4fec8b7758951cf9395613b072659efdce33e1d1
[muen/linux.git] / include / linux / kthread.h
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
7 __printf(4, 5)
8 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
9                                            void *data,
10                                            int node,
11                                            const char namefmt[], ...);
12
13 /**
14  * kthread_create - create a kthread on the current node
15  * @threadfn: the function to run in the thread
16  * @data: data pointer for @threadfn()
17  * @namefmt: printf-style format string for the thread name
18  * @...: arguments for @namefmt.
19  *
20  * This macro will create a kthread on the current node, leaving it in
21  * the stopped state.  This is just a helper for kthread_create_on_node();
22  * see the documentation there for more details.
23  */
24 #define kthread_create(threadfn, data, namefmt, arg...) \
25         kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
26
27
28 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
29                                           void *data,
30                                           unsigned int cpu,
31                                           const char *namefmt);
32
33 /**
34  * kthread_run - create and wake a thread.
35  * @threadfn: the function to run until signal_pending(current).
36  * @data: data ptr for @threadfn.
37  * @namefmt: printf-style name for the thread.
38  *
39  * Description: Convenient wrapper for kthread_create() followed by
40  * wake_up_process().  Returns the kthread or ERR_PTR(-ENOMEM).
41  */
42 #define kthread_run(threadfn, data, namefmt, ...)                          \
43 ({                                                                         \
44         struct task_struct *__k                                            \
45                 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
46         if (!IS_ERR(__k))                                                  \
47                 wake_up_process(__k);                                      \
48         __k;                                                               \
49 })
50
51 void free_kthread_struct(struct task_struct *k);
52 void kthread_bind(struct task_struct *k, unsigned int cpu);
53 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
54 int kthread_stop(struct task_struct *k);
55 bool kthread_should_stop(void);
56 bool kthread_should_park(void);
57 bool kthread_freezable_should_stop(bool *was_frozen);
58 void *kthread_data(struct task_struct *k);
59 void *kthread_probe_data(struct task_struct *k);
60 int kthread_park(struct task_struct *k);
61 void kthread_unpark(struct task_struct *k);
62 void kthread_parkme(void);
63
64 int kthreadd(void *unused);
65 extern struct task_struct *kthreadd_task;
66 extern int tsk_fork_get_node(struct task_struct *tsk);
67
68 /*
69  * Simple work processor based on kthread.
70  *
71  * This provides easier way to make use of kthreads.  A kthread_work
72  * can be queued and flushed using queue/kthread_flush_work()
73  * respectively.  Queued kthread_works are processed by a kthread
74  * running kthread_worker_fn().
75  */
76 struct kthread_work;
77 typedef void (*kthread_work_func_t)(struct kthread_work *work);
78 void kthread_delayed_work_timer_fn(unsigned long __data);
79
80 enum {
81         KTW_FREEZABLE           = 1 << 0,       /* freeze during suspend */
82 };
83
84 struct kthread_worker {
85         unsigned int            flags;
86         spinlock_t              lock;
87         struct list_head        work_list;
88         struct list_head        delayed_work_list;
89         struct task_struct      *task;
90         struct kthread_work     *current_work;
91 };
92
93 struct kthread_work {
94         struct list_head        node;
95         kthread_work_func_t     func;
96         struct kthread_worker   *worker;
97         /* Number of canceling calls that are running at the moment. */
98         int                     canceling;
99 };
100
101 struct kthread_delayed_work {
102         struct kthread_work work;
103         struct timer_list timer;
104 };
105
106 #define KTHREAD_WORKER_INIT(worker)     {                               \
107         .lock = __SPIN_LOCK_UNLOCKED((worker).lock),                    \
108         .work_list = LIST_HEAD_INIT((worker).work_list),                \
109         .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
110         }
111
112 #define KTHREAD_WORK_INIT(work, fn)     {                               \
113         .node = LIST_HEAD_INIT((work).node),                            \
114         .func = (fn),                                                   \
115         }
116
117 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {                          \
118         .work = KTHREAD_WORK_INIT((dwork).work, (fn)),                  \
119         .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,     \
120                                      0, (unsigned long)&(dwork),        \
121                                      TIMER_IRQSAFE),                    \
122         }
123
124 #define DEFINE_KTHREAD_WORKER(worker)                                   \
125         struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
126
127 #define DEFINE_KTHREAD_WORK(work, fn)                                   \
128         struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
129
130 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)                          \
131         struct kthread_delayed_work dwork =                             \
132                 KTHREAD_DELAYED_WORK_INIT(dwork, fn)
133
134 /*
135  * kthread_worker.lock needs its own lockdep class key when defined on
136  * stack with lockdep enabled.  Use the following macros in such cases.
137  */
138 #ifdef CONFIG_LOCKDEP
139 # define KTHREAD_WORKER_INIT_ONSTACK(worker)                            \
140         ({ kthread_init_worker(&worker); worker; })
141 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker)                          \
142         struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
143 #else
144 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
145 #endif
146
147 extern void __kthread_init_worker(struct kthread_worker *worker,
148                         const char *name, struct lock_class_key *key);
149
150 #define kthread_init_worker(worker)                                     \
151         do {                                                            \
152                 static struct lock_class_key __key;                     \
153                 __kthread_init_worker((worker), "("#worker")->lock", &__key); \
154         } while (0)
155
156 #define kthread_init_work(work, fn)                                     \
157         do {                                                            \
158                 memset((work), 0, sizeof(struct kthread_work));         \
159                 INIT_LIST_HEAD(&(work)->node);                          \
160                 (work)->func = (fn);                                    \
161         } while (0)
162
163 #define kthread_init_delayed_work(dwork, fn)                            \
164         do {                                                            \
165                 kthread_init_work(&(dwork)->work, (fn));                \
166                 __setup_timer(&(dwork)->timer,                          \
167                               kthread_delayed_work_timer_fn,            \
168                               (unsigned long)(dwork),                   \
169                               TIMER_IRQSAFE);                           \
170         } while (0)
171
172 int kthread_worker_fn(void *worker_ptr);
173
174 __printf(2, 3)
175 struct kthread_worker *
176 kthread_create_worker(unsigned int flags, const char namefmt[], ...);
177
178 __printf(3, 4) struct kthread_worker *
179 kthread_create_worker_on_cpu(int cpu, unsigned int flags,
180                              const char namefmt[], ...);
181
182 bool kthread_queue_work(struct kthread_worker *worker,
183                         struct kthread_work *work);
184
185 bool kthread_queue_delayed_work(struct kthread_worker *worker,
186                                 struct kthread_delayed_work *dwork,
187                                 unsigned long delay);
188
189 bool kthread_mod_delayed_work(struct kthread_worker *worker,
190                               struct kthread_delayed_work *dwork,
191                               unsigned long delay);
192
193 void kthread_flush_work(struct kthread_work *work);
194 void kthread_flush_worker(struct kthread_worker *worker);
195
196 bool kthread_cancel_work_sync(struct kthread_work *work);
197 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
198
199 void kthread_destroy_worker(struct kthread_worker *worker);
200
201 #endif /* _LINUX_KTHREAD_H */