1 #ifndef _LINUX_PERCPU_RWSEM_H
2 #define _LINUX_PERCPU_RWSEM_H
4 #include <linux/atomic.h>
5 #include <linux/rwsem.h>
6 #include <linux/percpu.h>
7 #include <linux/wait.h>
8 #include <linux/lockdep.h>
10 struct percpu_rw_semaphore
{
11 unsigned int __percpu
*fast_read_ctr
;
13 struct rw_semaphore rw_sem
;
14 atomic_t slow_read_ctr
;
15 wait_queue_head_t write_waitq
;
18 extern void percpu_down_read(struct percpu_rw_semaphore
*);
19 extern int percpu_down_read_trylock(struct percpu_rw_semaphore
*);
20 extern void percpu_up_read(struct percpu_rw_semaphore
*);
22 extern void percpu_down_write(struct percpu_rw_semaphore
*);
23 extern void percpu_up_write(struct percpu_rw_semaphore
*);
25 extern int __percpu_init_rwsem(struct percpu_rw_semaphore
*,
26 const char *, struct lock_class_key
*);
27 extern void percpu_free_rwsem(struct percpu_rw_semaphore
*);
29 #define percpu_init_rwsem(brw) \
31 static struct lock_class_key rwsem_key; \
32 __percpu_init_rwsem(brw, #brw, &rwsem_key); \