From 22697da36d0cee57c2a5750ef7d84e4d88da17e7 Mon Sep 17 00:00:00 2001
From: Kajol Jain <kjain@linux.ibm.com>
Date: Fri, 14 Feb 2020 13:36:06 +0530
Subject: [PATCH] powerpc/kernel/sysfs: Add new config option PMU_SYSFS to
enable PMU SPRs sysfs file creation
References: jsc#SLE-13513
Patch-mainline: v5.7-rc1
Git-commit: 22697da36d0cee57c2a5750ef7d84e4d88da17e7
Many of the performance monitoring 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.
Patch is also tested for pmac32_defconfig.
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@in.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200214080606.26872-2-kjain@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/sysfs.c | 6 ++++++
arch/powerpc/platforms/Kconfig.cputype | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 74da5ebf088e..479c70680b76 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -562,6 +562,7 @@ EXPORT_SYMBOL(ppc_enable_pmcs);
* that are implemented on the current processor
*/
+#ifdef CONFIG_PMU_SYSFS
#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_BOOK3S_32)
#define HAS_PPC_PMC_CLASSIC 1
#define HAS_PPC_PMC_IBM 1
@@ -575,6 +576,7 @@ EXPORT_SYMBOL(ppc_enable_pmcs);
#ifdef CONFIG_PPC_BOOK3S_32
#define HAS_PPC_PMC_G4 1
#endif
+#endif /* CONFIG_PMU_SYSFS */
#if defined(CONFIG_PPC64) && defined(CONFIG_DEBUG_MISC)
#define HAS_PPC_PA6T
@@ -812,8 +814,10 @@ static int register_cpu_online(unsigned int cpu)
device_create_file(s, &pmc_attrs[i]);
#ifdef CONFIG_PPC64
+#ifdef CONFIG_PMU_SYSFS
if (cpu_has_feature(CPU_FTR_MMCRA))
device_create_file(s, &dev_attr_mmcra);
+#endif /* CONFIG_PMU_SYSFS */
if (cpu_has_feature(CPU_FTR_PURR)) {
if (!firmware_has_feature(FW_FEATURE_LPAR))
@@ -901,8 +905,10 @@ static int unregister_cpu_online(unsigned int cpu)
device_remove_file(s, &pmc_attrs[i]);
#ifdef CONFIG_PPC64
+#ifdef CONFIG_PMU_SYSFS
if (cpu_has_feature(CPU_FTR_MMCRA))
device_remove_file(s, &dev_attr_mmcra);
+#endif /* CONFIG_PMU_SYSFS */
if (cpu_has_feature(CPU_FTR_PURR))
device_remove_file(s, &dev_attr_purr);
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 6caedc88474f..4208724e9f28 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -425,6 +425,12 @@ config PPC_MM_SLICES
config PPC_HAVE_PMU_SUPPORT
bool
+config PMU_SYSFS
+ bool "Create PMU SPRs sysfs file"
+ 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
--
2.28.0