diff options
Diffstat (limited to 'include/asm-parisc/semaphore.h')
| -rw-r--r-- | include/asm-parisc/semaphore.h | 146 |
1 files changed, 1 insertions, 145 deletions
diff --git a/include/asm-parisc/semaphore.h b/include/asm-parisc/semaphore.h index a16271cdc748..d9b2034ed1d2 100644 --- a/include/asm-parisc/semaphore.h +++ b/include/asm-parisc/semaphore.h @@ -1,145 +1 @@ -/* 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) - -static 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. - */ - -static 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); -} - -static 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 - */ -static inline int down_trylock(struct semaphore * sem) -{ - unsigned long flags; - int 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). - */ -static inline void up(struct semaphore * sem) -{ - unsigned long 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> |