diff mbox series

[v4,03/13] x86/cpufeatures: add X86_FEATURE_WORKLOAD_CLASS feature bit

Message ID 20241021180252.3531-4-mario.limonciello@amd.com
State New
Headers show
Series Add support for AMD hardware feedback interface | expand

Commit Message

Mario Limonciello Oct. 21, 2024, 6:02 p.m. UTC 
From: Perry Yuan <perry.yuan@amd.com>

Add new feature bit that indicates support for workload based
heuristic feedback to OS for scheduling decisions.
When the bit set, threads are classified during runtime into
enumerated classes. The classes represent thread performance/power
characteristics that may benefit from special scheduling behaviors.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 arch/x86/include/asm/cpufeatures.h | 1 +
 arch/x86/kernel/cpu/scattered.c    | 1 +
 2 files changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 7f6c9fc465293..360bbfe8dd44f 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -474,6 +474,7 @@ 
 #define X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT (21*32+ 4) /* Clear branch history at vmexit using SW loop */
 #define X86_FEATURE_AMD_FAST_CPPC		(21*32 + 5) /* Fast CPPC */
 #define X86_FEATURE_AMD_HETEROGENEOUS_CORES	(21*32 + 6) /* Heterogeneous Core Topology */
+#define X86_FEATURE_AMD_WORKLOAD_CLASS	(21*32 + 7) /* Workload Classification */
 
 /*
  * BUG word(s)
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 307a917415343..1e54332594443 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -49,6 +49,7 @@  static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_MBA,		CPUID_EBX,  6, 0x80000008, 0 },
 	{ X86_FEATURE_SMBA,		CPUID_EBX,  2, 0x80000020, 0 },
 	{ X86_FEATURE_BMEC,		CPUID_EBX,  3, 0x80000020, 0 },
+	{ X86_FEATURE_AMD_WORKLOAD_CLASS,	CPUID_EAX,  22, 0x80000021, 0 },
 	{ X86_FEATURE_PERFMON_V2,	CPUID_EAX,  0, 0x80000022, 0 },
 	{ X86_FEATURE_AMD_LBR_V2,	CPUID_EAX,  1, 0x80000022, 0 },
 	{ X86_FEATURE_AMD_LBR_PMC_FREEZE,	CPUID_EAX,  2, 0x80000022, 0 },