diff options
Diffstat (limited to 'kernel/rwsem.c')
-rw-r--r-- | kernel/rwsem.c | 157 |
1 files changed, 0 insertions, 157 deletions
diff --git a/kernel/rwsem.c b/kernel/rwsem.c deleted file mode 100644 index cfff1435bdfb..000000000000 --- a/kernel/rwsem.c +++ /dev/null @@ -1,157 +0,0 @@ -/* kernel/rwsem.c: R/W semaphores, public implementation - * - * Written by David Howells (dhowells@redhat.com). - * Derived from asm-i386/semaphore.h - */ - -#include <linux/types.h> -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/export.h> -#include <linux/rwsem.h> - -#include <linux/atomic.h> - -/* - * lock for reading - */ -void __sched down_read(struct rw_semaphore *sem) -{ - might_sleep(); - rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_); - - LOCK_CONTENDED(sem, __down_read_trylock, __down_read); -} - -EXPORT_SYMBOL(down_read); - -/* - * trylock for reading -- returns 1 if successful, 0 if contention - */ -int down_read_trylock(struct rw_semaphore *sem) -{ - int ret = __down_read_trylock(sem); - - if (ret == 1) - rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_); - return ret; -} - -EXPORT_SYMBOL(down_read_trylock); - -/* - * lock for writing - */ -void __sched down_write(struct rw_semaphore *sem) -{ - might_sleep(); - rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); - - LOCK_CONTENDED(sem, __down_write_trylock, __down_write); -} - -EXPORT_SYMBOL(down_write); - -/* - * trylock for writing -- returns 1 if successful, 0 if contention - */ -int down_write_trylock(struct rw_semaphore *sem) -{ - int ret = __down_write_trylock(sem); - - if (ret == 1) - rwsem_acquire(&sem->dep_map, 0, 1, _RET_IP_); - return ret; -} - -EXPORT_SYMBOL(down_write_trylock); - -/* - * release a read lock - */ -void up_read(struct rw_semaphore *sem) -{ - rwsem_release(&sem->dep_map, 1, _RET_IP_); - - __up_read(sem); -} - -EXPORT_SYMBOL(up_read); - -/* - * release a write lock - */ -void up_write(struct rw_semaphore *sem) -{ - rwsem_release(&sem->dep_map, 1, _RET_IP_); - - __up_write(sem); -} - -EXPORT_SYMBOL(up_write); - -/* - * downgrade write lock to read lock - */ -void downgrade_write(struct rw_semaphore *sem) -{ - /* - * lockdep: a downgraded write will live on as a write - * dependency. - */ - __downgrade_write(sem); -} - -EXPORT_SYMBOL(downgrade_write); - -#ifdef CONFIG_DEBUG_LOCK_ALLOC - -void down_read_nested(struct rw_semaphore *sem, int subclass) -{ - might_sleep(); - rwsem_acquire_read(&sem->dep_map, subclass, 0, _RET_IP_); - - LOCK_CONTENDED(sem, __down_read_trylock, __down_read); -} - -EXPORT_SYMBOL(down_read_nested); - -void _down_write_nest_lock(struct rw_semaphore *sem, struct lockdep_map *nest) -{ - might_sleep(); - rwsem_acquire_nest(&sem->dep_map, 0, 0, nest, _RET_IP_); - - LOCK_CONTENDED(sem, __down_write_trylock, __down_write); -} - -EXPORT_SYMBOL(_down_write_nest_lock); - -void down_read_non_owner(struct rw_semaphore *sem) -{ - might_sleep(); - - __down_read(sem); -} - -EXPORT_SYMBOL(down_read_non_owner); - -void down_write_nested(struct rw_semaphore *sem, int subclass) -{ - might_sleep(); - rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_); - - LOCK_CONTENDED(sem, __down_write_trylock, __down_write); -} - -EXPORT_SYMBOL(down_write_nested); - -void up_read_non_owner(struct rw_semaphore *sem) -{ - __up_read(sem); -} - -EXPORT_SYMBOL(up_read_non_owner); - -#endif - - |