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>,
Will Deacon <will.deacon@arm.com>,
Vineet Gupta <vgupta@synopsys.com>
Subject: [PATCHv2 08/16] atomics/arc: define atomic64_fetch_add_unless()
Date: Tue, 29 May 2018 16:43:38 +0100 [thread overview]
Message-ID: <20180529154346.3168-9-mark.rutland@arm.com> (raw)
In-Reply-To: <20180529154346.3168-1-mark.rutland@arm.com>
As a step towards unifying the atomic/atomic64/atomic_long APIs, this
patch converts the arch/arc 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>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/include/asm/atomic.h | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h
index 60da80481c5d..335ddc21ed03 100644
--- a/arch/arc/include/asm/atomic.h
+++ b/arch/arc/include/asm/atomic.h
@@ -531,41 +531,40 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v)
}
/**
- * 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.
*
- * if (v != u) { v += a; ret = 1} else {ret = 0}
- * Returns 1 iff @v was not @u (i.e. if add actually happened)
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns the old value of @v
*/
-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;
- int op_done;
+ long long old, temp;
smp_mb();
__asm__ __volatile__(
"1: llockd %0, [%2] \n"
- " mov %1, 1 \n"
" brne %L0, %L4, 2f # continue to add since v != u \n"
" breq.d %H0, %H4, 3f # return since v == u \n"
- " mov %1, 0 \n"
"2: \n"
- " add.f %L0, %L0, %L3 \n"
- " adc %H0, %H0, %H3 \n"
- " scondd %0, [%2] \n"
+ " add.f %L1, %L0, %L3 \n"
+ " adc %H1, %H0, %H3 \n"
+ " scondd %1, [%2] \n"
" bnz 1b \n"
"3: \n"
- : "=&r"(val), "=&r" (op_done)
+ : "=&r"(old), "=&r" (temp)
: "r"(&v->counter), "r"(a), "r"(u)
: "cc"); /* memory clobber comes from smp_mb() */
smp_mb();
- return op_done;
+ return old;
}
+#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:[~2018-05-29 15:44 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-29 15:43 [PATCHv2 00/16] atomics: API cleanups Mark Rutland
2018-05-29 15:43 ` [PATCHv2 01/16] atomics/treewide: s/__atomic_add_unless/atomic_fetch_add_unless/ Mark Rutland
2018-06-04 23:24 ` Palmer Dabbelt
2018-05-29 15:43 ` [PATCHv2 02/16] atomics/treewide: remove redundant atomic_inc_not_zero() definitions Mark Rutland
2018-06-04 23:24 ` Palmer Dabbelt
2018-05-29 15:43 ` [PATCHv2 03/16] atomics/treewide: make atomic64_inc_not_zero() optional Mark Rutland
2018-06-04 23:17 ` Palmer Dabbelt
2018-06-05 5:34 ` Mark Rutland
2018-05-29 15:43 ` [PATCHv2 04/16] atomics/treewide: make atomic_fetch_add_unless() optional Mark Rutland
2018-06-04 23:24 ` Palmer Dabbelt
2018-05-29 15:43 ` [PATCHv2 05/16] atomics: prepare for atomic64_fetch_add_unless() Mark Rutland
2018-06-05 9:26 ` Peter Zijlstra
2018-06-05 9:53 ` Mark Rutland
2018-06-05 10:54 ` Michael Ellerman
2018-06-05 11:08 ` Mark Rutland
2018-06-06 8:57 ` Michael Ellerman
2018-05-29 15:43 ` [PATCHv2 06/16] atomics/generic: define atomic64_fetch_add_unless() Mark Rutland
2018-05-29 15:43 ` [PATCHv2 07/16] atomics/alpha: " Mark Rutland
2018-05-29 15:43 ` Mark Rutland [this message]
2018-05-29 15:43 ` [PATCHv2 09/16] atomics/arm: " Mark Rutland
2018-05-29 15:43 ` [PATCHv2 10/16] atomics/powerpc: " Mark Rutland
2018-05-29 15:43 ` [PATCHv2 11/16] atomics/riscv: " Mark Rutland
2018-06-04 23:17 ` Palmer Dabbelt
2018-05-29 15:43 ` [PATCHv2 12/16] atomics/treewide: make atomic64_fetch_add_unless() optional Mark Rutland
2018-05-29 15:43 ` [PATCHv2 13/16] atomics/treewide: make test ops optional Mark Rutland
2018-06-04 23:17 ` Palmer Dabbelt
2018-05-29 15:43 ` [PATCHv2 14/16] atomics/treewide: remove atomic_inc_not_zero_hint() Mark Rutland
2018-05-29 15:43 ` [PATCHv2 15/16] atomics/treewide: make unconditional inc/dec ops optional Mark Rutland
2018-06-04 23:17 ` Palmer Dabbelt
2018-05-29 15:43 ` [PATCHv2 16/16] atomics/treewide: make conditional " Mark Rutland
2018-05-30 11:23 ` [PATCHv2 00/16] atomics: API cleanups Mark Rutland
2018-05-30 13:34 ` Mark Rutland
2018-06-05 9:43 ` Peter Zijlstra
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