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 void set_kthread_struct(struct task_struct *p); 37 38 void kthread_set_per_cpu(struct task_struct *k, int cpu); 39 bool kthread_is_per_cpu(struct task_struct *k); 40 41 /** 42 * kthread_run - create and wake a thread. 43 * @threadfn: the function to run until signal_pending(current). 44 * @data: data ptr for @threadfn. 45 * @namefmt: printf-style name for the thread. 46 * 47 * Description: Convenient wrapper for kthread_create() followed by 48 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 49 */ 50 #define kthread_run(threadfn, data, namefmt, ...) \ 51 ({ \ 52 struct task_struct *__k \ 53 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 54 if (!IS_ERR(__k)) \ 55 wake_up_process(__k); \ 56 __k; \ 57 }) 58 59 void free_kthread_struct(struct task_struct *k); 60 void kthread_bind(struct task_struct *k, unsigned int cpu); 61 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); 62 int kthread_stop(struct task_struct *k); 63 bool kthread_should_stop(void); 64 bool kthread_should_park(void); 65 bool __kthread_should_park(struct task_struct *k); 66 bool kthread_freezable_should_stop(bool *was_frozen); 67 void *kthread_func(struct task_struct *k); 68 void *kthread_data(struct task_struct *k); 69 void *kthread_probe_data(struct task_struct *k); 70 int kthread_park(struct task_struct *k); 71 void kthread_unpark(struct task_struct *k); 72 void kthread_parkme(void); 73 void kthread_exit(long result) __noreturn; 74 75 int kthreadd(void *unused); 76 extern struct task_struct *kthreadd_task; 77 extern int tsk_fork_get_node(struct task_struct *tsk); 78 79 /* 80 * Simple work processor based on kthread. 81 * 82 * This provides easier way to make use of kthreads. A kthread_work 83 * can be queued and flushed using queue/kthread_flush_work() 84 * respectively. Queued kthread_works are processed by a kthread 85 * running kthread_worker_fn(). 86 */ 87 struct kthread_work; 88 typedef void (*kthread_work_func_t)(struct kthread_work *work); 89 void kthread_delayed_work_timer_fn(struct timer_list *t); 90 91 enum { 92 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 93 }; 94 95 struct kthread_worker { 96 unsigned int flags; 97 raw_spinlock_t lock; 98 struct list_head work_list; 99 struct list_head delayed_work_list; 100 struct task_struct *task; 101 struct kthread_work *current_work; 102 }; 103 104 struct kthread_work { 105 struct list_head node; 106 kthread_work_func_t func; 107 struct kthread_worker *worker; 108 /* Number of canceling calls that are running at the moment. */ 109 int canceling; 110 }; 111 112 struct kthread_delayed_work { 113 struct kthread_work work; 114 struct timer_list timer; 115 }; 116 117 #define KTHREAD_WORKER_INIT(worker) { \ 118 .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ 119 .work_list = LIST_HEAD_INIT((worker).work_list), \ 120 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ 121 } 122 123 #define KTHREAD_WORK_INIT(work, fn) { \ 124 .node = LIST_HEAD_INIT((work).node), \ 125 .func = (fn), \ 126 } 127 128 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 129 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 130 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\ 131 TIMER_IRQSAFE), \ 132 } 133 134 #define DEFINE_KTHREAD_WORKER(worker) \ 135 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 136 137 #define DEFINE_KTHREAD_WORK(work, fn) \ 138 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 139 140 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ 141 struct kthread_delayed_work dwork = \ 142 KTHREAD_DELAYED_WORK_INIT(dwork, fn) 143 144 /* 145 * kthread_worker.lock needs its own lockdep class key when defined on 146 * stack with lockdep enabled. Use the following macros in such cases. 147 */ 148 #ifdef CONFIG_LOCKDEP 149 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 150 ({ kthread_init_worker(&worker); worker; }) 151 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 152 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 153 #else 154 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 155 #endif 156 157 extern void __kthread_init_worker(struct kthread_worker *worker, 158 const char *name, struct lock_class_key *key); 159 160 #define kthread_init_worker(worker) \ 161 do { \ 162 static struct lock_class_key __key; \ 163 __kthread_init_worker((worker), "("#worker")->lock", &__key); \ 164 } while (0) 165 166 #define kthread_init_work(work, fn) \ 167 do { \ 168 memset((work), 0, sizeof(struct kthread_work)); \ 169 INIT_LIST_HEAD(&(work)->node); \ 170 (work)->func = (fn); \ 171 } while (0) 172 173 #define kthread_init_delayed_work(dwork, fn) \ 174 do { \ 175 kthread_init_work(&(dwork)->work, (fn)); \ 176 timer_setup(&(dwork)->timer, \ 177 kthread_delayed_work_timer_fn, \ 178 TIMER_IRQSAFE); \ 179 } while (0) 180 181 int kthread_worker_fn(void *worker_ptr); 182 183 __printf(2, 3) 184 struct kthread_worker * 185 kthread_create_worker(unsigned int flags, const char namefmt[], ...); 186 187 __printf(3, 4) struct kthread_worker * 188 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 189 const char namefmt[], ...); 190 191 bool kthread_queue_work(struct kthread_worker *worker, 192 struct kthread_work *work); 193 194 bool kthread_queue_delayed_work(struct kthread_worker *worker, 195 struct kthread_delayed_work *dwork, 196 unsigned long delay); 197 198 bool kthread_mod_delayed_work(struct kthread_worker *worker, 199 struct kthread_delayed_work *dwork, 200 unsigned long delay); 201 202 void kthread_flush_work(struct kthread_work *work); 203 void kthread_flush_worker(struct kthread_worker *worker); 204 205 bool kthread_cancel_work_sync(struct kthread_work *work); 206 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 207 208 void kthread_destroy_worker(struct kthread_worker *worker); 209 210 void kthread_use_mm(struct mm_struct *mm); 211 void kthread_unuse_mm(struct mm_struct *mm); 212 213 struct cgroup_subsys_state; 214 215 #ifdef CONFIG_BLK_CGROUP 216 void kthread_associate_blkcg(struct cgroup_subsys_state *css); 217 struct cgroup_subsys_state *kthread_blkcg(void); 218 #else 219 static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } 220 static inline struct cgroup_subsys_state *kthread_blkcg(void) 221 { 222 return NULL; 223 } 224 #endif 225 #endif /* _LINUX_KTHREAD_H */ 226