From: Sandipan Das <sandipan.das@amd.com>
To: <linux-kernel@vger.kernel.org>,
<linux-perf-users@vger.kernel.org>, <x86@kernel.org>
Cc: <peterz@infradead.org>, <bp@alien8.de>, <acme@kernel.org>,
<namhyung@kernel.org>, <jolsa@kernel.org>, <tglx@linutronix.de>,
<mingo@redhat.com>, <mark.rutland@arm.com>,
<alexander.shishkin@linux.intel.com>,
<dave.hansen@linux.intel.com>, <like.xu.linux@gmail.com>,
<eranian@google.com>, <ananth.narayan@amd.com>,
<ravi.bangoria@amd.com>, <santosh.shukla@amd.com>,
<sandipan.das@amd.com>
Subject: [PATCH 04/13] x86/cpufeatures: Add LbrExtV2 feature bit
Date: Thu, 11 Aug 2022 17:59:52 +0530 [thread overview]
Message-ID: <172d2b0df39306ed77221c45ee1aa62e8ae0548d.1660211399.git.sandipan.das@amd.com> (raw)
In-Reply-To: <cover.1660211399.git.sandipan.das@amd.com>
CPUID leaf 0x80000022 i.e. ExtPerfMonAndDbg advertises some new performance
monitoring features for AMD processors.
Bit 1 of EAX indicates support for Last Branch Record Extension Version 2
(LbrExtV2) features. If found to be set during PMU initialization, the EBX
bits of the same leaf can be used to determine the number of available LBR
entries.
For better utilization of feature words, LbrExtV2 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 393f2bbb5e3a..e3fa476a24b0 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -96,7 +96,7 @@
#define X86_FEATURE_SYSCALL32 ( 3*32+14) /* "" syscall in IA32 userspace */
#define X86_FEATURE_SYSENTER32 ( 3*32+15) /* "" sysenter in IA32 userspace */
#define X86_FEATURE_REP_GOOD ( 3*32+16) /* REP microcode works well */
-/* FREE! ( 3*32+17) */
+#define X86_FEATURE_LBREXT_V2 ( 3*32+17) /* AMD Last Branch Record Extension Version 2 */
#define X86_FEATURE_LFENCE_RDTSC ( 3*32+18) /* "" LFENCE synchronizes RDTSC */
#define X86_FEATURE_ACC_POWER ( 3*32+19) /* AMD Accumulated Power Mechanism */
#define X86_FEATURE_NOPL ( 3*32+20) /* The NOPL (0F 1F) instructions */
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index dbaa8326d6f2..6be46dffddbf 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -44,6 +44,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ 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 },
+ { X86_FEATURE_LBREXT_V2, CPUID_EAX, 1, 0x80000022, 0 },
{ 0, 0, 0, 0, 0 }
};
--
2.34.1
next prev parent reply other threads:[~2022-08-11 12:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-11 12:29 [PATCH 00/13] perf/x86/amd: Add AMD LbrExtV2 support Sandipan Das
2022-08-11 12:29 ` [PATCH 01/13] perf/x86/amd/brs: Move feature-specific functions Sandipan Das
2022-08-11 12:29 ` [PATCH 02/13] perf/x86/amd/core: Refactor branch attributes Sandipan Das
2022-08-11 12:29 ` [PATCH 03/13] perf/x86/amd/core: Add generic branch record interfaces Sandipan Das
2022-08-11 12:29 ` Sandipan Das [this message]
2022-08-11 13:13 ` [PATCH 04/13] x86/cpufeatures: Add LbrExtV2 feature bit Borislav Petkov
2022-08-15 11:27 ` Peter Zijlstra
2022-08-15 19:42 ` Stephane Eranian
2022-08-22 9:05 ` Peter Zijlstra
2022-08-22 12:52 ` Sandipan Das
2022-08-22 13:26 ` Peter Zijlstra
2022-08-23 8:51 ` Sandipan Das
2022-08-25 10:24 ` Peter Zijlstra
2022-08-25 12:26 ` Sandipan Das
2022-08-11 12:29 ` [PATCH 05/13] perf/x86/amd/lbr: Detect LbrExtV2 support Sandipan Das
2022-08-11 12:29 ` [PATCH 06/13] perf/x86/amd/lbr: Add LbrExtV2 branch record support Sandipan Das
2022-08-11 12:29 ` [PATCH 07/13] perf/x86/amd/lbr: Add LbrExtV2 hardware branch filter support Sandipan Das
2022-08-11 12:29 ` [PATCH 08/13] perf/x86: Move branch classifier Sandipan Das
2022-08-11 12:29 ` [PATCH 09/13] perf/x86/amd/lbr: Add LbrExtV2 software branch filter support Sandipan Das
2022-08-11 12:29 ` [PATCH 10/13] perf/x86: Make branch classifier fusion-aware Sandipan Das
2022-08-11 12:29 ` [PATCH 11/13] perf/x86/amd/lbr: Use fusion-aware branch classifier Sandipan Das
2022-08-11 12:30 ` [PATCH 12/13] perf/core: Add speculation info to branch entries Sandipan Das
2022-08-11 12:30 ` [PATCH 13/13] perf/x86/amd/lbr: Add LbrExtV2 branch speculation info support Sandipan Das
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