Re: [PATCH] i386: init early_gdt_descr and idle task properly on voyager

[Jeremy Fitzhardinge <jeremy@goop.org>]

[-- Attachment #1: Type: text/plain, Size: 472 bytes --]

James Bottomley wrote:
> On Sat, 2007-04-28 at 17:21 -0700, Jeremy Fitzhardinge wrote:
>   
>> Initialize early_gdt_descr and idle task properly.
>>
>> [ Incremental fix for "i386: introduce voyager smp_ops, fix voyager build" ]
>>     
>
> Still not quite enough.  this is what I need to complete the build:
>   

Yep.  I fixed this up in a later pair of patches:
"i386-common-smp.patch" and
"i386-fix-voyager-build.patch".

Does it work for you when you do this?

    J

[-- Attachment #2: i386-common-smp.patch --]
[-- Type: text/x-patch, Size: 8789 bytes --]

Subject: i386: move common parts of smp into their own file

Several parts of kernel/smp.c and smpboot.c are generally useful for
other subarchitectures and paravirt_ops implementations, so make them
available for reuse.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>

---
 arch/i386/kernel/Makefile    |    1 
 arch/i386/kernel/smp.c       |   65 +++-------------------------------
 arch/i386/kernel/smpboot.c   |   22 -----------
 arch/i386/kernel/smpcommon.c |   79 ++++++++++++++++++++++++++++++++++++++++++
 include/asm-i386/processor.h |    4 ++
 5 files changed, 90 insertions(+), 81 deletions(-)

===================================================================
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_MICROCODE)		+= microcode.o
 obj-$(CONFIG_MICROCODE)		+= microcode.o
 obj-$(CONFIG_APM)		+= apm.o
 obj-$(CONFIG_X86_SMP)		+= smp.o smpboot.o tsc_sync.o
+obj-$(CONFIG_SMP)		+= smpcommon.o
 obj-$(CONFIG_X86_TRAMPOLINE)	+= trampoline.o
 obj-$(CONFIG_X86_MPPARSE)	+= mpparse.o
 obj-$(CONFIG_X86_LOCAL_APIC)	+= apic.o nmi.o
===================================================================
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -468,7 +468,7 @@ void flush_tlb_all(void)
  * it goes straight through and wastes no time serializing
  * anything. Worst case is that we lose a reschedule ...
  */
-void native_smp_send_reschedule(int cpu)
+static void native_smp_send_reschedule(int cpu)
 {
 	WARN_ON(cpu_is_offline(cpu));
 	send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR);
@@ -547,9 +547,10 @@ static void __smp_call_function(void (*f
  * You must not call this function with disabled interrupts or from a
  * hardware interrupt handler or from a bottom half handler.
  */
-int native_smp_call_function_mask(cpumask_t mask,
-				  void (*func)(void *), void *info,
-				  int wait)
+static int
+native_smp_call_function_mask(cpumask_t mask,
+			      void (*func)(void *), void *info,
+			      int wait)
 {
 	struct call_data_struct data;
 	cpumask_t allbutself;
@@ -600,60 +601,6 @@ int native_smp_call_function_mask(cpumas
 	return 0;
 }
 
-/**
- * smp_call_function(): Run a function on all other CPUs.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: Unused.
- * @wait: If true, wait (atomically) until function has completed on other CPUs.
- *
- * Returns 0 on success, else a negative status code.
- *
- * If @wait is true, then returns once @func has returned; otherwise
- * it returns just before the target cpu calls @func.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- */
-int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
-		      int wait)
-{
-	return smp_call_function_mask(cpu_online_map, func, info, wait);
-}
-EXPORT_SYMBOL(smp_call_function);
-
-/**
- * smp_call_function_single - Run a function on another CPU
- * @cpu: The target CPU.  Cannot be the calling CPU.
- * @func: The function to run. This must be fast and non-blocking.
- * @info: An arbitrary pointer to pass to the function.
- * @nonatomic: Unused.
- * @wait: If true, wait until function has completed on other CPUs.
- *
- * Returns 0 on success, else a negative status code.
- *
- * If @wait is true, then returns once @func has returned; otherwise
- * it returns just before the target cpu calls @func.
- */
-int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
-			     int nonatomic, int wait)
-{
-	/* prevent preemption and reschedule on another processor */
-	int ret;
-	int me = get_cpu();
-	if (cpu == me) {
-		WARN_ON(1);
-		put_cpu();
-		return -EBUSY;
-	}
-
-	ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
-
-	put_cpu();
-	return ret;
-}
-EXPORT_SYMBOL(smp_call_function_single);
-
 static void stop_this_cpu (void * dummy)
 {
 	local_irq_disable();
@@ -671,7 +618,7 @@ static void stop_this_cpu (void * dummy)
  * this function calls the 'stop' function on all other CPUs in the system.
  */
 
