From: Mark Rutland <mark.rutland@arm.com>
To: linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Boqun Feng <boqun.feng@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Will Deacon <will.deacon@arm.com>,
Russell King <linux@armlinux.org.uk>
Subject: [PATCH 09/13] atomics/arm: define atomic64_fetch_add_unless()
Date: Wed, 23 May 2018 14:35:29 +0100 [thread overview]
Message-ID: <20180523133533.1076-10-mark.rutland@arm.com> (raw)
In-Reply-To: <20180523133533.1076-1-mark.rutland@arm.com>
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>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
---
arch/arm/include/asm/atomic.h | 20 ++++++++++----------
1 file 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))
--
2.11.0
next prev parent reply other threads:[~2018-05-23 13:36 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-23 13:35 [PATCH 00/13] atomics: API cleanups Mark Rutland
2018-05-23 13:35 ` [PATCH 01/13] atomics/treewide: s/__atomic_add_unless/atomic_fetch_add_unless/ Mark Rutland
2018-05-23 14:01 ` Geert Uytterhoeven
2018-05-23 13:35 ` [PATCH 02/13] atomics/treewide: remove redundant atomic_inc_not_zero() definitions Mark Rutland
2018-05-24 8:26 ` Mark Rutland
2018-05-23 13:35 ` [PATCH 03/13] atomics/treewide: make atomic64_inc_not_zero() optional Mark Rutland
2018-05-23 13:35 ` [PATCH 04/13] atomics/treewide: make atomic_fetch_add_unless() optional Mark Rutland
2018-05-23 14:02 ` Geert Uytterhoeven
2018-05-23 13:35 ` [PATCH 05/13] atomics: prepare for atomic64_fetch_add_unless() Mark Rutland
2018-05-23 13:35 ` [PATCH 06/13] atomics/generic: define atomic64_fetch_add_unless() Mark Rutland
2018-05-23 13:35 ` [PATCH 07/13] atomics/alpha: " Mark Rutland
2018-05-23 13:35 ` [PATCH 08/13] atomics/arc: " Mark Rutland
2018-05-23 13:35 ` Mark Rutland [this message]
2018-05-23 13:35 ` [PATCH 10/13] atomics/powerpc: " Mark Rutland
2018-05-24 1:50 ` Michael Ellerman
2018-05-23 13:35 ` [PATCH 11/13] atomics/riscv: " Mark Rutland
2018-05-23 13:35 ` [PATCH 12/13] atomics/treewide: make atomic64_fetch_add_unless() optional Mark Rutland
2018-05-23 13:35 ` [PATCH 13/13] atomics/treewide: make test ops optional Mark Rutland
2018-05-23 14:03 ` Geert Uytterhoeven
2018-05-29 9:11 ` Mark Rutland
2018-05-29 9:57 ` Mark Rutland
2018-05-29 10:49 ` Peter Zijlstra
2018-05-23 17:18 ` [PATCH 00/13] atomics: API cleanups Peter Zijlstra
2018-05-24 8:27 ` Mark Rutland
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