[PATCH] atomic: cmpxchg

[linux-3.10.git] / include / asm-cris / atomic.h

diff --git a/include/asm-cris/atomic.h b/include/asm-cris/atomic.h
index 8c2e78304523c24da5904dc9b3d85d2988383979..45891f7de00fc1c58a9bcc48158c75dc2a386746 100644 (file)
--- a/include/asm-cris/atomic.h
+++ b/include/asm-cris/atomic.h
@@ -123,6 +123,19 @@ static inline int atomic_inc_and_test(volatile atomic_t *v)
        return retval;
 }
 
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+       int ret;
+       unsigned long flags;
+
+       cris_atomic_save(v, flags);
+       ret = v->counter;
+       if (likely(ret == old))
+               v->counter = new;
+       cris_atomic_restore(v, flags);
+       return ret;
+}
+
 /* Atomic operations are already serializing */
 #define smp_mb__before_atomic_dec()    barrier()
 #define smp_mb__after_atomic_dec()     barrier()