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 /**
37 * kthread_run - create and wake a thread.
38 * @threadfn: the function to run until signal_pending(current).
39 * @data: data ptr for @threadfn.
40 * @namefmt: printf-style name for the thread.
41 *
42 * Description: Convenient wrapper for kthread_create() followed by
43 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM).
44 */
45 #define kthread_run(threadfn, data, namefmt, ...) \
46 ({ \
47 struct task_struct *__k \
48 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
49 if (!IS_ERR(__k)) \
50 wake_up_process(__k); \
51 __k; \
52 })
53
54 void free_kthread_struct(struct task_struct *k);
55 void kthread_bind(struct task_struct *k, unsigned int cpu);
56 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
57 int kthread_stop(struct task_struct *k);
58 bool kthread_should_stop(void);
59 bool kthread_should_park(void);
60 bool __kthread_should_park(struct task_struct *k);
61 bool kthread_freezable_should_stop(bool *was_frozen);
62 void *kthread_func(struct task_struct *k);
63 void *kthread_data(struct task_struct *k);
64 void *kthread_probe_data(struct task_struct *k);
65 int kthread_park(struct task_struct *k);
66 void kthread_unpark(struct task_struct *k);
67 void kthread_parkme(void);
68
69 int kthreadd(void *unused);
70 extern struct task_struct *kthreadd_task;
71 extern int tsk_fork_get_node(struct task_struct *tsk);
72
73 /*
74 * Simple work processor based on kthread.
75 *
76 * This provides easier way to make use of kthreads. A kthread_work
77 * can be queued and flushed using queue/kthread_flush_work()
78 * respectively. Queued kthread_works are processed by a kthread
79 * running kthread_worker_fn().
80 */
81 struct kthread_work;
82 typedef void (*kthread_work_func_t)(struct kthread_work *work);
83 void kthread_delayed_work_timer_fn(struct timer_list *t);
84
85 enum {
86 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */
87 };
88
89 struct kthread_worker {
90 unsigned int flags;
91 raw_spinlock_t lock;
92 struct list_head work_list;
93 struct list_head delayed_work_list;
94 struct task_struct *task;
95 struct kthread_work *current_work;
96 };
97
98 struct kthread_work {
99 struct list_head node;
100 kthread_work_func_t func;
101 struct kthread_worker *worker;
102 /* Number of canceling calls that are running at the moment. */
103 int canceling;
104 };
105
106 struct kthread_delayed_work {
107 struct kthread_work work;
108 struct timer_list timer;
109 };
110
111 #define KTHREAD_WORKER_INIT(worker) { \
112 .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \
113 .work_list = LIST_HEAD_INIT((worker).work_list), \
114 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
115 }
116
117 #define KTHREAD_WORK_INIT(work, fn) { \
118 .node = LIST_HEAD_INIT((work).node), \
119 .func = (fn), \
120 }
121
122 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
123 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \
124 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\
125 TIMER_IRQSAFE), \
126 }
127
128 #define DEFINE_KTHREAD_WORKER(worker) \
129 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
130
131 #define DEFINE_KTHREAD_WORK(work, fn) \
132 struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
133
134 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \
135 struct kthread_delayed_work dwork = \
136 KTHREAD_DELAYED_WORK_INIT(dwork, fn)
137
138 /*
139 * kthread_worker.lock needs its own lockdep class key when defined on
140 * stack with lockdep enabled. Use the following macros in such cases.
141 */
142 #ifdef CONFIG_LOCKDEP
143 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \
144 ({ kthread_init_worker(&worker); worker; })
145 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \
146 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
147 #else
148 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
149 #endif
150
151 extern void __kthread_init_worker(struct kthread_worker *worker,
152 const char *name, struct lock_class_key *key);
153
154 #define kthread_init_worker(worker) \
155 do { \
156 static struct lock_class_key __key; \
157 __kthread_init_worker((worker), "("#worker")->lock", &__key); \
158 } while (0)
159
160 #define kthread_init_work(work, fn) \
161 do { \
162 memset((work), 0, sizeof(struct kthread_work)); \
163 INIT_LIST_HEAD(&(work)->node); \
164 (work)->func = (fn); \
165 } while (0)
166
167 #define kthread_init_delayed_work(dwork, fn) \
168 do { \
169 kthread_init_work(&(dwork)->work, (fn)); \
170 timer_setup(&(dwork)->timer, \
171 kthread_delayed_work_timer_fn, \
172 TIMER_IRQSAFE); \
173 } while (0)
174
175 int kthread_worker_fn(void *worker_ptr);
176
177 __printf(2, 3)
178 struct kthread_worker *
179 kthread_create_worker(unsigned int flags, const char namefmt[], ...);
180
181 __printf(3, 4) struct kthread_worker *
182 kthread_create_worker_on_cpu(int cpu, unsigned int flags,
183 const char namefmt[], ...);
184
185 bool kthread_queue_work(struct kthread_worker *worker,
186 struct kthread_work *work);
187
188 bool kthread_queue_delayed_work(struct kthread_worker *worker,
189 struct kthread_delayed_work *dwork,
190 unsigned long delay);
191
192 bool kthread_mod_delayed_work(struct kthread_worker *worker,
193 struct kthread_delayed_work *dwork,
194 unsigned long delay);
195
196 void kthread_flush_work(struct kthread_work *work);
197 void kthread_flush_worker(struct kthread_worker *worker);
198
199 bool kthread_cancel_work_sync(struct kthread_work *work);
200 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
201
202 void kthread_destroy_worker(struct kthread_worker *worker);
203
204 void kthread_use_mm(struct mm_struct *mm);
205 void kthread_unuse_mm(struct mm_struct *mm);
206
207 struct cgroup_subsys_state;
208
209 #ifdef CONFIG_BLK_CGROUP
210 void kthread_associate_blkcg(struct cgroup_subsys_state *css);
211 struct cgroup_subsys_state *kthread_blkcg(void);
212 #else
kthread_associate_blkcg(struct cgroup_subsys_state * css)213 static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
kthread_blkcg(void)214 static inline struct cgroup_subsys_state *kthread_blkcg(void)
215 {
216 return NULL;
217 }
218 #endif
219 #endif /* _LINUX_KTHREAD_H */
220
