linux-kernel - [PATCH v2 3/5] x86/cpufeature: add AMD Accumulated Power Mechanism feature flag

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Message-ID: <1452739808-11871-4-git-send-email-ray.huang@amd.com>
Date:	Thu, 14 Jan 2016 10:50:06 +0800
From:	Huang Rui <ray.huang@....com>
To:	Borislav Petkov <bp@...e.de>,
	Peter Zijlstra <peterz@...radead.org>,
	"Ingo Molnar" <mingo@...nel.org>,
	Andy Lutomirski <luto@...capital.net>,
	"Thomas Gleixner" <tglx@...utronix.de>,
	Robert Richter <rric@...nel.org>,
	Jacob Shin <jacob.w.shin@...il.com>,
	John Stultz <john.stultz@...aro.org>,
	Frédéric Weisbecker <fweisbec@...il.com>
CC:	<linux-kernel@...r.kernel.org>, <spg_linux_kernel@....com>,
	<x86@...nel.org>, Guenter Roeck <linux@...ck-us.net>,
	Andreas Herrmann <herrmann.der.user@...glemail.com>,
	Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
	Aravind Gopalakrishnan <Aravind.Gopalakrishnan@....com>,
	Borislav Petkov <bp@...en8.de>,
	"Fengguang Wu" <fengguang.wu@...el.com>,
	Aaron Lu <aaron.lu@...el.com>, Huang Rui <ray.huang@....com>
Subject: [PATCH v2 3/5] x86/cpufeature: add AMD Accumulated Power Mechanism feature flag

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@....com>
---
 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