git.sesse.net Git - bcachefs-tools-debian/blob - include/linux/percpu-rwsem.h

   1
   2 /* SPDX-License-Identifier: GPL-2.0 */
   3 #ifndef _LINUX_PERCPU_RWSEM_H
   4 #define _LINUX_PERCPU_RWSEM_H
   5
   6 #include <pthread.h>
   7 #include <linux/preempt.h>
   8
   9 struct percpu_rw_semaphore {
  10         pthread_rwlock_t        lock;
  11 };
  12
  13 #define DEFINE_STATIC_PERCPU_RWSEM(name)                                \
  14 static DEFINE_PER_CPU(unsigned int, __percpu_rwsem_rc_##name);          \
  15 static struct percpu_rw_semaphore name = {                              \
  16         .rss = __RCU_SYNC_INITIALIZER(name.rss, RCU_SCHED_SYNC),        \
  17         .read_count = &__percpu_rwsem_rc_##name,                        \
  18         .rw_sem = __RWSEM_INITIALIZER(name.rw_sem),                     \
  19         .writer = __RCUWAIT_INITIALIZER(name.writer),                   \
  20 }
  21
  22 extern int __percpu_down_read(struct percpu_rw_semaphore *, int);
  23 extern void __percpu_up_read(struct percpu_rw_semaphore *);
  24
  25 static inline void percpu_down_read_preempt_disable(struct percpu_rw_semaphore *sem)
  26 {
  27         pthread_rwlock_rdlock(&sem->lock);
  28         preempt_disable();
  29 }
  30
  31 static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
  32 {
  33         pthread_rwlock_rdlock(&sem->lock);
  34 }
  35
  36 static inline int percpu_down_read_trylock(struct percpu_rw_semaphore *sem)
  37 {
  38         return !pthread_rwlock_tryrdlock(&sem->lock);
  39 }
  40
  41 static inline void percpu_up_read_preempt_enable(struct percpu_rw_semaphore *sem)
  42 {
  43         preempt_enable();
  44         pthread_rwlock_unlock(&sem->lock);
  45 }
  46
  47 static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
  48 {
  49         pthread_rwlock_unlock(&sem->lock);
  50 }
  51
  52 static inline void percpu_down_write(struct percpu_rw_semaphore *sem)
  53 {
  54         pthread_rwlock_wrlock(&sem->lock);
  55 }
  56
  57 static inline void percpu_up_write(struct percpu_rw_semaphore *sem)
  58 {
  59         pthread_rwlock_unlock(&sem->lock);
  60 }
  61
  62 static inline void percpu_free_rwsem(struct percpu_rw_semaphore *sem) {}
  63
  64 static inline int percpu_init_rwsem(struct percpu_rw_semaphore *sem)
  65 {
  66         pthread_rwlock_init(&sem->lock, NULL);
  67         return 0;
  68 }
  69
  70 #define percpu_rwsem_assert_held(sem)           do {} while (0)
  71
  72 #endif