Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[linux-2.6-microblaze.git] / include / linux / rwlock.h
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)                                      \
21 do {                                                            \
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 */