 @@ static inline bool filter_packet(struct
 static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb,
 				 gxio_mpipe_idesc_t *idesc, unsigned long len)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct tile_net_priv *priv = netdev_priv(dev);
 
 	/* Encode the actual packet length. */
@@ -435,7 +435,7 @@ static void tile_net_receive_skb(struct
 /* Handle a packet.  Return true if "processed", false if "filtered". */
 static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct net_device *dev = tile_net_devs_for_channel[idesc->channel];
 	uint8_t l2_offset;
 	void *va;
@@ -498,7 +498,7 @@ static bool tile_net_handle_packet(gxio_
  */
 static int tile_net_poll(struct napi_struct *napi, int budget)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	unsigned int work = 0;
 	gxio_mpipe_idesc_t *idesc;
 	int i, n;
@@ -536,7 +536,7 @@ done:
 /* Handle an ingress interrupt on the current cpu. */
 static irqreturn_t tile_net_handle_ingress_irq(int irq, void *unused)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	napi_schedule(&info->napi);
 	return IRQ_HANDLED;
 }
@@ -597,7 +597,7 @@ static enum hrtimer_restart tile_net_han
 /* Make sure the egress timer is scheduled. */
 static void tile_net_schedule_egress_timer(void)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 
 	if (!info->egress_timer_scheduled) {
 		hrtimer_start(&info->egress_timer,
@@ -614,7 +614,7 @@ static void tile_net_schedule_egress_tim
  */
 static enum hrtimer_restart tile_net_handle_egress_timer(struct hrtimer *t)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	unsigned long irqflags;
 	bool pending = false;
 	int i;
@@ -649,7 +649,7 @@ static enum hrtimer_restart tile_net_han
  */
 static void tile_net_update_cpu(void *arg)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct net_device *dev = arg;
 
 	if (!info->has_iqueue)
@@ -1572,7 +1572,7 @@ static void tso_egress(struct net_device
  */
 static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct tile_net_priv *priv = netdev_priv(dev);
 	int channel = priv->echannel;
 	struct tile_net_egress *egress = &egress_for_echannel[channel];
@@ -1638,7 +1638,7 @@ static unsigned int tile_net_tx_frags(st
 /* Help the kernel transmit a packet. */
 static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct tile_net_priv *priv = netdev_priv(dev);
 	struct tile_net_egress *egress = &egress_for_echannel[priv->echannel];
 	gxio_mpipe_equeue_t *equeue = egress->equeue;
@@ -1869,7 +1869,7 @@ static void tile_net_dev_init(const char
 /* Per-cpu module initialization. */
 static void tile_net_init_module_percpu(void *unused)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	int my_cpu = smp_processor_id();
 
 	info->has_iqueue = false;
Index: linux/drivers/net/ethernet/tile/tilepro.c
===================================================================
--- linux.orig/drivers/net/ethernet/tile/tilepro.c	2013-08-27 14:39:22.471612150 -0500
+++ linux/drivers/net/ethernet/tile/tilepro.c	2013-08-27 14:39:22.463612231 -0500
@@ -1078,13 +1078,13 @@ static void tile_net_register(void *dev_
 	PDEBUG("tile_net_register(queue_id %d)\n", queue_id);
 
 	if (!strcmp(dev->name, "xgbe0"))
-		info = &__get_cpu_var(hv_xgbe0);
+		info = this_cpu_ptr(&hv_xgbe0);
 	else if (!strcmp(dev->name, "xgbe1"))
-		info = &__get_cpu_var(hv_xgbe1);
+		info = this_cpu_ptr(&hv_xgbe1);
 	else if (!strcmp(dev->name, "gbe0"))
-		info = &__get_cpu_var(hv_gbe0);
+		info = this_cpu_ptr(&hv_gbe0);
 	else if (!strcmp(dev->name, "gbe1"))
-		info = &__get_cpu_var(hv_gbe1);
+		info = this_cpu_ptr(&hv_gbe1);
 	else
 		BUG();
 

[gcv v3 17/35] drivers/net/ethernet/tile: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/net/ethernet/tile/tilegx.c
===================================================================
--- linux.orig/drivers/net/ethernet/tile/tilegx.c	2013-08-27 14:39:22.471612150 -0500
+++ linux/drivers/net/ethernet/tile/tilegx.c	2013-08-27 14:39:22.463612231 -0500
@@ -368,7 +368,7 @@ static void tile_net_pop_all_buffers(int
 /* Provide linux buffers to mPIPE. */
 static void tile_net_provide_needed_buffers(void)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 
 	while (info->num_needed_small_buffers != 0) {
 		if (!tile_net_provide_buffer(true))
@@ -407,7 +407,7 @@ static inline bool filter_packet(struct
 static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb,
 				 gxio_mpipe_idesc_t *idesc, unsigned long len)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct tile_net_priv *priv = netdev_priv(dev);
 
 	/* Encode the actual packet length. */
@@ -435,7 +435,7 @@ static void tile_net_receive_skb(struct
 /* Handle a packet.  Return true if "processed", false if "filtered". */
 static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct net_device *dev = tile_net_devs_for_channel[idesc->channel];
 	uint8_t l2_offset;
 	void *va;
@@ -498,7 +498,7 @@ static bool tile_net_handle_packet(gxio_
  */
 static int tile_net_poll(struct napi_struct *napi, int budget)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	unsigned int work = 0;
 	gxio_mpipe_idesc_t *idesc;
 	int i, n;
@@ -536,7 +536,7 @@ done:
 /* Handle an ingress interrupt on the current cpu. */
 static irqreturn_t tile_net_handle_ingress_irq(int irq, void *unused)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	napi_schedule(&info->napi);
 	return IRQ_HANDLED;
 }
@@ -597,7 +597,7 @@ static enum hrtimer_restart tile_net_han
 /* Make sure the egress timer is scheduled. */
 static void tile_net_schedule_egress_timer(void)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 
 	if (!info->egress_timer_scheduled) {
 		hrtimer_start(&info->egress_timer,
@@ -614,7 +614,7 @@ static void tile_net_schedule_egress_tim
  */
 static enum hrtimer_restart tile_net_handle_egress_timer(struct hrtimer *t)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	unsigned long irqflags;
 	bool pending = false;
 	int i;
@@ -649,7 +649,7 @@ static enum hrtimer_restart tile_net_han
  */
 static void tile_net_update_cpu(void *arg)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct net_device *dev = arg;
 
 	if (!info->has_iqueue)
@@ -1572,7 +1572,7 @@ static void tso_egress(struct net_device
  */
 static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct tile_net_priv *priv = netdev_priv(dev);
 	int channel = priv->echannel;
 	struct tile_net_egress *egress = &egress_for_echannel[channel];
@@ -1638,7 +1638,7 @@ static unsigned int tile_net_tx_frags(st
 /* Help the kernel transmit a packet. */
 static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	struct tile_net_priv *priv = netdev_priv(dev);
 	struct tile_net_egress *egress = &egress_for_echannel[priv->echannel];
 	gxio_mpipe_equeue_t *equeue = egress->equeue;
@@ -1869,7 +1869,7 @@ static void tile_net_dev_init(const char
 /* Per-cpu module initialization. */
 static void tile_net_init_module_percpu(void *unused)
 {
-	struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
+	struct tile_net_info *info = this_cpu_ptr(&per_cpu_info);
 	int my_cpu = smp_processor_id();
 
 	info->has_iqueue = false;
Index: linux/drivers/net/ethernet/tile/tilepro.c
===================================================================
--- linux.orig/drivers/net/ethernet/tile/tilepro.c	2013-08-27 14:39:22.471612150 -0500
+++ linux/drivers/net/ethernet/tile/tilepro.c	2013-08-27 14:39:22.463612231 -0500
@@ -1078,13 +1078,13 @@ static void tile_net_register(void *dev_
 	PDEBUG("tile_net_register(queue_id %d)\n", queue_id);
 
 	if (!strcmp(dev->name, "xgbe0"))
-		info = &__get_cpu_var(hv_xgbe0);
+		info = this_cpu_ptr(&hv_xgbe0);
 	else if (!strcmp(dev->name, "xgbe1"))
-		info = &__get_cpu_var(hv_xgbe1);
+		info = this_cpu_ptr(&hv_xgbe1);
 	else if (!strcmp(dev->name, "gbe0"))
-		info = &__get_cpu_var(hv_gbe0);
+		info = this_cpu_ptr(&hv_gbe0);
 	else if (!strcmp(dev->name, "gbe1"))
-		info = &__get_cpu_var(hv_gbe1);
+		info = this_cpu_ptr(&hv_gbe1);
 	else
 		BUG();
 

[gcv v3 08/35] tracing: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/linux/kprobes.h
===================================================================
--- linux.orig/include/linux/kprobes.h	2013-08-26 14:25:53.000000000 -0500
+++ linux/include/linux/kprobes.h	2013-08-26 14:26:29.460993659 -0500
@@ -329,7 +329,7 @@ static inline void reset_current_kprobe(
 
 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
 {
-	return (&__get_cpu_var(kprobe_ctlblk));
+	return this_cpu_ptr(&kprobe_ctlblk);
 }
 
 int register_kprobe(struct kprobe *p);
Index: linux/kernel/trace/ftrace.c
===================================================================
--- linux.orig/kernel/trace/ftrace.c	2013-08-26 14:25:53.000000000 -0500
+++ linux/kernel/trace/ftrace.c	2013-08-26 14:26:29.460993659 -0500
@@ -870,7 +870,7 @@ function_profile_call(unsigned long ip,
 
 	local_irq_save(flags);
 
-	stat = &__get_cpu_var(ftrace_profile_stats);
+	stat = this_cpu_ptr(&ftrace_profile_stats);
 	if (!stat->hash || !ftrace_profile_enabled)
 		goto out;
 
@@ -901,7 +901,7 @@ static void profile_graph_return(struct
 	unsigned long flags;
 
 	local_irq_save(flags);
-	stat = &__get_cpu_var(ftrace_profile_stats);
+	stat = this_cpu_ptr(&ftrace_profile_stats);
 	if (!stat->hash || !ftrace_profile_enabled)
 		goto out;
 
Index: linux/kernel/trace/trace.c
===================================================================
--- linux.orig/kernel/trace/trace.c	2013-08-26 14:25:53.000000000 -0500
+++ linux/kernel/trace/trace.c	2013-08-26 14:26:29.464993617 -0500
@@ -1676,7 +1676,7 @@ static void __ftrace_trace_stack(struct
 	 */
 	barrier();
 	if (use_stack == 1) {
-		trace.entries		= &__get_cpu_var(ftrace_stack).calls[0];
+		trace.entries		= this_cpu_ptr(ftrace_stack.calls);
 		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;
 
 		if (regs)

[gcv v3 08/35] tracing: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/linux/kprobes.h
===================================================================
--- linux.orig/include/linux/kprobes.h	2013-08-26 14:25:53.000000000 -0500
+++ linux/include/linux/kprobes.h	2013-08-26 14:26:29.460993659 -0500
@@ -329,7 +329,7 @@ static inline void reset_current_kprobe(
 
 static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
 {
-	return (&__get_cpu_var(kprobe_ctlblk));
+	return this_cpu_ptr(&kprobe_ctlblk);
 }
 
 int register_kprobe(struct kprobe *p);
Index: linux/kernel/trace/ftrace.c
===================================================================
--- linux.orig/kernel/trace/ftrace.c	2013-08-26 14:25:53.000000000 -0500
+++ linux/kernel/trace/ftrace.c	2013-08-26 14:26:29.460993659 -0500
@@ -870,7 +870,7 @@ function_profile_call(unsigned long ip,
 
 	local_irq_save(flags);
 
-	stat = &__get_cpu_var(ftrace_profile_stats);
+	stat = this_cpu_ptr(&ftrace_profile_stats);
 	if (!stat->hash || !ftrace_profile_enabled)
 		goto out;
 
@@ -901,7 +901,7 @@ static void profile_graph_return(struct
 	unsigned long flags;
 
 	local_irq_save(flags);
-	stat = &__get_cpu_var(ftrace_profile_stats);
+	stat = this_cpu_ptr(&ftrace_profile_stats);
 	if (!stat->hash || !ftrace_profile_enabled)
 		goto out;
 
Index: linux/kernel/trace/trace.c
===================================================================
--- linux.orig/kernel/trace/trace.c	2013-08-26 14:25:53.000000000 -0500
+++ linux/kernel/trace/trace.c	2013-08-26 14:26:29.464993617 -0500
@@ -1676,7 +1676,7 @@ static void __ftrace_trace_stack(struct
 	 */
 	barrier();
 	if (use_stack == 1) {
-		trace.entries		= &__get_cpu_var(ftrace_stack).calls[0];
+		trace.entries		= this_cpu_ptr(ftrace_stack.calls);
 		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;
 
 		if (regs)

Re: [gcv v3 08/35] tracing: Replace __get_cpu_var uses

[Steven Rostedt]

On Wed, 28 Aug 2013 19:48:16 +0000

> Index: linux/kernel/trace/trace.c
> ===================================================================
> --- linux.orig/kernel/trace/trace.c	2013-08-26 14:25:53.000000000 -0500
> +++ linux/kernel/trace/trace.c	2013-08-26 14:26:29.464993617 -0500
> @@ -1676,7 +1676,7 @@ static void __ftrace_trace_stack(struct
>  	 */
>  	barrier();
>  	if (use_stack == 1) {
> -		trace.entries		= &__get_cpu_var(ftrace_stack).calls[0];
> +		trace.entries		= this_cpu_ptr(ftrace_stack.calls);
>  		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;
>  
>  		if (regs)


This patch fails to build:

kernel/trace/trace.c: In function ‘__ftrace_trace_stack’:
kernel/trace/trace.c:1679:20: error: cast specifies array type

-- Steve

Re: [gcv v3 08/35] tracing: Replace __get_cpu_var uses

[Christoph Lameter]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 918 bytes --]

On Thu, 29 Aug 2013, Steven Rostedt wrote:

> On Wed, 28 Aug 2013 19:48:16 +0000
>
> > Index: linux/kernel/trace/trace.c
> > ===================================================================
> > --- linux.orig/kernel/trace/trace.c	2013-08-26 14:25:53.000000000 -0500
> > +++ linux/kernel/trace/trace.c	2013-08-26 14:26:29.464993617 -0500
> > @@ -1676,7 +1676,7 @@ static void __ftrace_trace_stack(struct
> >  	 */
> >  	barrier();
> >  	if (use_stack == 1) {
> > -		trace.entries		= &__get_cpu_var(ftrace_stack).calls[0];
> > +		trace.entries		= this_cpu_ptr(ftrace_stack.calls);
> >  		trace.max_entries	= FTRACE_STACK_MAX_ENTRIES;
> >
> >  		if (regs)
>
>
> This patch fails to build:
>
> kernel/trace/trace.c: In function ‘__ftrace_trace_stack’:
> kernel/trace/trace.c:1679:20: error: cast specifies array type

That is because you did not apply the first patch of this series that
fixes a bug in the macros.

[gcv v3 13/35] kernel misc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/printk/printk.c
===================================================================
--- linux.orig/kernel/printk/printk.c	2013-08-26 14:30:25.846490787 -0500
+++ linux/kernel/printk/printk.c	2013-08-26 14:30:25.846490787 -0500
@@ -2441,7 +2441,7 @@ static void wake_up_klogd_work_func(stru
 	int pending = __this_cpu_xchg(printk_pending, 0);
 
 	if (pending & PRINTK_PENDING_SCHED) {
-		char *buf = __get_cpu_var(printk_sched_buf);
+		char *buf = this_cpu_ptr(printk_sched_buf);
 		printk(KERN_WARNING "[sched_delayed] %s", buf);
 	}
 
@@ -2459,7 +2459,7 @@ void wake_up_klogd(void)
 	preempt_disable();
 	if (waitqueue_active(&log_wait)) {
 		this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
-		irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+		irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
 	}
 	preempt_enable();
 }
@@ -2472,14 +2472,14 @@ int printk_sched(const char *fmt, ...)
 	int r;
 
 	local_irq_save(flags);
-	buf = __get_cpu_var(printk_sched_buf);
+	buf = this_cpu_ptr(printk_sched_buf);
 
 	va_start(args, fmt);
 	r = vsnprintf(buf, PRINTK_BUF_SIZE, fmt, args);
 	va_end(args);
 
 	__this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
-	irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+	irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
 	local_irq_restore(flags);
 
 	return r;
Index: linux/kernel/smp.c
===================================================================
--- linux.orig/kernel/smp.c	2013-08-26 14:30:25.846490787 -0500
+++ linux/kernel/smp.c	2013-08-26 14:30:25.846490787 -0500
@@ -172,7 +172,7 @@ void generic_exec_single(int cpu, struct
  */
 void generic_smp_call_function_single_interrupt(void)
 {
-	struct call_single_queue *q = &__get_cpu_var(call_single_queue);
+	struct call_single_queue *q = this_cpu_ptr(&call_single_queue);
 	LIST_HEAD(list);
 
 	/*
@@ -252,7 +252,7 @@ int smp_call_function_single(int cpu, sm
 			struct call_single_data *csd = &d;
 
 			if (!wait)
-				csd = &__get_cpu_var(csd_data);
+				csd = this_cpu_ptr(&csd_data);
 
 			csd_lock(csd);
 
@@ -401,7 +401,7 @@ void smp_call_function_many(const struct
 		return;
 	}
 
-	cfd = &__get_cpu_var(cfd_data);
+	cfd = this_cpu_ptr(&cfd_data);
 
 	cpumask_and(cfd->cpumask, mask, cpu_online_mask);
 	cpumask_clear_cpu(this_cpu, cfd->cpumask);

[gcv v3 13/35] kernel misc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/printk/printk.c
===================================================================
--- linux.orig/kernel/printk/printk.c	2013-08-26 14:30:25.846490787 -0500
+++ linux/kernel/printk/printk.c	2013-08-26 14:30:25.846490787 -0500
@@ -2441,7 +2441,7 @@ static void wake_up_klogd_work_func(stru
 	int pending = __this_cpu_xchg(printk_pending, 0);
 
 	if (pending & PRINTK_PENDING_SCHED) {
-		char *buf = __get_cpu_var(printk_sched_buf);
+		char *buf = this_cpu_ptr(printk_sched_buf);
 		printk(KERN_WARNING "[sched_delayed] %s", buf);
 	}
 
@@ -2459,7 +2459,7 @@ void wake_up_klogd(void)
 	preempt_disable();
 	if (waitqueue_active(&log_wait)) {
 		this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
-		irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+		irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
 	}
 	preempt_enable();
 }
@@ -2472,14 +2472,14 @@ int printk_sched(const char *fmt, ...)
 	int r;
 
 	local_irq_save(flags);
-	buf = __get_cpu_var(printk_sched_buf);
+	buf = this_cpu_ptr(printk_sched_buf);
 
 	va_start(args, fmt);
 	r = vsnprintf(buf, PRINTK_BUF_SIZE, fmt, args);
 	va_end(args);
 
 	__this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
-	irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+	irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
 	local_irq_restore(flags);
 
 	return r;
Index: linux/kernel/smp.c
===================================================================
--- linux.orig/kernel/smp.c	2013-08-26 14:30:25.846490787 -0500
+++ linux/kernel/smp.c	2013-08-26 14:30:25.846490787 -0500
@@ -172,7 +172,7 @@ void generic_exec_single(int cpu, struct
  */
 void generic_smp_call_function_single_interrupt(void)
 {
-	struct call_single_queue *q = &__get_cpu_var(call_single_queue);
+	struct call_single_queue *q = this_cpu_ptr(&call_single_queue);
 	LIST_HEAD(list);
 
 	/*
@@ -252,7 +252,7 @@ int smp_call_function_single(int cpu, sm
 			struct call_single_data *csd = &d;
 
 			if (!wait)
-				csd = &__get_cpu_var(csd_data);
+				csd = this_cpu_ptr(&csd_data);
 
 			csd_lock(csd);
 
@@ -401,7 +401,7 @@ void smp_call_function_many(const struct
 		return;
 	}
 
-	cfd = &__get_cpu_var(cfd_data);
+	cfd = this_cpu_ptr(&cfd_data);
 
 	cpumask_and(cfd->cpumask, mask, cpu_online_mask);
 	cpumask_clear_cpu(this_cpu, cfd->cpumask);

[gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/rcutree.c
===================================================================
--- linux.orig/kernel/rcutree.c	2013-08-26 14:27:35.000000000 -0500
+++ linux/kernel/rcutree.c	2013-08-26 14:28:13.959886770 -0500
@@ -383,7 +383,7 @@ static void rcu_eqs_enter(bool user)
 	long long oldval;
 	struct rcu_dynticks *rdtp;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0);
 	if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE)
@@ -443,7 +443,7 @@ void rcu_user_enter_after_irq(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	/* Ensure this irq is interrupting a non-idle RCU state.  */
 	WARN_ON_ONCE(!(rdtp->dynticks_nesting & DYNTICK_TASK_MASK));
 	rdtp->dynticks_nesting = 1;
@@ -474,7 +474,7 @@ void rcu_irq_exit(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting--;
 	WARN_ON_ONCE(rdtp->dynticks_nesting < 0);
@@ -523,7 +523,7 @@ static void rcu_eqs_exit(bool user)
 	struct rcu_dynticks *rdtp;
 	long long oldval;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE(oldval < 0);
 	if (oldval & DYNTICK_TASK_NEST_MASK)
@@ -581,7 +581,7 @@ void rcu_user_exit_after_irq(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	/* Ensure we are interrupting an RCU idle mode. */
 	WARN_ON_ONCE(rdtp->dynticks_nesting & DYNTICK_TASK_NEST_MASK);
 	rdtp->dynticks_nesting += DYNTICK_TASK_EXIT_IDLE;
@@ -615,7 +615,7 @@ void rcu_irq_enter(void)
 	long long oldval;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting++;
 	WARN_ON_ONCE(rdtp->dynticks_nesting == 0);
@@ -635,7 +635,7 @@ void rcu_irq_enter(void)
  */
 void rcu_nmi_enter(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 &&
 	    (atomic_read(&rdtp->dynticks) & 0x1))
@@ -657,7 +657,7 @@ void rcu_nmi_enter(void)
  */
 void rcu_nmi_exit(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 ||
 	    --rdtp->dynticks_nmi_nesting != 0)
@@ -680,7 +680,7 @@ int rcu_is_cpu_idle(void)
 	int ret;
 
 	preempt_disable();
-	ret = (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+	ret = (atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1) == 0;
 	preempt_enable();
 	return ret;
 }
@@ -718,7 +718,7 @@ bool rcu_lockdep_current_cpu_online(void
 	if (in_nmi())
 		return 1;
 	preempt_disable();
-	rdp = &__get_cpu_var(rcu_sched_data);
+	rdp = this_cpu_ptr(&rcu_sched_data);
 	rnp = rdp->mynode;
 	ret = (rdp->grpmask & rnp->qsmaskinit) ||
 	      !rcu_scheduler_fully_active;
@@ -738,7 +738,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cp
  */
 static int rcu_is_cpu_rrupt_from_idle(void)
 {
-	return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1;
+	return __this_cpu_read(rcu_dynticks.dynticks_nesting) <= 1;
 }
 
 /*
Index: linux/kernel/rcutree_plugin.h
===================================================================
--- linux.orig/kernel/rcutree_plugin.h	2013-08-26 14:27:35.000000000 -0500
+++ linux/kernel/rcutree_plugin.h	2013-08-26 14:28:13.963886728 -0500
@@ -662,7 +662,7 @@ static void rcu_preempt_check_callbacks(
 
 static void rcu_preempt_do_callbacks(void)
 {
-	rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
+	rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
 }
 
 #endif /* #ifdef CONFIG_RCU_BOOST */
@@ -1334,7 +1334,7 @@ static void invoke_rcu_callbacks_kthread
  */
 static bool rcu_is_callbacks_kthread(void)
 {
-	return __get_cpu_var(rcu_cpu_kthread_task) == current;
+	return __this_cpu_read(rcu_cpu_kthread_task) == current;
 }
 
 #define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000)
@@ -1384,8 +1384,8 @@ static int rcu_spawn_one_boost_kthread(s
 
 static void rcu_kthread_do_work(void)
 {
-	rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
-	rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
+	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
 	rcu_preempt_do_callbacks();
 }
 
@@ -1404,7 +1404,7 @@ static void rcu_cpu_kthread_park(unsigne
 
 static int rcu_cpu_kthread_should_run(unsigned int cpu)
 {
-	return __get_cpu_var(rcu_cpu_has_work);
+	return __this_cpu_read(rcu_cpu_has_work);
 }
 
 /*
@@ -1414,8 +1414,8 @@ static int rcu_cpu_kthread_should_run(un
  */
 static void rcu_cpu_kthread(unsigned int cpu)
 {
-	unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
-	char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
+	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
 	int spincnt;
 
 	for (spincnt = 0; spincnt < 10; spincnt++) {

[gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/kernel/rcutree.c
===================================================================
--- linux.orig/kernel/rcutree.c	2013-08-26 14:27:35.000000000 -0500
+++ linux/kernel/rcutree.c	2013-08-26 14:28:13.959886770 -0500
@@ -383,7 +383,7 @@ static void rcu_eqs_enter(bool user)
 	long long oldval;
 	struct rcu_dynticks *rdtp;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0);
 	if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE)
@@ -443,7 +443,7 @@ void rcu_user_enter_after_irq(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	/* Ensure this irq is interrupting a non-idle RCU state.  */
 	WARN_ON_ONCE(!(rdtp->dynticks_nesting & DYNTICK_TASK_MASK));
 	rdtp->dynticks_nesting = 1;
@@ -474,7 +474,7 @@ void rcu_irq_exit(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting--;
 	WARN_ON_ONCE(rdtp->dynticks_nesting < 0);
@@ -523,7 +523,7 @@ static void rcu_eqs_exit(bool user)
 	struct rcu_dynticks *rdtp;
 	long long oldval;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE(oldval < 0);
 	if (oldval & DYNTICK_TASK_NEST_MASK)
@@ -581,7 +581,7 @@ void rcu_user_exit_after_irq(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	/* Ensure we are interrupting an RCU idle mode. */
 	WARN_ON_ONCE(rdtp->dynticks_nesting & DYNTICK_TASK_NEST_MASK);
 	rdtp->dynticks_nesting += DYNTICK_TASK_EXIT_IDLE;
@@ -615,7 +615,7 @@ void rcu_irq_enter(void)
 	long long oldval;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting++;
 	WARN_ON_ONCE(rdtp->dynticks_nesting == 0);
@@ -635,7 +635,7 @@ void rcu_irq_enter(void)
  */
 void rcu_nmi_enter(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 &&
 	    (atomic_read(&rdtp->dynticks) & 0x1))
@@ -657,7 +657,7 @@ void rcu_nmi_enter(void)
  */
 void rcu_nmi_exit(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 ||
 	    --rdtp->dynticks_nmi_nesting != 0)
@@ -680,7 +680,7 @@ int rcu_is_cpu_idle(void)
 	int ret;
 
 	preempt_disable();
-	ret = (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+	ret = (atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1) == 0;
 	preempt_enable();
 	return ret;
 }
@@ -718,7 +718,7 @@ bool rcu_lockdep_current_cpu_online(void
 	if (in_nmi())
 		return 1;
 	preempt_disable();
-	rdp = &__get_cpu_var(rcu_sched_data);
+	rdp = this_cpu_ptr(&rcu_sched_data);
 	rnp = rdp->mynode;
 	ret = (rdp->grpmask & rnp->qsmaskinit) ||
 	      !rcu_scheduler_fully_active;
@@ -738,7 +738,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cp
  */
 static int rcu_is_cpu_rrupt_from_idle(void)
 {
-	return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1;
+	return __this_cpu_read(rcu_dynticks.dynticks_nesting) <= 1;
 }
 
 /*
Index: linux/kernel/rcutree_plugin.h
===================================================================
--- linux.orig/kernel/rcutree_plugin.h	2013-08-26 14:27:35.000000000 -0500
+++ linux/kernel/rcutree_plugin.h	2013-08-26 14:28:13.963886728 -0500
@@ -662,7 +662,7 @@ static void rcu_preempt_check_callbacks(
 
 static void rcu_preempt_do_callbacks(void)
 {
-	rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
+	rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
 }
 
 #endif /* #ifdef CONFIG_RCU_BOOST */
@@ -1334,7 +1334,7 @@ static void invoke_rcu_callbacks_kthread
  */
 static bool rcu_is_callbacks_kthread(void)
 {
-	return __get_cpu_var(rcu_cpu_kthread_task) == current;
+	return __this_cpu_read(rcu_cpu_kthread_task) == current;
 }
 
 #define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000)
@@ -1384,8 +1384,8 @@ static int rcu_spawn_one_boost_kthread(s
 
 static void rcu_kthread_do_work(void)
 {
-	rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
-	rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
+	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
 	rcu_preempt_do_callbacks();
 }
 
@@ -1404,7 +1404,7 @@ static void rcu_cpu_kthread_park(unsigne
 
 static int rcu_cpu_kthread_should_run(unsigned int cpu)
 {
-	return __get_cpu_var(rcu_cpu_has_work);
+	return __this_cpu_read(rcu_cpu_has_work);
 }
 
 /*
@@ -1414,8 +1414,8 @@ static int rcu_cpu_kthread_should_run(un
  */
 static void rcu_cpu_kthread(unsigned int cpu)
 {
-	unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
-	char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
+	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
 	int spincnt;
 
 	for (spincnt = 0; spincnt < 10; spincnt++) {

Re: [gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Paul E. McKenney]

On Wed, Aug 28, 2013 at 07:48:17PM +0000, Christoph Lameter wrote:
> __get_cpu_var() is used for multiple purposes in the kernel source. One of them is
> address calculation via the form &__get_cpu_var(x). This calculates the address for
> the instance of the percpu variable of the current processor based on an offset.
> 
> Other use cases are for storing and retrieving data from the current processors percpu area.
> __get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.
> 
> __get_cpu_var() is defined as :
> 
> 
> #define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
> 
> 
> 
> __get_cpu_var() always only does an address determination. However, store and retrieve operations
> could use a segment prefix (or global register on other platforms) to avoid the address calculation.
> 
> this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
> optimized assembly code to read and write per cpu variables.
> 
> 
> This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
> or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
> and less registers are used when code is generated.
> 
> At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.
> 
> The patchset includes passes over all arches as well. Once these operations are used throughout then
> specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
> f.e. using a global register that may be set to the per cpu base.
> 
> 
> 
> 
> Transformations done to __get_cpu_var()
> 
> 
> 1. Determine the address of the percpu instance of the current processor.
> 
> 	DEFINE_PER_CPU(int, y);
> 	int *x = &__get_cpu_var(y);
> 
>     Converts to
> 
> 	int *x = this_cpu_ptr(&y);
> 
> 
> 2. Same as #1 but this time an array structure is involved.
> 
> 	DEFINE_PER_CPU(int, y[20]);
> 	int *x = __get_cpu_var(y);
> 
>     Converts to
> 
> 	int *x = this_cpu_ptr(y);
> 
> 
> 3. Retrieve the content of the current processors instance of a per cpu variable.
> 
> 	DEFINE_PER_CPU(int, u);
> 	int x = __get_cpu_var(y)
> 
>    Converts to
> 
> 	int x = __this_cpu_read(y);
> 
> 
> 4. Retrieve the content of a percpu struct
> 
> 	DEFINE_PER_CPU(struct mystruct, y);
> 	struct mystruct x = __get_cpu_var(y);
> 
>    Converts to
> 
> 	memcpy(this_cpu_ptr(&x), y, sizeof(x));
> 
> 
> 5. Assignment to a per cpu variable
> 
> 	DEFINE_PER_CPU(int, y)
> 	__get_cpu_var(y) = x;
> 
>    Converts to
> 
> 	this_cpu_write(y, x);
> 
> 
> 6. Increment/Decrement etc of a per cpu variable
> 
> 	DEFINE_PER_CPU(int, y);
> 	__get_cpu_var(y)++
> 
>    Converts to
> 
> 	this_cpu_inc(y)
> 
> Signed-off-by: Christoph Lameter <cl@linux.com>

Queued for 3.13.  I had to rework for conflicts, please see below for
the update patch.

