diff options
author | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2008-12-29 16:47:18 +1100 |
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committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2008-12-29 16:47:18 +1100 |
commit | 0a8c5395f90f06d128247844b2515c8bf3f2826b (patch) | |
tree | d95382dcdfa303b99d480c01763d6cb6767fdaca /arch/powerpc/include/asm/mutex.h | |
parent | 25051158bbed127e8672b43396c71c5eb610e5f1 (diff) | |
parent | 3c92ec8ae91ecf59d88c798301833d7cf83f2179 (diff) |
[XFS] Fix merge failures
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:
fs/xfs/linux-2.6/xfs_cred.h
fs/xfs/linux-2.6/xfs_globals.h
fs/xfs/linux-2.6/xfs_ioctl.c
fs/xfs/xfs_vnodeops.h
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Diffstat (limited to 'arch/powerpc/include/asm/mutex.h')
-rw-r--r-- | arch/powerpc/include/asm/mutex.h | 135 |
1 files changed, 130 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/mutex.h b/arch/powerpc/include/asm/mutex.h index 458c1f7fbc1..dabc01c727b 100644 --- a/arch/powerpc/include/asm/mutex.h +++ b/arch/powerpc/include/asm/mutex.h @@ -1,9 +1,134 @@ /* - * Pull in the generic implementation for the mutex fastpath. + * Optimised mutex implementation of include/asm-generic/mutex-dec.h algorithm + */ +#ifndef _ASM_POWERPC_MUTEX_H +#define _ASM_POWERPC_MUTEX_H + +static inline int __mutex_cmpxchg_lock(atomic_t *v, int old, int new) +{ + int t; + + __asm__ __volatile__ ( +"1: lwarx %0,0,%1 # mutex trylock\n\ + cmpw 0,%0,%2\n\ + bne- 2f\n" + PPC405_ERR77(0,%1) +" stwcx. %3,0,%1\n\ + bne- 1b" + ISYNC_ON_SMP + "\n\ +2:" + : "=&r" (t) + : "r" (&v->counter), "r" (old), "r" (new) + : "cc", "memory"); + + return t; +} + +static inline int __mutex_dec_return_lock(atomic_t *v) +{ + int t; + + __asm__ __volatile__( +"1: lwarx %0,0,%1 # mutex lock\n\ + addic %0,%0,-1\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1\n\ + bne- 1b" + ISYNC_ON_SMP + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory"); + + return t; +} + +static inline int __mutex_inc_return_unlock(atomic_t *v) +{ + int t; + + __asm__ __volatile__( + LWSYNC_ON_SMP +"1: lwarx %0,0,%1 # mutex unlock\n\ + addic %0,%0,1\n" + PPC405_ERR77(0,%1) +" stwcx. %0,0,%1 \n\ + bne- 1b" + : "=&r" (t) + : "r" (&v->counter) + : "cc", "memory"); + + return t; +} + +/** + * __mutex_fastpath_lock - try to take the lock by moving the count + * from 1 to a 0 value + * @count: pointer of type atomic_t + * @fail_fn: function to call if the original value was not 1 + * + * Change the count from 1 to a value lower than 1, and call <fail_fn> if + * it wasn't 1 originally. This function MUST leave the value lower than + * 1 even when the "1" assertion wasn't true. + */ +static inline void +__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + if (unlikely(__mutex_dec_return_lock(count) < 0)) + fail_fn(count); +} + +/** + * __mutex_fastpath_lock_retval - try to take the lock by moving the count + * from 1 to a 0 value + * @count: pointer of type atomic_t + * @fail_fn: function to call if the original value was not 1 + * + * Change the count from 1 to a value lower than 1, and call <fail_fn> if + * it wasn't 1 originally. This function returns 0 if the fastpath succeeds, + * or anything the slow path function returns. + */ +static inline int +__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + if (unlikely(__mutex_dec_return_lock(count) < 0)) + return fail_fn(count); + return 0; +} + +/** + * __mutex_fastpath_unlock - try to promote the count from 0 to 1 + * @count: pointer of type atomic_t + * @fail_fn: function to call if the original value was not 0 + * + * Try to promote the count from 0 to 1. If it wasn't 0, call <fail_fn>. + * In the failure case, this function is allowed to either set the value to + * 1, or to set it to a value lower than 1. + */ +static inline void +__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *)) +{ + if (unlikely(__mutex_inc_return_unlock(count) <= 0)) + fail_fn(count); +} + +#define __mutex_slowpath_needs_to_unlock() 1 + +/** + * __mutex_fastpath_trylock - try to acquire the mutex, without waiting + * + * @count: pointer of type atomic_t + * @fail_fn: fallback function * - * TODO: implement optimized primitives instead, or leave the generic - * implementation in place, or pick the atomic_xchg() based generic - * implementation. (see asm-generic/mutex-xchg.h for details) + * Change the count from 1 to 0, and return 1 (success), or if the count + * was not 1, then return 0 (failure). */ +static inline int +__mutex_fastpath_trylock(atomic_t *count, int (*fail_fn)(atomic_t *)) +{ + if (likely(__mutex_cmpxchg_lock(count, 1, 0) == 1)) + return 1; + return 0; +} -#include <asm-generic/mutex-dec.h> +#endif |