[linux-block.git] / include / linux / kthread.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KTHREAD_H
#define _LINUX_KTHREAD_H
/* Simple interface for creating and stopping kernel threads without mess. */
#include <linux/err.h>
#include <linux/sched.h>

struct mm_struct;

__printf(4, 5)
struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
					   void *data,
					   int node,
					   const char namefmt[], ...);

/**
 * kthread_create - create a kthread on the current node
 * @threadfn: the function to run in the thread
 * @data: data pointer for @threadfn()
 * @namefmt: printf-style format string for the thread name
 * @arg: arguments for @namefmt.
 *
 * This macro will create a kthread on the current node, leaving it in
 * the stopped state.  This is just a helper for kthread_create_on_node();
 * see the documentation there for more details.
 */
#define kthread_create(threadfn, data, namefmt, arg...) \
	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)


struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
					  void *data,
					  unsigned int cpu,
					  const char *namefmt);

void get_kthread_comm(char *buf, size_t buf_size, struct task_struct *tsk);
bool set_kthread_struct(struct task_struct *p);

void kthread_set_per_cpu(struct task_struct *k, int cpu);
bool kthread_is_per_cpu(struct task_struct *k);

/**
 * kthread_run - create and wake a thread.
 * @threadfn: the function to run until signal_pending(current).
 * @data: data ptr for @threadfn.
 * @namefmt: printf-style name for the thread.
 *
 * Description: Convenient wrapper for kthread_create() followed by
 * wake_up_process().  Returns the kthread or ERR_PTR(-ENOMEM).
 */
#define kthread_run(threadfn, data, namefmt, ...)			   \
({									   \
	struct task_struct *__k						   \
		= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
	if (!IS_ERR(__k))						   \
		wake_up_process(__k);					   \
	__k;								   \
})

/**
 * kthread_run_on_cpu - create and wake a cpu bound thread.
 * @threadfn: the function to run until signal_pending(current).
 * @data: data ptr for @threadfn.
 * @cpu: The cpu on which the thread should be bound,
 * @namefmt: printf-style name for the thread. Format is restricted
 *	     to "name.*%u". Code fills in cpu number.
 *
 * Description: Convenient wrapper for kthread_create_on_cpu()
 * followed by wake_up_process().  Returns the kthread or
 * ERR_PTR(-ENOMEM).
 */
static inline struct task_struct *
kthread_run_on_cpu(int (*threadfn)(void *data), void *data,
			unsigned int cpu, const char *namefmt)
{
	struct task_struct *p;

	p = kthread_create_on_cpu(threadfn, data, cpu, namefmt);
	if (!IS_ERR(p))
		wake_up_process(p);

	return p;
}

void free_kthread_struct(struct task_struct *k);
void kthread_bind(struct task_struct *k, unsigned int cpu);
void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
int kthread_stop(struct task_struct *k);
bool kthread_should_stop(void);
bool kthread_should_park(void);
bool __kthread_should_park(struct task_struct *k);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_func(struct task_struct *k);
void *kthread_data(struct task_struct *k);
void *kthread_probe_data(struct task_struct *k);
int kthread_park(struct task_struct *k);
void kthread_unpark(struct task_struct *k);
void kthread_parkme(void);
void kthread_exit(long result) __noreturn;
void kthread_complete_and_exit(struct completion *, long) __noreturn;

int kthreadd(void *unused);
extern struct task_struct *kthreadd_task;
extern int tsk_fork_get_node(struct task_struct *tsk);

/*
 * Simple work processor based on kthread.
 *
 * This provides easier way to make use of kthreads.  A kthread_work
 * can be queued and flushed using queue/kthread_flush_work()
 * respectively.  Queued kthread_works are processed by a kthread
 * running kthread_worker_fn().
 */
struct kthread_work;
typedef void (*kthread_work_func_t)(struct kthread_work *work);
void kthread_delayed_work_timer_fn(struct timer_list *t);

enum {
	KTW_FREEZABLE		= 1 << 0,	/* freeze during suspend */
};

struct kthread_worker {
	unsigned int		flags;
	raw_spinlock_t		lock;
	struct list_head	work_list;
	struct list_head	delayed_work_list;
	struct task_struct	*task;
	struct kthread_work	*current_work;
};

struct kthread_work {
	struct list_head	node;
	kthread_work_func_t	func;
	struct kthread_worker	*worker;
	/* Number of canceling calls that are running at the moment. */
	int			canceling;
};

struct kthread_delayed_work {
	struct kthread_work work;
	struct timer_list timer;
};

