diff options
| author | Vineet Gupta <Vineet.Gupta1@synopsys.com> | 2016-10-08 02:02:07 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-08 03:46:30 +0200 |
| commit | 445ed0a0eac50d2a76441278a084554a4b9dcfda (patch) | |
| tree | f3a8477d8dbe38e31a9297ca0d3a20b925b82bf8 /arch/ia64 | |
| parent | linux/mm.h: canonicalize macro PAGE_ALIGNED() definition (diff) | |
| download | linux-445ed0a0eac50d2a76441278a084554a4b9dcfda.tar.xz linux-445ed0a0eac50d2a76441278a084554a4b9dcfda.zip | |
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/1473703083-8625-2-git-send-email-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/ia64')
| -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. |