[mirror_ubuntu-jammy-kernel.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 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;								   \
})

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);

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,		\
			     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) { }
static inline struct cgroup_subsys_state *kthread_blkcg(void)
{
	return NULL;
}
#endif
#endif /* _LINUX_KTHREAD_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	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
	8	struct mm_struct;
	9
	10	__printf(4, 5)
	11	struct task_struct kthread_create_on_node(int (threadfn)(void *data),
	12	void *data,
	13	int node,
	14	const char namefmt[], ...);
	15
	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
	21	* @arg...: arguments for @namefmt.
	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	*/
	27	#define kthread_create(threadfn, data, namefmt, arg...) \
	28	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
	29
	30
	31	struct task_struct kthread_create_on_cpu(int (threadfn)(void *data),
	32	void *data,
	33	unsigned int cpu,
	34	const char *namefmt);
	35
	36	void kthread_set_per_cpu(struct task_struct *k, int cpu);
	37	bool kthread_is_per_cpu(struct task_struct *k);
	38
	39	/**
	40	* kthread_run - create and wake a thread.
	41	* @threadfn: the function to run until signal_pending(current).
	42	* @data: data ptr for @threadfn.
	43	* @namefmt: printf-style name for the thread.
	44	*
	45	* Description: Convenient wrapper for kthread_create() followed by
	46	* wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
	47	*/
	48	#define kthread_run(threadfn, data, namefmt, ...) \
	49	({ \
	50	struct task_struct *__k \
	51	= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
	52	if (!IS_ERR(__k)) \
	53	wake_up_process(__k); \
	54	__k; \
	55	})
	56
	57	void free_kthread_struct(struct task_struct *k);
	58	void kthread_bind(struct task_struct *k, unsigned int cpu);
	59	void kthread_bind_mask(struct task_struct k, const struct cpumask mask);
	60	int kthread_stop(struct task_struct *k);
	61	bool kthread_should_stop(void);
	62	bool kthread_should_park(void);
	63	bool __kthread_should_park(struct task_struct *k);
	64	bool kthread_freezable_should_stop(bool *was_frozen);
	65	void kthread_func(struct task_struct k);
	66	void kthread_data(struct task_struct k);
	67	void kthread_probe_data(struct task_struct k);
	68	int kthread_park(struct task_struct *k);
	69	void kthread_unpark(struct task_struct *k);
	70	void kthread_parkme(void);
	71
	72	int kthreadd(void *unused);
	73	extern struct task_struct *kthreadd_task;
	74	extern int tsk_fork_get_node(struct task_struct *tsk);
	75
	76	/*
	77	* Simple work processor based on kthread.
	78	*
	79	* This provides easier way to make use of kthreads. A kthread_work
	80	* can be queued and flushed using queue/kthread_flush_work()
	81	* respectively. Queued kthread_works are processed by a kthread
	82	* running kthread_worker_fn().
	83	*/
	84	struct kthread_work;
	85	typedef void (kthread_work_func_t)(struct kthread_work work);
	86	void kthread_delayed_work_timer_fn(struct timer_list *t);
	87
	88	enum {
	89	KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
	90	};
	91
	92	struct kthread_worker {
	93	unsigned int flags;
	94	raw_spinlock_t lock;
	95	struct list_head work_list;
	96	struct list_head delayed_work_list;
	97	struct task_struct *task;
	98	struct kthread_work *current_work;
	99	};
	100
	101	struct kthread_work {
	102	struct list_head node;
	103	kthread_work_func_t func;
	104	struct kthread_worker *worker;
	105	/* Number of canceling calls that are running at the moment. */
	106	int canceling;
	107	};
	108
	109	struct kthread_delayed_work {
	110	struct kthread_work work;
	111	struct timer_list timer;
	112	};
	113
	114	#define KTHREAD_WORKER_INIT(worker) { \
	115	.lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \
	116	.work_list = LIST_HEAD_INIT((worker).work_list), \
	117	.delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
	118	}
	119
	120	#define KTHREAD_WORK_INIT(work, fn) { \
	121	.node = LIST_HEAD_INIT((work).node), \
	122	.func = (fn), \
	123	}
	124
	125	#define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
	126	.work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
	127	.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
	128	TIMER_IRQSAFE), \
	129	}
	130
	131	#define DEFINE_KTHREAD_WORKER(worker) \
	132	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
	133
	134	#define DEFINE_KTHREAD_WORK(work, fn) \
	135	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
	136
	137	#define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
	138	struct kthread_delayed_work dwork = \
	139	KTHREAD_DELAYED_WORK_INIT(dwork, fn)
	140
	141	/*
	142	* kthread_worker.lock needs its own lockdep class key when defined on
	143	* stack with lockdep enabled. Use the following macros in such cases.
