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1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _LINUX_KTHREAD_H
3 : #define _LINUX_KTHREAD_H
4 : /* Simple interface for creating and stopping kernel threads without mess. */
5 : #include <linux/err.h>
6 : #include <linux/sched.h>
7 :
8 : struct mm_struct;
9 :
10 : __printf(4, 5)
11 : struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
12 : void *data,
13 : int node,
14 : const char namefmt[], ...);
15 :
16 : /**
17 : * kthread_create - create a kthread on the current node
18 : * @threadfn: the function to run in the thread
19 : * @data: data pointer for @threadfn()
20 : * @namefmt: printf-style format string for the thread name
21 : * @arg...: arguments for @namefmt.
22 : *
23 : * This macro will create a kthread on the current node, leaving it in
24 : * the stopped state. This is just a helper for kthread_create_on_node();
25 : * see the documentation there for more details.
26 : */
27 : #define kthread_create(threadfn, data, namefmt, arg...) \
28 : kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
29 :
30 :
31 : struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
32 : void *data,
33 : unsigned int cpu,
34 : const char *namefmt);
35 :
36 : void kthread_set_per_cpu(struct task_struct *k, int cpu);
37 : bool kthread_is_per_cpu(struct task_struct *k);
38 :
39 : /**
40 : * kthread_run - create and wake a thread.
41 : * @threadfn: the function to run until signal_pending(current).
42 : * @data: data ptr for @threadfn.
43 : * @namefmt: printf-style name for the thread.
44 : *
45 : * Description: Convenient wrapper for kthread_create() followed by
46 : * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
47 : */
48 : #define kthread_run(threadfn, data, namefmt, ...) \
49 : ({ \
50 : struct task_struct *__k \
51 : = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
52 : if (!IS_ERR(__k)) \
53 : wake_up_process(__k); \
54 : __k; \
55 : })
56 :
57 : void free_kthread_struct(struct task_struct *k);
58 : void kthread_bind(struct task_struct *k, unsigned int cpu);
59 : void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
60 : int kthread_stop(struct task_struct *k);
61 : bool kthread_should_stop(void);
62 : bool kthread_should_park(void);
63 : bool __kthread_should_park(struct task_struct *k);
64 : bool kthread_freezable_should_stop(bool *was_frozen);
65 : void *kthread_func(struct task_struct *k);
66 : void *kthread_data(struct task_struct *k);
67 : void *kthread_probe_data(struct task_struct *k);
68 : int kthread_park(struct task_struct *k);
69 : void kthread_unpark(struct task_struct *k);
70 : void kthread_parkme(void);
71 :
72 : int kthreadd(void *unused);
73 : extern struct task_struct *kthreadd_task;
74 : extern int tsk_fork_get_node(struct task_struct *tsk);
75 :
76 : /*
77 : * Simple work processor based on kthread.
78 : *
79 : * This provides easier way to make use of kthreads. A kthread_work
80 : * can be queued and flushed using queue/kthread_flush_work()
81 : * respectively. Queued kthread_works are processed by a kthread
82 : * running kthread_worker_fn().
83 : */
84 : struct kthread_work;
85 : typedef void (*kthread_work_func_t)(struct kthread_work *work);
86 : void kthread_delayed_work_timer_fn(struct timer_list *t);
87 :
88 : enum {
89 : KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
90 : };
91 :
92 : struct kthread_worker {
93 : unsigned int flags;
94 : raw_spinlock_t lock;
95 : struct list_head work_list;
96 : struct list_head delayed_work_list;
97 : struct task_struct *task;
98 : struct kthread_work *current_work;
99 : };
100 :
101 : struct kthread_work {
102 : struct list_head node;
103 : kthread_work_func_t func;
104 : struct kthread_worker *worker;
105 : /* Number of canceling calls that are running at the moment. */
106 : int canceling;
107 : };
108 :
109 : struct kthread_delayed_work {
110 : struct kthread_work work;
111 : struct timer_list timer;
112 : };
113 :
114 : #define KTHREAD_WORKER_INIT(worker) { \
115 : .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \
116 : .work_list = LIST_HEAD_INIT((worker).work_list), \
117 : .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
118 : }
119 :
120 : #define KTHREAD_WORK_INIT(work, fn) { \
121 : .node = LIST_HEAD_INIT((work).node), \
122 : .func = (fn), \
123 : }
124 :
125 : #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
126 : .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
127 : .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
128 : TIMER_IRQSAFE), \
129 : }
130 :
131 : #define DEFINE_KTHREAD_WORKER(worker) \
132 : struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
133 :
134 : #define DEFINE_KTHREAD_WORK(work, fn) \
135 : struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
136 :
137 : #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
138 : struct kthread_delayed_work dwork = \
139 : KTHREAD_DELAYED_WORK_INIT(dwork, fn)
140 :
141 : /*
142 : * kthread_worker.lock needs its own lockdep class key when defined on
143 : * stack with lockdep enabled. Use the following macros in such cases.
