diff options
author | Matthew Wilcox <matthew@wil.cx> | 2008-03-07 21:55:58 -0500 |
---|---|---|
committer | Matthew Wilcox <willy@linux.intel.com> | 2008-04-17 10:42:34 -0400 |
commit | 64ac24e738823161693bf791f87adc802cf529ff (patch) | |
tree | 19c0b0cf314d4394ca580c05b86cdf874ce0a167 /include | |
parent | e48b3deee475134585eed03e7afebe4bf9e0dba9 (diff) |
Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
34 files changed, 100 insertions, 3760 deletions
diff --git a/include/asm-alpha/semaphore.h b/include/asm-alpha/semaphore.h index f1e9278a9fe..d9b2034ed1d 100644 --- a/include/asm-alpha/semaphore.h +++ b/include/asm-alpha/semaphore.h @@ -1,149 +1 @@ -#ifndef _ALPHA_SEMAPHORE_H -#define _ALPHA_SEMAPHORE_H - -/* - * SMP- and interrupt-safe semaphores.. - * - * (C) Copyright 1996 Linus Torvalds - * (C) Copyright 1996, 2000 Richard Henderson - */ - -#include <asm/current.h> -#include <asm/system.h> -#include <asm/atomic.h> -#include <linux/compiler.h> -#include <linux/wait.h> -#include <linux/rwsem.h> - -struct semaphore { - atomic_t count; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(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) -{ - /* - * Logically, - * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); - * except that gcc produces better initializing by parts yet. - */ - - atomic_set(&sem->count, val); - init_waitqueue_head(&sem->wait); -} - -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 *); -extern void __down_failed(struct semaphore *); -extern int down_interruptible(struct semaphore *); -extern int __down_failed_interruptible(struct semaphore *); -extern int down_trylock(struct semaphore *); -extern void up(struct semaphore *); -extern void __up_wakeup(struct semaphore *); - -/* - * Hidden out of line code is fun, but extremely messy. Rely on newer - * compilers to do a respectable job with this. The contention cases - * are handled out of line in arch/alpha/kernel/semaphore.c. - */ - -static inline void __down(struct semaphore *sem) -{ - long count; - might_sleep(); - count = atomic_dec_return(&sem->count); - if (unlikely(count < 0)) - __down_failed(sem); -} - -static inline int __down_interruptible(struct semaphore *sem) -{ - long count; - might_sleep(); - count = atomic_dec_return(&sem->count); - if (unlikely(count < 0)) - return __down_failed_interruptible(sem); - return 0; -} - -/* - * down_trylock returns 0 on success, 1 if we failed to get the lock. - */ - -static inline int __down_trylock(struct semaphore *sem) -{ - long ret; - - /* "Equivalent" C: - - do { - ret = ldl_l; - --ret; - if (ret < 0) - break; - ret = stl_c = ret; - } while (ret == 0); - */ - __asm__ __volatile__( - "1: ldl_l %0,%1\n" - " subl %0,1,%0\n" - " blt %0,2f\n" - " stl_c %0,%1\n" - " beq %0,3f\n" - " mb\n" - "2:\n" - ".subsection 2\n" - "3: br 1b\n" - ".previous" - : "=&r" (ret), "=m" (sem->count) - : "m" (sem->count)); - - return ret < 0; -} - -static inline void __up(struct semaphore *sem) -{ - if (unlikely(atomic_inc_return(&sem->count) <= 0)) - __up_wakeup(sem); -} - -#if !defined(CONFIG_DEBUG_SEMAPHORE) -extern inline void down(struct semaphore *sem) -{ - __down(sem); -} -extern inline int down_interruptible(struct semaphore *sem) -{ - return __down_interruptible(sem); -} -extern inline int down_trylock(struct semaphore *sem) -{ - return __down_trylock(sem); -} -extern inline void up(struct semaphore *sem) -{ - __up(sem); -} -#endif - -#endif +#include <linux/semaphore.h> diff --git a/include/asm-arm/semaphore-helper.h b/include/asm-arm/semaphore-helper.h deleted file mode 100644 index 1d7f1987edb..00000000000 --- a/include/asm-arm/semaphore-helper.h +++ /dev/null @@ -1,84 +0,0 @@ -#ifndef ASMARM_SEMAPHORE_HELPER_H -#define ASMARM_SEMAPHORE_HELPER_H - -/* - * These two _must_ execute atomically wrt each other. - */ -static inline void wake_one_more(struct semaphore * sem) -{ - unsigned