04fc8bbcf5
DECLARE_MUTEX_LOCKED was used for semaphores used as completions and we've got rid of them. Well, except for one in libusual that the maintainer explicitly wants to keep as semaphore. So convert that useage to an explicit sema_init and kill of DECLARE_MUTEX_LOCKED so that new code is reminded to use a completion. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: "Satyam Sharma" <satyam.sharma@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
145 lines
3.4 KiB
C
145 lines
3.4 KiB
C
#ifndef _ASM_M32R_SEMAPHORE_H
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#define _ASM_M32R_SEMAPHORE_H
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#include <linux/linkage.h>
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#ifdef __KERNEL__
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/*
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* SMP- and interrupt-safe semaphores..
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*
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* Copyright (C) 1996 Linus Torvalds
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* Copyright (C) 2004, 2006 Hirokazu Takata <takata at linux-m32r.org>
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*/
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#include <linux/wait.h>
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#include <linux/rwsem.h>
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#include <asm/assembler.h>
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#include <asm/system.h>
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#include <asm/atomic.h>
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struct semaphore {
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atomic_t count;
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int sleepers;
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wait_queue_head_t wait;
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};
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#define __SEMAPHORE_INITIALIZER(name, n) \
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{ \
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.count = ATOMIC_INIT(n), \
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.sleepers = 0, \
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.wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
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}
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#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
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struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
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#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
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static inline void sema_init (struct semaphore *sem, int val)
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{
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/*
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* *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val);
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*
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* i'd rather use the more flexible initialization above, but sadly
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* GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well.
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*/
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atomic_set(&sem->count, val);
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sem->sleepers = 0;
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init_waitqueue_head(&sem->wait);
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}
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static inline void init_MUTEX (struct semaphore *sem)
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{
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sema_init(sem, 1);
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}
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static inline void init_MUTEX_LOCKED (struct semaphore *sem)
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{
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sema_init(sem, 0);
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}
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asmlinkage void __down_failed(void /* special register calling convention */);
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asmlinkage int __down_failed_interruptible(void /* params in registers */);
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asmlinkage int __down_failed_trylock(void /* params in registers */);
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asmlinkage void __up_wakeup(void /* special register calling convention */);
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asmlinkage void __down(struct semaphore * sem);
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asmlinkage int __down_interruptible(struct semaphore * sem);
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asmlinkage int __down_trylock(struct semaphore * sem);
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asmlinkage void __up(struct semaphore * sem);
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/*
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* Atomically decrement the semaphore's count. If it goes negative,
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* block the calling thread in the TASK_UNINTERRUPTIBLE state.
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*/
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static inline void down(struct semaphore * sem)
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{
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might_sleep();
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if (unlikely(atomic_dec_return(&sem->count) < 0))
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__down(sem);
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}
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/*
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* Interruptible try to acquire a semaphore. If we obtained
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* it, return zero. If we were interrupted, returns -EINTR
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*/
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static inline int down_interruptible(struct semaphore * sem)
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{
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int result = 0;
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might_sleep();
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if (unlikely(atomic_dec_return(&sem->count) < 0))
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result = __down_interruptible(sem);
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return result;
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}
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/*
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* Non-blockingly attempt to down() a semaphore.
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* Returns zero if we acquired it
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*/
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static inline int down_trylock(struct semaphore * sem)
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{
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unsigned long flags;
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long count;
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int result = 0;
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local_irq_save(flags);
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__asm__ __volatile__ (
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"# down_trylock \n\t"
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DCACHE_CLEAR("%0", "r4", "%1")
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M32R_LOCK" %0, @%1; \n\t"
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"addi %0, #-1; \n\t"
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M32R_UNLOCK" %0, @%1; \n\t"
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: "=&r" (count)
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: "r" (&sem->count)
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: "memory"
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#ifdef CONFIG_CHIP_M32700_TS1
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, "r4"
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#endif /* CONFIG_CHIP_M32700_TS1 */
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);
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local_irq_restore(flags);
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if (unlikely(count < 0))
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result = __down_trylock(sem);
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return result;
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}
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/*
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* Note! This is subtle. We jump to wake people up only if
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* the semaphore was negative (== somebody was waiting on it).
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* The default case (no contention) will result in NO
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* jumps for both down() and up().
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*/
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static inline void up(struct semaphore * sem)
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{
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if (unlikely(atomic_inc_return(&sem->count) <= 0))
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__up(sem);
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}
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#endif /* __KERNEL__ */
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#endif /* _ASM_M32R_SEMAPHORE_H */
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