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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [include/] [asm-ppc/] [semaphore.h] - Blame information for rev 1774

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#ifndef _PPC_SEMAPHORE_H
#define _PPC_SEMAPHORE_H
 
/*
 * Swiped from asm-sparc/semaphore.h and modified
 * -- Cort (cort@cs.nmt.edu)
 *
 * Stole some rw spinlock-based semaphore stuff from asm-alpha/semaphore.h
 * -- Ani Joshi (ajoshi@unixbox.com)
 *
 * Remove spinlock-based RW semaphores; RW semaphore definitions are
 * now in rwsem.h and we use the generic lib/rwsem.c implementation.
 * Rework semaphores to use atomic_dec_if_positive.
 * -- Paul Mackerras (paulus@samba.org)
 */
 
#ifdef __KERNEL__
 
#include <asm/atomic.h>
#include <asm/system.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
 
struct semaphore {
        /*
         * Note that any negative value of count is equivalent to 0,
         * but additionally indicates that some process(es) might be
         * sleeping on `wait'.
         */
        atomic_t count;
        wait_queue_head_t wait;
#if WAITQUEUE_DEBUG
        long __magic;
#endif
};
 
#if WAITQUEUE_DEBUG
# define __SEM_DEBUG_INIT(name) \
                , (long)&(name).__magic
#else
# define __SEM_DEBUG_INIT(name)
#endif
 
#define __SEMAPHORE_INITIALIZER(name, count) \
        { ATOMIC_INIT(count), \
          __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
          __SEM_DEBUG_INIT(name) }
 
#define __MUTEX_INITIALIZER(name) \
        __SEMAPHORE_INITIALIZER(name, 1)
 
#define __DECLARE_SEMAPHORE_GENERIC(name, count) \
        struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
 
#define DECLARE_MUTEX(name)             __DECLARE_SEMAPHORE_GENERIC(name, 1)
#define DECLARE_MUTEX_LOCKED(name)      __DECLARE_SEMAPHORE_GENERIC(name, 0)
 
static inline void sema_init (struct semaphore *sem, int val)
{
        atomic_set(&sem->count, val);
        init_waitqueue_head(&sem->wait);
#if WAITQUEUE_DEBUG
        sem->__magic = (long)&sem->__magic;
#endif
}
 
static inline void init_MUTEX (struct semaphore *sem)
{
        sema_init(sem, 1);
}
 
static inline void init_MUTEX_LOCKED (struct semaphore *sem)
{
        sema_init(sem, 0);
}
 
extern void __down(struct semaphore * sem);
extern int  __down_interruptible(struct semaphore * sem);
extern void __up(struct semaphore * sem);
 
extern inline void down(struct semaphore * sem)
{
#if WAITQUEUE_DEBUG
        CHECK_MAGIC(sem->__magic);
#endif
 
        /*
         * Try to get the semaphore, take the slow path if we fail.
         */
        if (atomic_dec_return(&sem->count) < 0)
                __down(sem);
        smp_wmb();
}
 
extern inline int down_interruptible(struct semaphore * sem)
{
        int ret = 0;
 
#if WAITQUEUE_DEBUG
        CHECK_MAGIC(sem->__magic);
#endif
 
        if (atomic_dec_return(&sem->count) < 0)
                ret = __down_interruptible(sem);
        smp_wmb();
        return ret;
}
 
extern inline int down_trylock(struct semaphore * sem)
{
        int ret;
 
#if WAITQUEUE_DEBUG
        CHECK_MAGIC(sem->__magic);
#endif
 
        ret = atomic_dec_if_positive(&sem->count) < 0;
        smp_wmb();
        return ret;
}
 
extern inline void up(struct semaphore * sem)
{
#if WAITQUEUE_DEBUG
        CHECK_MAGIC(sem->__magic);
#endif
 
        smp_wmb();
        if (atomic_inc_return(&sem->count) <= 0)
                __up(sem);
}
 
static inline int sem_getcount(struct semaphore *sem)
{
        return atomic_read(&sem->count);
}
 
