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 get_kthread_comm(char *buf, size_t buf_size, struct task_struct *tsk); 37 bool set_kthread_struct(struct task_struct *p); 38 39 void kthread_set_per_cpu(struct task_struct *k, int cpu); 40 bool kthread_is_per_cpu(struct task_struct *k); 41 42 /** 43 * kthread_run - create and wake a thread. 44 * @threadfn: the function to run until signal_pending(current). 45 * @data: data ptr for @threadfn. 46 * @namefmt: printf-style name for the thread. 47 * 48 * Description: Convenient wrapper for kthread_create() followed by 49 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 50 */ 51 #define kthread_run(threadfn, data, namefmt, ...) \ 52 ({ \ 53 struct task_struct *__k \ 54 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 55 if (!IS_ERR(__k)) \ 56 wake_up_process(__k); \ 57 __k; \ 58 }) 59 60 /** 61 * kthread_run_on_cpu - create and wake a cpu bound thread. 62 * @threadfn: the function to run until signal_pending(current). 63 * @data: data ptr for @threadfn. 64 * @cpu: The cpu on which the thread should be bound, 65 * @namefmt: printf-style name for the thread. Format is restricted 66 * to "name.*%u". Code fills in cpu number. 67 * 68 * Description: Convenient wrapper for kthread_create_on_cpu() 69 * followed by wake_up_process(). Returns the kthread or 70 * ERR_PTR(-ENOMEM). 71 */ 72 static inline struct task_struct * 73 kthread_run_on_cpu(int (*threadfn)(void *data), void *data, 74 unsigned int cpu, const char *namefmt) 75 { 76 struct task_struct *p; 77 78 p = kthread_create_on_cpu(threadfn, data, cpu, namefmt); 79 if (!IS_ERR(p)) 80 wake_up_process(p); 81 82 return p; 83 } 84 85 void free_kthread_struct(struct task_struct *k); 86 void kthread_bind(struct task_struct *k, unsigned int cpu); 87 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); 88 int kthread_affine_preferred(struct task_struct *p, const struct cpumask *mask); 89 int kthread_stop(struct task_struct *k); 90 int kthread_stop_put(struct task_struct *k); 91 bool kthread_should_stop(void); 92 bool kthread_should_park(void); 93 bool kthread_should_stop_or_park(void); 94 bool kthread_freezable_should_stop(bool *was_frozen); 95 void *kthread_func(struct task_struct *k); 96 void *kthread_data(struct task_struct *k); 97 void *kthread_probe_data(struct task_struct *k); 98 int kthread_park(struct task_struct *k); 99 void kthread_unpark(struct task_struct *k); 100 void kthread_parkme(void); 101 void kthread_exit(long result) __noreturn; 102 void kthread_complete_and_exit(struct completion *, long) __noreturn; 103 104 int kthreadd(void *unused); 105 extern struct task_struct *kthreadd_task; 106 extern int tsk_fork_get_node(struct task_struct *tsk); 107 108 /* 109 * Simple work processor based on kthread. 110 * 111 * This provides easier way to make use of kthreads. A kthread_work 112 * can be queued and flushed using queue/kthread_flush_work() 113 * respectively. Queued kthread_works are processed by a kthread 114 * running kthread_worker_fn(). 115 */ 116 struct kthread_work; 117 typedef void (*kthread_work_func_t)(struct kthread_work *work); 118 void kthread_delayed_work_timer_fn(struct timer_list *t); 119 120 enum { 121 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 122 }; 123 124 struct kthread_worker { 125 unsigned int flags; 126 raw_spinlock_t lock; 127 struct list_head work_list; 128 struct list_head delayed_work_list; 129 struct task_struct *task; 130 struct kthread_work *current_work; 131 }; 132 133 struct kthread_work { 134 struct list_head node; 135 kthread_work_func_t func; 136 struct kthread_worker *worker; 137 /* Number of canceling calls that are running at the moment. */ 138 int canceling; 139 }; 140 141 struct kthread_delayed_work { 142 struct kthread_work work; 143 struct timer_list timer; 144 }; 145 146 #define KTHREAD_WORK_INIT(work, fn) { \ 147 .node = LIST_HEAD_INIT((work).node), \ 148 .func = (fn), \ 149 } 150 151 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 152 