							Thanx, Paul

------------------------------------------------------------------------

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index a51985e..fccb6e8 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -400,7 +400,7 @@ static void rcu_eqs_enter(bool user)
 	long long oldval;
 	struct rcu_dynticks *rdtp;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0);
 	if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE)
@@ -428,7 +428,7 @@ void rcu_idle_enter(void)
 
 	local_irq_save(flags);
 	rcu_eqs_enter(false);
-	rcu_sysidle_enter(&__get_cpu_var(rcu_dynticks), 0);
+	rcu_sysidle_enter(this_cpu_ptr(&rcu_dynticks), 0);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_enter);
@@ -471,7 +471,7 @@ void rcu_irq_exit(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting--;
 	WARN_ON_ONCE(rdtp->dynticks_nesting < 0);
@@ -521,7 +521,7 @@ static void rcu_eqs_exit(bool user)
 	struct rcu_dynticks *rdtp;
 	long long oldval;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE(oldval < 0);
 	if (oldval & DYNTICK_TASK_NEST_MASK)
@@ -548,7 +548,7 @@ void rcu_idle_exit(void)
 
 	local_irq_save(flags);
 	rcu_eqs_exit(false);
-	rcu_sysidle_exit(&__get_cpu_var(rcu_dynticks), 0);
+	rcu_sysidle_exit(this_cpu_ptr(&rcu_dynticks), 0);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_exit);
@@ -592,7 +592,7 @@ void rcu_irq_enter(void)
 	long long oldval;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting++;
 	WARN_ON_ONCE(rdtp->dynticks_nesting == 0);
@@ -613,7 +613,7 @@ void rcu_irq_enter(void)
  */
 void rcu_nmi_enter(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 &&
 	    (atomic_read(&rdtp->dynticks) & 0x1))
@@ -635,7 +635,7 @@ void rcu_nmi_enter(void)
  */
 void rcu_nmi_exit(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 ||
 	    --rdtp->dynticks_nmi_nesting != 0)
@@ -658,7 +658,7 @@ int rcu_is_cpu_idle(void)
 	int ret;
 
 	preempt_disable();
-	ret = (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+	ret = (atomic_read(this_cpu_ptr(&rcu_dynticks).dynticks) & 0x1) == 0;
 	preempt_enable();
 	return ret;
 }
@@ -696,7 +696,7 @@ bool rcu_lockdep_current_cpu_online(void)
 	if (in_nmi())
 		return 1;
 	preempt_disable();
-	rdp = &__get_cpu_var(rcu_sched_data);
+	rdp = this_cpu_ptr(&rcu_sched_data);
 	rnp = rdp->mynode;
 	ret = (rdp->grpmask & rnp->qsmaskinit) ||
 	      !rcu_scheduler_fully_active;
@@ -716,7 +716,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cpu_online);
  */
 static int rcu_is_cpu_rrupt_from_idle(void)
 {
-	return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1;
+	return __this_cpu_read(rcu_dynticks.dynticks_nesting) <= 1;
 }
 
 /*
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 7661875..e90b9c8 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -660,7 +660,7 @@ static void rcu_preempt_check_callbacks(int cpu)
 
 static void rcu_preempt_do_callbacks(void)
 {
-	rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
+	rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
 }
 
 #endif /* #ifdef CONFIG_RCU_BOOST */
@@ -1332,7 +1332,7 @@ static void invoke_rcu_callbacks_kthread(void)
  */
 static bool rcu_is_callbacks_kthread(void)
 {
-	return __get_cpu_var(rcu_cpu_kthread_task) == current;
+	return __this_cpu_read(rcu_cpu_kthread_task) == current;
 }
 
 #define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000)
@@ -1382,8 +1382,8 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 
 static void rcu_kthread_do_work(void)
 {
-	rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
-	rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
+	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
 	rcu_preempt_do_callbacks();
 }
 
@@ -1402,7 +1402,7 @@ static void rcu_cpu_kthread_park(unsigned int cpu)
 
 static int rcu_cpu_kthread_should_run(unsigned int cpu)
 {
-	return __get_cpu_var(rcu_cpu_has_work);
+	return __this_cpu_read(rcu_cpu_has_work);
 }
 
 /*
@@ -1412,8 +1412,8 @@ static int rcu_cpu_kthread_should_run(unsigned int cpu)
  */
 static void rcu_cpu_kthread(unsigned int cpu)
 {
-	unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
-	char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
+	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
 	int spincnt;
 
 	for (spincnt = 0; spincnt < 10; spincnt++) {
@@ -1638,7 +1638,7 @@ static bool rcu_try_advance_all_cbs(void)
 {
 	bool cbs_ready = false;
 	struct rcu_data *rdp;
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 	struct rcu_node *rnp;
 	struct rcu_state *rsp;
 

Re: [gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Christoph Lameter]

On Sat, 31 Aug 2013, Paul E. McKenney wrote:

> Queued for 3.13.  I had to rework for conflicts, please see below for
> the update patch.

Looks fine to me. Can I drop the rcu patches from my patchset?

Re: [gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Christoph Lameter]

On Sat, 31 Aug 2013, Paul E. McKenney wrote:

> Queued for 3.13.  I had to rework for conflicts, please see below for
> the update patch.

Looks fine to me. Can I drop the rcu patches from my patchset?

Re: [gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Paul E. McKenney]

On Wed, Sep 04, 2013 at 02:19:59PM +0000, Christoph Lameter wrote:
> On Sat, 31 Aug 2013, Paul E. McKenney wrote:
> 
> > Queued for 3.13.  I had to rework for conflicts, please see below for
> > the update patch.
> 
> Looks fine to me. Can I drop the rcu patches from my patchset?

Yep, still queued for 3.13, and I even redid the change in
rcu_is_cpu_idle() to be the way you wanted it.  I wouldn't do that for
just anyone, you know!  ;-)

Current patch below.

							Thanx, Paul

------------------------------------------------------------------------

    rcu: Replace __get_cpu_var() uses
    
    __get_cpu_var() is used for multiple purposes in the kernel source. One
    of them is address calculation via the form &__get_cpu_var(x). This
    calculates the address for the instance of the percpu variable of the
    current processor based on an offset.
    
    Other use cases are for storing and retrieving data from the current
    processors percpu area.  __get_cpu_var() can be used as an lvalue when
    writing data or on the right side of an assignment.
    
    __get_cpu_var() is defined as :
    
    __get_cpu_var() always only does an address determination. However,
    store and retrieve operations could use a segment prefix (or global
    register on other platforms) to avoid the address calculation.
    
    this_cpu_write() and this_cpu_read() can directly take an offset into
    a percpu area and use optimized assembly code to read and write per
    cpu variables.
    
    This patch converts __get_cpu_var into either an explicit address
    calculation using this_cpu_ptr() or into a use of this_cpu operations
    that use the offset. Thereby address calcualtions are avoided and less
    registers are used when code is generated.
    
    At the end of the patchset all uses of __get_cpu_var have been removed
    so the macro is removed too.
    
    The patchset includes passes over all arches as well. Once these
    operations are used throughout then specialized macros can be defined in
    non -x86 arches as well in order to optimize per cpu access by f.e. using
    a global register that may be set to the per cpu base.
    
    Transformations done to __get_cpu_var()
    
    1. Determine the address of the percpu instance of the current processor.
    
    	DEFINE_PER_CPU(int, y);
    	int *x = &__get_cpu_var(y);
    
        Converts to
    
    	int *x = this_cpu_ptr(&y);
    
    2. Same as #1 but this time an array structure is involved.
    
    	DEFINE_PER_CPU(int, y[20]);
    	int *x = __get_cpu_var(y);
    
        Converts to
    
    	int *x = this_cpu_ptr(y);
    
    3. Retrieve the content of the current processors instance of a per cpu
       variable.
    
    	DEFINE_PER_CPU(int, u);
    	int x = __get_cpu_var(y)
    
       Converts to
    
    	int x = __this_cpu_read(y);
    
    4. Retrieve the content of a percpu struct
    
    	DEFINE_PER_CPU(struct mystruct, y);
    	struct mystruct x = __get_cpu_var(y);
    
       Converts to
    
    	memcpy(this_cpu_ptr(&x), y, sizeof(x));
    
    5. Assignment to a per cpu variable
    
    	DEFINE_PER_CPU(int, y)
    	__get_cpu_var(y) = x;
    
       Converts to
    
    	this_cpu_write(y, x);
    
    6. Increment/Decrement etc of a per cpu variable
    
    	DEFINE_PER_CPU(int, y);
    	__get_cpu_var(y)++
    
       Converts to
    
    	this_cpu_inc(y)
    
    Signed-off-by: Christoph Lameter <cl@linux.com>
    [ paulmck: Address conflicts. ]
    Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index a51985e..450b190 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -400,7 +400,7 @@ static void rcu_eqs_enter(bool user)
 	long long oldval;
 	struct rcu_dynticks *rdtp;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0);
 	if ((oldval & DYNTICK_TASK_NEST_MASK) == DYNTICK_TASK_NEST_VALUE)
@@ -428,7 +428,7 @@ void rcu_idle_enter(void)
 
 	local_irq_save(flags);
 	rcu_eqs_enter(false);
-	rcu_sysidle_enter(&__get_cpu_var(rcu_dynticks), 0);
+	rcu_sysidle_enter(this_cpu_ptr(&rcu_dynticks), 0);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_enter);
@@ -471,7 +471,7 @@ void rcu_irq_exit(void)
 	struct rcu_dynticks *rdtp;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting--;
 	WARN_ON_ONCE(rdtp->dynticks_nesting < 0);
@@ -521,7 +521,7 @@ static void rcu_eqs_exit(bool user)
 	struct rcu_dynticks *rdtp;
 	long long oldval;
 
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE(oldval < 0);
 	if (oldval & DYNTICK_TASK_NEST_MASK)
@@ -548,7 +548,7 @@ void rcu_idle_exit(void)
 
 	local_irq_save(flags);
 	rcu_eqs_exit(false);
-	rcu_sysidle_exit(&__get_cpu_var(rcu_dynticks), 0);
+	rcu_sysidle_exit(this_cpu_ptr(&rcu_dynticks), 0);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_exit);
@@ -592,7 +592,7 @@ void rcu_irq_enter(void)
 	long long oldval;
 
 	local_irq_save(flags);
-	rdtp = &__get_cpu_var(rcu_dynticks);
+	rdtp = this_cpu_ptr(&rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	rdtp->dynticks_nesting++;
 	WARN_ON_ONCE(rdtp->dynticks_nesting == 0);
@@ -613,7 +613,7 @@ void rcu_irq_enter(void)
  */
 void rcu_nmi_enter(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 &&
 	    (atomic_read(&rdtp->dynticks) & 0x1))
@@ -635,7 +635,7 @@ void rcu_nmi_enter(void)
  */
 void rcu_nmi_exit(void)
 {
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 
 	if (rdtp->dynticks_nmi_nesting == 0 ||
 	    --rdtp->dynticks_nmi_nesting != 0)
@@ -658,7 +658,7 @@ int rcu_is_cpu_idle(void)
 	int ret;
 
 	preempt_disable();
-	ret = (atomic_read(&__get_cpu_var(rcu_dynticks).dynticks) & 0x1) == 0;
+	ret = (atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1) == 0;
 	preempt_enable();
 	return ret;
 }
@@ -696,7 +696,7 @@ bool rcu_lockdep_current_cpu_online(void)
 	if (in_nmi())
 		return 1;
 	preempt_disable();
-	rdp = &__get_cpu_var(rcu_sched_data);
+	rdp = this_cpu_ptr(&rcu_sched_data);
 	rnp = rdp->mynode;
 	ret = (rdp->grpmask & rnp->qsmaskinit) ||
 	      !rcu_scheduler_fully_active;
@@ -716,7 +716,7 @@ EXPORT_SYMBOL_GPL(rcu_lockdep_current_cpu_online);
  */
 static int rcu_is_cpu_rrupt_from_idle(void)
 {
-	return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1;
+	return __this_cpu_read(rcu_dynticks.dynticks_nesting) <= 1;
 }
 
 /*
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 08b6e74..dc09fb0 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -660,7 +660,7 @@ static void rcu_preempt_check_callbacks(int cpu)
 
 static void rcu_preempt_do_callbacks(void)
 {
-	rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
+	rcu_do_batch(&rcu_preempt_state, this_cpu_ptr(&rcu_preempt_data));
 }
 
 #endif /* #ifdef CONFIG_RCU_BOOST */
@@ -1332,7 +1332,7 @@ static void invoke_rcu_callbacks_kthread(void)
  */
 static bool rcu_is_callbacks_kthread(void)
 {
-	return __get_cpu_var(rcu_cpu_kthread_task) == current;
+	return __this_cpu_read(rcu_cpu_kthread_task) == current;
 }
 
 #define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000)
@@ -1382,8 +1382,8 @@ static int rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
 
 static void rcu_kthread_do_work(void)
 {
-	rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
-	rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+	rcu_do_batch(&rcu_sched_state, this_cpu_ptr(&rcu_sched_data));
+	rcu_do_batch(&rcu_bh_state, this_cpu_ptr(&rcu_bh_data));
 	rcu_preempt_do_callbacks();
 }
 
@@ -1402,7 +1402,7 @@ static void rcu_cpu_kthread_park(unsigned int cpu)
 
 static int rcu_cpu_kthread_should_run(unsigned int cpu)
 {
-	return __get_cpu_var(rcu_cpu_has_work);
+	return __this_cpu_read(rcu_cpu_has_work);
 }
 
 /*
@@ -1412,8 +1412,8 @@ static int rcu_cpu_kthread_should_run(unsigned int cpu)
  */
 static void rcu_cpu_kthread(unsigned int cpu)
 {
-	unsigned int *statusp = &__get_cpu_var(rcu_cpu_kthread_status);
-	char work, *workp = &__get_cpu_var(rcu_cpu_has_work);
+	unsigned int *statusp = this_cpu_ptr(&rcu_cpu_kthread_status);
+	char work, *workp = this_cpu_ptr(&rcu_cpu_has_work);
 	int spincnt;
 
 	for (spincnt = 0; spincnt < 10; spincnt++) {
@@ -1638,7 +1638,7 @@ static bool rcu_try_advance_all_cbs(void)
 {
 	bool cbs_ready = false;
 	struct rcu_data *rdp;
-	struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
+	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
 	struct rcu_node *rnp;
 	struct rcu_state *rsp;
 

Re: [gcv v3 10/35] rcu: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 4 Sep 2013, Paul E. McKenney wrote:

> Yep, still queued for 3.13, and I even redid the change in
> rcu_is_cpu_idle() to be the way you wanted it.  I wouldn't do that for
> just anyone, you know!  ;-)

Well not everyone is so perfect as you are and has a tree for another
version of the kernel ahead of time.

[gcv v3 11/35] percpu: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/linux/percpu.h
===================================================================
--- linux.orig/include/linux/percpu.h	2013-08-26 14:29:49.000000000 -0500
+++ linux/include/linux/percpu.h	2013-08-26 14:30:18.302570608 -0500
@@ -28,7 +28,7 @@
  */
 #define get_cpu_var(var) (*({				\
 	preempt_disable();				\
-	&__get_cpu_var(var); }))
+	this_cpu_ptr(&var); }))
 
 /*
  * The weird & is necessary because sparse considers (void)(var) to be

[gcv v3 35/35] Remove __get_cpu_var and __raw_get_cpu_var macros [only in 3.13]

[Christoph Lameter]

No user is left in the kernel source tree. Therefore we can
drop the definitions.

[Patch should not be merged until all the replacement patches have been
merged. Probably this means hold until the 3.13 merge window]

Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/include/asm-generic/percpu.h
===================================================================
--- linux.orig/include/asm-generic/percpu.h	2013-08-26 14:40:32.528082727 -0500
+++ linux/include/asm-generic/percpu.h	2013-08-26 14:40:32.520082812 -0500
@@ -65,9 +65,6 @@ extern unsigned long __per_cpu_offset[NR
 #define this_cpu_ptr(ptr) __this_cpu_ptr(ptr)
 #endif
 
-#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
-#define __raw_get_cpu_var(var) (*__this_cpu_ptr(&(var)))
-
 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
 extern void setup_per_cpu_areas(void);
 #endif
@@ -80,8 +77,6 @@ extern void setup_per_cpu_areas(void);
 })
 
 #define per_cpu(var, cpu)	(*((void)(cpu), VERIFY_PERCPU_PTR(&(var))))
-#define __get_cpu_var(var)	(*VERIFY_PERCPU_PTR(&(var)))
-#define __raw_get_cpu_var(var)	(*VERIFY_PERCPU_PTR(&(var)))
 #define this_cpu_ptr(ptr)	per_cpu_ptr(ptr, 0)
 #define __this_cpu_ptr(ptr)	this_cpu_ptr(ptr)
 

[gcv v3 14/35] drivers/char: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/char/random.c
===================================================================
--- linux.orig/drivers/char/random.c	2013-08-27 14:31:00.000000000 -0500
+++ linux/drivers/char/random.c	2013-08-27 14:31:34.275916299 -0500
@@ -744,7 +744,7 @@ static DEFINE_PER_CPU(struct fast_pool,
 void add_interrupt_randomness(int irq, int irq_flags)
 {
 	struct entropy_store	*r;
-	struct fast_pool	*fast_pool = &__get_cpu_var(irq_randomness);
+	struct fast_pool	*fast_pool = this_cpu_ptr(&irq_randomness);
 	struct pt_regs		*regs = get_irq_regs();
 	unsigned long		now = jiffies;
 	__u32			input[4], cycles = get_cycles();

[gcv v3 14/35] drivers/char: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/char/random.c
===================================================================
--- linux.orig/drivers/char/random.c	2013-08-27 14:31:00.000000000 -0500
+++ linux/drivers/char/random.c	2013-08-27 14:31:34.275916299 -0500
@@ -744,7 +744,7 @@ static DEFINE_PER_CPU(struct fast_pool,
 void add_interrupt_randomness(int irq, int irq_flags)
 {
 	struct entropy_store	*r;
-	struct fast_pool	*fast_pool = &__get_cpu_var(irq_randomness);
+	struct fast_pool	*fast_pool = this_cpu_ptr(&irq_randomness);
 	struct pt_regs		*regs = get_irq_regs();
 	unsigned long		now = jiffies;
 	__u32			input[4], cycles = get_cycles();

[gcv v3 29/35] avr32: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/avr32/kernel/kprobes.c
===================================================================
--- linux.orig/arch/avr32/kernel/kprobes.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/avr32/kernel/kprobes.c	2013-08-26 13:27:09.758485808 -0500
@@ -104,7 +104,7 @@ static void __kprobes resume_execution(s
 
 static void __kprobes set_current_kprobe(struct kprobe *p)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 static int __kprobes kprobe_handler(struct pt_regs *regs)

[gcv v3 26/35] sparc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/sparc/include/asm/cpudata_32.h
===================================================================
--- linux.orig/arch/sparc/include/asm/cpudata_32.h	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/include/asm/cpudata_32.h	2013-08-22 14:37:15.942964723 -0500
@@ -26,6 +26,6 @@ typedef struct {
 
 DECLARE_PER_CPU(cpuinfo_sparc, __cpu_data);
 #define cpu_data(__cpu) per_cpu(__cpu_data, (__cpu))
-#define local_cpu_data() __get_cpu_var(__cpu_data)
+#define local_cpu_data() __this_cpu_read(__cpu_data)
 
 #endif /* _SPARC_CPUDATA_H */
Index: linux/arch/sparc/include/asm/cpudata_64.h
===================================================================
--- linux.orig/arch/sparc/include/asm/cpudata_64.h	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/include/asm/cpudata_64.h	2013-08-22 14:37:15.942964723 -0500
@@ -33,7 +33,7 @@ typedef struct {
 
 DECLARE_PER_CPU(cpuinfo_sparc, __cpu_data);
 #define cpu_data(__cpu)		per_cpu(__cpu_data, (__cpu))
-#define local_cpu_data()	__get_cpu_var(__cpu_data)
+#define local_cpu_data()	__this_cpu_read(__cpu_data)
 
 extern const struct seq_operations cpuinfo_op;
 
Index: linux/arch/sparc/kernel/kprobes.c
===================================================================
--- linux.orig/arch/sparc/kernel/kprobes.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/kprobes.c	2013-08-22 14:37:15.942964723 -0500
@@ -82,7 +82,7 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_orig_tnpc = kcb->prev_kprobe.orig_tnpc;
 	kcb->kprobe_orig_tstate_pil = kcb->prev_kprobe.orig_tstate_pil;
@@ -91,7 +91,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 				struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_orig_tnpc = regs->tnpc;
 	kcb->kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL);
 }
@@ -154,7 +154,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs))
 				goto ss_probe;
 		}
Index: linux/arch/sparc/kernel/leon_smp.c
===================================================================
--- linux.orig/arch/sparc/kernel/leon_smp.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/leon_smp.c	2013-08-22 14:37:15.942964723 -0500
@@ -354,7 +354,7 @@ static void leon_ipi_resched(int cpu)
 
 void leonsmp_ipi_interrupt(void)
 {
-	struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
+	struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
 
 	if (work->single) {
 		work->single = 0;
Index: linux/arch/sparc/kernel/nmi.c
===================================================================
--- linux.orig/arch/sparc/kernel/nmi.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/nmi.c	2013-08-22 14:37:15.942964723 -0500
@@ -111,20 +111,20 @@ notrace __kprobes void perfctr_irq(int i
 		pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
 
 	sum = local_cpu_data().irq0_irqs;
-	if (__get_cpu_var(nmi_touch)) {
-		__get_cpu_var(nmi_touch) = 0;
+	if (__this_cpu_read(nmi_touch)) {
+		__this_cpu_write(nmi_touch, 0);
 		touched = 1;
 	}
-	if (!touched && __get_cpu_var(last_irq_sum) == sum) {
+	if (!touched && __this_cpu_read(last_irq_sum) == sum) {
 		__this_cpu_inc(alert_counter);
 		if (__this_cpu_read(alert_counter) == 30 * nmi_hz)
 			die_nmi("BUG: NMI Watchdog detected LOCKUP",
 				regs, panic_on_timeout);
 	} else {
-		__get_cpu_var(last_irq_sum) = sum;
+		__this_cpu_write(last_irq_sum, sum);
 		__this_cpu_write(alert_counter, 0);
 	}
-	if (__get_cpu_var(wd_enabled)) {
+	if (__this_cpu_read(wd_enabled)) {
 		pcr_ops->write_pic(0, pcr_ops->nmi_picl_value(nmi_hz));
 		pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_enable);
 	}
@@ -166,7 +166,7 @@ static void report_broken_nmi(int cpu, i
 void stop_nmi_watchdog(void *unused)
 {
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
-	__get_cpu_var(wd_enabled) = 0;
+	__this_cpu_write(wd_enabled, 0);
 	atomic_dec(&nmi_active);
 }
 
@@ -219,7 +219,7 @@ error:
 
 void start_nmi_watchdog(void *unused)
 {
-	__get_cpu_var(wd_enabled) = 1;
+	__this_cpu_write(wd_enabled, 1);
 	atomic_inc(&nmi_active);
 
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
@@ -230,7 +230,7 @@ void start_nmi_watchdog(void *unused)
 
 static void nmi_adjust_hz_one(void *unused)
 {
-	if (!__get_cpu_var(wd_enabled))
+	if (!__this_cpu_read(wd_enabled))
 		return;
 
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
Index: linux/arch/sparc/kernel/pci_sun4v.c
===================================================================
--- linux.orig/arch/sparc/kernel/pci_sun4v.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/pci_sun4v.c	2013-08-22 14:37:15.942964723 -0500
@@ -48,7 +48,7 @@ static int iommu_batch_initialized;
 /* Interrupts must be disabled.  */
 static inline void iommu_batch_start(struct device *dev, unsigned long prot, unsigned long entry)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	p->dev		= dev;
 	p->prot		= prot;
@@ -94,7 +94,7 @@ static long iommu_batch_flush(struct iom
 
 static inline void iommu_batch_new_entry(unsigned long entry)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	if (p->entry + p->npages == entry)
 		return;
@@ -106,7 +106,7 @@ static inline void iommu_batch_new_entry
 /* Interrupts must be disabled.  */
 static inline long iommu_batch_add(u64 phys_page)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	BUG_ON(p->npages >= PGLIST_NENTS);
 
@@ -120,7 +120,7 @@ static inline long iommu_batch_add(u64 p
 /* Interrupts must be disabled.  */
 static inline long iommu_batch_end(void)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	BUG_ON(p->npages >= PGLIST_NENTS);
 
Index: linux/arch/sparc/kernel/perf_event.c
===================================================================
--- linux.orig/arch/sparc/kernel/perf_event.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/perf_event.c	2013-08-22 14:37:15.946964681 -0500
@@ -1013,7 +1013,7 @@ static void update_pcrs_for_enable(struc
 
 static void sparc_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	if (cpuc->enabled)
@@ -1031,7 +1031,7 @@ static void sparc_pmu_enable(struct pmu
 
 static void sparc_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	if (!cpuc->enabled)
@@ -1065,7 +1065,7 @@ static int active_event_index(struct cpu
 
 static void sparc_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = active_event_index(cpuc, event);
 
 	if (flags & PERF_EF_RELOAD) {
@@ -1080,7 +1080,7 @@ static void sparc_pmu_start(struct perf_
 
 static void sparc_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = active_event_index(cpuc, event);
 
 	if (!(event->hw.state & PERF_HES_STOPPED)) {
@@ -1096,7 +1096,7 @@ static void sparc_pmu_stop(struct perf_e
 
 static void sparc_pmu_del(struct perf_event *event, int _flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long flags;
 	int i;
 
@@ -1133,7 +1133,7 @@ static void sparc_pmu_del(struct perf_ev
 
 static void sparc_pmu_read(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = active_event_index(cpuc, event);
 	struct hw_perf_event *hwc = &event->hw;
 
@@ -1145,7 +1145,7 @@ static DEFINE_MUTEX(pmc_grab_mutex);
 
 static void perf_stop_nmi_watchdog(void *unused)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	stop_nmi_watchdog(NULL);
@@ -1356,7 +1356,7 @@ static int collect_events(struct perf_ev
 
 static int sparc_pmu_add(struct perf_event *event, int ef_flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int n0, ret = -EAGAIN;
 	unsigned long flags;
 
@@ -1498,7 +1498,7 @@ static int sparc_pmu_event_init(struct p
  */
 static void sparc_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	perf_pmu_disable(pmu);
 	cpuhw->group_flag |= PERF_EVENT_TXN;
@@ -1511,7 +1511,7 @@ static void sparc_pmu_start_txn(struct p
  */
 static void sparc_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	cpuhw->group_flag &= ~PERF_EVENT_TXN;
 	perf_pmu_enable(pmu);
@@ -1524,13 +1524,13 @@ static void sparc_pmu_cancel_txn(struct
  */
 static int sparc_pmu_commit_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int n;
 
 	if (!sparc_pmu)
 		return -EINVAL;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 	n = cpuc->n_events;
 	if (check_excludes(cpuc->event, 0, n))
 		return -EINVAL;
@@ -1601,7 +1601,7 @@ static int __kprobes perf_event_nmi_hand
 
 	regs = args->regs;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/* If the PMU has the TOE IRQ enable bits, we need to do a
 	 * dummy write to the %pcr to clear the overflow bits and thus
Index: linux/arch/sparc/kernel/sun4d_smp.c
===================================================================
--- linux.orig/arch/sparc/kernel/sun4d_smp.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/sun4d_smp.c	2013-08-22 14:37:15.946964681 -0500
@@ -204,7 +204,7 @@ static void __init smp4d_ipi_init(void)
 
 void sun4d_ipi_interrupt(void)
 {
-	struct sun4d_ipi_work *work = &__get_cpu_var(sun4d_ipi_work);
+	struct sun4d_ipi_work *work = this_cpu_ptr(&sun4d_ipi_work);
 
 	if (work->single) {
 		work->single = 0;
Index: linux/arch/sparc/kernel/time_64.c
===================================================================
--- linux.orig/arch/sparc/kernel/time_64.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/time_64.c	2013-08-22 14:37:15.946964681 -0500
@@ -766,7 +766,7 @@ void setup_sparc64_timer(void)
 			     : /* no outputs */
 			     : "r" (pstate));
 
-	sevt = &__get_cpu_var(sparc64_events);
+	sevt = this_cpu_ptr(&sparc64_events);
 
 	memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
 	sevt->cpumask = cpumask_of(smp_processor_id());
Index: linux/arch/sparc/mm/tlb.c
===================================================================
--- linux.orig/arch/sparc/mm/tlb.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/mm/tlb.c	2013-08-22 14:37:15.946964681 -0500
@@ -53,14 +53,14 @@ out:
 
 void arch_enter_lazy_mmu_mode(void)
 {
-	struct tlb_batch *tb = &__get_cpu_var(tlb_batch);
+	struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
 
 	tb->active = 1;
 }
 
 void arch_leave_lazy_mmu_mode(void)
 {
-	struct tlb_batch *tb = &__get_cpu_var(tlb_batch);
+	struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
 
 	if (tb->tlb_nr)
 		flush_tlb_pending();

[gcv v3 26/35] sparc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)


Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/sparc/include/asm/cpudata_32.h
===================================================================
--- linux.orig/arch/sparc/include/asm/cpudata_32.h	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/include/asm/cpudata_32.h	2013-08-22 14:37:15.942964723 -0500
@@ -26,6 +26,6 @@ typedef struct {
 
 DECLARE_PER_CPU(cpuinfo_sparc, __cpu_data);
 #define cpu_data(__cpu) per_cpu(__cpu_data, (__cpu))
-#define local_cpu_data() __get_cpu_var(__cpu_data)
+#define local_cpu_data() __this_cpu_read(__cpu_data)
 
 #endif /* _SPARC_CPUDATA_H */
Index: linux/arch/sparc/include/asm/cpudata_64.h
===================================================================
--- linux.orig/arch/sparc/include/asm/cpudata_64.h	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/include/asm/cpudata_64.h	2013-08-22 14:37:15.942964723 -0500
@@ -33,7 +33,7 @@ typedef struct {
 
 DECLARE_PER_CPU(cpuinfo_sparc, __cpu_data);
 #define cpu_data(__cpu)		per_cpu(__cpu_data, (__cpu))
-#define local_cpu_data()	__get_cpu_var(__cpu_data)
+#define local_cpu_data()	__this_cpu_read(__cpu_data)
 
 extern const struct seq_operations cpuinfo_op;
 
Index: linux/arch/sparc/kernel/kprobes.c
===================================================================
--- linux.orig/arch/sparc/kernel/kprobes.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/kprobes.c	2013-08-22 14:37:15.942964723 -0500
@@ -82,7 +82,7 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 	kcb->kprobe_orig_tnpc = kcb->prev_kprobe.orig_tnpc;
 	kcb->kprobe_orig_tstate_pil = kcb->prev_kprobe.orig_tstate_pil;
@@ -91,7 +91,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 				struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 	kcb->kprobe_orig_tnpc = regs->tnpc;
 	kcb->kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL);
 }
@@ -154,7 +154,7 @@ static int __kprobes kprobe_handler(stru
 				ret = 1;
 				goto no_kprobe;
 			}
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs))
 				goto ss_probe;
 		}
Index: linux/arch/sparc/kernel/leon_smp.c
===================================================================
--- linux.orig/arch/sparc/kernel/leon_smp.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/leon_smp.c	2013-08-22 14:37:15.942964723 -0500
@@ -354,7 +354,7 @@ static void leon_ipi_resched(int cpu)
 
 void leonsmp_ipi_interrupt(void)
 {
-	struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
+	struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
 
 	if (work->single) {
 		work->single = 0;
Index: linux/arch/sparc/kernel/nmi.c
===================================================================
--- linux.orig/arch/sparc/kernel/nmi.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/nmi.c	2013-08-22 14:37:15.942964723 -0500
@@ -111,20 +111,20 @@ notrace __kprobes void perfctr_irq(int i
 		pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
 
 	sum = local_cpu_data().irq0_irqs;
-	if (__get_cpu_var(nmi_touch)) {
-		__get_cpu_var(nmi_touch) = 0;
+	if (__this_cpu_read(nmi_touch)) {
+		__this_cpu_write(nmi_touch, 0);
 		touched = 1;
 	}
-	if (!touched && __get_cpu_var(last_irq_sum) == sum) {
+	if (!touched && __this_cpu_read(last_irq_sum) == sum) {
 		__this_cpu_inc(alert_counter);
 		if (__this_cpu_read(alert_counter) == 30 * nmi_hz)
 			die_nmi("BUG: NMI Watchdog detected LOCKUP",
 				regs, panic_on_timeout);
 	} else {
-		__get_cpu_var(last_irq_sum) = sum;
+		__this_cpu_write(last_irq_sum, sum);
 		__this_cpu_write(alert_counter, 0);
 	}
-	if (__get_cpu_var(wd_enabled)) {
+	if (__this_cpu_read(wd_enabled)) {
 		pcr_ops->write_pic(0, pcr_ops->nmi_picl_value(nmi_hz));
 		pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_enable);
 	}
@@ -166,7 +166,7 @@ static void report_broken_nmi(int cpu, i
 void stop_nmi_watchdog(void *unused)
 {
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
-	__get_cpu_var(wd_enabled) = 0;
+	__this_cpu_write(wd_enabled, 0);
 	atomic_dec(&nmi_active);
 }
 
@@ -219,7 +219,7 @@ error:
 
 void start_nmi_watchdog(void *unused)
 {
-	__get_cpu_var(wd_enabled) = 1;
+	__this_cpu_write(wd_enabled, 1);
 	atomic_inc(&nmi_active);
 
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
@@ -230,7 +230,7 @@ void start_nmi_watchdog(void *unused)
 
 static void nmi_adjust_hz_one(void *unused)
 {
-	if (!__get_cpu_var(wd_enabled))
+	if (!__this_cpu_read(wd_enabled))
 		return;
 
 	pcr_ops->write_pcr(0, pcr_ops->pcr_nmi_disable);
Index: linux/arch/sparc/kernel/pci_sun4v.c
===================================================================
--- linux.orig/arch/sparc/kernel/pci_sun4v.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/pci_sun4v.c	2013-08-22 14:37:15.942964723 -0500
@@ -48,7 +48,7 @@ static int iommu_batch_initialized;
 /* Interrupts must be disabled.  */
 static inline void iommu_batch_start(struct device *dev, unsigned long prot, unsigned long entry)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	p->dev		= dev;
 	p->prot		= prot;
@@ -94,7 +94,7 @@ static long iommu_batch_flush(struct iom
 
 static inline void iommu_batch_new_entry(unsigned long entry)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	if (p->entry + p->npages == entry)
 		return;
@@ -106,7 +106,7 @@ static inline void iommu_batch_new_entry
 /* Interrupts must be disabled.  */
 static inline long iommu_batch_add(u64 phys_page)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	BUG_ON(p->npages >= PGLIST_NENTS);
 
