diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2018-06-21 13:13:10 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-06-21 14:22:34 +0200 |
| commit | 0ae1d994020d75ac065fd42ac4cbf5ac6ce9b255 (patch) | |
| tree | cf2d922b4d55a708fd50f77bd9c08bc4d002bd15 /include/linux/atomic.h | |
| parent | eccc2da8c03f316bba202e15af2be4615f461900 (diff) | |
atomics: Prepare for atomic64_fetch_add_unless()
Currently all architectures must implement atomic_fetch_add_unless(),
with common code providing atomic_add_unless(). Architectures must also
implement atomic64_add_unless() directly, with no corresponding
atomic64_fetch_add_unless().
This divergence is unfortunate, and means that the APIs for atomic_t,
atomic64_t, and atomic_long_t differ.
In preparation for unifying things, with architectures providing
atomic64_fetch_add_unless, this patch adds a generic
atomic64_add_unless() which will use atomic64_fetch_add_unless(). The
instrumented atomics are updated to take this case into account.
There should be no functional change 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: Albert Ou <albert@sifive.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Link: https://lore.kernel.org/lkml/20180621121321.4761-8-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/atomic.h')
| -rw-r--r-- | include/linux/atomic.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/atomic.h b/include/linux/atomic.h index b89ba36cab94..3c03de648007 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -1043,6 +1043,22 @@ static inline int atomic_dec_if_positive(atomic_t *v) #endif /* atomic64_try_cmpxchg */ /** + * atomic64_add_unless - add unless the number is already 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, if @v was not already @u. + * Returns true if the addition was done. + */ +#ifdef atomic64_fetch_add_unless +static inline bool atomic64_add_unless(atomic64_t *v, long long a, long long u) +{ + return atomic64_fetch_add_unless(v, a, u) != u; +} +#endif + +/** * atomic64_inc_not_zero - increment unless the number is zero * @v: pointer of type atomic64_t * |