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
42#ifndef arch_read_lock_flags
43# define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
44#endif
45
46#ifndef arch_write_lock_flags
47# define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
48#endif
49
50# define do_raw_read_lock(rwlock) do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
51# define do_raw_read_lock_flags(lock, flags) \
52 do {__acquire(lock); arch_read_lock_flags(&(lock)->raw_lock, *(flags)); } while (0)
53# define do_raw_read_trylock(rwlock) arch_read_trylock(&(rwlock)->raw_lock)
54# define do_raw_read_unlock(rwlock) do {arch_read_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
55# define do_raw_write_lock(rwlock) do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
56# define do_raw_write_lock_flags(lock, flags) \
57 do {__acquire(lock); arch_write_lock_flags(&(lock)->raw_lock, *(flags)); } while (0)
58# define do_raw_write_trylock(rwlock) arch_write_trylock(&(rwlock)->raw_lock)
59# define do_raw_write_unlock(rwlock) do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
60#endif
61
62/*
63 * Define the various rw_lock methods. Note we define these
64 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
65 * methods are defined as nops in the case they are not required.
66 */
67#define read_trylock(lock) __cond_lock(lock, _raw_read_trylock(lock))
68#define write_trylock(lock) __cond_lock(lock, _raw_write_trylock(lock))
69
70#define write_lock(lock) _raw_write_lock(lock)
71#define read_lock(lock) _raw_read_lock(lock)
72
73#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
74
75#define read_lock_irqsave(lock, flags) \
76 do { \
77 typecheck(unsigned long, flags); \
78 flags = _raw_read_lock_irqsave(lock); \
79 } while (0)
80#define write_lock_irqsave(lock, flags) \
81 do { \
82 typecheck(unsigned long, flags); \
83 flags = _raw_write_lock_irqsave(lock); \
84 } while (0)
85
86#else
87
88#define read_lock_irqsave(lock, flags) \
89 do { \
90 typecheck(unsigned long, flags); \
91 _raw_read_lock_irqsave(lock, flags); \
92 } while (0)
93#define write_lock_irqsave(lock, flags) \
94 do { \
95 typecheck(unsigned long, flags); \
96 _raw_write_lock_irqsave(lock, flags); \
97 } while (0)
98
99#endif
100
101#define read_lock_irq(lock) _raw_read_lock_irq(lock)
102#define read_lock_bh(lock) _raw_read_lock_bh(lock)
103#define write_lock_irq(lock) _raw_write_lock_irq(lock)
104#define write_lock_bh(lock) _raw_write_lock_bh(lock)
105#define read_unlock(lock) _raw_read_unlock(lock)
106#define write_unlock(lock) _raw_write_unlock(lock)
107#define read_unlock_irq(lock) _raw_read_unlock_irq(lock)
108#define write_unlock_irq(lock) _raw_write_unlock_irq(lock)
109
110#define read_unlock_irqrestore(lock, flags) \
111 do { \
112 typecheck(unsigned long, flags); \
113 _raw_read_unlock_irqrestore(lock, flags); \
114 } while (0)
115#define read_unlock_bh(lock) _raw_read_unlock_bh(lock)
116
117#define write_unlock_irqrestore(lock, flags) \
118 do { \
119 typecheck(unsigned long, flags); \
120 _raw_write_unlock_irqrestore(lock, flags); \
121 } while (0)
122#define write_unlock_bh(lock) _raw_write_unlock_bh(lock)
123
124#define write_trylock_irqsave(lock, flags) \
125({ \
126 local_irq_save(flags); \
127 write_trylock(lock) ? \
128 1 : ({ local_irq_restore(flags); 0; }); \
129})
130
131#endif /* __LINUX_RWLOCK_H */
132