[PATCH] mutex subsystem, add atomic_xchg() to all arches

add atomic_xchg() to all the architectures. Needed by the new mutex code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/asm-xtensa/atomic.h b/include/asm-xtensa/atomic.h
index e2ce06b101ad..fe105a123924 100644
--- a/include/asm-xtensa/atomic.h
+++ b/include/asm-xtensa/atomic.h
@@ -224,6 +224,7 @@ static inline int atomic_sub_return(int i, atomic_t * v)
 #define atomic_add_negative(i,v) (atomic_add_return((i),(v)) < 0)
 
 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
 
 /**
  * atomic_add_unless - add unless the number is a given value