diff options
author | Matthew Wilcox <matthew@wil.cx> | 2008-03-08 05:55:58 +0300 |
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committer | Matthew Wilcox <willy@linux.intel.com> | 2008-04-17 18:42:34 +0400 |
commit | 64ac24e738823161693bf791f87adc802cf529ff (patch) | |
tree | 19c0b0cf314d4394ca580c05b86cdf874ce0a167 /include/asm-m68k/semaphore-helper.h | |
parent | e48b3deee475134585eed03e7afebe4bf9e0dba9 (diff) | |
download | linux-64ac24e738823161693bf791f87adc802cf529ff.tar.xz |
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/asm-m68k/semaphore-helper.h')
-rw-r--r-- | include/asm-m68k/semaphore-helper.h | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/include/asm-m68k/semaphore-helper.h b/include/asm-m68k/semaphore-helper.h deleted file mode 100644 index eef30ba0b499..000000000000 --- a/include/asm-m68k/semaphore-helper.h +++ /dev/null @@ -1,142 +0,0 @@ -#ifndef _M68K_SEMAPHORE_HELPER_H -#define _M68K_SEMAPHORE_HELPER_H - -/* - * SMP- and interrupt-safe semaphores helper functions. - * - * (C) Copyright 1996 Linus Torvalds - * - * m68k version by Andreas Schwab - */ - -#include <linux/errno.h> - -/* - * These two _must_ execute atomically wrt each other. - */ -static inline void wake_one_more(struct semaphore * sem) -{ - atomic_inc(&sem->waking); -} - -#ifndef CONFIG_RMW_INSNS -extern spinlock_t semaphore_wake_lock; -#endif - -static inline int waking_non_zero(struct semaphore *sem) -{ - int ret; -#ifndef CONFIG_RMW_INSNS - unsigned long flags; - - 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); -#else - int tmp1, tmp2; - - __asm__ __volatile__ - ("1: movel %1,%2\n" - " jle 2f\n" - " subql #1,%2\n" - " casl %1,%2,%3\n" - " jne 1b\n" - " moveq #1,%0\n" - "2:" - : "=d" (ret), "=d" (tmp1), "=d" (tmp2) - : "m" (sem->waking), "0" (0), "1" (sem->waking)); -#endif - - 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; -#ifndef CONFIG_RMW_INSNS - unsigned long flags; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - ret = 0; - 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); -#else - int tmp1, tmp2; - - __asm__ __volatile__ - ("1: movel %1,%2\n" - " jle 2f\n" - " subql #1,%2\n" - " casl %1,%2,%3\n" - " jne 1b\n" - " moveq #1,%0\n" - " jra %a4\n" - "2:" - : "=d" (ret), "=d" (tmp1), "=d" (tmp2) - : "m" (sem->waking), "i" (&&next), "0" (0), "1" (sem->waking)); - if (signal_pending(tsk)) { - atomic_inc(&sem->count); - ret = -EINTR; - } -next: -#endif - - 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; -#ifndef CONFIG_RMW_INSNS - unsigned long flags; - - spin_lock_irqsave(&semaphore_wake_lock, flags); - ret = 1; - if (atomic_read(&sem->waking) > 0) { - atomic_dec(&sem->waking); - ret = 0; - } else - atomic_inc(&sem->count); - spin_unlock_irqrestore(&semaphore_wake_lock, flags); -#else - int tmp1, tmp2; - - __asm__ __volatile__ - ("1: movel %1,%2\n" - " jle 2f\n" - " subql #1,%2\n" - " casl %1,%2,%3\n" - " jne 1b\n" - " moveq #0,%0\n" - "2:" - : "=d" (ret), "=d" (tmp1), "=d" (tmp2) - : "m" (sem->waking), "0" (1), "1" (sem->waking)); - if (ret) - atomic_inc(&sem->count); -#endif - return ret; -} - -#endif |