diff options
Diffstat (limited to 'include/asm-parisc/semaphore.h')
-rw-r--r-- | include/asm-parisc/semaphore.h | 146 |
1 files changed, 1 insertions, 145 deletions
diff --git a/include/asm-parisc/semaphore.h b/include/asm-parisc/semaphore.h index a16271cdc748..d9b2034ed1d2 100644 --- a/include/asm-parisc/semaphore.h +++ b/include/asm-parisc/semaphore.h | |||
@@ -1,145 +1 @@ | |||
1 | /* SMP- and interrupt-safe semaphores. | #include <linux/semaphore.h> | |
2 | * PA-RISC version by Matthew Wilcox | ||
3 | * | ||
4 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) | ||
5 | * Copyright (C) 1996 Linus Torvalds | ||
6 | * Copyright (C) 1999-2001 Matthew Wilcox < willy at debian d0T org > | ||
7 | * Copyright (C) 2000 Grant Grundler < grundler a debian org > | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or modify | ||
10 | * it under the terms of the GNU General Public License as published by | ||
11 | * the Free Software Foundation; either version 2 of the License, or | ||
12 | * (at your option) any later version. | ||
13 | * | ||
14 | * This program is distributed in the hope that it will be useful, | ||
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
17 | * GNU General Public License for more details. | ||
18 | * | ||
19 | * You should have received a copy of the GNU General Public License | ||
20 | * along with this program; if not, write to the Free Software | ||
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
22 | */ | ||
23 | |||
24 | #ifndef _ASM_PARISC_SEMAPHORE_H | ||
25 | #define _ASM_PARISC_SEMAPHORE_H | ||
26 | |||
27 | #include <linux/spinlock.h> | ||
28 | #include <linux/wait.h> | ||
29 | #include <linux/rwsem.h> | ||
30 | |||
31 | #include <asm/system.h> | ||
32 | |||
33 | /* | ||
34 | * The `count' is initialised to the number of people who are allowed to | ||
35 | * take the lock. (Normally we want a mutex, so this is `1'). if | ||
36 | * `count' is positive, the lock can be taken. if it's 0, no-one is | ||
37 | * waiting on it. if it's -1, at least one task is waiting. | ||
38 | */ | ||
39 | struct semaphore { | ||
40 | spinlock_t sentry; | ||
41 | int count; | ||
42 | wait_queue_head_t wait; | ||
43 | }; | ||
44 | |||
45 | #define __SEMAPHORE_INITIALIZER(name, n) \ | ||
46 | { \ | ||
47 | .sentry = SPIN_LOCK_UNLOCKED, \ | ||
48 | .count = n, \ | ||
49 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | ||
50 | } | ||
51 | |||
52 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ | ||
53 | struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) | ||
54 | |||
55 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | ||
56 | |||
57 | static inline void sema_init (struct semaphore *sem, int val) | ||
58 | { | ||
59 | *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); | ||
60 | } | ||
61 | |||
62 | static inline void init_MUTEX (struct semaphore *sem) | ||
63 | { | ||
64 | sema_init(sem, 1); | ||
65 | } | ||
66 | |||
67 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | ||
68 | { | ||
69 | sema_init(sem, 0); | ||
70 | } | ||
71 | |||
72 | static inline int sem_getcount(struct semaphore *sem) | ||
73 | { | ||
74 | return sem->count; | ||
75 | } | ||
76 | |||
77 | asmlinkage void __down(struct semaphore * sem); | ||
78 | asmlinkage int __down_interruptible(struct semaphore * sem); | ||
79 | asmlinkage void __up(struct semaphore * sem); | ||
80 | |||
81 | /* Semaphores can be `tried' from irq context. So we have to disable | ||
82 | * interrupts while we're messing with the semaphore. Sorry. | ||
83 | */ | ||
84 | |||
85 | static inline void down(struct semaphore * sem) | ||
86 | { | ||
87 | might_sleep(); | ||
88 | spin_lock_irq(&sem->sentry); | ||
89 | if (sem->count > 0) { | ||
90 | sem->count--; | ||
91 | } else { | ||
92 | __down(sem); | ||
93 | } | ||
94 | spin_unlock_irq(&sem->sentry); | ||
95 | } | ||
96 | |||
97 | static inline int down_interruptible(struct semaphore * sem) | ||
98 | { | ||
99 | int ret = 0; | ||
100 | might_sleep(); | ||
101 | spin_lock_irq(&sem->sentry); | ||
102 | if (sem->count > 0) { | ||
103 | sem->count--; | ||
104 | } else { | ||
105 | ret = __down_interruptible(sem); | ||
106 | } | ||
107 | spin_unlock_irq(&sem->sentry); | ||
108 | return ret; | ||
109 | } | ||
110 | |||
111 | /* | ||
112 | * down_trylock returns 0 on success, 1 if we failed to get the lock. | ||
113 | * May not sleep, but must preserve irq state | ||
114 | */ | ||
115 | static inline int down_trylock(struct semaphore * sem) | ||
116 | { | ||
117 | unsigned long flags; | ||
118 | int count; | ||
119 | |||
120 | spin_lock_irqsave(&sem->sentry, flags); | ||
121 | count = sem->count - 1; | ||
122 | if (count >= 0) | ||
123 | sem->count = count; | ||
124 | spin_unlock_irqrestore(&sem->sentry, flags); | ||
125 | return (count < 0); | ||
126 | } | ||
127 | |||
128 | /* | ||
129 | * Note! This is subtle. We jump to wake people up only if | ||
130 | * the semaphore was negative (== somebody was waiting on it). | ||
131 | */ | ||
132 | static inline void up(struct semaphore * sem) | ||
133 | { | ||
134 | unsigned long flags; | ||
135 | |||
136 | spin_lock_irqsave(&sem->sentry, flags); | ||
137 | if (sem->count < 0) { | ||
138 | __up(sem); | ||
139 | } else { | ||
140 | sem->count++; | ||
141 | } | ||
142 | spin_unlock_irqrestore(&sem->sentry, flags); | ||
143 | } | ||
144 | |||
145 | #endif /* _ASM_PARISC_SEMAPHORE_H */ | ||