* [PATCH 0/3] powerpc: fix regression of per-CPU DSCR setting
@ 2014-05-21 6:32 Sam Bobroff
2014-05-21 6:32 ` [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro Sam Bobroff
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Sam Bobroff @ 2014-05-21 6:32 UTC (permalink / raw)
To: benh; +Cc: aik, mikey, linuxppc-dev
Hello,
This patch corrects a regression on PowerPC CPUs that causes their
per-CPU DSCR SPR value (exposed via /sys/devices/system/cpuN/dscr) to
be quickly lost during context switching, effectively meaning that the
DSCR can no longer be set on a per-CPU basis.
My intent is to restore the functionality of the per-CPU value in a
way that is compatible with the newer global default and task-specific
DSCR setting system. Users of either the old or new systems should
now get pretty much what they expect.
A couple of notes:
I've split an existing "ifdef CONFIG_PPC_STD_MMU_64" block in
paca_struct into two parts because it allows dscr_default to be placed
into a cache line hole. (This seems be the case even without
CONFIG_PPC_STD_MMU_64 being defined.) Comments or ideas on alternative
placements are welcome.
PowerPC context switching is touched but there should not be any
performance cost; if anything it should get slightly faster due to the
per-CPU value being easier to access than the old global default.
Sam Bobroff (3):
powerpc: Split __SYSFS_SPRSETUP macro
powerpc: fix regression of per-CPU DSCR setting
powerpc: Document sysfs DSCR interface
Documentation/ABI/stable/sysfs-devices-system-cpu | 25 ++++++++++
arch/powerpc/include/asm/paca.h | 3 ++
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kernel/entry_64.S | 9 +---
arch/powerpc/kernel/sysfs.c | 51 +++++++++++++--------
arch/powerpc/kernel/tm.S | 16 ++-----
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +-
7 files changed, 67 insertions(+), 41 deletions(-)
create mode 100644 Documentation/ABI/stable/sysfs-devices-system-cpu
--
1.7.10.4
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro
2014-05-21 6:32 [PATCH 0/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
@ 2014-05-21 6:32 ` Sam Bobroff
2014-06-02 9:09 ` Madhavan Srinivasan
2014-05-21 6:32 ` [PATCH 2/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
2014-05-21 6:32 ` [PATCH 3/3] powerpc: Document sysfs DSCR interface Sam Bobroff
2 siblings, 1 reply; 6+ messages in thread
From: Sam Bobroff @ 2014-05-21 6:32 UTC (permalink / raw)
To: benh; +Cc: aik, mikey, linuxppc-dev
Split the __SYSFS_SPRSETUP macro into two parts so that registers requiring
custom read and write functions can use common code for their show and store
functions.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
---
arch/powerpc/kernel/sysfs.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index d90d4b7..e2a1d6f 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -404,7 +404,7 @@ void ppc_enable_pmcs(void)
}
EXPORT_SYMBOL(ppc_enable_pmcs);
-#define __SYSFS_SPRSETUP(NAME, ADDRESS, EXTRA) \
+#define __SYSFS_SPRSETUP_READ_WRITE(NAME, ADDRESS, EXTRA) \
static void read_##NAME(void *val) \
{ \
*(unsigned long *)val = mfspr(ADDRESS); \
@@ -413,7 +413,9 @@ static void write_##NAME(void *val) \
{ \
EXTRA; \
mtspr(ADDRESS, *(unsigned long *)val); \
-} \
+}
+
+#define __SYSFS_SPRSETUP_SHOW_STORE(NAME) \
static ssize_t show_##NAME(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
@@ -436,10 +438,15 @@ static ssize_t __used \
return count; \
}
-#define SYSFS_PMCSETUP(NAME, ADDRESS) \
- __SYSFS_SPRSETUP(NAME, ADDRESS, ppc_enable_pmcs())
-#define SYSFS_SPRSETUP(NAME, ADDRESS) \
- __SYSFS_SPRSETUP(NAME, ADDRESS, )
+#define SYSFS_PMCSETUP(NAME, ADDRESS) \
+ __SYSFS_SPRSETUP_READ_WRITE(NAME, ADDRESS, ppc_enable_pmcs()) \
+ __SYSFS_SPRSETUP_SHOW_STORE(NAME)
+#define SYSFS_SPRSETUP(NAME, ADDRESS) \
+ __SYSFS_SPRSETUP_READ_WRITE(NAME, ADDRESS, ) \
+ __SYSFS_SPRSETUP_SHOW_STORE(NAME)
+
+#define SYSFS_SPRSETUP_SHOW_STORE(NAME) \
+ __SYSFS_SPRSETUP_SHOW_STORE(NAME)
/* Let's define all possible registers, we'll only hook up the ones
* that are implemented on the current processor
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/3] powerpc: fix regression of per-CPU DSCR setting
2014-05-21 6:32 [PATCH 0/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
2014-05-21 6:32 ` [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro Sam Bobroff
@ 2014-05-21 6:32 ` Sam Bobroff
2014-06-02 9:27 ` Madhavan Srinivasan
2014-05-21 6:32 ` [PATCH 3/3] powerpc: Document sysfs DSCR interface Sam Bobroff
2 siblings, 1 reply; 6+ messages in thread
From: Sam Bobroff @ 2014-05-21 6:32 UTC (permalink / raw)
To: benh; +Cc: aik, mikey, linuxppc-dev
Since commit "efcac65 powerpc: Per process DSCR + some fixes (try#4)"
it is no longer possible to set the DSCR on a per-CPU basis.
