diff options
| author | Mark Rutland <mark.rutland@arm.com> | 2018-06-21 13:13:14 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-06-21 14:25:24 +0200 |
| commit | fee8ca9fa5659d8d79432d38c52fa18da67f1e71 (patch) | |
| tree | dd284e3ae4da0d91ef34be348d3671f5d5986ffb | |
| parent | ab0b910490fef91cd02691d3311f6ebaaed4c196 (diff) | |
| download | linux-fee8ca9fa5659d8d79432d38c52fa18da67f1e71.tar.gz | |
atomics/arm: Define atomic64_fetch_add_unless()
As a step towards unifying the atomic/atomic64/atomic_long APIs, this patch converts the arch/arm implementation of atomic64_add_unless() into an 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: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-12-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/arm/include/asm/atomic.h | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index 74460aa00fa0..852e1fee72b0 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -486,11 +486,11 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v) return result; } -static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u) +static inline long long atomic64_fetch_add_unless(atomic64_t *v, long long a, + long long u) { - long long val; + long long oldval, newval; unsigned long tmp; - int ret = 1; smp_mb(); prefetchw(&v->counter); @@ -499,23 +499,23 @@ static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u) "1: ldrexd %0, %H0, [%4]\n" " teq %0, %5\n" " teqeq %H0, %H5\n" -" moveq %1, #0\n" " beq 2f\n" -" adds %Q0, %Q0, %Q6\n" -" adc %R0, %R0, %R6\n" -" strexd %2, %0, %H0, [%4]\n" +" adds %Q1, %Q0, %Q6\n" +" adc %R1, %R0, %R6\n" +" strexd %2, %1, %H1, [%4]\n" " teq %2, #0\n" " bne 1b\n" "2:" - : "=&r" (val), "+r" (ret), "=&r" (tmp), "+Qo" (v->counter) + : "=&r" (oldval), "=&r" (newval), "=&r" (tmp), "+Qo" (v->counter) : "r" (&v->counter), "r" (u), "r" (a) : "cc"); - if (ret) + if (oldval != u) smp_mb(); - return ret; + return oldval; } +#define atomic64_fetch_add_unless atomic64_fetch_add_unless #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) #define atomic64_inc(v) atomic64_add(1LL, (v)) |