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Message-ID: <20230731084458.28096-1-ubizjak@gmail.com>
Date: Mon, 31 Jul 2023 10:42:23 +0200
From: Uros Bizjak <ubizjak@...il.com>
To: loongarch@...ts.linux.dev, linux-mips@...r.kernel.org,
x86@...nel.org, linux-arch@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Uros Bizjak <ubizjak@...il.com>, Will Deacon <will@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Boqun Feng <boqun.feng@...il.com>,
Mark Rutland <mark.rutland@....com>,
Richard Henderson <richard.henderson@...aro.org>,
Ivan Kokshaysky <ink@...assic.park.msu.ru>,
Matt Turner <mattst88@...il.com>,
Huacai Chen <chenhuacai@...nel.org>,
WANG Xuerui <kernel@...0n.name>,
Jiaxun Yang <jiaxun.yang@...goat.com>,
Jun Yi <yijun@...ngson.cn>,
Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
Michael Ellerman <mpe@...erman.id.au>,
Nicholas Piggin <npiggin@...il.com>,
Christophe Leroy <christophe.leroy@...roup.eu>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"H. Peter Anvin" <hpa@...or.com>
Subject: [PATCH] locking/arch: Rewrite local_add_unless as static inline function
Rewrite local_add_unless as a static inline function with boolean
return value, similar to arch_atomic_add_unless arch fallbacks.
The function is currently unused.
Cc: Will Deacon <will@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Boqun Feng <boqun.feng@...il.com>
Cc: Mark Rutland <mark.rutland@....com>
Cc: Richard Henderson <richard.henderson@...aro.org>
Cc: Ivan Kokshaysky <ink@...assic.park.msu.ru>
Cc: Matt Turner <mattst88@...il.com>
Cc: Huacai Chen <chenhuacai@...nel.org>
Cc: WANG Xuerui <kernel@...0n.name>
Cc: Jiaxun Yang <jiaxun.yang@...goat.com>
Cc: Jun Yi <yijun@...ngson.cn>
Cc: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
Cc: Michael Ellerman <mpe@...erman.id.au>
Cc: Nicholas Piggin <npiggin@...il.com>
Cc: Christophe Leroy <christophe.leroy@...roup.eu>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: "H. Peter Anvin" <hpa@...or.com>
Signed-off-by: Uros Bizjak <ubizjak@...il.com>
---
arch/alpha/include/asm/local.h | 33 +++++++++++++++---------------
arch/loongarch/include/asm/local.h | 27 ++++++++++++++----------
arch/mips/include/asm/local.h | 27 ++++++++++++++----------
arch/powerpc/include/asm/local.h | 12 +++++------
arch/x86/include/asm/local.h | 33 +++++++++++++++---------------
5 files changed, 70 insertions(+), 62 deletions(-)
diff --git a/arch/alpha/include/asm/local.h b/arch/alpha/include/asm/local.h
index 0fcaad642cc3..88eb398947a5 100644
--- a/arch/alpha/include/asm/local.h
+++ b/arch/alpha/include/asm/local.h
@@ -65,28 +65,27 @@ static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
/**
- * local_add_unless - add unless the number is a given value
+ * local_add_unless - add unless the number is already a given value
* @l: pointer of type local_t
* @a: the amount to add to l...
* @u: ...unless l is equal to u.
*
- * Atomically adds @a to @l, so long as it was not @u.
- * Returns non-zero if @l was not @u, and zero otherwise.
+ * Atomically adds @a to @l, if @v was not already @u.
+ * Returns true if the addition was done.
*/
-#define local_add_unless(l, a, u) \
-({ \
- long c, old; \
- c = local_read(l); \
- for (;;) { \
- if (unlikely(c == (u))) \
- break; \
- old = local_cmpxchg((l), c, c + (a)); \
- if (likely(old == c)) \
- break; \
- c = old; \
- } \
- c != (u); \
-})
+static __inline__ bool
+local_add_unless(local_t *l, long a, long u)
+{
+ long c = local_read(l);
+
+ do {
+ if (unlikely(c == u))
+ return false;
+ } while (!local_try_cmpxchg(l, &c, c + a));
+
+ return true;
+}
+
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
#define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
diff --git a/arch/loongarch/include/asm/local.h b/arch/loongarch/include/asm/local.h
index 83e995b30e47..15bc3579f16c 100644
--- a/arch/loongarch/include/asm/local.h
+++ b/arch/loongarch/include/asm/local.h
@@ -70,22 +70,27 @@ static inline bool local_try_cmpxchg(local_t *l, long *old, long new)
#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
/**
- * local_add_unless - add unless the number is a given value
+ * local_add_unless - add unless the number is already a given value
* @l: pointer of type local_t
* @a: the amount to add to l...
