[PATCH] Make cpu_relax() imply barrier() on all arches
During the recent discussion of taking 'volatile' off of the spinlock, I
noticed that while most arches #define cpu_relax() such that it implies
barrier(), some arches define cpu_relax() to be empty.
This patch changes the definition of cpu_relax() for frv, h8300, m68knommu,
sh, sh64, v850 and xtensa from an empty while(0) to the compiler barrier().
Signed-off-by: Chase Venters <chase.venters@clientec.com>
Acked-by: Arjan van de Ven <arjan@Linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-sh64/processor.h b/include/asm-sh64/processor.h
index 1bf252d..eb2bee4 100644
--- a/include/asm-sh64/processor.h
+++ b/include/asm-sh64/processor.h
@@ -22,6 +22,7 @@
#include <asm/cache.h>
#include <asm/registers.h>
#include <linux/threads.h>
+#include <linux/compiler.h>
/*
* Default implementation of macro that returns current
@@ -279,7 +280,7 @@
#define KSTK_EIP(tsk) ((tsk)->thread.pc)
#define KSTK_ESP(tsk) ((tsk)->thread.sp)
-#define cpu_relax() do { } while (0)
+#define cpu_relax() barrier()
#endif /* __ASSEMBLY__ */
#endif /* __ASM_SH64_PROCESSOR_H */