diff options
author | Ingo Molnar <mingo@kernel.org> | 2013-06-19 12:55:31 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2013-06-19 12:55:31 +0200 |
commit | d81344c50824a4d28a9397e97135d60075ac37ff (patch) | |
tree | d25c443fb4a764cd788db857c49dd3d3f8f722d3 /arch/parisc/include/asm/atomic.h | |
parent | 0de358f1c2642710d41190b73fbc295e675c4ab8 (diff) | |
parent | 29bb9e5a75684106a37593ad75ec75ff8312731b (diff) |
Merge branch 'sched/urgent' into sched/core
Merge in fixes before applying ongoing new work.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/parisc/include/asm/atomic.h')
-rw-r--r-- | arch/parisc/include/asm/atomic.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index f38e1984b242..472886ceab1d 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -229,6 +229,29 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) +/* + * atomic64_dec_if_positive - decrement by 1 if old value positive + * @v: pointer of type atomic_t + * + * The function returns the old value of *v minus 1, even if + * the atomic variable, v, was not decremented. + */ +static inline long atomic64_dec_if_positive(atomic64_t *v) +{ + long c, old, dec; + c = atomic64_read(v); + for (;;) { + dec = c - 1; + if (unlikely(dec < 0)) + break; + old = atomic64_cmpxchg((v), c, dec); + if (likely(old == c)) + break; + c = old; + } + return dec; +} + #endif /* !CONFIG_64BIT */ |