1 #ifndef __LINUX_RWLOCK_H 2 #define __LINUX_RWLOCK_H 3 4 #ifndef __LINUX_INSIDE_SPINLOCK_H 5 # error "Please do not 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 extern int do_raw_read_trylock(rwlock_t *lock); 34 extern void do_raw_read_unlock(rwlock_t *lock) __releases(lock); 35 extern void do_raw_write_lock(rwlock_t *lock) __acquires(lock); 36 extern int do_raw_write_trylock(rwlock_t *lock); 37 extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock); 38 #else 39 # define do_raw_read_lock(rwlock) do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0) 40 # define do_raw_read_trylock(rwlock) arch_read_trylock(&(rwlock)->raw_lock) 41 # define do_raw_read_unlock(rwlock) do {arch_read_unlock(&(rwlock)->raw_lock); __release(lock); } while (0) 42 # define do_raw_write_lock(rwlock) do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0) 43 # define do_raw_write_trylock(rwlock) arch_write_trylock(&(rwlock)->raw_lock) 44 # define do_raw_write_unlock(rwlock) do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0) 45 #endif 46 47 /* 48 * Define the various rw_lock methods. Note we define these 49 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various 50 * methods are defined as nops in the case they are not required. 51 */ 52 #define read_trylock(lock) __cond_lock(lock, _raw_read_trylock(lock)) 53 #define write_trylock(lock) __cond_lock(lock, _raw_write_trylock(lock)) 54 55 #define write_lock(lock) _raw_write_lock(lock) 56 #define read_lock(lock) _raw_read_lock(lock) 57 58 #ifdef CONFIG_DEBUG_LOCK_ALLOC 59 #define write_lock_nested(lock, subclass) _raw_write_lock_nested(lock, subclass) 60 #else 61 #define write_lock_nested(lock, subclass) _raw_write_lock(lock) 62 #endif 63 64 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) 65 66 #define read_lock_irqsave(lock, flags) \ 67 do { \ 68 typecheck(unsigned long, flags); \ 69 flags = _raw_read_lock_irqsave(lock); \ 70 } while (0) 71 #define write_lock_irqsave(lock, flags) \ 72 do { \ 73 typecheck(unsigned long, flags); \ 74 flags = _raw_write_lock_irqsave(lock); \ 75 } while (0) 76 77 #else 78 79 #define read_lock_irqsave(lock, flags) \ 80 do { \ 81 typecheck(unsigned long, flags); \ 82 _raw_read_lock_irqsave(lock, flags); \ 83 } while (0) 84 #define write_lock_irqsave(lock, flags) \ 85 do { \ 86 typecheck(unsigned long, flags); \ 87 _raw_write_lock_irqsave(lock, flags); \ 88 } while (0) 89 90 #endif 91 92 #define read_lock_irq(lock) _raw_read_lock_irq(lock) 93 #define read_lock_bh(lock) _raw_read_lock_bh(lock) 94 #define write_lock_irq(lock) _raw_write_lock_irq(lock) 95 #define write_lock_bh(lock) _raw_write_lock_bh(lock) 96 #define read_unlock(lock) _raw_read_unlock(lock) 97 #define write_unlock(lock) _raw_write_unlock(lock) 98 #define read_unlock_irq(lock) _raw_read_unlock_irq(lock) 99 #define write_unlock_irq(lock) _raw_write_unlock_irq(lock) 100 101 #define read_unlock_irqrestore(lock, flags) \ 102 do { \ 103 typecheck(unsigned long, flags); \ 104 _raw_read_unlock_irqrestore(lock, flags); \ 105 } while (0) 106 #define read_unlock_bh(lock) _raw_read_unlock_bh(lock) 107 108 #define write_unlock_irqrestore(lock, flags) \ 109 do { \ 110 typecheck(unsigned long, flags); \ 111 _raw_write_unlock_irqrestore(lock, flags); \ 112 } while (0) 113 #define write_unlock_bh(lock) _raw_write_unlock_bh(lock) 114 115 #define write_trylock_irqsave(lock, flags) \ 116 ({ \ 117 local_irq_save(flags); \ 118 write_trylock(lock) ? \ 119 1 : ({ local_irq_restore(flags); 0; }); \ 120 }) 121 122 #ifdef arch_rwlock_is_contended 123 #define rwlock_is_contended(lock) \ 124 arch_rwlock_is_contended(&(lock)->raw_lock) 125 #else 126 #define rwlock_is_contended(lock) ((void)(lock), 0) 127 #endif /* arch_rwlock_is_contended */ 128 129 #endif /* __LINUX_RWLOCK_H */ 130