Contributors: 14
Author Tokens Token Proportion Commits Commit Proportion
Ingo Molnar 30 27.27% 2 10.53%
Thomas Gleixner 21 19.09% 2 10.53%
Kent Overstreet 19 17.27% 1 5.26%
Peter Zijlstra 10 9.09% 4 21.05%
Marco Elver 10 9.09% 1 5.26%
Waiman Long 5 4.55% 1 5.26%
Jason Low 4 3.64% 1 5.26%
Matthew Wilcox 3 2.73% 1 5.26%
Linus Torvalds (pre-git) 2 1.82% 1 5.26%
Heiko Carstens 2 1.82% 1 5.26%
Arun Sharma 1 0.91% 1 5.26%
Greg Kroah-Hartman 1 0.91% 1 5.26%
Tim Chen 1 0.91% 1 5.26%
Matti Linnanvuori 1 0.91% 1 5.26%
Total 110 19 


/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_MUTEX_TYPES_H
#define __LINUX_MUTEX_TYPES_H

#include <linux/atomic.h>
#include <linux/lockdep_types.h>
#include <linux/osq_lock.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>

#ifndef CONFIG_PREEMPT_RT

/*
 * Simple, straightforward mutexes with strict semantics:
 *
 * - only one task can hold the mutex at a time
 * - only the owner can unlock the mutex
 * - multiple unlocks are not permitted
 * - recursive locking is not permitted
 * - a mutex object must be initialized via the API
 * - a mutex object must not be initialized via memset or copying
 * - task may not exit with mutex held
 * - memory areas where held locks reside must not be freed
 * - held mutexes must not be reinitialized
 * - mutexes may not be used in hardware or software interrupt
 *   contexts such as tasklets and timers
 *
 * These semantics are fully enforced when DEBUG_MUTEXES is
 * enabled. Furthermore, besides enforcing the above rules, the mutex
 * debugging code also implements a number of additional features
 * that make lock debugging easier and faster:
 *
 * - uses symbolic names of mutexes, whenever they are printed in debug output
 * - point-of-acquire tracking, symbolic lookup of function names
 * - list of all locks held in the system, printout of them
 * - owner tracking
 * - detects self-recursing locks and prints out all relevant info
 * - detects multi-task circular deadlocks and prints out all affected
 *   locks and tasks (and only those tasks)
 */
context_lock_struct(mutex) {
	atomic_long_t		owner;
	raw_spinlock_t		wait_lock;
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
	struct optimistic_spin_queue osq; /* Spinner MCS lock */
#endif
	struct mutex_waiter	*first_waiter __guarded_by(&wait_lock);
#ifdef CONFIG_DEBUG_MUTEXES
	void			*magic;
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
};

#else /* !CONFIG_PREEMPT_RT */
/*
 * Preempt-RT variant based on rtmutexes.
 */
#include <linux/rtmutex.h>

context_lock_struct(mutex) {
	struct rt_mutex_base	rtmutex;
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	dep_map;
#endif
};

#endif /* CONFIG_PREEMPT_RT */

#endif /* __LINUX_MUTEX_TYPES_H */