@@ -120,7 +120,7 @@ static inline long iommu_batch_add(u64 p
 /* Interrupts must be disabled.  */
 static inline long iommu_batch_end(void)
 {
-	struct iommu_batch *p = &__get_cpu_var(iommu_batch);
+	struct iommu_batch *p = this_cpu_ptr(&iommu_batch);
 
 	BUG_ON(p->npages >= PGLIST_NENTS);
 
Index: linux/arch/sparc/kernel/perf_event.c
===================================================================
--- linux.orig/arch/sparc/kernel/perf_event.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/perf_event.c	2013-08-22 14:37:15.946964681 -0500
@@ -1013,7 +1013,7 @@ static void update_pcrs_for_enable(struc
 
 static void sparc_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	if (cpuc->enabled)
@@ -1031,7 +1031,7 @@ static void sparc_pmu_enable(struct pmu
 
 static void sparc_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	if (!cpuc->enabled)
@@ -1065,7 +1065,7 @@ static int active_event_index(struct cpu
 
 static void sparc_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = active_event_index(cpuc, event);
 
 	if (flags & PERF_EF_RELOAD) {
@@ -1080,7 +1080,7 @@ static void sparc_pmu_start(struct perf_
 
 static void sparc_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = active_event_index(cpuc, event);
 
 	if (!(event->hw.state & PERF_HES_STOPPED)) {
@@ -1096,7 +1096,7 @@ static void sparc_pmu_stop(struct perf_e
 
 static void sparc_pmu_del(struct perf_event *event, int _flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long flags;
 	int i;
 
@@ -1133,7 +1133,7 @@ static void sparc_pmu_del(struct perf_ev
 
 static void sparc_pmu_read(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = active_event_index(cpuc, event);
 	struct hw_perf_event *hwc = &event->hw;
 
@@ -1145,7 +1145,7 @@ static DEFINE_MUTEX(pmc_grab_mutex);
 
 static void perf_stop_nmi_watchdog(void *unused)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	stop_nmi_watchdog(NULL);
@@ -1356,7 +1356,7 @@ static int collect_events(struct perf_ev
 
 static int sparc_pmu_add(struct perf_event *event, int ef_flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int n0, ret = -EAGAIN;
 	unsigned long flags;
 
@@ -1498,7 +1498,7 @@ static int sparc_pmu_event_init(struct p
  */
 static void sparc_pmu_start_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	perf_pmu_disable(pmu);
 	cpuhw->group_flag |= PERF_EVENT_TXN;
@@ -1511,7 +1511,7 @@ static void sparc_pmu_start_txn(struct p
  */
 static void sparc_pmu_cancel_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuhw = this_cpu_ptr(&cpu_hw_events);
 
 	cpuhw->group_flag &= ~PERF_EVENT_TXN;
 	perf_pmu_enable(pmu);
@@ -1524,13 +1524,13 @@ static void sparc_pmu_cancel_txn(struct
  */
 static int sparc_pmu_commit_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int n;
 
 	if (!sparc_pmu)
 		return -EINVAL;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 	n = cpuc->n_events;
 	if (check_excludes(cpuc->event, 0, n))
 		return -EINVAL;
@@ -1601,7 +1601,7 @@ static int __kprobes perf_event_nmi_hand
 
 	regs = args->regs;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/* If the PMU has the TOE IRQ enable bits, we need to do a
 	 * dummy write to the %pcr to clear the overflow bits and thus
Index: linux/arch/sparc/kernel/sun4d_smp.c
===================================================================
--- linux.orig/arch/sparc/kernel/sun4d_smp.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/sun4d_smp.c	2013-08-22 14:37:15.946964681 -0500
@@ -204,7 +204,7 @@ static void __init smp4d_ipi_init(void)
 
 void sun4d_ipi_interrupt(void)
 {
-	struct sun4d_ipi_work *work = &__get_cpu_var(sun4d_ipi_work);
+	struct sun4d_ipi_work *work = this_cpu_ptr(&sun4d_ipi_work);
 
 	if (work->single) {
 		work->single = 0;
Index: linux/arch/sparc/kernel/time_64.c
===================================================================
--- linux.orig/arch/sparc/kernel/time_64.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/kernel/time_64.c	2013-08-22 14:37:15.946964681 -0500
@@ -766,7 +766,7 @@ void setup_sparc64_timer(void)
 			     : /* no outputs */
 			     : "r" (pstate));
 
-	sevt = &__get_cpu_var(sparc64_events);
+	sevt = this_cpu_ptr(&sparc64_events);
 
 	memcpy(sevt, &sparc64_clockevent, sizeof(*sevt));
 	sevt->cpumask = cpumask_of(smp_processor_id());
Index: linux/arch/sparc/mm/tlb.c
===================================================================
--- linux.orig/arch/sparc/mm/tlb.c	2013-08-22 14:34:54.000000000 -0500
+++ linux/arch/sparc/mm/tlb.c	2013-08-22 14:37:15.946964681 -0500
@@ -53,14 +53,14 @@ out:
 
 void arch_enter_lazy_mmu_mode(void)
 {
-	struct tlb_batch *tb = &__get_cpu_var(tlb_batch);
+	struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
 
 	tb->active = 1;
 }
 
 void arch_leave_lazy_mmu_mode(void)
 {
-	struct tlb_batch *tb = &__get_cpu_var(tlb_batch);
+	struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
 
 	if (tb->tlb_nr)
 		flush_tlb_pending();

[gcv v3 24/35] ia64: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/alpha/kernel/perf_event.c
===================================================================
--- linux.orig/arch/alpha/kernel/perf_event.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/alpha/kernel/perf_event.c	2013-08-23 09:10:22.665620124 -0500
@@ -803,7 +803,7 @@ static void alpha_perf_event_irq_handler
 	struct hw_perf_event *hwc;
 	int idx, j;
 
-	__get_cpu_var(irq_pmi_count)++;
+	__this_cpu_inc(irq_pmi_count);
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
 	/* Completely counting through the PMC's period to trigger a new PMC
Index: linux/arch/ia64/kernel/irq.c
===================================================================
--- linux.orig/arch/ia64/kernel/irq.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/irq.c	2013-08-23 09:10:22.665620124 -0500
@@ -42,7 +42,7 @@ ia64_vector __ia64_irq_to_vector(int irq
 
 unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
 {
-	return __get_cpu_var(vector_irq)[vec];
+	return __this_cpu_read(vector_irq[vec]);
 }
 #endif
 
Index: linux/arch/ia64/kernel/irq_ia64.c
===================================================================
--- linux.orig/arch/ia64/kernel/irq_ia64.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/irq_ia64.c	2013-08-23 09:10:22.669620084 -0500
@@ -338,7 +338,7 @@ static irqreturn_t smp_irq_move_cleanup_
 		int irq;
 		struct irq_desc *desc;
 		struct irq_cfg *cfg;
-		irq = __get_cpu_var(vector_irq)[vector];
+		irq = __this_cpu_read(vector_irq[vector]);
 		if (irq < 0)
 			continue;
 
@@ -352,7 +352,7 @@ static irqreturn_t smp_irq_move_cleanup_
 			goto unlock;
 
 		spin_lock_irqsave(&vector_lock, flags);
-		__get_cpu_var(vector_irq)[vector] = -1;
+		__this_cpu_write(vector_irq[vector], -1);
 		cpu_clear(me, vector_table[vector]);
 		spin_unlock_irqrestore(&vector_lock, flags);
 		cfg->move_cleanup_count--;
Index: linux/arch/ia64/kernel/kprobes.c
===================================================================
--- linux.orig/arch/ia64/kernel/kprobes.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/kprobes.c	2013-08-23 09:10:22.669620084 -0500
@@ -396,7 +396,7 @@ static void __kprobes restore_previous_k
 {
 	unsigned int i;
 	i = atomic_read(&kcb->prev_kprobe_index);
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe[i-1].kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe[i-1].kp);
 	kcb->kprobe_status = kcb->prev_kprobe[i-1].status;
 	atomic_sub(1, &kcb->prev_kprobe_index);
 }
@@ -404,7 +404,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p,
 			struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 static void kretprobe_trampoline(void)
@@ -823,7 +823,7 @@ static int __kprobes pre_kprobes_handler
 			/*
 			 * jprobe instrumented function just completed
 			 */
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
Index: linux/arch/ia64/kernel/mca.c
===================================================================
--- linux.orig/arch/ia64/kernel/mca.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/mca.c	2013-08-23 09:11:54.244715775 -0500
@@ -1341,7 +1341,7 @@ ia64_mca_handler(struct pt_regs *regs, s
 		ia64_mlogbuf_finish(1);
 	}
 
-	if (__get_cpu_var(ia64_mca_tr_reload)) {
+	if (__this_cpu_read(ia64_mca_tr_reload)) {
 		mca_insert_tr(0x1); /*Reload dynamic itrs*/
 		mca_insert_tr(0x2); /*Reload dynamic itrs*/
 	}
@@ -1874,14 +1874,14 @@ ia64_mca_cpu_init(void *cpu_data)
 		"MCA", cpu);
 	format_mca_init_stack(data, offsetof(struct ia64_mca_cpu, init_stack),
 		"INIT", cpu);
-	__get_cpu_var(ia64_mca_data) = __per_cpu_mca[cpu] = __pa(data);
+	__this_cpu_write(ia64_mca_data, __per_cpu_mca[cpu] = __pa(data));
 
 	/*
 	 * Stash away a copy of the PTE needed to map the per-CPU page.
 	 * We may need it during MCA recovery.
 	 */
-	__get_cpu_var(ia64_mca_per_cpu_pte) =
-		pte_val(mk_pte_phys(__pa(cpu_data), PAGE_KERNEL));
+	__this_cpu_write(ia64_mca_per_cpu_pte,
+		pte_val(mk_pte_phys(__pa(cpu_data), PAGE_KERNEL)));
 
 	/*
 	 * Also, stash away a copy of the PAL address and the PTE
@@ -1890,10 +1890,10 @@ ia64_mca_cpu_init(void *cpu_data)
 	pal_vaddr = efi_get_pal_addr();
 	if (!pal_vaddr)
 		return;
-	__get_cpu_var(ia64_mca_pal_base) =
-		GRANULEROUNDDOWN((unsigned long) pal_vaddr);
-	__get_cpu_var(ia64_mca_pal_pte) = pte_val(mk_pte_phys(__pa(pal_vaddr),
-							      PAGE_KERNEL));
+	__this_cpu_write(ia64_mca_pal_base,
+		GRANULEROUNDDOWN((unsigned long) pal_vaddr));
+	__this_cpu_write(ia64_mca_pal_pte, pte_val(mk_pte_phys(__pa(pal_vaddr),
+							      PAGE_KERNEL)));
 }
 
 static void ia64_mca_cmc_vector_adjust(void *dummy)
Index: linux/arch/ia64/kernel/process.c
===================================================================
--- linux.orig/arch/ia64/kernel/process.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/process.c	2013-08-23 09:10:22.669620084 -0500
@@ -215,7 +215,7 @@ static inline void play_dead(void)
 	unsigned int this_cpu = smp_processor_id();
 
 	/* Ack it */
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 
 	max_xtp();
 	local_irq_disable();
@@ -273,7 +273,7 @@ ia64_save_extra (struct task_struct *tas
 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
 		pfm_save_regs(task);
 
-	info = __get_cpu_var(pfm_syst_info);
+	info = __this_cpu_read(pfm_syst_info);
 	if (info & PFM_CPUINFO_SYST_WIDE)
 		pfm_syst_wide_update_task(task, info, 0);
 #endif
@@ -293,7 +293,7 @@ ia64_load_extra (struct task_struct *tas
 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
 		pfm_load_regs(task);
 
-	info = __get_cpu_var(pfm_syst_info);
+	info = __this_cpu_read(pfm_syst_info);
 	if (info & PFM_CPUINFO_SYST_WIDE) 
 		pfm_syst_wide_update_task(task, info, 1);
 #endif
Index: linux/arch/ia64/sn/kernel/sn2/sn2_smp.c
===================================================================
--- linux.orig/arch/ia64/sn/kernel/sn2/sn2_smp.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/sn/kernel/sn2/sn2_smp.c	2013-08-23 09:10:22.669620084 -0500
@@ -134,8 +134,8 @@ sn2_ipi_flush_all_tlb(struct mm_struct *
 	itc = ia64_get_itc();
 	smp_flush_tlb_cpumask(*mm_cpumask(mm));
 	itc = ia64_get_itc() - itc;
-	__get_cpu_var(ptcstats).shub_ipi_flushes_itc_clocks += itc;
-	__get_cpu_var(ptcstats).shub_ipi_flushes++;
+	__this_cpu_add(ptcstats.shub_ipi_flushes_itc_clocks, itc);
+	__this_cpu_inc(ptcstats.shub_ipi_flushes);
 }
 
 /**
@@ -199,14 +199,14 @@ sn2_global_tlb_purge(struct mm_struct *m
 			start += (1UL << nbits);
 		} while (start < end);
 		ia64_srlz_i();
-		__get_cpu_var(ptcstats).ptc_l++;
+		__this_cpu_inc(ptcstats.ptc_l);
 		preempt_enable();
 		return;
 	}
 
 	if (atomic_read(&mm->mm_users) == 1 && mymm) {
 		flush_tlb_mm(mm);
-		__get_cpu_var(ptcstats).change_rid++;
+		__this_cpu_inc(ptcstats.change_rid);
 		preempt_enable();
 		return;
 	}
@@ -250,11 +250,11 @@ sn2_global_tlb_purge(struct mm_struct *m
 	spin_lock_irqsave(PTC_LOCK(shub1), flags);
 	itc2 = ia64_get_itc();
 
-	__get_cpu_var(ptcstats).lock_itc_clocks += itc2 - itc;
-	__get_cpu_var(ptcstats).shub_ptc_flushes++;
-	__get_cpu_var(ptcstats).nodes_flushed += nix;
+	__this_cpu_add(ptcstats.lock_itc_clocks, itc2 - itc);
+	__this_cpu_inc(ptcstats.shub_ptc_flushes);
+	__this_cpu_add(ptcstats.nodes_flushed, nix);
 	if (!mymm)
-		 __get_cpu_var(ptcstats).shub_ptc_flushes_not_my_mm++;
+		 __this_cpu_inc(ptcstats.shub_ptc_flushes_not_my_mm);
 
 	if (use_cpu_ptcga && !mymm) {
 		old_rr = ia64_get_rr(start);
@@ -299,9 +299,9 @@ sn2_global_tlb_purge(struct mm_struct *m
 
 done:
 	itc2 = ia64_get_itc() - itc2;
-	__get_cpu_var(ptcstats).shub_itc_clocks += itc2;
-	if (itc2 > __get_cpu_var(ptcstats).shub_itc_clocks_max)
-		__get_cpu_var(ptcstats).shub_itc_clocks_max = itc2;
+	__this_cpu_add(ptcstats)shub_itc_clocks, itc2);
+	if (itc2 > __this_cpu_read(ptcstats.shub_itc_clocks_max))
+		__this_cpu_write(ptcstats).shub_itc_clocks_max, itc2);
 
 	if (old_rr) {
 		ia64_set_rr(start, old_rr);
@@ -311,7 +311,7 @@ done:
 	spin_unlock_irqrestore(PTC_LOCK(shub1), flags);
 
 	if (flush_opt == 1 && deadlock) {
-		__get_cpu_var(ptcstats).deadlocks++;
+		__this_cpu_inc(ptcstats.deadlocks);
 		sn2_ipi_flush_all_tlb(mm);
 	}
 
@@ -334,7 +334,7 @@ sn2_ptc_deadlock_recovery(short *nasids,
 	short nasid, i;
 	unsigned long *piows, zeroval, n;
 
-	__get_cpu_var(ptcstats).deadlocks++;
+	__this_cpu_inc(ptcstats.deadlocks);
 
 	piows = (unsigned long *) pda->pio_write_status_addr;
 	zeroval = pda->pio_write_status_val;
@@ -349,7 +349,7 @@ sn2_ptc_deadlock_recovery(short *nasids,
 			ptc1 = CHANGE_NASID(nasid, ptc1);
 
 		n = sn2_ptc_deadlock_recovery_core(ptc0, data0, ptc1, data1, piows, zeroval);
-		__get_cpu_var(ptcstats).deadlocks2 += n;
+		__this_cpu_add(ptcstats.deadlocks2, n);
 	}
 
 }
Index: linux/arch/ia64/include/asm/hw_irq.h
===================================================================
--- linux.orig/arch/ia64/include/asm/hw_irq.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/hw_irq.h	2013-08-23 09:10:22.673620044 -0500
@@ -160,7 +160,7 @@ static inline ia64_vector __ia64_irq_to_
 static inline unsigned int
 __ia64_local_vector_to_irq (ia64_vector vec)
 {
-	return __get_cpu_var(vector_irq)[vec];
+	return __this_cpu_read(vector_irq[vec]);
 }
 #endif
 
Index: linux/arch/ia64/include/asm/sn/nodepda.h
===================================================================
--- linux.orig/arch/ia64/include/asm/sn/nodepda.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/sn/nodepda.h	2013-08-23 09:10:22.673620044 -0500
@@ -70,7 +70,7 @@ typedef struct nodepda_s nodepda_t;
  */
 
 DECLARE_PER_CPU(struct nodepda_s *, __sn_nodepda);
-#define sn_nodepda		(__get_cpu_var(__sn_nodepda))
+#define sn_nodepda		__this_cpu_read(__sn_nodepda)
 #define	NODEPDA(cnodeid)	(sn_nodepda->pernode_pdaindr[cnodeid])
 
 /*
Index: linux/arch/ia64/include/asm/switch_to.h
===================================================================
--- linux.orig/arch/ia64/include/asm/switch_to.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/switch_to.h	2013-08-23 09:10:22.673620044 -0500
@@ -32,7 +32,7 @@ extern void ia64_load_extra (struct task
 
 #ifdef CONFIG_PERFMON
   DECLARE_PER_CPU(unsigned long, pfm_syst_info);
-# define PERFMON_IS_SYSWIDE() (__get_cpu_var(pfm_syst_info) & 0x1)
+# define PERFMON_IS_SYSWIDE() (__this_cpu_read(pfm_syst_info) & 0x1)
 #else
 # define PERFMON_IS_SYSWIDE() (0)
 #endif
Index: linux/arch/ia64/include/asm/sn/arch.h
===================================================================
--- linux.orig/arch/ia64/include/asm/sn/arch.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/sn/arch.h	2013-08-23 09:10:22.673620044 -0500
@@ -57,7 +57,7 @@ struct sn_hub_info_s {
 	u16 nasid_bitmask;
 };
 DECLARE_PER_CPU(struct sn_hub_info_s, __sn_hub_info);
-#define sn_hub_info 	(&__get_cpu_var(__sn_hub_info))
+#define sn_hub_info 	this_cpu_ptr(&__sn_hub_info)
 #define is_shub2()	(sn_hub_info->shub2)
 #define is_shub1()	(sn_hub_info->shub2 == 0)
 
@@ -72,7 +72,7 @@ DECLARE_PER_CPU(struct sn_hub_info_s, __
  * cpu.
  */
 DECLARE_PER_CPU(short, __sn_cnodeid_to_nasid[MAX_COMPACT_NODES]);
-#define sn_cnodeid_to_nasid	(&__get_cpu_var(__sn_cnodeid_to_nasid[0]))
+#define sn_cnodeid_to_nasid	this_cpu_ptr(&__sn_cnodeid_to_nasid[0])
 
 
 extern u8 sn_partition_id;
Index: linux/arch/ia64/include/asm/uv/uv_hub.h
===================================================================
--- linux.orig/arch/ia64/include/asm/uv/uv_hub.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/uv/uv_hub.h	2013-08-23 09:10:22.673620044 -0500
@@ -108,7 +108,7 @@ struct uv_hub_info_s {
 	unsigned char	n_val;
 };
 DECLARE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
-#define uv_hub_info 		(&__get_cpu_var(__uv_hub_info))
+#define uv_hub_info 		this_cpu_ptr(&__uv_hub_info)
 #define uv_cpu_hub_info(cpu)	(&per_cpu(__uv_hub_info, cpu))
 
 /*
Index: linux/arch/ia64/kernel/traps.c
===================================================================
--- linux.orig/arch/ia64/kernel/traps.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/traps.c	2013-08-23 09:10:22.673620044 -0500
@@ -299,7 +299,7 @@ handle_fpu_swa (int fp_fault, struct pt_
 
 	if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT))  {
 		unsigned long count, current_jiffies = jiffies;
-		struct fpu_swa_msg *cp = &__get_cpu_var(cpulast);
+		struct fpu_swa_msg *cp = this_cpu_ptr(&cpulast);
 
 		if (unlikely(current_jiffies > cp->time))
 			cp->count = 0;
Index: linux/arch/ia64/xen/time.c
===================================================================
--- linux.orig/arch/ia64/xen/time.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/xen/time.c	2013-08-23 09:10:22.673620044 -0500
@@ -68,7 +68,7 @@ static void get_runstate_snapshot(struct
 
 	BUG_ON(preemptible());
 
-	state = &__get_cpu_var(xen_runstate);
+	state = this_cpu_ptr(&xen_runstate);
 
 	/*
 	 * The runstate info is always updated by the hypervisor on

[gcv v3 24/35] ia64: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/alpha/kernel/perf_event.c
===================================================================
--- linux.orig/arch/alpha/kernel/perf_event.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/alpha/kernel/perf_event.c	2013-08-23 09:10:22.665620124 -0500
@@ -803,7 +803,7 @@ static void alpha_perf_event_irq_handler
 	struct hw_perf_event *hwc;
 	int idx, j;
 
-	__get_cpu_var(irq_pmi_count)++;
+	__this_cpu_inc(irq_pmi_count);
 	cpuc = &__get_cpu_var(cpu_hw_events);
 
 	/* Completely counting through the PMC's period to trigger a new PMC
Index: linux/arch/ia64/kernel/irq.c
===================================================================
--- linux.orig/arch/ia64/kernel/irq.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/irq.c	2013-08-23 09:10:22.665620124 -0500
@@ -42,7 +42,7 @@ ia64_vector __ia64_irq_to_vector(int irq
 
 unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
 {
-	return __get_cpu_var(vector_irq)[vec];
+	return __this_cpu_read(vector_irq[vec]);
 }
 #endif
 
Index: linux/arch/ia64/kernel/irq_ia64.c
===================================================================
--- linux.orig/arch/ia64/kernel/irq_ia64.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/irq_ia64.c	2013-08-23 09:10:22.669620084 -0500
@@ -338,7 +338,7 @@ static irqreturn_t smp_irq_move_cleanup_
 		int irq;
 		struct irq_desc *desc;
 		struct irq_cfg *cfg;
-		irq = __get_cpu_var(vector_irq)[vector];
+		irq = __this_cpu_read(vector_irq[vector]);
 		if (irq < 0)
 			continue;
 
@@ -352,7 +352,7 @@ static irqreturn_t smp_irq_move_cleanup_
 			goto unlock;
 
 		spin_lock_irqsave(&vector_lock, flags);
-		__get_cpu_var(vector_irq)[vector] = -1;
+		__this_cpu_write(vector_irq[vector], -1);
 		cpu_clear(me, vector_table[vector]);
 		spin_unlock_irqrestore(&vector_lock, flags);
 		cfg->move_cleanup_count--;
Index: linux/arch/ia64/kernel/kprobes.c
===================================================================
--- linux.orig/arch/ia64/kernel/kprobes.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/kprobes.c	2013-08-23 09:10:22.669620084 -0500
@@ -396,7 +396,7 @@ static void __kprobes restore_previous_k
 {
 	unsigned int i;
 	i = atomic_read(&kcb->prev_kprobe_index);
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe[i-1].kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe[i-1].kp);
 	kcb->kprobe_status = kcb->prev_kprobe[i-1].status;
 	atomic_sub(1, &kcb->prev_kprobe_index);
 }
@@ -404,7 +404,7 @@ static void __kprobes restore_previous_k
 static void __kprobes set_current_kprobe(struct kprobe *p,
 			struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 static void kretprobe_trampoline(void)
@@ -823,7 +823,7 @@ static int __kprobes pre_kprobes_handler
 			/*
 			 * jprobe instrumented function just completed
 			 */
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
Index: linux/arch/ia64/kernel/mca.c
===================================================================
--- linux.orig/arch/ia64/kernel/mca.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/mca.c	2013-08-23 09:11:54.244715775 -0500
@@ -1341,7 +1341,7 @@ ia64_mca_handler(struct pt_regs *regs, s
 		ia64_mlogbuf_finish(1);
 	}
 
-	if (__get_cpu_var(ia64_mca_tr_reload)) {
+	if (__this_cpu_read(ia64_mca_tr_reload)) {
 		mca_insert_tr(0x1); /*Reload dynamic itrs*/
 		mca_insert_tr(0x2); /*Reload dynamic itrs*/
 	}
@@ -1874,14 +1874,14 @@ ia64_mca_cpu_init(void *cpu_data)
 		"MCA", cpu);
 	format_mca_init_stack(data, offsetof(struct ia64_mca_cpu, init_stack),
 		"INIT", cpu);
-	__get_cpu_var(ia64_mca_data) = __per_cpu_mca[cpu] = __pa(data);
+	__this_cpu_write(ia64_mca_data, __per_cpu_mca[cpu] = __pa(data));
 
 	/*
 	 * Stash away a copy of the PTE needed to map the per-CPU page.
 	 * We may need it during MCA recovery.
 	 */
-	__get_cpu_var(ia64_mca_per_cpu_pte) =
-		pte_val(mk_pte_phys(__pa(cpu_data), PAGE_KERNEL));
+	__this_cpu_write(ia64_mca_per_cpu_pte,
+		pte_val(mk_pte_phys(__pa(cpu_data), PAGE_KERNEL)));
 
 	/*
 	 * Also, stash away a copy of the PAL address and the PTE
@@ -1890,10 +1890,10 @@ ia64_mca_cpu_init(void *cpu_data)
 	pal_vaddr = efi_get_pal_addr();
 	if (!pal_vaddr)
 		return;
-	__get_cpu_var(ia64_mca_pal_base) =
-		GRANULEROUNDDOWN((unsigned long) pal_vaddr);
-	__get_cpu_var(ia64_mca_pal_pte) = pte_val(mk_pte_phys(__pa(pal_vaddr),
-							      PAGE_KERNEL));
+	__this_cpu_write(ia64_mca_pal_base,
+		GRANULEROUNDDOWN((unsigned long) pal_vaddr));
+	__this_cpu_write(ia64_mca_pal_pte, pte_val(mk_pte_phys(__pa(pal_vaddr),
+							      PAGE_KERNEL)));
 }
 
 static void ia64_mca_cmc_vector_adjust(void *dummy)
Index: linux/arch/ia64/kernel/process.c
===================================================================
--- linux.orig/arch/ia64/kernel/process.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/process.c	2013-08-23 09:10:22.669620084 -0500
@@ -215,7 +215,7 @@ static inline void play_dead(void)
 	unsigned int this_cpu = smp_processor_id();
 
 	/* Ack it */
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 
 	max_xtp();
 	local_irq_disable();
@@ -273,7 +273,7 @@ ia64_save_extra (struct task_struct *tas
 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
 		pfm_save_regs(task);
 
-	info = __get_cpu_var(pfm_syst_info);
+	info = __this_cpu_read(pfm_syst_info);
 	if (info & PFM_CPUINFO_SYST_WIDE)
 		pfm_syst_wide_update_task(task, info, 0);
 #endif
@@ -293,7 +293,7 @@ ia64_load_extra (struct task_struct *tas
 	if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
 		pfm_load_regs(task);
 
-	info = __get_cpu_var(pfm_syst_info);
+	info = __this_cpu_read(pfm_syst_info);
 	if (info & PFM_CPUINFO_SYST_WIDE) 
 		pfm_syst_wide_update_task(task, info, 1);
 #endif
Index: linux/arch/ia64/sn/kernel/sn2/sn2_smp.c
===================================================================
--- linux.orig/arch/ia64/sn/kernel/sn2/sn2_smp.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/sn/kernel/sn2/sn2_smp.c	2013-08-23 09:10:22.669620084 -0500
@@ -134,8 +134,8 @@ sn2_ipi_flush_all_tlb(struct mm_struct *
 	itc = ia64_get_itc();
 	smp_flush_tlb_cpumask(*mm_cpumask(mm));
 	itc = ia64_get_itc() - itc;
-	__get_cpu_var(ptcstats).shub_ipi_flushes_itc_clocks += itc;
-	__get_cpu_var(ptcstats).shub_ipi_flushes++;
+	__this_cpu_add(ptcstats.shub_ipi_flushes_itc_clocks, itc);
+	__this_cpu_inc(ptcstats.shub_ipi_flushes);
 }
 
 /**
@@ -199,14 +199,14 @@ sn2_global_tlb_purge(struct mm_struct *m
 			start += (1UL << nbits);
 		} while (start < end);
 		ia64_srlz_i();
-		__get_cpu_var(ptcstats).ptc_l++;
+		__this_cpu_inc(ptcstats.ptc_l);
 		preempt_enable();
 		return;
 	}
 
 	if (atomic_read(&mm->mm_users) == 1 && mymm) {
 		flush_tlb_mm(mm);
-		__get_cpu_var(ptcstats).change_rid++;
+		__this_cpu_inc(ptcstats.change_rid);
 		preempt_enable();
 		return;
 	}
@@ -250,11 +250,11 @@ sn2_global_tlb_purge(struct mm_struct *m
 	spin_lock_irqsave(PTC_LOCK(shub1), flags);
 	itc2 = ia64_get_itc();
 
-	__get_cpu_var(ptcstats).lock_itc_clocks += itc2 - itc;
-	__get_cpu_var(ptcstats).shub_ptc_flushes++;
-	__get_cpu_var(ptcstats).nodes_flushed += nix;
+	__this_cpu_add(ptcstats.lock_itc_clocks, itc2 - itc);
+	__this_cpu_inc(ptcstats.shub_ptc_flushes);
+	__this_cpu_add(ptcstats.nodes_flushed, nix);
 	if (!mymm)
-		 __get_cpu_var(ptcstats).shub_ptc_flushes_not_my_mm++;
+		 __this_cpu_inc(ptcstats.shub_ptc_flushes_not_my_mm);
 
 	if (use_cpu_ptcga && !mymm) {
 		old_rr = ia64_get_rr(start);
@@ -299,9 +299,9 @@ sn2_global_tlb_purge(struct mm_struct *m
 
 done:
 	itc2 = ia64_get_itc() - itc2;
-	__get_cpu_var(ptcstats).shub_itc_clocks += itc2;
-	if (itc2 > __get_cpu_var(ptcstats).shub_itc_clocks_max)
-		__get_cpu_var(ptcstats).shub_itc_clocks_max = itc2;
+	__this_cpu_add(ptcstats)shub_itc_clocks, itc2);
+	if (itc2 > __this_cpu_read(ptcstats.shub_itc_clocks_max))
+		__this_cpu_write(ptcstats).shub_itc_clocks_max, itc2);
 
 	if (old_rr) {
 		ia64_set_rr(start, old_rr);
@@ -311,7 +311,7 @@ done:
 	spin_unlock_irqrestore(PTC_LOCK(shub1), flags);
 
 	if (flush_opt == 1 && deadlock) {
-		__get_cpu_var(ptcstats).deadlocks++;
+		__this_cpu_inc(ptcstats.deadlocks);
 		sn2_ipi_flush_all_tlb(mm);
 	}
 
@@ -334,7 +334,7 @@ sn2_ptc_deadlock_recovery(short *nasids,
 	short nasid, i;
 	unsigned long *piows, zeroval, n;
 
-	__get_cpu_var(ptcstats).deadlocks++;
+	__this_cpu_inc(ptcstats.deadlocks);
 
 	piows = (unsigned long *) pda->pio_write_status_addr;
 	zeroval = pda->pio_write_status_val;
@@ -349,7 +349,7 @@ sn2_ptc_deadlock_recovery(short *nasids,
 			ptc1 = CHANGE_NASID(nasid, ptc1);
 
 		n = sn2_ptc_deadlock_recovery_core(ptc0, data0, ptc1, data1, piows, zeroval);
-		__get_cpu_var(ptcstats).deadlocks2 += n;
+		__this_cpu_add(ptcstats.deadlocks2, n);
 	}
 
 }
Index: linux/arch/ia64/include/asm/hw_irq.h
===================================================================
--- linux.orig/arch/ia64/include/asm/hw_irq.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/hw_irq.h	2013-08-23 09:10:22.673620044 -0500
@@ -160,7 +160,7 @@ static inline ia64_vector __ia64_irq_to_
 static inline unsigned int
 __ia64_local_vector_to_irq (ia64_vector vec)
 {
-	return __get_cpu_var(vector_irq)[vec];
+	return __this_cpu_read(vector_irq[vec]);
 }
 #endif
 
