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| author | Nick Piggin <npiggin@suse.de> | 2007-10-18 03:06:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-18 14:37:29 -0700 |
| commit | 44086d5286c57c86622dee37684decf32355aa7c (patch) | |
| tree | 7660cc81afd36f3724cab197bc97860e3c20fc80 /include/asm-alpha | |
| parent | 7c29ca5b8d13287ed67d2863f4c5f7bfc1a15279 (diff) | |
| download | linux-44086d5286c57c86622dee37684decf32355aa7c.tar.gz linux-44086d5286c57c86622dee37684decf32355aa7c.tar.bz2 linux-44086d5286c57c86622dee37684decf32355aa7c.zip | |
alpha: lock bitops
Alpha can avoid one mb when acquiring a lock with test_and_set_bit_lock.
[bunk@kernel.org: alpha bitops.h must #include <asm/barrier.h>]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-alpha')
| -rw-r--r-- | include/asm-alpha/bitops.h | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/include/asm-alpha/bitops.h b/include/asm-alpha/bitops.h index f1bbe6cf0e84..381b4f5b4d5d 100644 --- a/include/asm-alpha/bitops.h +++ b/include/asm-alpha/bitops.h @@ -2,6 +2,7 @@ #define _ALPHA_BITOPS_H #include <asm/compiler.h> +#include <asm/barrier.h> /* * Copyright 1994, Linus Torvalds. @@ -69,6 +70,13 @@ clear_bit(unsigned long nr, volatile void * addr) :"Ir" (1UL << (nr & 31)), "m" (*m)); } +static inline void +clear_bit_unlock(unsigned long nr, volatile void * addr) +{ + smp_mb(); + clear_bit(nr, addr); +} + /* * WARNING: non atomic version. */ @@ -81,6 +89,13 @@ __clear_bit(unsigned long nr, volatile void * addr) } static inline void +__clear_bit_unlock(unsigned long nr, volatile void * addr) +{ + smp_mb(); + __clear_bit(nr, addr); +} + +static inline void change_bit(unsigned long nr, volatile void * addr) { unsigned long temp; @@ -139,6 +154,33 @@ test_and_set_bit(unsigned long nr, volatile void *addr) return oldbit != 0; } +static inline int +test_and_set_bit_lock(unsigned long nr, volatile void *addr) +{ + unsigned long oldbit; + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%4\n" + " and %0,%3,%2\n" + " bne %2,2f\n" + " xor %0,%3,%0\n" + " stl_c %0,%1\n" + " beq %0,3f\n" + "2:\n" +#ifdef CONFIG_SMP + " mb\n" +#endif + ".subsection 2\n" + "3: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m), "=&r" (oldbit) + :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory"); + + return oldbit != 0; +} + /* * WARNING: non atomic version. */ @@ -376,7 +418,6 @@ static inline unsigned int hweight8(unsigned int w) #else #include <asm-generic/bitops/hweight.h> #endif -#include <asm-generic/bitops/lock.h> #endif /* __KERNEL__ */ |