|  | // SPDX-License-Identifier: GPL-2.0 | 
|  | #include "util.h" | 
|  | #include "rwsem.h" | 
|  |  | 
|  | int init_rwsem(struct rw_semaphore *sem) | 
|  | { | 
|  | return pthread_rwlock_init(&sem->lock, NULL); | 
|  | } | 
|  |  | 
|  | int exit_rwsem(struct rw_semaphore *sem) | 
|  | { | 
|  | return pthread_rwlock_destroy(&sem->lock); | 
|  | } | 
|  |  | 
|  | int down_read(struct rw_semaphore *sem) | 
|  | { | 
|  | return perf_singlethreaded ? 0 : pthread_rwlock_rdlock(&sem->lock); | 
|  | } | 
|  |  | 
|  | int up_read(struct rw_semaphore *sem) | 
|  | { | 
|  | return perf_singlethreaded ? 0 : pthread_rwlock_unlock(&sem->lock); | 
|  | } | 
|  |  | 
|  | int down_write(struct rw_semaphore *sem) | 
|  | { | 
|  | return perf_singlethreaded ? 0 : pthread_rwlock_wrlock(&sem->lock); | 
|  | } | 
|  |  | 
|  | int up_write(struct rw_semaphore *sem) | 
|  | { | 
|  | return perf_singlethreaded ? 0 : pthread_rwlock_unlock(&sem->lock); | 
|  | } |