1#ifndef __LINUX_RWLOCK_H
2#define __LINUX_RWLOCK_H
3
4#ifndef __LINUX_SPINLOCK_H
5# error "please don't include this file directly"
6#endif
7
8/*
9 * rwlock related methods
10 *
11 * split out from spinlock.h
12 *
13 * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
14 * Released under the General Public License (GPL).
15 */
16
17#ifdef CONFIG_DEBUG_SPINLOCK
18  extern void __rwlock_init(rwlock_t *lock, const char *name,
19			    struct lock_class_key *key);
20# define rwlock_init(lock)					\
21do {								\
22	static struct lock_class_key __key;			\
23								\
24	__rwlock_init((lock), #lock, &__key);			\
25} while (0)
26#else
27# define rwlock_init(lock)					\
28	do { *(lock) = __RW_LOCK_UNLOCKED(lock); } while (0)
29#endif
30
31#ifdef CONFIG_DEBUG_SPINLOCK
32 extern void do_raw_read_lock(rwlock_t *lock) __acquires(lock);
33#define do_raw_read_lock_flags(lock, flags) do_raw_read_lock(lock)
34 extern int do_raw_read_trylock(rwlock_t *lock);
35 extern void do_raw_read_unlock(rwlock_t *lock) __releases(lock);
36 extern void do_raw_write_lock(rwlock_t *lock) __acquires(lock);
37#define do_raw_write_lock_flags(lock, flags) do_raw_write_lock(lock)
38 extern int do_raw_write_trylock(rwlock_t *lock);
39 extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock);
40#else
41# define do_raw_read_lock(rwlock)	do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
42# define do_raw_read_lock_flags(lock, flags) \
43		do {__acquire(lock); arch_read_lock_flags(&(lock)->raw_lock, *(flags)); } while (0)
44# define do_raw_read_trylock(rwlock)	arch_read_trylock(&(rwlock)->raw_lock)
45# define do_raw_read_unlock(rwlock)	do {arch_read_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
46# define do_raw_write_lock(rwlock)	do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
47# define do_raw_write_lock_flags(lock, flags) \
48		do {__acquire(lock); arch_write_lock_flags(&(lock)->raw_lock, *(flags)); } while (0)
49# define do_raw_write_trylock(rwlock)	arch_write_trylock(&(rwlock)->raw_lock)
50# define do_raw_write_unlock(rwlock)	do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
51#endif
52
53#define read_can_lock(rwlock)		arch_read_can_lock(&(rwlock)->raw_lock)
54#define write_can_lock(rwlock)		arch_write_can_lock(&(rwlock)->raw_lock)
55
56/*
57 * Define the various rw_lock methods.  Note we define these
58 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
59 * methods are defined as nops in the case they are not required.
60 */
61#define read_trylock(lock)	__cond_lock(lock, _raw_read_trylock(lock))
62#define write_trylock(lock)	__cond_lock(lock, _raw_write_trylock(lock))
63
64#define write_lock(lock)	_raw_write_lock(lock)
65#define read_lock(lock)		_raw_read_lock(lock)
66
67#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
68
69#define read_lock_irqsave(lock, flags)			\
70	do {						\
71		typecheck(unsigned long, flags);	\
72		flags = _raw_read_lock_irqsave(lock);	\
73	} while (0)
74#define write_lock_irqsave(lock, flags)			\
75	do {						\
76		typecheck(unsigned long, flags);	\
77		flags = _raw_write_lock_irqsave(lock);	\
78	} while (0)
79
80#else
81
82#define read_lock_irqsave(lock, flags)			\
83	do {						\
84		typecheck(unsigned long, flags);	\
85		_raw_read_lock_irqsave(lock, flags);	\
86	} while (0)
87#define write_lock_irqsave(lock, flags)			\
88	do {						\
89		typecheck(unsigned long, flags);	\
90		_raw_write_lock_irqsave(lock, flags);	\
91	} while (0)
92
93#endif
94
95#define read_lock_irq(lock)		_raw_read_lock_irq(lock)
96#define read_lock_bh(lock)		_raw_read_lock_bh(lock)
97#define write_lock_irq(lock)		_raw_write_lock_irq(lock)
98#define write_lock_bh(lock)		_raw_write_lock_bh(lock)
99#define read_unlock(lock)		_raw_read_unlock(lock)
100#define write_unlock(lock)		_raw_write_unlock(lock)
101#define read_unlock_irq(lock)		_raw_read_unlock_irq(lock)
102#define write_unlock_irq(lock)		_raw_write_unlock_irq(lock)
103
104#define read_unlock_irqrestore(lock, flags)			\
105	do {							\
106		typecheck(unsigned long, flags);		\
107		_raw_read_unlock_irqrestore(lock, flags);	\
108	} while (0)
109#define read_unlock_bh(lock)		_raw_read_unlock_bh(lock)
110
111#define write_unlock_irqrestore(lock, flags)		\
112	do {						\
113		typecheck(unsigned long, flags);	\
114		_raw_write_unlock_irqrestore(lock, flags);	\
115	} while (0)
116#define write_unlock_bh(lock)		_raw_write_unlock_bh(lock)
117
118#define write_trylock_irqsave(lock, flags) \
119({ \
120	local_irq_save(flags); \
121	write_trylock(lock) ? \
122	1 : ({ local_irq_restore(flags); 0; }); \
123})
124
125#endif /* __LINUX_RWLOCK_H */
126