/* kernel/rwsem.c: R/W semaphores, public implementation * * Written by David Howells (dhowells@redhat.com). * Derived from asm-i386/semaphore.h */ #include #include #include #include #include #include #include "rwsem.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); rwsem_set_reader_owned(sem); } 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_); rwsem_set_reader_owned(sem); } 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); rwsem_set_owner(sem); } EXPORT_SYMBOL(down_write); /* * lock for writing */ int __sched down_write_killable(struct rw_semaphore *sem) { might_sleep(); rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_); if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) { rwsem_release(&sem->dep_map, 1, _RET_IP_); return -EINTR; } rwsem_set_owner(sem); return 0; } EXPORT_SYMBOL(down_write_killable); /* * 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_); rwsem_set_owner(sem); } 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_); rwsem_clear_owner(sem); __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. */ rwsem_set_reader_owned(sem); __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); rwsem_set_reader_owned(sem); } 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); rwsem_set_owner(sem); } 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); rwsem_set_owner(sem); } EXPORT_SYMBOL(down_write_nested); int __sched down_write_killable_nested(struct rw_semaphore *sem, int subclass) { might_sleep(); rwsem_acquire(&sem->dep_map, subclass, 0, _RET_IP_); if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) { rwsem_release(&sem->dep_map, 1, _RET_IP_); return -EINTR; } rwsem_set_owner(sem); return 0; } EXPORT_SYMBOL(down_write_killable_nested); void up_read_non_owner(struct rw_semaphore *sem) { __up_read(sem); } EXPORT_SYMBOL(up_read_non_owner); #endif 0159fee4b'>logplain -rw-r--r--ad1816a.h5514log plain -rw-r--r--ad1843.h1516log plain -rw-r--r--adau1373.h699log plain -rw-r--r--aess.h1668log plain -rw-r--r--ak4113.h11112log plain -rw-r--r--ak4114.h10424log plain -rw-r--r--ak4117.h9193log plain -rw-r--r--ak4531_codec.h3173log plain -rw-r--r--ak4641.h622log plain -rw-r--r--ak4xxx-adda.h3416log plain -rw-r--r--alc5623.h497log plain -rw-r--r--asequencer.h3670log plain -rw-r--r--asound.h1285log plain -rw-r--r--asoundef.h17098log plain -rw-r--r--atmel-abdac.h639log plain -rw-r--r--atmel-ac97c.h1342log plain -rw-r--r--compress_driver.h6772log plain -rw-r--r--control.h8704log plain -rw-r--r--core.h14380log plain -rw-r--r--cs35l33.h1034log plain -rw-r--r--cs35l34.h887log plain -rw-r--r--cs4231-regs.h8480log plain -rw-r--r--cs4271.h1417log plain -rw-r--r--cs42l52.h738log plain -rw-r--r--cs42l56.h1192log plain -rw-r--r--cs42l73.h507log plain -rw-r--r--cs8403.h8833log plain -rw-r--r--cs8427.h10649log plain -rw-r--r--da7213.h1178log plain -rw-r--r--da7218.h2681log plain -rw-r--r--da7219-aad.h2476log plain -rw-r--r--da7219.h1064log plain -rw-r--r--da9055.h914log plain -rw-r--r--designware_i2s.h2249log plain -rw-r--r--dmaengine_pcm.h6157log plain -rw-r--r--emu10k1.h91396log plain -rw-r--r--emu10k1_synth.h1382log plain -rw-r--r--emu8000.h4109log plain -rw-r--r--emu8000_reg.h10459log plain -rw-r--r--emux_legacy.h5503log plain -rw-r--r--emux_synth.h7649log plain -rw-r--r--es1688.h3618log plain -rw-r--r--gus.h20691log plain -rw-r--r--hda_chmap.h2621log plain -rw-r--r--hda_hwdep.h1412log plain -rw-r--r--hda_i915.h1645log plain -rw-r--r--hda_register.h9475log plain -rw-r--r--hda_regmap.h6714log plain -rw-r--r--hda_verbs.h17130log plain -rw-r--r--hdaudio.h18455log plain -rw-r--r--hdaudio_ext.h7119log plain -rw-r--r--hdmi-codec.h2290log plain -rw-r--r--hwdep.h2624log plain -rw-r--r--i2c.h3555log plain -rw-r--r--info.h7584log plain