[PATCH] atomic: cmpxchg
Introduce an atomic_cmpxchg operation.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-m68k/atomic.h b/include/asm-m68k/atomic.h
index 38f3043..b821975 100644
--- a/include/asm-m68k/atomic.h
+++ b/include/asm-m68k/atomic.h
@@ -139,6 +139,8 @@
__asm__ __volatile__("orl %1,%0" : "+m" (*v) : "id" (mask));
}
+#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+
/* Atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()