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From: David Woodhouse <dwmw@amazon.co.uk>
To: arjan@linux.intel.com, tglx@linutronix.de, karahmed@amazon.de,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	tim.c.chen@linux.intel.com, bp@alien8.de, peterz@infradead.org,
	pbonzini@redhat.com, ak@linux.intel.com,
	torvalds@linux-foundation.org, gregkh@linux-foundation.org
Subject: [PATCH 2/4] x86/cpufeatures: Add AMD feature bits for Prediction Command
Date: Sat, 20 Jan 2018 12:03:31 +0000	[thread overview]
Message-ID: <1516449813-7654-3-git-send-email-dwmw@amazon.co.uk> (raw)
In-Reply-To: <1516449813-7654-1-git-send-email-dwmw@amazon.co.uk>

AMD doesn't implement the Speculation Control MSR that Intel does, but
the Prediction Control MSR does exist and is advertised by a separate
CPUID bit. Add support for that.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 arch/x86/include/asm/cpufeatures.h | 1 +
 arch/x86/kernel/cpu/scattered.c    | 1 +
 2 files changed, 2 insertions(+)

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index adebdaa..624d978 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -207,6 +207,7 @@
 #define X86_FEATURE_RETPOLINE_AMD	( 7*32+13) /* AMD Retpoline mitigation for Spectre variant 2 */
 #define X86_FEATURE_INTEL_PPIN		( 7*32+14) /* Intel Processor Inventory Number */
 
+#define X86_FEATURE_AMD_PRED_CMD	( 7*32+17) /* Prediction Command MSR (AMD) */
 #define X86_FEATURE_MBA			( 7*32+18) /* Memory Bandwidth Allocation */
 #define X86_FEATURE_RSB_CTXSW		( 7*32+19) /* Fill RSB on context switches */
 
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index df11f5d..c76009e 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -28,6 +28,7 @@ static const struct cpuid_bit cpuid_bits[] = {
 	{ X86_FEATURE_HW_PSTATE,	CPUID_EDX,  7, 0x80000007, 0 },
 	{ X86_FEATURE_CPB,		CPUID_EDX,  9, 0x80000007, 0 },
 	{ X86_FEATURE_PROC_FEEDBACK,    CPUID_EDX, 11, 0x80000007, 0 },
+	{ X86_FEATURE_AMD_PRED_CMD,	CPUID_EDX, 12, 0x80000007, 0 },
 	{ X86_FEATURE_SME,		CPUID_EAX,  0, 0x8000001f, 0 },
 	{ 0, 0, 0, 0, 0 }
 };
-- 
2.7.4

  parent reply	other threads:[~2018-01-20 12:03 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-20 12:03 [PATCH 0/4] Basic Speculation Control feature support David Woodhouse
2018-01-20 12:03 ` [PATCH 1/4] x86/cpufeatures: Add Intel feature bits for Speculation Control David Woodhouse
2018-01-20 20:29   ` Borislav Petkov
2018-01-20 21:51   ` Steven Noonan
2018-01-20 21:57     ` David Woodhouse
2018-01-20 12:03 ` David Woodhouse [this message]
2018-01-21 12:16   ` [PATCH 2/4] x86/cpufeatures: Add AMD feature bits for Prediction Command Borislav Petkov
2018-01-21 12:22     ` David Woodhouse
2018-01-21 12:34       ` Borislav Petkov
2018-01-21 12:41         ` David Woodhouse
2018-01-21 17:36       ` Tom Lendacky
2018-01-21 17:51         ` Borislav Petkov
2018-01-20 12:03 ` [PATCH 3/4] x86/msr: Add definitions for new speculation control MSRs David Woodhouse
2018-01-20 12:03 ` [PATCH 4/4] x86/pti: Do not enable PTI on fixed Intel processors David Woodhouse
2018-01-20 20:08   ` Thomas Gleixner
2018-01-20 20:13     ` Thomas Gleixner
2018-01-20 20:13     ` Woodhouse, David
2018-01-20 20:13     ` Woodhouse, David

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