[tip: perf/core] x86/cpufeatures: Add PerfMonV2 feature bit

[tip: perf/core] x86/cpufeatures: Add PerfMonV2 feature bit

[tip-bot2 for Sandipan Das]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     2ae6fea3facb4d704d449e562a4971b1a7465fde
Gitweb:        https://git.kernel.org/tip/2ae6fea3facb4d704d449e562a4971b1a7465fde
Author:        Sandipan Das <sandipan.das@amd.com>
AuthorDate:    Thu, 21 Apr 2022 11:16:53 +05:30
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 29 Apr 2022 11:06:26 +02:00

x86/cpufeatures: Add PerfMonV2 feature bit

CPUID leaf 0x80000022 i.e. ExtPerfMonAndDbg advertises some
new performance monitoring features for AMD processors.

Bit 0 of EAX indicates support for Performance Monitoring
Version 2 (PerfMonV2) features. If found to be set during
PMU initialization, the EBX bits of the same CPUID function
can be used to determine the number of available PMCs for
different PMU types. Additionally, Core PMCs can be managed
using new global control and status registers.

For better utilization of feature words, PerfMonV2 is added
as a scattered feature bit.

Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/c70e497e22f18e7f05b025bb64ca21cc12b17792.1650515382.git.sandipan.das@amd.com
---
 arch/x86/include/asm/cpufeatures.h | 2 +-
 arch/x86/kernel/cpu/scattered.c    | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 0d62afd..1ded261 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -201,7 +201,7 @@
 #define X86_FEATURE_INVPCID_SINGLE	( 7*32+ 7) /* Effectively INVPCID && CR4.PCIDE=1 */
 #define X86_FEATURE_HW_PSTATE		( 7*32+ 8) /* AMD HW-PState */
 #define X86_FEATURE_PROC_FEEDBACK	( 7*32+ 9) /* AMD ProcFeedbackInterface */
-/* FREE!                                ( 7*32+10) */
+#define X86_FEATURE_PERFMON_V2		( 7*32+10) /* AMD Performance Monitoring Version 2 */
 #define X86_FEATURE_PTI			( 7*32+11) /* Kernel Page Table Isolation enabled */
 #define X86_FEATURE_RETPOLINE		( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
 #define X86_FEATURE_RETPOLINE_LFENCE	( 7*32+13) /* "" Use LFENCE for Spectre variant 2 */
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 4143b1e..dbaa832 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -43,6 +43,7 @@ static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_CPB,		CPUID_EDX,  9, 0x80000007, 0 },
 	{ X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },
 	{ X86_FEATURE_MBA,		CPUID_EBX,  6, 0x80000008, 0 },
+	{ X86_FEATURE_PERFMON_V2,	CPUID_EAX,  0, 0x80000022, 0 },
 	{ 0, 0, 0, 0, 0 }
 };
 

[tip: perf/core] x86/cpufeatures: Add PerfMonV2 feature bit

[tip-bot2 for Sandipan Das]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     d6d0c7f681fda1d07e005c8f653e578b77a0eb40
Gitweb:        https://git.kernel.org/tip/d6d0c7f681fda1d07e005c8f653e578b77a0eb40
Author:        Sandipan Das <sandipan.das@amd.com>
AuthorDate:    Thu, 21 Apr 2022 11:16:53 +05:30
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 04 May 2022 11:17:15 +02:00

x86/cpufeatures: Add PerfMonV2 feature bit

CPUID leaf 0x80000022 i.e. ExtPerfMonAndDbg advertises some
new performance monitoring features for AMD processors.

Bit 0 of EAX indicates support for Performance Monitoring
Version 2 (PerfMonV2) features. If found to be set during
PMU initialization, the EBX bits of the same CPUID function
can be used to determine the number of available PMCs for
different PMU types. Additionally, Core PMCs can be managed
using new global control and status registers.

For better utilization of feature words, PerfMonV2 is added
as a scattered feature bit.

Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/c70e497e22f18e7f05b025bb64ca21cc12b17792.1650515382.git.sandipan.das@amd.com
---
 arch/x86/include/asm/cpufeatures.h | 2 +-
 arch/x86/kernel/cpu/scattered.c    | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 0d62afd..b50e087 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -211,7 +211,7 @@
 #define X86_FEATURE_SSBD		( 7*32+17) /* Speculative Store Bypass Disable */
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
 #define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* "" Fill RSB on context switches */
-/* FREE!                                ( 7*32+20) */
+#define X86_FEATURE_PERFMON_V2		( 7*32+20) /* AMD Performance Monitoring Version 2 */
 #define X86_FEATURE_USE_IBPB		( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */
 #define X86_FEATURE_USE_IBRS_FW		( 7*32+22) /* "" Use IBRS during runtime firmware calls */
 #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE	( 7*32+23) /* "" Disable Speculative Store Bypass. */
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 4143b1e..dbaa832 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -43,6 +43,7 @@ static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_CPB,		CPUID_EDX,  9, 0x80000007, 0 },
 	{ X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },
 	{ X86_FEATURE_MBA,		CPUID_EBX,  6, 0x80000008, 0 },
+	{ X86_FEATURE_PERFMON_V2,	CPUID_EAX,  0, 0x80000022, 0 },
 	{ 0, 0, 0, 0, 0 }
 };