#endif /* __KERNEL__ */
 
#endif /* !(_PPC_SEMAPHORE_H) */

Line No.	Rev	Author	Line
1	1276	phoenix	`#ifndef _PPC_SEMAPHORE_H`
2			`#define _PPC_SEMAPHORE_H`
3
4			`/*`
5			`* Swiped from asm-sparc/semaphore.h and modified`
6			`* -- Cort (cort@cs.nmt.edu)`
7			`*`
8			`* Stole some rw spinlock-based semaphore stuff from asm-alpha/semaphore.h`
9			`* -- Ani Joshi (ajoshi@unixbox.com)`
10			`*`
11			`* Remove spinlock-based RW semaphores; RW semaphore definitions are`
12			`* now in rwsem.h and we use the generic lib/rwsem.c implementation.`
13			`* Rework semaphores to use atomic_dec_if_positive.`
14			`* -- Paul Mackerras (paulus@samba.org)`
15			`*/`
16
17			`#ifdef __KERNEL__`
18
19			`#include <asm/atomic.h>`
20			`#include <asm/system.h>`
21			`#include <linux/wait.h>`
22			`#include <linux/rwsem.h>`
23
24			`struct semaphore {`
25			`/*`
26			`* Note that any negative value of count is equivalent to 0,`
27			`* but additionally indicates that some process(es) might be`
28			* sleeping on `wait'.
29			`*/`
30			`atomic_t count;`
31			`wait_queue_head_t wait;`
32			`#if WAITQUEUE_DEBUG`
33			`long __magic;`
34			`#endif`
35			`};`
36
37			`#if WAITQUEUE_DEBUG`
38			`# define __SEM_DEBUG_INIT(name) \`
39			`, (long)&(name).__magic`
40			`#else`
41			`# define __SEM_DEBUG_INIT(name)`
42			`#endif`
43
44			`#define __SEMAPHORE_INITIALIZER(name, count) \`
45			`{ ATOMIC_INIT(count), \`
46			`__WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \`
47			`__SEM_DEBUG_INIT(name) }`
48
49			`#define __MUTEX_INITIALIZER(name) \`
50			`__SEMAPHORE_INITIALIZER(name, 1)`
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			`#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name, 0)`
57
58			`static inline void sema_init (struct semaphore *sem, int val)`
59			`{`
60			`atomic_set(&sem->count, val);`
61			`init_waitqueue_head(&sem->wait);`
62			`#if WAITQUEUE_DEBUG`
63			`sem->__magic = (long)&sem->__magic;`
64			`#endif`
65			`}`
66
67			`static inline void init_MUTEX (struct semaphore *sem)`
68			`{`
69			`sema_init(sem, 1);`
70			`}`
71
72			`static inline void init_MUTEX_LOCKED (struct semaphore *sem)`
73			`{`
74			`sema_init(sem, 0);`
75			`}`
76
77			`extern void __down(struct semaphore * sem);`
78			`extern int __down_interruptible(struct semaphore * sem);`
79			`extern void __up(struct semaphore * sem);`
80
81			`extern inline void down(struct semaphore * sem)`
82			`{`
83			`#if WAITQUEUE_DEBUG`
84			`CHECK_MAGIC(sem->__magic);`
85			`#endif`
86
87			`/*`
88			`* Try to get the semaphore, take the slow path if we fail.`
89			`*/`
90			`if (atomic_dec_return(&sem->count) < 0)`
91			`__down(sem);`
92			`smp_wmb();`
93			`}`
94
95			`extern inline int down_interruptible(struct semaphore * sem)`
96			`{`
97			`int ret = 0;`
98
99			`#if WAITQUEUE_DEBUG`
100			`CHECK_MAGIC(sem->__magic);`
101			`#endif`
102
103			`if (atomic_dec_return(&sem->count) < 0)`
104			`ret = __down_interruptible(sem);`
105			`smp_wmb();`
106			`return ret;`
107			`}`
108
109			`extern inline int down_trylock(struct semaphore * sem)`
110			`{`
111			`int ret;`
112
113			`#if WAITQUEUE_DEBUG`
114			`CHECK_MAGIC(sem->__magic);`
115			`#endif`
116
117			`ret = atomic_dec_if_positive(&sem->count) < 0;`
118			`smp_wmb();`
119			`return ret;`
120			`}`
121
122			`extern inline void up(struct semaphore * sem)`
123			`{`
124			`#if WAITQUEUE_DEBUG`
125			`CHECK_MAGIC(sem->__magic);`
126			`#endif`
127
128			`smp_wmb();`
129			`if (atomic_inc_return(&sem->count) <= 0)`
130			`__up(sem);`
131			`}`
132
133			`static inline int sem_getcount(struct semaphore *sem)`
134			`{`
135			`return atomic_read(&sem->count);`
136			`}`
137
138			`#endif /* __KERNEL__ */`
139
140			`#endif /* !(_PPC_SEMAPHORE_H) */`

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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [include/] [asm-ppc/] [semaphore.h] - Blame information for rev 1774