diff options
Diffstat (limited to 'include/linux/mutex.h')
| -rw-r--r-- | include/linux/mutex.h | 109 |
1 files changed, 86 insertions, 23 deletions
diff --git a/include/linux/mutex.h b/include/linux/mutex.h index f1ac507fa20..42aa9b9ecd5 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -10,11 +10,14 @@ #ifndef __LINUX_MUTEX_H #define __LINUX_MUTEX_H +#include <asm/current.h> #include <linux/list.h> #include <linux/spinlock_types.h> #include <linux/linkage.h> - -#include <asm/atomic.h> +#include <linux/lockdep.h> +#include <linux/atomic.h> +#include <asm/processor.h> +#include <linux/osq_lock.h> /* * Simple, straightforward mutexes with strict semantics: @@ -28,7 +31,8 @@ * - 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 irq contexts + * - 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 @@ -48,13 +52,19 @@ struct mutex { atomic_t count; spinlock_t wait_lock; struct list_head wait_list; +#if defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_SMP) + struct task_struct *owner; +#endif +#ifdef CONFIG_MUTEX_SPIN_ON_OWNER + struct optimistic_spin_queue osq; /* Spinner MCS lock */ +#endif #ifdef CONFIG_DEBUG_MUTEXES - struct thread_info *owner; - struct list_head held_list; - unsigned long acquire_ip; const char *name; void *magic; #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif }; /* @@ -65,7 +75,6 @@ struct mutex_waiter { struct list_head list; struct task_struct *task; #ifdef CONFIG_DEBUG_MUTEXES - struct mutex *lock; void *magic; #endif }; @@ -74,47 +83,101 @@ struct mutex_waiter { # include <linux/mutex-debug.h> #else # define __DEBUG_MUTEX_INITIALIZER(lockname) -# define mutex_init(mutex) __mutex_init(mutex, NULL) -# define mutex_destroy(mutex) do { } while (0) -# define mutex_debug_show_all_locks() do { } while (0) -# define mutex_debug_show_held_locks(p) do { } while (0) -# define mutex_debug_check_no_locks_held(task) do { } while (0) -# define mutex_debug_check_no_locks_freed(from, len) do { } while (0) +/** + * mutex_init - initialize the mutex + * @mutex: the mutex to be initialized + * + * Initialize the mutex to unlocked state. + * + * It is not allowed to initialize an already locked mutex. + */ +# define mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + \ + __mutex_init((mutex), #mutex, &__key); \ +} while (0) +static inline void mutex_destroy(struct mutex *lock) {} +#endif + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ + , .dep_map = { .name = #lockname } +#else +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) #endif #define __MUTEX_INITIALIZER(lockname) \ { .count = ATOMIC_INIT(1) \ - , .wait_lock = SPIN_LOCK_UNLOCKED \ + , .wait_lock = __SPIN_LOCK_UNLOCKED(lockname.wait_lock) \ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ - __DEBUG_MUTEX_INITIALIZER(lockname) } + __DEBUG_MUTEX_INITIALIZER(lockname) \ + __DEP_MAP_MUTEX_INITIALIZER(lockname) } #define DEFINE_MUTEX(mutexname) \ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) -extern void fastcall __mutex_init(struct mutex *lock, const char *name); +extern void __mutex_init(struct mutex *lock, const char *name, + struct lock_class_key *key); -/*** +/** * mutex_is_locked - is the mutex locked * @lock: the mutex to be queried * * Returns 1 if the mutex is locked, 0 if unlocked. */ -static inline int fastcall mutex_is_locked(struct mutex *lock) +static inline int mutex_is_locked(struct mutex *lock) { return atomic_read(&lock->count) != 1; } /* - * See kernel/mutex.c for detailed documentation of these APIs. + * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/mutex-design.txt. */ -extern void fastcall mutex_lock(struct mutex *lock); -extern int fastcall mutex_lock_interruptible(struct mutex *lock); +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass); +extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock); + +extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock, + unsigned int subclass); +extern int __must_check mutex_lock_killable_nested(struct mutex *lock, + unsigned int subclass); + +#define mutex_lock(lock) mutex_lock_nested(lock, 0) +#define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0) +#define mutex_lock_killable(lock) mutex_lock_killable_nested(lock, 0) + +#define mutex_lock_nest_lock(lock, nest_lock) \ +do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \ + _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \ +} while (0) + +#else +extern void mutex_lock(struct mutex *lock); +extern int __must_check mutex_lock_interruptible(struct mutex *lock); +extern int __must_check mutex_lock_killable(struct mutex *lock); + +# define mutex_lock_nested(lock, subclass) mutex_lock(lock) +# define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock) +# define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock) +# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock) +#endif + /* * NOTE: mutex_trylock() follows the spin_trylock() convention, * not the down_trylock() convention! + * + * Returns 1 if the mutex has been acquired successfully, and 0 on contention. */ -extern int fastcall mutex_trylock(struct mutex *lock); -extern void fastcall mutex_unlock(struct mutex *lock); +extern int mutex_trylock(struct mutex *lock); +extern void mutex_unlock(struct mutex *lock); +extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); + +#ifndef arch_mutex_cpu_relax +# define arch_mutex_cpu_relax() cpu_relax() #endif + +#endif /* __LINUX_MUTEX_H */ |