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author | Len Brown <len.brown@intel.com> | 2005-12-07 01:31:30 +0300 |
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committer | Len Brown <len.brown@intel.com> | 2005-12-07 01:31:30 +0300 |
commit | 3d5271f9883cba7b54762bc4fe027d4172f06db7 (patch) | |
tree | ab8a881a14478598a0c8bda0d26c62cdccfffd6d /include/asm-i386/atomic.h | |
parent | 378b2556f4e09fa6f87ff0cb5c4395ff28257d02 (diff) | |
parent | 9115a6c787596e687df03010d97fccc5e0762506 (diff) | |
download | linux-3d5271f9883cba7b54762bc4fe027d4172f06db7.tar.xz |
Pull release into acpica branch
Diffstat (limited to 'include/asm-i386/atomic.h')
-rw-r--r-- | include/asm-i386/atomic.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/asm-i386/atomic.h b/include/asm-i386/atomic.h index 509720be772a..c68557aa04b2 100644 --- a/include/asm-i386/atomic.h +++ b/include/asm-i386/atomic.h @@ -215,6 +215,27 @@ static __inline__ int atomic_sub_return(int i, atomic_t *v) return atomic_add_return(-i,v); } +#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new)) + +/** + * 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_inc_return(v) (atomic_add_return(1,v)) #define atomic_dec_return(v) (atomic_sub_return(1,v)) |