x86 & generic: change to __builtin_prefetch()

gcc 3.2+ supports __builtin_prefetch, so it's possible to use it on all
architectures. Change the generic fallback in linux/prefetch.h to use it
instead of noping it out. gcc should do the right thing when the
architecture doesn't support prefetching

Undefine the x86-64 inline assembler version and use the fallback.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 0 insertions, 6 deletions

diff --git a/include/asm-x86/processor_64.h b/include/asm-x86/processor_64.h
index f422becbddd9..398c39160fce 100644
--- a/include/asm-x86/processor_64.h
+++ b/include/asm-x86/processor_64.h
@@ -390,12 +390,6 @@ static inline void sync_core(void)
         asm volatile("cpuid" : "=a" (tmp) : "0" (1) : "ebx","ecx","edx","memory");
 } 
 
-#define ARCH_HAS_PREFETCH
-static inline void prefetch(void *x) 
-{ 
-        asm volatile("prefetcht0 (%0)" :: "r" (x));
-} 
-
 #define ARCH_HAS_PREFETCHW 1
 static inline void prefetchw(void *x) 
 {