[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>

__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);

/**
 * 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;								   \
})

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_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);

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_WORKER_INIT(worker)	{				\
	.lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock),		\
	.work_list = LIST_HEAD_INIT((worker).work_list),		\
	.delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
	}

#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_WORKER(worker)					\
	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)

#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)

/*
 * kthread_worker.lock needs its own lockdep class key when defined on
 * stack with lockdep enabled.  Use the following macros in such cases.
 */
#ifdef CONFIG_LOCKDEP
# define KTHREAD_WORKER_INIT_ONSTACK(worker)				\
	({ kthread_init_worker(&worker); worker; })
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker)				\
	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
#else
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
#endif

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, 0);		\
	} 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);

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) { }
static inline struct cgroup_subsys_state *kthread_blkcg(void)
{
	return NULL;
}
#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
b9075fa9	8	__printf(4, 5)
207205a2 ED	9	struct task_struct kthread_create_on_node(int (threadfn)(void *data),
	10	void *data,
	11	int node,
b9075fa9	12	const char namefmt[], ...);
207205a2	13
e154ccc8 JC	14	/**
	15	* kthread_create - create a kthread on the current node
	16	* @threadfn: the function to run in the thread
	17	* @data: data pointer for @threadfn()
	18	* @namefmt: printf-style format string for the thread name
d16977f3	19	* @arg...: arguments for @namefmt.
e154ccc8 JC	20	*
	21	* This macro will create a kthread on the current node, leaving it in
	22	* the stopped state. This is just a helper for kthread_create_on_node();
	23	* see the documentation there for more details.
	24	*/
207205a2	25	#define kthread_create(threadfn, data, namefmt, arg...) \
e9f06986	26	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
207205a2	27
1da177e4	28
2a1d4460 TG	29	struct task_struct kthread_create_on_cpu(int (threadfn)(void *data),
	30	void *data,
	31	unsigned int cpu,
	32	const char *namefmt);
	33
1da177e4	34	/**
9e37bd30	35	* kthread_run - create and wake a thread.
1da177e4 LT	36	* @threadfn: the function to run until signal_pending(current).
	37	* @data: data ptr for @threadfn.
	38	* @namefmt: printf-style name for the thread.
	39	*
	40	* Description: Convenient wrapper for kthread_create() followed by
9e37bd30 RD	41	* wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
9e37bd30 RD	42	*/
1da177e4 LT	43	#define kthread_run(threadfn, data, namefmt, ...) \
	44	({ \
	45	struct task_struct *__k \
	46	= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
	47	if (!IS_ERR(__k)) \
	48	wake_up_process(__k); \
	49	__k; \
	50	})
	51
1da5c46f	52	void free_kthread_struct(struct task_struct *k);
1da177e4	53	void kthread_bind(struct task_struct *k, unsigned int cpu);
25834c73	54	void kthread_bind_mask(struct task_struct k, const struct cpumask mask);
1da177e4	55	int kthread_stop(struct task_struct *k);
2a1d4460 TG	56	bool kthread_should_stop(void);
2a1d4460 TG	57	bool kthread_should_park(void);
0121805d	58	bool __kthread_should_park(struct task_struct *k);
8a32c441	59	bool kthread_freezable_should_stop(bool *was_frozen);
82805ab7	60	void kthread_data(struct task_struct k);
e700591a	61	void kthread_probe_data(struct task_struct k);
2a1d4460 TG	62	int kthread_park(struct task_struct *k);
	63	void kthread_unpark(struct task_struct *k);
	64	void kthread_parkme(void);
1da177e4	65
73c27992 EB	66	int kthreadd(void *unused);
73c27992 EB	67	extern struct task_struct *kthreadd_task;
207205a2	68	extern int tsk_fork_get_node(struct task_struct *tsk);
73c27992	69
b56c0d89 TH	70	/*
	71	* Simple work processor based on kthread.
	72	*
	73	* This provides easier way to make use of kthreads. A kthread_work
3989144f	74	* can be queued and flushed using queue/kthread_flush_work()
b56c0d89 TH	75	* respectively. Queued kthread_works are processed by a kthread
b56c0d89 TH	76	* running kthread_worker_fn().
b56c0d89 TH	77	*/
	78	struct kthread_work;
	79	typedef void (kthread_work_func_t)(struct kthread_work work);
fe5c3b69	80	void kthread_delayed_work_timer_fn(struct timer_list *t);
b56c0d89	81
dbf52682 PM	82	enum {
	83	KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
	84	};
	85
b56c0d89	86	struct kthread_worker {
dbf52682	87	unsigned int flags;
fe99a4f4	88	raw_spinlock_t lock;
