[PATCH v2] locking/atomics/powerpc: Move cmpxchg helpers to asm/cmpxchg.h and define the full set of cmpxchg APIs
From: Boqun Feng <hidden>
Date: 2018-05-07 13:26:59
Also in:
lkml
Subsystem:
atomic infrastructure, linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Will Deacon, Peter Zijlstra, Boqun Feng, Madhavan Srinivasan, Linus Torvalds
Move PowerPC's __op_{acqurie,release}() from atomic.h to
cmpxchg.h (in arch/powerpc/include/asm), plus use them to
define these two methods:
#define cmpxchg_release __op_release(cmpxchg, __VA_ARGS__);
#define cmpxchg64_release __op_release(cmpxchg64, __VA_ARGS__);
... the idea is to generate all these methods in cmpxchg.h and to define the full
array of atomic primitives, including the cmpxchg_release() methods which were
defined by the generic code before.
Also define the atomic[64]_() variants explicitly.
This ensures that all these low level cmpxchg APIs are defined in
PowerPC headers, with no generic header fallbacks.
Also remove the duplicate definitions of atomic_xchg() and
atomic64_xchg() in asm/atomic.h: they could be generated via the generic
atomic.h header using _relaxed() primitives. This helps ppc adopt the
upcoming change of generic atomic.h header.
No change in functionality or code generation.
Signed-off-by: Boqun Feng <redacted>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <redacted>
Cc: aryabinin at virtuozzo.com
Cc: catalin.marinas at arm.com
Cc: dvyukov at google.com
Cc: linux-arm-kernel at lists.infradead.org
Cc: will.deacon at arm.com
---
v1 --> v2:
remove duplicate definitions for atomic*_xchg() for future
change
Ingo,
I also remove the link and your SoB because I think your bot
could add them automatically.
arch/powerpc/include/asm/atomic.h | 24 ++++--------------------
arch/powerpc/include/asm/cmpxchg.h | 24 ++++++++++++++++++++++++
2 files changed, 28 insertions(+), 20 deletions(-)
diff --git a/arch/powerpc/include/asm/atomic.h b/arch/powerpc/include/asm/atomic.h
index 682b3e6a1e21..583837a41bcc 100644
--- a/arch/powerpc/include/asm/atomic.h
+++ b/arch/powerpc/include/asm/atomic.h@@ -13,24 +13,6 @@ #define ATOMIC_INIT(i) { (i) } -/* - * Since *_return_relaxed and {cmp}xchg_relaxed are implemented with - * a "bne-" instruction at the end, so an isync is enough as a acquire barrier - * on the platform without lwsync. - */ -#define __atomic_op_acquire(op, args...) \ -({ \ - typeof(op##_relaxed(args)) __ret = op##_relaxed(args); \ - __asm__ __volatile__(PPC_ACQUIRE_BARRIER "" : : : "memory"); \ - __ret; \ -}) - -#define __atomic_op_release(op, args...) \ -({ \ - __asm__ __volatile__(PPC_RELEASE_BARRIER "" : : : "memory"); \ - op##_relaxed(args); \ -}) - static __inline__ int atomic_read(const atomic_t *v) { int t;
@@ -213,8 +195,9 @@ static __inline__ int atomic_dec_return_relaxed(atomic_t *v) cmpxchg_relaxed(&((v)->counter), (o), (n)) #define atomic_cmpxchg_acquire(v, o, n) \ cmpxchg_acquire(&((v)->counter), (o), (n)) +#define atomic_cmpxchg_release(v, o, n) \ + cmpxchg_release(&((v)->counter), (o), (n)) -#define atomic_xchg(v, new) (xchg(&((v)->counter), new)) #define atomic_xchg_relaxed(v, new) xchg_relaxed(&((v)->counter), (new)) /**
@@ -519,8 +502,9 @@ static __inline__ long atomic64_dec_if_positive(atomic64_t *v) cmpxchg_relaxed(&((v)->counter), (o), (n)) #define atomic64_cmpxchg_acquire(v, o, n) \ cmpxchg_acquire(&((v)->counter), (o), (n)) +#define atomic64_cmpxchg_release(v, o, n) \ + cmpxchg_release(&((v)->counter), (o), (n)) -#define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) #define atomic64_xchg_relaxed(v, new) xchg_relaxed(&((v)->counter), (new)) /**
diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h
index 9b001f1f6b32..e27a612b957f 100644
--- a/arch/powerpc/include/asm/cmpxchg.h
+++ b/arch/powerpc/include/asm/cmpxchg.h@@ -8,6 +8,24 @@ #include <asm/asm-compat.h> #include <linux/bug.h> +/* + * Since *_return_relaxed and {cmp}xchg_relaxed are implemented with + * a "bne-" instruction at the end, so an isync is enough as a acquire barrier + * on the platform without lwsync. + */ +#define __atomic_op_acquire(op, args...) \ +({ \ + typeof(op##_relaxed(args)) __ret = op##_relaxed(args); \ + __asm__ __volatile__(PPC_ACQUIRE_BARRIER "" : : : "memory"); \ + __ret; \ +}) + +#define __atomic_op_release(op, args...) \ +({ \ + __asm__ __volatile__(PPC_RELEASE_BARRIER "" : : : "memory"); \ + op##_relaxed(args); \ +}) + #ifdef __BIG_ENDIAN #define BITOFF_CAL(size, off) ((sizeof(u32) - size - off) * BITS_PER_BYTE) #else
@@ -512,6 +530,9 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new, (unsigned long)_o_, (unsigned long)_n_, \ sizeof(*(ptr))); \ }) + +#define cmpxchg_release(...) __atomic_op_release(cmpxchg, __VA_ARGS__) + #ifdef CONFIG_PPC64 #define cmpxchg64(ptr, o, n) \ ({ \
@@ -533,6 +554,9 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new, BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ cmpxchg_acquire((ptr), (o), (n)); \ }) + +#define cmpxchg64_release(...) __atomic_op_release(cmpxchg64, __VA_ARGS__) + #else #include <asm-generic/cmpxchg-local.h> #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
--
2.16.2