Index: linux/arch/ia64/include/asm/sn/nodepda.h
===================================================================
--- linux.orig/arch/ia64/include/asm/sn/nodepda.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/sn/nodepda.h	2013-08-23 09:10:22.673620044 -0500
@@ -70,7 +70,7 @@ typedef struct nodepda_s nodepda_t;
  */
 
 DECLARE_PER_CPU(struct nodepda_s *, __sn_nodepda);
-#define sn_nodepda		(__get_cpu_var(__sn_nodepda))
+#define sn_nodepda		__this_cpu_read(__sn_nodepda)
 #define	NODEPDA(cnodeid)	(sn_nodepda->pernode_pdaindr[cnodeid])
 
 /*
Index: linux/arch/ia64/include/asm/switch_to.h
===================================================================
--- linux.orig/arch/ia64/include/asm/switch_to.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/switch_to.h	2013-08-23 09:10:22.673620044 -0500
@@ -32,7 +32,7 @@ extern void ia64_load_extra (struct task
 
 #ifdef CONFIG_PERFMON
   DECLARE_PER_CPU(unsigned long, pfm_syst_info);
-# define PERFMON_IS_SYSWIDE() (__get_cpu_var(pfm_syst_info) & 0x1)
+# define PERFMON_IS_SYSWIDE() (__this_cpu_read(pfm_syst_info) & 0x1)
 #else
 # define PERFMON_IS_SYSWIDE() (0)
 #endif
Index: linux/arch/ia64/include/asm/sn/arch.h
===================================================================
--- linux.orig/arch/ia64/include/asm/sn/arch.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/sn/arch.h	2013-08-23 09:10:22.673620044 -0500
@@ -57,7 +57,7 @@ struct sn_hub_info_s {
 	u16 nasid_bitmask;
 };
 DECLARE_PER_CPU(struct sn_hub_info_s, __sn_hub_info);
-#define sn_hub_info 	(&__get_cpu_var(__sn_hub_info))
+#define sn_hub_info 	this_cpu_ptr(&__sn_hub_info)
 #define is_shub2()	(sn_hub_info->shub2)
 #define is_shub1()	(sn_hub_info->shub2 == 0)
 
@@ -72,7 +72,7 @@ DECLARE_PER_CPU(struct sn_hub_info_s, __
  * cpu.
  */
 DECLARE_PER_CPU(short, __sn_cnodeid_to_nasid[MAX_COMPACT_NODES]);
-#define sn_cnodeid_to_nasid	(&__get_cpu_var(__sn_cnodeid_to_nasid[0]))
+#define sn_cnodeid_to_nasid	this_cpu_ptr(&__sn_cnodeid_to_nasid[0])
 
 
 extern u8 sn_partition_id;
Index: linux/arch/ia64/include/asm/uv/uv_hub.h
===================================================================
--- linux.orig/arch/ia64/include/asm/uv/uv_hub.h	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/include/asm/uv/uv_hub.h	2013-08-23 09:10:22.673620044 -0500
@@ -108,7 +108,7 @@ struct uv_hub_info_s {
 	unsigned char	n_val;
 };
 DECLARE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
-#define uv_hub_info 		(&__get_cpu_var(__uv_hub_info))
+#define uv_hub_info 		this_cpu_ptr(&__uv_hub_info)
 #define uv_cpu_hub_info(cpu)	(&per_cpu(__uv_hub_info, cpu))
 
 /*
Index: linux/arch/ia64/kernel/traps.c
===================================================================
--- linux.orig/arch/ia64/kernel/traps.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/kernel/traps.c	2013-08-23 09:10:22.673620044 -0500
@@ -299,7 +299,7 @@ handle_fpu_swa (int fp_fault, struct pt_
 
 	if (!(current->thread.flags & IA64_THREAD_FPEMU_NOPRINT))  {
 		unsigned long count, current_jiffies = jiffies;
-		struct fpu_swa_msg *cp = &__get_cpu_var(cpulast);
+		struct fpu_swa_msg *cp = this_cpu_ptr(&cpulast);
 
 		if (unlikely(current_jiffies > cp->time))
 			cp->count = 0;
Index: linux/arch/ia64/xen/time.c
===================================================================
--- linux.orig/arch/ia64/xen/time.c	2013-08-23 09:10:22.673620044 -0500
+++ linux/arch/ia64/xen/time.c	2013-08-23 09:10:22.673620044 -0500
@@ -68,7 +68,7 @@ static void get_runstate_snapshot(struct
 
 	BUG_ON(preemptible());
 
-	state = &__get_cpu_var(xen_runstate);
+	state = this_cpu_ptr(&xen_runstate);
 
 	/*
 	 * The runstate info is always updated by the hypervisor on

[gcv v3 21/35] x86: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/x86/kernel/apic/x2apic_uv_x.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/x2apic_uv_x.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apic/x2apic_uv_x.c	2013-08-27 14:26:16.394772930 -0500
@@ -874,10 +874,10 @@ int uv_handle_nmi(unsigned int reason, s
 		spin_unlock(&uv_blade_info[bid].nmi_lock);
 	}
 
-	if (likely(__get_cpu_var(cpu_last_nmi_count) == uv_blade_info[bid].nmi_count))
+	if (likely(__this_cpu_read(cpu_last_nmi_count) == uv_blade_info[bid].nmi_count))
 		return NMI_DONE;
 
-	__get_cpu_var(cpu_last_nmi_count) = uv_blade_info[bid].nmi_count;
+	__this_cpu_write(cpu_last_nmi_count, uv_blade_info[bid].nmi_count);
 
 	/*
 	 * Use a lock so only one cpu prints at a time.
Index: linux/arch/x86/kernel/cpu/mcheck/mce_intel.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce_intel.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce_intel.c	2013-08-27 14:26:16.394772930 -0500
@@ -86,7 +86,7 @@ void mce_intel_cmci_poll(void)
 {
 	if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE)
 		return;
-	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
 }
 
 void mce_intel_hcpu_update(unsigned long cpu)
@@ -179,7 +179,7 @@ static void intel_threshold_interrupt(vo
 {
 	if (cmci_storm_detect())
 		return;
-	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
 	mce_notify_irq();
 }
 
@@ -190,7 +190,7 @@ static void intel_threshold_interrupt(vo
  */
 static void cmci_discover(int banks)
 {
-	unsigned long *owned = (void *)&__get_cpu_var(mce_banks_owned);
+	unsigned long *owned = (void *)this_cpu_ptr(&mce_banks_owned);
 	unsigned long flags;
 	int i;
 	int bios_wrong_thresh = 0;
@@ -208,7 +208,7 @@ static void cmci_discover(int banks)
 		/* Already owned by someone else? */
 		if (val & MCI_CTL2_CMCI_EN) {
 			clear_bit(i, owned);
-			__clear_bit(i, __get_cpu_var(mce_poll_banks));
+			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
 			continue;
 		}
 
@@ -232,7 +232,7 @@ static void cmci_discover(int banks)
 		/* Did the enable bit stick? -- the bank supports CMCI */
 		if (val & MCI_CTL2_CMCI_EN) {
 			set_bit(i, owned);
-			__clear_bit(i, __get_cpu_var(mce_poll_banks));
+			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
 			/*
 			 * We are able to set thresholds for some banks that
 			 * had a threshold of 0. This means the BIOS has not
@@ -243,7 +243,7 @@ static void cmci_discover(int banks)
 					(val & MCI_CTL2_CMCI_THRESHOLD_MASK))
 				bios_wrong_thresh = 1;
 		} else {
-			WARN_ON(!test_bit(i, __get_cpu_var(mce_poll_banks)));
+			WARN_ON(!test_bit(i, this_cpu_ptr(mce_poll_banks)));
 		}
 	}
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
@@ -267,7 +267,7 @@ void cmci_recheck(void)
 	if (!mce_available(__this_cpu_ptr(&cpu_info)) || !cmci_supported(&banks))
 		return;
 	local_irq_save(flags);
-	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
 	local_irq_restore(flags);
 }
 
@@ -286,13 +286,13 @@ void cmci_clear(void)
 		return;
 	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
 	for (i = 0; i < banks; i++) {
-		if (!test_bit(i, __get_cpu_var(mce_banks_owned)))
+		if (!test_bit(i, this_cpu_ptr(mce_banks_owned)))
 			continue;
 		/* Disable CMCI */
 		rdmsrl(MSR_IA32_MCx_CTL2(i), val);
 		val &= ~MCI_CTL2_CMCI_EN;
 		wrmsrl(MSR_IA32_MCx_CTL2(i), val);
-		__clear_bit(i, __get_cpu_var(mce_banks_owned));
+		__clear_bit(i, this_cpu_ptr(mce_banks_owned));
 	}
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
 }
Index: linux/arch/x86/kernel/irq_64.c
===================================================================
--- linux.orig/arch/x86/kernel/irq_64.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/irq_64.c	2013-08-27 14:26:16.398772895 -0500
@@ -52,13 +52,13 @@ static inline void stack_overflow_check(
 	    regs->sp <= curbase + THREAD_SIZE)
 		return;
 
-	irq_stack_top = (u64)__get_cpu_var(irq_stack_union.irq_stack) +
+	irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
 			STACK_TOP_MARGIN;
-	irq_stack_bottom = (u64)__get_cpu_var(irq_stack_ptr);
+	irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
 	if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
 		return;
 
-	oist = &__get_cpu_var(orig_ist);
+	oist = this_cpu_ptr(&orig_ist);
 	estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
 	estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
 	if (regs->sp >= estack_top && regs->sp <= estack_bottom)
Index: linux/arch/x86/kernel/kvm.c
===================================================================
--- linux.orig/arch/x86/kernel/kvm.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/kvm.c	2013-08-27 14:26:16.398772895 -0500
@@ -242,9 +242,9 @@ u32 kvm_read_and_reset_pf_reason(void)
 {
 	u32 reason = 0;
 
-	if (__get_cpu_var(apf_reason).enabled) {
-		reason = __get_cpu_var(apf_reason).reason;
-		__get_cpu_var(apf_reason).reason = 0;
+	if (__this_cpu_read(apf_reason.enabled)) {
+		reason = __this_cpu_read(apf_reason.reason);
+		__this_cpu_write(apf_reason.reason, 0);
 	}
 
 	return reason;
@@ -315,7 +315,7 @@ static void kvm_guest_apic_eoi_write(u32
 	 * there's no need for lock or memory barriers.
 	 * An optimization barrier is implied in apic write.
 	 */
-	if (__test_and_clear_bit(KVM_PV_EOI_BIT, &__get_cpu_var(kvm_apic_eoi)))
+	if (__test_and_clear_bit(KVM_PV_EOI_BIT, this_cpu_ptr(&kvm_apic_eoi)))
 		return;
 	apic_write(APIC_EOI, APIC_EOI_ACK);
 }
@@ -326,13 +326,13 @@ void kvm_guest_cpu_init(void)
 		return;
 
 	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
-		u64 pa = slow_virt_to_phys(&__get_cpu_var(apf_reason));
+		u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
 
 #ifdef CONFIG_PREEMPT
 		pa |= KVM_ASYNC_PF_SEND_ALWAYS;
 #endif
 		wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED);
-		__get_cpu_var(apf_reason).enabled = 1;
+		__this_cpu_write(apf_reason.enabled, 1);
 		printk(KERN_INFO"KVM setup async PF for cpu %d\n",
 		       smp_processor_id());
 	}
@@ -341,8 +341,8 @@ void kvm_guest_cpu_init(void)
 		unsigned long pa;
 		/* Size alignment is implied but just to make it explicit. */
 		BUILD_BUG_ON(__alignof__(kvm_apic_eoi) < 4);
-		__get_cpu_var(kvm_apic_eoi) = 0;
-		pa = slow_virt_to_phys(&__get_cpu_var(kvm_apic_eoi))
+		__this_cpu_write(kvm_apic_eoi, 0);
+		pa = slow_virt_to_phys(this_cpu_ptr(&kvm_apic_eoi))
 			| KVM_MSR_ENABLED;
 		wrmsrl(MSR_KVM_PV_EOI_EN, pa);
 	}
@@ -353,11 +353,11 @@ void kvm_guest_cpu_init(void)
 
 static void kvm_pv_disable_apf(void)
 {
-	if (!__get_cpu_var(apf_reason).enabled)
+	if (!__this_cpu_read(apf_reason.enabled))
 		return;
 
 	wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
-	__get_cpu_var(apf_reason).enabled = 0;
+	__this_cpu_write(apf_reason.enabled, 0);
 
 	printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
 	       smp_processor_id());
Index: linux/arch/x86/kvm/svm.c
===================================================================
--- linux.orig/arch/x86/kvm/svm.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kvm/svm.c	2013-08-27 14:26:16.398772895 -0500
@@ -654,7 +654,7 @@ static int svm_hardware_enable(void *gar
 
 	if (static_cpu_has(X86_FEATURE_TSCRATEMSR)) {
 		wrmsrl(MSR_AMD64_TSC_RATIO, TSC_RATIO_DEFAULT);
-		__get_cpu_var(current_tsc_ratio) = TSC_RATIO_DEFAULT;
+		__this_cpu_write(current_tsc_ratio, TSC_RATIO_DEFAULT);
 	}
 
 
@@ -1312,8 +1312,8 @@ static void svm_vcpu_load(struct kvm_vcp
 		rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
 
 	if (static_cpu_has(X86_FEATURE_TSCRATEMSR) &&
-	    svm->tsc_ratio != __get_cpu_var(current_tsc_ratio)) {
-		__get_cpu_var(current_tsc_ratio) = svm->tsc_ratio;
+	    svm->tsc_ratio != __this_cpu_read(current_tsc_ratio)) {
+		__this_cpu_write(current_tsc_ratio, svm->tsc_ratio);
 		wrmsrl(MSR_AMD64_TSC_RATIO, svm->tsc_ratio);
 	}
 }
Index: linux/arch/x86/kvm/x86.c
===================================================================
--- linux.orig/arch/x86/kvm/x86.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kvm/x86.c	2013-08-27 14:26:16.402772859 -0500
@@ -1485,7 +1485,7 @@ static int kvm_guest_time_update(struct
 
 	/* Keep irq disabled to prevent changes to the clock */
 	local_irq_save(flags);
-	this_tsc_khz = __get_cpu_var(cpu_tsc_khz);
+	this_tsc_khz = __this_cpu_read(cpu_tsc_khz);
 	if (unlikely(this_tsc_khz == 0)) {
 		local_irq_restore(flags);
 		kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
Index: linux/arch/x86/oprofile/op_model_p4.c
===================================================================
--- linux.orig/arch/x86/oprofile/op_model_p4.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/oprofile/op_model_p4.c	2013-08-27 14:26:16.406772823 -0500
@@ -372,7 +372,7 @@ static unsigned int get_stagger(void)
 {
 #ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-	return cpu != cpumask_first(__get_cpu_var(cpu_sibling_map));
+	return cpu != cpumask_first(this_cpu_ptr(cpu_sibling_map));
 #endif
 	return 0;
 }
Index: linux/arch/x86/xen/enlighten.c
===================================================================
--- linux.orig/arch/x86/xen/enlighten.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/xen/enlighten.c	2013-08-27 14:26:16.406772823 -0500
@@ -817,7 +817,7 @@ static void xen_convert_trap_info(const
 
 void xen_copy_trap_info(struct trap_info *traps)
 {
-	const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
+	const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
 
 	xen_convert_trap_info(desc, traps);
 }
@@ -834,7 +834,7 @@ static void xen_load_idt(const struct de
 
 	spin_lock(&lock);
 
-	__get_cpu_var(idt_desc) = *desc;
+	memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
 
 	xen_convert_trap_info(desc, traps);
 
Index: linux/arch/x86/kernel/apb_timer.c
===================================================================
--- linux.orig/arch/x86/kernel/apb_timer.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apb_timer.c	2013-08-27 14:26:16.406772823 -0500
@@ -146,7 +146,7 @@ static inline int is_apbt_capable(void)
 static int __init apbt_clockevent_register(void)
 {
 	struct sfi_timer_table_entry *mtmr;
-	struct apbt_dev *adev = &__get_cpu_var(cpu_apbt_dev);
+	struct apbt_dev *adev = this_cpu_ptr(&cpu_apbt_dev);
 
 	mtmr = sfi_get_mtmr(APBT_CLOCKEVENT0_NUM);
 	if (mtmr == NULL) {
@@ -200,7 +200,7 @@ void apbt_setup_secondary_clock(void)
 	if (!cpu)
 		return;
 
-	adev = &__get_cpu_var(cpu_apbt_dev);
+	adev = this_cpu_ptr(&cpu_apbt_dev);
 	if (!adev->timer) {
 		adev->timer = dw_apb_clockevent_init(cpu, adev->name,
 			APBT_CLOCKEVENT_RATING, adev_virt_addr(adev),
Index: linux/arch/x86/kernel/apic/apic.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/apic.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apic/apic.c	2013-08-27 14:26:16.406772823 -0500
@@ -546,7 +546,7 @@ static DEFINE_PER_CPU(struct clock_event
  */
 static void setup_APIC_timer(void)
 {
-	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 
 	if (this_cpu_has(X86_FEATURE_ARAT)) {
 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
@@ -681,7 +681,7 @@ calibrate_by_pmtimer(long deltapm, long
 
 static int __init calibrate_APIC_clock(void)
 {
-	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 	void (*real_handler)(struct clock_event_device *dev);
 	unsigned long deltaj;
 	long delta, deltatsc;
Index: linux/arch/x86/kernel/cpu/mcheck/mce-inject.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce-inject.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce-inject.c	2013-08-27 14:26:16.410772787 -0500
@@ -83,7 +83,7 @@ static DEFINE_MUTEX(mce_inject_mutex);
 static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs)
 {
 	int cpu = smp_processor_id();
-	struct mce *m = &__get_cpu_var(injectm);
+	struct mce *m = this_cpu_ptr(&injectm);
 	if (!cpumask_test_cpu(cpu, mce_inject_cpumask))
 		return NMI_DONE;
 	cpumask_clear_cpu(cpu, mce_inject_cpumask);
@@ -97,7 +97,7 @@ static int mce_raise_notify(unsigned int
 static void mce_irq_ipi(void *info)
 {
 	int cpu = smp_processor_id();
-	struct mce *m = &__get_cpu_var(injectm);
+	struct mce *m = this_cpu_ptr(&injectm);
 
 	if (cpumask_test_cpu(cpu, mce_inject_cpumask) &&
 			m->inject_flags & MCJ_EXCEPTION) {
@@ -109,7 +109,7 @@ static void mce_irq_ipi(void *info)
 /* Inject mce on current CPU */
 static int raise_local(void)
 {
-	struct mce *m = &__get_cpu_var(injectm);
+	struct mce *m = this_cpu_ptr(&injectm);
 	int context = MCJ_CTX(m->inject_flags);
 	int ret = 0;
 	int cpu = m->extcpu;
Index: linux/arch/x86/kernel/cpu/mcheck/mce.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce.c	2013-08-27 14:26:16.410772787 -0500
@@ -390,7 +390,7 @@ static u64 mce_rdmsrl(u32 msr)
 
 		if (offset < 0)
 			return 0;
-		return *(u64 *)((char *)&__get_cpu_var(injectm) + offset);
+		return *(u64 *)((char *)this_cpu_ptr(&injectm) + offset);
 	}
 
 	if (rdmsrl_safe(msr, &v)) {
@@ -412,7 +412,7 @@ static void mce_wrmsrl(u32 msr, u64 v)
 		int offset = msr_to_offset(msr);
 
 		if (offset >= 0)
-			*(u64 *)((char *)&__get_cpu_var(injectm) + offset) = v;
+			*(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v;
 		return;
 	}
 	wrmsrl(msr, v);
@@ -468,7 +468,7 @@ static DEFINE_PER_CPU(struct mce_ring, m
 /* Runs with CPU affinity in workqueue */
 static int mce_ring_empty(void)
 {
-	struct mce_ring *r = &__get_cpu_var(mce_ring);
+	struct mce_ring *r = this_cpu_ptr(&mce_ring);
 
 	return r->start == r->end;
 }
@@ -480,7 +480,7 @@ static int mce_ring_get(unsigned long *p
 
 	*pfn = 0;
 	get_cpu();
-	r = &__get_cpu_var(mce_ring);
+	r = this_cpu_ptr(&mce_ring);
 	if (r->start == r->end)
 		goto out;
 	*pfn = r->ring[r->start];
@@ -494,7 +494,7 @@ out:
 /* Always runs in MCE context with preempt off */
 static int mce_ring_add(unsigned long pfn)
 {
-	struct mce_ring *r = &__get_cpu_var(mce_ring);
+	struct mce_ring *r = this_cpu_ptr(&mce_ring);
 	unsigned next;
 
 	next = (r->end + 1) % MCE_RING_SIZE;
@@ -516,7 +516,7 @@ int mce_available(struct cpuinfo_x86 *c)
 static void mce_schedule_work(void)
 {
 	if (!mce_ring_empty())
-		schedule_work(&__get_cpu_var(mce_work));
+		schedule_work(this_cpu_ptr(&mce_work));
 }
 
 DEFINE_PER_CPU(struct irq_work, mce_irq_work);
@@ -541,7 +541,7 @@ static void mce_report_event(struct pt_r
 		return;
 	}
 
-	irq_work_queue(&__get_cpu_var(mce_irq_work));
+	irq_work_queue(this_cpu_ptr(&mce_irq_work));
 }
 
 /*
@@ -1037,7 +1037,7 @@ void do_machine_check(struct pt_regs *re
 
 	mce_gather_info(&m, regs);
 
-	final = &__get_cpu_var(mces_seen);
+	final = this_cpu_ptr(&mces_seen);
 	*final = m;
 
 	memset(valid_banks, 0, sizeof(valid_banks));
@@ -1271,14 +1271,14 @@ static unsigned long (*mce_adjust_timer)
 
 static void mce_timer_fn(unsigned long data)
 {
-	struct timer_list *t = &__get_cpu_var(mce_timer);
+	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned long iv;
 
 	WARN_ON(smp_processor_id() != data);
 
 	if (mce_available(__this_cpu_ptr(&cpu_info))) {
 		machine_check_poll(MCP_TIMESTAMP,
-				&__get_cpu_var(mce_poll_banks));
+				this_cpu_ptr(&mce_poll_banks));
 		mce_intel_cmci_poll();
 	}
 
@@ -1306,7 +1306,7 @@ static void mce_timer_fn(unsigned long d
  */
 void mce_timer_kick(unsigned long interval)
 {
-	struct timer_list *t = &__get_cpu_var(mce_timer);
+	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned long when = jiffies + interval;
 	unsigned long iv = __this_cpu_read(mce_next_interval);
 
@@ -1642,7 +1642,7 @@ static void mce_start_timer(unsigned int
 
 static void __mcheck_cpu_init_timer(void)
 {
-	struct timer_list *t = &__get_cpu_var(mce_timer);
+	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned int cpu = smp_processor_id();
 
 	setup_timer(t, mce_timer_fn, cpu);
@@ -1685,8 +1685,8 @@ void mcheck_cpu_init(struct cpuinfo_x86
 	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_vendor(c);
 	__mcheck_cpu_init_timer();
-	INIT_WORK(&__get_cpu_var(mce_work), mce_process_work);
-	init_irq_work(&__get_cpu_var(mce_irq_work), &mce_irq_work_cb);
+	INIT_WORK(this_cpu_ptr(&mce_work), mce_process_work);
+	init_irq_work(this_cpu_ptr(&mce_irq_work), &mce_irq_work_cb);
 }
 
 /*
Index: linux/arch/x86/kernel/cpu/mcheck/mce_amd.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce_amd.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce_amd.c	2013-08-27 14:26:16.410772787 -0500
@@ -310,7 +310,7 @@ static void amd_threshold_interrupt(void
 			 * event.
 			 */
 			machine_check_poll(MCP_TIMESTAMP,
-					&__get_cpu_var(mce_poll_banks));
+					this_cpu_ptr(&mce_poll_banks));
 
 			if (high & MASK_OVERFLOW_HI) {
 				rdmsrl(address, m.misc);
Index: linux/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event.c	2013-08-27 14:26:16.414772752 -0500
@@ -493,7 +493,7 @@ static int __x86_pmu_event_init(struct p
 
 void x86_pmu_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -511,7 +511,7 @@ void x86_pmu_disable_all(void)
 
 static void x86_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!x86_pmu_initialized())
 		return;
@@ -528,7 +528,7 @@ static void x86_pmu_disable(struct pmu *
 
 void x86_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -874,7 +874,7 @@ static void x86_pmu_start(struct perf_ev
 
 static void x86_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	struct hw_perf_event *hwc;
 	int i, added = cpuc->n_added;
@@ -1023,7 +1023,7 @@ void x86_pmu_enable_event(struct perf_ev
  */
 static int x86_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc;
 	int assign[X86_PMC_IDX_MAX];
 	int n, n0, ret;
@@ -1070,7 +1070,7 @@ out:
 
 static void x86_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = event->hw.idx;
 
 	if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
@@ -1149,7 +1149,7 @@ void perf_event_print_debug(void)
 
 void x86_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
@@ -1171,7 +1171,7 @@ void x86_pmu_stop(struct perf_event *eve
 
 static void x86_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	/*
@@ -1213,7 +1213,7 @@ int x86_pmu_handle_irq(struct pt_regs *r
 	int idx, handled = 0;
 	u64 val;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/*
 	 * Some chipsets need to unmask the LVTPC in a particular spot
@@ -1608,7 +1608,7 @@ static void x86_pmu_cancel_txn(struct pm
  */
 static int x86_pmu_commit_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int assign[X86_PMC_IDX_MAX];
 	int n, ret;
 
Index: linux/arch/x86/kernel/cpu/perf_event_amd.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_amd.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_amd.c	2013-08-27 14:26:16.414772752 -0500
@@ -700,7 +700,7 @@ __init int amd_pmu_init(void)
 
 void amd_pmu_enable_virt(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	cpuc->perf_ctr_virt_mask = 0;
 
@@ -712,7 +712,7 @@ EXPORT_SYMBOL_GPL(amd_pmu_enable_virt);
 
 void amd_pmu_disable_virt(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/*
 	 * We only mask out the Host-only bit so that host-only counting works
Index: linux/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_intel.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_intel.c	2013-08-27 14:26:16.414772752 -0500
@@ -898,7 +898,7 @@ static inline bool intel_pmu_needs_lbr_s
 
 static void intel_pmu_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
 
@@ -911,7 +911,7 @@ static void intel_pmu_disable_all(void)
 
 static void intel_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	intel_pmu_pebs_enable_all();
 	intel_pmu_lbr_enable_all();
@@ -945,7 +945,7 @@ static void intel_pmu_enable_all(int add
  */
 static void intel_pmu_nhm_workaround(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	static const unsigned long nhm_magic[4] = {
 		0x4300B5,
 		0x4300D2,
@@ -1039,7 +1039,7 @@ static void intel_pmu_disable_fixed(stru
 static void intel_pmu_disable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (unlikely(hwc->idx == INTEL_PMC_IDX_FIXED_BTS)) {
 		intel_pmu_disable_bts();
@@ -1102,7 +1102,7 @@ static void intel_pmu_enable_fixed(struc
 static void intel_pmu_enable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (unlikely(hwc->idx == INTEL_PMC_IDX_FIXED_BTS)) {
 		if (!__this_cpu_read(cpu_hw_events.enabled))
@@ -1182,7 +1182,7 @@ static int intel_pmu_handle_irq(struct p
 	u64 status;
 	int handled;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/*
 	 * No known reason to not always do late ACK,
@@ -1600,7 +1600,7 @@ EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
 
 static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
 
 	arr[0].msr = MSR_CORE_PERF_GLOBAL_CTRL;
@@ -1621,7 +1621,7 @@ static struct perf_guest_switch_msr *int
 
 static struct perf_guest_switch_msr *core_guest_get_msrs(int *nr)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
 	int idx;
 
@@ -1655,7 +1655,7 @@ static void core_pmu_enable_event(struct
 
 static void core_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
Index: linux/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_intel_ds.c	2013-08-27 14:26:16.414772752 -0500
@@ -424,7 +424,7 @@ void intel_pmu_enable_bts(u64 config)
 
 void intel_pmu_disable_bts(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long debugctlmsr;
 
 	if (!cpuc->ds)
@@ -441,7 +441,7 @@ void intel_pmu_disable_bts(void)
 
 int intel_pmu_drain_bts_buffer(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct bts_record {
 		u64	from;
@@ -634,7 +634,7 @@ struct event_constraint *intel_pebs_cons
 
 void intel_pmu_pebs_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
@@ -649,7 +649,7 @@ void intel_pmu_pebs_enable(struct perf_e
 
 void intel_pmu_pebs_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
@@ -667,7 +667,7 @@ void intel_pmu_pebs_disable(struct perf_
 
 void intel_pmu_pebs_enable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->pebs_enabled)
 		wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
@@ -675,7 +675,7 @@ void intel_pmu_pebs_enable_all(void)
 
 void intel_pmu_pebs_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->pebs_enabled)
 		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
@@ -683,7 +683,7 @@ void intel_pmu_pebs_disable_all(void)
 
 static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long from = cpuc->lbr_entries[0].from;
 	unsigned long old_to, to = cpuc->lbr_entries[0].to;
 	unsigned long ip = regs->ip;
@@ -766,7 +766,7 @@ static void __intel_pmu_pebs_event(struc
 	 * We cast to pebs_record_nhm to get the load latency data
 	 * if extra_reg MSR_PEBS_LD_LAT_THRESHOLD used
 	 */
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct pebs_record_nhm *pebs = __pebs;
 	struct pebs_record_hsw *pebs_hsw = __pebs;
 	struct perf_sample_data data;
@@ -847,7 +847,7 @@ static void __intel_pmu_pebs_event(struc
 
 static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 	struct pebs_record_core *at, *top;
@@ -889,7 +889,7 @@ static void intel_pmu_drain_pebs_core(st
 static void __intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, void *at,
 					void *top)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct perf_event *event = NULL;
 	u64 status = 0;
@@ -926,7 +926,7 @@ static void __intel_pmu_drain_pebs_nhm(s
 
 static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct pebs_record_nhm *at, *top;
 	int n;
@@ -955,7 +955,7 @@ static void intel_pmu_drain_pebs_nhm(str
 
 static void intel_pmu_drain_pebs_hsw(struct pt_regs *iregs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct pebs_record_hsw *at, *top;
 	int n;
Index: linux/arch/x86/kernel/cpu/perf_event_intel_lbr.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_intel_lbr.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_intel_lbr.c	2013-08-27 14:26:16.418772715 -0500
@@ -133,7 +133,7 @@ static void intel_pmu_lbr_filter(struct
 static void __intel_pmu_lbr_enable(void)
 {
 	u64 debugctl;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->lbr_sel)
 		wrmsrl(MSR_LBR_SELECT, cpuc->lbr_sel->config);
@@ -183,7 +183,7 @@ void intel_pmu_lbr_reset(void)
 
 void intel_pmu_lbr_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!x86_pmu.lbr_nr)
 		return;
@@ -203,7 +203,7 @@ void intel_pmu_lbr_enable(struct perf_ev
 
 void intel_pmu_lbr_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!x86_pmu.lbr_nr)
 		return;
@@ -220,7 +220,7 @@ void intel_pmu_lbr_disable(struct perf_e
 
 void intel_pmu_lbr_enable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->lbr_users)
 		__intel_pmu_lbr_enable();
@@ -228,7 +228,7 @@ void intel_pmu_lbr_enable_all(void)
 
 void intel_pmu_lbr_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->lbr_users)
 		__intel_pmu_lbr_disable();
@@ -319,7 +319,7 @@ static void intel_pmu_lbr_read_64(struct
 
 void intel_pmu_lbr_read(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuc->lbr_users)
 		return;
Index: linux/arch/x86/kernel/cpu/perf_event_knc.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_knc.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_knc.c	2013-08-27 14:26:16.418772715 -0500
@@ -217,7 +217,7 @@ static int knc_pmu_handle_irq(struct pt_
 	int bit, loops;
 	u64 status;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	knc_pmu_disable_all();
 
Index: linux/arch/x86/kernel/cpu/perf_event_p4.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_p4.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_p4.c	2013-08-27 14:26:16.418772715 -0500
@@ -915,7 +915,7 @@ static inline void p4_pmu_disable_event(
 
 static void p4_pmu_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -984,7 +984,7 @@ static void p4_pmu_enable_event(struct p
 
 static void p4_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -1004,7 +1004,7 @@ static int p4_pmu_handle_irq(struct pt_r
 	int idx, handled = 0;
 	u64 val;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 		int overflow;
Index: linux/arch/x86/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/x86/kernel/hw_breakpoint.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/hw_breakpoint.c	2013-08-27 14:26:16.418772715 -0500
@@ -110,7 +110,7 @@ int arch_install_hw_breakpoint(struct pe
 	int i;
 
 	for (i = 0; i < HBP_NUM; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (!*slot) {
 			*slot = bp;
@@ -124,7 +124,7 @@ int arch_install_hw_breakpoint(struct pe
 	set_debugreg(info->address, i);
 	__this_cpu_write(cpu_debugreg[i], info->address);
 
-	dr7 = &__get_cpu_var(cpu_dr7);
+	dr7 = this_cpu_ptr(&cpu_dr7);
 	*dr7 |= encode_dr7(i, info->len, info->type);
 
 	set_debugreg(*dr7, 7);
@@ -148,7 +148,7 @@ void arch_uninstall_hw_breakpoint(struct
 	int i;
 
 	for (i = 0; i < HBP_NUM; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (*slot == bp) {
 			*slot = NULL;
@@ -159,7 +159,7 @@ void arch_uninstall_hw_breakpoint(struct
 	if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot"))
 		return;
 