144 : */
145 : #ifdef CONFIG_LOCKDEP
146 : # define KTHREAD_WORKER_INIT_ONSTACK(worker) \
147 : ({ kthread_init_worker(&worker); worker; })
148 : # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
149 : struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
150 : #else
151 : # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
152 : #endif
153 :
154 : extern void __kthread_init_worker(struct kthread_worker *worker,
155 : const char *name, struct lock_class_key *key);
156 :
157 : #define kthread_init_worker(worker) \
158 : do { \
159 : static struct lock_class_key __key; \
160 : __kthread_init_worker((worker), "("#worker")->lock", &__key); \
161 : } while (0)
162 :
163 : #define kthread_init_work(work, fn) \
164 : do { \
165 : memset((work), 0, sizeof(struct kthread_work)); \
166 : INIT_LIST_HEAD(&(work)->node); \
167 : (work)->func = (fn); \
168 : } while (0)
169 :
170 : #define kthread_init_delayed_work(dwork, fn) \
171 : do { \
172 : kthread_init_work(&(dwork)->work, (fn)); \
173 : timer_setup(&(dwork)->timer, \
174 : kthread_delayed_work_timer_fn, \
175 : TIMER_IRQSAFE); \
176 : } while (0)
177 :
178 : int kthread_worker_fn(void *worker_ptr);
179 :
180 : __printf(2, 3)
181 : struct kthread_worker *
182 : kthread_create_worker(unsigned int flags, const char namefmt[], ...);
183 :
184 : __printf(3, 4) struct kthread_worker *
185 : kthread_create_worker_on_cpu(int cpu, unsigned int flags,
186 : const char namefmt[], ...);
187 :
188 : bool kthread_queue_work(struct kthread_worker *worker,
189 : struct kthread_work *work);
190 :
191 : bool kthread_queue_delayed_work(struct kthread_worker *worker,
192 : struct kthread_delayed_work *dwork,
193 : unsigned long delay);
194 :
195 : bool kthread_mod_delayed_work(struct kthread_worker *worker,
196 : struct kthread_delayed_work *dwork,
197 : unsigned long delay);
198 :
199 : void kthread_flush_work(struct kthread_work *work);
200 : void kthread_flush_worker(struct kthread_worker *worker);
201 :
202 : bool kthread_cancel_work_sync(struct kthread_work *work);
203 : bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
204 :
205 : void kthread_destroy_worker(struct kthread_worker *worker);
206 :
207 : void kthread_use_mm(struct mm_struct *mm);
208 : void kthread_unuse_mm(struct mm_struct *mm);
209 :
210 : struct cgroup_subsys_state;
211 :
212 : #ifdef CONFIG_BLK_CGROUP
213 : void kthread_associate_blkcg(struct cgroup_subsys_state *css);
214 : struct cgroup_subsys_state *kthread_blkcg(void);
215 : #else
216 0 : static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
217 : static inline struct cgroup_subsys_state *kthread_blkcg(void)
218 : {
219 : return NULL;
220 : }
221 : #endif
222 : #endif /* _LINUX_KTHREAD_H */
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