fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / include / asm-sh64 / semaphore.h
blobf027cc14b55bc96a59b6935d76cd5f9d8beee1b3
1 #ifndef __ASM_SH64_SEMAPHORE_H
2 #define __ASM_SH64_SEMAPHORE_H
4 /*
5 * This file is subject to the terms and conditions of the GNU General Public
6 * License. See the file "COPYING" in the main directory of this archive
7 * for more details.
9 * include/asm-sh64/semaphore.h
11 * Copyright (C) 2000, 2001 Paolo Alberelli
13 * SMP- and interrupt-safe semaphores.
15 * (C) Copyright 1996 Linus Torvalds
17 * SuperH verison by Niibe Yutaka
18 * (Currently no asm implementation but generic C code...)
22 #include <linux/linkage.h>
23 #include <linux/spinlock.h>
24 #include <linux/wait.h>
25 #include <linux/rwsem.h>
27 #include <asm/system.h>
28 #include <asm/atomic.h>
30 struct semaphore {
31 atomic_t count;
32 int sleepers;
33 wait_queue_head_t wait;
36 #define __SEMAPHORE_INITIALIZER(name, n) \
37 { \
38 .count = ATOMIC_INIT(n), \
39 .sleepers = 0, \
40 .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
43 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
44 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
46 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
48 static inline void sema_init (struct semaphore *sem, int val)
51 * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
53 * i'd rather use the more flexible initialization above, but sadly
54 * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well.
56 atomic_set(&sem->count, val);
57 sem->sleepers = 0;
58 init_waitqueue_head(&sem->wait);
61 static inline void init_MUTEX (struct semaphore *sem)
63 sema_init(sem, 1);
66 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
68 sema_init(sem, 0);
71 #if 0
72 asmlinkage void __down_failed(void /* special register calling convention */);
73 asmlinkage int __down_failed_interruptible(void /* params in registers */);
74 asmlinkage int __down_failed_trylock(void /* params in registers */);
75 asmlinkage void __up_wakeup(void /* special register calling convention */);
76 #endif
78 asmlinkage void __down(struct semaphore * sem);
79 asmlinkage int __down_interruptible(struct semaphore * sem);
80 asmlinkage int __down_trylock(struct semaphore * sem);
81 asmlinkage void __up(struct semaphore * sem);
83 extern spinlock_t semaphore_wake_lock;
85 static inline void down(struct semaphore * sem)
87 if (atomic_dec_return(&sem->count) < 0)
88 __down(sem);
91 static inline int down_interruptible(struct semaphore * sem)
93 int ret = 0;
95 if (atomic_dec_return(&sem->count) < 0)
96 ret = __down_interruptible(sem);
97 return ret;
100 static inline int down_trylock(struct semaphore * sem)
102 int ret = 0;
104 if (atomic_dec_return(&sem->count) < 0)
105 ret = __down_trylock(sem);
106 return ret;
110 * Note! This is subtle. We jump to wake people up only if
111 * the semaphore was negative (== somebody was waiting on it).
113 static inline void up(struct semaphore * sem)
115 if (atomic_inc_return(&sem->count) <= 0)
116 __up(sem);
119 #endif /* __ASM_SH64_SEMAPHORE_H */