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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 */