From 84fb144b928744cea8eb39bb4fbc794fcb749175 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 4 Feb 2008 16:48:00 +0100 Subject: [PATCH] x86: reintroduce volatile keyword in prototype to clflush() The volatile keyword was removed from the clflush() prototype in commit e34907ae180f4fe6c28bb4516c679c2f81b0c9ed; the comment there states: x86: remove volatile keyword from clflush. the p parameter is an explicit memory reference, and is enough to prevent gcc to being nasty here. The volatile seems completely not needed. This reflects incorrect understanding of the function of the volatile keyword there. The purpose of the volatile keyword is informing gcc that it is safe to pass a volatile pointer to this function. Signed-off-by: H. Peter Anvin Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/asm-x86/system.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/asm-x86/system.h b/include/asm-x86/system.h index 428348e990bf..e9c15c97dfe2 100644 --- a/include/asm-x86/system.h +++ b/include/asm-x86/system.h @@ -271,9 +271,9 @@ static inline void native_wbinvd(void) #endif /* __KERNEL__ */ -static inline void clflush(void *__p) +static inline void clflush(volatile void *__p) { - asm volatile("clflush %0" : "+m" (*(char __force *)__p)); + asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p)); } #define nop() __asm__ __volatile__ ("nop") -- 2.20.1