diff mbox series

[v3] powerpc/kernel/sysfs: Add new config option PMU_SYSFS to enable PMU SPRs sysfs file creation

Message ID 20200106085423.13928-1-kjain@linux.ibm.com (mailing list archive)
State Changes Requested
Headers show
Series [v3] powerpc/kernel/sysfs: Add new config option PMU_SYSFS to enable PMU SPRs sysfs file creation | expand

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Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (9b930eacc2f2331e6ed17e5216075faa3e3dc408)
snowpatch_ozlabs/build-ppc64le success Build succeeded
snowpatch_ozlabs/build-ppc64be success Build succeeded
snowpatch_ozlabs/build-ppc64e success Build succeeded
snowpatch_ozlabs/build-pmac32 success Build succeeded
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Commit Message

Kajol Jain Jan. 6, 2020, 8:54 a.m. UTC 
Many of the performance moniroting unit (PMU) SPRs are
exposed in the sysfs. This may not be a desirable since
"perf" API is the primary interface to program PMU and
collect counter data in the system. But that said, we
cant remove these sysfs files since we dont whether
anyone/anything is using them.

So the patch adds a new CONFIG option 'CONFIG_PMU_SYSFS'
(user selectable) to be used in sysfs file creation for
PMU SPRs. New option by default is disabled, but can be
enabled if user needs it.

Tested this patch behaviour in powernv and pseries machines.
Also did compilation testing for different architecture include:
x86, mips, mips64, alpha, arm. Patch is also compile tested for
pmac32_defconfig.

Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
---
 arch/powerpc/kernel/sysfs.c            | 22 +++++++++++++---------
 arch/powerpc/platforms/Kconfig.cputype |  6 ++++++
 2 files changed, 19 insertions(+), 9 deletions(-)

---
Changelog:
v2 -> v3
- Make 'PMU_SYSFS' config option a user selectable option
  and remove its dependency on 'PERF_EVENTS' option.
- Add PMU_SYSFS config check at time of register/unregister
  PMU SPRs.
- Replace #ifdefs with IS_ENABLE while registering/unregistering
  PMU SPRs.

Resend v2
        Added 'Reviewed-by' and 'Tested-by' tag along with test scenarios.

v1 -> v2
- Added new config option 'PMU_SYSFS' for PMU SPR's creation
  rather than using PERF_EVENTS config option directly and make
  sure SPR's file creation only if 'CONFIG_PERF_EVENTS' disabled.
---

Comments

Michael Ellerman Jan. 7, 2020, 11:10 a.m. UTC | #1 
Kajol Jain <kjain@linux.ibm.com> writes:
> diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
> index 12543e53fa96..58c72b9b8902 100644
> --- a/arch/powerpc/platforms/Kconfig.cputype
> +++ b/arch/powerpc/platforms/Kconfig.cputype
> @@ -417,6 +417,12 @@ config PPC_MM_SLICES
>  config PPC_HAVE_PMU_SUPPORT
>         bool
>  
> +config PMU_SYSFS
> +	bool
> +	default n
> +	help
> +	  This option enables sysfs file creation for PMU SPRs like MMCR* and PMC*.

This isn't user-selectable. It needs a description after `bool` to be
user-selectable.

cheers
Kajol Jain Jan. 8, 2020, 6:10 a.m. UTC | #2 
Hi Michael,

On 1/7/20 4:40 PM, Michael Ellerman wrote:
> Kajol Jain <kjain@linux.ibm.com> writes:
>> diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
>> index 12543e53fa96..58c72b9b8902 100644
>> --- a/arch/powerpc/platforms/Kconfig.cputype
>> +++ b/arch/powerpc/platforms/Kconfig.cputype
>> @@ -417,6 +417,12 @@ config PPC_MM_SLICES
>>   config PPC_HAVE_PMU_SUPPORT
>>          bool
>>   
>> +config PMU_SYSFS
>> +	bool
>> +	default n
>> +	help
>> +	  This option enables sysfs file creation for PMU SPRs like MMCR* and PMC*.
> This isn't user-selectable. It needs a description after `bool` to be
> user-selectable.


Yes you are right. My bad, i was trying by manually enabling/disabling 
PMU_SYSFS. Will update accordingly.

Thanks,

Kajol

> cheers
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 80a676da11cb..d4faa60f1d27 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -606,12 +606,14 @@  static void sysfs_create_dscr_default(void)
 #endif /* CONFIG_PPC64 */
 
 #ifdef HAS_PPC_PMC_PA6T
+#ifdef CONFIG_PMU_SYSFS
 SYSFS_PMCSETUP(pa6t_pmc0, SPRN_PA6T_PMC0);
 SYSFS_PMCSETUP(pa6t_pmc1, SPRN_PA6T_PMC1);
 SYSFS_PMCSETUP(pa6t_pmc2, SPRN_PA6T_PMC2);
 SYSFS_PMCSETUP(pa6t_pmc3, SPRN_PA6T_PMC3);
 SYSFS_PMCSETUP(pa6t_pmc4, SPRN_PA6T_PMC4);
 SYSFS_PMCSETUP(pa6t_pmc5, SPRN_PA6T_PMC5);
+#endif /* CONFIG_PMU_SYSFS */
 #ifdef CONFIG_DEBUG_MISC
 SYSFS_SPRSETUP(hid0, SPRN_HID0);
 SYSFS_SPRSETUP(hid1, SPRN_HID1);
@@ -645,21 +647,21 @@  SYSFS_SPRSETUP(tsr3, SPRN_PA6T_TSR3);
 #endif /* HAS_PPC_PMC_PA6T */
 
