[PATCH 3/4] x86/cpufeature: add AMD Accumulated Power Mechanism feature flag

[Huang Rui]

AMD CPU family 15h model 0x60 introduces accumulated power mechanism.
It is used to report the processor power consumption and indicated by
CPUID Fn8000_0007_EDX[12].

Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
---
 arch/x86/include/asm/cpufeature.h | 2 +-
 arch/x86/kernel/cpu/amd.c         | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index f7ba9fb..0adce8f 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -85,7 +85,7 @@
 #define X86_FEATURE_P4		( 3*32+ 7) /* "" P4 */
 #define X86_FEATURE_CONSTANT_TSC ( 3*32+ 8) /* TSC ticks at a constant rate */
 #define X86_FEATURE_UP		( 3*32+ 9) /* smp kernel running on up */
-/* free, was #define X86_FEATURE_FXSAVE_LEAK ( 3*32+10) * "" FXSAVE leaks FOP/FIP/FOP */
+#define X86_FEATURE_ACC_POWER	( 3*32+10) /* AMD Accumulated Power Mechanism */
 #define X86_FEATURE_ARCH_PERFMON ( 3*32+11) /* Intel Architectural PerfMon */
 #define X86_FEATURE_PEBS	( 3*32+12) /* Precise-Event Based Sampling */
 #define X86_FEATURE_BTS		( 3*32+13) /* Branch Trace Store */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index d6e320f..97d4ce2 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -559,6 +559,10 @@ static void early_init_amd(struct cpuinfo_x86 *c)
 			set_sched_clock_stable();
 	}
 
+	/* Bit 12 of 8000_0007 edx is accumulated power mechanism. */
+	if (c->x86_power & BIT(12))
+		set_cpu_cap(c, X86_FEATURE_ACC_POWER);
+
 #ifdef CONFIG_X86_64
 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
 #else
-- 
1.9.1

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