-	dr7 = &__get_cpu_var(cpu_dr7);
+	dr7 = this_cpu_ptr(&cpu_dr7);
 	*dr7 &= ~__encode_dr7(i, info->len, info->type);
 
 	set_debugreg(*dr7, 7);
Index: linux/arch/x86/kvm/vmx.c
===================================================================
--- linux.orig/arch/x86/kvm/vmx.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kvm/vmx.c	2013-08-27 14:26:16.422772680 -0500
@@ -1513,7 +1513,7 @@ static void reload_tss(void)
 	/*
 	 * VT restores TR but not its size.  Useless.
 	 */
-	struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
+	struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
 	struct desc_struct *descs;
 
 	descs = (void *)gdt->address;
@@ -1559,7 +1559,7 @@ static bool update_transition_efer(struc
 
 static unsigned long segment_base(u16 selector)
 {
-	struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
+	struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
 	struct desc_struct *d;
 	unsigned long table_base;
 	unsigned long v;
@@ -1685,7 +1685,7 @@ static void __vmx_load_host_state(struct
 	 */
 	if (!user_has_fpu() && !vmx->vcpu.guest_fpu_loaded)
 		stts();
-	load_gdt(&__get_cpu_var(host_gdt));
+	load_gdt(this_cpu_ptr(&host_gdt));
 }
 
 static void vmx_load_host_state(struct vcpu_vmx *vmx)
@@ -1715,7 +1715,7 @@ static void vmx_vcpu_load(struct kvm_vcp
 	}
 
 	if (vmx->loaded_vmcs->cpu != cpu) {
-		struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
+		struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
 		unsigned long sysenter_esp;
 
 		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
@@ -2611,7 +2611,7 @@ static int hardware_enable(void *garbage
 		ept_sync_global();
 	}
 
-	native_store_gdt(&__get_cpu_var(host_gdt));
+	native_store_gdt(this_cpu_ptr(&host_gdt));
 
 	return 0;
 }
Index: linux/arch/x86/mm/kmemcheck/kmemcheck.c
===================================================================
--- linux.orig/arch/x86/mm/kmemcheck/kmemcheck.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/mm/kmemcheck/kmemcheck.c	2013-08-27 14:26:16.426772644 -0500
@@ -134,7 +134,7 @@ static DEFINE_PER_CPU(struct kmemcheck_c
 
 bool kmemcheck_active(struct pt_regs *regs)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	return data->balance > 0;
 }
@@ -142,7 +142,7 @@ bool kmemcheck_active(struct pt_regs *re
 /* Save an address that needs to be shown/hidden */
 static void kmemcheck_save_addr(unsigned long addr)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	BUG_ON(data->n_addrs >= ARRAY_SIZE(data->addr));
 	data->addr[data->n_addrs++] = addr;
@@ -150,7 +150,7 @@ static void kmemcheck_save_addr(unsigned
 
 static unsigned int kmemcheck_show_all(void)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 	unsigned int i;
 	unsigned int n;
 
@@ -163,7 +163,7 @@ static unsigned int kmemcheck_show_all(v
 
 static unsigned int kmemcheck_hide_all(void)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 	unsigned int i;
 	unsigned int n;
 
@@ -179,7 +179,7 @@ static unsigned int kmemcheck_hide_all(v
  */
 void kmemcheck_show(struct pt_regs *regs)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	BUG_ON(!irqs_disabled());
 
@@ -220,7 +220,7 @@ void kmemcheck_show(struct pt_regs *regs
  */
 void kmemcheck_hide(struct pt_regs *regs)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 	int n;
 
 	BUG_ON(!irqs_disabled());
@@ -522,7 +522,7 @@ static void kmemcheck_access(struct pt_r
 	const uint8_t *insn_primary;
 	unsigned int size;
 
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	/* Recursive fault -- ouch. */
 	if (data->busy) {
Index: linux/arch/x86/oprofile/nmi_int.c
===================================================================
--- linux.orig/arch/x86/oprofile/nmi_int.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/oprofile/nmi_int.c	2013-08-27 14:26:16.426772644 -0500
@@ -64,11 +64,11 @@ u64 op_x86_get_ctrl(struct op_x86_model_
 static int profile_exceptions_notify(unsigned int val, struct pt_regs *regs)
 {
 	if (ctr_running)
-		model->check_ctrs(regs, &__get_cpu_var(cpu_msrs));
+		model->check_ctrs(regs, this_cpu_ptr(&cpu_msrs));
 	else if (!nmi_enabled)
 		return NMI_DONE;
 	else
-		model->stop(&__get_cpu_var(cpu_msrs));
+		model->stop(this_cpu_ptr(&cpu_msrs));
 	return NMI_HANDLED;
 }
 
@@ -91,7 +91,7 @@ static void nmi_cpu_save_registers(struc
 
 static void nmi_cpu_start(void *dummy)
 {
-	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
+	struct op_msrs const *msrs = this_cpu_ptr(&cpu_msrs);
 	if (!msrs->controls)
 		WARN_ON_ONCE(1);
 	else
@@ -111,7 +111,7 @@ static int nmi_start(void)
 
 static void nmi_cpu_stop(void *dummy)
 {
-	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
+	struct op_msrs const *msrs = this_cpu_ptr(&cpu_msrs);
 	if (!msrs->controls)
 		WARN_ON_ONCE(1);
 	else
Index: linux/arch/x86/platform/uv/uv_time.c
===================================================================
--- linux.orig/arch/x86/platform/uv/uv_time.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/platform/uv/uv_time.c	2013-08-27 14:26:16.426772644 -0500
@@ -365,7 +365,7 @@ __setup("uvrtcevt", uv_enable_evt_rtc);
 
 static __init void uv_rtc_register_clockevents(struct work_struct *dummy)
 {
-	struct clock_event_device *ced = &__get_cpu_var(cpu_ced);
+	struct clock_event_device *ced = this_cpu_ptr(&cpu_ced);
 
 	*ced = clock_event_device_uv;
 	ced->cpumask = cpumask_of(smp_processor_id());
Index: linux/arch/x86/xen/multicalls.c
===================================================================
--- linux.orig/arch/x86/xen/multicalls.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/xen/multicalls.c	2013-08-27 14:26:16.426772644 -0500
@@ -54,7 +54,7 @@ DEFINE_PER_CPU(unsigned long, xen_mc_irq
 
 void xen_mc_flush(void)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct multicall_entry *mc;
 	int ret = 0;
 	unsigned long flags;
@@ -131,7 +131,7 @@ void xen_mc_flush(void)
 
 struct multicall_space __xen_mc_entry(size_t args)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct multicall_space ret;
 	unsigned argidx = roundup(b->argidx, sizeof(u64));
 
@@ -162,7 +162,7 @@ struct multicall_space __xen_mc_entry(si
 
 struct multicall_space xen_mc_extend_args(unsigned long op, size_t size)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct multicall_space ret = { NULL, NULL };
 
 	BUG_ON(preemptible());
@@ -192,7 +192,7 @@ out:
 
 void xen_mc_callback(void (*fn)(void *), void *data)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct callback *cb;
 
 	if (b->cbidx == MC_BATCH) {
Index: linux/arch/x86/xen/time.c
===================================================================
--- linux.orig/arch/x86/xen/time.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/xen/time.c	2013-08-27 14:26:16.426772644 -0500
@@ -80,7 +80,7 @@ static void get_runstate_snapshot(struct
 
 	BUG_ON(preemptible());
 
-	state = &__get_cpu_var(xen_runstate);
+	state = this_cpu_ptr(&xen_runstate);
 
 	/*
 	 * The runstate info is always updated by the hypervisor on
@@ -123,7 +123,7 @@ static void do_stolen_accounting(void)
 
 	WARN_ON(state.state != RUNSTATE_running);
 
-	snap = &__get_cpu_var(xen_runstate_snapshot);
+	snap = this_cpu_ptr(&xen_runstate_snapshot);
 
 	/* work out how much time the VCPU has not been runn*ing*  */
 	runnable = state.time[RUNSTATE_runnable] - snap->time[RUNSTATE_runnable];
@@ -158,7 +158,7 @@ cycle_t xen_clocksource_read(void)
 	cycle_t ret;
 
 	preempt_disable_notrace();
-	src = &__get_cpu_var(xen_vcpu)->time;
+	src = this_cpu_ptr(&xen_vcpu->time);
 	ret = pvclock_clocksource_read(src);
 	preempt_enable_notrace();
 	return ret;
@@ -397,7 +397,7 @@ static DEFINE_PER_CPU(struct xen_clock_e
 
 static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
 {
-	struct clock_event_device *evt = &__get_cpu_var(xen_clock_events).evt;
+	struct clock_event_device *evt = this_cpu_ptr(&xen_clock_events.evt);
 	irqreturn_t ret;
 
 	ret = IRQ_NONE;
@@ -460,7 +460,7 @@ void xen_setup_cpu_clockevents(void)
 {
 	BUG_ON(preemptible());
 
-	clockevents_register_device(&__get_cpu_var(xen_clock_events).evt);
+	clockevents_register_device(this_cpu_ptr(&xen_clock_events.evt));
 }
 
 void xen_timer_resume(void)
Index: linux/arch/x86/include/asm/uv/uv_hub.h
===================================================================
--- linux.orig/arch/x86/include/asm/uv/uv_hub.h	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/include/asm/uv/uv_hub.h	2013-08-27 14:26:16.426772644 -0500
@@ -164,7 +164,7 @@ struct uv_hub_info_s {
 };
 
 DECLARE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
-#define uv_hub_info		(&__get_cpu_var(__uv_hub_info))
+#define uv_hub_info		this_cpu_ptr(&__uv_hub_info)
 #define uv_cpu_hub_info(cpu)	(&per_cpu(__uv_hub_info, cpu))
 
 /*
Index: linux/arch/x86/include/asm/perf_event_p4.h
===================================================================
--- linux.orig/arch/x86/include/asm/perf_event_p4.h	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/include/asm/perf_event_p4.h	2013-08-27 14:26:58.630394675 -0500
@@ -189,7 +189,7 @@ static inline int p4_ht_thread(int cpu)
 {
 #ifdef CONFIG_SMP
 	if (smp_num_siblings == 2)
-		return cpu != cpumask_first(__get_cpu_var(cpu_sibling_map));
+		return cpu != cpumask_first(this_cpu_ptr(cpu_sibling_map));
 #endif
 	return 0;
 }
Index: linux/arch/x86/kernel/apic/x2apic_cluster.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/x2apic_cluster.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apic/x2apic_cluster.c	2013-08-27 14:26:16.430772608 -0500
@@ -43,7 +43,7 @@ __x2apic_send_IPI_mask(const struct cpum
 	 * We are to modify mask, so we need an own copy
 	 * and be sure it's manipulated with irq off.
 	 */
-	ipi_mask_ptr = __raw_get_cpu_var(ipi_mask);
+	ipi_mask_ptr = this_cpu_ptr(ipi_mask);
 	cpumask_copy(ipi_mask_ptr, mask);
 
 	/*

[gcv v3 21/35] x86: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/x86/kernel/apic/x2apic_uv_x.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/x2apic_uv_x.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apic/x2apic_uv_x.c	2013-08-27 14:26:16.394772930 -0500
@@ -874,10 +874,10 @@ int uv_handle_nmi(unsigned int reason, s
 		spin_unlock(&uv_blade_info[bid].nmi_lock);
 	}
 
-	if (likely(__get_cpu_var(cpu_last_nmi_count) == uv_blade_info[bid].nmi_count))
+	if (likely(__this_cpu_read(cpu_last_nmi_count) == uv_blade_info[bid].nmi_count))
 		return NMI_DONE;
 
-	__get_cpu_var(cpu_last_nmi_count) = uv_blade_info[bid].nmi_count;
+	__this_cpu_write(cpu_last_nmi_count, uv_blade_info[bid].nmi_count);
 
 	/*
 	 * Use a lock so only one cpu prints at a time.
Index: linux/arch/x86/kernel/cpu/mcheck/mce_intel.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce_intel.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce_intel.c	2013-08-27 14:26:16.394772930 -0500
@@ -86,7 +86,7 @@ void mce_intel_cmci_poll(void)
 {
 	if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE)
 		return;
-	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
 }
 
 void mce_intel_hcpu_update(unsigned long cpu)
@@ -179,7 +179,7 @@ static void intel_threshold_interrupt(vo
 {
 	if (cmci_storm_detect())
 		return;
-	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
 	mce_notify_irq();
 }
 
@@ -190,7 +190,7 @@ static void intel_threshold_interrupt(vo
  */
 static void cmci_discover(int banks)
 {
-	unsigned long *owned = (void *)&__get_cpu_var(mce_banks_owned);
+	unsigned long *owned = (void *)this_cpu_ptr(&mce_banks_owned);
 	unsigned long flags;
 	int i;
 	int bios_wrong_thresh = 0;
@@ -208,7 +208,7 @@ static void cmci_discover(int banks)
 		/* Already owned by someone else? */
 		if (val & MCI_CTL2_CMCI_EN) {
 			clear_bit(i, owned);
-			__clear_bit(i, __get_cpu_var(mce_poll_banks));
+			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
 			continue;
 		}
 
@@ -232,7 +232,7 @@ static void cmci_discover(int banks)
 		/* Did the enable bit stick? -- the bank supports CMCI */
 		if (val & MCI_CTL2_CMCI_EN) {
 			set_bit(i, owned);
-			__clear_bit(i, __get_cpu_var(mce_poll_banks));
+			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
 			/*
 			 * We are able to set thresholds for some banks that
 			 * had a threshold of 0. This means the BIOS has not
@@ -243,7 +243,7 @@ static void cmci_discover(int banks)
 					(val & MCI_CTL2_CMCI_THRESHOLD_MASK))
 				bios_wrong_thresh = 1;
 		} else {
-			WARN_ON(!test_bit(i, __get_cpu_var(mce_poll_banks)));
+			WARN_ON(!test_bit(i, this_cpu_ptr(mce_poll_banks)));
 		}
 	}
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
@@ -267,7 +267,7 @@ void cmci_recheck(void)
 	if (!mce_available(__this_cpu_ptr(&cpu_info)) || !cmci_supported(&banks))
 		return;
 	local_irq_save(flags);
-	machine_check_poll(MCP_TIMESTAMP, &__get_cpu_var(mce_banks_owned));
+	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
 	local_irq_restore(flags);
 }
 
@@ -286,13 +286,13 @@ void cmci_clear(void)
 		return;
 	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
 	for (i = 0; i < banks; i++) {
-		if (!test_bit(i, __get_cpu_var(mce_banks_owned)))
+		if (!test_bit(i, this_cpu_ptr(mce_banks_owned)))
 			continue;
 		/* Disable CMCI */
 		rdmsrl(MSR_IA32_MCx_CTL2(i), val);
 		val &= ~MCI_CTL2_CMCI_EN;
 		wrmsrl(MSR_IA32_MCx_CTL2(i), val);
-		__clear_bit(i, __get_cpu_var(mce_banks_owned));
+		__clear_bit(i, this_cpu_ptr(mce_banks_owned));
 	}
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
 }
Index: linux/arch/x86/kernel/irq_64.c
===================================================================
--- linux.orig/arch/x86/kernel/irq_64.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/irq_64.c	2013-08-27 14:26:16.398772895 -0500
@@ -52,13 +52,13 @@ static inline void stack_overflow_check(
 	    regs->sp <= curbase + THREAD_SIZE)
 		return;
 
-	irq_stack_top = (u64)__get_cpu_var(irq_stack_union.irq_stack) +
+	irq_stack_top = (u64)this_cpu_ptr(irq_stack_union.irq_stack) +
 			STACK_TOP_MARGIN;
-	irq_stack_bottom = (u64)__get_cpu_var(irq_stack_ptr);
+	irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
 	if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
 		return;
 
-	oist = &__get_cpu_var(orig_ist);
+	oist = this_cpu_ptr(&orig_ist);
 	estack_top = (u64)oist->ist[0] - EXCEPTION_STKSZ + STACK_TOP_MARGIN;
 	estack_bottom = (u64)oist->ist[N_EXCEPTION_STACKS - 1];
 	if (regs->sp >= estack_top && regs->sp <= estack_bottom)
Index: linux/arch/x86/kernel/kvm.c
===================================================================
--- linux.orig/arch/x86/kernel/kvm.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/kvm.c	2013-08-27 14:26:16.398772895 -0500
@@ -242,9 +242,9 @@ u32 kvm_read_and_reset_pf_reason(void)
 {
 	u32 reason = 0;
 
-	if (__get_cpu_var(apf_reason).enabled) {
-		reason = __get_cpu_var(apf_reason).reason;
-		__get_cpu_var(apf_reason).reason = 0;
+	if (__this_cpu_read(apf_reason.enabled)) {
+		reason = __this_cpu_read(apf_reason.reason);
+		__this_cpu_write(apf_reason.reason, 0);
 	}
 
 	return reason;
@@ -315,7 +315,7 @@ static void kvm_guest_apic_eoi_write(u32
 	 * there's no need for lock or memory barriers.
 	 * An optimization barrier is implied in apic write.
 	 */
-	if (__test_and_clear_bit(KVM_PV_EOI_BIT, &__get_cpu_var(kvm_apic_eoi)))
+	if (__test_and_clear_bit(KVM_PV_EOI_BIT, this_cpu_ptr(&kvm_apic_eoi)))
 		return;
 	apic_write(APIC_EOI, APIC_EOI_ACK);
 }
@@ -326,13 +326,13 @@ void kvm_guest_cpu_init(void)
 		return;
 
 	if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF) && kvmapf) {
-		u64 pa = slow_virt_to_phys(&__get_cpu_var(apf_reason));
+		u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
 
 #ifdef CONFIG_PREEMPT
 		pa |= KVM_ASYNC_PF_SEND_ALWAYS;
 #endif
 		wrmsrl(MSR_KVM_ASYNC_PF_EN, pa | KVM_ASYNC_PF_ENABLED);
-		__get_cpu_var(apf_reason).enabled = 1;
+		__this_cpu_write(apf_reason.enabled, 1);
 		printk(KERN_INFO"KVM setup async PF for cpu %d\n",
 		       smp_processor_id());
 	}
@@ -341,8 +341,8 @@ void kvm_guest_cpu_init(void)
 		unsigned long pa;
 		/* Size alignment is implied but just to make it explicit. */
 		BUILD_BUG_ON(__alignof__(kvm_apic_eoi) < 4);
-		__get_cpu_var(kvm_apic_eoi) = 0;
-		pa = slow_virt_to_phys(&__get_cpu_var(kvm_apic_eoi))
+		__this_cpu_write(kvm_apic_eoi, 0);
+		pa = slow_virt_to_phys(this_cpu_ptr(&kvm_apic_eoi))
 			| KVM_MSR_ENABLED;
 		wrmsrl(MSR_KVM_PV_EOI_EN, pa);
 	}
@@ -353,11 +353,11 @@ void kvm_guest_cpu_init(void)
 
 static void kvm_pv_disable_apf(void)
 {
-	if (!__get_cpu_var(apf_reason).enabled)
+	if (!__this_cpu_read(apf_reason.enabled))
 		return;
 
 	wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
-	__get_cpu_var(apf_reason).enabled = 0;
+	__this_cpu_write(apf_reason.enabled, 0);
 
 	printk(KERN_INFO"Unregister pv shared memory for cpu %d\n",
 	       smp_processor_id());
Index: linux/arch/x86/kvm/svm.c
===================================================================
--- linux.orig/arch/x86/kvm/svm.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kvm/svm.c	2013-08-27 14:26:16.398772895 -0500
@@ -654,7 +654,7 @@ static int svm_hardware_enable(void *gar
 
 	if (static_cpu_has(X86_FEATURE_TSCRATEMSR)) {
 		wrmsrl(MSR_AMD64_TSC_RATIO, TSC_RATIO_DEFAULT);
-		__get_cpu_var(current_tsc_ratio) = TSC_RATIO_DEFAULT;
+		__this_cpu_write(current_tsc_ratio, TSC_RATIO_DEFAULT);
 	}
 
 
@@ -1312,8 +1312,8 @@ static void svm_vcpu_load(struct kvm_vcp
 		rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
 
 	if (static_cpu_has(X86_FEATURE_TSCRATEMSR) &&
-	    svm->tsc_ratio != __get_cpu_var(current_tsc_ratio)) {
-		__get_cpu_var(current_tsc_ratio) = svm->tsc_ratio;
+	    svm->tsc_ratio != __this_cpu_read(current_tsc_ratio)) {
+		__this_cpu_write(current_tsc_ratio, svm->tsc_ratio);
 		wrmsrl(MSR_AMD64_TSC_RATIO, svm->tsc_ratio);
 	}
 }
Index: linux/arch/x86/kvm/x86.c
===================================================================
--- linux.orig/arch/x86/kvm/x86.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kvm/x86.c	2013-08-27 14:26:16.402772859 -0500
@@ -1485,7 +1485,7 @@ static int kvm_guest_time_update(struct
 
 	/* Keep irq disabled to prevent changes to the clock */
 	local_irq_save(flags);
-	this_tsc_khz = __get_cpu_var(cpu_tsc_khz);
+	this_tsc_khz = __this_cpu_read(cpu_tsc_khz);
 	if (unlikely(this_tsc_khz == 0)) {
 		local_irq_restore(flags);
 		kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
Index: linux/arch/x86/oprofile/op_model_p4.c
===================================================================
--- linux.orig/arch/x86/oprofile/op_model_p4.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/oprofile/op_model_p4.c	2013-08-27 14:26:16.406772823 -0500
@@ -372,7 +372,7 @@ static unsigned int get_stagger(void)
 {
 #ifdef CONFIG_SMP
 	int cpu = smp_processor_id();
-	return cpu != cpumask_first(__get_cpu_var(cpu_sibling_map));
+	return cpu != cpumask_first(this_cpu_ptr(cpu_sibling_map));
 #endif
 	return 0;
 }
Index: linux/arch/x86/xen/enlighten.c
===================================================================
--- linux.orig/arch/x86/xen/enlighten.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/xen/enlighten.c	2013-08-27 14:26:16.406772823 -0500
@@ -817,7 +817,7 @@ static void xen_convert_trap_info(const
 
 void xen_copy_trap_info(struct trap_info *traps)
 {
-	const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
+	const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
 
 	xen_convert_trap_info(desc, traps);
 }
@@ -834,7 +834,7 @@ static void xen_load_idt(const struct de
 
 	spin_lock(&lock);
 
-	__get_cpu_var(idt_desc) = *desc;
+	memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
 
 	xen_convert_trap_info(desc, traps);
 
Index: linux/arch/x86/kernel/apb_timer.c
===================================================================
--- linux.orig/arch/x86/kernel/apb_timer.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apb_timer.c	2013-08-27 14:26:16.406772823 -0500
@@ -146,7 +146,7 @@ static inline int is_apbt_capable(void)
 static int __init apbt_clockevent_register(void)
 {
 	struct sfi_timer_table_entry *mtmr;
-	struct apbt_dev *adev = &__get_cpu_var(cpu_apbt_dev);
+	struct apbt_dev *adev = this_cpu_ptr(&cpu_apbt_dev);
 
 	mtmr = sfi_get_mtmr(APBT_CLOCKEVENT0_NUM);
 	if (mtmr == NULL) {
@@ -200,7 +200,7 @@ void apbt_setup_secondary_clock(void)
 	if (!cpu)
 		return;
 
-	adev = &__get_cpu_var(cpu_apbt_dev);
+	adev = this_cpu_ptr(&cpu_apbt_dev);
 	if (!adev->timer) {
 		adev->timer = dw_apb_clockevent_init(cpu, adev->name,
 			APBT_CLOCKEVENT_RATING, adev_virt_addr(adev),
Index: linux/arch/x86/kernel/apic/apic.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/apic.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apic/apic.c	2013-08-27 14:26:16.406772823 -0500
@@ -546,7 +546,7 @@ static DEFINE_PER_CPU(struct clock_event
  */
 static void setup_APIC_timer(void)
 {
-	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 
 	if (this_cpu_has(X86_FEATURE_ARAT)) {
 		lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
@@ -681,7 +681,7 @@ calibrate_by_pmtimer(long deltapm, long
 
 static int __init calibrate_APIC_clock(void)
 {
-	struct clock_event_device *levt = &__get_cpu_var(lapic_events);
+	struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
 	void (*real_handler)(struct clock_event_device *dev);
 	unsigned long deltaj;
 	long delta, deltatsc;
Index: linux/arch/x86/kernel/cpu/mcheck/mce-inject.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce-inject.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce-inject.c	2013-08-27 14:26:16.410772787 -0500
@@ -83,7 +83,7 @@ static DEFINE_MUTEX(mce_inject_mutex);
 static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs)
 {
 	int cpu = smp_processor_id();
-	struct mce *m = &__get_cpu_var(injectm);
+	struct mce *m = this_cpu_ptr(&injectm);
 	if (!cpumask_test_cpu(cpu, mce_inject_cpumask))
 		return NMI_DONE;
 	cpumask_clear_cpu(cpu, mce_inject_cpumask);
@@ -97,7 +97,7 @@ static int mce_raise_notify(unsigned int
 static void mce_irq_ipi(void *info)
 {
 	int cpu = smp_processor_id();
-	struct mce *m = &__get_cpu_var(injectm);
+	struct mce *m = this_cpu_ptr(&injectm);
 
 	if (cpumask_test_cpu(cpu, mce_inject_cpumask) &&
 			m->inject_flags & MCJ_EXCEPTION) {
@@ -109,7 +109,7 @@ static void mce_irq_ipi(void *info)
 /* Inject mce on current CPU */
 static int raise_local(void)
 {
-	struct mce *m = &__get_cpu_var(injectm);
+	struct mce *m = this_cpu_ptr(&injectm);
 	int context = MCJ_CTX(m->inject_flags);
 	int ret = 0;
 	int cpu = m->extcpu;
Index: linux/arch/x86/kernel/cpu/mcheck/mce.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce.c	2013-08-27 14:26:16.410772787 -0500
@@ -390,7 +390,7 @@ static u64 mce_rdmsrl(u32 msr)
 
 		if (offset < 0)
 			return 0;
-		return *(u64 *)((char *)&__get_cpu_var(injectm) + offset);
+		return *(u64 *)((char *)this_cpu_ptr(&injectm) + offset);
 	}
 
 	if (rdmsrl_safe(msr, &v)) {
@@ -412,7 +412,7 @@ static void mce_wrmsrl(u32 msr, u64 v)
 		int offset = msr_to_offset(msr);
 
 		if (offset >= 0)
-			*(u64 *)((char *)&__get_cpu_var(injectm) + offset) = v;
+			*(u64 *)((char *)this_cpu_ptr(&injectm) + offset) = v;
 		return;
 	}
 	wrmsrl(msr, v);
@@ -468,7 +468,7 @@ static DEFINE_PER_CPU(struct mce_ring, m
 /* Runs with CPU affinity in workqueue */
 static int mce_ring_empty(void)
 {
-	struct mce_ring *r = &__get_cpu_var(mce_ring);
+	struct mce_ring *r = this_cpu_ptr(&mce_ring);
 
 	return r->start == r->end;
 }
@@ -480,7 +480,7 @@ static int mce_ring_get(unsigned long *p
 
 	*pfn = 0;
 	get_cpu();
-	r = &__get_cpu_var(mce_ring);
+	r = this_cpu_ptr(&mce_ring);
 	if (r->start == r->end)
 		goto out;
 	*pfn = r->ring[r->start];
@@ -494,7 +494,7 @@ out:
 /* Always runs in MCE context with preempt off */
 static int mce_ring_add(unsigned long pfn)
 {
-	struct mce_ring *r = &__get_cpu_var(mce_ring);
+	struct mce_ring *r = this_cpu_ptr(&mce_ring);
 	unsigned next;
 
 	next = (r->end + 1) % MCE_RING_SIZE;
@@ -516,7 +516,7 @@ int mce_available(struct cpuinfo_x86 *c)
 static void mce_schedule_work(void)
 {
 	if (!mce_ring_empty())
-		schedule_work(&__get_cpu_var(mce_work));
+		schedule_work(this_cpu_ptr(&mce_work));
 }
 
 DEFINE_PER_CPU(struct irq_work, mce_irq_work);
@@ -541,7 +541,7 @@ static void mce_report_event(struct pt_r
 		return;
 	}
 
-	irq_work_queue(&__get_cpu_var(mce_irq_work));
+	irq_work_queue(this_cpu_ptr(&mce_irq_work));
 }
 
 /*
@@ -1037,7 +1037,7 @@ void do_machine_check(struct pt_regs *re
 
 	mce_gather_info(&m, regs);
 
-	final = &__get_cpu_var(mces_seen);
+	final = this_cpu_ptr(&mces_seen);
 	*final = m;
 
 	memset(valid_banks, 0, sizeof(valid_banks));
@@ -1271,14 +1271,14 @@ static unsigned long (*mce_adjust_timer)
 
 static void mce_timer_fn(unsigned long data)
 {
-	struct timer_list *t = &__get_cpu_var(mce_timer);
+	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned long iv;
 
 	WARN_ON(smp_processor_id() != data);
 
 	if (mce_available(__this_cpu_ptr(&cpu_info))) {
 		machine_check_poll(MCP_TIMESTAMP,
-				&__get_cpu_var(mce_poll_banks));
+				this_cpu_ptr(&mce_poll_banks));
 		mce_intel_cmci_poll();
 	}
 
@@ -1306,7 +1306,7 @@ static void mce_timer_fn(unsigned long d
  */
 void mce_timer_kick(unsigned long interval)
 {
-	struct timer_list *t = &__get_cpu_var(mce_timer);
+	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned long when = jiffies + interval;
 	unsigned long iv = __this_cpu_read(mce_next_interval);
 
@@ -1642,7 +1642,7 @@ static void mce_start_timer(unsigned int
 
 static void __mcheck_cpu_init_timer(void)
 {
-	struct timer_list *t = &__get_cpu_var(mce_timer);
+	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned int cpu = smp_processor_id();
 
 	setup_timer(t, mce_timer_fn, cpu);
@@ -1685,8 +1685,8 @@ void mcheck_cpu_init(struct cpuinfo_x86
 	__mcheck_cpu_init_generic();
 	__mcheck_cpu_init_vendor(c);
 	__mcheck_cpu_init_timer();
-	INIT_WORK(&__get_cpu_var(mce_work), mce_process_work);
-	init_irq_work(&__get_cpu_var(mce_irq_work), &mce_irq_work_cb);
+	INIT_WORK(this_cpu_ptr(&mce_work), mce_process_work);
+	init_irq_work(this_cpu_ptr(&mce_irq_work), &mce_irq_work_cb);
 }
 
 /*
Index: linux/arch/x86/kernel/cpu/mcheck/mce_amd.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/mcheck/mce_amd.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/mcheck/mce_amd.c	2013-08-27 14:26:16.410772787 -0500
@@ -310,7 +310,7 @@ static void amd_threshold_interrupt(void
 			 * event.
 			 */
 			machine_check_poll(MCP_TIMESTAMP,
-					&__get_cpu_var(mce_poll_banks));
+					this_cpu_ptr(&mce_poll_banks));
 
 			if (high & MASK_OVERFLOW_HI) {
 				rdmsrl(address, m.misc);
Index: linux/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event.c	2013-08-27 14:26:16.414772752 -0500
@@ -493,7 +493,7 @@ static int __x86_pmu_event_init(struct p
 
 void x86_pmu_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -511,7 +511,7 @@ void x86_pmu_disable_all(void)
 
 static void x86_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!x86_pmu_initialized())
 		return;
@@ -528,7 +528,7 @@ static void x86_pmu_disable(struct pmu *
 
 void x86_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -874,7 +874,7 @@ static void x86_pmu_start(struct perf_ev
 
 static void x86_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_event *event;
 	struct hw_perf_event *hwc;
 	int i, added = cpuc->n_added;
@@ -1023,7 +1023,7 @@ void x86_pmu_enable_event(struct perf_ev
  */
 static int x86_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc;
 	int assign[X86_PMC_IDX_MAX];
 	int n, n0, ret;
@@ -1070,7 +1070,7 @@ out:
 
 static void x86_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx = event->hw.idx;
 
 	if (WARN_ON_ONCE(!(event->hw.state & PERF_HES_STOPPED)))
@@ -1149,7 +1149,7 @@ void perf_event_print_debug(void)
 
 void x86_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	if (__test_and_clear_bit(hwc->idx, cpuc->active_mask)) {
@@ -1171,7 +1171,7 @@ void x86_pmu_stop(struct perf_event *eve
 
 static void x86_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int i;
 
 	/*
@@ -1213,7 +1213,7 @@ int x86_pmu_handle_irq(struct pt_regs *r
 	int idx, handled = 0;
 	u64 val;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/*
 	 * Some chipsets need to unmask the LVTPC in a particular spot
@@ -1608,7 +1608,7 @@ static void x86_pmu_cancel_txn(struct pm
  */
 static int x86_pmu_commit_txn(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int assign[X86_PMC_IDX_MAX];
 	int n, ret;
 
