Commit-ID: ace6485a03266cc3c198ce8e927a1ce0ce139699 Gitweb: https://git.kernel.org/tip/ace6485a03266cc3c198ce8e927a1ce0ce139699 Author: Fenghua Yu <fenghua...@intel.com> AuthorDate: Wed, 24 Oct 2018 14:57:17 -0700 Committer: Ingo Molnar <mi...@kernel.org> 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 <fenghua...@intel.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Ashok Raj <ashok....@intel.com> Cc: Borislav Petkov <b...@alien8.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Ravi V Shankar <ravi.v.shan...@intel.com> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/1540418237-125817-3-git-send-email-fenghua...@intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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 */
