[deliverable/linux.git] / include / linux / kthread.h

#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[], ...);

#define kthread_create(threadfn, data, namefmt, arg...) \
	kthread_create_on_node(threadfn, data, -1, 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 kthread_bind(struct task_struct *k, unsigned int cpu);
int kthread_stop(struct task_struct *k);
bool kthread_should_stop(void);
bool kthread_should_park(void);
bool kthread_freezable_should_stop(bool *was_frozen);
void *kthread_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/flush_kthread_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);

struct kthread_worker {
	spinlock_t		lock;
	struct list_head	work_list;
	struct task_struct	*task;
	struct kthread_work	*current_work;
};

struct kthread_work {
	struct list_head	node;
	kthread_work_func_t	func;
	wait_queue_head_t	done;
	struct kthread_worker	*worker;
};

#define KTHREAD_WORKER_INIT(worker)	{				\
	.lock = __SPIN_LOCK_UNLOCKED((worker).lock),			\
	.work_list = LIST_HEAD_INIT((worker).work_list),		\
	}

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

#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)

/*
 * kthread_worker.lock and kthread_work.done need their own lockdep class
 * keys if they are defined on stack with lockdep enabled.  Use the
 * following macros when defining them on stack.
 */
#ifdef CONFIG_LOCKDEP
# define KTHREAD_WORKER_INIT_ONSTACK(worker)				\
	({ init_kthread_worker(&worker); worker; })
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker)				\
	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
# define KTHREAD_WORK_INIT_ONSTACK(work, fn)				\
	({ init_kthread_work((&work), fn); work; })
# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn)				\
	struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn)
#else
# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn)
#endif

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

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

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

int kthread_worker_fn(void *worker_ptr);

bool queue_kthread_work(struct kthread_worker *worker,
			struct kthread_work *work);
void flush_kthread_work(struct kthread_work *work);
void flush_kthread_worker(struct kthread_worker *worker);