The old behaviour was to minipulate the DSCR SPR directly but this is no
longer sufficient: the value is quickly overwritten by context switching.
This patch stores the per-CPU DSCR value in a kernel variable rather than
directly in the SPR and it is used whenever a process has not set the DSCR
itself. The sysfs interface (/sys/devices/system/cpu/cpuN/dscr) is unchanged.
Writes to the old global default (/sys/devices/system/cpu/dscr_default)
now set all of the per-CPU values and reads return the last written value.
The new per-CPU default is added to the paca_struct and is used everywhere
outside of sysfs.c instead of the old global default.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
---
arch/powerpc/include/asm/paca.h | 3 +++
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kernel/entry_64.S | 9 +--------
arch/powerpc/kernel/sysfs.c | 32 ++++++++++++++++++-------------
arch/powerpc/kernel/tm.S | 16 ++++------------
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +--
6 files changed, 29 insertions(+), 35 deletions(-)
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 8e956a0..bb0bd25 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -92,7 +92,10 @@ struct paca_struct {
struct slb_shadow *slb_shadow_ptr;
struct dtl_entry *dispatch_log;
struct dtl_entry *dispatch_log_end;
+#endif /* CONFIG_PPC_STD_MMU_64 */
+ u64 dscr_default; /* per-CPU default DSCR */
+#ifdef CONFIG_PPC_STD_MMU_64
/*
* Now, starting in cacheline 2, the exception save areas
*/
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index dba8140..cba2697 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -247,6 +247,7 @@ int main(void)
#endif
DEFINE(PACAHWCPUID, offsetof(struct paca_struct, hw_cpu_id));
DEFINE(PACAKEXECSTATE, offsetof(struct paca_struct, kexec_state));
+ DEFINE(PACA_DSCR, offsetof(struct paca_struct, dscr_default));
DEFINE(PACA_STARTTIME, offsetof(struct paca_struct, starttime));
DEFINE(PACA_STARTTIME_USER, offsetof(struct paca_struct, starttime_user));
DEFINE(PACA_USER_TIME, offsetof(struct paca_struct, user_time));
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9fde8a1..911d453 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -387,12 +387,6 @@ _GLOBAL(ret_from_kernel_thread)
li r3,0
b syscall_exit
- .section ".toc","aw"
-DSCR_DEFAULT:
- .tc dscr_default[TC],dscr_default
-
- .section ".text"
-
/*
* This routine switches between two different tasks. The process
* state of one is saved on its kernel stack. Then the state
@@ -577,11 +571,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#ifdef CONFIG_PPC64
BEGIN_FTR_SECTION
lwz r6,THREAD_DSCR_INHERIT(r4)
- ld r7,DSCR_DEFAULT@toc(2)
ld r0,THREAD_DSCR(r4)
cmpwi r6,0
bne 1f
- ld r0,0(r7)
+ ld r0,PACA_DSCR(r13)
1:
BEGIN_FTR_SECTION_NESTED(70)
mfspr r8, SPRN_FSCR
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index e2a1d6f..67fd2fd 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -484,7 +484,6 @@ SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
SYSFS_SPRSETUP(purr, SPRN_PURR);
SYSFS_SPRSETUP(spurr, SPRN_SPURR);
-SYSFS_SPRSETUP(dscr, SPRN_DSCR);
SYSFS_SPRSETUP(pir, SPRN_PIR);
/*
@@ -494,12 +493,27 @@ SYSFS_SPRSETUP(pir, SPRN_PIR);
*/
