m68knommu: avoid unneccessary use of xchg() in set_mb()
Avoid unneccessary use of xchg() in set_mb().
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-m68knommu/system.h b/include/asm-m68knommu/system.h
index 039ab3f..64c6443 100644
--- a/include/asm-m68knommu/system.h
+++ b/include/asm-m68knommu/system.h
@@ -104,7 +104,7 @@
#define mb() asm volatile ("" : : :"memory")
#define rmb() asm volatile ("" : : :"memory")
#define wmb() asm volatile ("" : : :"memory")
-#define set_mb(var, value) do { xchg(&var, value); } while (0)
+#define set_mb(var, value) ({ (var) = (value); wmb(); })
#ifdef CONFIG_SMP
#define smp_mb() mb()
