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1da177e4 LT |
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 | ||
25 | struct 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 | ||
1da177e4 LT |
38 | #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 | ||
c514b8be | 44 | static inline void sema_init (struct semaphore *sem, int val) |
1da177e4 LT |
45 | { |
46 | *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); | |
47 | } | |
48 | ||
49 | static inline void init_MUTEX (struct semaphore *sem) | |
50 | { | |
51 | sema_init(sem, 1); | |
52 | } | |
53 | ||
54 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | |
55 | { | |
56 | sema_init(sem, 0); | |
57 | } | |
58 | ||
59 | asmlinkage void __down_failed(void /* special register calling convention */); | |
60 | asmlinkage int __down_failed_interruptible(void /* params in registers */); | |
61 | asmlinkage int __down_failed_trylock(void /* params in registers */); | |
62 | asmlinkage void __up_wakeup(void /* special register calling convention */); | |
63 | ||
64 | asmlinkage void __down(struct semaphore * sem); | |
65 | asmlinkage int __down_interruptible(struct semaphore * sem); | |
66 | asmlinkage int __down_trylock(struct semaphore * sem); | |
67 | asmlinkage void __up(struct semaphore * sem); | |
68 | ||
69 | extern 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 | */ | |
c514b8be | 76 | static inline void down(struct semaphore * sem) |
1da177e4 LT |
77 | { |
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 | ||
c514b8be | 91 | static inline int down_interruptible(struct semaphore * sem) |
1da177e4 LT |
92 | { |
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 | ||
c514b8be | 110 | static inline int down_trylock(struct semaphore * sem) |
1da177e4 LT |
111 | { |
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 | */ | |
c514b8be | 138 | static inline void up(struct semaphore * sem) |
1da177e4 LT |
139 | { |
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 |