static DEVICE_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
static DEVICE_ATTR(spurr, 0400, show_spurr, NULL);
-static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
static DEVICE_ATTR(purr, 0400, show_purr, store_purr);
static DEVICE_ATTR(pir, 0400, show_pir, NULL);
-unsigned long dscr_default = 0;
-EXPORT_SYMBOL(dscr_default);
+static unsigned long dscr_default;
+
+static void read_dscr(void *val)
+{
+ *(unsigned long *)val = get_paca()->dscr_default;
+}
+
+static void write_dscr(void *val)
+{
+ get_paca()->dscr_default = *(unsigned long *)val;
+ if (!current->thread.dscr_inherit) {
+ current->thread.dscr = *(unsigned long *)val;
+ mtspr(SPRN_DSCR, *(unsigned long *)val);
+ }
+}
+
+SYSFS_SPRSETUP_SHOW_STORE(dscr);
+static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
static void add_write_permission_dev_attr(struct device_attribute *attr)
{
@@ -512,14 +526,6 @@ static ssize_t show_dscr_default(struct device *dev,
return sprintf(buf, "%lx\n", dscr_default);
}
-static void update_dscr(void *dummy)
-{
- if (!current->thread.dscr_inherit) {
- current->thread.dscr = dscr_default;
- mtspr(SPRN_DSCR, dscr_default);
- }
-}
-
static ssize_t __used store_dscr_default(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
@@ -532,7 +538,7 @@ static ssize_t __used store_dscr_default(struct device *dev,
return -EINVAL;
dscr_default = val;
- on_each_cpu(update_dscr, NULL, 1);
+ on_each_cpu(write_dscr, &val, 1);
return count;
}
diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
index ee061c3..2a324f4 100644
--- a/arch/powerpc/kernel/tm.S
+++ b/arch/powerpc/kernel/tm.S
@@ -78,12 +78,6 @@ _GLOBAL(tm_abort)
TABORT(R3)
blr
- .section ".toc","aw"
-DSCR_DEFAULT:
- .tc dscr_default[TC],dscr_default
-
- .section ".text"
-
/* void tm_reclaim(struct thread_struct *thread,
* unsigned long orig_msr,
* uint8_t cause)
@@ -298,9 +292,8 @@ dont_backup_fp:
mtlr r0
ld r2, STK_GOT(r1)
- /* Load system default DSCR */
- ld r4, DSCR_DEFAULT@toc(r2)
- ld r0, 0(r4)
+ /* Load CPU's default DSCR */
+ ld r0, PACA_DSCR(r13)
mtspr SPRN_DSCR, r0
blr
@@ -479,9 +472,8 @@ restore_gprs:
mtlr r0
ld r2, STK_GOT(r1)
- /* Load system default DSCR */
- ld r4, DSCR_DEFAULT@toc(r2)
- ld r0, 0(r4)
+ /* Load CPU's default DSCR */
+ ld r0, PACA_DSCR(r13)
mtspr SPRN_DSCR, r0
blr
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 9f0ad71..12f4ce5 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -286,8 +286,7 @@ kvm_start_guest:
beq kvm_no_guest
/* Set HSTATE_DSCR(r13) to something sensible */
- LOAD_REG_ADDR(r6, dscr_default)
- ld r6, 0(r6)
+ ld r6, PACA_DSCR(r13)
std r6, HSTATE_DSCR(r13)
bl kvmppc_hv_entry
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 3/3] powerpc: Document sysfs DSCR interface
2014-05-21 6:32 [PATCH 0/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
2014-05-21 6:32 ` [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro Sam Bobroff
2014-05-21 6:32 ` [PATCH 2/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
@ 2014-05-21 6:32 ` Sam Bobroff
2 siblings, 0 replies; 6+ messages in thread
From: Sam Bobroff @ 2014-05-21 6:32 UTC (permalink / raw)
To: benh; +Cc: aik, mikey, linuxppc-dev
Add some documentation about ...
