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gerrit-public.fairphone.software / kernel / msm-4.9 / 80bea1897d7bc35e2b201847e12029a9d677cf12 / . / include / linux / percpu-rwsem.h
blob: 834c4e52cb2d1cab57ba33a3e87c025bc7e4a7cc [file] [log] [blame]
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]1#ifndef _LINUX_PERCPU_RWSEM_H
2#define _LINUX_PERCPU_RWSEM_H
3
Oleg Nesterov9390ef02012-12-17 16:01:36 -0800[diff] [blame]4#include <linux/atomic.h>
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]5#include <linux/rwsem.h>
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]6#include <linux/percpu.h>
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]7#include <linux/wait.h>
Oleg Nesterov8ebe3472012-12-17 16:01:38 -0800[diff] [blame]8#include <linux/lockdep.h>
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]9
10struct percpu_rw_semaphore {
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]11 unsigned int __percpu *fast_read_ctr;
Oleg Nesterov9390ef02012-12-17 16:01:36 -0800[diff] [blame]12 atomic_t write_ctr;
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]13 struct rw_semaphore rw_sem;
14 atomic_t slow_read_ctr;
15 wait_queue_head_t write_waitq;
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]16};
17
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]18extern void percpu_down_read(struct percpu_rw_semaphore *);
Oleg Nesterov9287f692015-07-21 17:45:57 +0200[diff] [blame]19extern int percpu_down_read_trylock(struct percpu_rw_semaphore *);
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]20extern void percpu_up_read(struct percpu_rw_semaphore *);
Mikulas Patocka5c1eabe2012-10-22 19:37:47 -0400[diff] [blame]21
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]22extern void percpu_down_write(struct percpu_rw_semaphore *);
23extern void percpu_up_write(struct percpu_rw_semaphore *);
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]24
Oleg Nesterov8ebe3472012-12-17 16:01:38 -0800[diff] [blame]25extern int __percpu_init_rwsem(struct percpu_rw_semaphore *,
26 const char *, struct lock_class_key *);
Oleg Nesterova1fd3e22012-12-17 16:01:32 -0800[diff] [blame]27extern void percpu_free_rwsem(struct percpu_rw_semaphore *);
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]28
Oleg Nesterov8ebe3472012-12-17 16:01:38 -0800[diff] [blame]29#define percpu_init_rwsem(brw) \
30({ \
31 static struct lock_class_key rwsem_key; \
32 __percpu_init_rwsem(brw, #brw, &rwsem_key); \
33})
34
Oleg Nesterov55cc156502015-07-21 20:26:44 +0200[diff] [blame]35
36#define percpu_rwsem_is_held(sem) lockdep_is_held(&(sem)->rw_sem)
37
38static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem,
39 bool read, unsigned long ip)
40{
41 lock_release(&sem->rw_sem.dep_map, 1, ip);
42#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
43 if (!read)
44 sem->rw_sem.owner = NULL;
45#endif
46}
47
48static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem,
49 bool read, unsigned long ip)
50{
51 lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip);
52}
53
Mikulas Patocka62ac6652012-09-26 07:46:43 +0200[diff] [blame]54#endif