[linux-2.6-block.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>

struct task_struct *kthread_create(int (*threadfn)(void *data),
				   void *data,
				   const char namefmt[], ...)
	__attribute__((format(printf, 3, 4)));

/**
 * 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);
int kthread_should_stop(void);

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

/*
 * 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().
 *
 * A kthread_work can't be freed while it is executing.
 */
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 {
	struct list_head	node;
	kthread_work_func_t	func;
	wait_queue_head_t	done;
	atomic_t		flushing;
	int			queue_seq;
	int			done_seq;
};

#define KTHREAD_WORKER_INIT(worker)	{				\
	.lock = SPIN_LOCK_UNLOCKED,					\
	.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),		\
	.flushing = ATOMIC_INIT(0),					\
	}

#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)

static inline void init_kthread_worker(struct kthread_worker *worker)
{
	*worker = (struct kthread_worker)KTHREAD_WORKER_INIT(*worker);
}

static inline void init_kthread_work(struct kthread_work *work,
				     kthread_work_func_t fn)
{
	*work = (struct kthread_work)KTHREAD_WORK_INIT(*work, fn);
}

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
1da177e4 LT	7	struct task_struct kthread_create(int (threadfn)(void *data),
1da177e4 LT	8	void *data,
ed9559d3 RR	9	const char namefmt[], ...)
ed9559d3 RR	10	__attribute__((format(printf, 3, 4)));
1da177e4 LT	11
1da177e4 LT	12	/**
9e37bd30	13	* kthread_run - create and wake a thread.
1da177e4 LT	14	* @threadfn: the function to run until signal_pending(current).
	15	* @data: data ptr for @threadfn.
	16	* @namefmt: printf-style name for the thread.
	17	*
	18	* Description: Convenient wrapper for kthread_create() followed by
9e37bd30 RD	19	* wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
9e37bd30 RD	20	*/
1da177e4 LT	21	#define kthread_run(threadfn, data, namefmt, ...) \
	22	({ \
	23	struct task_struct *__k \
	24	= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
	25	if (!IS_ERR(__k)) \
	26	wake_up_process(__k); \
	27	__k; \
	28	})
	29
1da177e4	30	void kthread_bind(struct task_struct *k, unsigned int cpu);
1da177e4	31	int kthread_stop(struct task_struct *k);
1da177e4 LT	32	int kthread_should_stop(void);
1da177e4 LT	33
73c27992 EB	34	int kthreadd(void *unused);
	35	extern struct task_struct *kthreadd_task;
	36
b56c0d89 TH	37	/*
	38	* Simple work processor based on kthread.
	39	*
	40	* This provides easier way to make use of kthreads. A kthread_work
	41	* can be queued and flushed using queue/flush_kthread_work()
	42	* respectively. Queued kthread_works are processed by a kthread
	43	* running kthread_worker_fn().
	44	*
	45	* A kthread_work can't be freed while it is executing.
	46	*/
	47	struct kthread_work;
	48	typedef void (kthread_work_func_t)(struct kthread_work work);
	49
	50	struct kthread_worker {
	51	spinlock_t lock;
	52	struct list_head work_list;
	53	struct task_struct *task;
	54	};
	55
	56	struct kthread_work {
	57	struct list_head node;
	58	kthread_work_func_t func;
	59	wait_queue_head_t done;
	60	atomic_t flushing;
	61	int queue_seq;
	62	int done_seq;
	63	};
	64
	65	#define KTHREAD_WORKER_INIT(worker) { \
	66	.lock = SPIN_LOCK_UNLOCKED, \
	67	.work_list = LIST_HEAD_INIT((worker).work_list), \
	68	}
	69
	70	#define KTHREAD_WORK_INIT(work, fn) { \
	71	.node = LIST_HEAD_INIT((work).node), \
	72	.func = (fn), \
	73	.done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \
	74	.flushing = ATOMIC_INIT(0), \
	75	}
	76
	77	#define DEFINE_KTHREAD_WORKER(worker) \
	78	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
	79
	80	#define DEFINE_KTHREAD_WORK(work, fn) \
	81	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
	82
	83	static inline void init_kthread_worker(struct kthread_worker *worker)
	84	{
	85	worker = (struct kthread_worker)KTHREAD_WORKER_INIT(worker);
	86	}
	87
	88	static inline void init_kthread_work(struct kthread_work *work,
	89	kthread_work_func_t fn)
	90	{
	91	work = (struct kthread_work)KTHREAD_WORK_INIT(work, fn);
	92	}
	93
	94	int kthread_worker_fn(void *worker_ptr);
	95
	96	bool queue_kthread_work(struct kthread_worker *worker,
	97	struct kthread_work *work);
	98	void flush_kthread_work(struct kthread_work *work);
	99	void flush_kthread_worker(struct kthread_worker *worker);
	100
1da177e4	101	#endif /* _LINUX_KTHREAD_H */