Messages in this thread Patch in this message | | | From | kan.liang@linux ... | Subject | [PATCH V3 01/23] x86/cpufeatures: Add Architectural LBRs feature bit | Date | Fri, 3 Jul 2020 05:49:07 -0700 |
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From: Kan Liang <kan.liang@linux.intel.com>
CPUID.(EAX=07H, ECX=0):EDX[19] indicates whether an Intel CPU supports Architectural LBRs.
The "X86_FEATURE_..., word 18" is already mirrored from CPUID "0x00000007:0 (EDX)". Add X86_FEATURE_ARCH_LBR under the "word 18" section.
The feature will appear as "arch_lbr" in /proc/cpuinfo.
The Architectural Last Branch Records (LBR) feature enables recording of software path history by logging taken branches and other control flows. The feature will be supported in the perf_events subsystem.
Reviewed-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> --- arch/x86/include/asm/cpufeatures.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 02dabc9..72ba4c5 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -366,6 +366,7 @@ #define X86_FEATURE_MD_CLEAR (18*32+10) /* VERW clears CPU buffers */ #define X86_FEATURE_TSX_FORCE_ABORT (18*32+13) /* "" TSX_FORCE_ABORT */ #define X86_FEATURE_PCONFIG (18*32+18) /* Intel PCONFIG */ +#define X86_FEATURE_ARCH_LBR (18*32+19) /* Intel ARCH LBR */ #define X86_FEATURE_SPEC_CTRL (18*32+26) /* "" Speculation Control (IBRS + IBPB) */ #define X86_FEATURE_INTEL_STIBP (18*32+27) /* "" Single Thread Indirect Branch Predictors */ #define X86_FEATURE_FLUSH_L1D (18*32+28) /* Flush L1D cache */ -- 2.7.4
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