diff options
Diffstat (limited to 'include/linux/rwlock.h')
| -rw-r--r-- | include/linux/rwlock.h | 125 |
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 @@ +#ifndef __LINUX_RWLOCK_H +#define __LINUX_RWLOCK_H + +#ifndef __LINUX_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); +#define do_raw_read_lock_flags(lock, flags) do_raw_read_lock(lock) + extern int do_raw_read_trylock(rwlock_t *lock); + extern void do_raw_read_unlock(rwlock_t *lock); + extern void do_raw_write_lock(rwlock_t *lock); +#define do_raw_write_lock_flags(lock, flags) do_raw_write_lock(lock) + extern int do_raw_write_trylock(rwlock_t *lock); + extern void do_raw_write_unlock(rwlock_t *lock); +#else +# define do_raw_read_lock(rwlock) arch_read_lock(&(rwlock)->raw_lock) +# define do_raw_read_lock_flags(lock, flags) \ + arch_read_lock_flags(&(lock)->raw_lock, *(flags)) +# define do_raw_read_trylock(rwlock) arch_read_trylock(&(rwlock)->raw_lock) +# define do_raw_read_unlock(rwlock) arch_read_unlock(&(rwlock)->raw_lock) +# define do_raw_write_lock(rwlock) arch_write_lock(&(rwlock)->raw_lock) +# define do_raw_write_lock_flags(lock, flags) \ + arch_write_lock_flags(&(lock)->raw_lock, *(flags)) +# define do_raw_write_trylock(rwlock) arch_write_trylock(&(rwlock)->raw_lock) +# define do_raw_write_unlock(rwlock) arch_write_unlock(&(rwlock)->raw_lock) +#endif + +#define read_can_lock(rwlock) arch_read_can_lock(&(rwlock)->raw_lock) +#define write_can_lock(rwlock) arch_write_can_lock(&(rwlock)->raw_lock) + +/* + * 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) + +#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; }); \ +}) + +#endif /* __LINUX_RWLOCK_H */ |