	144	*/
	145	#ifdef CONFIG_LOCKDEP
	146	# define KTHREAD_WORKER_INIT_ONSTACK(worker) \
	147	({ kthread_init_worker(&worker); worker; })
	148	# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
	149	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
	150	#else
	151	# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
	152	#endif
	153
	154	extern void __kthread_init_worker(struct kthread_worker *worker,
	155	const char name, struct lock_class_key key);
	156
	157	#define kthread_init_worker(worker) \
	158	do { \
	159	static struct lock_class_key __key; \
	160	__kthread_init_worker((worker), "("#worker")->lock", &__key); \
	161	} while (0)
	162
	163	#define kthread_init_work(work, fn) \
	164	do { \
	165	memset((work), 0, sizeof(struct kthread_work)); \
	166	INIT_LIST_HEAD(&(work)->node); \
	167	(work)->func = (fn); \
	168	} while (0)
	169
	170	#define kthread_init_delayed_work(dwork, fn) \
	171	do { \
	172	kthread_init_work(&(dwork)->work, (fn)); \
	173	timer_setup(&(dwork)->timer, \
	174	kthread_delayed_work_timer_fn, \
	175	TIMER_IRQSAFE); \
	176	} while (0)
	177
	178	int kthread_worker_fn(void *worker_ptr);
	179
	180	__printf(2, 3)
	181	struct kthread_worker *
	182	kthread_create_worker(unsigned int flags, const char namefmt[], ...);
	183
	184	__printf(3, 4) struct kthread_worker *
	185	kthread_create_worker_on_cpu(int cpu, unsigned int flags,
	186	const char namefmt[], ...);
	187
	188	bool kthread_queue_work(struct kthread_worker *worker,
	189	struct kthread_work *work);
	190
	191	bool kthread_queue_delayed_work(struct kthread_worker *worker,
	192	struct kthread_delayed_work *dwork,
	193	unsigned long delay);
	194
	195	bool kthread_mod_delayed_work(struct kthread_worker *worker,
	196	struct kthread_delayed_work *dwork,
	197	unsigned long delay);
	198
	199	void kthread_flush_work(struct kthread_work *work);
	200	void kthread_flush_worker(struct kthread_worker *worker);
	201
	202	bool kthread_cancel_work_sync(struct kthread_work *work);
	203	bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
	204
	205	void kthread_destroy_worker(struct kthread_worker *worker);
	206
	207	void kthread_use_mm(struct mm_struct *mm);
	208	void kthread_unuse_mm(struct mm_struct *mm);
	209
	210	struct cgroup_subsys_state;
	211
	212	#ifdef CONFIG_BLK_CGROUP
	213	void kthread_associate_blkcg(struct cgroup_subsys_state *css);
	214	struct cgroup_subsys_state *kthread_blkcg(void);
	215	#else
	216	static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
	217	static inline struct cgroup_subsys_state *kthread_blkcg(void)
	218	{
	219	return NULL;
	220	}
	221	#endif
	222	#endif /* _LINUX_KTHREAD_H */