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-rw-r--r--arch/x86/include/asm/cpufeature.h1
-rw-r--r--arch/x86/include/asm/special_insns.h14
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 0f7a5a1a8db2..854c04b3c9c2 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -233,6 +233,7 @@
#define X86_FEATURE_SMAP ( 9*32+20) /* Supervisor Mode Access Prevention */
#define X86_FEATURE_PCOMMIT ( 9*32+22) /* PCOMMIT instruction */
#define X86_FEATURE_CLFLUSHOPT ( 9*32+23) /* CLFLUSHOPT instruction */
+#define X86_FEATURE_CLWB ( 9*32+24) /* CLWB instruction */
#define X86_FEATURE_AVX512PF ( 9*32+26) /* AVX-512 Prefetch */
#define X86_FEATURE_AVX512ER ( 9*32+27) /* AVX-512 Exponential and Reciprocal */
#define X86_FEATURE_AVX512CD ( 9*32+28) /* AVX-512 Conflict Detection */
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 2ec1a5392542..aeb4666e0c0a 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -201,6 +201,20 @@ static inline void clflushopt(volatile void *__p)
"+m" (*(volatile char __force *)__p));
}
+static inline void clwb(volatile void *__p)
+{
+ volatile struct { char x[64]; } *p = __p;
+
+ asm volatile(ALTERNATIVE_2(
+ ".byte " __stringify(NOP_DS_PREFIX) "; clflush (%[pax])",
+ ".byte 0x66; clflush (%[pax])", /* clflushopt (%%rax) */
+ X86_FEATURE_CLFLUSHOPT,
+ ".byte 0x66, 0x0f, 0xae, 0x30", /* clwb (%%rax) */
+ X86_FEATURE_CLWB)
+ : [p] "+m" (*p)
+ : [pax] "a" (p));
+}
+
static inline void pcommit_sfence(void)
{
alternative(ASM_NOP7,