-/* SMP- and interrupt-safe semaphores.
- * PA-RISC version by Matthew Wilcox
- *
- * Linux/PA-RISC Project (http://www.parisc-linux.org/)
- * Copyright (C) 1996 Linus Torvalds
- * Copyright (C) 1999-2001 Matthew Wilcox < willy at debian d0T org >
- * Copyright (C) 2000 Grant Grundler < grundler a debian org >
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#ifndef _ASM_PARISC_SEMAPHORE_H
-#define _ASM_PARISC_SEMAPHORE_H
-
-#include <linux/spinlock.h>
-#include <linux/wait.h>
-#include <linux/rwsem.h>
-
-#include <asm/system.h>
-
-/*
- * The `count' is initialised to the number of people who are allowed to
- * take the lock. (Normally we want a mutex, so this is `1'). if
- * `count' is positive, the lock can be taken. if it's 0, no-one is
- * waiting on it. if it's -1, at least one task is waiting.
- */
-struct semaphore {
- spinlock_t sentry;
- int count;
- wait_queue_head_t wait;
-};
-
-#define __SEMAPHORE_INITIALIZER(name, n) \
-{ \
- .sentry = SPIN_LOCK_UNLOCKED, \
- .count = n, \
- .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
-}
-
-#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);
-}
-
-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);
-}
-
-static inline int sem_getcount(struct semaphore *sem)
-{
- return sem->count;
-}
-
-asmlinkage void __down(struct semaphore * sem);
-asmlinkage int __down_interruptible(struct semaphore * sem);
-asmlinkage void __up(struct semaphore * sem);
-
-/* Semaphores can be `tried' from irq context. So we have to disable
- * interrupts while we're messing with the semaphore. Sorry.
- */
-
-extern __inline__ void down(struct semaphore * sem)
-{
- might_sleep();
- spin_lock_irq(&sem->sentry);
- if (sem->count > 0) {
- sem->count--;
- } else {
- __down(sem);
- }
- spin_unlock_irq(&sem->sentry);
-}
-
-extern __inline__ int down_interruptible(struct semaphore * sem)
-{
- int ret = 0;
- might_sleep();
- spin_lock_irq(&sem->sentry);
- if (sem->count > 0) {
- sem->count--;
- } else {
- ret = __down_interruptible(sem);
- }
- spin_unlock_irq(&sem->sentry);
- return ret;
-}
-
-/*
- * down_trylock returns 0 on success, 1 if we failed to get the lock.
- * May not sleep, but must preserve irq state
- */
-extern __inline__ int down_trylock(struct semaphore * sem)
-{
- int flags, count;
-
- spin_lock_irqsave(&sem->sentry, flags);
- count = sem->count - 1;
- if (count >= 0)
- sem->count = count;
- spin_unlock_irqrestore(&sem->sentry, flags);
- return (count < 0);
-}
-
-/*
- * 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)
-{
- int flags;
- spin_lock_irqsave(&sem->sentry, flags);
- if (sem->count < 0) {
- __up(sem);
- } else {
- sem->count++;
- }
- spin_unlock_irqrestore(&sem->sentry, flags);
-}
-
-#endif /* _ASM_PARISC_SEMAPHORE_H */
+#include <linux/semaphore.h>
Code Review / linux-2.6.git / blobdiff