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>
diff --git a/include/linux/prefetch.h b/include/linux/prefetch.h
index 1adfe66..af7c36a 100644
--- a/include/linux/prefetch.h
+++ b/include/linux/prefetch.h
@@ -34,17 +34,12 @@
*/
-/*
- * These cannot be do{}while(0) macros. See the mental gymnastics in
- * the loop macro.
- */
-
#ifndef ARCH_HAS_PREFETCH
-static inline void prefetch(const void *x) {;}
+#define prefetch(x) __builtin_prefetch(x)
#endif
#ifndef ARCH_HAS_PREFETCHW
-static inline void prefetchw(const void *x) {;}
+#define prefetchw(x) __builtin_prefetch(x,1)
#endif
#ifndef ARCH_HAS_SPINLOCK_PREFETCH