diff options
author | Ralf Baechle <ralf@linux-mips.org> | 1999-10-09 00:00:47 +0000 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 1999-10-09 00:00:47 +0000 |
commit | d6434e1042f3b0a6dfe1b1f615af369486f9b1fa (patch) | |
tree | e2be02f33984c48ec019c654051d27964e42c441 /include/asm-sh/semaphore.h | |
parent | 609d1e803baf519487233b765eb487f9ec227a18 (diff) |
Merge with 2.3.19.
Diffstat (limited to 'include/asm-sh/semaphore.h')
-rw-r--r-- | include/asm-sh/semaphore.h | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/include/asm-sh/semaphore.h b/include/asm-sh/semaphore.h new file mode 100644 index 000000000..4164b7805 --- /dev/null +++ b/include/asm-sh/semaphore.h @@ -0,0 +1,134 @@ +#ifndef __ASM_SH_SEMAPHORE_H +#define __ASM_SH_SEMAPHORE_H + +#include <linux/linkage.h> + +/* + * SMP- and interrupt-safe semaphores. + * + * (C) Copyright 1996 Linus Torvalds + * + * SuperH verison by Niibe Yutaka + * + */ + +#include <linux/spinlock.h> + +#include <asm/system.h> +#include <asm/atomic.h> + +struct semaphore { + atomic_t count; + int waking; + wait_queue_head_t wait; +#if WAITQUEUE_DEBUG + long __magic; +#endif +}; + +#if WAITQUEUE_DEBUG +# define __SEM_DEBUG_INIT(name) \ + , (int)&(name).__magic +#else +# define __SEM_DEBUG_INIT(name) +#endif + +#define __SEMAPHORE_INITIALIZER(name,count) \ +{ ATOMIC_INIT(count), 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ + __SEM_DEBUG_INIT(name) } + +#define __MUTEX_INITIALIZER(name) \ + __SEMAPHORE_INITIALIZER(name,1) + +#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ + struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) + +#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) +#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) + +extern inline void sema_init (struct semaphore *sem, int val) +{ +/* + * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); + * + * i'd rather use the more flexible initialization above, but sadly + * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well. + */ + atomic_set(&sem->count, val); + sem->waking = 0; + init_waitqueue_head(&sem->wait); +#if WAITQUEUE_DEBUG + sem->__magic = (int)&sem->__magic; +#endif +} + +static inline void init_MUTEX (struct semaphore *sem) +{ + sema_init(sem, 1); +} + +static inline void init_MUTEX_LOCKED (struct semaphore *sem) +{ + sema_init(sem, 0); +} + +asmlinkage void __down_failed(void /* special register calling convention */); +asmlinkage int __down_failed_interruptible(void /* params in registers */); +asmlinkage int __down_failed_trylock(void /* params in registers */); +asmlinkage void __up_wakeup(void /* special register calling convention */); + +asmlinkage void __down(struct semaphore * sem); +asmlinkage int __down_interruptible(struct semaphore * sem); +asmlinkage int __down_trylock(struct semaphore * sem); +asmlinkage void __up(struct semaphore * sem); + +extern spinlock_t semaphore_wake_lock; + +extern __inline__ void down(struct semaphore * sem) +{ +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + if (atomic_dec_return(&sem->count) < 0) + __down(sem); +} + +extern __inline__ int down_interruptible(struct semaphore * sem) +{ + int ret = 0; +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + if (atomic_dec_return(&sem->count) < 0) + ret = __down_interruptible(sem); + return ret; +} + +extern __inline__ int down_trylock(struct semaphore * sem) +{ + int ret = 0; +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + if (atomic_dec_return(&sem->count) < 0) + ret = __down_trylock(sem); + return ret; +} + +/* + * Note! This is subtle. We jump to wake people up only if + * the semaphore was negative (== somebody was waiting on it). + */ +extern __inline__ void up(struct semaphore * sem) +{ +#if WAITQUEUE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + if (atomic_inc_return(&sem->count) <= 0) + __up(sem); +} + +#endif /* __ASM_SH_SEMAPHORE_H */ |