#endif /* _LINUX_KTHREAD_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_KTHREAD_H
	2	#define _LINUX_KTHREAD_H
	3	/* Simple interface for creating and stopping kernel threads without mess. */
	4	#include <linux/err.h>
	5	#include <linux/sched.h>
	6
b9075fa9	7	__printf(4, 5)
207205a2 ED	8	struct task_struct kthread_create_on_node(int (threadfn)(void *data),
	9	void *data,
	10	int node,
b9075fa9	11	const char namefmt[], ...);
207205a2 ED	12
	13	#define kthread_create(threadfn, data, namefmt, arg...) \
	14	kthread_create_on_node(threadfn, data, -1, namefmt, ##arg)
	15
1da177e4	16
2a1d4460 TG	17	struct task_struct kthread_create_on_cpu(int (threadfn)(void *data),
	18	void *data,
	19	unsigned int cpu,
	20	const char *namefmt);
	21
1da177e4	22	/**
9e37bd30	23	* kthread_run - create and wake a thread.
1da177e4 LT	24	* @threadfn: the function to run until signal_pending(current).
	25	* @data: data ptr for @threadfn.
	26	* @namefmt: printf-style name for the thread.
	27	*
	28	* Description: Convenient wrapper for kthread_create() followed by
9e37bd30 RD	29	* wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
9e37bd30 RD	30	*/
1da177e4 LT	31	#define kthread_run(threadfn, data, namefmt, ...) \
	32	({ \
	33	struct task_struct *__k \
	34	= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
	35	if (!IS_ERR(__k)) \
	36	wake_up_process(__k); \
	37	__k; \
	38	})
	39
1da177e4	40	void kthread_bind(struct task_struct *k, unsigned int cpu);
1da177e4	41	int kthread_stop(struct task_struct *k);
2a1d4460 TG	42	bool kthread_should_stop(void);
2a1d4460 TG	43	bool kthread_should_park(void);
8a32c441	44	bool kthread_freezable_should_stop(bool *was_frozen);
82805ab7	45	void kthread_data(struct task_struct k);
2a1d4460 TG	46	int kthread_park(struct task_struct *k);
	47	void kthread_unpark(struct task_struct *k);
	48	void kthread_parkme(void);
1da177e4	49
73c27992 EB	50	int kthreadd(void *unused);
73c27992 EB	51	extern struct task_struct *kthreadd_task;
207205a2	52	extern int tsk_fork_get_node(struct task_struct *tsk);
73c27992	53
b56c0d89 TH	54	/*
	55	* Simple work processor based on kthread.
	56	*
	57	* This provides easier way to make use of kthreads. A kthread_work
	58	* can be queued and flushed using queue/flush_kthread_work()
	59	* respectively. Queued kthread_works are processed by a kthread
	60	* running kthread_worker_fn().
b56c0d89 TH	61	*/
	62	struct kthread_work;
	63	typedef void (kthread_work_func_t)(struct kthread_work work);
	64
	65	struct kthread_worker {
	66	spinlock_t lock;
	67	struct list_head work_list;
	68	struct task_struct *task;
46f3d976	69	struct kthread_work *current_work;
b56c0d89 TH	70	};
	71
	72	struct kthread_work {
	73	struct list_head node;
	74	kthread_work_func_t func;
	75	wait_queue_head_t done;
46f3d976	76	struct kthread_worker *worker;
b56c0d89 TH	77	};
	78
	79	#define KTHREAD_WORKER_INIT(worker) { \
92578c0b	80	.lock = __SPIN_LOCK_UNLOCKED((worker).lock), \
b56c0d89 TH	81	.work_list = LIST_HEAD_INIT((worker).work_list), \
	82	}
	83
	84	#define KTHREAD_WORK_INIT(work, fn) { \
	85	.node = LIST_HEAD_INIT((work).node), \
	86	.func = (fn), \
	87	.done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \
b56c0d89 TH	88	}
	89
	90	#define DEFINE_KTHREAD_WORKER(worker) \
	91	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
	92
	93	#define DEFINE_KTHREAD_WORK(work, fn) \
	94	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
	95
4f32e9b1 YZ	96	/*
	97	* kthread_worker.lock and kthread_work.done need their own lockdep class
	98	* keys if they are defined on stack with lockdep enabled. Use the
	99	* following macros when defining them on stack.
	100	*/
	101	#ifdef CONFIG_LOCKDEP
	102	# define KTHREAD_WORKER_INIT_ONSTACK(worker) \
	103	({ init_kthread_worker(&worker); worker; })
	104	# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
	105	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
	106	# define KTHREAD_WORK_INIT_ONSTACK(work, fn) \
	107	({ init_kthread_work((&work), fn); work; })
	108	# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \
	109	struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn)
	110	#else
	111	# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
	112	# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn)
	113	#endif
	114
	115	extern void __init_kthread_worker(struct kthread_worker *worker,
	116	const char name, struct lock_class_key key);
	117
	118	#define init_kthread_worker(worker) \
	119	do { \
	120	static struct lock_class_key __key; \
	121	__init_kthread_worker((worker), "("#worker")->lock", &__key); \
	122	} while (0)
	123
	124	#define init_kthread_work(work, fn) \
	125	do { \
	126	memset((work), 0, sizeof(struct kthread_work)); \
	127	INIT_LIST_HEAD(&(work)->node); \
	128	(work)->func = (fn); \
	129	init_waitqueue_head(&(work)->done); \
	130	} while (0)
b56c0d89 TH	131
	132	int kthread_worker_fn(void *worker_ptr);
	133
	134	bool queue_kthread_work(struct kthread_worker *worker,
	135	struct kthread_work *work);
	136	void flush_kthread_work(struct kthread_work *work);
	137	void flush_kthread_worker(struct kthread_worker *worker);
	138
1da177e4	139	#endif /* _LINUX_KTHREAD_H */