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-rw-r--r--include/linux/rwlock.h125
1 files changed, 125 insertions, 0 deletions
diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
new file mode 100644
index 000000000000..71e0b00b6f2c
--- /dev/null
+++ b/include/linux/rwlock.h
@@ -0,0 +1,125 @@
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);
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);
36 extern void do_raw_write_lock(rwlock_t *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);
40#else
41# define do_raw_read_lock(rwlock) arch_read_lock(&(rwlock)->raw_lock)
42# define do_raw_read_lock_flags(lock, flags) \
43 arch_read_lock_flags(&(lock)->raw_lock, *(flags))
44# define do_raw_read_trylock(rwlock) arch_read_trylock(&(rwlock)->raw_lock)
45# define do_raw_read_unlock(rwlock) arch_read_unlock(&(rwlock)->raw_lock)
46# define do_raw_write_lock(rwlock) arch_write_lock(&(rwlock)->raw_lock)
47# define do_raw_write_lock_flags(lock, flags) \
48 arch_write_lock_flags(&(lock)->raw_lock, *(flags))
49# define do_raw_write_trylock(rwlock) arch_write_trylock(&(rwlock)->raw_lock)
50# define do_raw_write_unlock(rwlock) arch_write_unlock(&(rwlock)->raw_lock)
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 */