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 | #include <linux/cgroup.h> |
8 | |
9 | __printf(4, 5) |
10 | struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), |
11 | void *data, |
12 | int node, |
13 | const char namefmt[], ...); |
14 | |
15 | /** |
16 | * kthread_create - create a kthread on the current node |
17 | * @threadfn: the function to run in the thread |
18 | * @data: data pointer for @threadfn() |
19 | * @namefmt: printf-style format string for the thread name |
20 | * @arg...: arguments for @namefmt. |
21 | * |
22 | * This macro will create a kthread on the current node, leaving it in |
23 | * the stopped state. This is just a helper for kthread_create_on_node(); |
24 | * see the documentation there for more details. |
25 | */ |
26 | #define kthread_create(threadfn, data, namefmt, arg...) \ |
27 | kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg) |
28 | |
29 | |
30 | struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), |
31 | void *data, |
32 | unsigned int cpu, |
33 | const char *namefmt); |
34 | |
35 | /** |
36 | * kthread_run - create and wake a thread. |
37 | * @threadfn: the function to run until signal_pending(current). |
38 | * @data: data ptr for @threadfn. |
39 | * @namefmt: printf-style name for the thread. |
40 | * |
41 | * Description: Convenient wrapper for kthread_create() followed by |
42 | * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). |
43 | */ |
44 | #define kthread_run(threadfn, data, namefmt, ...) \ |
45 | ({ \ |
46 | struct task_struct *__k \ |
47 | = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ |
48 | if (!IS_ERR(__k)) \ |
49 | wake_up_process(__k); \ |
50 | __k; \ |
51 | }) |
52 | |
53 | void free_kthread_struct(struct task_struct *k); |
54 | void kthread_bind(struct task_struct *k, unsigned int cpu); |
55 | void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); |
56 | int kthread_stop(struct task_struct *k); |
57 | bool kthread_should_stop(void); |
58 | bool kthread_should_park(void); |
59 | bool __kthread_should_park(struct task_struct *k); |
60 | bool kthread_freezable_should_stop(bool *was_frozen); |
61 | void *kthread_data(struct task_struct *k); |
62 | void *kthread_probe_data(struct task_struct *k); |
63 | int kthread_park(struct task_struct *k); |
64 | void kthread_unpark(struct task_struct *k); |
65 | void kthread_parkme(void); |
66 | |
67 | int kthreadd(void *unused); |
68 | extern struct task_struct *kthreadd_task; |
69 | extern int tsk_fork_get_node(struct task_struct *tsk); |
70 | |
71 | /* |
72 | * Simple work processor based on kthread. |
73 | * |
74 | * This provides easier way to make use of kthreads. A kthread_work |
75 | * can be queued and flushed using queue/kthread_flush_work() |
76 | * respectively. Queued kthread_works are processed by a kthread |
77 | * running kthread_worker_fn(). |
78 | */ |
79 | struct kthread_work; |
80 | typedef void (*kthread_work_func_t)(struct kthread_work *work); |
81 | void kthread_delayed_work_timer_fn(struct timer_list *t); |
82 | |
83 | enum { |
84 | KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ |
85 | }; |
86 | |
87 | struct kthread_worker { |
88 | unsigned int flags; |
89 | raw_spinlock_t lock; |
90 | struct list_head work_list; |
91 | struct list_head delayed_work_list; |
92 | struct task_struct *task; |
93 | struct kthread_work *current_work; |
94 | }; |
95 | |
96 | struct kthread_work { |
97 | struct list_head node; |
98 | kthread_work_func_t func; |
99 | struct kthread_worker *worker; |
100 | /* Number of canceling calls that are running at the moment. */ |
101 | int canceling; |
102 | }; |
103 | |
104 | struct kthread_delayed_work { |
105 | struct kthread_work work; |
106 | struct timer_list timer; |
107 | }; |
108 | |
109 | #define KTHREAD_WORKER_INIT(worker) { \ |
110 | .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ |
111 | .work_list = LIST_HEAD_INIT((worker).work_list), \ |
112 | .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ |
113 | } |
114 | |
115 | #define KTHREAD_WORK_INIT(work, fn) { \ |
116 | .node = LIST_HEAD_INIT((work).node), \ |
117 | .func = (fn), \ |
118 | } |
119 | |
120 | #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ |
121 | .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ |
122 | .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\ |
123 | TIMER_IRQSAFE), \ |
124 | } |
125 | |
126 | #define DEFINE_KTHREAD_WORKER(worker) \ |
127 | struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) |
128 | |
129 | #define DEFINE_KTHREAD_WORK(work, fn) \ |
130 | struct kthread_work work = KTHREAD_WORK_INIT(work, fn) |
131 | |
132 | #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ |
133 | struct kthread_delayed_work dwork = \ |
134 | KTHREAD_DELAYED_WORK_INIT(dwork, fn) |
135 | |
136 | /* |
137 | * kthread_worker.lock needs its own lockdep class key when defined on |
138 | * stack with lockdep enabled. Use the following macros in such cases. |
139 | */ |
140 | #ifdef CONFIG_LOCKDEP |
141 | # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ |
142 | ({ kthread_init_worker(&worker); worker; }) |
143 | # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ |
144 | struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) |
145 | #else |
146 | # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) |
147 | #endif |
148 | |
149 | extern void __kthread_init_worker(struct kthread_worker *worker, |
150 | const char *name, struct lock_class_key *key); |
151 | |
152 | #define kthread_init_worker(worker) \ |
153 | do { \ |
154 | static struct lock_class_key __key; \ |
155 | __kthread_init_worker((worker), "("#worker")->lock", &__key); \ |
156 | } while (0) |
157 | |
158 | #define kthread_init_work(work, fn) \ |
159 | do { \ |
160 | memset((work), 0, sizeof(struct kthread_work)); \ |
161 | INIT_LIST_HEAD(&(work)->node); \ |
162 | (work)->func = (fn); \ |
163 | } while (0) |
164 | |
165 | #define kthread_init_delayed_work(dwork, fn) \ |
166 | do { \ |
167 | kthread_init_work(&(dwork)->work, (fn)); \ |
168 | timer_setup(&(dwork)->timer, \ |
169 | kthread_delayed_work_timer_fn, 0); \ |
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 | #ifdef CONFIG_BLK_CGROUP |
202 | void kthread_associate_blkcg(struct cgroup_subsys_state *css); |
203 | struct cgroup_subsys_state *kthread_blkcg(void); |
204 | #else |
205 | static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } |
206 | static inline struct cgroup_subsys_state *kthread_blkcg(void) |
207 | { |
208 | return NULL; |
209 | } |
210 | #endif |
211 | #endif /* _LINUX_KTHREAD_H */ |
212 | |