#define KTHREAD_WORK_INIT(work, fn)	{				\
	.node = LIST_HEAD_INIT((work).node),				\
	.func = (fn),							\
	}

#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {				\
	.work = KTHREAD_WORK_INIT((dwork).work, (fn)),			\
	.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
				     TIMER_IRQSAFE),			\
	}

#define DEFINE_KTHREAD_WORK(work, fn)					\
	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)

#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)				\
	struct kthread_delayed_work dwork =				\
		KTHREAD_DELAYED_WORK_INIT(dwork, fn)

extern void __kthread_init_worker(struct kthread_worker *worker,
			const char *name, struct lock_class_key *key);

#define kthread_init_worker(worker)					\
	do {								\
		static struct lock_class_key __key;			\
		__kthread_init_worker((worker), "("#worker")->lock", &__key); \
	} while (0)

#define kthread_init_work(work, fn)					\
	do {								\
		memset((work), 0, sizeof(struct kthread_work));		\
		INIT_LIST_HEAD(&(work)->node);				\
		(work)->func = (fn);					\
	} while (0)

#define kthread_init_delayed_work(dwork, fn)				\
	do {								\
		kthread_init_work(&(dwork)->work, (fn));		\
		timer_setup(&(dwork)->timer,				\
			     kthread_delayed_work_timer_fn,		\
			     TIMER_IRQSAFE);				\
	} while (0)

int kthread_worker_fn(void *worker_ptr);

__printf(2, 3)
struct kthread_worker *
kthread_create_worker(unsigned int flags, const char namefmt[], ...);

__printf(3, 4) struct kthread_worker *
kthread_create_worker_on_cpu(int cpu, unsigned int flags,
			     const char namefmt[], ...);

bool kthread_queue_work(struct kthread_worker *worker,
			struct kthread_work *work);

bool kthread_queue_delayed_work(struct kthread_worker *worker,
				struct kthread_delayed_work *dwork,
				unsigned long delay);

bool kthread_mod_delayed_work(struct kthread_worker *worker,
			      struct kthread_delayed_work *dwork,
			      unsigned long delay);

void kthread_flush_work(struct kthread_work *work);
void kthread_flush_worker(struct kthread_worker *worker);

bool kthread_cancel_work_sync(struct kthread_work *work);
bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);

void kthread_destroy_worker(struct kthread_worker *worker);

void kthread_use_mm(struct mm_struct *mm);
void kthread_unuse_mm(struct mm_struct *mm);

struct cgroup_subsys_state;