 #ifdef HAS_PPC_PMC_IBM
-static struct device_attribute ibm_common_attrs[] = {
+static  __maybe_unused struct device_attribute ibm_common_attrs[] = {
 	__ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
 	__ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
 };
 #endif /* HAS_PPC_PMC_G4 */
 
 #ifdef HAS_PPC_PMC_G4
-static struct device_attribute g4_common_attrs[] = {
+static  __maybe_unused struct device_attribute g4_common_attrs[] = {
 	__ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
 	__ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
 	__ATTR(mmcr2, 0600, show_mmcr2, store_mmcr2),
 };
 #endif /* HAS_PPC_PMC_G4 */
 
-static struct device_attribute classic_pmc_attrs[] = {
+static  __maybe_unused struct device_attribute classic_pmc_attrs[] = {
 	__ATTR(pmc1, 0600, show_pmc1, store_pmc1),
 	__ATTR(pmc2, 0600, show_pmc2, store_pmc2),
 	__ATTR(pmc3, 0600, show_pmc3, store_pmc3),
@@ -674,6 +676,7 @@  static struct device_attribute classic_pmc_attrs[] = {
 
 #ifdef HAS_PPC_PMC_PA6T
 static struct device_attribute pa6t_attrs[] = {
+#ifdef CONFIG_PMU_SYSFS
 	__ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
 	__ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
 	__ATTR(pmc0, 0600, show_pa6t_pmc0, store_pa6t_pmc0),
@@ -682,6 +685,7 @@  static struct device_attribute pa6t_attrs[] = {
 	__ATTR(pmc3, 0600, show_pa6t_pmc3, store_pa6t_pmc3),
 	__ATTR(pmc4, 0600, show_pa6t_pmc4, store_pa6t_pmc4),
 	__ATTR(pmc5, 0600, show_pa6t_pmc5, store_pa6t_pmc5),
+#endif /* CONFIG_PMU_SYSFS */
 #ifdef CONFIG_DEBUG_MISC
 	__ATTR(hid0, 0600, show_hid0, store_hid0),
 	__ATTR(hid1, 0600, show_hid1, store_hid1),
@@ -751,13 +755,12 @@  static int register_cpu_online(unsigned int cpu)
 
 	/* PMC stuff */
 	switch (cur_cpu_spec->pmc_type) {
-#ifdef HAS_PPC_PMC_IBM
+#ifdef CONFIG_PMU_SYSFS
 	case PPC_PMC_IBM:
 		attrs = ibm_common_attrs;
 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct device_attribute);
 		pmc_attrs = classic_pmc_attrs;
 		break;
-#endif /* HAS_PPC_PMC_IBM */
 #ifdef HAS_PPC_PMC_G4
 	case PPC_PMC_G4:
 		attrs = g4_common_attrs;
@@ -765,6 +768,7 @@  static int register_cpu_online(unsigned int cpu)
 		pmc_attrs = classic_pmc_attrs;
 		break;
 #endif /* HAS_PPC_PMC_G4 */
+#endif /* CONFIG_PMU_SYSFS */
 #ifdef HAS_PPC_PMC_PA6T
 	case PPC_PMC_PA6T:
 		/* PA Semi starts counting at PMC0 */
@@ -787,7 +791,7 @@  static int register_cpu_online(unsigned int cpu)
 			device_create_file(s, &pmc_attrs[i]);
 
 #ifdef CONFIG_PPC64
-	if (cpu_has_feature(CPU_FTR_MMCRA))
+	if (IS_ENABLED(CONFIG_PMU_SYSFS) && cpu_has_feature(CPU_FTR_MMCRA))
 		device_create_file(s, &dev_attr_mmcra);
 
 	if (cpu_has_feature(CPU_FTR_PURR)) {
@@ -840,13 +844,12 @@  static int unregister_cpu_online(unsigned int cpu)
 
 	/* PMC stuff */
 	switch (cur_cpu_spec->pmc_type) {
-#ifdef HAS_PPC_PMC_IBM
+#ifdef CONFIG_PMU_SYSFS
 	case PPC_PMC_IBM:
 		attrs = ibm_common_attrs;
 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct device_attribute);
 		pmc_attrs = classic_pmc_attrs;
 		break;
-#endif /* HAS_PPC_PMC_IBM */
 #ifdef HAS_PPC_PMC_G4
 	case PPC_PMC_G4:
 		attrs = g4_common_attrs;
@@ -854,6 +857,7 @@  static int unregister_cpu_online(unsigned int cpu)
 		pmc_attrs = classic_pmc_attrs;
 		break;
 #endif /* HAS_PPC_PMC_G4 */
+#endif /* CONFIG_PMU_SYSFS */
 #ifdef HAS_PPC_PMC_PA6T
 	case PPC_PMC_PA6T:
 		/* PA Semi starts counting at PMC0 */
@@ -876,7 +880,7 @@  static int unregister_cpu_online(unsigned int cpu)
 			device_remove_file(s, &pmc_attrs[i]);
 
 #ifdef CONFIG_PPC64
-	if (cpu_has_feature(CPU_FTR_MMCRA))
+	if (IS_ENABLED(CONFIG_PMU_SYSFS) && cpu_has_feature(CPU_FTR_MMCRA))
 		device_remove_file(s, &dev_attr_mmcra);
 
 	if (cpu_has_feature(CPU_FTR_PURR))
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 12543e53fa96..58c72b9b8902 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -417,6 +417,12 @@  config PPC_MM_SLICES
 config PPC_HAVE_PMU_SUPPORT
        bool
 
+config PMU_SYSFS
+	bool
+	default n
+	help
+	  This option enables sysfs file creation for PMU SPRs like MMCR* and PMC*.
+
 config PPC_PERF_CTRS
        def_bool y
        depends on PERF_EVENTS && PPC_HAVE_PMU_SUPPORT