Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright (c) 2008 Intel Corporation
|
|
* Author: Matthew Wilcox <willy@linux.intel.com>
|
|
*
|
|
* Please see kernel/locking/semaphore.c for documentation of these functions
|
|
*/
|
|
#ifndef __LINUX_SEMAPHORE_H
|
|
#define __LINUX_SEMAPHORE_H
|
|
|
|
#include <linux/list.h>
|
|
#include <linux/spinlock.h>
|
|
|
|
/* Please don't access any members of this structure directly */
|
|
struct semaphore {
|
|
raw_spinlock_t lock;
|
|
unsigned int count;
|
|
struct list_head wait_list;
|
|
|
|
#ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
|
|
unsigned long last_holder;
|
|
#endif
|
|
};
|
|
|
|
#ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
|
|
#define __LAST_HOLDER_SEMAPHORE_INITIALIZER \
|
|
, .last_holder = 0UL
|
|
#else
|
|
#define __LAST_HOLDER_SEMAPHORE_INITIALIZER
|
|
#endif
|
|
|
|
#define __SEMAPHORE_INITIALIZER(name, n) \
|
|
{ \
|
|
.lock = __RAW_SPIN_LOCK_UNLOCKED((name).lock), \
|
|
.count = n, \
|
|
.wait_list = LIST_HEAD_INIT((name).wait_list) \
|
|
__LAST_HOLDER_SEMAPHORE_INITIALIZER \
|
|
}
|
|
|
|
/*
|
|
* Unlike mutexes, binary semaphores do not have an owner, so up() can
|
|
* be called in a different thread from the one which called down().
|
|
* It is also safe to call down_trylock() and up() from interrupt
|
|
* context.
|
|
*/
|
|
#define DEFINE_SEMAPHORE(_name, _n) \
|
|
struct semaphore _name = __SEMAPHORE_INITIALIZER(_name, _n)
|
|
|
|
static inline void sema_init(struct semaphore *sem, int val)
|
|
{
|
|
static struct lock_class_key __key;
|
|
*sem = (struct semaphore) __SEMAPHORE_INITIALIZER(*sem, val);
|
|
lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0);
|
|
}
|
|
|
|
extern void down(struct semaphore *sem);
|
|
extern int __must_check down_interruptible(struct semaphore *sem);
|
|
extern int __must_check down_killable(struct semaphore *sem);
|
|
extern int __must_check down_trylock(struct semaphore *sem);
|
|
extern int __must_check down_timeout(struct semaphore *sem, long jiffies);
|
|
extern void up(struct semaphore *sem);
|
|
extern unsigned long sem_last_holder(struct semaphore *sem);
|
|
|
|
#endif /* __LINUX_SEMAPHORE_H */
|