#ifdef CONFIG_BLK_CGROUP
void kthread_associate_blkcg(struct cgroup_subsys_state *css);
struct cgroup_subsys_state *kthread_blkcg(void);
#else
static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
#endif
#endif /* _LINUX_KTHREAD_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef _LINUX_KTHREAD_H
	3	#define _LINUX_KTHREAD_H
	4	/* Simple interface for creating and stopping kernel threads without mess. */
	5	#include <linux/err.h>
	6	#include <linux/sched.h>
	7
9bf5b9eb CH	8	struct mm_struct;
9bf5b9eb CH	9
b9075fa9	10	__printf(4, 5)
207205a2 ED	11	struct task_struct kthread_create_on_node(int (threadfn)(void *data),
	12	void *data,
	13	int node,
b9075fa9	14	const char namefmt[], ...);
207205a2	15
e154ccc8 JC	16	/**
	17	* kthread_create - create a kthread on the current node
	18	* @threadfn: the function to run in the thread
	19	* @data: data pointer for @threadfn()
	20	* @namefmt: printf-style format string for the thread name
20ce0c2d	21	* @arg: arguments for @namefmt.
e154ccc8 JC	22	*
	23	* This macro will create a kthread on the current node, leaving it in
	24	* the stopped state. This is just a helper for kthread_create_on_node();
	25	* see the documentation there for more details.
	26	*/
207205a2	27	#define kthread_create(threadfn, data, namefmt, arg...) \
e9f06986	28	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
207205a2	29
1da177e4	30
2a1d4460 TG	31	struct task_struct kthread_create_on_cpu(int (threadfn)(void *data),
	32	void *data,
	33	unsigned int cpu,
	34	const char *namefmt);
	35
d6986ce2	36	void get_kthread_comm(char buf, size_t buf_size, struct task_struct tsk);
40966e31	37	bool set_kthread_struct(struct task_struct *p);
00b89fe0	38
ac687e6e PZ	39	void kthread_set_per_cpu(struct task_struct *k, int cpu);
	40	bool kthread_is_per_cpu(struct task_struct *k);
	41
1da177e4	42	/**
9e37bd30	43	* kthread_run - create and wake a thread.
1da177e4 LT	44	* @threadfn: the function to run until signal_pending(current).
	45	* @data: data ptr for @threadfn.
	46	* @namefmt: printf-style name for the thread.
	47	*
	48	* Description: Convenient wrapper for kthread_create() followed by
9e37bd30 RD	49	* wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
9e37bd30 RD	50	*/
1da177e4 LT	51	#define kthread_run(threadfn, data, namefmt, ...) \
	52	({ \
	53	struct task_struct *__k \
	54	= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
	55	if (!IS_ERR(__k)) \
	56	wake_up_process(__k); \
	57	__k; \
	58	})
	59
800977f6 CH	60	/**
	61	* kthread_run_on_cpu - create and wake a cpu bound thread.
	62	* @threadfn: the function to run until signal_pending(current).
	63	* @data: data ptr for @threadfn.
	64	* @cpu: The cpu on which the thread should be bound,
	65	* @namefmt: printf-style name for the thread. Format is restricted
	66	* to "name.*%u". Code fills in cpu number.
	67	*
	68	* Description: Convenient wrapper for kthread_create_on_cpu()
	69	* followed by wake_up_process(). Returns the kthread or
	70	* ERR_PTR(-ENOMEM).
	71	*/
	72	static inline struct task_struct *
	73	kthread_run_on_cpu(int (threadfn)(void data), void *data,
	74	unsigned int cpu, const char *namefmt)
	75	{
	76	struct task_struct *p;
	77
	78	p = kthread_create_on_cpu(threadfn, data, cpu, namefmt);
	79	if (!IS_ERR(p))
	80	wake_up_process(p);
	81
	82	return p;
	83	}
	84
1da5c46f	85	void free_kthread_struct(struct task_struct *k);
1da177e4	86	void kthread_bind(struct task_struct *k, unsigned int cpu);
25834c73	87	void kthread_bind_mask(struct task_struct k, const struct cpumask mask);
1da177e4	88	int kthread_stop(struct task_struct *k);
2a1d4460 TG	89	bool kthread_should_stop(void);
2a1d4460 TG	90	bool kthread_should_park(void);
0121805d	91	bool __kthread_should_park(struct task_struct *k);
8a32c441	92	bool kthread_freezable_should_stop(bool *was_frozen);
52782c92	93	void kthread_func(struct task_struct k);
82805ab7	94	void kthread_data(struct task_struct k);
e700591a	95	void kthread_probe_data(struct task_struct k);
2a1d4460 TG	96	int kthread_park(struct task_struct *k);
	97	void kthread_unpark(struct task_struct *k);
	98	void kthread_parkme(void);
bbda86e9	99	void kthread_exit(long result) __noreturn;
cead1855	100	void kthread_complete_and_exit(struct completion *, long) __noreturn;
1da177e4	101
73c27992 EB	102	int kthreadd(void *unused);
73c27992 EB	103	extern struct task_struct *kthreadd_task;
207205a2	104	extern int tsk_fork_get_node(struct task_struct *tsk);
73c27992	105
b56c0d89 TH	106	/*
	107	* Simple work processor based on kthread.
	108	*
	109	* This provides easier way to make use of kthreads. A kthread_work
