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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 | ||
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 | ||
47 | extern inline void sema_init (struct semaphore *sem, int val) | |
48 | { | |
49 | *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); | |
50 | } | |
51 | ||
52 | static inline void init_MUTEX (struct semaphore *sem) | |
53 | { | |
54 | sema_init(sem, 1); | |
55 | } | |
56 | ||
57 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | |
58 | { | |
59 | sema_init(sem, 0); | |
60 | } | |
61 | ||
62 | asmlinkage void __down_failed(void /* special register calling convention */); | |
63 | asmlinkage int __down_failed_interruptible(void /* params in registers */); | |
64 | asmlinkage int __down_failed_trylock(void /* params in registers */); | |
65 | asmlinkage void __up_wakeup(void /* special register calling convention */); | |
66 | ||
67 | asmlinkage void __down(struct semaphore * sem); | |
68 | asmlinkage int __down_interruptible(struct semaphore * sem); | |
69 | asmlinkage int __down_trylock(struct semaphore * sem); | |
70 | asmlinkage void __up(struct semaphore * sem); | |
71 | ||
72 | extern 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 | */ | |
79 | extern 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 | ||
94 | extern 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 | ||
113 | extern 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 | */ | |
141 | extern 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 |