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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 : : __printf(4, 5)
9 : : struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
10 : : void *data,
11 : : int node,
12 : : const char namefmt[], ...);
13 : :
14 : : /**
15 : : * kthread_create - create a kthread on the current node
16 : : * @threadfn: the function to run in the thread
17 : : * @data: data pointer for @threadfn()
18 : : * @namefmt: printf-style format string for the thread name
19 : : * @arg...: arguments for @namefmt.
20 : : *
21 : : * This macro will create a kthread on the current node, leaving it in
22 : : * the stopped state. This is just a helper for kthread_create_on_node();
23 : : * see the documentation there for more details.
24 : : */
25 : : #define kthread_create(threadfn, data, namefmt, arg...) \
26 : : kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
27 : :
28 : :
29 : : struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
30 : : void *data,
31 : : unsigned int cpu,
32 : : const char *namefmt);
33 : :
34 : : /**
35 : : * kthread_run - create and wake a thread.
36 : : * @threadfn: the function to run until signal_pending(current).
37 : : * @data: data ptr for @threadfn.
38 : : * @namefmt: printf-style name for the thread.
39 : : *
40 : : * Description: Convenient wrapper for kthread_create() followed by
41 : : * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
42 : : */
43 : : #define kthread_run(threadfn, data, namefmt, ...) \
44 : : ({ \
45 : : struct task_struct *__k \
46 : : = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
47 : : if (!IS_ERR(__k)) \
48 : : wake_up_process(__k); \
49 : : __k; \
50 : : })
51 : :
52 : : void free_kthread_struct(struct task_struct *k);
53 : : void kthread_bind(struct task_struct *k, unsigned int cpu);
54 : : void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
55 : : int kthread_stop(struct task_struct *k);
56 : : bool kthread_should_stop(void);
57 : : bool kthread_should_park(void);
58 : : bool __kthread_should_park(struct task_struct *k);
59 : : bool kthread_freezable_should_stop(bool *was_frozen);
60 : : void *kthread_data(struct task_struct *k);
61 : : void *kthread_probe_data(struct task_struct *k);
62 : : int kthread_park(struct task_struct *k);
63 : : void kthread_unpark(struct task_struct *k);
64 : : void kthread_parkme(void);
65 : :
66 : : int kthreadd(void *unused);
67 : : extern struct task_struct *kthreadd_task;
68 : : extern int tsk_fork_get_node(struct task_struct *tsk);
69 : :
70 : : /*
71 : : * Simple work processor based on kthread.
72 : : *
73 : : * This provides easier way to make use of kthreads. A kthread_work
74 : : * can be queued and flushed using queue/kthread_flush_work()
75 : : * respectively. Queued kthread_works are processed by a kthread
76 : : * running kthread_worker_fn().
77 : : */
78 : : struct kthread_work;
79 : : typedef void (*kthread_work_func_t)(struct kthread_work *work);
80 : : void kthread_delayed_work_timer_fn(struct timer_list *t);
81 : :
82 : : enum {
83 : : KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
84 : : };
85 : :
86 : : struct kthread_worker {
87 : : unsigned int flags;
88 : : raw_spinlock_t lock;
89 : : struct list_head work_list;
90 : : struct list_head delayed_work_list;
91 : : struct task_struct *task;
92 : : struct kthread_work *current_work;
93 : : };
94 : :
95 : : struct kthread_work {
96 : : struct list_head node;
97 : : kthread_work_func_t func;
98 : : struct kthread_worker *worker;
99 : : /* Number of canceling calls that are running at the moment. */
100 : : int canceling;
101 : : };
102 : :
103 : : struct kthread_delayed_work {
104 : : struct kthread_work work;
105 : : struct timer_list timer;
106 : : };
107 : :
108 : : #define KTHREAD_WORKER_INIT(worker) { \
109 : : .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \
110 : : .work_list = LIST_HEAD_INIT((worker).work_list), \
111 : : .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
112 : : }
113 : :
114 : : #define KTHREAD_WORK_INIT(work, fn) { \
115 : : .node = LIST_HEAD_INIT((work).node), \
116 : : .func = (fn), \
117 : : }
118 : :
119 : : #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
120 : : .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
121 : : .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
122 : : TIMER_IRQSAFE), \
123 : : }
124 : :
125 : : #define DEFINE_KTHREAD_WORKER(worker) \
126 : : struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
127 : :
128 : : #define DEFINE_KTHREAD_WORK(work, fn) \
129 : : struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
130 : :
131 : : #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
132 : : struct kthread_delayed_work dwork = \
133 : : KTHREAD_DELAYED_WORK_INIT(dwork, fn)
134 : :
135 : : /*
136 : : * kthread_worker.lock needs its own lockdep class key when defined on
137 : : * stack with lockdep enabled. Use the following macros in such cases.
