diff options
author | Mark Rutland <mark.rutland@arm.com> | 2018-06-21 14:13:11 +0200 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2018-06-21 14:25:21 +0200 |
commit | 00b808ab79ead372daf1a0682d1ef271599c0b55 (patch) | |
tree | b6b2384e169533b9f40e213f7cb49cab190c23f5 /lib/atomic64.c | |
parent | atomics: Prepare for atomic64_fetch_add_unless() (diff) | |
download | linux-00b808ab79ead372daf1a0682d1ef271599c0b55.tar.xz linux-00b808ab79ead372daf1a0682d1ef271599c0b55.zip |
atomics/generic: Define atomic64_fetch_add_unless()
As a step towards unifying the atomic/atomic64/atomic_long APIs, this
patch converts the generic implementation of atomic64_add_unless() into
a generic implementation of atomic64_fetch_add_unless().
A wrapper in <linux/atomic.h> will build atomic_add_unless() atop of
this, provided it is given a preprocessor definition.
No functional change is intended as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-9-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'lib/atomic64.c')
-rw-r--r-- | lib/atomic64.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/lib/atomic64.c b/lib/atomic64.c index 4230f4b8906c..1d91e31eceec 100644 --- a/lib/atomic64.c +++ b/lib/atomic64.c @@ -178,18 +178,18 @@ long long atomic64_xchg(atomic64_t *v, long long new) } EXPORT_SYMBOL(atomic64_xchg); -bool atomic64_add_unless(atomic64_t *v, long long a, long long u) +long long atomic64_fetch_add_unless(atomic64_t *v, long long a, long long u) { unsigned long flags; raw_spinlock_t *lock = lock_addr(v); - bool ret = false; + long long val; raw_spin_lock_irqsave(lock, flags); - if (v->counter != u) { + val = v->counter; + if (val != u) v->counter += a; - ret = true; - } raw_spin_unlock_irqrestore(lock, flags); - return ret; + + return val; } -EXPORT_SYMBOL(atomic64_add_unless); +EXPORT_SYMBOL(atomic64_fetch_add_unless); |