/sys/devices/system/cpu/dscr_default
/sys/devices/system/cpu/cpuN/dscr
... to Documentation/ABI/stable.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
---
Documentation/ABI/stable/sysfs-devices-system-cpu | 25 +++++++++++++++++++++
1 file changed, 25 insertions(+)
create mode 100644 Documentation/ABI/stable/sysfs-devices-system-cpu
diff --git a/Documentation/ABI/stable/sysfs-devices-system-cpu b/Documentation/ABI/stable/sysfs-devices-system-cpu
new file mode 100644
index 0000000..33c133e
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-devices-system-cpu
@@ -0,0 +1,25 @@
+What: /sys/devices/system/cpu/dscr_default
+Date: 13-May-2014
+KernelVersion: v3.15.0
+Contact:
+Description: Writes are equivalent to writing to
+ /sys/devices/system/cpu/cpuN/dscr on all CPUs.
+ Reads return the last written value or 0.
+ This value is not a global default: it is a way to set
+ all per-CPU defaults at the same time.
+Values: 64 bit unsigned integer (bit field)
+
+What: /sys/devices/system/cpu/cpu[0-9]+/dscr
+Date: 13-May-2014
+KernelVersion: v3.15.0
+Contact:
+Description: Default value for the Data Stream Control Register (DSCR) on
+ a CPU.
+ This default value is used when the kernel is executing and
+ for any process that has not set the DSCR itself.
+ If a process ever sets the DSCR (via direct access to the
+ SPR) that value will be persisted for that process and used
+ on any CPU where it executes (overriding the value described
+ here).
+ If set by a process it will be inherited by child processes.
+Values: 64 bit unsigned integer (bit field)
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro
2014-05-21 6:32 ` [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro Sam Bobroff
@ 2014-06-02 9:09 ` Madhavan Srinivasan
0 siblings, 0 replies; 6+ messages in thread
From: Madhavan Srinivasan @ 2014-06-02 9:09 UTC (permalink / raw)
To: linuxppc-dev
On Wednesday 21 May 2014 12:02 PM, Sam Bobroff wrote:
> Split the __SYSFS_SPRSETUP macro into two parts so that registers requiring
> custom read and write functions can use common code for their show and store
> functions.
>
> Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
> ---
> arch/powerpc/kernel/sysfs.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
> index d90d4b7..e2a1d6f 100644
> --- a/arch/powerpc/kernel/sysfs.c
> +++ b/arch/powerpc/kernel/sysfs.c
> @@ -404,7 +404,7 @@ void ppc_enable_pmcs(void)
> }
> EXPORT_SYMBOL(ppc_enable_pmcs);
>
> -#define __SYSFS_SPRSETUP(NAME, ADDRESS, EXTRA) \
> +#define __SYSFS_SPRSETUP_READ_WRITE(NAME, ADDRESS, EXTRA) \
> static void read_##NAME(void *val) \
> { \
> *(unsigned long *)val = mfspr(ADDRESS); \
> @@ -413,7 +413,9 @@ static void write_##NAME(void *val) \
> { \
> EXTRA; \
> mtspr(ADDRESS, *(unsigned long *)val); \
> -} \
> +}
> +
> +#define __SYSFS_SPRSETUP_SHOW_STORE(NAME) \
> static ssize_t show_##NAME(struct device *dev, \
> struct device_attribute *attr, \
> char *buf) \
> @@ -436,10 +438,15 @@ static ssize_t __used \
> return count; \
> }
>
> -#define SYSFS_PMCSETUP(NAME, ADDRESS) \
> - __SYSFS_SPRSETUP(NAME, ADDRESS, ppc_enable_pmcs())
> -#define SYSFS_SPRSETUP(NAME, ADDRESS) \
> - __SYSFS_SPRSETUP(NAME, ADDRESS, )
> +#define SYSFS_PMCSETUP(NAME, ADDRESS) \
> + __SYSFS_SPRSETUP_READ_WRITE(NAME, ADDRESS, ppc_enable_pmcs()) \
> + __SYSFS_SPRSETUP_SHOW_STORE(NAME)
> +#define SYSFS_SPRSETUP(NAME, ADDRESS) \
> + __SYSFS_SPRSETUP_READ_WRITE(NAME, ADDRESS, ) \
> + __SYSFS_SPRSETUP_SHOW_STORE(NAME)
> +
> +#define SYSFS_SPRSETUP_SHOW_STORE(NAME) \
> + __SYSFS_SPRSETUP_SHOW_STORE(NAME)
>
> /* Let's define all possible registers, we'll only hook up the ones
> * that are implemented on the current processor
>
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/3] powerpc: fix regression of per-CPU DSCR setting
2014-05-21 6:32 ` [PATCH 2/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
@ 2014-06-02 9:27 ` Madhavan Srinivasan
0 siblings, 0 replies; 6+ messages in thread
From: Madhavan Srinivasan @ 2014-06-02 9:27 UTC (permalink / raw)
To: linuxppc-dev
On Wednesday 21 May 2014 12:02 PM, Sam Bobroff wrote:
> Since commit "efcac65 powerpc: Per process DSCR + some fixes (try#4)"
> it is no longer possible to set the DSCR on a per-CPU basis.
