| 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_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 | 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 = __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 | __init_timer(&(dwork)->timer, \ |
| 168 | kthread_delayed_work_timer_fn, \ |
| 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 | #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 */ |