[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>
This commit is contained in:
Nick Piggin
2005-11-13 16:07:24 -08:00
committed by Linus Torvalds
parent 53e86b91b7
commit 4a6dae6d38
23 changed files with 169 additions and 5 deletions

View File

@@ -198,6 +198,8 @@ atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
return retval;
}
#define atomic_cmpxchg(v, o, n) (atomic_compare_and_swap((o), (n), &((v)->counter)))
#define smp_mb__before_atomic_dec() smp_mb()
#define smp_mb__after_atomic_dec() smp_mb()
#define smp_mb__before_atomic_inc() smp_mb()