>
> The old behaviour was to minipulate the DSCR SPR directly but this is no
> longer sufficient: the value is quickly overwritten by context switching.
>
> This patch stores the per-CPU DSCR value in a kernel variable rather than
> directly in the SPR and it is used whenever a process has not set the DSCR
> itself. The sysfs interface (/sys/devices/system/cpu/cpuN/dscr) is unchanged.
>
> Writes to the old global default (/sys/devices/system/cpu/dscr_default)
> now set all of the per-CPU values and reads return the last written value.
>
> The new per-CPU default is added to the paca_struct and is used everywhere
> outside of sysfs.c instead of the old global default.
>
> Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
> ---
> arch/powerpc/include/asm/paca.h | 3 +++
> arch/powerpc/kernel/asm-offsets.c | 1 +
> arch/powerpc/kernel/entry_64.S | 9 +--------
> arch/powerpc/kernel/sysfs.c | 32 ++++++++++++++++++-------------
> arch/powerpc/kernel/tm.S | 16 ++++------------
> arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +--
> 6 files changed, 29 insertions(+), 35 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
> index 8e956a0..bb0bd25 100644
> --- a/arch/powerpc/include/asm/paca.h
> +++ b/arch/powerpc/include/asm/paca.h
> @@ -92,7 +92,10 @@ struct paca_struct {
> struct slb_shadow *slb_shadow_ptr;
> struct dtl_entry *dispatch_log;
> struct dtl_entry *dispatch_log_end;
> +#endif /* CONFIG_PPC_STD_MMU_64 */
> + u64 dscr_default; /* per-CPU default DSCR */
>
> +#ifdef CONFIG_PPC_STD_MMU_64
> /*
> * Now, starting in cacheline 2, the exception save areas
> */
> diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
> index dba8140..cba2697 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -247,6 +247,7 @@ int main(void)
> #endif
> DEFINE(PACAHWCPUID, offsetof(struct paca_struct, hw_cpu_id));
> DEFINE(PACAKEXECSTATE, offsetof(struct paca_struct, kexec_state));
> + DEFINE(PACA_DSCR, offsetof(struct paca_struct, dscr_default));
> DEFINE(PACA_STARTTIME, offsetof(struct paca_struct, starttime));
> DEFINE(PACA_STARTTIME_USER, offsetof(struct paca_struct, starttime_user));
> DEFINE(PACA_USER_TIME, offsetof(struct paca_struct, user_time));
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 9fde8a1..911d453 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -387,12 +387,6 @@ _GLOBAL(ret_from_kernel_thread)
> li r3,0
> b syscall_exit
>
> - .section ".toc","aw"
> -DSCR_DEFAULT:
> - .tc dscr_default[TC],dscr_default
> -
> - .section ".text"
> -
> /*
> * This routine switches between two different tasks. The process
> * state of one is saved on its kernel stack. Then the state
> @@ -577,11 +571,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
> #ifdef CONFIG_PPC64
> BEGIN_FTR_SECTION
> lwz r6,THREAD_DSCR_INHERIT(r4)
> - ld r7,DSCR_DEFAULT@toc(2)
> ld r0,THREAD_DSCR(r4)
> cmpwi r6,0
> bne 1f
> - ld r0,0(r7)
> + ld r0,PACA_DSCR(r13)
> 1:
> BEGIN_FTR_SECTION_NESTED(70)
> mfspr r8, SPRN_FSCR
> diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
> index e2a1d6f..67fd2fd 100644
> --- a/arch/powerpc/kernel/sysfs.c
> +++ b/arch/powerpc/kernel/sysfs.c
> @@ -484,7 +484,6 @@ SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
> SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
> SYSFS_SPRSETUP(purr, SPRN_PURR);
> SYSFS_SPRSETUP(spurr, SPRN_SPURR);
> -SYSFS_SPRSETUP(dscr, SPRN_DSCR);
> SYSFS_SPRSETUP(pir, SPRN_PIR);
>
> /*
> @@ -494,12 +493,27 @@ SYSFS_SPRSETUP(pir, SPRN_PIR);
> */
> static DEVICE_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
