Commit-ID: ace6485a03266cc3c198ce8e927a1ce0ce139699 Gitweb: https://git.kernel.org/tip/ace6485a03266cc3c198ce8e927a1ce0ce139699 Author: Fenghua Yu <[email protected]> AuthorDate: Wed, 24 Oct 2018 14:57:17 -0700 Committer: Ingo Molnar <[email protected]> CommitDate: Thu, 25 Oct 2018 07:42:48 +0200
x86/cpufeatures: Enumerate MOVDIR64B instruction MOVDIR64B moves 64-bytes as direct-store with 64-bytes write atomicity. Direct store is implemented by using write combining (WC) for writing data directly into memory without caching the data. In low latency offload (e.g. Non-Volatile Memory, etc), MOVDIR64B writes work descriptors (and data in some cases) to device-hosted work-queues atomically without cache pollution. Availability of the MOVDIR64B instruction is indicated by the presence of the CPUID feature flag MOVDIR64B (CPUID.0x07.0x0:ECX[bit 28]). Please check the latest Intel Architecture Instruction Set Extensions and Future Features Programming Reference for more details on the CPUID feature MOVDIR64B flag. Signed-off-by: Fenghua Yu <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ashok Raj <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi V Shankar <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/include/asm/cpufeatures.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 90934ee7b79a..28c4a502b419 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -332,6 +332,7 @@ #define X86_FEATURE_RDPID (16*32+22) /* RDPID instruction */ #define X86_FEATURE_CLDEMOTE (16*32+25) /* CLDEMOTE instruction */ #define X86_FEATURE_MOVDIRI (16*32+27) /* MOVDIRI instruction */ +#define X86_FEATURE_MOVDIR64B (16*32+28) /* MOVDIR64B instruction */ /* AMD-defined CPU features, CPUID level 0x80000007 (EBX), word 17 */ #define X86_FEATURE_OVERFLOW_RECOV (17*32+ 0) /* MCA overflow recovery support */
