From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/asm-frv/semaphore.h | 161 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100644 include/asm-frv/semaphore.h (limited to 'include/asm-frv/semaphore.h') diff --git a/include/asm-frv/semaphore.h b/include/asm-frv/semaphore.h new file mode 100644 index 00000000000..39354563080 --- /dev/null +++ b/include/asm-frv/semaphore.h @@ -0,0 +1,161 @@ +/* semaphore.h: semaphores for the FR-V + * + * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * 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. + */ +#ifndef _ASM_SEMAPHORE_H +#define _ASM_SEMAPHORE_H + +#define RW_LOCK_BIAS 0x01000000 + +#ifndef __ASSEMBLY__ + +#include +#include +#include +#include + +#define SEMAPHORE_DEBUG WAITQUEUE_DEBUG + +/* + * the semaphore definition + * - if counter is >0 then there are tokens available on the semaphore for down to collect + * - if counter is <=0 then there are no spare tokens, and anyone that wants one must wait + * - if wait_list is not empty, then there are processes waiting for the semaphore + */ +struct semaphore { + unsigned counter; + spinlock_t wait_lock; + struct list_head wait_list; +#if SEMAPHORE_DEBUG + unsigned __magic; +#endif +}; + +#if SEMAPHORE_DEBUG +# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic +#else +# define __SEM_DEBUG_INIT(name) +#endif + + +#define __SEMAPHORE_INITIALIZER(name,count) \ +{ count, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __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) + +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); +} + +extern void __down(struct semaphore *sem, unsigned long flags); +extern int __down_interruptible(struct semaphore *sem, unsigned long flags); +extern void __up(struct semaphore *sem); + +static inline void down(struct semaphore *sem) +{ + unsigned long flags; + +#if SEMAPHORE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + spin_lock_irqsave(&sem->wait_lock, flags); + if (likely(sem->counter > 0)) { + sem->counter--; + spin_unlock_irqrestore(&sem->wait_lock, flags); + } + else { + __down(sem, flags); + } +} + +static inline int down_interruptible(struct semaphore *sem) +{ + unsigned long flags; + int ret = 0; + +#if SEMAPHORE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + spin_lock_irqsave(&sem->wait_lock, flags); + if (likely(sem->counter > 0)) { + sem->counter--; + spin_unlock_irqrestore(&sem->wait_lock, flags); + } + else { + ret = __down_interruptible(sem, flags); + } + return ret; +} + +/* + * non-blockingly attempt to down() a semaphore. + * - returns zero if we acquired it + */ +static inline int down_trylock(struct semaphore *sem) +{ + unsigned long flags; + int success = 0; + +#if SEMAPHORE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + spin_lock_irqsave(&sem->wait_lock, flags); + if (sem->counter > 0) { + sem->counter--; + success = 1; + } + spin_unlock_irqrestore(&sem->wait_lock, flags); + return !success; +} + +static inline void up(struct semaphore *sem) +{ + unsigned long flags; + +#if SEMAPHORE_DEBUG + CHECK_MAGIC(sem->__magic); +#endif + + spin_lock_irqsave(&sem->wait_lock, flags); + if (!list_empty(&sem->wait_list)) + __up(sem); + else + sem->counter++; + spin_unlock_irqrestore(&sem->wait_lock, flags); +} + +static inline int sem_getcount(struct semaphore *sem) +{ + return sem->counter; +} + +#endif /* __ASSEMBLY__ */ + +#endif -- cgit v1.2.3