long flags; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - if (atomic_read(&sem->count) <= 0) - sem->waking++; - spin_unlock_irqrestore(&semaphore_wake_lock, flags); -} - -static inline int waking_non_zero(struct semaphore *sem) -{ - unsigned long flags; - int ret = 0; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - if (sem->waking > 0) { - sem->waking--; - ret = 1; - } - spin_unlock_irqrestore(&semaphore_wake_lock, flags); - return ret; -} - -/* - * waking non zero interruptible - * 1 got the lock - * 0 go to sleep - * -EINTR interrupted - * - * We must undo the sem->count down_interruptible() increment while we are - * protected by the spinlock in order to make this atomic_inc() with the - * atomic_read() in wake_one_more(), otherwise we can race. -arca - */ -static inline int waking_non_zero_interruptible(struct semaphore *sem, - struct task_struct *tsk) -{ - unsigned long flags; - int ret = 0; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - if (sem->waking > 0) { - sem->waking--; - ret = 1; - } else if (signal_pending(tsk)) { - atomic_inc(&sem->count); - ret = -EINTR; - } - spin_unlock_irqrestore(&semaphore_wake_lock, flags); - return ret; -} - -/* - * waking_non_zero_try_lock: - * 1 failed to lock - * 0 got the lock - * - * We must undo the sem->count down_interruptible() increment while we are - * protected by the spinlock in order to make this atomic_inc() with the - * atomic_read() in wake_one_more(), otherwise we can race. -arca - */ -static inline int waking_non_zero_trylock(struct semaphore *sem) -{ - unsigned long flags; - int ret = 1; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - if (sem->waking <= 0) - atomic_inc(&sem->count); - else { - sem->waking--; - ret = 0; - } - spin_unlock_irqrestore(&semaphore_wake_lock, flags); - return ret; -} - -#endif diff --git a/include/asm-arm/semaphore.h b/include/asm-arm/semaphore.h index 1c8b441f89e..d9b2034ed1d 100644 --- a/include/asm-arm/semaphore.h +++ b/include/asm-arm/semaphore.h @@ -1,98 +1 @@ -/* - * linux/include/asm-arm/semaphore.h - */ -#ifndef __ASM_ARM_SEMAPHORE_H -#define __ASM_ARM_SEMAPHORE_H - -#include <linux/linkage.h> -#include <linux/spinlock.h> -#include <linux/wait.h> -#include <linux/rwsem.h> - -#include <asm/atomic.h> -#include <asm/locks.h> - -struct semaphore { - atomic_t count; - int sleepers; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INIT(name, cnt) \ -{ \ - .count = ATOMIC_INIT(cnt), \ - .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \ -} - -#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ - struct semaphore name = __SEMAPHORE_INIT(name,count) - -#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) - -static inline void sema_init(struct semaphore *sem, int val) -{ - atomic_set(&sem->count, val); - sem->sleepers = 0; - init_waitqueue_head(&sem->wait); -} - -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); -} - -/* - * special register calling convention - */ -asmlinkage void __down_failed(void); -asmlinkage int __down_interruptible_failed(void); -asmlinkage int __down_trylock_failed(void); -asmlinkage void __up_wakeup(void); - -extern void __down(struct semaphore * sem); -extern int __down_interruptible(struct semaphore * sem); -extern int __down_trylock(struct semaphore * sem); -extern void __up(struct semaphore * sem); - -/* - * This is ugly, but we want the default case to fall through. - * "__down" is the actual routine that waits... - */ -static inline void down(struct semaphore * sem) -{ - might_sleep(); - __down_op(sem, __down_failed); -} - -/* - * This is ugly, but we want the default case to fall through. - * "__down_interruptible" is the actual routine that waits... - */ -static inline int down_interruptible (struct semaphore * sem) -{ - might_sleep(); - return __down_op_ret(sem, __down_interruptible_failed); -} - -static inline int down_trylock(struct