Viewing file:  rwlock.h (4.15 KB) -rw-r--r--
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#ifndef __LINUX_RWLOCK_H
#define __LINUX_RWLOCK_H
#ifndef __LINUX_INSIDE_SPINLOCK_H
# error "please don't include this file directly"
#endif
/*
* rwlock related methods
*
* split out from spinlock.h
*
* portions Copyright 2005, Red Hat, Inc., Ingo Molnar
* Released under the General Public License (GPL).
*/
#ifdef CONFIG_DEBUG_SPINLOCK
extern void __rwlock_init(rwlock_t *lock, const char *name,
struct lock_class_key *key);
# define rwlock_init(lock) \
do { \
static struct lock_class_key __key; \
\
__rwlock_init((lock), #lock, &__key); \
} while (0)
#else
# define rwlock_init(lock) \
do { *(lock) = __RW_LOCK_UNLOCKED(lock); } while (0)
#endif
#ifdef CONFIG_DEBUG_SPINLOCK
extern void do_raw_read_lock(rwlock_t *lock) __acquires(lock);
extern int do_raw_read_trylock(rwlock_t *lock);
extern void do_raw_read_unlock(rwlock_t *lock) __releases(lock);
extern void do_raw_write_lock(rwlock_t *lock) __acquires(lock);
extern int do_raw_write_trylock(rwlock_t *lock);
extern void do_raw_write_unlock(rwlock_t *lock) __releases(lock);
#else
# define do_raw_read_lock(rwlock) do {__acquire(lock); arch_read_lock(&(rwlock)->raw_lock); } while (0)
# define do_raw_read_trylock(rwlock) arch_read_trylock(&(rwlock)->raw_lock)
# define do_raw_read_unlock(rwlock) do {arch_read_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
# define do_raw_write_lock(rwlock) do {__acquire(lock); arch_write_lock(&(rwlock)->raw_lock); } while (0)
# define do_raw_write_trylock(rwlock) arch_write_trylock(&(rwlock)->raw_lock)
# define do_raw_write_unlock(rwlock) do {arch_write_unlock(&(rwlock)->raw_lock); __release(lock); } while (0)
#endif
/*
* Define the various rw_lock methods. Note we define these
* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
* methods are defined as nops in the case they are not required.
*/
#define read_trylock(lock) __cond_lock(lock, _raw_read_trylock(lock))
#define write_trylock(lock) __cond_lock(lock, _raw_write_trylock(lock))
#define write_lock(lock) _raw_write_lock(lock)
#define read_lock(lock) _raw_read_lock(lock)
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define write_lock_nested(lock, subclass) _raw_write_lock_nested(lock, subclass)
#else
#define write_lock_nested(lock, subclass) _raw_write_lock(lock)
#endif
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
#define read_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
flags = _raw_read_lock_irqsave(lock); \
} while (0)
#define write_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
flags = _raw_write_lock_irqsave(lock); \
} while (0)
#else
#define read_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
_raw_read_lock_irqsave(lock, flags); \
} while (0)
#define write_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
_raw_write_lock_irqsave(lock, flags); \
} while (0)
#endif
#define read_lock_irq(lock) _raw_read_lock_irq(lock)
#define read_lock_bh(lock) _raw_read_lock_bh(lock)
#define write_lock_irq(lock) _raw_write_lock_irq(lock)
#define write_lock_bh(lock) _raw_write_lock_bh(lock)
#define read_unlock(lock) _raw_read_unlock(lock)
#define write_unlock(lock) _raw_write_unlock(lock)
#define read_unlock_irq(lock) _raw_read_unlock_irq(lock)
#define write_unlock_irq(lock) _raw_write_unlock_irq(lock)
#define read_unlock_irqrestore(lock, flags) \
do { \
typecheck(unsigned long, flags); \
_raw_read_unlock_irqrestore(lock, flags); \
} while (0)
#define read_unlock_bh(lock) _raw_read_unlock_bh(lock)
#define write_unlock_irqrestore(lock, flags) \
do { \
typecheck(unsigned long, flags); \
_raw_write_unlock_irqrestore(lock, flags); \
} while (0)
#define write_unlock_bh(lock) _raw_write_unlock_bh(lock)
#define write_trylock_irqsave(lock, flags) \
({ \
local_irq_save(flags); \
write_trylock(lock) ? \
1 : ({ local_irq_restore(flags); 0; }); \
})
#ifdef arch_rwlock_is_contended
#define rwlock_is_contended(lock) \
arch_rwlock_is_contended(&(lock)->raw_lock)
#else
#define rwlock_is_contended(lock) ((void)(lock), 0)
#endif /* arch_rwlock_is_contended */
#endif /* __LINUX_RWLOCK_H */
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