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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-m68knommu/semaphore.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-m68knommu/semaphore.h')
-rw-r--r--include/asm-m68knommu/semaphore.h157
1 files changed, 157 insertions, 0 deletions
diff --git a/include/asm-m68knommu/semaphore.h b/include/asm-m68knommu/semaphore.h
new file mode 100644
index 000000000000..febe85add509
--- /dev/null
+++ b/include/asm-m68knommu/semaphore.h
@@ -0,0 +1,157 @@
1#ifndef _M68K_SEMAPHORE_H
2#define _M68K_SEMAPHORE_H
3
4#define RW_LOCK_BIAS 0x01000000
5
6#ifndef __ASSEMBLY__
7
8#include <linux/linkage.h>
9#include <linux/wait.h>
10#include <linux/spinlock.h>
11#include <linux/rwsem.h>
12
13#include <asm/system.h>
14#include <asm/atomic.h>
15
16/*
17 * Interrupt-safe semaphores..
18 *
19 * (C) Copyright 1996 Linus Torvalds
20 *
21 * m68k version by Andreas Schwab
22 */
23
24
25struct semaphore {
26 atomic_t count;
27 atomic_t waking;
28 wait_queue_head_t wait;
29};
30
31#define __SEMAPHORE_INITIALIZER(name, n) \
32{ \
33 .count = ATOMIC_INIT(n), \
34 .waking = ATOMIC_INIT(0), \
35 .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
36}
37
38#define __MUTEX_INITIALIZER(name) \
39 __SEMAPHORE_INITIALIZER(name,1)
40
41#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
42 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
43
44#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
45#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
46
47extern inline void sema_init (struct semaphore *sem, int val)
48{
49 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
50}
51
52static inline void init_MUTEX (struct semaphore *sem)
53{
54 sema_init(sem, 1);
55}
56
57static inline void init_MUTEX_LOCKED (struct semaphore *sem)
58{
59 sema_init(sem, 0);
60}
61
62asmlinkage void __down_failed(void /* special register calling convention */);
63asmlinkage int __down_failed_interruptible(void /* params in registers */);
64asmlinkage int __down_failed_trylock(void /* params in registers */);
65asmlinkage void __up_wakeup(void /* special register calling convention */);
66
67asmlinkage void __down(struct semaphore * sem);
68asmlinkage int __down_interruptible(struct semaphore * sem);
69asmlinkage int __down_trylock(struct semaphore * sem);
70asmlinkage void __up(struct semaphore * sem);
71
72extern spinlock_t semaphore_wake_lock;
73
74/*
75 * This is ugly, but we want the default case to fall through.
76 * "down_failed" is a special asm handler that calls the C
77 * routine that actually waits. See arch/m68k/lib/semaphore.S
78 */
79extern inline void down(struct semaphore * sem)
80{
81 might_sleep();
82 __asm__ __volatile__(
83 "| atomic down operation\n\t"
84 "movel %0, %%a1\n\t"
85 "lea %%pc@(1f), %%a0\n\t"
86 "subql #1, %%a1@\n\t"
87 "jmi __down_failed\n"
88 "1:"
89 : /* no outputs */
90 : "g" (sem)
91 : "cc", "%a0", "%a1", "memory");
92}
93
94extern inline int down_interruptible(struct semaphore * sem)
95{
96 int ret;
97
98 might_sleep();
99 __asm__ __volatile__(
100 "| atomic down operation\n\t"
101 "movel %1, %%a1\n\t"
102 "lea %%pc@(1f), %%a0\n\t"
103 "subql #1, %%a1@\n\t"
104 "jmi __down_failed_interruptible\n\t"
105 "clrl %%d0\n"
106 "1: movel %%d0, %0\n"
107 : "=d" (ret)
108 : "g" (sem)
109 : "cc", "%d0", "%a0", "%a1", "memory");
110 return(ret);
111}
112
113extern inline int down_trylock(struct semaphore * sem)
114{
115 register struct semaphore *sem1 __asm__ ("%a1") = sem;
116 register int result __asm__ ("%d0");
117
118 __asm__ __volatile__(
119 "| atomic down trylock operation\n\t"
120 "subql #1,%1@\n\t"
121 "jmi 2f\n\t"
122 "clrl %0\n"
123 "1:\n"
124 ".section .text.lock,\"ax\"\n"
125 ".even\n"
126 "2:\tpea 1b\n\t"
127 "jbra __down_failed_trylock\n"
128 ".previous"
129 : "=d" (result)
130 : "a" (sem1)
131 : "memory");
132 return result;
133}
134
135/*
136 * Note! This is subtle. We jump to wake people up only if
137 * the semaphore was negative (== somebody was waiting on it).
138 * The default case (no contention) will result in NO
139 * jumps for both down() and up().
140 */
141extern inline void up(struct semaphore * sem)
142{
143 __asm__ __volatile__(
144 "| atomic up operation\n\t"
145 "movel %0, %%a1\n\t"
146 "lea %%pc@(1f), %%a0\n\t"
147 "addql #1, %%a1@\n\t"
148 "jle __up_wakeup\n"
149 "1:"
150 : /* no outputs */
151 : "g" (sem)
152 : "cc", "%a0", "%a1", "memory");
153}
154
155#endif /* __ASSEMBLY__ */
156
157#endif