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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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
Eric Dumazet207205a2011-03-22 16:30:44 -07007struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
8 void *data,
9 int node,
10 const char namefmt[], ...)
11 __attribute__((format(printf, 4, 5)));
12
13#define kthread_create(threadfn, data, namefmt, arg...) \
14 kthread_create_on_node(threadfn, data, -1, namefmt, ##arg)
15
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
17/**
Randy Dunlap9e37bd32006-06-25 05:49:19 -070018 * kthread_run - create and wake a thread.
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * @threadfn: the function to run until signal_pending(current).
20 * @data: data ptr for @threadfn.
21 * @namefmt: printf-style name for the thread.
22 *
23 * Description: Convenient wrapper for kthread_create() followed by
Randy Dunlap9e37bd32006-06-25 05:49:19 -070024 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
25 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#define kthread_run(threadfn, data, namefmt, ...) \
27({ \
28 struct task_struct *__k \
29 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
30 if (!IS_ERR(__k)) \
31 wake_up_process(__k); \
32 __k; \
33})
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035void kthread_bind(struct task_struct *k, unsigned int cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036int kthread_stop(struct task_struct *k);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037int kthread_should_stop(void);
Tejun Heo82805ab2010-06-29 10:07:09 +020038void *kthread_data(struct task_struct *k);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Eric W. Biederman73c27992007-05-09 02:34:32 -070040int kthreadd(void *unused);
41extern struct task_struct *kthreadd_task;
Eric Dumazet207205a2011-03-22 16:30:44 -070042extern int tsk_fork_get_node(struct task_struct *tsk);
Eric W. Biederman73c27992007-05-09 02:34:32 -070043
Tejun Heob56c0d82010-06-29 10:07:09 +020044/*
45 * Simple work processor based on kthread.
46 *
47 * This provides easier way to make use of kthreads. A kthread_work
48 * can be queued and flushed using queue/flush_kthread_work()
49 * respectively. Queued kthread_works are processed by a kthread
50 * running kthread_worker_fn().
51 *
52 * A kthread_work can't be freed while it is executing.
53 */
54struct kthread_work;
55typedef void (*kthread_work_func_t)(struct kthread_work *work);
56
57struct kthread_worker {
58 spinlock_t lock;
59 struct list_head work_list;
60 struct task_struct *task;
61};
62
63struct kthread_work {
64 struct list_head node;
65 kthread_work_func_t func;
66 wait_queue_head_t done;
67 atomic_t flushing;
68 int queue_seq;
69 int done_seq;
70};
71
72#define KTHREAD_WORKER_INIT(worker) { \
Thomas Gleixner92578c02011-01-23 15:24:55 +010073 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \
Tejun Heob56c0d82010-06-29 10:07:09 +020074 .work_list = LIST_HEAD_INIT((worker).work_list), \
75 }
76
77#define KTHREAD_WORK_INIT(work, fn) { \
78 .node = LIST_HEAD_INIT((work).node), \
79 .func = (fn), \
80 .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \
81 .flushing = ATOMIC_INIT(0), \
82 }
83
84#define DEFINE_KTHREAD_WORKER(worker) \
85 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
86
87#define DEFINE_KTHREAD_WORK(work, fn) \
88 struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
89
Yong Zhang4f32e9b2010-12-22 10:27:53 +010090/*
91 * kthread_worker.lock and kthread_work.done need their own lockdep class
92 * keys if they are defined on stack with lockdep enabled. Use the
93 * following macros when defining them on stack.
94 */
95#ifdef CONFIG_LOCKDEP
96# define KTHREAD_WORKER_INIT_ONSTACK(worker) \
97 ({ init_kthread_worker(&worker); worker; })
98# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
99 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
100# define KTHREAD_WORK_INIT_ONSTACK(work, fn) \
101 ({ init_kthread_work((&work), fn); work; })
102# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \
103 struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn)
104#else
105# define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
106# define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn)
107#endif
Tejun Heob56c0d82010-06-29 10:07:09 +0200108
Yong Zhang4f32e9b2010-12-22 10:27:53 +0100109extern void __init_kthread_worker(struct kthread_worker *worker,
110 const char *name, struct lock_class_key *key);
111
112#define init_kthread_worker(worker) \
113 do { \
114 static struct lock_class_key __key; \
115 __init_kthread_worker((worker), "("#worker")->lock", &__key); \
116 } while (0)
117
118#define init_kthread_work(work, fn) \
119 do { \
120 memset((work), 0, sizeof(struct kthread_work)); \
121 INIT_LIST_HEAD(&(work)->node); \
122 (work)->func = (fn); \
123 init_waitqueue_head(&(work)->done); \
124 } while (0)
Tejun Heob56c0d82010-06-29 10:07:09 +0200125
126int kthread_worker_fn(void *worker_ptr);
127
128bool queue_kthread_work(struct kthread_worker *worker,
129 struct kthread_work *work);
130void flush_kthread_work(struct kthread_work *work);
131void flush_kthread_worker(struct kthread_worker *worker);
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133#endif /* _LINUX_KTHREAD_H */