Index: linux/arch/x86/kernel/cpu/perf_event_amd.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_amd.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_amd.c	2013-08-27 14:26:16.414772752 -0500
@@ -700,7 +700,7 @@ __init int amd_pmu_init(void)
 
 void amd_pmu_enable_virt(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	cpuc->perf_ctr_virt_mask = 0;
 
@@ -712,7 +712,7 @@ EXPORT_SYMBOL_GPL(amd_pmu_enable_virt);
 
 void amd_pmu_disable_virt(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/*
 	 * We only mask out the Host-only bit so that host-only counting works
Index: linux/arch/x86/kernel/cpu/perf_event_intel.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_intel.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_intel.c	2013-08-27 14:26:16.414772752 -0500
@@ -898,7 +898,7 @@ static inline bool intel_pmu_needs_lbr_s
 
 static void intel_pmu_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
 
@@ -911,7 +911,7 @@ static void intel_pmu_disable_all(void)
 
 static void intel_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	intel_pmu_pebs_enable_all();
 	intel_pmu_lbr_enable_all();
@@ -945,7 +945,7 @@ static void intel_pmu_enable_all(int add
  */
 static void intel_pmu_nhm_workaround(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	static const unsigned long nhm_magic[4] = {
 		0x4300B5,
 		0x4300D2,
@@ -1039,7 +1039,7 @@ static void intel_pmu_disable_fixed(stru
 static void intel_pmu_disable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (unlikely(hwc->idx == INTEL_PMC_IDX_FIXED_BTS)) {
 		intel_pmu_disable_bts();
@@ -1102,7 +1102,7 @@ static void intel_pmu_enable_fixed(struc
 static void intel_pmu_enable_event(struct perf_event *event)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (unlikely(hwc->idx == INTEL_PMC_IDX_FIXED_BTS)) {
 		if (!__this_cpu_read(cpu_hw_events.enabled))
@@ -1182,7 +1182,7 @@ static int intel_pmu_handle_irq(struct p
 	u64 status;
 	int handled;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/*
 	 * No known reason to not always do late ACK,
@@ -1600,7 +1600,7 @@ EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
 
 static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
 
 	arr[0].msr = MSR_CORE_PERF_GLOBAL_CTRL;
@@ -1621,7 +1621,7 @@ static struct perf_guest_switch_msr *int
 
 static struct perf_guest_switch_msr *core_guest_get_msrs(int *nr)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
 	int idx;
 
@@ -1655,7 +1655,7 @@ static void core_pmu_enable_event(struct
 
 static void core_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
Index: linux/arch/x86/kernel/cpu/perf_event_intel_ds.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_intel_ds.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_intel_ds.c	2013-08-27 14:26:16.414772752 -0500
@@ -424,7 +424,7 @@ void intel_pmu_enable_bts(u64 config)
 
 void intel_pmu_disable_bts(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long debugctlmsr;
 
 	if (!cpuc->ds)
@@ -441,7 +441,7 @@ void intel_pmu_disable_bts(void)
 
 int intel_pmu_drain_bts_buffer(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct bts_record {
 		u64	from;
@@ -634,7 +634,7 @@ struct event_constraint *intel_pebs_cons
 
 void intel_pmu_pebs_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
@@ -649,7 +649,7 @@ void intel_pmu_pebs_enable(struct perf_e
 
 void intel_pmu_pebs_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 
 	cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
@@ -667,7 +667,7 @@ void intel_pmu_pebs_disable(struct perf_
 
 void intel_pmu_pebs_enable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->pebs_enabled)
 		wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
@@ -675,7 +675,7 @@ void intel_pmu_pebs_enable_all(void)
 
 void intel_pmu_pebs_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->pebs_enabled)
 		wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
@@ -683,7 +683,7 @@ void intel_pmu_pebs_disable_all(void)
 
 static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	unsigned long from = cpuc->lbr_entries[0].from;
 	unsigned long old_to, to = cpuc->lbr_entries[0].to;
 	unsigned long ip = regs->ip;
@@ -766,7 +766,7 @@ static void __intel_pmu_pebs_event(struc
 	 * We cast to pebs_record_nhm to get the load latency data
 	 * if extra_reg MSR_PEBS_LD_LAT_THRESHOLD used
 	 */
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct pebs_record_nhm *pebs = __pebs;
 	struct pebs_record_hsw *pebs_hsw = __pebs;
 	struct perf_sample_data data;
@@ -847,7 +847,7 @@ static void __intel_pmu_pebs_event(struc
 
 static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct perf_event *event = cpuc->events[0]; /* PMC0 only */
 	struct pebs_record_core *at, *top;
@@ -889,7 +889,7 @@ static void intel_pmu_drain_pebs_core(st
 static void __intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, void *at,
 					void *top)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct perf_event *event = NULL;
 	u64 status = 0;
@@ -926,7 +926,7 @@ static void __intel_pmu_drain_pebs_nhm(s
 
 static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct pebs_record_nhm *at, *top;
 	int n;
@@ -955,7 +955,7 @@ static void intel_pmu_drain_pebs_nhm(str
 
 static void intel_pmu_drain_pebs_hsw(struct pt_regs *iregs)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
 	struct pebs_record_hsw *at, *top;
 	int n;
Index: linux/arch/x86/kernel/cpu/perf_event_intel_lbr.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_intel_lbr.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_intel_lbr.c	2013-08-27 14:26:16.418772715 -0500
@@ -133,7 +133,7 @@ static void intel_pmu_lbr_filter(struct
 static void __intel_pmu_lbr_enable(void)
 {
 	u64 debugctl;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->lbr_sel)
 		wrmsrl(MSR_LBR_SELECT, cpuc->lbr_sel->config);
@@ -183,7 +183,7 @@ void intel_pmu_lbr_reset(void)
 
 void intel_pmu_lbr_enable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!x86_pmu.lbr_nr)
 		return;
@@ -203,7 +203,7 @@ void intel_pmu_lbr_enable(struct perf_ev
 
 void intel_pmu_lbr_disable(struct perf_event *event)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!x86_pmu.lbr_nr)
 		return;
@@ -220,7 +220,7 @@ void intel_pmu_lbr_disable(struct perf_e
 
 void intel_pmu_lbr_enable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->lbr_users)
 		__intel_pmu_lbr_enable();
@@ -228,7 +228,7 @@ void intel_pmu_lbr_enable_all(void)
 
 void intel_pmu_lbr_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->lbr_users)
 		__intel_pmu_lbr_disable();
@@ -319,7 +319,7 @@ static void intel_pmu_lbr_read_64(struct
 
 void intel_pmu_lbr_read(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuc->lbr_users)
 		return;
Index: linux/arch/x86/kernel/cpu/perf_event_knc.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_knc.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_knc.c	2013-08-27 14:26:16.418772715 -0500
@@ -217,7 +217,7 @@ static int knc_pmu_handle_irq(struct pt_
 	int bit, loops;
 	u64 status;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	knc_pmu_disable_all();
 
Index: linux/arch/x86/kernel/cpu/perf_event_p4.c
===================================================================
--- linux.orig/arch/x86/kernel/cpu/perf_event_p4.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/cpu/perf_event_p4.c	2013-08-27 14:26:16.418772715 -0500
@@ -915,7 +915,7 @@ static inline void p4_pmu_disable_event(
 
 static void p4_pmu_disable_all(void)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -984,7 +984,7 @@ static void p4_pmu_enable_event(struct p
 
 static void p4_pmu_enable_all(int added)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	int idx;
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
@@ -1004,7 +1004,7 @@ static int p4_pmu_handle_irq(struct pt_r
 	int idx, handled = 0;
 	u64 val;
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	for (idx = 0; idx < x86_pmu.num_counters; idx++) {
 		int overflow;
Index: linux/arch/x86/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/x86/kernel/hw_breakpoint.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/hw_breakpoint.c	2013-08-27 14:26:16.418772715 -0500
@@ -110,7 +110,7 @@ int arch_install_hw_breakpoint(struct pe
 	int i;
 
 	for (i = 0; i < HBP_NUM; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (!*slot) {
 			*slot = bp;
@@ -124,7 +124,7 @@ int arch_install_hw_breakpoint(struct pe
 	set_debugreg(info->address, i);
 	__this_cpu_write(cpu_debugreg[i], info->address);
 
-	dr7 = &__get_cpu_var(cpu_dr7);
+	dr7 = this_cpu_ptr(&cpu_dr7);
 	*dr7 |= encode_dr7(i, info->len, info->type);
 
 	set_debugreg(*dr7, 7);
@@ -148,7 +148,7 @@ void arch_uninstall_hw_breakpoint(struct
 	int i;
 
 	for (i = 0; i < HBP_NUM; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (*slot == bp) {
 			*slot = NULL;
@@ -159,7 +159,7 @@ void arch_uninstall_hw_breakpoint(struct
 	if (WARN_ONCE(i == HBP_NUM, "Can't find any breakpoint slot"))
 		return;
 
-	dr7 = &__get_cpu_var(cpu_dr7);
+	dr7 = this_cpu_ptr(&cpu_dr7);
 	*dr7 &= ~__encode_dr7(i, info->len, info->type);
 
 	set_debugreg(*dr7, 7);
Index: linux/arch/x86/kvm/vmx.c
===================================================================
--- linux.orig/arch/x86/kvm/vmx.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kvm/vmx.c	2013-08-27 14:26:16.422772680 -0500
@@ -1513,7 +1513,7 @@ static void reload_tss(void)
 	/*
 	 * VT restores TR but not its size.  Useless.
 	 */
-	struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
+	struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
 	struct desc_struct *descs;
 
 	descs = (void *)gdt->address;
@@ -1559,7 +1559,7 @@ static bool update_transition_efer(struc
 
 static unsigned long segment_base(u16 selector)
 {
-	struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
+	struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
 	struct desc_struct *d;
 	unsigned long table_base;
 	unsigned long v;
@@ -1685,7 +1685,7 @@ static void __vmx_load_host_state(struct
 	 */
 	if (!user_has_fpu() && !vmx->vcpu.guest_fpu_loaded)
 		stts();
-	load_gdt(&__get_cpu_var(host_gdt));
+	load_gdt(this_cpu_ptr(&host_gdt));
 }
 
 static void vmx_load_host_state(struct vcpu_vmx *vmx)
@@ -1715,7 +1715,7 @@ static void vmx_vcpu_load(struct kvm_vcp
 	}
 
 	if (vmx->loaded_vmcs->cpu != cpu) {
-		struct desc_ptr *gdt = &__get_cpu_var(host_gdt);
+		struct desc_ptr *gdt = this_cpu_ptr(&host_gdt);
 		unsigned long sysenter_esp;
 
 		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
@@ -2611,7 +2611,7 @@ static int hardware_enable(void *garbage
 		ept_sync_global();
 	}
 
-	native_store_gdt(&__get_cpu_var(host_gdt));
+	native_store_gdt(this_cpu_ptr(&host_gdt));
 
 	return 0;
 }
Index: linux/arch/x86/mm/kmemcheck/kmemcheck.c
===================================================================
--- linux.orig/arch/x86/mm/kmemcheck/kmemcheck.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/mm/kmemcheck/kmemcheck.c	2013-08-27 14:26:16.426772644 -0500
@@ -134,7 +134,7 @@ static DEFINE_PER_CPU(struct kmemcheck_c
 
 bool kmemcheck_active(struct pt_regs *regs)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	return data->balance > 0;
 }
@@ -142,7 +142,7 @@ bool kmemcheck_active(struct pt_regs *re
 /* Save an address that needs to be shown/hidden */
 static void kmemcheck_save_addr(unsigned long addr)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	BUG_ON(data->n_addrs >= ARRAY_SIZE(data->addr));
 	data->addr[data->n_addrs++] = addr;
@@ -150,7 +150,7 @@ static void kmemcheck_save_addr(unsigned
 
 static unsigned int kmemcheck_show_all(void)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 	unsigned int i;
 	unsigned int n;
 
@@ -163,7 +163,7 @@ static unsigned int kmemcheck_show_all(v
 
 static unsigned int kmemcheck_hide_all(void)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 	unsigned int i;
 	unsigned int n;
 
@@ -179,7 +179,7 @@ static unsigned int kmemcheck_hide_all(v
  */
 void kmemcheck_show(struct pt_regs *regs)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	BUG_ON(!irqs_disabled());
 
@@ -220,7 +220,7 @@ void kmemcheck_show(struct pt_regs *regs
  */
 void kmemcheck_hide(struct pt_regs *regs)
 {
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 	int n;
 
 	BUG_ON(!irqs_disabled());
@@ -522,7 +522,7 @@ static void kmemcheck_access(struct pt_r
 	const uint8_t *insn_primary;
 	unsigned int size;
 
-	struct kmemcheck_context *data = &__get_cpu_var(kmemcheck_context);
+	struct kmemcheck_context *data = this_cpu_ptr(&kmemcheck_context);
 
 	/* Recursive fault -- ouch. */
 	if (data->busy) {
Index: linux/arch/x86/oprofile/nmi_int.c
===================================================================
--- linux.orig/arch/x86/oprofile/nmi_int.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/oprofile/nmi_int.c	2013-08-27 14:26:16.426772644 -0500
@@ -64,11 +64,11 @@ u64 op_x86_get_ctrl(struct op_x86_model_
 static int profile_exceptions_notify(unsigned int val, struct pt_regs *regs)
 {
 	if (ctr_running)
-		model->check_ctrs(regs, &__get_cpu_var(cpu_msrs));
+		model->check_ctrs(regs, this_cpu_ptr(&cpu_msrs));
 	else if (!nmi_enabled)
 		return NMI_DONE;
 	else
-		model->stop(&__get_cpu_var(cpu_msrs));
+		model->stop(this_cpu_ptr(&cpu_msrs));
 	return NMI_HANDLED;
 }
 
@@ -91,7 +91,7 @@ static void nmi_cpu_save_registers(struc
 
 static void nmi_cpu_start(void *dummy)
 {
-	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
+	struct op_msrs const *msrs = this_cpu_ptr(&cpu_msrs);
 	if (!msrs->controls)
 		WARN_ON_ONCE(1);
 	else
@@ -111,7 +111,7 @@ static int nmi_start(void)
 
 static void nmi_cpu_stop(void *dummy)
 {
-	struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
+	struct op_msrs const *msrs = this_cpu_ptr(&cpu_msrs);
 	if (!msrs->controls)
 		WARN_ON_ONCE(1);
 	else
Index: linux/arch/x86/platform/uv/uv_time.c
===================================================================
--- linux.orig/arch/x86/platform/uv/uv_time.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/platform/uv/uv_time.c	2013-08-27 14:26:16.426772644 -0500
@@ -365,7 +365,7 @@ __setup("uvrtcevt", uv_enable_evt_rtc);
 
 static __init void uv_rtc_register_clockevents(struct work_struct *dummy)
 {
-	struct clock_event_device *ced = &__get_cpu_var(cpu_ced);
+	struct clock_event_device *ced = this_cpu_ptr(&cpu_ced);
 
 	*ced = clock_event_device_uv;
 	ced->cpumask = cpumask_of(smp_processor_id());
Index: linux/arch/x86/xen/multicalls.c
===================================================================
--- linux.orig/arch/x86/xen/multicalls.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/xen/multicalls.c	2013-08-27 14:26:16.426772644 -0500
@@ -54,7 +54,7 @@ DEFINE_PER_CPU(unsigned long, xen_mc_irq
 
 void xen_mc_flush(void)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct multicall_entry *mc;
 	int ret = 0;
 	unsigned long flags;
@@ -131,7 +131,7 @@ void xen_mc_flush(void)
 
 struct multicall_space __xen_mc_entry(size_t args)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct multicall_space ret;
 	unsigned argidx = roundup(b->argidx, sizeof(u64));
 
@@ -162,7 +162,7 @@ struct multicall_space __xen_mc_entry(si
 
 struct multicall_space xen_mc_extend_args(unsigned long op, size_t size)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct multicall_space ret = { NULL, NULL };
 
 	BUG_ON(preemptible());
@@ -192,7 +192,7 @@ out:
 
 void xen_mc_callback(void (*fn)(void *), void *data)
 {
-	struct mc_buffer *b = &__get_cpu_var(mc_buffer);
+	struct mc_buffer *b = this_cpu_ptr(&mc_buffer);
 	struct callback *cb;
 
 	if (b->cbidx == MC_BATCH) {
Index: linux/arch/x86/xen/time.c
===================================================================
--- linux.orig/arch/x86/xen/time.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/xen/time.c	2013-08-27 14:26:16.426772644 -0500
@@ -80,7 +80,7 @@ static void get_runstate_snapshot(struct
 
 	BUG_ON(preemptible());
 
-	state = &__get_cpu_var(xen_runstate);
+	state = this_cpu_ptr(&xen_runstate);
 
 	/*
 	 * The runstate info is always updated by the hypervisor on
@@ -123,7 +123,7 @@ static void do_stolen_accounting(void)
 
 	WARN_ON(state.state != RUNSTATE_running);
 
-	snap = &__get_cpu_var(xen_runstate_snapshot);
+	snap = this_cpu_ptr(&xen_runstate_snapshot);
 
 	/* work out how much time the VCPU has not been runn*ing*  */
 	runnable = state.time[RUNSTATE_runnable] - snap->time[RUNSTATE_runnable];
@@ -158,7 +158,7 @@ cycle_t xen_clocksource_read(void)
 	cycle_t ret;
 
 	preempt_disable_notrace();
-	src = &__get_cpu_var(xen_vcpu)->time;
+	src = this_cpu_ptr(&xen_vcpu->time);
 	ret = pvclock_clocksource_read(src);
 	preempt_enable_notrace();
 	return ret;
@@ -397,7 +397,7 @@ static DEFINE_PER_CPU(struct xen_clock_e
 
 static irqreturn_t xen_timer_interrupt(int irq, void *dev_id)
 {
-	struct clock_event_device *evt = &__get_cpu_var(xen_clock_events).evt;
+	struct clock_event_device *evt = this_cpu_ptr(&xen_clock_events.evt);
 	irqreturn_t ret;
 
 	ret = IRQ_NONE;
@@ -460,7 +460,7 @@ void xen_setup_cpu_clockevents(void)
 {
 	BUG_ON(preemptible());
 
-	clockevents_register_device(&__get_cpu_var(xen_clock_events).evt);
+	clockevents_register_device(this_cpu_ptr(&xen_clock_events.evt));
 }
 
 void xen_timer_resume(void)
Index: linux/arch/x86/include/asm/uv/uv_hub.h
===================================================================
--- linux.orig/arch/x86/include/asm/uv/uv_hub.h	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/include/asm/uv/uv_hub.h	2013-08-27 14:26:16.426772644 -0500
@@ -164,7 +164,7 @@ struct uv_hub_info_s {
 };
 
 DECLARE_PER_CPU(struct uv_hub_info_s, __uv_hub_info);
-#define uv_hub_info		(&__get_cpu_var(__uv_hub_info))
+#define uv_hub_info		this_cpu_ptr(&__uv_hub_info)
 #define uv_cpu_hub_info(cpu)	(&per_cpu(__uv_hub_info, cpu))
 
 /*
Index: linux/arch/x86/include/asm/perf_event_p4.h
===================================================================
--- linux.orig/arch/x86/include/asm/perf_event_p4.h	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/include/asm/perf_event_p4.h	2013-08-27 14:26:58.630394675 -0500
@@ -189,7 +189,7 @@ static inline int p4_ht_thread(int cpu)
 {
 #ifdef CONFIG_SMP
 	if (smp_num_siblings == 2)
-		return cpu != cpumask_first(__get_cpu_var(cpu_sibling_map));
+		return cpu != cpumask_first(this_cpu_ptr(cpu_sibling_map));
 #endif
 	return 0;
 }
Index: linux/arch/x86/kernel/apic/x2apic_cluster.c
===================================================================
--- linux.orig/arch/x86/kernel/apic/x2apic_cluster.c	2013-08-27 14:26:16.434772572 -0500
+++ linux/arch/x86/kernel/apic/x2apic_cluster.c	2013-08-27 14:26:16.430772608 -0500
@@ -43,7 +43,7 @@ __x2apic_send_IPI_mask(const struct cpum
 	 * We are to modify mask, so we need an own copy
 	 * and be sure it's manipulated with irq off.
 	 */
-	ipi_mask_ptr = __raw_get_cpu_var(ipi_mask);
+	ipi_mask_ptr = this_cpu_ptr(ipi_mask);
 	cpumask_copy(ipi_mask_ptr, mask);
 
 	/*

[gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/arm/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/arm/kernel/hw_breakpoint.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kernel/hw_breakpoint.c	2013-08-26 13:48:40.952795024 -0500
@@ -344,13 +344,13 @@ int arch_install_hw_breakpoint(struct pe
 		/* Breakpoint */
 		ctrl_base = ARM_BASE_BCR;
 		val_base = ARM_BASE_BVR;
-		slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		ctrl_base = ARM_BASE_WCR;
 		val_base = ARM_BASE_WVR;
-		slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 	}
 
@@ -396,12 +396,12 @@ void arch_uninstall_hw_breakpoint(struct
 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		base = ARM_BASE_BCR;
-		slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		base = ARM_BASE_WCR;
-		slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 	}
 
@@ -697,7 +697,7 @@ static void watchpoint_handler(unsigned
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 
 	for (i = 0; i < core_num_wrps; ++i) {
 		rcu_read_lock();
@@ -768,7 +768,7 @@ static void watchpoint_single_step_handl
 	struct perf_event *wp, **slots;
 	struct arch_hw_breakpoint *info;
 
-	slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 
 	for (i = 0; i < core_num_wrps; ++i) {
 		rcu_read_lock();
@@ -802,7 +802,7 @@ static void breakpoint_handler(unsigned
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 
 	/* The exception entry code places the amended lr in the PC. */
 	addr = regs->ARM_pc;
Index: linux/arch/arm/kernel/kprobes.c
===================================================================
--- linux.orig/arch/arm/kernel/kprobes.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kernel/kprobes.c	2013-08-26 13:48:40.952795024 -0500
@@ -171,13 +171,13 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }
 
 static void __kprobes set_current_kprobe(struct kprobe *p)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 static void __kprobes
@@ -421,10 +421,10 @@ static __used __kprobes void *trampoline
 			continue;
 
 		if (ri->rp && ri->rp->handler) {
-			__get_cpu_var(current_kprobe) = &ri->rp->kp;
+			__this_cpu_write(current_kprobe, &ri->rp->kp);
 			get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
 			ri->rp->handler(ri, regs);
-			__get_cpu_var(current_kprobe) = NULL;
+			__this_cpu_write(current_kprobe, NULL);
 		}
 
 		orig_ret_address = (unsigned long)ri->ret_addr;
Index: linux/arch/arm/kernel/perf_event_cpu.c
===================================================================
--- linux.orig/arch/arm/kernel/perf_event_cpu.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kernel/perf_event_cpu.c	2013-08-26 13:48:40.952795024 -0500
@@ -68,7 +68,7 @@ EXPORT_SYMBOL_GPL(perf_num_counters);
 
 static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
 {
-	return &__get_cpu_var(cpu_hw_events);
+	return this_cpu_ptr(&cpu_hw_events);
 }
 
 static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
Index: linux/arch/arm/kvm/arm.c
===================================================================
--- linux.orig/arch/arm/kvm/arm.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kvm/arm.c	2013-08-26 13:48:40.952795024 -0500
@@ -65,7 +65,7 @@ static bool vgic_present;
 static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
 {
 	BUG_ON(preemptible());
-	__get_cpu_var(kvm_arm_running_vcpu) = vcpu;
+	__this_cpu_write(kvm_arm_running_vcpu, vcpu);
 }
 
 /**
@@ -75,7 +75,7 @@ static void kvm_arm_set_running_vcpu(str
 struct kvm_vcpu *kvm_arm_get_running_vcpu(void)
 {
 	BUG_ON(preemptible());
-	return __get_cpu_var(kvm_arm_running_vcpu);
+	return __this_cpu_read(kvm_arm_running_vcpu);
 }
 
 /**
@@ -811,7 +811,7 @@ static void cpu_init_hyp_mode(void *dumm
 
 	boot_pgd_ptr = kvm_mmu_get_boot_httbr();
 	pgd_ptr = kvm_mmu_get_httbr();
-	stack_page = __get_cpu_var(kvm_arm_hyp_stack_page);
+	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);
 	hyp_stack_ptr = stack_page + PAGE_SIZE;
 	vector_ptr = (unsigned long)__kvm_hyp_vector;
 
Index: linux/arch/arm64/kernel/debug-monitors.c
===================================================================
--- linux.orig/arch/arm64/kernel/debug-monitors.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/debug-monitors.c	2013-08-26 13:48:40.952795024 -0500
@@ -98,11 +98,11 @@ void enable_debug_monitors(enum debug_el
 
 	WARN_ON(preemptible());
 
-	if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
+	if (this_cpu_inc_return(mde_ref_count) == 1)
 		enable = DBG_MDSCR_MDE;
 
 	if (el == DBG_ACTIVE_EL1 &&
-	    local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
+	    this_cpu_inc_return(kde_ref_count) == 1)
 		enable |= DBG_MDSCR_KDE;
 
 	if (enable && debug_enabled) {
@@ -118,11 +118,11 @@ void disable_debug_monitors(enum debug_e
 
 	WARN_ON(preemptible());
 
-	if (local_dec_and_test(&__get_cpu_var(mde_ref_count)))
+	if (local_dec_and_test(this_cpu_ptr(&mde_ref_count)))
 		disable = ~DBG_MDSCR_MDE;
 
 	if (el == DBG_ACTIVE_EL1 &&
-	    local_dec_and_test(&__get_cpu_var(kde_ref_count)))
+	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
 		disable &= ~DBG_MDSCR_KDE;
 
 	if (disable) {
Index: linux/arch/arm64/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/arm64/kernel/hw_breakpoint.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/hw_breakpoint.c	2013-08-26 13:48:40.952795024 -0500
@@ -184,14 +184,14 @@ int arch_install_hw_breakpoint(struct pe
 		/* Breakpoint */
 		ctrl_reg = AARCH64_DBG_REG_BCR;
 		val_reg = AARCH64_DBG_REG_BVR;
-		slots = __get_cpu_var(bp_on_reg);
+		slots = __this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 		reg_enable = !debug_info->bps_disabled;
 	} else {
 		/* Watchpoint */
 		ctrl_reg = AARCH64_DBG_REG_WCR;
 		val_reg = AARCH64_DBG_REG_WVR;
-		slots = __get_cpu_var(wp_on_reg);
+		slots = __this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 		reg_enable = !debug_info->wps_disabled;
 	}
@@ -230,12 +230,12 @@ void arch_uninstall_hw_breakpoint(struct
 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		base = AARCH64_DBG_REG_BCR;
-		slots = __get_cpu_var(bp_on_reg);
+		slots = __this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		base = AARCH64_DBG_REG_WCR;
-		slots = __get_cpu_var(wp_on_reg);
+		slots = __this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 	}
 
@@ -505,11 +505,11 @@ static void toggle_bp_registers(int reg,
 
 	switch (reg) {
 	case AARCH64_DBG_REG_BCR:
-		slots = __get_cpu_var(bp_on_reg);
+		slots = __this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 		break;
 	case AARCH64_DBG_REG_WCR:
-		slots = __get_cpu_var(wp_on_reg);
+		slots = __this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 		break;
 	default:
@@ -546,7 +546,7 @@ static int breakpoint_handler(unsigned l
 	struct debug_info *debug_info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 	addr = instruction_pointer(regs);
 	debug_info = &current->thread.debug;
 
@@ -596,7 +596,7 @@ unlock:
 			user_enable_single_step(current);
 	} else {
 		toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL1, 0);
-		kernel_step = &__get_cpu_var(stepping_kernel_bp);
+		kernel_step = this_cpu_ptr(&stepping_kernel_bp);
 
 		if (*kernel_step != ARM_KERNEL_STEP_NONE)
 			return 0;
@@ -623,7 +623,7 @@ static int watchpoint_handler(unsigned l
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 	debug_info = &current->thread.debug;
 
 	for (i = 0; i < core_num_wrps; ++i) {
@@ -698,7 +698,7 @@ unlock:
 			user_enable_single_step(current);
 	} else {
 		toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL1, 0);
-		kernel_step = &__get_cpu_var(stepping_kernel_bp);
+		kernel_step = this_cpu_ptr(&stepping_kernel_bp);
 
 		if (*kernel_step != ARM_KERNEL_STEP_NONE)
 			return 0;
@@ -722,7 +722,7 @@ int reinstall_suspended_bps(struct pt_re
 	struct debug_info *debug_info = &current->thread.debug;
 	int handled_exception = 0, *kernel_step;
 
-	kernel_step = &__get_cpu_var(stepping_kernel_bp);
+	kernel_step = this_cpu_ptr(&stepping_kernel_bp);
 
 	/*
 	 * Called from single-step exception handler.
Index: linux/arch/arm64/kernel/perf_event.c
===================================================================
--- linux.orig/arch/arm64/kernel/perf_event.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/perf_event.c	2013-08-26 13:48:40.952795024 -0500
@@ -1041,7 +1041,7 @@ static irqreturn_t armv8pmu_handle_irq(i
 	 */
 	regs = get_irq_regs();
 
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 	for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
 		struct perf_event *event = cpuc->events[idx];
 		struct hw_perf_event *hwc;
@@ -1254,7 +1254,7 @@ device_initcall(register_pmu_driver);
 
 static struct pmu_hw_events *armpmu_get_cpu_events(void)
 {
-	return &__get_cpu_var(cpu_hw_events);
+	return this_cpu_ptr(&cpu_hw_events);
 }
 
 static void __init cpu_pmu_init(struct arm_pmu *armpmu)

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Russell King - ARM Linux]

On Wed, Aug 28, 2013 at 07:48:23PM +0000, Christoph Lameter wrote:
> 3. Retrieve the content of the current processors instance of a per cpu variable.
> 
> 	DEFINE_PER_CPU(int, u);

Shouldn't this be 'y' ?

> 	int x = __get_cpu_var(y)
> 
>    Converts to
> 
> 	int x = __this_cpu_read(y);
> 
> 
> 4. Retrieve the content of a percpu struct
> 
> 	DEFINE_PER_CPU(struct mystruct, y);
> 	struct mystruct x = __get_cpu_var(y);
> 
>    Converts to
> 
> 	memcpy(this_cpu_ptr(&x), y, sizeof(x));

Are you sure this one's correct?  Isn't 'y' the per-cpu variable?
Even though I don't see any in this patch, it's probably a good thing to
get the patch description correct.

I think you need Will Deacon's ack for this, but I think he's away for
a while.

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 28 Aug 2013, Russell King - ARM Linux wrote:

> On Wed, Aug 28, 2013 at 07:48:23PM +0000, Christoph Lameter wrote:
> > 3. Retrieve the content of the current processors instance of a per cpu variable.
> >
> > 	DEFINE_PER_CPU(int, u);
>
> Shouldn't this be 'y' ?

Right.

> > 	memcpy(this_cpu_ptr(&x), y, sizeof(x));
>
> Are you sure this one's correct?  Isn't 'y' the per-cpu variable?

Also true. Already fixed this once. Sigh.

Description patch:


--- this_x86	2013-08-28 15:35:48.933416126 -0500
+++ patches/this_x86	2013-08-28 15:41:14.386260894 -0500
@@ -26,12 +26,12 @@


 This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
-or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
+or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided
 and less registers are used when code is generated.

-At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.
+At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too.

-The patchset includes passes over all arches as well. Once these operations are used throughout then
+The patch set includes passes over all arches as well. Once these operations are used throughout then
 specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
 f.e. using a global register that may be set to the per cpu base.

@@ -63,7 +63,7 @@

 3. Retrieve the content of the current processors instance of a per cpu variable.

-	DEFINE_PER_CPU(int, u);
+	DEFINE_PER_CPU(int, y);
 	int x = __get_cpu_var(y)

    Converts to
@@ -78,7 +78,7 @@

    Converts to

-	memcpy(this_cpu_ptr(&x), y, sizeof(x));
+	memcpy(&x, this_cpu_ptr(&y), sizeof(x));


 5. Assignment to a per cpu variable

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 28 Aug 2013, Russell King - ARM Linux wrote:

> On Wed, Aug 28, 2013 at 07:48:23PM +0000, Christoph Lameter wrote:
> > 3. Retrieve the content of the current processors instance of a per cpu variable.
> >
> > 	DEFINE_PER_CPU(int, u);
>
> Shouldn't this be 'y' ?

Right.

> > 	memcpy(this_cpu_ptr(&x), y, sizeof(x));
>
> Are you sure this one's correct?  Isn't 'y' the per-cpu variable?

Also true. Already fixed this once. Sigh.

Description patch:


--- this_x86	2013-08-28 15:35:48.933416126 -0500
+++ patches/this_x86	2013-08-28 15:41:14.386260894 -0500
@@ -26,12 +26,12 @@


 This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
-or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
+or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided
 and less registers are used when code is generated.

-At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.
+At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too.

-The patchset includes passes over all arches as well. Once these operations are used throughout then
+The patch set includes passes over all arches as well. Once these operations are used throughout then
 specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
 f.e. using a global register that may be set to the per cpu base.

@@ -63,7 +63,7 @@

 3. Retrieve the content of the current processors instance of a per cpu variable.

-	DEFINE_PER_CPU(int, u);
+	DEFINE_PER_CPU(int, y);
 	int x = __get_cpu_var(y)

    Converts to
@@ -78,7 +78,7 @@

    Converts to

-	memcpy(this_cpu_ptr(&x), y, sizeof(x));
+	memcpy(&x, this_cpu_ptr(&y), sizeof(x));


 5. Assignment to a per cpu variable

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

Hi Christoph,

Sorry for the delay in looking at this, I've been on holiday for a week.
Comments inline.