b56c0d89	89	struct list_head work_list;
22597dc3	90	struct list_head delayed_work_list;
b56c0d89	91	struct task_struct *task;
46f3d976	92	struct kthread_work *current_work;
b56c0d89 TH	93	};
	94
	95	struct kthread_work {
	96	struct list_head node;
	97	kthread_work_func_t func;
46f3d976	98	struct kthread_worker *worker;
37be45d4 PM	99	/* Number of canceling calls that are running at the moment. */
37be45d4 PM	100	int canceling;
b56c0d89 TH	101	};
b56c0d89 TH	102
22597dc3 PM	103	struct kthread_delayed_work {
	104	struct kthread_work work;
	105	struct timer_list timer;
	106	};
	107
b56c0d89	108	#define KTHREAD_WORKER_INIT(worker) { \
fe99a4f4	109	.lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \
b56c0d89	110	.work_list = LIST_HEAD_INIT((worker).work_list), \
22597dc3	111	.delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
b56c0d89 TH	112	}
	113
	114	#define KTHREAD_WORK_INIT(work, fn) { \
	115	.node = LIST_HEAD_INIT((work).node), \
	116	.func = (fn), \
b56c0d89 TH	117	}
b56c0d89 TH	118
22597dc3 PM	119	#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
22597dc3 PM	120	.work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
841b86f3	121	.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
22597dc3 PM	122	TIMER_IRQSAFE), \
	123	}
	124
b56c0d89 TH	125	#define DEFINE_KTHREAD_WORKER(worker) \
	126	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
	127
	128	#define DEFINE_KTHREAD_WORK(work, fn) \
	129	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
	130
22597dc3 PM	131	#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
	132	struct kthread_delayed_work dwork = \
	133	KTHREAD_DELAYED_WORK_INIT(dwork, fn)
	134
4f32e9b1	135	/*
95847e1b LJ	136	* kthread_worker.lock needs its own lockdep class key when defined on
95847e1b LJ	137	* stack with lockdep enabled. Use the following macros in such cases.
4f32e9b1 YZ	138	*/
	139	#ifdef CONFIG_LOCKDEP
	140	# define KTHREAD_WORKER_INIT_ONSTACK(worker) \
3989144f	141	({ kthread_init_worker(&worker); worker; })
4f32e9b1 YZ	142	# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
4f32e9b1 YZ	143	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
4f32e9b1 YZ	144	#else
4f32e9b1 YZ	145	# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
4f32e9b1 YZ	146	#endif
4f32e9b1 YZ	147
3989144f	148	extern void __kthread_init_worker(struct kthread_worker *worker,
4f32e9b1 YZ	149	const char name, struct lock_class_key key);
4f32e9b1 YZ	150
3989144f	151	#define kthread_init_worker(worker) \
4f32e9b1 YZ	152	do { \
4f32e9b1 YZ	153	static struct lock_class_key __key; \
3989144f	154	__kthread_init_worker((worker), "("#worker")->lock", &__key); \
4f32e9b1 YZ	155	} while (0)
4f32e9b1 YZ	156
3989144f	157	#define kthread_init_work(work, fn) \
4f32e9b1 YZ	158	do { \
	159	memset((work), 0, sizeof(struct kthread_work)); \
	160	INIT_LIST_HEAD(&(work)->node); \
	161	(work)->func = (fn); \
4f32e9b1	162	} while (0)
b56c0d89	163
22597dc3 PM	164	#define kthread_init_delayed_work(dwork, fn) \
	165	do { \
	166	kthread_init_work(&(dwork)->work, (fn)); \
ad01423a SAS	167	timer_setup(&(dwork)->timer, \
ad01423a SAS	168	kthread_delayed_work_timer_fn, 0); \
22597dc3 PM	169	} while (0)
22597dc3 PM	170
b56c0d89 TH	171	int kthread_worker_fn(void *worker_ptr);
b56c0d89 TH	172
dbf52682	173	__printf(2, 3)
fbae2d44	174	struct kthread_worker *
dbf52682	175	kthread_create_worker(unsigned int flags, const char namefmt[], ...);
fbae2d44	176
c0b942a7	177	__printf(3, 4) struct kthread_worker *
dbf52682 PM	178	kthread_create_worker_on_cpu(int cpu, unsigned int flags,
dbf52682 PM	179	const char namefmt[], ...);
fbae2d44	180
3989144f	181	bool kthread_queue_work(struct kthread_worker *worker,
b56c0d89	182	struct kthread_work *work);
22597dc3 PM	183
	184	bool kthread_queue_delayed_work(struct kthread_worker *worker,
	185	struct kthread_delayed_work *dwork,
	186	unsigned long delay);
	187
9a6b06c8 PM	188	bool kthread_mod_delayed_work(struct kthread_worker *worker,
	189	struct kthread_delayed_work *dwork,
	190	unsigned long delay);
	191
3989144f PM	192	void kthread_flush_work(struct kthread_work *work);
3989144f PM	193	void kthread_flush_worker(struct kthread_worker *worker);
b56c0d89	194
37be45d4 PM	195	bool kthread_cancel_work_sync(struct kthread_work *work);
	196	bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
	197
35033fe9 PM	198	void kthread_destroy_worker(struct kthread_worker *worker);
35033fe9 PM	199
8af0c18a SB	200	struct cgroup_subsys_state;
8af0c18a SB	201
0b508bc9	202	#ifdef CONFIG_BLK_CGROUP
05e3db95 SL	203	void kthread_associate_blkcg(struct cgroup_subsys_state *css);
	204	struct cgroup_subsys_state *kthread_blkcg(void);
	205	#else
	206	static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
	207	static inline struct cgroup_subsys_state *kthread_blkcg(void)
	208	{
	209	return NULL;
	210	}
	211	#endif
1da177e4	212	#endif /* _LINUX_KTHREAD_H */