1#ifndef _LINUX_PERCPU_RWSEM_H 2#define _LINUX_PERCPU_RWSEM_H 3 4#include <linux/atomic.h> 5#include <linux/rwsem.h> 6#include <linux/percpu.h> 7#include <linux/wait.h> 8#include <linux/rcu_sync.h> 9#include <linux/lockdep.h> 10 11struct percpu_rw_semaphore { 12 struct rcu_sync rss; 13 unsigned int __percpu *fast_read_ctr; 14 struct rw_semaphore rw_sem; 15 atomic_t slow_read_ctr; 16 wait_queue_head_t write_waitq; 17}; 18 19extern void percpu_down_read(struct percpu_rw_semaphore *); 20extern int percpu_down_read_trylock(struct percpu_rw_semaphore *); 21extern void percpu_up_read(struct percpu_rw_semaphore *); 22 23extern void percpu_down_write(struct percpu_rw_semaphore *); 24extern void percpu_up_write(struct percpu_rw_semaphore *); 25 26extern int __percpu_init_rwsem(struct percpu_rw_semaphore *, 27 const char *, struct lock_class_key *); 28extern void percpu_free_rwsem(struct percpu_rw_semaphore *); 29 30#define percpu_init_rwsem(brw) \ 31({ \ 32 static struct lock_class_key rwsem_key; \ 33 __percpu_init_rwsem(brw, #brw, &rwsem_key); \ 34}) 35 36 37#define percpu_rwsem_is_held(sem) lockdep_is_held(&(sem)->rw_sem) 38 39static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem, 40 bool read, unsigned long ip) 41{ 42 lock_release(&sem->rw_sem.dep_map, 1, ip); 43#ifdef CONFIG_RWSEM_SPIN_ON_OWNER 44 if (!read) 45 sem->rw_sem.owner = NULL; 46#endif 47} 48 49static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem, 50 bool read, unsigned long ip) 51{ 52 lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip); 53} 54 55#endif 56