-void native_smp_send_stop(void)
+static void native_smp_send_stop(void)
 {
 	/* Don't deadlock on the call lock in panic */
 	int nolock = !spin_trylock(&call_lock);
===================================================================
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -99,9 +99,6 @@ EXPORT_SYMBOL(x86_cpu_to_apicid);
 
 u8 apicid_2_node[MAX_APICID];
 
-DEFINE_PER_CPU(unsigned long, this_cpu_off);
-EXPORT_PER_CPU_SYMBOL(this_cpu_off);
-
 /*
  * Trampoline 80x86 program as an array.
  */
@@ -766,25 +763,6 @@ static inline struct task_struct * alloc
 #define alloc_idle_task(cpu) fork_idle(cpu)
 #endif
 
-/* Initialize the CPU's GDT.  This is either the boot CPU doing itself
-   (still using the master per-cpu area), or a CPU doing it for a
-   secondary which will soon come up. */
-static __cpuinit void init_gdt(int cpu)
-{
-	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
-
-	pack_descriptor((u32 *)&gdt[GDT_ENTRY_PERCPU].a,
-			(u32 *)&gdt[GDT_ENTRY_PERCPU].b,
-			__per_cpu_offset[cpu], 0xFFFFF,
-			0x80 | DESCTYPE_S | 0x2, 0x8);
-
-	per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
-	per_cpu(cpu_number, cpu) = cpu;
-}
-
-/* Defined in head.S */
-extern struct Xgt_desc_struct early_gdt_descr;
-
 static int __cpuinit do_boot_cpu(int apicid, int cpu)
 /*
  * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
===================================================================
--- /dev/null
+++ b/arch/i386/kernel/smpcommon.c
@@ -0,0 +1,79 @@
+/*
+ * SMP stuff which is common to all sub-architectures.
+ */
+#include <linux/module.h>
+#include <asm/smp.h>
+
+DEFINE_PER_CPU(unsigned long, this_cpu_off);
+EXPORT_PER_CPU_SYMBOL(this_cpu_off);
+
+/* Initialize the CPU's GDT.  This is either the boot CPU doing itself
+   (still using the master per-cpu area), or a CPU doing it for a
+   secondary which will soon come up. */
+__cpuinit void init_gdt(int cpu)
+{
+	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
+
+	pack_descriptor((u32 *)&gdt[GDT_ENTRY_PERCPU].a,
+			(u32 *)&gdt[GDT_ENTRY_PERCPU].b,
+			__per_cpu_offset[cpu], 0xFFFFF,
+			0x80 | DESCTYPE_S | 0x2, 0x8);
+
+	per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
+	per_cpu(cpu_number, cpu) = cpu;
+}
+
+
+/**
+ * smp_call_function(): Run a function on all other CPUs.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @nonatomic: Unused.
+ * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ *
+ * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
+		      int wait)
+{
+	return smp_call_function_mask(cpu_online_map, func, info, wait);
+}
+EXPORT_SYMBOL(smp_call_function);
+
+/**
+ * smp_call_function_single - Run a function on another CPU
+ * @cpu: The target CPU.  Cannot be the calling CPU.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @nonatomic: Unused.
+ * @wait: If true, wait until function has completed on other CPUs.
+ *
+ * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ */
+int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+			     int nonatomic, int wait)
+{
+	/* prevent preemption and reschedule on another processor */
+	int ret;
+	int me = get_cpu();
+	if (cpu == me) {
+		WARN_ON(1);
+		put_cpu();
+		return -EBUSY;
+	}
+
+	ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
+
+	put_cpu();
+	return ret;
+}
+EXPORT_SYMBOL(smp_call_function_single);
===================================================================
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -749,9 +749,13 @@ extern void enable_sep_cpu(void);
 extern void enable_sep_cpu(void);
 extern int sysenter_setup(void);
 