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 153 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\ 154 TIMER_IRQSAFE), \ 155 } 156 157 #define DEFINE_KTHREAD_WORK(work, fn) \ 158 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 159 160 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ 161 struct kthread_delayed_work dwork = \ 162 KTHREAD_DELAYED_WORK_INIT(dwork, fn) 163 164 extern void __kthread_init_worker(struct kthread_worker *worker, 165 const char *name, struct lock_class_key *key); 166 167 #define kthread_init_worker(worker) \ 168 do { \ 169 static struct lock_class_key __key; \ 170 __kthread_init_worker((worker), "("#worker")->lock", &__key); \ 171 } while (0) 172 173 #define kthread_init_work(work, fn) \ 174 do { \ 175 memset((work), 0, sizeof(struct kthread_work)); \ 176 INIT_LIST_HEAD(&(work)->node); \ 177 (work)->func = (fn); \ 178 } while (0) 179 180 #define kthread_init_delayed_work(dwork, fn) \ 181 do { \ 182 kthread_init_work(&(dwork)->work, (fn)); \ 183 timer_setup(&(dwork)->timer, \ 184 kthread_delayed_work_timer_fn, \ 185 TIMER_IRQSAFE); \ 186 } while (0) 187 188 int kthread_worker_fn(void *worker_ptr); 189 190 __printf(3, 4) 191 struct kthread_worker *kthread_create_worker_on_node(unsigned int flags, 192 int node, 193 const char namefmt[], ...); 194 195 #define kthread_create_worker(flags, namefmt, ...) \ 196 kthread_create_worker_on_node(flags, NUMA_NO_NODE, namefmt, ## __VA_ARGS__); 197 198 /** 199 * kthread_run_worker - create and wake a kthread worker. 200 * @flags: flags modifying the default behavior of the worker 201 * @namefmt: printf-style name for the thread. 202 * 203 * Description: Convenient wrapper for kthread_create_worker() followed by 204 * wake_up_process(). Returns the kthread_worker or ERR_PTR(-ENOMEM). 205 */ 206 #define kthread_run_worker(flags, namefmt, ...) \ 207 ({ \ 208 struct kthread_worker *__kw \ 209 = kthread_create_worker(flags, namefmt, ## __VA_ARGS__); \ 210 if (!IS_ERR(__kw)) \ 211 wake_up_process(__kw->task); \ 212 __kw; \ 213 }) 214 215 struct kthread_worker * 216 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 217 const char namefmt[]); 218 219 /** 220 * kthread_run_worker_on_cpu - create and wake a cpu bound kthread worker. 221 * @cpu: CPU number 222 * @flags: flags modifying the default behavior of the worker 223 * @namefmt: printf-style name for the thread. Format is restricted 224 * to "name.*%u". Code fills in cpu number. 225 * 226 * Description: Convenient wrapper for kthread_create_worker_on_cpu() 227 * followed by wake_up_process(). Returns the kthread_worker or 228 * ERR_PTR(-ENOMEM). 229 */ 230 static inline struct kthread_worker * 231 kthread_run_worker_on_cpu(int cpu, unsigned int flags, 232 const char namefmt[]) 233 { 234 struct kthread_worker *kw; 235 236 kw = kthread_create_worker_on_cpu(cpu, flags, namefmt); 237 if (!IS_ERR(kw)) 238 wake_up_process(kw->task); 239 240 return kw; 241 } 242 243 bool kthread_queue_work(struct kthread_worker *worker, 244 struct kthread_work *work); 245 246 bool kthread_queue_delayed_work(struct kthread_worker *worker, 247 struct kthread_delayed_work *dwork, 248 unsigned long delay); 249 250 bool kthread_mod_delayed_work(struct kthread_worker *worker, 251 struct kthread_delayed_work *dwork, 252 unsigned long delay); 253 254 void kthread_flush_work(struct kthread_work *work); 255 void kthread_flush_worker(struct kthread_worker *worker); 256 257 bool kthread_cancel_work_sync(struct kthread_work *work); 258 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 259 260 void kthread_destroy_worker(struct kthread_worker *worker); 261 262 void kthread_use_mm(struct mm_struct *mm); 263 void kthread_unuse_mm(struct mm_struct *mm); 264 265 struct cgroup_subsys_state; 266 267 #ifdef CONFIG_BLK_CGROUP 268 void kthread_associate_blkcg(struct cgroup_subsys_state *css); 269 struct cgroup_subsys_state *kthread_blkcg(void); 270 #else 271 static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } 272 #endif 273 #endif /* _LINUX_KTHREAD_H */ 274