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 bool 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 /** 60 * kthread_run_on_cpu - create and wake a cpu bound thread. 61 * @threadfn: the function to run until signal_pending(current). 62 * @data: data ptr for @threadfn. 63 * @cpu: The cpu on which the thread should be bound, 64 * @namefmt: printf-style name for the thread. Format is restricted 65 * to "name.*%u". Code fills in cpu number. 66 * 67 * Description: Convenient wrapper for kthread_create_on_cpu() 68 * followed by wake_up_process(). Returns the kthread or 69 * ERR_PTR(-ENOMEM). 70 */ 71 static inline struct task_struct * 72 kthread_run_on_cpu(int (*threadfn)(void *data), void *data, 73 unsigned int cpu, const char *namefmt) 74 { 75 struct task_struct *p; 76 77 p = kthread_create_on_cpu(threadfn, data, cpu, namefmt); 78 if (!IS_ERR(p)) 79 wake_up_process(p); 80 81 return p; 82 } 83 84 void free_kthread_struct(struct task_struct *k); 85 void kthread_bind(struct task_struct *k, unsigned int cpu); 86 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); 87 int kthread_stop(struct task_struct *k); 88 bool kthread_should_stop(void); 89 bool kthread_should_park(void); 90 bool __kthread_should_park(struct task_struct *k); 91 bool kthread_freezable_should_stop(bool *was_frozen); 92 void *kthread_func(struct task_struct *k); 93 void *kthread_data(struct task_struct *k); 94 void *kthread_probe_data(struct task_struct *k); 95 int kthread_park(struct task_struct *k); 96 void kthread_unpark(struct task_struct *k); 97 void kthread_parkme(void); 98 void kthread_exit(long result) __noreturn; 99 void kthread_complete_and_exit(struct completion *, long) __noreturn; 100 101 int kthreadd(void *unused); 102 extern struct task_struct *kthreadd_task; 103 extern int tsk_fork_get_node(struct task_struct *tsk); 104 105 /* 106 * Simple work processor based on kthread. 107 * 108 * This provides easier way to make use of kthreads. A kthread_work 109 * can be queued and flushed using queue/kthread_flush_work() 110 * respectively. Queued kthread_works are processed by a kthread 111 * running kthread_worker_fn(). 112 */ 113 struct kthread_work; 114 typedef void (*kthread_work_func_t)(struct kthread_work *work); 115 void kthread_delayed_work_timer_fn(struct timer_list *t); 116 117 enum { 118 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 119 }; 120 121 struct kthread_worker { 122 unsigned int flags; 123 raw_spinlock_t lock; 124 struct list_head work_list; 125 struct list_head delayed_work_list; 126 struct task_struct *task; 127 struct kthread_work *current_work; 128 }; 129 130 struct kthread_work { 131 struct list_head node; 132 kthread_work_func_t func; 133 struct kthread_worker *worker; 134 /* Number of canceling calls that are running at the moment. */ 135 int canceling; 136 }; 137 138 struct kthread_delayed_work { 139 struct kthread_work work; 140 struct timer_list timer; 141 }; 142 143 #define KTHREAD_WORKER_INIT(worker) { \ 144 .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ 145 .work_list = LIST_HEAD_INIT((worker).work_list), \ 146 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ 147 } 148 149 #define KTHREAD_WORK_INIT(work, fn) { \ 150 .node = LIST_HEAD_INIT((work).node), \ 151 .func = (fn), \ 152 } 153 154 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 155 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 156 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\ 157 TIMER_IRQSAFE), \ 158 } 159 160 #define DEFINE_KTHREAD_WORKER(worker) \ 161 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 162 163 #define DEFINE_KTHREAD_WORK(work, fn) \ 164 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 165 166 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ 167 struct kthread_delayed_work dwork = \ 168 KTHREAD_DELAYED_WORK_INIT(dwork, fn) 169 170 /* 171 * kthread_worker.lock needs its own lockdep class key when defined on 172 * stack with lockdep enabled. Use the following macros in such cases. 173 */ 174 #ifdef CONFIG_LOCKDEP 175 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 176 ({ kthread_init_worker(&worker); worker; }) 177 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 178 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 179 #else 180 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 181 #endif 182 183 extern void __kthread_init_worker(struct kthread_worker *worker, 184 const char *name, struct lock_class_key *key); 185 186 #define kthread_init_worker(worker) \ 187 do { \ 188 static struct lock_class_key __key; \ 189 __kthread_init_worker((worker), "("#worker")->lock", &__key); \ 190 } while (0) 191 192 #define kthread_init_work(work, fn) \ 193 do { \ 194 memset((work), 0, sizeof(struct kthread_work)); \ 195 INIT_LIST_HEAD(&(work)->node); \ 196 (work)->func = (fn); \ 197 } while (0) 198 199 #define kthread_init_delayed_work(dwork, fn) \ 200 do { \ 201 kthread_init_work(&(dwork)->work, (fn)); \ 202 timer_setup(&(dwork)->timer, \ 203 kthread_delayed_work_timer_fn, \ 204 TIMER_IRQSAFE); \ 205 } while (0) 206 207 int kthread_worker_fn(void *worker_ptr); 208 209 __printf(2, 3) 210 struct kthread_worker * 211 kthread_create_worker(unsigned int flags, const char namefmt[], ...); 212 213 __printf(3, 4) struct kthread_worker * 214 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 215 const char namefmt[], ...); 216 217 bool kthread_queue_work(struct kthread_worker *worker, 218 struct kthread_work *work); 219 220 bool kthread_queue_delayed_work(struct kthread_worker *worker, 221 struct kthread_delayed_work *dwork, 222 unsigned long delay); 223 224 bool kthread_mod_delayed_work(struct kthread_worker *worker, 225 struct kthread_delayed_work *dwork, 226 unsigned long delay); 227 228 void kthread_flush_work(struct kthread_work *work); 229 void kthread_flush_worker(struct kthread_worker *worker); 230 231 bool kthread_cancel_work_sync(struct kthread_work *work); 232 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 233 234 void kthread_destroy_worker(struct kthread_worker *worker); 235 236 void kthread_use_mm(struct mm_struct *mm); 237 void kthread_unuse_mm(struct mm_struct *mm); 238 239 struct cgroup_subsys_state; 240 241 #ifdef CONFIG_BLK_CGROUP 242 void kthread_associate_blkcg(struct cgroup_subsys_state *css); 243 struct cgroup_subsys_state *kthread_blkcg(void); 244 #else 245 static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } 246 static inline struct cgroup_subsys_state *kthread_blkcg(void) 247 { 248 return NULL; 249 } 250 #endif 251 #endif /* _LINUX_KTHREAD_H */ 252