+/* Defined in head.S */
+extern struct Xgt_desc_struct early_gdt_descr;
+
 extern void cpu_set_gdt(int);
 extern void switch_to_new_gdt(void);
 extern void cpu_init(void);
+extern void init_gdt(int cpu);
 
 extern int force_mwait;
 

[-- Attachment #3: i386-fix-voyager-build.patch --]
[-- Type: text/x-patch, Size: 5957 bytes --]

Subject: i386: fix voyager build

This adds an smp_ops for voyager, and hooks things up appropriately.
This is the first baby-step to making subarch runtime switchable.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>

---
 arch/i386/mach-voyager/voyager_smp.c |   73 ++++++++++++++++++++--------------
 1 file changed, 44 insertions(+), 29 deletions(-)

===================================================================
--- a/arch/i386/mach-voyager/voyager_smp.c
+++ b/arch/i386/mach-voyager/voyager_smp.c
@@ -28,7 +28,6 @@
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 #include <asm/arch_hooks.h>
-#include <asm/pda.h>
 
 /* TLB state -- visible externally, indexed physically */
 DEFINE_PER_CPU(struct tlb_state, cpu_tlbstate) ____cacheline_aligned = { &init_mm, 0 };
@@ -423,7 +422,7 @@ find_smp_config(void)
 	     VOYAGER_SUS_IN_CONTROL_PORT);
 
 	current_thread_info()->cpu = boot_cpu_id;
-	write_pda(cpu_number, boot_cpu_id);
+	x86_write_percpu(cpu_number, boot_cpu_id);
 }
 
 /*
@@ -436,7 +435,7 @@ smp_store_cpu_info(int id)
 
 	*c = boot_cpu_data;
 
-	identify_cpu(c);
+	identify_secondary_cpu(c);
 }
 
 /* set up the trampoline and return the physical address of the code */
@@ -460,7 +459,7 @@ start_secondary(void *unused)
 	/* external functions not defined in the headers */
 	extern void calibrate_delay(void);
 
-	secondary_cpu_init();
+	cpu_init();
 
 	/* OK, we're in the routine */
 	ack_CPI(VIC_CPU_BOOT_CPI);
@@ -580,7 +579,9 @@ do_boot_cpu(__u8 cpu)
 	/* init_tasks (in sched.c) is indexed logically */
 	stack_start.esp = (void *) idle->thread.esp;
 
-	init_gdt(cpu, idle);
+	init_gdt(cpu);
+ 	per_cpu(current_task, cpu) = idle;
+	early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
 	irq_ctx_init(cpu);
 
 	/* Note: Don't modify initial ss override */
@@ -884,8 +885,8 @@ smp_invalidate_interrupt(void)
 
 /* This routine is called with a physical cpu mask */
 static void
-flush_tlb_others (unsigned long cpumask, struct mm_struct *mm,
-						unsigned long va)
+voyager_flush_tlb_others (unsigned long cpumask, struct mm_struct *mm,
+			  unsigned long va)
 {
 	int stuck = 50000;
 
@@ -937,7 +938,7 @@ flush_tlb_current_task(void)
 	cpu_mask = cpus_addr(mm->cpu_vm_mask)[0] & ~(1 << smp_processor_id());
 	local_flush_tlb();
 	if (cpu_mask)
-		flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+		voyager_flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
 
 	preempt_enable();
 }
@@ -959,7 +960,7 @@ flush_tlb_mm (struct mm_struct * mm)
 			leave_mm(smp_processor_id());
 	}
 	if (cpu_mask)
-		flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+		voyager_flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
 
 	preempt_enable();
 }
@@ -980,7 +981,7 @@ void flush_tlb_page(struct vm_area_struc
 	}
 
 	if (cpu_mask)
-		flush_tlb_others(cpu_mask, mm, va);
+		voyager_flush_tlb_others(cpu_mask, mm, va);
 
