x86: Add support for the clflushopt instruction

[mirror_ubuntu-artful-kernel.git] / arch / x86 / include / asm / special_insns.h

diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 645cad2c95ff9c87ebd0592c95e891b7a53290fe..e820c080a4e99e45354fc7b6e5720d9f1933b241 100644 (file)
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -191,6 +191,14 @@ static inline void clflush(volatile void *__p)
        asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p));
 }
 
+static inline void clflushopt(volatile void *__p)
+{
+       alternative_io(".byte " __stringify(NOP_DS_PREFIX) "; clflush %P0",
+                      ".byte 0x66; clflush %P0",
+                      X86_FEATURE_CLFLUSHOPT,
+                      "+m" (*(volatile char __force *)__p));
+}
+
 #define nop() asm volatile ("nop")