[linux-2.6-block.git] / include / linux / freezer.h

/* SPDX-License-Identifier: GPL-2.0 */
/* Freezer declarations */

#ifndef FREEZER_H_INCLUDED
#define FREEZER_H_INCLUDED

#include <linux/debug_locks.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/atomic.h>
#include <linux/jump_label.h>

#ifdef CONFIG_FREEZER
DECLARE_STATIC_KEY_FALSE(freezer_active);

extern bool pm_freezing;		/* PM freezing in effect */
extern bool pm_nosig_freezing;		/* PM nosig freezing in effect */

/*
 * Timeout for stopping processes
 */
extern unsigned int freeze_timeout_msecs;

/*
 * Check if a process has been frozen
 */
extern bool frozen(struct task_struct *p);

extern bool freezing_slow_path(struct task_struct *p);

/*
 * Check if there is a request to freeze a process
 */
static inline bool freezing(struct task_struct *p)
{
	if (static_branch_unlikely(&freezer_active))
		return freezing_slow_path(p);

	return false;
}

/* Takes and releases task alloc lock using task_lock() */
extern void __thaw_task(struct task_struct *t);

extern bool __refrigerator(bool check_kthr_stop);
extern int freeze_processes(void);
extern int freeze_kernel_threads(void);
extern void thaw_processes(void);
extern void thaw_kernel_threads(void);

static inline bool try_to_freeze(void)
{
	might_sleep();
	if (likely(!freezing(current)))
		return false;
	if (!(current->flags & PF_NOFREEZE))
		debug_check_no_locks_held();
	return __refrigerator(false);
}

extern bool freeze_task(struct task_struct *p);
extern bool set_freezable(void);

#ifdef CONFIG_CGROUP_FREEZER
extern bool cgroup_freezing(struct task_struct *task);
#else /* !CONFIG_CGROUP_FREEZER */
static inline bool cgroup_freezing(struct task_struct *task)
{
	return false;
}
#endif /* !CONFIG_CGROUP_FREEZER */

#else /* !CONFIG_FREEZER */
static inline bool frozen(struct task_struct *p) { return false; }
static inline bool freezing(struct task_struct *p) { return false; }
static inline void __thaw_task(struct task_struct *t) {}

static inline bool __refrigerator(bool check_kthr_stop) { return false; }
static inline int freeze_processes(void) { return -ENOSYS; }
static inline int freeze_kernel_threads(void) { return -ENOSYS; }
static inline void thaw_processes(void) {}
static inline void thaw_kernel_threads(void) {}

static inline bool try_to_freeze(void) { return false; }

static inline void set_freezable(void) {}

#endif /* !CONFIG_FREEZER */

#endif	/* FREEZER_H_INCLUDED */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
7dfb7103 NC	2	/* Freezer declarations */
7dfb7103 NC	3
83144186 RW	4	#ifndef FREEZER_H_INCLUDED
	5	#define FREEZER_H_INCLUDED
	6
0f9548ca	7	#include <linux/debug_locks.h>
5c543eff	8	#include <linux/sched.h>
e42837bc	9	#include <linux/wait.h>
a3201227	10	#include <linux/atomic.h>
f5d39b02	11	#include <linux/jump_label.h>
5c543eff	12
8174f150	13	#ifdef CONFIG_FREEZER
f5d39b02 PZ	14	DECLARE_STATIC_KEY_FALSE(freezer_active);
f5d39b02 PZ	15
a3201227 TH	16	extern bool pm_freezing; /* PM freezing in effect */
	17	extern bool pm_nosig_freezing; /* PM nosig freezing in effect */
	18
957d1282 LF	19	/*
	20	* Timeout for stopping processes
	21	*/
	22	extern unsigned int freeze_timeout_msecs;
	23
7dfb7103 NC	24	/*
	25	* Check if a process has been frozen
	26	*/
f5d39b02	27	extern bool frozen(struct task_struct *p);
7dfb7103	28
a3201227	29	extern bool freezing_slow_path(struct task_struct *p);
7dfb7103 NC	30
7dfb7103 NC	31	/*
a3201227	32	* Check if there is a request to freeze a process
7dfb7103	33	*/
a3201227	34	static inline bool freezing(struct task_struct *p)
7dfb7103	35	{
f5d39b02 PZ	36	if (static_branch_unlikely(&freezer_active))
	37	return freezing_slow_path(p);
	38
	39	return false;
7dfb7103 NC	40	}
7dfb7103 NC	41
dc52ddc0	42	/* Takes and releases task alloc lock using task_lock() */
a5be2d0d	43	extern void __thaw_task(struct task_struct *t);
7dfb7103	44
8a32c441	45	extern bool __refrigerator(bool check_kthr_stop);
7dfb7103	46	extern int freeze_processes(void);
2aede851	47	extern int freeze_kernel_threads(void);
a9b6f562	48	extern void thaw_processes(void);
181e9bde	49	extern void thaw_kernel_threads(void);
7dfb7103	50
f5d39b02	51	static inline bool try_to_freeze(void)
7dfb7103	52	{
a0acae0e TH	53	might_sleep();
	54	if (likely(!freezing(current)))
	55	return false;
0f9548ca MSB	56	if (!(current->flags & PF_NOFREEZE))
0f9548ca MSB	57	debug_check_no_locks_held();
f5d39b02	58	return __refrigerator(false);
416ad3c9 CC	59	}
416ad3c9 CC	60
839e3407	61	extern bool freeze_task(struct task_struct *p);
34b087e4	62	extern bool set_freezable(void);
8174f150	63
dc52ddc0	64	#ifdef CONFIG_CGROUP_FREEZER
22b4e111	65	extern bool cgroup_freezing(struct task_struct *task);
dc52ddc0	66	#else /* !CONFIG_CGROUP_FREEZER */
22b4e111	67	static inline bool cgroup_freezing(struct task_struct *task)
5a7aadfe	68	{
22b4e111	69	return false;
5a7aadfe	70	}
dc52ddc0 MH	71	#endif /* !CONFIG_CGROUP_FREEZER */
dc52ddc0 MH	72
8174f150	73	#else /* !CONFIG_FREEZER */
948246f7	74	static inline bool frozen(struct task_struct *p) { return false; }
a3201227	75	static inline bool freezing(struct task_struct *p) { return false; }
62c9ea6b	76	static inline void __thaw_task(struct task_struct *t) {}
7dfb7103	77
8a32c441	78	static inline bool __refrigerator(bool check_kthr_stop) { return false; }
2aede851 RW	79	static inline int freeze_processes(void) { return -ENOSYS; }
2aede851 RW	80	static inline int freeze_kernel_threads(void) { return -ENOSYS; }
7dfb7103	81	static inline void thaw_processes(void) {}
181e9bde	82	static inline void thaw_kernel_threads(void) {}
7dfb7103	83
a0acae0e	84	static inline bool try_to_freeze(void) { return false; }
7dfb7103	85
83144186	86	static inline void set_freezable(void) {}
e42837bc	87
8174f150	88	#endif /* !CONFIG_FREEZER */
83144186 RW	89
83144186 RW	90	#endif /* FREEZER_H_INCLUDED */