From 434b6acc31302b37031674af104f45eb4e7a1fc1 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 21 Jun 2018 13:13:12 +0100 Subject: atomics/alpha: Define atomic64_fetch_add_unless() As a step towards unifying the atomic/atomic64/atomic_long APIs, this patch converts the arch/alpha implementation of atomic64_add_unless() into an implementation of atomic64_fetch_add_unless(). A wrapper in 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 Reviewed-by: Will Deacon Acked-by: Peter Zijlstra (Intel) Cc: Boqun Feng Cc: Ivan Kokshaysky Cc: Linus Torvalds Cc: Matt Turner Cc: Richard Henderson Cc: Thomas Gleixner Link: https://lore.kernel.org/lkml/20180621121321.4761-10-mark.rutland@arm.com Signed-off-by: Ingo Molnar --- arch/alpha/include/asm/atomic.h | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) (limited to 'arch/alpha') diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h index 4a800a3424a3..cc486dbb3837 100644 --- a/arch/alpha/include/asm/atomic.h +++ b/arch/alpha/include/asm/atomic.h @@ -238,35 +238,36 @@ static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u) #define atomic_fetch_add_unless atomic_fetch_add_unless /** - * atomic64_add_unless - add unless the number is a given value + * atomic64_fetch_add_unless - add unless the number is a given value * @v: pointer of type atomic64_t * @a: the amount to add to v... * @u: ...unless v is equal to u. * * Atomically adds @a to @v, so long as it was not @u. - * Returns true iff @v was not @u. + * Returns the old value of @v. */ -static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) +static __inline__ long atomic64_fetch_add_unless(atomic64_t *v, long a, long u) { - long c, tmp; + long c, new, old; smp_mb(); __asm__ __volatile__( - "1: ldq_l %[tmp],%[mem]\n" - " cmpeq %[tmp],%[u],%[c]\n" - " addq %[tmp],%[a],%[tmp]\n" + "1: ldq_l %[old],%[mem]\n" + " cmpeq %[old],%[u],%[c]\n" + " addq %[old],%[a],%[new]\n" " bne %[c],2f\n" - " stq_c %[tmp],%[mem]\n" - " beq %[tmp],3f\n" + " stq_c %[new],%[mem]\n" + " beq %[new],3f\n" "2:\n" ".subsection 2\n" "3: br 1b\n" ".previous" - : [tmp] "=&r"(tmp), [c] "=&r"(c) + : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c) : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u) : "memory"); smp_mb(); - return !c; + return old; } +#define atomic64_fetch_add_unless atomic64_fetch_add_unless /* * atomic64_dec_if_positive - decrement by 1 if old value positive -- cgit