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| author | Nick Piggin <nickpiggin@yahoo.com.au> | 2005-11-13 16:07:24 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-13 18:14:16 -0800 |
| commit | 4a6dae6d382e9edf3ff440b819e554ed706359bc (patch) | |
| tree | 2945a5095973e2ecf05b503d6deb859083045b8e /include/asm-cris | |
| parent | 53e86b91b7ae66d4c2757195cbd42e00d9199cf2 (diff) | |
| download | linux-4a6dae6d382e9edf3ff440b819e554ed706359bc.tar.bz2 | |
[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>
Diffstat (limited to 'include/asm-cris')
| -rw-r--r-- | include/asm-cris/atomic.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/asm-cris/atomic.h b/include/asm-cris/atomic.h index 8c2e78304523..45891f7de00f 100644 --- 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() |