bcachefs-tools/include/linux/percpu-rwsem.h
Kent Overstreet 0aaa849412 use a mutex for percpu rwsemaphores
bcachefs is using a percpu rwsem to protect percpu data structures, and
in userspace we don't have real percpu data structures - so we need to
guard all access to them with a mutex.
2019-03-08 14:41:57 -05:00

54 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PERCPU_RWSEM_H
#define _LINUX_PERCPU_RWSEM_H
#include <pthread.h>
#include <linux/preempt.h>
struct percpu_rw_semaphore {
pthread_mutex_t lock;
};
static inline void percpu_down_read_preempt_disable(struct percpu_rw_semaphore *sem)
{
pthread_mutex_lock(&sem->lock);
}
static inline void percpu_down_read(struct percpu_rw_semaphore *sem)
{
pthread_mutex_lock(&sem->lock);
}
static inline void percpu_up_read_preempt_enable(struct percpu_rw_semaphore *sem)
{
pthread_mutex_unlock(&sem->lock);
}
static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
{
pthread_mutex_unlock(&sem->lock);
}
static inline void percpu_down_write(struct percpu_rw_semaphore *sem)
{
pthread_mutex_lock(&sem->lock);
}
static inline void percpu_up_write(struct percpu_rw_semaphore *sem)
{
pthread_mutex_unlock(&sem->lock);
}
static inline void percpu_free_rwsem(struct percpu_rw_semaphore *sem) {}
static inline int percpu_init_rwsem(struct percpu_rw_semaphore *sem)
{
pthread_mutex_init(&sem->lock, NULL);
return 0;
}
#define percpu_rwsem_assert_held(sem) do {} while (0)
#endif