diff options
| author | Arun Sharma <asharma@fb.com> | 2011-07-26 16:09:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-26 16:49:47 -0700 |
| commit | f24219b4e90cf70ec4a211b17fbabc725a0ddf3c (patch) | |
| tree | c1c753bd425d61a5094995d9835b23b46383d9b2 /include | |
| parent | 60063497a95e716c9a689af3be2687d261f115b4 (diff) | |
| download | lwn-f24219b4e90cf70ec4a211b17fbabc725a0ddf3c.tar.gz lwn-f24219b4e90cf70ec4a211b17fbabc725a0ddf3c.zip | |
atomic: move atomic_add_unless to generic code
This is in preparation for more generic atomic primitives based on
__atomic_add_unless.
Signed-off-by: Arun Sharma <asharma@fb.com>
Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/atomic.h | 4 | ||||
| -rw-r--r-- | include/linux/atomic.h | 14 |
2 files changed, 16 insertions, 2 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h index 7f84414c5f53..bd18bfd78e9b 100644 --- a/include/asm-generic/atomic.h +++ b/include/asm-generic/atomic.h @@ -129,13 +129,13 @@ static inline void atomic_dec(atomic_t *v) #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) -static inline int atomic_add_unless(atomic_t *v, int a, int u) +static inline int __atomic_add_unless(atomic_t *v, int a, int u) { int c, old; c = atomic_read(v); while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c) c = old; - return c != u; + return c; } static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) diff --git a/include/linux/atomic.h b/include/linux/atomic.h index 66fed6364122..d5e167a6a398 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -3,6 +3,20 @@ #include <asm/atomic.h> /** + * atomic_add_unless - add unless the number is already a given value + * @v: pointer of type atomic_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as @v was not already @u. + * Returns non-zero if @v was not @u, and zero otherwise. + */ +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + return __atomic_add_unless(v, a, u) != u; +} + +/** * atomic_inc_not_zero - increment unless the number is zero * @v: pointer of type atomic_t * |