[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, 2 insertions, 0 deletions

diff --git a/include/asm-s390/atomic.h b/include/asm-s390/atomic.h
index d82aedf616fe..be6fefe223d6 100644
--- a/include/asm-s390/atomic.h
+++ b/include/asm-s390/atomic.h
@@ -75,6 +75,8 @@ static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
                __CS_LOOP(v, mask, "or");
 }
 
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
 static __inline__ int atomic_cmpxchg(atomic_t *v, int old, int new)
 {
         __asm__ __volatile__("  cs   %0,%3,0(%2)\n"