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-rw-r--r--include/asm-mn10300/semaphore.h170
1 files changed, 1 insertions, 169 deletions
diff --git a/include/asm-mn10300/semaphore.h b/include/asm-mn10300/semaphore.h
index 5a9e1ad0b253..d9b2034ed1d2 100644
--- a/include/asm-mn10300/semaphore.h
+++ b/include/asm-mn10300/semaphore.h
@@ -1,169 +1 @@
1/* MN10300 Semaphores #include <linux/semaphore.h>
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11#ifndef _ASM_SEMAPHORE_H
12#define _ASM_SEMAPHORE_H
13
14#ifndef __ASSEMBLY__
15
16#include <linux/linkage.h>
17#include <linux/wait.h>
18#include <linux/spinlock.h>
19#include <linux/rwsem.h>
20
21#define SEMAPHORE_DEBUG 0
22
23/*
24 * the semaphore definition
25 * - if count is >0 then there are tokens available on the semaphore for down
26 * to collect
27 * - if count is <=0 then there are no spare tokens, and anyone that wants one
28 * must wait
29 * - if wait_list is not empty, then there are processes waiting for the
30 * semaphore
31 */
32struct semaphore {
33 atomic_t count; /* it's not really atomic, it's
34 * just that certain modules
35 * expect to be able to access
36 * it directly */
37 spinlock_t wait_lock;
38 struct list_head wait_list;
39#if SEMAPHORE_DEBUG
40 unsigned __magic;
41#endif
42};
43
44#if SEMAPHORE_DEBUG
45# define __SEM_DEBUG_INIT(name) , (long)&(name).__magic
46#else
47# define __SEM_DEBUG_INIT(name)
48#endif
49
50
51#define __SEMAPHORE_INITIALIZER(name, init_count) \
52{ \
53 .count = ATOMIC_INIT(init_count), \
54 .wait_lock = __SPIN_LOCK_UNLOCKED((name).wait_lock), \
55 .wait_list = LIST_HEAD_INIT((name).wait_list) \
56 __SEM_DEBUG_INIT(name) \
57}
58
59#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
60 struct semaphore name = __SEMAPHORE_INITIALIZER(name, count)
61
62#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name, 1)
63#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name, 0)
64
65static inline void sema_init(struct semaphore *sem, int val)
66{
67 *sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
68}
69
70static inline void init_MUTEX(struct semaphore *sem)
71{
72 sema_init(sem, 1);
73}
74
75static inline void init_MUTEX_LOCKED(struct semaphore *sem)
76{
77 sema_init(sem, 0);
78}
79
80extern void __down(struct semaphore *sem, unsigned long flags);
81extern int __down_interruptible(struct semaphore *sem, unsigned long flags);
82extern void __up(struct semaphore *sem);
83
84static inline void down(struct semaphore *sem)
85{
86 unsigned long flags;
87 int count;
88
89#if SEMAPHORE_DEBUG
90 CHECK_MAGIC(sem->__magic);
91#endif
92
93 spin_lock_irqsave(&sem->wait_lock, flags);
94 count = atomic_read(&sem->count);
95 if (likely(count > 0)) {
96 atomic_set(&sem->count, count - 1);
97 spin_unlock_irqrestore(&sem->wait_lock, flags);
98 } else {
99 __down(sem, flags);
100 }
101}
102
103static inline int down_interruptible(struct semaphore *sem)
104{
105 unsigned long flags;
106 int count, ret = 0;
107
108#if SEMAPHORE_DEBUG
109 CHECK_MAGIC(sem->__magic);
110#endif
111
112 spin_lock_irqsave(&sem->wait_lock, flags);
113 count = atomic_read(&sem->count);
114 if (likely(count > 0)) {
115 atomic_set(&sem->count, count - 1);
116 spin_unlock_irqrestore(&sem->wait_lock, flags);
117 } else {
118 ret = __down_interruptible(sem, flags);
119 }
120 return ret;
121}
122
123/*
124 * non-blockingly attempt to down() a semaphore.
125 * - returns zero if we acquired it
126 */
127static inline int down_trylock(struct semaphore *sem)
128{
129 unsigned long flags;
130 int count, success = 0;
131
132#if SEMAPHORE_DEBUG
133 CHECK_MAGIC(sem->__magic);
134#endif
135
136 spin_lock_irqsave(&sem->wait_lock, flags);
137 count = atomic_read(&sem->count);
138 if (likely(count > 0)) {
139 atomic_set(&sem->count, count - 1);
140 success = 1;
141 }
142 spin_unlock_irqrestore(&sem->wait_lock, flags);
143 return !success;
144}
145
146static inline void up(struct semaphore *sem)
147{
148 unsigned long flags;
149
150#if SEMAPHORE_DEBUG
151 CHECK_MAGIC(sem->__magic);
152#endif
153
154 spin_lock_irqsave(&sem->wait_lock, flags);
155 if (!list_empty(&sem->wait_list))
156 __up(sem);
157 else
158 atomic_set(&sem->count, atomic_read(&sem->count) + 1);
159 spin_unlock_irqrestore(&sem->wait_lock, flags);
160}
161
162static inline int sem_getcount(struct semaphore *sem)
163{
164 return atomic_read(&sem->count);
165}
166
167#endif /* __ASSEMBLY__ */
168
169#endif
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