On Wed, Aug 28, 2013 at 08:48:23PM +0100, Christoph Lameter wrote:
> Transformations done to __get_cpu_var()
> 
> 
> 1. Determine the address of the percpu instance of the current processor.
> 
>         DEFINE_PER_CPU(int, y);
>         int *x = &__get_cpu_var(y);
> 
>     Converts to
> 
>         int *x = this_cpu_ptr(&y);
> 
> 
> 2. Same as #1 but this time an array structure is involved.
> 
>         DEFINE_PER_CPU(int, y[20]);
>         int *x = __get_cpu_var(y);
> 
>     Converts to
> 
>         int *x = this_cpu_ptr(y);

This is the flavour we have for ARM's hw_breakpoint code, where we have an
array of perf_event * instead of int...

> Index: linux/arch/arm/kernel/hw_breakpoint.c
> ===================================================================
> --- linux.orig/arch/arm/kernel/hw_breakpoint.c  2013-08-26 13:48:40.956794980 -0500
> +++ linux/arch/arm/kernel/hw_breakpoint.c       2013-08-26 13:48:40.952795024 -0500
> @@ -344,13 +344,13 @@ int arch_install_hw_breakpoint(struct pe
>                 /* Breakpoint */
>                 ctrl_base = ARM_BASE_BCR;
>                 val_base = ARM_BASE_BVR;
> -               slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
> +               slots = (struct perf_event **)__this_cpu_read(bp_on_reg);

...so I don't think this is quite right, and indeed, we get a bunch of errors
from GCC:

arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
arch/arm/kernel/hw_breakpoint.c:347:33: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’

changing to match your recipe still doesn't work, however:

arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
arch/arm/kernel/hw_breakpoint.c:347:33: error: cast specifies array type

> Index: linux/arch/arm64/kernel/debug-monitors.c
> ===================================================================
> --- linux.orig/arch/arm64/kernel/debug-monitors.c       2013-08-26 13:48:40.956794980 -0500
> +++ linux/arch/arm64/kernel/debug-monitors.c    2013-08-26 13:48:40.952795024 -0500
> @@ -98,11 +98,11 @@ void enable_debug_monitors(enum debug_el
> 
>         WARN_ON(preemptible());
> 
> -       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
> +       if (this_cpu_inc_return(mde_ref_count) == 1)
>                 enable = DBG_MDSCR_MDE;

I'm not sure that this is safe. We rely on local_inc_return to be atomic
with respect to the current CPU, which will end up being a wrapper around
atomic64_inc_return. However, this_cpu_inc_return simply uses a lock, so
other people accessing the count in a different manner (local_dec_and_test
below) may break local atomicity unless we start disabling interrupts or
something horrible like that.
 
>         if (el == DBG_ACTIVE_EL1 &&
> -           local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
> +           this_cpu_inc_return(kde_ref_count) == 1)
>                 enable |= DBG_MDSCR_KDE;
> 
>         if (enable && debug_enabled) {
> @@ -118,11 +118,11 @@ void disable_debug_monitors(enum debug_e
> 
>         WARN_ON(preemptible());
> 
> -       if (local_dec_and_test(&__get_cpu_var(mde_ref_count)))
> +       if (local_dec_and_test(this_cpu_ptr(&mde_ref_count)))
>                 disable = ~DBG_MDSCR_MDE;
> 
>         if (el == DBG_ACTIVE_EL1 &&
> -           local_dec_and_test(&__get_cpu_var(kde_ref_count)))
> +           local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
>                 disable &= ~DBG_MDSCR_KDE;
> 
>         if (disable) {

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 2838 bytes --]

On Fri, 30 Aug 2013, Will Deacon wrote:

> This is the flavour we have for ARM's hw_breakpoint code, where we have an
> array of perf_event * instead of int...
>
> > Index: linux/arch/arm/kernel/hw_breakpoint.c
> > ===================================================================
> > --- linux.orig/arch/arm/kernel/hw_breakpoint.c  2013-08-26 13:48:40.956794980 -0500
> > +++ linux/arch/arm/kernel/hw_breakpoint.c       2013-08-26 13:48:40.952795024 -0500
> > @@ -344,13 +344,13 @@ int arch_install_hw_breakpoint(struct pe
> >                 /* Breakpoint */
> >                 ctrl_base = ARM_BASE_BCR;
> >                 val_base = ARM_BASE_BVR;
> > -               slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
> > +               slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
>
> ...so I don't think this is quite right, and indeed, we get a bunch of errors
> from GCC:
>
> arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
> arch/arm/kernel/hw_breakpoint.c:347:33: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’

Did you apply the first patch of this series which is a bug fix?

> changing to match your recipe still doesn't work, however:
>
> arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
> arch/arm/kernel/hw_breakpoint.c:347:33: error: cast specifies array type

Yep that is the macro bug that was fixed in the first patch.

> >
> >         WARN_ON(preemptible());
> >
> > -       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
> > +       if (this_cpu_inc_return(mde_ref_count) == 1)
> >                 enable = DBG_MDSCR_MDE;
>
> I'm not sure that this is safe. We rely on local_inc_return to be atomic
> with respect to the current CPU, which will end up being a wrapper around
> atomic64_inc_return. However, this_cpu_inc_return simply uses a lock, so
> other people accessing the count in a different manner (local_dec_and_test
> below) may break local atomicity unless we start disabling interrupts or
> something horrible like that.

I do not see any special code for ARM for this_cpu_inc_return. The
fallback solution in the core code is to disable interrupts for the
inc_return and arch/arm/include/asm/percpu.h includes
asm-generic/percpu.h.

Where did you see it using a lock?

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

Hi Christoph,

On Tue, Sep 03, 2013 at 03:39:57PM +0100, Christoph Lameter wrote:
> On Fri, 30 Aug 2013, Will Deacon wrote:
> > ...so I don't think this is quite right, and indeed, we get a bunch of errors
> > from GCC:
> >
> > arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
> > arch/arm/kernel/hw_breakpoint.c:347:33: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> > arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> > arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> > arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> 
> Did you apply the first patch of this series which is a bug fix?

No, sorry, I didn't see that. Do you have a branch anywhere that I can play
with?

> > changing to match your recipe still doesn't work, however:
> >
> > arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
> > arch/arm/kernel/hw_breakpoint.c:347:33: error: cast specifies array type
> 
> Yep that is the macro bug that was fixed in the first patch.

Ok. Sorry for the noise.

> > >
> > >         WARN_ON(preemptible());
> > >
> > > -       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
> > > +       if (this_cpu_inc_return(mde_ref_count) == 1)
> > >                 enable = DBG_MDSCR_MDE;
> >
> > I'm not sure that this is safe. We rely on local_inc_return to be atomic
> > with respect to the current CPU, which will end up being a wrapper around
> > atomic64_inc_return. However, this_cpu_inc_return simply uses a lock, so
> > other people accessing the count in a different manner (local_dec_and_test
> > below) may break local atomicity unless we start disabling interrupts or
> > something horrible like that.
> 
> I do not see any special code for ARM for this_cpu_inc_return. The
> fallback solution in the core code is to disable interrupts for the
> inc_return and arch/arm/include/asm/percpu.h includes
> asm-generic/percpu.h.
> 
> Where did you see it using a lock?

God knows! You're completely right, and we simply disable interrupts which I
somehow misread as taking a lock. However, is it guaranteed that mixing
an atomic64_* access with a this_cpu_inc_return will retain atomicity
between the two? E.g. if you get interrupted during an atomic64_xchg
operation, the interrupt handler issues this_cpu_inc_return, then on return
to the xchg operation it must reissue any reads that had been executed
prior to the interrupt. This should work on ARM/ARM64 (returning from the
interrupt will clear the exclusive monitor) but I don't know about other
architectures.

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

Hi Christoph,

On Tue, Sep 03, 2013 at 03:39:57PM +0100, Christoph Lameter wrote:
> On Fri, 30 Aug 2013, Will Deacon wrote:
> > ...so I don't think this is quite right, and indeed, we get a bunch of errors
> > from GCC:
> >
> > arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
> > arch/arm/kernel/hw_breakpoint.c:347:33: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> > arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> > arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> > arch/arm/kernel/hw_breakpoint.c:347:1: error: incompatible types when assigning to type ‘struct perf_event *[16]’ from type ‘struct perf_event **’
> 
> Did you apply the first patch of this series which is a bug fix?

No, sorry, I didn't see that. Do you have a branch anywhere that I can play
with?

> > changing to match your recipe still doesn't work, however:
> >
> > arch/arm/kernel/hw_breakpoint.c: In function ‘arch_install_hw_breakpoint’:
> > arch/arm/kernel/hw_breakpoint.c:347:33: error: cast specifies array type
> 
> Yep that is the macro bug that was fixed in the first patch.

Ok. Sorry for the noise.

> > >
> > >         WARN_ON(preemptible());
> > >
> > > -       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
> > > +       if (this_cpu_inc_return(mde_ref_count) == 1)
> > >                 enable = DBG_MDSCR_MDE;
> >
> > I'm not sure that this is safe. We rely on local_inc_return to be atomic
> > with respect to the current CPU, which will end up being a wrapper around
> > atomic64_inc_return. However, this_cpu_inc_return simply uses a lock, so
> > other people accessing the count in a different manner (local_dec_and_test
> > below) may break local atomicity unless we start disabling interrupts or
> > something horrible like that.
> 
> I do not see any special code for ARM for this_cpu_inc_return. The
> fallback solution in the core code is to disable interrupts for the
> inc_return and arch/arm/include/asm/percpu.h includes
> asm-generic/percpu.h.
> 
> Where did you see it using a lock?

God knows! You're completely right, and we simply disable interrupts which I
somehow misread as taking a lock. However, is it guaranteed that mixing
an atomic64_* access with a this_cpu_inc_return will retain atomicity
between the two? E.g. if you get interrupted during an atomic64_xchg
operation, the interrupt handler issues this_cpu_inc_return, then on return
to the xchg operation it must reissue any reads that had been executed
prior to the interrupt. This should work on ARM/ARM64 (returning from the
interrupt will clear the exclusive monitor) but I don't know about other
architectures.

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 4 Sep 2013, Will Deacon wrote:

> > Did you apply the first patch of this series which is a bug fix?
>
> No, sorry, I didn't see that. Do you have a branch anywhere that I can play
> with?

It was merged in Linus tree yesterday.

> > I do not see any special code for ARM for this_cpu_inc_return. The
> > fallback solution in the core code is to disable interrupts for the
> > inc_return and arch/arm/include/asm/percpu.h includes
> > asm-generic/percpu.h.
> >
> > Where did you see it using a lock?
>
> God knows! You're completely right, and we simply disable interrupts which I
> somehow misread as taking a lock. However, is it guaranteed that mixing
> an atomic64_* access with a this_cpu_inc_return will retain atomicity
> between the two? E.g. if you get interrupted during an atomic64_xchg
> operation, the interrupt handler issues this_cpu_inc_return, then on return
> to the xchg operation it must reissue any reads that had been executed
> prior to the interrupt. This should work on ARM/ARM64 (returning from the
> interrupt will clear the exclusive monitor) but I don't know about other
> architectures.

You cannot get interrupted during an atomic64_xchg operation. atomic and
this_cpu operations are stricly serialzed since both should be behaving
like single instructions. __this_cpu ops relax that requirement in case
the arch code incurs significant overhead to make that happen. In cases
where we know that preemption/interrupt disable etc takes care of things
__this_cpu ops come into play.

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

On Wed, Sep 04, 2013 at 03:17:09PM +0100, Christoph Lameter wrote:
> On Wed, 4 Sep 2013, Will Deacon wrote:
> > God knows! You're completely right, and we simply disable interrupts which I
> > somehow misread as taking a lock. However, is it guaranteed that mixing
> > an atomic64_* access with a this_cpu_inc_return will retain atomicity
> > between the two? E.g. if you get interrupted during an atomic64_xchg
> > operation, the interrupt handler issues this_cpu_inc_return, then on return
> > to the xchg operation it must reissue any reads that had been executed
> > prior to the interrupt. This should work on ARM/ARM64 (returning from the
> > interrupt will clear the exclusive monitor) but I don't know about other
> > architectures.
> 
> You cannot get interrupted during an atomic64_xchg operation. atomic and
> this_cpu operations are stricly serialzed since both should be behaving
> like single instructions. __this_cpu ops relax that requirement in case
> the arch code incurs significant overhead to make that happen. In cases
> where we know that preemption/interrupt disable etc takes care of things
> __this_cpu ops come into play.

Hmm, why can't you get interrupted during atomic64_xchg? On ARM, we have the
following sequence:

  static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new)
  {
  	u64 result;
  	unsigned long tmp;
  
  	smp_mb();
  
  	__asm__ __volatile__("@ atomic64_xchg\n"
  "1:	ldrexd	%0, %H0, [%3]\n"
  "	strexd	%1, %4, %H4, [%3]\n"
  "	teq	%1, #0\n"
  "	bne	1b"
  	: "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter)
  	: "r" (&ptr->counter), "r" (new)
  	: "cc");
  
  	smp_mb();
  
  	return result;
  }

which relies on interrupts clearing the exclusive monitor to force us back
around the loop in the inline asm. I could imagine other architectures doing
similar, but only detecting the other writer if it used the same
instructions.

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 4 Sep 2013, Will Deacon wrote:

> Hmm, why can't you get interrupted during atomic64_xchg? On ARM, we have the
> following sequence:

AFAICT atomic means one uninterruptible action.

>   static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new)
>   {
>   	u64 result;
>   	unsigned long tmp;
>
>   	smp_mb();
>
>   	__asm__ __volatile__("@ atomic64_xchg\n"
>   "1:	ldrexd	%0, %H0, [%3]\n"
>   "	strexd	%1, %4, %H4, [%3]\n"
>   "	teq	%1, #0\n"
>   "	bne	1b"
>   	: "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter)
>   	: "r" (&ptr->counter), "r" (new)
>   	: "cc");
>
>   	smp_mb();
>
>   	return result;
>   }
>
> which relies on interrupts clearing the exclusive monitor to force us back
> around the loop in the inline asm. I could imagine other architectures doing
> similar, but only detecting the other writer if it used the same
> instructions.

Well I have never done ARM asm but this looks vaguely like a cmpxchg loop?
That would either perform an atomic change or fail and retry?
If so it still fits the definition of atomic. The change or fail operation
is atomic.

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

On Wed, Sep 04, 2013 at 03:54:04PM +0100, Christoph Lameter wrote:
> On Wed, 4 Sep 2013, Will Deacon wrote:
> 
> > Hmm, why can't you get interrupted during atomic64_xchg? On ARM, we have the
> > following sequence:
> 
> AFAICT atomic means one uninterruptible action.

I think it's more subtle than that, but this is all moot for ARM.

> >   static inline u64 atomic64_xchg(atomic64_t *ptr, u64 new)
> >   {
> >   	u64 result;
> >   	unsigned long tmp;
> >
> >   	smp_mb();
> >
> >   	__asm__ __volatile__("@ atomic64_xchg\n"
> >   "1:	ldrexd	%0, %H0, [%3]\n"
> >   "	strexd	%1, %4, %H4, [%3]\n"
> >   "	teq	%1, #0\n"
> >   "	bne	1b"
> >   	: "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter)
> >   	: "r" (&ptr->counter), "r" (new)
> >   	: "cc");
> >
> >   	smp_mb();
> >
> >   	return result;
> >   }
> >
> > which relies on interrupts clearing the exclusive monitor to force us back
> > around the loop in the inline asm. I could imagine other architectures doing
> > similar, but only detecting the other writer if it used the same
> > instructions.
> 
> Well I have never done ARM asm but this looks vaguely like a cmpxchg loop?
> That would either perform an atomic change or fail and retry?

Correct! The strexd instruction can fail if another access clears the
exclusive monitor.

> If so it still fits the definition of atomic. The change or fail operation
> is atomic.

On ARM, yes. I'm worried that there may be an architecture where the change-
or-fail operation would only fail if the access from the interrupt handler
*also* used that change-or-fail instruction, which isn't the case with
this_cpu_inc.

I have no idea if such an architecture exists :)

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 4 Sep 2013, Will Deacon wrote:

> On ARM, yes. I'm worried that there may be an architecture where the change-
> or-fail operation would only fail if the access from the interrupt handler
> *also* used that change-or-fail instruction, which isn't the case with
> this_cpu_inc.
>
> I have no idea if such an architecture exists :)

Atomic operations use atomic_t. this_cpu operations can only use regular
scalars. So the set of variables that are updated by each should be
distinct.

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

On Wed, Sep 04, 2013 at 07:09:04PM +0100, Christoph Lameter wrote:
> On Wed, 4 Sep 2013, Will Deacon wrote:
> 
> > On ARM, yes. I'm worried that there may be an architecture where the change-
> > or-fail operation would only fail if the access from the interrupt handler
> > *also* used that change-or-fail instruction, which isn't the case with
> > this_cpu_inc.
> >
> > I have no idea if such an architecture exists :)
> 
> Atomic operations use atomic_t. this_cpu operations can only use regular
> scalars. So the set of variables that are updated by each should be
> distinct.

Right, except that your patch contained the following hunk:

Index: linux/arch/arm64/kernel/debug-monitors.c
===================================================================
--- linux.orig/arch/arm64/kernel/debug-monitors.c       2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/debug-monitors.c    2013-08-26 13:48:40.952795024 -0500
@@ -98,11 +98,11 @@ void enable_debug_monitors(enum debug_el

        WARN_ON(preemptible());

-       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
+       if (this_cpu_inc_return(mde_ref_count) == 1)
                enable = DBG_MDSCR_MDE;

        if (el == DBG_ACTIVE_EL1 &&
-           local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
+           this_cpu_inc_return(kde_ref_count) == 1)
                enable |= DBG_MDSCR_KDE;

        if (enable && debug_enabled) {


Then we have:

#define local_inc_return(l) atomic_long_inc_return(&(l)->a)

static inline long atomic_long_inc_return(atomic_long_t *l)
{
	atomic_t *v = (atomic_t *)l;

	return (long)atomic_inc_return(v);
}


So that casting lets the two interfaces overlap (and indeed they do after
your patch, since local_dec_and_test is still used to the same variable).

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

On Wed, Sep 04, 2013 at 07:09:04PM +0100, Christoph Lameter wrote:
> On Wed, 4 Sep 2013, Will Deacon wrote:
> 
> > On ARM, yes. I'm worried that there may be an architecture where the change-
> > or-fail operation would only fail if the access from the interrupt handler
> > *also* used that change-or-fail instruction, which isn't the case with
> > this_cpu_inc.
> >
> > I have no idea if such an architecture exists :)
> 
> Atomic operations use atomic_t. this_cpu operations can only use regular
> scalars. So the set of variables that are updated by each should be
> distinct.

Right, except that your patch contained the following hunk:

Index: linux/arch/arm64/kernel/debug-monitors.c
===================================================================
--- linux.orig/arch/arm64/kernel/debug-monitors.c       2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/debug-monitors.c    2013-08-26 13:48:40.952795024 -0500
@@ -98,11 +98,11 @@ void enable_debug_monitors(enum debug_el

        WARN_ON(preemptible());

-       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
+       if (this_cpu_inc_return(mde_ref_count) == 1)
                enable = DBG_MDSCR_MDE;

        if (el == DBG_ACTIVE_EL1 &&
-           local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
+           this_cpu_inc_return(kde_ref_count) == 1)
                enable |= DBG_MDSCR_KDE;

        if (enable && debug_enabled) {


Then we have:

#define local_inc_return(l) atomic_long_inc_return(&(l)->a)

static inline long atomic_long_inc_return(atomic_long_t *l)
{
	atomic_t *v = (atomic_t *)l;

	return (long)atomic_inc_return(v);
}


So that casting lets the two interfaces overlap (and indeed they do after
your patch, since local_dec_and_test is still used to the same variable).

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Wed, 4 Sep 2013, Will Deacon wrote:

> > Atomic operations use atomic_t. this_cpu operations can only use regular
> > scalars. So the set of variables that are updated by each should be
> > distinct.
>
> Right, except that your patch contained the following hunk:
>
> Index: linux/arch/arm64/kernel/debug-monitors.c
> ===================================================================
> --- linux.orig/arch/arm64/kernel/debug-monitors.c       2013-08-26 13:48:40.956794980 -0500
> +++ linux/arch/arm64/kernel/debug-monitors.c    2013-08-26 13:48:40.952795024 -0500
> @@ -98,11 +98,11 @@ void enable_debug_monitors(enum debug_el
>
>         WARN_ON(preemptible());
>
> -       if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
> +       if (this_cpu_inc_return(mde_ref_count) == 1)
>                 enable = DBG_MDSCR_MDE;
>
>         if (el == DBG_ACTIVE_EL1 &&
> -           local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
> +           this_cpu_inc_return(kde_ref_count) == 1)
>                 enable |= DBG_MDSCR_KDE;
>
>         if (enable && debug_enabled) {
>
>
> Then we have:
>
> #define local_inc_return(l) atomic_long_inc_return(&(l)->a)
>
> static inline long atomic_long_inc_return(atomic_long_t *l)
> {
> 	atomic_t *v = (atomic_t *)l;
>
> 	return (long)atomic_inc_return(v);
> }
>
>
> So that casting lets the two interfaces overlap (and indeed they do after
> your patch, since local_dec_and_test is still used to the same variable).


Ok that is indeed wrong. You would have to switch out the whole treatment
of the variable to consistently use this_cpu ops.

Lets convert the &__get_cpu_vars to the this_cpu_ptr(& xxx )
form. This is almost an this_cpu_xx op but not quite ;-). Looks strange.


Fixed up patch:

Subject: arm: Replace __get_cpu_var uses
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calculations are avoided
and less registers are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so the macro is removed too.

The patch set includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/arch/arm/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/arm/kernel/hw_breakpoint.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kernel/hw_breakpoint.c	2013-08-26 13:48:40.952795024 -0500
@@ -344,13 +344,13 @@ int arch_install_hw_breakpoint(struct pe
 		/* Breakpoint */
 		ctrl_base = ARM_BASE_BCR;
 		val_base = ARM_BASE_BVR;
-		slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		ctrl_base = ARM_BASE_WCR;
 		val_base = ARM_BASE_WVR;
-		slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 	}

@@ -396,12 +396,12 @@ void arch_uninstall_hw_breakpoint(struct
 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		base = ARM_BASE_BCR;
-		slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		base = ARM_BASE_WCR;
-		slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+		slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 	}

@@ -697,7 +697,7 @@ static void watchpoint_handler(unsigned
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;

-	slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);

 	for (i = 0; i < core_num_wrps; ++i) {
 		rcu_read_lock();
@@ -768,7 +768,7 @@ static void watchpoint_single_step_handl
 	struct perf_event *wp, **slots;
 	struct arch_hw_breakpoint *info;

-	slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);

 	for (i = 0; i < core_num_wrps; ++i) {
 		rcu_read_lock();
@@ -802,7 +802,7 @@ static void breakpoint_handler(unsigned
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;

-	slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(bp_on_reg);

 	/* The exception entry code places the amended lr in the PC. */
 	addr = regs->ARM_pc;
Index: linux/arch/arm/kernel/kprobes.c
===================================================================
--- linux.orig/arch/arm/kernel/kprobes.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kernel/kprobes.c	2013-08-26 13:48:40.952795024 -0500
@@ -171,13 +171,13 @@ static void __kprobes save_previous_kpro

 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }

 static void __kprobes set_current_kprobe(struct kprobe *p)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }

 static void __kprobes
@@ -421,10 +421,10 @@ static __used __kprobes void *trampoline
 			continue;

 		if (ri->rp && ri->rp->handler) {
-			__get_cpu_var(current_kprobe) = &ri->rp->kp;
+			__this_cpu_write(current_kprobe, &ri->rp->kp);
 			get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
 			ri->rp->handler(ri, regs);
-			__get_cpu_var(current_kprobe) = NULL;
+			__this_cpu_write(current_kprobe, NULL);
 		}

 		orig_ret_address = (unsigned long)ri->ret_addr;
Index: linux/arch/arm/kernel/perf_event_cpu.c
===================================================================
--- linux.orig/arch/arm/kernel/perf_event_cpu.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kernel/perf_event_cpu.c	2013-08-26 13:48:40.952795024 -0500
@@ -68,7 +68,7 @@ EXPORT_SYMBOL_GPL(perf_num_counters);

 static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
 {
-	return &__get_cpu_var(cpu_hw_events);
+	return this_cpu_ptr(&cpu_hw_events);
 }

 static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
Index: linux/arch/arm/kvm/arm.c
===================================================================
--- linux.orig/arch/arm/kvm/arm.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm/kvm/arm.c	2013-08-26 13:48:40.952795024 -0500
@@ -65,7 +65,7 @@ static bool vgic_present;
 static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
 {
 	BUG_ON(preemptible());
-	__get_cpu_var(kvm_arm_running_vcpu) = vcpu;
+	__this_cpu_write(kvm_arm_running_vcpu, vcpu);
 }

 /**
@@ -75,7 +75,7 @@ static void kvm_arm_set_running_vcpu(str
 struct kvm_vcpu *kvm_arm_get_running_vcpu(void)
 {
 	BUG_ON(preemptible());
-	return __get_cpu_var(kvm_arm_running_vcpu);
+	return __this_cpu_read(kvm_arm_running_vcpu);
 }

 /**
@@ -811,7 +811,7 @@ static void cpu_init_hyp_mode(void *dumm

 	boot_pgd_ptr = kvm_mmu_get_boot_httbr();
 	pgd_ptr = kvm_mmu_get_httbr();
-	stack_page = __get_cpu_var(kvm_arm_hyp_stack_page);
+	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);
 	hyp_stack_ptr = stack_page + PAGE_SIZE;
 	vector_ptr = (unsigned long)__kvm_hyp_vector;

Index: linux/arch/arm64/kernel/debug-monitors.c
===================================================================
--- linux.orig/arch/arm64/kernel/debug-monitors.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/debug-monitors.c	2013-08-26 13:48:40.952795024 -0500
@@ -98,11 +98,11 @@ void enable_debug_monitors(enum debug_el

 	WARN_ON(preemptible());

-	if (local_inc_return(&__get_cpu_var(mde_ref_count)) == 1)
+	if (local_inc_return(this_cpu_ptr(&mde_ref_count)) == 1)
 		enable = DBG_MDSCR_MDE;

 	if (el == DBG_ACTIVE_EL1 &&
-	    local_inc_return(&__get_cpu_var(kde_ref_count)) == 1)
+	    local_inc_return(this_cpu_ptr(&kde_ref_count)) == 1)
 		enable |= DBG_MDSCR_KDE;

 	if (enable && debug_enabled) {
@@ -118,11 +118,11 @@ void disable_debug_monitors(enum debug_e

 	WARN_ON(preemptible());

-	if (local_dec_and_test(&__get_cpu_var(mde_ref_count)))
+	if (local_dec_and_test(this_cpu_ptr(&mde_ref_count)))
 		disable = ~DBG_MDSCR_MDE;

 	if (el == DBG_ACTIVE_EL1 &&
-	    local_dec_and_test(&__get_cpu_var(kde_ref_count)))
+	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
 		disable &= ~DBG_MDSCR_KDE;

 	if (disable) {
Index: linux/arch/arm64/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/arm64/kernel/hw_breakpoint.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/hw_breakpoint.c	2013-08-26 13:48:40.952795024 -0500
@@ -184,14 +184,14 @@ int arch_install_hw_breakpoint(struct pe
 		/* Breakpoint */
 		ctrl_reg = AARCH64_DBG_REG_BCR;
 		val_reg = AARCH64_DBG_REG_BVR;
-		slots = __get_cpu_var(bp_on_reg);
+		slots = __this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 		reg_enable = !debug_info->bps_disabled;
 	} else {
 		/* Watchpoint */
 		ctrl_reg = AARCH64_DBG_REG_WCR;
 		val_reg = AARCH64_DBG_REG_WVR;
-		slots = __get_cpu_var(wp_on_reg);
+		slots = __this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 		reg_enable = !debug_info->wps_disabled;
 	}
@@ -230,12 +230,12 @@ void arch_uninstall_hw_breakpoint(struct
 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		base = AARCH64_DBG_REG_BCR;
-		slots = __get_cpu_var(bp_on_reg);
+		slots = __this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		base = AARCH64_DBG_REG_WCR;
-		slots = __get_cpu_var(wp_on_reg);
+		slots = __this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 	}

@@ -505,11 +505,11 @@ static void toggle_bp_registers(int reg,

 	switch (reg) {
 	case AARCH64_DBG_REG_BCR:
-		slots = __get_cpu_var(bp_on_reg);
+		slots = __this_cpu_read(bp_on_reg);
 		max_slots = core_num_brps;
 		break;
 	case AARCH64_DBG_REG_WCR:
-		slots = __get_cpu_var(wp_on_reg);
+		slots = __this_cpu_read(wp_on_reg);
 		max_slots = core_num_wrps;
 		break;
 	default:
@@ -546,7 +546,7 @@ static int breakpoint_handler(unsigned l
 	struct debug_info *debug_info;
 	struct arch_hw_breakpoint_ctrl ctrl;

-	slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
 	addr = instruction_pointer(regs);
 	debug_info = &current->thread.debug;

@@ -596,7 +596,7 @@ unlock:
 			user_enable_single_step(current);
 	} else {
 		toggle_bp_registers(AARCH64_DBG_REG_BCR, DBG_ACTIVE_EL1, 0);
-		kernel_step = &__get_cpu_var(stepping_kernel_bp);
+		kernel_step = this_cpu_ptr(&stepping_kernel_bp);

 		if (*kernel_step != ARM_KERNEL_STEP_NONE)
 			return 0;
@@ -623,7 +623,7 @@ static int watchpoint_handler(unsigned l
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;

-	slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
 	debug_info = &current->thread.debug;

 	for (i = 0; i < core_num_wrps; ++i) {
@@ -698,7 +698,7 @@ unlock:
 			user_enable_single_step(current);
 	} else {
 		toggle_bp_registers(AARCH64_DBG_REG_WCR, DBG_ACTIVE_EL1, 0);
-		kernel_step = &__get_cpu_var(stepping_kernel_bp);
+		kernel_step = this_cpu_ptr(&stepping_kernel_bp);

 		if (*kernel_step != ARM_KERNEL_STEP_NONE)
 			return 0;
@@ -722,7 +722,7 @@ int reinstall_suspended_bps(struct pt_re
 	struct debug_info *debug_info = &current->thread.debug;
 	int handled_exception = 0, *kernel_step;

-	kernel_step = &__get_cpu_var(stepping_kernel_bp);
+	kernel_step = this_cpu_ptr(&stepping_kernel_bp);

 	/*
 	 * Called from single-step exception handler.
Index: linux/arch/arm64/kernel/perf_event.c
===================================================================
--- linux.orig/arch/arm64/kernel/perf_event.c	2013-08-26 13:48:40.956794980 -0500
+++ linux/arch/arm64/kernel/perf_event.c	2013-08-26 13:48:40.952795024 -0500
@@ -1041,7 +1041,7 @@ static irqreturn_t armv8pmu_handle_irq(i
 	 */
 	regs = get_irq_regs();

-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 	for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
 		struct perf_event *event = cpuc->events[idx];
 		struct hw_perf_event *hwc;
@@ -1254,7 +1254,7 @@ device_initcall(register_pmu_driver);

 static struct pmu_hw_events *armpmu_get_cpu_events(void)
 {
-	return &__get_cpu_var(cpu_hw_events);
+	return this_cpu_ptr(&cpu_hw_events);
 }

 static void __init cpu_pmu_init(struct arm_pmu *armpmu)

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

Here is a patch to be applied after the earlier one to convert the local_t
use to this_cpu. Not sure if I got the local_dec_and_test conversion
right.


Index: linux/arch/arm64/kernel/debug-monitors.c
===================================================================
--- linux.orig/arch/arm64/kernel/debug-monitors.c	2013-09-04 15:53:53.374943378 -0500
+++ linux/arch/arm64/kernel/debug-monitors.c	2013-09-04 15:57:19.564792739 -0500
@@ -27,7 +27,6 @@
 #include <linux/uaccess.h>

 #include <asm/debug-monitors.h>
-#include <asm/local.h>
 #include <asm/cputype.h>
 #include <asm/system_misc.h>

@@ -89,8 +88,8 @@ early_param("nodebugmon", early_debug_di
  * Keep track of debug users on each core.
  * The ref counts are per-cpu so we use a local_t type.
  */
-static DEFINE_PER_CPU(local_t, mde_ref_count);
-static DEFINE_PER_CPU(local_t, kde_ref_count);
+static DEFINE_PER_CPU(int, mde_ref_count);
+static DEFINE_PER_CPU(int, kde_ref_count);

 void enable_debug_monitors(enum debug_el el)
 {
@@ -98,11 +97,11 @@ void enable_debug_monitors(enum debug_el

 	WARN_ON(preemptible());

-	if (local_inc_return(this_cpu_ptr(&mde_ref_count)) == 1)
+	if (this_cpu_inc_return(mde_ref_count) == 1)
 		enable = DBG_MDSCR_MDE;

 	if (el == DBG_ACTIVE_EL1 &&
-	    local_inc_return(this_cpu_ptr(&kde_ref_count)) == 1)
+	    this_cpu_inc_return(kde_ref_count) == 1)
 		enable |= DBG_MDSCR_KDE;

 	if (enable && debug_enabled) {
@@ -118,11 +117,11 @@ void disable_debug_monitors(enum debug_e

 	WARN_ON(preemptible());

-	if (local_dec_and_test(this_cpu_ptr(&mde_ref_count)))
+	if (this_cpu_dec_return(mde_ref_count))
 		disable = ~DBG_MDSCR_MDE;

 	if (el == DBG_ACTIVE_EL1 &&
-	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
+	    this_cpu_dec_return(kde_ref_count))
 		disable &= ~DBG_MDSCR_KDE;

 	if (disable) {

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

Hi again Christoph,

On Wed, Sep 04, 2013 at 09:58:31PM +0100, Christoph Lameter wrote:
> Here is a patch to be applied after the earlier one to convert the local_t
> use to this_cpu. Not sure if I got the local_dec_and_test conversion
> right.

