Contributors: 12
Author Tokens Token Proportion Commits Commit Proportion
Linus Torvalds 53 33.97% 3 20.00%
Harvey Harrison 35 22.44% 1 6.67%
Ingo Molnar 16 10.26% 1 6.67%
Christoph Hellwig 13 8.33% 1 6.67%
Michal Hocko 11 7.05% 1 6.67%
Kirill V Tkhai 11 7.05% 1 6.67%
Rik Van Riel 8 5.13% 1 6.67%
Thomas Gleixner 3 1.92% 2 13.33%
Américo Wang 2 1.28% 1 6.67%
Peter Zijlstra 2 1.28% 1 6.67%
Michael Hayes 1 0.64% 1 6.67%
Greg Kroah-Hartman 1 0.64% 1 6.67%
Total 156 15 


/* SPDX-License-Identifier: GPL-2.0 */
/* rwsem-spinlock.h: fallback C implementation
 *
 * Copyright (c) 2001   David Howells (dhowells@redhat.com).
 * - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de>
 * - Derived also from comments by Linus
 */

#ifndef _LINUX_RWSEM_SPINLOCK_H
#define _LINUX_RWSEM_SPINLOCK_H

#ifndef _LINUX_RWSEM_H
#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead"
#endif

#ifdef __KERNEL__
/*
 * the rw-semaphore definition
 * - if count is 0 then there are no active readers or writers
 * - if count is +ve then that is the number of active readers
 * - if count is -1 then there is one active writer
 * - if wait_list is not empty, then there are processes waiting for the semaphore
 */
struct rw_semaphore {
	__s32			count;
	raw_spinlock_t		wait_lock;
	struct list_head	wait_list;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map dep_map;
#endif
};

#define RWSEM_UNLOCKED_VALUE		0x00000000

extern void __down_read(struct rw_semaphore *sem);
extern int __must_check __down_read_killable(struct rw_semaphore *sem);
extern int __down_read_trylock(struct rw_semaphore *sem);
extern void __down_write(struct rw_semaphore *sem);
extern int __must_check __down_write_killable(struct rw_semaphore *sem);
extern int __down_write_trylock(struct rw_semaphore *sem);
extern void __up_read(struct rw_semaphore *sem);
extern void __up_write(struct rw_semaphore *sem);
extern void __downgrade_write(struct rw_semaphore *sem);
extern int rwsem_is_locked(struct rw_semaphore *sem);

#endif /* __KERNEL__ */
#endif /* _LINUX_RWSEM_SPINLOCK_H */