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_freezable_should_stop(bool *was_frozen); 59 void *kthread_data(struct task_struct *k); 60 void *kthread_probe_data(struct task_struct *k); 61 int kthread_park(struct task_struct *k); 62 void kthread_unpark(struct task_struct *k); 63 void kthread_parkme(void); 64 65 int kthreadd(void *unused); 66 extern struct task_struct *kthreadd_task; 67 extern int tsk_fork_get_node(struct task_struct *tsk); 68 69 /* 70 * Simple work processor based on kthread. 71 * 72 * This provides easier way to make use of kthreads. A kthread_work 73 * can be queued and flushed using queue/kthread_flush_work() 74 * respectively. Queued kthread_works are processed by a kthread 75 * running kthread_worker_fn(). 76 */ 77 struct kthread_work; 78 typedef void (*kthread_work_func_t)(struct kthread_work *work); 79 void kthread_delayed_work_timer_fn(unsigned long __data); 80 81 enum { 82 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 83 }; 84 85 struct kthread_worker { 86 unsigned int flags; 87 spinlock_t lock; 88 struct list_head work_list; 89 struct list_head delayed_work_list; 90 struct task_struct *task; 91 struct kthread_work *current_work; 92 }; 93 94 struct kthread_work { 95 struct list_head node; 96 kthread_work_func_t func; 97 struct kthread_worker *worker; 98 /* Number of canceling calls that are running at the moment. */ 99 int canceling; 100 }; 101 102 struct kthread_delayed_work { 103 struct kthread_work work; 104 struct timer_list timer; 105 }; 106 107 #define KTHREAD_WORKER_INIT(worker) { \ 108 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ 109 .work_list = LIST_HEAD_INIT((worker).work_list), \ 110 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ 111 } 112 113 #define KTHREAD_WORK_INIT(work, fn) { \ 114 .node = LIST_HEAD_INIT((work).node), \ 115 .func = (fn), \ 116 } 117 118 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 119 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 120 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn, \ 121 0, (unsigned long)&(dwork), \ 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 __setup_timer(&(dwork)->timer, \ 168 kthread_delayed_work_timer_fn, \ 169 (unsigned long)(dwork), \ 170 TIMER_IRQSAFE); \ 171 } while (0) 172 173 int kthread_worker_fn(void *worker_ptr); 174 175 __printf(2, 3) 176 struct kthread_worker * 177 kthread_create_worker(unsigned int flags, const char namefmt[], ...); 178 179 __printf(3, 4) struct kthread_worker * 180 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 181 const char namefmt[], ...); 182 183 bool kthread_queue_work(struct kthread_worker *worker, 184 struct kthread_work *work); 185 186 bool kthread_queue_delayed_work(struct kthread_worker *worker, 187 struct kthread_delayed_work *dwork, 188 unsigned long delay); 189 190 bool kthread_mod_delayed_work(struct kthread_worker *worker, 191 struct kthread_delayed_work *dwork, 192 unsigned long delay); 193 194 void kthread_flush_work(struct kthread_work *work); 195 void kthread_flush_worker(struct kthread_worker *worker); 196 197 bool kthread_cancel_work_sync(struct kthread_work *work); 198 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 199 200 void kthread_destroy_worker(struct kthread_worker *worker); 201 202 #endif /* _LINUX_KTHREAD_H */ 203