[...]

> @@ -118,11 +117,11 @@ void disable_debug_monitors(enum debug_e
> 
>  	WARN_ON(preemptible());
> 
> -	if (local_dec_and_test(this_cpu_ptr(&mde_ref_count)))
> +	if (this_cpu_dec_return(mde_ref_count))
>  		disable = ~DBG_MDSCR_MDE;
> 
>  	if (el == DBG_ACTIVE_EL1 &&
> -	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
> +	    this_cpu_dec_return(kde_ref_count))
>  		disable &= ~DBG_MDSCR_KDE;

Almost! I think we just need an '== 0' check on the result from the
decrement, since local_dec_and_test is simply a way to check that we've
decremented to zero, so this patch would otherwise invert the meaning.

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

Hi again Christoph,

On Wed, Sep 04, 2013 at 09:58:31PM +0100, Christoph Lameter wrote:
> Here is a patch to be applied after the earlier one to convert the local_t
> use to this_cpu. Not sure if I got the local_dec_and_test conversion
> right.

[...]

> @@ -118,11 +117,11 @@ void disable_debug_monitors(enum debug_e
> 
>  	WARN_ON(preemptible());
> 
> -	if (local_dec_and_test(this_cpu_ptr(&mde_ref_count)))
> +	if (this_cpu_dec_return(mde_ref_count))
>  		disable = ~DBG_MDSCR_MDE;
> 
>  	if (el == DBG_ACTIVE_EL1 &&
> -	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
> +	    this_cpu_dec_return(kde_ref_count))
>  		disable &= ~DBG_MDSCR_KDE;

Almost! I think we just need an '== 0' check on the result from the
decrement, since local_dec_and_test is simply a way to check that we've
decremented to zero, so this patch would otherwise invert the meaning.

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 5 Sep 2013, Will Deacon wrote:

> >
> >  	if (el == DBG_ACTIVE_EL1 &&
> > -	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
> > +	    this_cpu_dec_return(kde_ref_count))
> >  		disable &= ~DBG_MDSCR_KDE;
>
> Almost! I think we just need an '== 0' check on the result from the
> decrement, since local_dec_and_test is simply a way to check that we've
> decremented to zero, so this patch would otherwise invert the meaning.

Ok can you take it from here and modify it? I have no build and test
environment set up for ARM.

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

On Thu, Sep 05, 2013 at 03:24:25PM +0100, Christoph Lameter wrote:
> On Thu, 5 Sep 2013, Will Deacon wrote:
> 
> > >
> > >  	if (el == DBG_ACTIVE_EL1 &&
> > > -	    local_dec_and_test(this_cpu_ptr(&kde_ref_count)))
> > > +	    this_cpu_dec_return(kde_ref_count))
> > >  		disable &= ~DBG_MDSCR_KDE;
> >
> > Almost! I think we just need an '== 0' check on the result from the
> > decrement, since local_dec_and_test is simply a way to check that we've
> > decremented to zero, so this patch would otherwise invert the meaning.
> 
> Ok can you take it from here and modify it? I have no build and test
> environment set up for ARM.

Sure. Does that include the original arm/arm64 patches from your v3 series
as well as these two fixups?

Will

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Thu, 5 Sep 2013, Will Deacon wrote:

> > Ok can you take it from here and modify it? I have no build and test
> > environment set up for ARM.
>
> Sure. Does that include the original arm/arm64 patches from your v3 series
> as well as these two fixups?

I think so. Take whatever you can and I will make another pass after the
merge and pick up anything that was missed.

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Will Deacon]

On Thu, Sep 05, 2013 at 06:52:19PM +0100, Christoph Lameter wrote:
> On Thu, 5 Sep 2013, Will Deacon wrote:
> 
> > > Ok can you take it from here and modify it? I have no build and test
> > > environment set up for ARM.
> >
> > Sure. Does that include the original arm/arm64 patches from your v3 series
> > as well as these two fixups?
> 
> I think so. Take whatever you can and I will make another pass after the
> merge and pick up anything that was missed.

Ok, I had a crack at putting something together on top of HEAD, but I still
see some errors due to pcpu array types (even with your patch in mainline).
I think some of your conversions to __this_cpu_read should use this_cpu_ptr
instead, but could you have a quick look at my fixup below please?

Will

--->8

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index e7e6eca..3d44660 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -344,13 +344,13 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 		/* Breakpoint */
 		ctrl_base = ARM_BASE_BCR;
 		val_base = ARM_BASE_BVR;
-		slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
+		slots = this_cpu_ptr(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		ctrl_base = ARM_BASE_WCR;
 		val_base = ARM_BASE_WVR;
-		slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
+		slots = this_cpu_ptr(wp_on_reg);
 		max_slots = core_num_wrps;
 	}
 
@@ -396,12 +396,12 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		base = ARM_BASE_BCR;
-		slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
+		slots = this_cpu_ptr(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		base = ARM_BASE_WCR;
-		slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
+		slots = this_cpu_ptr(wp_on_reg);
 		max_slots = core_num_wrps;
 	}
 
@@ -697,7 +697,7 @@ static void watchpoint_handler(unsigned long addr, unsigned int fsr,
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
+	slots = this_cpu_ptr(wp_on_reg);
 
 	for (i = 0; i < core_num_wrps; ++i) {
 		rcu_read_lock();
@@ -768,7 +768,7 @@ static void watchpoint_single_step_handler(unsigned long pc)
 	struct perf_event *wp, **slots;
 	struct arch_hw_breakpoint *info;
 
-	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
+	slots = this_cpu_ptr(wp_on_reg);
 
 	for (i = 0; i < core_num_wrps; ++i) {
 		rcu_read_lock();
@@ -802,7 +802,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
+	slots = this_cpu_ptr(bp_on_reg);
 
 	/* The exception entry code places the amended lr in the PC. */
 	addr = regs->ARM_pc;
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index 53dc018..ff516f6 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -184,14 +184,14 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 		/* Breakpoint */
 		ctrl_reg = AARCH64_DBG_REG_BCR;
 		val_reg = AARCH64_DBG_REG_BVR;
-		slots = __this_cpu_read(bp_on_reg);
+		slots = this_cpu_ptr(bp_on_reg);
 		max_slots = core_num_brps;
 		reg_enable = !debug_info->bps_disabled;
 	} else {
 		/* Watchpoint */
 		ctrl_reg = AARCH64_DBG_REG_WCR;
 		val_reg = AARCH64_DBG_REG_WVR;
-		slots = __this_cpu_read(wp_on_reg);
+		slots = this_cpu_ptr(wp_on_reg);
 		max_slots = core_num_wrps;
 		reg_enable = !debug_info->wps_disabled;
 	}
@@ -230,12 +230,12 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
 		/* Breakpoint */
 		base = AARCH64_DBG_REG_BCR;
-		slots = __this_cpu_read(bp_on_reg);
+		slots = this_cpu_ptr(bp_on_reg);
 		max_slots = core_num_brps;
 	} else {
 		/* Watchpoint */
 		base = AARCH64_DBG_REG_WCR;
-		slots = __this_cpu_read(wp_on_reg);
+		slots = this_cpu_ptr(wp_on_reg);
 		max_slots = core_num_wrps;
 	}
 
@@ -505,11 +505,11 @@ static void toggle_bp_registers(int reg, enum debug_el el, int enable)
 
 	switch (reg) {
 	case AARCH64_DBG_REG_BCR:
-		slots = __this_cpu_read(bp_on_reg);
+		slots = this_cpu_ptr(bp_on_reg);
 		max_slots = core_num_brps;
 		break;
 	case AARCH64_DBG_REG_WCR:
-		slots = __this_cpu_read(wp_on_reg);
+		slots = this_cpu_ptr(wp_on_reg);
 		max_slots = core_num_wrps;
 		break;
 	default:
@@ -546,7 +546,7 @@ static int breakpoint_handler(unsigned long unused, unsigned int esr,
 	struct debug_info *debug_info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__this_cpu_read(bp_on_reg);
+	slots = this_cpu_ptr(bp_on_reg);
 	addr = instruction_pointer(regs);
 	debug_info = &current->thread.debug;
 
@@ -623,7 +623,7 @@ static int watchpoint_handler(unsigned long addr, unsigned int esr,
 	struct arch_hw_breakpoint *info;
 	struct arch_hw_breakpoint_ctrl ctrl;
 
-	slots = (struct perf_event **)__this_cpu_read(wp_on_reg);
+	slots = this_cpu_ptr(wp_on_reg);
 	debug_info = &current->thread.debug;
 
 	for (i = 0; i < core_num_wrps; ++i) {

Re: [gcv v3 27/35] arm: Replace __get_cpu_var uses

[Christoph Lameter]

On Fri, 6 Sep 2013, Will Deacon wrote:

> Ok, I had a crack at putting something together on top of HEAD, but I still
> see some errors due to pcpu array types (even with your patch in mainline).
> I think some of your conversions to __this_cpu_read should use this_cpu_ptr
> instead, but could you have a quick look at my fixup below please?

That could be the case since the cocci script does assume a read operation
is needed if there was no & in front of the __get_cpu_var. This is wrong
for pointers and arrays.

Patch looks fine to me.

[gcv v3 30/35] alpha: Replace __get_cpu_var

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)




Index: linux/arch/alpha/kernel/perf_event.c
===================================================================
--- linux.orig/arch/alpha/kernel/perf_event.c	2013-08-26 13:55:35.904436503 -0500
+++ linux/arch/alpha/kernel/perf_event.c	2013-08-26 13:55:35.896436587 -0500
@@ -422,7 +422,7 @@ static void maybe_change_configuration(s
  */
 static int alpha_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int n0;
 	int ret;
@@ -474,7 +474,7 @@ static int alpha_pmu_add(struct perf_eve
  */
 static void alpha_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	unsigned long irq_flags;
 	int j;
@@ -522,7 +522,7 @@ static void alpha_pmu_read(struct perf_e
 static void alpha_pmu_stop(struct perf_event *event, int flags)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!(hwc->state & PERF_HES_STOPPED)) {
 		cpuc->idx_mask &= ~(1UL<<hwc->idx);
@@ -542,7 +542,7 @@ static void alpha_pmu_stop(struct perf_e
 static void alpha_pmu_start(struct perf_event *event, int flags)
 {
 	struct hw_perf_event *hwc = &event->hw;
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
 		return;
@@ -713,7 +713,7 @@ static int alpha_pmu_event_init(struct p
  */
 static void alpha_pmu_enable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (cpuc->enabled)
 		return;
@@ -739,7 +739,7 @@ static void alpha_pmu_enable(struct pmu
 
 static void alpha_pmu_disable(struct pmu *pmu)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	if (!cpuc->enabled)
 		return;
@@ -804,7 +804,7 @@ static void alpha_perf_event_irq_handler
 	int idx, j;
 
 	__this_cpu_inc(irq_pmi_count);
-	cpuc = &__get_cpu_var(cpu_hw_events);
+	cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	/* Completely counting through the PMC's period to trigger a new PMC
 	 * overflow interrupt while in this interrupt routine is utterly
Index: linux/arch/alpha/kernel/time.c
===================================================================
--- linux.orig/arch/alpha/kernel/time.c	2013-08-26 13:55:35.904436503 -0500
+++ linux/arch/alpha/kernel/time.c	2013-08-26 13:55:35.896436587 -0500
@@ -86,9 +86,9 @@ unsigned long est_cycle_freq;
 
 DEFINE_PER_CPU(u8, irq_work_pending);
 
-#define set_irq_work_pending_flag()  __get_cpu_var(irq_work_pending) = 1
-#define test_irq_work_pending()      __get_cpu_var(irq_work_pending)
-#define clear_irq_work_pending()     __get_cpu_var(irq_work_pending) = 0
+#define set_irq_work_pending_flag()  __this_cpu_write(irq_work_pending, 1)
+#define test_irq_work_pending()      __this_cpu_read(irq_work_pending)
+#define clear_irq_work_pending()     __this_cpu_writeirq_work_pending, 0)
 
 void arch_irq_work_raise(void)
 {

[gcv v3 33/35] parisc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Index: linux/arch/parisc/lib/memcpy.c
===================================================================
--- linux.orig/arch/parisc/lib/memcpy.c	2013-08-26 13:28:53.000000000 -0500
+++ linux/arch/parisc/lib/memcpy.c	2013-08-26 13:30:41.656224744 -0500
@@ -470,7 +470,7 @@ static unsigned long pa_memcpy(void *dst
 		return 0;
 
 	/* if a load or store fault occured we can get the faulty addr */
-	d = &__get_cpu_var(exception_data);
+	d = this_cpu_ptr(&exception_data);
 	fault_addr = d->fault_addr;
 
 	/* error in load or store? */
Index: linux/arch/parisc/mm/fault.c
===================================================================
--- linux.orig/arch/parisc/mm/fault.c	2013-08-26 13:28:53.000000000 -0500
+++ linux/arch/parisc/mm/fault.c	2013-08-26 13:30:41.656224744 -0500
@@ -145,7 +145,7 @@ int fixup_exception(struct pt_regs *regs
 	fix = search_exception_tables(regs->iaoq[0]);
 	if (fix) {
 		struct exception_data *d;
-		d = &__get_cpu_var(exception_data);
+		d = this_cpu_ptr(&exception_data);
 		d->fault_ip = regs->iaoq[0];
 		d->fault_space = regs->isr;
 		d->fault_addr = regs->ior;

[gcv v3 33/35] parisc: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Index: linux/arch/parisc/lib/memcpy.c
===================================================================
--- linux.orig/arch/parisc/lib/memcpy.c	2013-08-26 13:28:53.000000000 -0500
+++ linux/arch/parisc/lib/memcpy.c	2013-08-26 13:30:41.656224744 -0500
@@ -470,7 +470,7 @@ static unsigned long pa_memcpy(void *dst
 		return 0;
 
 	/* if a load or store fault occured we can get the faulty addr */
-	d = &__get_cpu_var(exception_data);
+	d = this_cpu_ptr(&exception_data);
 	fault_addr = d->fault_addr;
 
 	/* error in load or store? */
Index: linux/arch/parisc/mm/fault.c
===================================================================
--- linux.orig/arch/parisc/mm/fault.c	2013-08-26 13:28:53.000000000 -0500
+++ linux/arch/parisc/mm/fault.c	2013-08-26 13:30:41.656224744 -0500
@@ -145,7 +145,7 @@ int fixup_exception(struct pt_regs *regs
 	fix = search_exception_tables(regs->iaoq[0]);
 	if (fix) {
 		struct exception_data *d;
-		d = &__get_cpu_var(exception_data);
+		d = this_cpu_ptr(&exception_data);
 		d->fault_ip = regs->iaoq[0];
 		d->fault_space = regs->isr;
 		d->fault_addr = regs->ior;

[gcv v3 15/35] drivers/cpuidle: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/cpuidle/governors/ladder.c
===================================================================
--- linux.orig/drivers/cpuidle/governors/ladder.c	2013-08-27 14:31:00.000000000 -0500
+++ linux/drivers/cpuidle/governors/ladder.c	2013-08-27 14:34:26.170362548 -0500
@@ -66,7 +66,7 @@ static inline void ladder_do_selection(s
 static int ladder_select_state(struct cpuidle_driver *drv,
 				struct cpuidle_device *dev)
 {
-	struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
 	struct ladder_device_state *last_state;
 	int last_residency, last_idx = ldev->last_state_idx;
 	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
@@ -170,7 +170,7 @@ static int ladder_enable_device(struct c
  */
 static void ladder_reflect(struct cpuidle_device *dev, int index)
 {
-	struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
 	if (index > 0)
 		ldev->last_state_idx = index;
 }
Index: linux/drivers/cpuidle/governors/menu.c
===================================================================
--- linux.orig/drivers/cpuidle/governors/menu.c	2013-08-27 14:31:00.000000000 -0500
+++ linux/drivers/cpuidle/governors/menu.c	2013-08-27 14:34:26.170362548 -0500
@@ -258,7 +258,7 @@ again:
  */
 static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
-	struct menu_device *data = &__get_cpu_var(menu_devices);
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
 	int i;
 	int multiplier;
@@ -342,7 +342,7 @@ static int menu_select(struct cpuidle_dr
  */
 static void menu_reflect(struct cpuidle_device *dev, int index)
 {
-	struct menu_device *data = &__get_cpu_var(menu_devices);
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	data->last_state_idx = index;
 	if (index >= 0)
 		data->needs_update = 1;
@@ -355,7 +355,7 @@ static void menu_reflect(struct cpuidle_
  */
 static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
-	struct menu_device *data = &__get_cpu_var(menu_devices);
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	int last_idx = data->last_state_idx;
 	unsigned int last_idle_us = cpuidle_get_last_residency(dev);
 	struct cpuidle_state *target = &drv->states[last_idx];

[gcv v3 15/35] drivers/cpuidle: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)



Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/cpuidle/governors/ladder.c
===================================================================
--- linux.orig/drivers/cpuidle/governors/ladder.c	2013-08-27 14:31:00.000000000 -0500
+++ linux/drivers/cpuidle/governors/ladder.c	2013-08-27 14:34:26.170362548 -0500
@@ -66,7 +66,7 @@ static inline void ladder_do_selection(s
 static int ladder_select_state(struct cpuidle_driver *drv,
 				struct cpuidle_device *dev)
 {
-	struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
 	struct ladder_device_state *last_state;
 	int last_residency, last_idx = ldev->last_state_idx;
 	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
@@ -170,7 +170,7 @@ static int ladder_enable_device(struct c
  */
 static void ladder_reflect(struct cpuidle_device *dev, int index)
 {
-	struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
 	if (index > 0)
 		ldev->last_state_idx = index;
 }
Index: linux/drivers/cpuidle/governors/menu.c
===================================================================
--- linux.orig/drivers/cpuidle/governors/menu.c	2013-08-27 14:31:00.000000000 -0500
+++ linux/drivers/cpuidle/governors/menu.c	2013-08-27 14:34:26.170362548 -0500
@@ -258,7 +258,7 @@ again:
  */
 static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
-	struct menu_device *data = &__get_cpu_var(menu_devices);
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
 	int i;
 	int multiplier;
@@ -342,7 +342,7 @@ static int menu_select(struct cpuidle_dr
  */
 static void menu_reflect(struct cpuidle_device *dev, int index)
 {
-	struct menu_device *data = &__get_cpu_var(menu_devices);
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	data->last_state_idx = index;
 	if (index >= 0)
 		data->needs_update = 1;
@@ -355,7 +355,7 @@ static void menu_reflect(struct cpuidle_
  */
 static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 {
-	struct menu_device *data = &__get_cpu_var(menu_devices);
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
 	int last_idx = data->last_state_idx;
 	unsigned int last_idle_us = cpuidle_get_last_residency(dev);
 	struct cpuidle_state *target = &drv->states[last_idx];

[gcv v3 31/35] sh: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)





Index: linux/arch/sh/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/sh/kernel/hw_breakpoint.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/hw_breakpoint.c	2013-08-26 13:28:32.265604741 -0500
@@ -52,7 +52,7 @@ int arch_install_hw_breakpoint(struct pe
 	int i;
 
 	for (i = 0; i < sh_ubc->num_events; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (!*slot) {
 			*slot = bp;
@@ -84,7 +84,7 @@ void arch_uninstall_hw_breakpoint(struct
 	int i;
 
 	for (i = 0; i < sh_ubc->num_events; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (*slot == bp) {
 			*slot = NULL;
Index: linux/arch/sh/kernel/kprobes.c
===================================================================
--- linux.orig/arch/sh/kernel/kprobes.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/kprobes.c	2013-08-26 13:28:32.265604741 -0500
@@ -102,7 +102,7 @@ int __kprobes kprobe_handle_illslot(unsi
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)
 {
-	struct kprobe *saved = &__get_cpu_var(saved_next_opcode);
+	struct kprobe *saved = this_cpu_ptr(&saved_next_opcode);
 
 	if (saved->addr) {
 		arch_disarm_kprobe(p);
@@ -111,7 +111,7 @@ void __kprobes arch_remove_kprobe(struct
 		saved->addr = NULL;
 		saved->opcode = 0;
 
-		saved = &__get_cpu_var(saved_next_opcode2);
+		saved = this_cpu_ptr(&saved_next_opcode2);
 		if (saved->addr) {
 			arch_disarm_kprobe(saved);
 
@@ -129,14 +129,14 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }
 
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 					 struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 /*
@@ -146,15 +146,15 @@ static void __kprobes set_current_kprobe
  */
 static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
 {
-	__get_cpu_var(saved_current_opcode).addr = (kprobe_opcode_t *)regs->pc;
+	__this_cpu_write(saved_current_opcode.addr, (kprobe_opcode_t *)regs->pc);
 
 	if (p != NULL) {
 		struct kprobe *op1, *op2;
 
 		arch_disarm_kprobe(p);
 
-		op1 = &__get_cpu_var(saved_next_opcode);
-		op2 = &__get_cpu_var(saved_next_opcode2);
+		op1 = this_cpu_ptr(&saved_next_opcode);
+		op2 = this_cpu_ptr(&saved_next_opcode2);
 
 		if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) {
 			unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
@@ -249,7 +249,7 @@ static int __kprobes kprobe_handler(stru
 			kcb->kprobe_status = KPROBE_REENTER;
 			return 1;
 		} else {
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
@@ -336,9 +336,9 @@ int __kprobes trampoline_probe_handler(s
 			continue;
 
 		if (ri->rp && ri->rp->handler) {
-			__get_cpu_var(current_kprobe) = &ri->rp->kp;
+			__this_cpu_write(current_kprobe, &ri->rp->kp);
 			ri->rp->handler(ri, regs);
-			__get_cpu_var(current_kprobe) = NULL;
+			__this_cpu_write(current_kprobe, NULL);
 		}
 
 		orig_ret_address = (unsigned long)ri->ret_addr;
@@ -383,19 +383,19 @@ static int __kprobes post_kprobe_handler
 		cur->post_handler(cur, regs, 0);
 	}
 
-	p = &__get_cpu_var(saved_next_opcode);
+	p = this_cpu_ptr(&saved_next_opcode);
 	if (p->addr) {
 		arch_disarm_kprobe(p);
 		p->addr = NULL;
 		p->opcode = 0;
 
-		addr = __get_cpu_var(saved_current_opcode).addr;
-		__get_cpu_var(saved_current_opcode).addr = NULL;
+		addr = __this_cpu_read(saved_current_opcode).addr;
+		__this_cpu_write(saved_current_opcode.addr, NULL);
 
 		p = get_kprobe(addr);
 		arch_arm_kprobe(p);
 
-		p = &__get_cpu_var(saved_next_opcode2);
+		p = this_cpu_ptr(&saved_next_opcode2);
 		if (p->addr) {
 			arch_disarm_kprobe(p);
 			p->addr = NULL;
@@ -511,7 +511,7 @@ int __kprobes kprobe_exceptions_notify(s
 				if (kprobe_handler(args->regs)) {
 					ret = NOTIFY_STOP;
 				} else {
-					p = __get_cpu_var(current_kprobe);
+					p = __this_cpu_read(current_kprobe);
 					if (p->break_handler &&
 					    p->break_handler(p, args->regs))
 						ret = NOTIFY_STOP;
Index: linux/arch/sh/kernel/localtimer.c
===================================================================
--- linux.orig/arch/sh/kernel/localtimer.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/localtimer.c	2013-08-26 13:28:32.265604741 -0500
@@ -32,7 +32,7 @@ static DEFINE_PER_CPU(struct clock_event
  */
 void local_timer_interrupt(void)
 {
-	struct clock_event_device *clk = &__get_cpu_var(local_clockevent);
+	struct clock_event_device *clk = this_cpu_ptr(&local_clockevent);
 
 	irq_enter();
 	clk->event_handler(clk);
Index: linux/arch/sh/kernel/perf_event.c
===================================================================
--- linux.orig/arch/sh/kernel/perf_event.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/perf_event.c	2013-08-26 13:28:32.265604741 -0500
@@ -227,7 +227,7 @@ again:
 
 static void sh_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -245,7 +245,7 @@ static void sh_pmu_stop(struct perf_even
 
 static void sh_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -262,7 +262,7 @@ static void sh_pmu_start(struct perf_eve
 
 static void sh_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	sh_pmu_stop(event, PERF_EF_UPDATE);
 	__clear_bit(event->hw.idx, cpuc->used_mask);
@@ -272,7 +272,7 @@ static void sh_pmu_del(struct perf_event
 
 static int sh_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 	int ret = -EAGAIN;
Index: linux/arch/sh/kernel/smp.c
===================================================================
--- linux.orig/arch/sh/kernel/smp.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/smp.c	2013-08-26 13:28:32.265604741 -0500
@@ -111,7 +111,7 @@ void play_dead_common(void)
 	irq_ctx_exit(raw_smp_processor_id());
 	mb();
 
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 	local_irq_disable();
 }
 

[gcv v3 31/35] sh: Replace __get_cpu_var uses

[Christoph Lameter]

__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :


#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))



__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.


This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.




Transformations done to __get_cpu_var()


1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);


2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);


3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);


4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));


5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);


6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)





Index: linux/arch/sh/kernel/hw_breakpoint.c
===================================================================
--- linux.orig/arch/sh/kernel/hw_breakpoint.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/hw_breakpoint.c	2013-08-26 13:28:32.265604741 -0500
@@ -52,7 +52,7 @@ int arch_install_hw_breakpoint(struct pe
 	int i;
 
 	for (i = 0; i < sh_ubc->num_events; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (!*slot) {
 			*slot = bp;
@@ -84,7 +84,7 @@ void arch_uninstall_hw_breakpoint(struct
 	int i;
 
 	for (i = 0; i < sh_ubc->num_events; i++) {
-		struct perf_event **slot = &__get_cpu_var(bp_per_reg[i]);
+		struct perf_event **slot = this_cpu_ptr(&bp_per_reg[i]);
 
 		if (*slot == bp) {
 			*slot = NULL;
Index: linux/arch/sh/kernel/kprobes.c
===================================================================
--- linux.orig/arch/sh/kernel/kprobes.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/kprobes.c	2013-08-26 13:28:32.265604741 -0500
@@ -102,7 +102,7 @@ int __kprobes kprobe_handle_illslot(unsi
 
 void __kprobes arch_remove_kprobe(struct kprobe *p)
 {
-	struct kprobe *saved = &__get_cpu_var(saved_next_opcode);
+	struct kprobe *saved = this_cpu_ptr(&saved_next_opcode);
 
 	if (saved->addr) {
 		arch_disarm_kprobe(p);
@@ -111,7 +111,7 @@ void __kprobes arch_remove_kprobe(struct
 		saved->addr = NULL;
 		saved->opcode = 0;
 
-		saved = &__get_cpu_var(saved_next_opcode2);
+		saved = this_cpu_ptr(&saved_next_opcode2);
 		if (saved->addr) {
 			arch_disarm_kprobe(saved);
 
@@ -129,14 +129,14 @@ static void __kprobes save_previous_kpro
 
 static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
+	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
 	kcb->kprobe_status = kcb->prev_kprobe.status;
 }
 
 static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 					 struct kprobe_ctlblk *kcb)
 {
-	__get_cpu_var(current_kprobe) = p;
+	__this_cpu_write(current_kprobe, p);
 }
 
 /*
@@ -146,15 +146,15 @@ static void __kprobes set_current_kprobe
  */
 static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
 {
-	__get_cpu_var(saved_current_opcode).addr = (kprobe_opcode_t *)regs->pc;
+	__this_cpu_write(saved_current_opcode.addr, (kprobe_opcode_t *)regs->pc);
 
 	if (p != NULL) {
 		struct kprobe *op1, *op2;
 
 		arch_disarm_kprobe(p);
 
-		op1 = &__get_cpu_var(saved_next_opcode);
-		op2 = &__get_cpu_var(saved_next_opcode2);
+		op1 = this_cpu_ptr(&saved_next_opcode);
+		op2 = this_cpu_ptr(&saved_next_opcode2);
 
 		if (OPCODE_JSR(p->opcode) || OPCODE_JMP(p->opcode)) {
 			unsigned int reg_nr = ((p->opcode >> 8) & 0x000F);
@@ -249,7 +249,7 @@ static int __kprobes kprobe_handler(stru
 			kcb->kprobe_status = KPROBE_REENTER;
 			return 1;
 		} else {
-			p = __get_cpu_var(current_kprobe);
+			p = __this_cpu_read(current_kprobe);
 			if (p->break_handler && p->break_handler(p, regs)) {
 				goto ss_probe;
 			}
@@ -336,9 +336,9 @@ int __kprobes trampoline_probe_handler(s
 			continue;
 
 		if (ri->rp && ri->rp->handler) {
-			__get_cpu_var(current_kprobe) = &ri->rp->kp;
+			__this_cpu_write(current_kprobe, &ri->rp->kp);
 			ri->rp->handler(ri, regs);
-			__get_cpu_var(current_kprobe) = NULL;
+			__this_cpu_write(current_kprobe, NULL);
 		}
 
 		orig_ret_address = (unsigned long)ri->ret_addr;
@@ -383,19 +383,19 @@ static int __kprobes post_kprobe_handler
 		cur->post_handler(cur, regs, 0);
 	}
 
-	p = &__get_cpu_var(saved_next_opcode);
+	p = this_cpu_ptr(&saved_next_opcode);
 	if (p->addr) {
 		arch_disarm_kprobe(p);
 		p->addr = NULL;
 		p->opcode = 0;
 
-		addr = __get_cpu_var(saved_current_opcode).addr;
-		__get_cpu_var(saved_current_opcode).addr = NULL;
+		addr = __this_cpu_read(saved_current_opcode).addr;
+		__this_cpu_write(saved_current_opcode.addr, NULL);
 
 		p = get_kprobe(addr);
 		arch_arm_kprobe(p);
 
-		p = &__get_cpu_var(saved_next_opcode2);
+		p = this_cpu_ptr(&saved_next_opcode2);
 		if (p->addr) {
 			arch_disarm_kprobe(p);
 			p->addr = NULL;
@@ -511,7 +511,7 @@ int __kprobes kprobe_exceptions_notify(s
 				if (kprobe_handler(args->regs)) {
 					ret = NOTIFY_STOP;
 				} else {
-					p = __get_cpu_var(current_kprobe);
+					p = __this_cpu_read(current_kprobe);
 					if (p->break_handler &&
 					    p->break_handler(p, args->regs))
 						ret = NOTIFY_STOP;
Index: linux/arch/sh/kernel/localtimer.c
===================================================================
--- linux.orig/arch/sh/kernel/localtimer.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/localtimer.c	2013-08-26 13:28:32.265604741 -0500
@@ -32,7 +32,7 @@ static DEFINE_PER_CPU(struct clock_event
  */
 void local_timer_interrupt(void)
 {
-	struct clock_event_device *clk = &__get_cpu_var(local_clockevent);
+	struct clock_event_device *clk = this_cpu_ptr(&local_clockevent);
 
 	irq_enter();
 	clk->event_handler(clk);
Index: linux/arch/sh/kernel/perf_event.c
===================================================================
--- linux.orig/arch/sh/kernel/perf_event.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/perf_event.c	2013-08-26 13:28:32.265604741 -0500
@@ -227,7 +227,7 @@ again:
 
 static void sh_pmu_stop(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -245,7 +245,7 @@ static void sh_pmu_stop(struct perf_even
 
 static void sh_pmu_start(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
@@ -262,7 +262,7 @@ static void sh_pmu_start(struct perf_eve
 
 static void sh_pmu_del(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
 	sh_pmu_stop(event, PERF_EF_UPDATE);
 	__clear_bit(event->hw.idx, cpuc->used_mask);
@@ -272,7 +272,7 @@ static void sh_pmu_del(struct perf_event
 
 static int sh_pmu_add(struct perf_event *event, int flags)
 {
-	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 	int ret = -EAGAIN;
Index: linux/arch/sh/kernel/smp.c
===================================================================
--- linux.orig/arch/sh/kernel/smp.c	2013-08-26 13:25:18.000000000 -0500
+++ linux/arch/sh/kernel/smp.c	2013-08-26 13:28:32.265604741 -0500
@@ -111,7 +111,7 @@ void play_dead_common(void)
 	irq_ctx_exit(raw_smp_processor_id());
 	mb();
 
-	__get_cpu_var(cpu_state) = CPU_DEAD;
+	__this_cpu_write(cpu_state, CPU_DEAD);
 	local_irq_disable();
 }