diff options
Diffstat (limited to 'include/linux/mutex_types.h')
-rw-r--r-- | include/linux/mutex_types.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/include/linux/mutex_types.h b/include/linux/mutex_types.h new file mode 100644 index 000000000000..fdf7f515fde8 --- /dev/null +++ b/include/linux/mutex_types.h @@ -0,0 +1,71 @@ +/* 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) + */ +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 list_head wait_list; +#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> + +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 */ |