blob: 5cc1fdd86f504ebb71bf8b1596aecd144615c688 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
39 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
40
41#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
42#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
43
Greg Ungererc514b8b2005-11-02 14:42:03 +100044static inline void sema_init (struct semaphore *sem, int val)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
46 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
47}
48
49static inline void init_MUTEX (struct semaphore *sem)
50{
51 sema_init(sem, 1);
52}
53
54static inline void init_MUTEX_LOCKED (struct semaphore *sem)
55{
56 sema_init(sem, 0);
57}
58
59asmlinkage void __down_failed(void /* special register calling convention */);
60asmlinkage int __down_failed_interruptible(void /* params in registers */);
61asmlinkage int __down_failed_trylock(void /* params in registers */);
62asmlinkage void __up_wakeup(void /* special register calling convention */);
63
64asmlinkage void __down(struct semaphore * sem);
65asmlinkage int __down_interruptible(struct semaphore * sem);
66asmlinkage int __down_trylock(struct semaphore * sem);
67asmlinkage void __up(struct semaphore * sem);
68
69extern spinlock_t semaphore_wake_lock;
70
71/*
72 * This is ugly, but we want the default case to fall through.
73 * "down_failed" is a special asm handler that calls the C
74 * routine that actually waits. See arch/m68k/lib/semaphore.S
75 */
Greg Ungererc514b8b2005-11-02 14:42:03 +100076static inline void down(struct semaphore * sem)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077{
78 might_sleep();
79 __asm__ __volatile__(
80 "| atomic down operation\n\t"
81 "movel %0, %%a1\n\t"
82 "lea %%pc@(1f), %%a0\n\t"
83 "subql #1, %%a1@\n\t"
84 "jmi __down_failed\n"
85 "1:"
86 : /* no outputs */
87 : "g" (sem)
88 : "cc", "%a0", "%a1", "memory");
89}
90
Greg Ungererc514b8b2005-11-02 14:42:03 +100091static inline int down_interruptible(struct semaphore * sem)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092{
93 int ret;
94
95 might_sleep();
96 __asm__ __volatile__(
97 "| atomic down operation\n\t"
98 "movel %1, %%a1\n\t"
99 "lea %%pc@(1f), %%a0\n\t"
100 "subql #1, %%a1@\n\t"
101 "jmi __down_failed_interruptible\n\t"
102 "clrl %%d0\n"
103 "1: movel %%d0, %0\n"
104 : "=d" (ret)
105 : "g" (sem)
106 : "cc", "%d0", "%a0", "%a1", "memory");
107 return(ret);
108}
109
Greg Ungererc514b8b2005-11-02 14:42:03 +1000110static inline int down_trylock(struct semaphore * sem)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111{
112 register struct semaphore *sem1 __asm__ ("%a1") = sem;
113 register int result __asm__ ("%d0");
114
115 __asm__ __volatile__(
116 "| atomic down trylock operation\n\t"
117 "subql #1,%1@\n\t"
118 "jmi 2f\n\t"
119 "clrl %0\n"
120 "1:\n"
121 ".section .text.lock,\"ax\"\n"
122 ".even\n"
123 "2:\tpea 1b\n\t"
124 "jbra __down_failed_trylock\n"
125 ".previous"
126 : "=d" (result)
127 : "a" (sem1)
128 : "memory");
129 return result;
130}
131
132/*
133 * Note! This is subtle. We jump to wake people up only if
134 * the semaphore was negative (== somebody was waiting on it).
135 * The default case (no contention) will result in NO
136 * jumps for both down() and up().
137 */
Greg Ungererc514b8b2005-11-02 14:42:03 +1000138static inline void up(struct semaphore * sem)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 __asm__ __volatile__(
141 "| atomic up operation\n\t"
142 "movel %0, %%a1\n\t"
143 "lea %%pc@(1f), %%a0\n\t"
144 "addql #1, %%a1@\n\t"
145 "jle __up_wakeup\n"
146 "1:"
147 : /* no outputs */
148 : "g" (sem)
149 : "cc", "%a0", "%a1", "memory");
150}
151
152#endif /* __ASSEMBLY__ */
153
154#endif