Messages in this thread Patch in this message | | | From | Sandipan Das <> | Subject | [PATCH 1/7] x86/cpufeatures: Add PerfMonV2 feature bit | Date | Thu, 17 Mar 2022 11:58:30 +0530 |
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CPUID Fn80000022 i.e. ExtPerfMonAndDbg advertises some new performance monitoring features for upcoming 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> --- 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 65d147974f8d..7af0ee914e2d 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 21d1f062895a..8c0d9b5426f7 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -42,6 +42,7 @@ 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 } }; -- 2.32.0
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