* @u: ...unless l is equal to u.
*
- * Atomically adds @a to @l, so long as it was not @u.
- * Returns non-zero if @l was not @u, and zero otherwise.
+ * Atomically adds @a to @l, if @v was not already @u.
+ * Returns true if the addition was done.
*/
-#define local_add_unless(l, a, u) \
-({ \
- long c, old; \
- c = local_read(l); \
- while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
- c = old; \
- c != (u); \
-})
+static inline bool
+local_add_unless(local_t *l, long a, long u)
+{
+ long c = local_read(l);
+
+ do {
+ if (unlikely(c == u))
+ return false;
+ } while (!local_try_cmpxchg(l, &c, c + a));
+
+ return true;
+}
+
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
#define local_dec_return(l) local_sub_return(1, (l))
diff --git a/arch/mips/include/asm/local.h b/arch/mips/include/asm/local.h
index 5daf6fe8e3e9..90435158a083 100644
--- a/arch/mips/include/asm/local.h
+++ b/arch/mips/include/asm/local.h
@@ -108,22 +108,27 @@ static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
/**
- * local_add_unless - add unless the number is a given value
+ * local_add_unless - add unless the number is already a given value
* @l: pointer of type local_t
* @a: the amount to add to l...
* @u: ...unless l is equal to u.
*
- * Atomically adds @a to @l, so long as it was not @u.
- * Returns non-zero if @l was not @u, and zero otherwise.
+ * Atomically adds @a to @l, if @v was not already @u.
+ * Returns true if the addition was done.
*/
-#define local_add_unless(l, a, u) \
-({ \
- long c, old; \
- c = local_read(l); \
- while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
- c = old; \
- c != (u); \
-})
+static __inline__ bool
+local_add_unless(local_t *l, long a, long u)
+{
+ long c = local_read(l);
+
+ do {
+ if (unlikely(c == u))
+ return false;
+ } while (!local_try_cmpxchg(l, &c, c + a));
+
+ return true;
+}
+
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
#define local_dec_return(l) local_sub_return(1, (l))
diff --git a/arch/powerpc/include/asm/local.h b/arch/powerpc/include/asm/local.h
index 45492fb5bf22..ec6ced6d7ced 100644
--- a/arch/powerpc/include/asm/local.h
+++ b/arch/powerpc/include/asm/local.h
@@ -115,23 +115,23 @@ static __inline__ long local_xchg(local_t *l, long n)
}
/**
- * local_add_unless - add unless the number is a given value
+ * local_add_unless - add unless the number is already a given value
* @l: pointer of type local_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
- * Atomically adds @a to @l, so long as it was not @u.
- * Returns non-zero if @l was not @u, and zero otherwise.
+ * Atomically adds @a to @l, if @v was not already @u.
+ * Returns true if the addition was done.
*/
-static __inline__ int local_add_unless(local_t *l, long a, long u)
+static __inline__ bool local_add_unless(local_t *l, long a, long u)
{
unsigned long flags;
- int ret = 0;
+ bool ret = false;
powerpc_local_irq_pmu_save(flags);
if (l->v != u) {
l->v += a;
- ret = 1;
+ ret = true;
}
powerpc_local_irq_pmu_restore(flags);
diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
index 56d4ef604b91..46ce92d4e556 100644
--- a/arch/x86/include/asm/local.h
+++ b/arch/x86/include/asm/local.h
@@ -135,28 +135,27 @@ static inline bool local_try_cmpxchg(local_t *l, long *old, long new)
#define local_xchg(l, n) (xchg(&((l)->a.counter), (n)))
/**
- * local_add_unless - add unless the number is a given value
+ * local_add_unless - add unless the number is already a given value
* @l: pointer of type local_t
* @a: the amount to add to l...
* @u: ...unless l is equal to u.
*
- * Atomically adds @a to @l, so long as it was not @u.
- * Returns non-zero if @l was not @u, and zero otherwise.
+ * Atomically adds @a to @l, if @v was not already @u.
+ * Returns true if the addition was done.
*/
-#define local_add_unless(l, a, u) \
-({ \
- long c, old; \
- c = local_read((l)); \
- for (;;) { \
- if (unlikely(c == (u))) \
- break; \
- old = local_cmpxchg((l), c, c + (a)); \
- if (likely(old == c)) \
- break; \
- c = old; \
- } \
- c != (u); \
-})
+static __always_inline bool
+local_add_unless(local_t *l, long a, long u)
+{
+ long c = local_read(l);
+
+ do {
+ if (unlikely(c == u))
+ return false;
+ } while (!local_try_cmpxchg(l, &c, c + a));
+
+ return true;
+}
+
#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
/* On x86_32, these are no better than the atomic variants.
--
2.41.0
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