diff options
Diffstat (limited to 'include/asm-cris/semaphore.h')
-rw-r--r-- | include/asm-cris/semaphore.h | 134 |
1 files changed, 1 insertions, 133 deletions
diff --git a/include/asm-cris/semaphore.h b/include/asm-cris/semaphore.h index 31a4ac448195..d9b2034ed1d2 100644 --- a/include/asm-cris/semaphore.h +++ b/include/asm-cris/semaphore.h | |||
@@ -1,133 +1 @@ | |||
1 | /* $Id: semaphore.h,v 1.3 2001/05/08 13:54:09 bjornw Exp $ */ | #include <linux/semaphore.h> | |
2 | |||
3 | /* On the i386 these are coded in asm, perhaps we should as well. Later.. */ | ||
4 | |||
5 | #ifndef _CRIS_SEMAPHORE_H | ||
6 | #define _CRIS_SEMAPHORE_H | ||
7 | |||
8 | #define RW_LOCK_BIAS 0x01000000 | ||
9 | |||
10 | #include <linux/wait.h> | ||
11 | #include <linux/spinlock.h> | ||
12 | #include <linux/rwsem.h> | ||
13 | |||
14 | #include <asm/system.h> | ||
15 | #include <asm/atomic.h> | ||
16 | |||
17 | /* | ||
18 | * CRIS semaphores, implemented in C-only so far. | ||
19 | */ | ||
20 | |||
21 | struct semaphore { | ||
22 | atomic_t count; | ||
23 | atomic_t waking; | ||
24 | wait_queue_head_t wait; | ||
25 | }; | ||
26 | |||
27 | #define __SEMAPHORE_INITIALIZER(name, n) \ | ||
28 | { \ | ||
29 | .count = ATOMIC_INIT(n), \ | ||
30 | .waking = ATOMIC_INIT(0), \ | ||
31 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | ||
32 | } | ||
33 | |||
34 | #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ | ||
35 | struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) | ||
36 | |||
37 | #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) | ||
38 | |||
39 | static inline void sema_init(struct semaphore *sem, int val) | ||
40 | { | ||
41 | *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); | ||
42 | } | ||
43 | |||
44 | static inline void init_MUTEX (struct semaphore *sem) | ||
45 | { | ||
46 | sema_init(sem, 1); | ||
47 | } | ||
48 | |||
49 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | ||
50 | { | ||
51 | sema_init(sem, 0); | ||
52 | } | ||
53 | |||
54 | extern void __down(struct semaphore * sem); | ||
55 | extern int __down_interruptible(struct semaphore * sem); | ||
56 | extern int __down_trylock(struct semaphore * sem); | ||
57 | extern void __up(struct semaphore * sem); | ||
58 | |||
59 | /* notice - we probably can do cli/sti here instead of saving */ | ||
60 | |||
61 | static inline void down(struct semaphore * sem) | ||
62 | { | ||
63 | unsigned long flags; | ||
64 | int failed; | ||
65 | |||
66 | might_sleep(); | ||
67 | |||
68 | /* atomically decrement the semaphores count, and if its negative, we wait */ | ||
69 | cris_atomic_save(sem, flags); | ||
70 | failed = --(sem->count.counter) < 0; | ||
71 | cris_atomic_restore(sem, flags); | ||
72 | if(failed) { | ||
73 | __down(sem); | ||
74 | } | ||
75 | } | ||
76 | |||
77 | /* | ||
78 | * This version waits in interruptible state so that the waiting | ||
79 | * process can be killed. The down_interruptible routine | ||
80 | * returns negative for signalled and zero for semaphore acquired. | ||
81 | */ | ||
82 | |||
83 | static inline int down_interruptible(struct semaphore * sem) | ||
84 | { | ||
85 | unsigned long flags; | ||
86 | int failed; | ||
87 | |||
88 | might_sleep(); | ||
89 | |||
90 | /* atomically decrement the semaphores count, and if its negative, we wait */ | ||
91 | cris_atomic_save(sem, flags); | ||
92 | failed = --(sem->count.counter) < 0; | ||
93 | cris_atomic_restore(sem, flags); | ||
94 | if(failed) | ||
95 | failed = __down_interruptible(sem); | ||
96 | return(failed); | ||
97 | } | ||
98 | |||
99 | static inline int down_trylock(struct semaphore * sem) | ||
100 | { | ||
101 | unsigned long flags; | ||
102 | int failed; | ||
103 | |||
104 | cris_atomic_save(sem, flags); | ||
105 | failed = --(sem->count.counter) < 0; | ||
106 | cris_atomic_restore(sem, flags); | ||
107 | if(failed) | ||
108 | failed = __down_trylock(sem); | ||
109 | return(failed); | ||
110 | |||
111 | } | ||
112 | |||
113 | /* | ||
114 | * Note! This is subtle. We jump to wake people up only if | ||
115 | * the semaphore was negative (== somebody was waiting on it). | ||
116 | * The default case (no contention) will result in NO | ||
117 | * jumps for both down() and up(). | ||
118 | */ | ||
119 | static inline void up(struct semaphore * sem) | ||
120 | { | ||
121 | unsigned long flags; | ||
122 | int wakeup; | ||
123 | |||
124 | /* atomically increment the semaphores count, and if it was negative, we wake people */ | ||
125 | cris_atomic_save(sem, flags); | ||
126 | wakeup = ++(sem->count.counter) <= 0; | ||
127 | cris_atomic_restore(sem, flags); | ||
128 | if(wakeup) { | ||
129 | __up(sem); | ||
130 | } | ||
131 | } | ||
132 | |||
133 | #endif | ||