138 : : */
139 : : #ifdef CONFIG_LOCKDEP
140 : : # define KTHREAD_WORKER_INIT_ONSTACK(worker) \
141 : : ({ kthread_init_worker(&worker); worker; })
142 : : # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
143 : : struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
144 : : #else
145 : : # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
146 : : #endif
147 : :
148 : : extern void __kthread_init_worker(struct kthread_worker *worker,
149 : : const char *name, struct lock_class_key *key);
150 : :
151 : : #define kthread_init_worker(worker) \
152 : : do { \
153 : : static struct lock_class_key __key; \
154 : : __kthread_init_worker((worker), "("#worker")->lock", &__key); \
155 : : } while (0)
156 : :
157 : : #define kthread_init_work(work, fn) \
158 : : do { \
159 : : memset((work), 0, sizeof(struct kthread_work)); \
160 : : INIT_LIST_HEAD(&(work)->node); \
161 : : (work)->func = (fn); \
162 : : } while (0)
163 : :
164 : : #define kthread_init_delayed_work(dwork, fn) \
165 : : do { \
166 : : kthread_init_work(&(dwork)->work, (fn)); \
167 : : timer_setup(&(dwork)->timer, \
168 : : kthread_delayed_work_timer_fn, 0); \
169 : : } while (0)
170 : :
171 : : int kthread_worker_fn(void *worker_ptr);
172 : :
173 : : __printf(2, 3)
174 : : struct kthread_worker *
175 : : kthread_create_worker(unsigned int flags, const char namefmt[], ...);
176 : :
177 : : __printf(3, 4) struct kthread_worker *
178 : : kthread_create_worker_on_cpu(int cpu, unsigned int flags,
179 : : const char namefmt[], ...);
180 : :
181 : : bool kthread_queue_work(struct kthread_worker *worker,
182 : : struct kthread_work *work);
183 : :
184 : : bool kthread_queue_delayed_work(struct kthread_worker *worker,
185 : : struct kthread_delayed_work *dwork,
186 : : unsigned long delay);
187 : :
188 : : bool kthread_mod_delayed_work(struct kthread_worker *worker,
189 : : struct kthread_delayed_work *dwork,
190 : : unsigned long delay);
191 : :
192 : : void kthread_flush_work(struct kthread_work *work);
193 : : void kthread_flush_worker(struct kthread_worker *worker);
194 : :
195 : : bool kthread_cancel_work_sync(struct kthread_work *work);
196 : : bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
197 : :
198 : : void kthread_destroy_worker(struct kthread_worker *worker);
199 : :
200 : : struct cgroup_subsys_state;
201 : :
202 : : #ifdef CONFIG_BLK_CGROUP
203 : : void kthread_associate_blkcg(struct cgroup_subsys_state *css);
204 : : struct cgroup_subsys_state *kthread_blkcg(void);
205 : : #else
206 [ # # ]: 0 : static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
207 : : static inline struct cgroup_subsys_state *kthread_blkcg(void)
208 : : {
209 : : return NULL;
210 : : }
211 : : #endif
212 : : #endif /* _LINUX_KTHREAD_H */
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