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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 | #include <linux/stringify.h> | |
13 | ||
14 | #include <asm/system.h> | |
15 | #include <asm/atomic.h> | |
16 | ||
17 | /* | |
18 | * Interrupt-safe semaphores.. | |
19 | * | |
20 | * (C) Copyright 1996 Linus Torvalds | |
21 | * | |
22 | * m68k version by Andreas Schwab | |
23 | */ | |
24 | ||
25 | ||
26 | struct semaphore { | |
27 | atomic_t count; | |
28 | atomic_t waking; | |
29 | wait_queue_head_t wait; | |
30 | }; | |
31 | ||
32 | #define __SEMAPHORE_INITIALIZER(name, n) \ | |
33 | { \ | |
34 | .count = ATOMIC_INIT(n), \ | |
35 | .waking = ATOMIC_INIT(0), \ | |
36 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | |
37 | } | |
38 | ||
1da177e4 LT |
39 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ |
40 | struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) | |
41 | ||
42 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | |
43 | #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) | |
44 | ||
45 | static inline void sema_init(struct semaphore *sem, int val) | |
46 | { | |
47 | *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); | |
48 | } | |
49 | ||
50 | static inline void init_MUTEX (struct semaphore *sem) | |
51 | { | |
52 | sema_init(sem, 1); | |
53 | } | |
54 | ||
55 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | |
56 | { | |
57 | sema_init(sem, 0); | |
58 | } | |
59 | ||
60 | asmlinkage void __down_failed(void /* special register calling convention */); | |
61 | asmlinkage int __down_failed_interruptible(void /* params in registers */); | |
62 | asmlinkage int __down_failed_trylock(void /* params in registers */); | |
63 | asmlinkage void __up_wakeup(void /* special register calling convention */); | |
64 | ||
65 | asmlinkage void __down(struct semaphore * sem); | |
66 | asmlinkage int __down_interruptible(struct semaphore * sem); | |
67 | asmlinkage int __down_trylock(struct semaphore * sem); | |
68 | asmlinkage void __up(struct semaphore * sem); | |
69 | ||
70 | /* | |
71 | * This is ugly, but we want the default case to fall through. | |
72 | * "down_failed" is a special asm handler that calls the C | |
73 | * routine that actually waits. See arch/m68k/lib/semaphore.S | |
74 | */ | |
75 | static inline void down(struct semaphore *sem) | |
76 | { | |
77 | register struct semaphore *sem1 __asm__ ("%a1") = sem; | |
78 | ||
79 | might_sleep(); | |
80 | __asm__ __volatile__( | |
81 | "| atomic down operation\n\t" | |
82 | "subql #1,%0@\n\t" | |
83 | "jmi 2f\n\t" | |
84 | "1:\n" | |
85 | LOCK_SECTION_START(".even\n\t") | |
86 | "2:\tpea 1b\n\t" | |
87 | "jbra __down_failed\n" | |
88 | LOCK_SECTION_END | |
89 | : /* no outputs */ | |
90 | : "a" (sem1) | |
91 | : "memory"); | |
92 | } | |
93 | ||
94 | static inline int down_interruptible(struct semaphore *sem) | |
95 | { | |
96 | register struct semaphore *sem1 __asm__ ("%a1") = sem; | |
97 | register int result __asm__ ("%d0"); | |
98 | ||
99 | might_sleep(); | |
100 | __asm__ __volatile__( | |
101 | "| atomic interruptible down operation\n\t" | |
102 | "subql #1,%1@\n\t" | |
103 | "jmi 2f\n\t" | |
104 | "clrl %0\n" | |
105 | "1:\n" | |
106 | LOCK_SECTION_START(".even\n\t") | |
107 | "2:\tpea 1b\n\t" | |
108 | "jbra __down_failed_interruptible\n" | |
109 | LOCK_SECTION_END | |
110 | : "=d" (result) | |
111 | : "a" (sem1) | |
112 | : "memory"); | |
113 | return result; | |
114 | } | |
115 | ||
116 | static inline int down_trylock(struct semaphore *sem) | |
117 | { | |
118 | register struct semaphore *sem1 __asm__ ("%a1") = sem; | |
119 | register int result __asm__ ("%d0"); | |
120 | ||
121 | __asm__ __volatile__( | |
122 | "| atomic down trylock operation\n\t" | |
123 | "subql #1,%1@\n\t" | |
124 | "jmi 2f\n\t" | |
125 | "clrl %0\n" | |
126 | "1:\n" | |
127 | LOCK_SECTION_START(".even\n\t") | |
128 | "2:\tpea 1b\n\t" | |
129 | "jbra __down_failed_trylock\n" | |
130 | LOCK_SECTION_END | |
131 | : "=d" (result) | |
132 | : "a" (sem1) | |
133 | : "memory"); | |
134 | return result; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Note! This is subtle. We jump to wake people up only if | |
139 | * the semaphore was negative (== somebody was waiting on it). | |
140 | * The default case (no contention) will result in NO | |
141 | * jumps for both down() and up(). | |
142 | */ | |
143 | static inline void up(struct semaphore *sem) | |
144 | { | |
145 | register struct semaphore *sem1 __asm__ ("%a1") = sem; | |
146 | ||
147 | __asm__ __volatile__( | |
148 | "| atomic up operation\n\t" | |
149 | "addql #1,%0@\n\t" | |
150 | "jle 2f\n" | |
151 | "1:\n" | |
152 | LOCK_SECTION_START(".even\n\t") | |
153 | "2:\t" | |
154 | "pea 1b\n\t" | |
155 | "jbra __up_wakeup\n" | |
156 | LOCK_SECTION_END | |
157 | : /* no outputs */ | |
158 | : "a" (sem1) | |
159 | : "memory"); | |
160 | } | |
161 | ||
162 | #endif /* __ASSEMBLY__ */ | |
163 | ||
164 | #endif |