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author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-10-18 01:09:09 +0200 |
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committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-10-18 01:12:33 +0200 |
commit | 0f8f86c7bdd1c954fbe153af437a0d91a6c5721a (patch) | |
tree | 94a8d419a470a4f9852ca397bb9bbe48db92ff5c /arch/arm/include/asm/atomic.h | |
parent | Merge branch 'linus' into tracing/hw-breakpoints (diff) | |
parent | perf tools: Move dereference after NULL test (diff) | |
download | linux-dev-0f8f86c7bdd1c954fbe153af437a0d91a6c5721a.tar.xz linux-dev-0f8f86c7bdd1c954fbe153af437a0d91a6c5721a.zip |
Merge commit 'perf/core' into perf/hw-breakpoint
Conflicts:
kernel/Makefile
kernel/trace/Makefile
kernel/trace/trace.h
samples/Makefile
Merge reason: We need to be uptodate with the perf events development
branch because we plan to rewrite the breakpoints API on top of
perf events.
Diffstat (limited to 'arch/arm/include/asm/atomic.h')
-rw-r--r-- | arch/arm/include/asm/atomic.h | 26 |
1 files changed, 7 insertions, 19 deletions
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h index 9ed2377fe8e5..d0daeab2234e 100644 --- a/arch/arm/include/asm/atomic.h +++ b/arch/arm/include/asm/atomic.h @@ -19,31 +19,21 @@ #ifdef __KERNEL__ +/* + * On ARM, ordinary assignment (str instruction) doesn't clear the local + * strex/ldrex monitor on some implementations. The reason we can use it for + * atomic_set() is the clrex or dummy strex done on every exception return. + */ #define atomic_read(v) ((v)->counter) +#define atomic_set(v,i) (((v)->counter) = (i)) #if __LINUX_ARM_ARCH__ >= 6 /* * ARMv6 UP and SMP safe atomic ops. We use load exclusive and * store exclusive to ensure that these are atomic. We may loop - * to ensure that the update happens. Writing to 'v->counter' - * without using the following operations WILL break the atomic - * nature of these ops. + * to ensure that the update happens. */ -static inline void atomic_set(atomic_t *v, int i) -{ - unsigned long tmp; - - __asm__ __volatile__("@ atomic_set\n" -"1: ldrex %0, [%1]\n" -" strex %0, %2, [%1]\n" -" teq %0, #0\n" -" bne 1b" - : "=&r" (tmp) - : "r" (&v->counter), "r" (i) - : "cc"); -} - static inline void atomic_add(int i, atomic_t *v) { unsigned long tmp; @@ -163,8 +153,6 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) #error SMP not supported on pre-ARMv6 CPUs #endif -#define atomic_set(v,i) (((v)->counter) = (i)) - static inline int atomic_add_return(int i, atomic_t *v) { unsigned long flags; |