> static DEVICE_ATTR(spurr, 0400, show_spurr, NULL);
> -static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
> static DEVICE_ATTR(purr, 0400, show_purr, store_purr);
> static DEVICE_ATTR(pir, 0400, show_pir, NULL);
>
> -unsigned long dscr_default = 0;
> -EXPORT_SYMBOL(dscr_default);
> +static unsigned long dscr_default;
> +
> +static void read_dscr(void *val)
> +{
> + *(unsigned long *)val = get_paca()->dscr_default;
> +}
> +
> +static void write_dscr(void *val)
> +{
> + get_paca()->dscr_default = *(unsigned long *)val;
> + if (!current->thread.dscr_inherit) {
> + current->thread.dscr = *(unsigned long *)val;
> + mtspr(SPRN_DSCR, *(unsigned long *)val);
> + }
> +}
> +
> +SYSFS_SPRSETUP_SHOW_STORE(dscr);
> +static DEVICE_ATTR(dscr, 0600, show_dscr, store_dscr);
>
> static void add_write_permission_dev_attr(struct device_attribute *attr)
> {
> @@ -512,14 +526,6 @@ static ssize_t show_dscr_default(struct device *dev,
> return sprintf(buf, "%lx\n", dscr_default);
> }
>
> -static void update_dscr(void *dummy)
> -{
> - if (!current->thread.dscr_inherit) {
> - current->thread.dscr = dscr_default;
> - mtspr(SPRN_DSCR, dscr_default);
> - }
> -}
> -
> static ssize_t __used store_dscr_default(struct device *dev,
> struct device_attribute *attr, const char *buf,
> size_t count)
> @@ -532,7 +538,7 @@ static ssize_t __used store_dscr_default(struct device *dev,
> return -EINVAL;
> dscr_default = val;
>
> - on_each_cpu(update_dscr, NULL, 1);
> + on_each_cpu(write_dscr, &val, 1);
>
> return count;
> }
Acked-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
> diff --git a/arch/powerpc/kernel/tm.S b/arch/powerpc/kernel/tm.S
> index ee061c3..2a324f4 100644
> --- a/arch/powerpc/kernel/tm.S
> +++ b/arch/powerpc/kernel/tm.S
> @@ -78,12 +78,6 @@ _GLOBAL(tm_abort)
> TABORT(R3)
> blr
>
> - .section ".toc","aw"
> -DSCR_DEFAULT:
> - .tc dscr_default[TC],dscr_default
> -
> - .section ".text"
> -
> /* void tm_reclaim(struct thread_struct *thread,
> * unsigned long orig_msr,
> * uint8_t cause)
> @@ -298,9 +292,8 @@ dont_backup_fp:
> mtlr r0
> ld r2, STK_GOT(r1)
>
> - /* Load system default DSCR */
> - ld r4, DSCR_DEFAULT@toc(r2)
> - ld r0, 0(r4)
> + /* Load CPU's default DSCR */
> + ld r0, PACA_DSCR(r13)
> mtspr SPRN_DSCR, r0
>
> blr
> @@ -479,9 +472,8 @@ restore_gprs:
> mtlr r0
> ld r2, STK_GOT(r1)
>
> - /* Load system default DSCR */
> - ld r4, DSCR_DEFAULT@toc(r2)
> - ld r0, 0(r4)
> + /* Load CPU's default DSCR */
> + ld r0, PACA_DSCR(r13)
> mtspr SPRN_DSCR, r0
>
> blr
> diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> index 9f0ad71..12f4ce5 100644
> --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
> @@ -286,8 +286,7 @@ kvm_start_guest:
> beq kvm_no_guest
>
> /* Set HSTATE_DSCR(r13) to something sensible */
> - LOAD_REG_ADDR(r6, dscr_default)
> - ld r6, 0(r6)
> + ld r6, PACA_DSCR(r13)
> std r6, HSTATE_DSCR(r13)
>
> bl kvmppc_hv_entry
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-06-02 9:27 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-05-21 6:32 [PATCH 0/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
2014-05-21 6:32 ` [PATCH 1/3] powerpc: Split __SYSFS_SPRSETUP macro Sam Bobroff
2014-06-02 9:09 ` Madhavan Srinivasan
2014-05-21 6:32 ` [PATCH 2/3] powerpc: fix regression of per-CPU DSCR setting Sam Bobroff
2014-06-02 9:27 ` Madhavan Srinivasan
2014-05-21 6:32 ` [PATCH 3/3] powerpc: Document sysfs DSCR interface Sam Bobroff
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