 	preempt_enable();
 }
@@ -1076,12 +1077,13 @@ smp_call_function_interrupt(void)
     [RETURNS] 0 on success, else a negative status code. Does not return until
     remote CPUs are nearly ready to execute <<func>> or are or have executed.
 */
-int
-smp_call_function (void (*func) (void *info), void *info, int retry,
-		   int wait)
+static int
+voyager_smp_call_function_mask (cpumask_t cpumask,
+				void (*func) (void *info), void *info,
+				int wait)
 {
 	struct call_data_struct data;
-	__u32 mask = cpus_addr(cpu_online_map)[0];
+	u32 mask = cpumask.bits[0];
 
 	mask &= ~(1<<smp_processor_id());
 
@@ -1116,7 +1118,6 @@ smp_call_function (void (*func) (void *i
 
 	return 0;
 }
-EXPORT_SYMBOL(smp_call_function);
 
 /* Sorry about the name.  In an APIC based system, the APICs
  * themselves are programmed to send a timer interrupt.  This is used
@@ -1231,8 +1232,8 @@ smp_alloc_memory(void)
 }
 
 /* send a reschedule CPI to one CPU by physical CPU number*/
-void
-smp_send_reschedule(int cpu)
+static void
+voyager_smp_send_reschedule(int cpu)
 {
 	send_one_CPI(cpu, VIC_RESCHEDULE_CPI);
 }
@@ -1261,8 +1262,8 @@ safe_smp_processor_id(void)
 }
 
 /* broadcast a halt to all other CPUs */
-void
-smp_send_stop(void)
+static void
+voyager_smp_send_stop(void)
 {
 	smp_call_function(smp_stop_cpu_function, NULL, 1, 1);
 }
@@ -1924,23 +1925,26 @@ smp_voyager_power_off(void *dummy)
 		smp_stop_cpu_function(NULL);
 }
 
-void __init
-smp_prepare_cpus(unsigned int max_cpus)
+static void __init
+voyager_smp_prepare_cpus(unsigned int max_cpus)
 {
 	/* FIXME: ignore max_cpus for now */
 	smp_boot_cpus();
 }
 
-void __devinit smp_prepare_boot_cpu(void)
-{
+static void __devinit voyager_smp_prepare_boot_cpu(void)
+{
+	init_gdt(smp_processor_id());
+	switch_to_new_gdt();
+
 	cpu_set(smp_processor_id(), cpu_online_map);
 	cpu_set(smp_processor_id(), cpu_callout_map);
 	cpu_set(smp_processor_id(), cpu_possible_map);
 	cpu_set(smp_processor_id(), cpu_present_map);
 }
 
-int __devinit
-__cpu_up(unsigned int cpu)
+static int __devinit
+voyager_cpu_up(unsigned int cpu)
 {
 	/* This only works at boot for x86.  See "rewrite" above. */
 	if (cpu_isset(cpu, smp_commenced_mask))
@@ -1956,8 +1960,8 @@ __cpu_up(unsigned int cpu)
 	return 0;
 }
 
-void __init 
-smp_cpus_done(unsigned int max_cpus)
+static void __init
+voyager_smp_cpus_done(unsigned int max_cpus)
 {
 	zap_low_mappings();
 }
@@ -1966,5 +1970,16 @@ smp_setup_processor_id(void)
 smp_setup_processor_id(void)
 {
 	current_thread_info()->cpu = hard_smp_processor_id();
-	write_pda(cpu_number, hard_smp_processor_id());
-}
+	x86_write_percpu(cpu_number, hard_smp_processor_id());
+}
+
+struct smp_ops smp_ops = {
+	.smp_prepare_boot_cpu = voyager_smp_prepare_boot_cpu,
+	.smp_prepare_cpus = voyager_smp_prepare_cpus,
+	.cpu_up = voyager_cpu_up,
+	.smp_cpus_done = voyager_smp_cpus_done,
+
+	.smp_send_stop = voyager_smp_send_stop,
+	.smp_send_reschedule = voyager_smp_send_reschedule,
+	.smp_call_function_mask = voyager_smp_call_function_mask,
+};