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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/asm-frv/semaphore.h
1 /* semaphore.h: semaphores for the FR-V
3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 #ifndef _ASM_SEMAPHORE_H
12 #define _ASM_SEMAPHORE_H
14 #define RW_LOCK_BIAS 0x01000000
18 #include <linux/linkage.h>
19 #include <linux/wait.h>
20 #include <linux/spinlock.h>
21 #include <linux/rwsem.h>
23 #define SEMAPHORE_DEBUG WAITQUEUE_DEBUG
26 * the semaphore definition
27 * - if counter is >0 then there are tokens available on the semaphore for down to collect
28 * - if counter is <=0 then there are no spare tokens, and anyone that wants one must wait
29 * - if wait_list is not empty, then there are processes waiting for the semaphore
34 struct list_head wait_list
;
41 # define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
43 # define __SEM_DEBUG_INIT(name)
47 #define __SEMAPHORE_INITIALIZER(name,count) \
48 { count, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __SEM_DEBUG_INIT(name) }
50 #define __MUTEX_INITIALIZER(name) \
51 __SEMAPHORE_INITIALIZER(name,1)
53 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
54 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
56 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
57 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
59 static inline void sema_init (struct semaphore
*sem
, int val
)
61 *sem
= (struct semaphore
) __SEMAPHORE_INITIALIZER(*sem
, val
);
64 static inline void init_MUTEX (struct semaphore
*sem
)
69 static inline void init_MUTEX_LOCKED (struct semaphore
*sem
)
74 extern void __down(struct semaphore
*sem
, unsigned long flags
);
75 extern int __down_interruptible(struct semaphore
*sem
, unsigned long flags
);
76 extern void __up(struct semaphore
*sem
);
78 static inline void down(struct semaphore
*sem
)
83 CHECK_MAGIC(sem
->__magic
);
86 spin_lock_irqsave(&sem
->wait_lock
, flags
);
87 if (likely(sem
->counter
> 0)) {
89 spin_unlock_irqrestore(&sem
->wait_lock
, flags
);
96 static inline int down_interruptible(struct semaphore
*sem
)
102 CHECK_MAGIC(sem
->__magic
);
105 spin_lock_irqsave(&sem
->wait_lock
, flags
);
106 if (likely(sem
->counter
> 0)) {
108 spin_unlock_irqrestore(&sem
->wait_lock
, flags
);
111 ret
= __down_interruptible(sem
, flags
);
117 * non-blockingly attempt to down() a semaphore.
118 * - returns zero if we acquired it
120 static inline int down_trylock(struct semaphore
*sem
)
126 CHECK_MAGIC(sem
->__magic
);
129 spin_lock_irqsave(&sem
->wait_lock
, flags
);
130 if (sem
->counter
> 0) {
134 spin_unlock_irqrestore(&sem
->wait_lock
, flags
);
138 static inline void up(struct semaphore
*sem
)
143 CHECK_MAGIC(sem
->__magic
);
146 spin_lock_irqsave(&sem
->wait_lock
, flags
);
147 if (!list_empty(&sem
->wait_list
))
151 spin_unlock_irqrestore(&sem
->wait_lock
, flags
);
154 static inline int sem_getcount(struct semaphore
*sem
)
159 #endif /* __ASSEMBLY__ */