3989144f	110	* can be queued and flushed using queue/kthread_flush_work()
b56c0d89 TH	111	* respectively. Queued kthread_works are processed by a kthread
b56c0d89 TH	112	* running kthread_worker_fn().
b56c0d89 TH	113	*/
	114	struct kthread_work;
	115	typedef void (kthread_work_func_t)(struct kthread_work work);
fe5c3b69	116	void kthread_delayed_work_timer_fn(struct timer_list *t);
b56c0d89	117
dbf52682 PM	118	enum {
	119	KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
	120	};
	121
b56c0d89	122	struct kthread_worker {
dbf52682	123	unsigned int flags;
fe99a4f4	124	raw_spinlock_t lock;
b56c0d89	125	struct list_head work_list;
22597dc3	126	struct list_head delayed_work_list;
b56c0d89	127	struct task_struct *task;
46f3d976	128	struct kthread_work *current_work;
b56c0d89 TH	129	};
	130
	131	struct kthread_work {
	132	struct list_head node;
	133	kthread_work_func_t func;
46f3d976	134	struct kthread_worker *worker;
37be45d4 PM	135	/* Number of canceling calls that are running at the moment. */
37be45d4 PM	136	int canceling;
b56c0d89 TH	137	};
b56c0d89 TH	138
22597dc3 PM	139	struct kthread_delayed_work {
	140	struct kthread_work work;
	141	struct timer_list timer;
	142	};
	143
b56c0d89 TH	144	#define KTHREAD_WORK_INIT(work, fn) { \
	145	.node = LIST_HEAD_INIT((work).node), \
	146	.func = (fn), \
b56c0d89 TH	147	}
b56c0d89 TH	148
22597dc3 PM	149	#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
22597dc3 PM	150	.work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
841b86f3	151	.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
22597dc3 PM	152	TIMER_IRQSAFE), \
	153	}
	154
b56c0d89 TH	155	#define DEFINE_KTHREAD_WORK(work, fn) \
	156	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
	157
22597dc3 PM	158	#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
	159	struct kthread_delayed_work dwork = \
	160	KTHREAD_DELAYED_WORK_INIT(dwork, fn)
	161
3989144f	162	extern void __kthread_init_worker(struct kthread_worker *worker,
4f32e9b1 YZ	163	const char name, struct lock_class_key key);
4f32e9b1 YZ	164
3989144f	165	#define kthread_init_worker(worker) \
4f32e9b1 YZ	166	do { \
4f32e9b1 YZ	167	static struct lock_class_key __key; \
3989144f	168	__kthread_init_worker((worker), "("#worker")->lock", &__key); \
4f32e9b1 YZ	169	} while (0)
4f32e9b1 YZ	170
3989144f	171	#define kthread_init_work(work, fn) \
4f32e9b1 YZ	172	do { \
	173	memset((work), 0, sizeof(struct kthread_work)); \
	174	INIT_LIST_HEAD(&(work)->node); \
	175	(work)->func = (fn); \
4f32e9b1	176	} while (0)
b56c0d89	177
22597dc3 PM	178	#define kthread_init_delayed_work(dwork, fn) \
	179	do { \
	180	kthread_init_work(&(dwork)->work, (fn)); \
ad01423a	181	timer_setup(&(dwork)->timer, \
98c985d7 PM	182	kthread_delayed_work_timer_fn, \
98c985d7 PM	183	TIMER_IRQSAFE); \
22597dc3 PM	184	} while (0)
22597dc3 PM	185
b56c0d89 TH	186	int kthread_worker_fn(void *worker_ptr);
b56c0d89 TH	187
dbf52682	188	__printf(2, 3)
fbae2d44	189	struct kthread_worker *
dbf52682	190	kthread_create_worker(unsigned int flags, const char namefmt[], ...);
fbae2d44	191
c0b942a7	192	__printf(3, 4) struct kthread_worker *
dbf52682 PM	193	kthread_create_worker_on_cpu(int cpu, unsigned int flags,
dbf52682 PM	194	const char namefmt[], ...);
fbae2d44	195
3989144f	196	bool kthread_queue_work(struct kthread_worker *worker,
b56c0d89	197	struct kthread_work *work);
22597dc3 PM	198
	199	bool kthread_queue_delayed_work(struct kthread_worker *worker,
	200	struct kthread_delayed_work *dwork,
	201	unsigned long delay);
	202
9a6b06c8 PM	203	bool kthread_mod_delayed_work(struct kthread_worker *worker,
	204	struct kthread_delayed_work *dwork,
	205	unsigned long delay);
	206
3989144f PM	207	void kthread_flush_work(struct kthread_work *work);
3989144f PM	208	void kthread_flush_worker(struct kthread_worker *worker);
b56c0d89	209
37be45d4 PM	210	bool kthread_cancel_work_sync(struct kthread_work *work);
	211	bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
	212
35033fe9 PM	213	void kthread_destroy_worker(struct kthread_worker *worker);
35033fe9 PM	214
f5678e7f CH	215	void kthread_use_mm(struct mm_struct *mm);
f5678e7f CH	216	void kthread_unuse_mm(struct mm_struct *mm);
9bf5b9eb	217
8af0c18a SB	218	struct cgroup_subsys_state;
8af0c18a SB	219
0b508bc9	220	#ifdef CONFIG_BLK_CGROUP
05e3db95 SL	221	void kthread_associate_blkcg(struct cgroup_subsys_state *css);
	222	struct cgroup_subsys_state *kthread_blkcg(void);
	223	#else
	224	static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
05e3db95	225	#endif
1da177e4	226	#endif /* _LINUX_KTHREAD_H */