diff options
| author | Vineet Gupta <[email protected]> | 2016-10-07 17:02:07 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2016-10-07 18:46:30 -0700 |
| commit | 445ed0a0eac50d2a76441278a084554a4b9dcfda (patch) | |
| tree | f3a8477d8dbe38e31a9297ca0d3a20b925b82bf8 | |
| parent | 1061b0d21e16550e7d7893a5deee2e49ea3990ad (diff) | |
ia64: implement atomic64_dec_if_positive
This is based on s390 version and needed to get rid of
CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Vineet Gupta <[email protected]>
Reported-by: kbuild test robot <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | arch/ia64/include/asm/atomic.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/atomic.h b/arch/ia64/include/asm/atomic.h index f565ad376142..65d4bb2b6685 100644 --- a/arch/ia64/include/asm/atomic.h +++ b/arch/ia64/include/asm/atomic.h @@ -269,6 +269,22 @@ static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0) +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; +} + /* * Atomically add I to V and return TRUE if the resulting value is * negative. |