diff options
Diffstat (limited to 'include/asm-parisc/atomic.h')
| -rw-r--r-- | include/asm-parisc/atomic.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/asm-parisc/atomic.h b/include/asm-parisc/atomic.h index 52c9a45b5f87..983e9a2b6042 100644 --- a/include/asm-parisc/atomic.h +++ b/include/asm-parisc/atomic.h @@ -166,6 +166,25 @@ static __inline__ int atomic_read(const atomic_t *v) /* exported interface */ #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n))) +/** + * atomic_add_unless - add unless the number is 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 it was not @u. + * Returns non-zero if @v was not @u, and zero otherwise. + */ +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + #define atomic_add(i,v) ((void)(__atomic_add_return( ((int)i),(v)))) #define atomic_sub(i,v) ((void)(__atomic_add_return(-((int)i),(v)))) #define atomic_inc(v) ((void)(__atomic_add_return( 1,(v)))) |