original_kernel/kernel/locking/mutex.h

55 lines
1.5 KiB
C

/*
* Mutexes: blocking mutual exclusion locks
*
* started by Ingo Molnar:
*
* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*
* This file contains mutex debugging related internal prototypes, for the
* !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs:
*/
#define spin_lock_mutex(lock, flags) \
do { spin_lock(lock); (void)(flags); } while (0)
#define spin_unlock_mutex(lock, flags) \
do { spin_unlock(lock); (void)(flags); } while (0)
#define mutex_remove_waiter(lock, waiter, task) \
__list_del((waiter)->list.prev, (waiter)->list.next)
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
/*
* The mutex owner can get read and written to locklessly.
* We should use WRITE_ONCE when writing the owner value to
* avoid store tearing, otherwise, a thread could potentially
* read a partially written and incomplete owner value.
*/
static inline void mutex_set_owner(struct mutex *lock)
{
WRITE_ONCE(lock->owner, current);
}
static inline void mutex_clear_owner(struct mutex *lock)
{
WRITE_ONCE(lock->owner, NULL);
}
#else
static inline void mutex_set_owner(struct mutex *lock)
{
}
static inline void mutex_clear_owner(struct mutex *lock)
{
}
#endif
#define debug_mutex_wake_waiter(lock, waiter) do { } while (0)
#define debug_mutex_free_waiter(waiter) do { } while (0)
#define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0)
#define debug_mutex_unlock(lock) do { } while (0)
#define debug_mutex_init(lock, name, key) do { } while (0)
static inline void
debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
}