diff options
| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-04-19 12:17:34 -0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-04-19 12:17:34 -0400 |
| commit | cf816ecb533ab96b883dfdc0db174598b5b5c4d2 (patch) | |
| tree | 1b7705db288ae2917105e624b01fdf81e0882bf1 /include/asm-mips/semaphore.h | |
| parent | adf6d34e460387ee3e8f1e1875d52bff51212c7d (diff) | |
| parent | 15f7d677ccff6f0f5de8a1ee43a792567e9f9de9 (diff) | |
Merge branch 'merge-fixes' into devel
Diffstat (limited to 'include/asm-mips/semaphore.h')
| -rw-r--r-- | include/asm-mips/semaphore.h | 109 |
1 files changed, 1 insertions, 108 deletions
diff --git a/include/asm-mips/semaphore.h b/include/asm-mips/semaphore.h index fdf8042b784b..d9b2034ed1d2 100644 --- a/include/asm-mips/semaphore.h +++ b/include/asm-mips/semaphore.h | |||
| @@ -1,108 +1 @@ | |||
| 1 | /* | #include <linux/semaphore.h> | |
| 2 | * This file is subject to the terms and conditions of the GNU General Public | ||
| 3 | * License. See the file "COPYING" in the main directory of this archive | ||
| 4 | * for more details. | ||
| 5 | * | ||
| 6 | * Copyright (C) 1996 Linus Torvalds | ||
| 7 | * Copyright (C) 1998, 99, 2000, 01, 04 Ralf Baechle | ||
| 8 | * Copyright (C) 1999, 2000, 01 Silicon Graphics, Inc. | ||
| 9 | * Copyright (C) 2000, 01 MIPS Technologies, Inc. | ||
| 10 | * | ||
| 11 | * In all honesty, little of the old MIPS code left - the PPC64 variant was | ||
| 12 | * just looking nice and portable so I ripped it. Credits to whoever wrote | ||
| 13 | * it. | ||
| 14 | */ | ||
| 15 | #ifndef __ASM_SEMAPHORE_H | ||
| 16 | #define __ASM_SEMAPHORE_H | ||
| 17 | |||
| 18 | /* | ||
| 19 | * Remove spinlock-based RW semaphores; RW semaphore definitions are | ||
| 20 | * now in rwsem.h and we use the generic lib/rwsem.c implementation. | ||
| 21 | * Rework semaphores to use atomic_dec_if_positive. | ||
| 22 | * -- Paul Mackerras (paulus@samba.org) | ||
| 23 | */ | ||
| 24 | |||
| 25 | #ifdef __KERNEL__ | ||
| 26 | |||
| 27 | #include <asm/atomic.h> | ||
| 28 | #include <asm/system.h> | ||
| 29 | #include <linux/wait.h> | ||
| 30 | #include <linux/rwsem.h> | ||
| 31 | |||
| 32 | struct semaphore { | ||
| 33 | /* | ||
| 34 | * Note that any negative value of count is equivalent to 0, | ||
| 35 | * but additionally indicates that some process(es) might be | ||
| 36 | * sleeping on `wait'. | ||
| 37 | */ | ||
| 38 | atomic_t count; | ||
| 39 | wait_queue_head_t wait; | ||
| 40 | }; | ||
| 41 | |||
| 42 | #define __SEMAPHORE_INITIALIZER(name, n) \ | ||
| 43 | { \ | ||
| 44 | .count = ATOMIC_INIT(n), \ | ||
| 45 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | ||
| 46 | } | ||
| 47 | |||
| 48 | #define __DECLARE_SEMAPHORE_GENERIC(name, count) \ | ||
| 49 | struct semaphore name = __SEMAPHORE_INITIALIZER(name, count) | ||
| 50 | |||
| 51 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1) | ||
| 52 | |||
| 53 | static inline void sema_init(struct semaphore *sem, int val) | ||
| 54 | { | ||
| 55 | atomic_set(&sem->count, val); | ||
| 56 | init_waitqueue_head(&sem->wait); | ||
| 57 | } | ||
| 58 | |||
| 59 | static inline void init_MUTEX(struct semaphore *sem) | ||
| 60 | { | ||
| 61 | sema_init(sem, 1); | ||
| 62 | } | ||
| 63 | |||
| 64 | static inline void init_MUTEX_LOCKED(struct semaphore *sem) | ||
| 65 | { | ||
| 66 | sema_init(sem, 0); | ||
| 67 | } | ||
| 68 | |||
| 69 | extern void __down(struct semaphore * sem); | ||
| 70 | extern int __down_interruptible(struct semaphore * sem); | ||
| 71 | extern void __up(struct semaphore * sem); | ||
| 72 | |||
| 73 | static inline void down(struct semaphore * sem) | ||
| 74 | { | ||
| 75 | might_sleep(); | ||
| 76 | |||
| 77 | /* | ||
| 78 | * Try to get the semaphore, take the slow path if we fail. | ||
| 79 | */ | ||
| 80 | if (unlikely(atomic_dec_return(&sem->count) < 0)) | ||
| 81 | __down(sem); | ||
| 82 | } | ||
| 83 | |||
| 84 | static inline int down_interruptible(struct semaphore * sem) | ||
| 85 | { | ||
| 86 | int ret = 0; | ||
| 87 | |||
| 88 | might_sleep(); | ||
| 89 | |||
| 90 | if (unlikely(atomic_dec_return(&sem->count) < 0)) | ||
| 91 | ret = __down_interruptible(sem); | ||
| 92 | return ret; | ||
| 93 | } | ||
| 94 | |||
| 95 | static inline int down_trylock(struct semaphore * sem) | ||
| 96 | { | ||
| 97 | return atomic_dec_if_positive(&sem->count) < 0; | ||
| 98 | } | ||
| 99 | |||
| 100 | static inline void up(struct semaphore * sem) | ||
| 101 | { | ||
| 102 | if (unlikely(atomic_inc_return(&sem->count) <= 0)) | ||
| 103 | __up(sem); | ||
| 104 | } | ||
| 105 | |||
| 106 | #endif /* __KERNEL__ */ | ||
| 107 | |||
| 108 | #endif /* __ASM_SEMAPHORE_H */ | ||
