diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-sh/semaphore.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-sh/semaphore.h')
-rw-r--r-- | include/asm-sh/semaphore.h | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/include/asm-sh/semaphore.h b/include/asm-sh/semaphore.h new file mode 100644 index 000000000000..b923a77a8a7e --- /dev/null +++ b/include/asm-sh/semaphore.h | |||
@@ -0,0 +1,119 @@ | |||
1 | #ifndef __ASM_SH_SEMAPHORE_H | ||
2 | #define __ASM_SH_SEMAPHORE_H | ||
3 | |||
4 | #include <linux/linkage.h> | ||
5 | |||
6 | #ifdef __KERNEL__ | ||
7 | /* | ||
8 | * SMP- and interrupt-safe semaphores. | ||
9 | * | ||
10 | * (C) Copyright 1996 Linus Torvalds | ||
11 | * | ||
12 | * SuperH verison by Niibe Yutaka | ||
13 | * (Currently no asm implementation but generic C code...) | ||
14 | */ | ||
15 | |||
16 | #include <linux/spinlock.h> | ||
17 | #include <linux/rwsem.h> | ||
18 | #include <linux/wait.h> | ||
19 | |||
20 | #include <asm/system.h> | ||
21 | #include <asm/atomic.h> | ||
22 | |||
23 | struct semaphore { | ||
24 | atomic_t count; | ||
25 | int sleepers; | ||
26 | wait_queue_head_t wait; | ||
27 | }; | ||
28 | |||
29 | #define __SEMAPHORE_INITIALIZER(name, n) \ | ||
30 | { \ | ||
31 | .count = ATOMIC_INIT(n), \ | ||
32 | .sleepers = 0, \ | ||
33 | .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ | ||
34 | } | ||
35 | |||
36 | #define __MUTEX_INITIALIZER(name) \ | ||
37 | __SEMAPHORE_INITIALIZER(name,1) | ||
38 | |||
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 | /* | ||
48 | * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); | ||
49 | * | ||
50 | * i'd rather use the more flexible initialization above, but sadly | ||
51 | * GCC 2.7.2.3 emits a bogus warning. EGCS doesn't. Oh well. | ||
52 | */ | ||
53 | atomic_set(&sem->count, val); | ||
54 | sem->sleepers = 0; | ||
55 | init_waitqueue_head(&sem->wait); | ||
56 | } | ||
57 | |||
58 | static inline void init_MUTEX (struct semaphore *sem) | ||
59 | { | ||
60 | sema_init(sem, 1); | ||
61 | } | ||
62 | |||
63 | static inline void init_MUTEX_LOCKED (struct semaphore *sem) | ||
64 | { | ||
65 | sema_init(sem, 0); | ||
66 | } | ||
67 | |||
68 | #if 0 | ||
69 | asmlinkage void __down_failed(void /* special register calling convention */); | ||
70 | asmlinkage int __down_failed_interruptible(void /* params in registers */); | ||
71 | asmlinkage int __down_failed_trylock(void /* params in registers */); | ||
72 | asmlinkage void __up_wakeup(void /* special register calling convention */); | ||
73 | #endif | ||
74 | |||
75 | asmlinkage void __down(struct semaphore * sem); | ||
76 | asmlinkage int __down_interruptible(struct semaphore * sem); | ||
77 | asmlinkage int __down_trylock(struct semaphore * sem); | ||
78 | asmlinkage void __up(struct semaphore * sem); | ||
79 | |||
80 | extern spinlock_t semaphore_wake_lock; | ||
81 | |||
82 | static inline void down(struct semaphore * sem) | ||
83 | { | ||
84 | might_sleep(); | ||
85 | if (atomic_dec_return(&sem->count) < 0) | ||
86 | __down(sem); | ||
87 | } | ||
88 | |||
89 | static inline int down_interruptible(struct semaphore * sem) | ||
90 | { | ||
91 | int ret = 0; | ||
92 | |||
93 | might_sleep(); | ||
94 | if (atomic_dec_return(&sem->count) < 0) | ||
95 | ret = __down_interruptible(sem); | ||
96 | return ret; | ||
97 | } | ||
98 | |||
99 | static inline int down_trylock(struct semaphore * sem) | ||
100 | { | ||
101 | int ret = 0; | ||
102 | |||
103 | if (atomic_dec_return(&sem->count) < 0) | ||
104 | ret = __down_trylock(sem); | ||
105 | return ret; | ||
106 | } | ||
107 | |||
108 | /* | ||
109 | * Note! This is subtle. We jump to wake people up only if | ||
110 | * the semaphore was negative (== somebody was waiting on it). | ||
111 | */ | ||
112 | static inline void up(struct semaphore * sem) | ||
113 | { | ||
114 | if (atomic_inc_return(&sem->count) <= 0) | ||
115 | __up(sem); | ||
116 | } | ||
117 | |||
118 | #endif | ||
119 | #endif /* __ASM_SH_SEMAPHORE_H */ | ||