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 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 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) 59 60 #define read_lock_irqsave(lock, flags) \ 61 do { \ 62 typecheck(unsigned long, flags); \ 63 flags = _raw_read_lock_irqsave(lock); \ 64 } while (0) 65 #define write_lock_irqsave(lock, flags) \ 66 do { \ 67 typecheck(unsigned long, flags); \ 68 flags = _raw_write_lock_irqsave(lock); \ 69 } while (0) 70 71 #else 72 73 #define read_lock_irqsave(lock, flags) \ 74 do { \ 75 typecheck(unsigned long, flags); \ 76 _raw_read_lock_irqsave(lock, flags); \ 77 } while (0) 78 #define write_lock_irqsave(lock, flags) \ 79 do { \ 80 typecheck(unsigned long, flags); \ 81 _raw_write_lock_irqsave(lock, flags); \ 82 } while (0) 83 84 #endif 85 86 #define read_lock_irq(lock) _raw_read_lock_irq(lock) 87 #define read_lock_bh(lock) _raw_read_lock_bh(lock) 88 #define write_lock_irq(lock) _raw_write_lock_irq(lock) 89 #define write_lock_bh(lock) _raw_write_lock_bh(lock) 90 #define read_unlock(lock) _raw_read_unlock(lock) 91 #define write_unlock(lock) _raw_write_unlock(lock) 92 #define read_unlock_irq(lock) _raw_read_unlock_irq(lock) 93 #define write_unlock_irq(lock) _raw_write_unlock_irq(lock) 94 95 #define read_unlock_irqrestore(lock, flags) \ 96 do { \ 97 typecheck(unsigned long, flags); \ 98 _raw_read_unlock_irqrestore(lock, flags); \ 99 } while (0) 100 #define read_unlock_bh(lock) _raw_read_unlock_bh(lock) 101 102 #define write_unlock_irqrestore(lock, flags) \ 103 do { \ 104 typecheck(unsigned long, flags); \ 105 _raw_write_unlock_irqrestore(lock, flags); \ 106 } while (0) 107 #define write_unlock_bh(lock) _raw_write_unlock_bh(lock) 108 109 #define write_trylock_irqsave(lock, flags) \ 110 ({ \ 111 local_irq_save(flags); \ 112 write_trylock(lock) ? \ 113 1 : ({ local_irq_restore(flags); 0; }); \ 114 }) 115 116 #ifdef arch_rwlock_is_contended 117 #define rwlock_is_contended(lock) \ 118 arch_rwlock_is_contended(&(lock)->raw_lock) 119 #else 120 #define rwlock_is_contended(lock) ((void)(lock), 0) 121 #endif /* arch_rwlock_is_contended */ 122 123 #endif /* __LINUX_RWLOCK_H */ 124