semaphore *sem) -{ - return __down_op_ret(sem, __down_trylock_failed); -} - -/* - * Note! This is subtle. We jump to wake people up only if - * the semaphore was negative (== somebody was waiting on it). - * The default case (no contention) will result in NO - * jumps for both down() and up(). - */ -static inline void up(struct semaphore * sem) -{ - __up_op(sem, __up_wakeup); -} - -#endif +#include <linux/semaphore.h> diff --git a/include/asm-avr32/semaphore.h b/include/asm-avr32/semaphore.h index feaf1d45338..d9b2034ed1d 100644 --- a/include/asm-avr32/semaphore.h +++ b/include/asm-avr32/semaphore.h @@ -1,108 +1 @@ -/* - * SMP- and interrupt-safe semaphores. - * - * Copyright (C) 2006 Atmel Corporation - * - * Based on include/asm-i386/semaphore.h - * Copyright (C) 1996 Linus Torvalds - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ -#ifndef __ASM_AVR32_SEMAPHORE_H -#define __ASM_AVR32_SEMAPHORE_H - -#include <linux/linkage.h> - -#include <asm/system.h> -#include <asm/atomic.h> -#include <linux/wait.h> -#include <linux/rwsem.h> - -struct semaphore { - atomic_t count; - int sleepers; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(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) -{ - atomic_set(&sem->count, val); - sem->sleepers = 0; - init_waitqueue_head(&sem->wait); -} - -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); -} - -void __down(struct semaphore * sem); -int __down_interruptible(struct semaphore * sem); -void __up(struct semaphore * sem); - -/* - * This is ugly, but we want the default case to fall through. - * "__down_failed" is a special asm handler that calls the C - * routine that actually waits. See arch/i386/kernel/semaphore.c - */ -static inline void down(struct semaphore * sem) -{ - might_sleep(); - if (unlikely(atomic_dec_return (&sem->count) < 0)) - __down (sem); -} - -/* - * Interruptible try to acquire a semaphore. If we obtained - * it, return zero. If we were interrupted, returns -EINTR - */ -static inline int down_interruptible(struct semaphore * sem) -{ - int ret = 0; - - might_sleep(); - if (unlikely(atomic_dec_return (&sem->count) < 0)) - ret = __down_interruptible (sem); - return ret; -} - -/* - * Non-blockingly attempt to down() a semaphore. - * Returns zero if we acquired it - */ -static inline int down_trylock(struct semaphore * sem) -{ - return atomic_dec_if_positive(&sem->count) < 0; -} - -/* - * Note! This is subtle. We jump to wake people up only if - * the semaphore was negative (== somebody was waiting on it). - * The default case (no contention) will result in NO - * jumps for both down() and up(). - */ -static inline void up(struct semaphore * sem) -{ - if (unlikely(atomic_inc_return (&sem->count) <= 0)) - __up (sem); -} - -#endif /*__ASM_AVR32_SEMAPHORE_H */ +#include <linux/semaphore.h> diff --git a/include/asm-blackfin/semaphore-helper.h b/include/asm-blackfin/semaphore-helper.h deleted file mode 100644 index 9082b0dc3eb..00000000000 --- a/include/asm-blackfin/semaphore-helper.h +++ /dev/null @@ -1,82 +0,0 @@ -/* Based on M68K version, Lineo Inc. May 2001 */ - -#ifndef _BFIN_SEMAPHORE_HELPER_H -#define _BFIN_SEMAPHORE_HELPER_H - -/* - * SMP- and interrupt-safe semaphores helper functions. - * - * (C) Copyright 1996 Linus Torvalds - * - */ - -#include <asm/errno.h> - -/* - * These two _must_ execute atomically wrt each other. - */ -static inline void wake_one_more(struct semaphore *sem) -{ - atomic_inc(&sem->waking); -} - -static inline int waking_non_zero(struct semaphore *sem) -{ - int ret; - unsigned long flags = 0; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - ret = 0; - if (atomic_read(&sem->waking) > 0) { - atomic_dec(&sem->waking); - ret = 1; - } - spin_unlock_irqrestore(&semaphore_wake_lock, flags); - return ret; -} - -/* - * waking_non_zero_interruptible: - * 1 got the lock - * 0 go to sleep - * -EINTR interrupted - */ -static inline int waking_non_zero_interruptible(struct semaphore *sem, - struct task_struct *tsk) -{ - int ret = 0; - unsigned long flags = 0; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - if (atomic_read(&sem->waking) > 0) { - atomic_dec(&sem->waking); - ret = 1; - } else if (signal_pending(tsk)) { - atomic_inc(&sem->count); - ret = -EINTR; - } - spin_unlock_irqrestore(&semaphore_wake_lock, flags); - return ret; -} - -/* - * waking_non_zero_trylock: - * 1 failed to lock - * 0 got the lock - */ -static inline int waking_non_zero_trylock(struct semaphore *sem) -{ - int ret = 1; - unsigned long flags = 0; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - if (atomic_read(&sem->waking) > 0) { - atomic_dec(&sem->waking); - ret = 0; - } else - atomic_inc(&sem->count); - spin_unlock_irqrestore(&semaphore_wake_lock, flags); - return ret; -} - -#endif /* _BFIN_SEMAPHORE_HELPER_H */ diff --git a/include/asm-blackfin/semaphore.h b/include/asm-blackfin/semaphore.h index 533f90fb2e4..d9b2034ed1d 100644 --- a/include/asm-blackfin/semaphore.h +++ b/include/asm-blackfin/semaphore.h @@ -1,105 +1 @@ -#ifndef _BFIN_SEMAPHORE_H -#define _BFIN_SEMAPHORE_H - -#ifndef __ASSEMBLY__ - -#include <linux/linkage.h> -#include <linux/wait.h> -#include <linux/spinlock.h> -#include <linux/rwsem.h> -#include <asm/atomic.h> - -/* - * Interrupt-safe semaphores.. - * - * (C) Copyright 1996 Linus Torvalds - * - * BFIN version by akbar hussain Lineo Inc April 2001 - * - */ - -struct semaphore { - atomic_t count; - int sleepers; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(n), \ - .sleepers = 0, \ - .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); -} - -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; - -/* - * This is ugly, but we want the default case to fall through. - * "down_failed" is a special asm handler that calls the C - * routine that actually waits. - */ -static inline void down(struct semaphore *sem) -{ - might_sleep(); - if (atomic_dec_return(&sem->count) < 0) - __down(sem); -} - -static inline int down_interruptible(struct semaphore *sem) -{ - int ret = 0; - - might_sleep(); - if (atomic_dec_return(&sem->count) < 0) - ret = __down_interruptible(sem); - return (ret); -} - -static inline int down_trylock(struct semaphore *sem) -{ - int ret = 0; - - 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). - * The default case (no contention) will result in NO - * jumps for both down() and up(). - */ -static inline void up(struct semaphore *sem) -{ - if (atomic_inc_return(&sem->count) <= 0) - __up(sem); -} - -#endif /* __ASSEMBLY__ */ -#endif /* _BFIN_SEMAPHORE_H */ +#include <linux/semaphore.h> diff --git a/include/asm-cris/semaphore-helper.h b/include/asm-cris/semaphore-helper.h deleted file mode 100644 index 27bfeca1b98..00000000000 --- a/include/asm-cris/semaphore-helper.h +++ /dev/null @@ -1,78 +0,0 @@ -/* $Id: semaphore-helper.h,v 1.3 2001/03/26 15:00:33 orjanf Exp $ - * - * SMP- and interrupt-safe semaphores helper functions. Generic versions, no - * optimizations whatsoever... - * - */ - -#ifndef _ASM_SEMAPHORE_HELPER_H -#define _ASM_SEMAPHORE_HELPER_H - -#include <asm/atomic.h> -#include <linux/errno.h> - -#define read(a) ((a)->counter) -#define inc(a) (((a)->counter)++) -#define dec(a) (((a)->counter)--) - -#define count_inc(a) ((*(a))++) - -/* - * These two _must_ execute atomically wrt each other. - */ -static inline void wake_one_more(struct semaphore * sem) -{ - atomic_inc(&sem->waking); -} - -static inline int waking_non_zero(struct semaphore *sem) -{ - unsigned long flags; - int ret = 0; - - local_irq_save(flags); - if (read(&sem->waking) > 0) { - dec(&sem->waking); - ret = 1; - } - local_irq_restore(flags); - return ret; -} - -static inline int waking_non_zero_interruptible(struct semaphore *sem, - struct task_struct *tsk) -{ - int ret = 0; - unsigned long flags; - - local_irq_save(flags); - if (read(&sem->waking) > 0) { - dec(&sem->waking); - ret = 1; - } else if (signal_pending(tsk)) { - inc(&sem->count); - ret = -EINTR; - } - local_irq_restore(flags); - return ret; -} - -static inline int waking_non_zero_trylock(struct semaphore *sem) -{ - int ret = 1; - unsigned long flags; - - local_irq_save(flags); - if (read(&sem->waking) <= 0) - inc(&sem->count); - else { - dec(&sem->waking); - ret = 0; - } - local_irq_restore(flags); - return ret; -} - -#endif /* _ASM_SEMAPHORE_HELPER_H */ - - diff --git a/include/asm-cris/semaphore.h b/include/asm-cris/semaphore.h index 31a4ac44819..d9b2034ed1d 100644 --- a/include/asm-cris/semaphore.h +++ b/include/asm-cris/semaphore.h @@ -1,133 +1 @@ -/* $Id: semaphore.h,v 1.3 2001/05/08 13:54:09 bjornw Exp $ */ - -/* On the i386 these are coded in asm, perhaps we should as well. Later.. */ - -#ifndef _CRIS_SEMAPHORE_H -#define _CRIS_SEMAPHORE_H - -#define RW_LOCK_BIAS 0x01000000 - -#include <linux/wait.h> -#include <linux/spinlock.h> -#include <linux/rwsem.h> - -#include <asm/system.h> -#include <asm/atomic.h> - -/* - * CRIS semaphores, implemented in C-only so far. - */ - -struct semaphore { - atomic_t count; - atomic_t waking; - wait_queue_head_t wait; -}; - -#define __SEMAPHORE_INITIALIZER(name, n) \ -{ \ - .count = ATOMIC_INIT(n), \ - .waking = ATOMIC_INIT(0), \ - .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); -} - -extern void __down(struct semaphore * sem); -extern int __down_interruptible(struct semaphore * sem); -extern int __down_trylock(struct semaphore * sem); -extern void __up(struct semaphore * sem); - -/* notice - we probably can do cli/sti here instead of saving */ - -static inline void down(struct semaphore * sem) -{ - unsigned long flags; - int failed; - - might_sleep(); - - /* atomically decrement the semaphores count, and if its negative, we wait */ - cris_atomic_save(sem, flags); - failed = --(sem->count.counter) < 0; - cris_atomic_restore(sem, flags); - if(failed) { - __down(sem); - } -} - -/* - * This version waits in interruptible state so that the waiting - * process can be killed. The down_interruptible routine - * returns negative for signalled and zero for semaphore acquired. - */ - -static inline int down_interruptible(struct semaphore * sem) -{ - unsigned long flags; - int failed; - - might_sleep(); - - /* atomically decrement the semaphores count, and if its negative, we wait */ - cris_atomic_save(sem, flags); - failed = --(sem->count.counter) < 0; - cris_atomic_restore(sem, flags); - if(failed) - failed = __down_interruptible(sem); - return(failed); -} - -static inline int down_trylock(struct semaphore * sem) -{ - unsigned long flags; - int failed; - - cris_atomic_save(sem, flags); - failed = --(sem->count.counter) < 0; - cris_atomic_restore(sem, flags); - if(failed) - failed = __down_trylock(sem); - return(failed); - -} - -/* - * Note! This is subtle. We jump to wake people up only if - * the semaphore was negative (== somebody was waiting on it). - * The default case (no contention) will result in NO - * jumps for both down() and up(). - */ -static inline void up(struct semaphore * sem) -{ - unsigned long flags; - int wakeup; - - /* atomically increment the semaphores count, and if it was negative, we wake people */ - cris_atomic_save(sem, flags); - wakeup = ++(sem->count.counter) <= 0; - cris_atomic_restore(sem, flags); - if(wakeup) { - __up(sem); - } -} - -#endif +#include <linux/semaphore.h> diff --git a/include/asm-frv/semaphore.h b/include/asm-frv/semaphore.h index d7aaa1911a1..d9b2034ed1d 100644 --- a/include/asm-frv/semaphore.h +++ b/include/asm-frv/semaphore.h @@ -1,155 +1 @@ -/* 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 <linux/linkage.h> -#include <linux/wait.h> -#include <linux/spinlock.h> -#include <linux/rwsem.h> - -/* - * 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 wa |