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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 23:00:25 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-07 23:00:25 +0300 |
commit | 5bb47b9ff3d16d40f8d45380b373497a545fa280 (patch) | |
tree | e13dd34395473342dc75eff5cbaf5b1ea753631c /arch/blackfin/include/asm/mutex.h | |
parent | 2f2408a88cf8fa43febfd7fb5783e61b2937b0f9 (diff) | |
parent | 06af15e086e39a5a2a2413973a64af8e10122f28 (diff) | |
download | linux-5bb47b9ff3d16d40f8d45380b373497a545fa280.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (171 commits)
Blackfin arch: fix bug - BF527 0.2 silicon has different CPUID (DSPID) value
Blackfin arch: Enlarge flash partition for kenel for bf533/bf537 boards
Blackfin arch: fix bug: kernel crash when enable SDIO host driver
Blackfin arch: Print FP at level KERN_NOTICE
Blackfin arch: drop ad73311 test code
Blackfin arch: update board default configs
Blackfin arch: Set PB4 as the default irq for bf548 board v1.4+.
Blackfin arch: fix typo in early printk bit size processing
Blackfin arch: enable reprogram cclk and sclk for bf518f-ezbrd
Blackfin arch: add SDIO host driver platform data
Blackfin arch: fix bug - kernel stops at initial console
Blackfin arch: fix bug - kernel crash after config IP for ethernet port
Blackfin arch: add sdh support for bf518f-ezbrd
Blackfin arch: fix bug - kernel detects BF532 incorrectly
Blackfin arch: add () to avoid warnings from gcc
Blackfin arch: change HWTRACE Kconfig and set it on default
Blackfin arch: Clean oprofile build path for blackfin
Blackfin arch: remove hardware PM code, oprofile not use it
Blackfin arch: rewrite get_sclk()/get_vco()
Blackfin arch: cleanup and unify the ins functions
...
Diffstat (limited to 'arch/blackfin/include/asm/mutex.h')
-rw-r--r-- | arch/blackfin/include/asm/mutex.h | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/mutex.h b/arch/blackfin/include/asm/mutex.h index 458c1f7fbc18..5d399256bf06 100644 --- a/arch/blackfin/include/asm/mutex.h +++ b/arch/blackfin/include/asm/mutex.h @@ -6,4 +6,67 @@ * implementation. (see asm-generic/mutex-xchg.h for details) */ +#ifndef _ASM_MUTEX_H +#define _ASM_MUTEX_H + +#ifndef CONFIG_SMP #include <asm-generic/mutex-dec.h> +#else + +static inline void +__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + if (unlikely(atomic_dec_return(count) < 0)) + fail_fn(count); + else + smp_mb(); +} + +static inline int +__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + if (unlikely(atomic_dec_return(count) < 0)) + return fail_fn(count); + else { + smp_mb(); + return 0; + } +} + +static inline void +__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + smp_mb(); + if (unlikely(atomic_inc_return(count) <= 0)) + fail_fn(count); +} + +#define __mutex_slowpath_needs_to_unlock() 1 + +static inline int +__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + /* + * We have two variants here. The cmpxchg based one is the best one + * because it never induce a false contention state. It is included + * here because architectures using the inc/dec algorithms over the + * xchg ones are much more likely to support cmpxchg natively. + * + * If not we fall back to the spinlock based variant - that is + * just as efficient (and simpler) as a 'destructive' probing of + * the mutex state would be. + */ +#ifdef __HAVE_ARCH_CMPXCHG + if (likely(atomic_cmpxchg(count, 1, 0) == 1)) { + smp_mb(); + return 1; + } + return 0; +#else + return fail_fn(count); +#endif +} + +#endif + +#endif |