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 /** 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 99 int kthreadd(void *unused); 100 extern struct task_struct *kthreadd_task; 101 extern int tsk_fork_get_node(struct task_struct *tsk); 102 103 /* 104 * Simple work processor based on kthread. 105 * 106 * This provides easier way to make use of kthreads. A kthread_work 107 * can be queued and flushed using queue/kthread_flush_work() 108 * respectively. Queued kthread_works are processed by a kthread 109 * running kthread_worker_fn(). 110 */ 111 struct kthread_work; 112 typedef void (*kthread_work_func_t)(struct kthread_work *work); 113 void kthread_delayed_work_timer_fn(struct timer_list *t); 114 115 enum { 116 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 117 }; 118 119 struct kthread_worker { 120 unsigned int flags; 121 raw_spinlock_t lock; 122 struct list_head work_list; 123 struct list_head delayed_work_list; 124 struct task_struct *task; 125 struct kthread_work *current_work; 126 }; 127 128 struct kthread_work { 129 struct list_head node; 130 kthread_work_func_t func; 131 struct kthread_worker *worker; 132 /* Number of canceling calls that are running at the moment. */ 133 int canceling; 134 }; 135 136 struct kthread_delayed_work { 137 struct kthread_work work; 138 struct timer_list timer; 139 }; 140 141 #define KTHREAD_WORKER_INIT(worker) { \ 142 .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ 143 .work_list = LIST_HEAD_INIT((worker).work_list), \ 144 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ 145 } 146 147 #define KTHREAD_WORK_INIT(work, fn) { \ 148 .node = LIST_HEAD_INIT((work).node), \ 149 .func = (fn), \ 150 } 151 152 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 153 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 154 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\ 155 TIMER_IRQSAFE), \ 156 } 157 158 #define DEFINE_KTHREAD_WORKER(worker) \ 159 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 160 161 #define DEFINE_KTHREAD_WORK(work, fn) \ 162 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 163 164 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ 165 struct kthread_delayed_work dwork = \ 166 KTHREAD_DELAYED_WORK_INIT(dwork, fn) 167 168 /* 169 * kthread_worker.lock needs its own lockdep class key when defined on 170 * stack with lockdep enabled. Use the following macros in such cases. 171 */ 172 #ifdef CONFIG_LOCKDEP 173 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 174 ({ kthread_init_worker(&worker); worker; }) 175 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 176 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 177 #else 178 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 179 #endif 180 181 extern void __kthread_init_worker(struct kthread_worker *worker, 182 const char *name, struct lock_class_key *key); 183 184 #define kthread_init_worker(worker) \ 185 do { \ 186 static struct lock_class_key __key; \ 187 __kthread_init_worker((worker), "("#worker")->lock", &__key); \ 188 } while (0) 189 190 #define kthread_init_work(work, fn) \ 191 do { \ 192 memset((work), 0, sizeof(struct kthread_work)); \ 193 INIT_LIST_HEAD(&(work)->node); \ 194 (work)->func = (fn); \ 195 } while (0) 196 197 #define kthread_init_delayed_work(dwork, fn) \ 198 do { \ 199 kthread_init_work(&(dwork)->work, (fn)); \ 200 timer_setup(&(dwork)->timer, \ 201 kthread_delayed_work_timer_fn, \ 202 TIMER_IRQSAFE); \ 203 } while (0) 204 205 int kthread_worker_fn(void *worker_ptr); 206 207 __printf(2, 3) 208 struct kthread_worker * 209 kthread_create_worker(unsigned int flags, const char namefmt[], ...); 210 211 __printf(3, 4) struct kthread_worker * 212 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 213 const char namefmt[], ...); 214 215 bool kthread_queue_work(struct kthread_worker *worker, 216 struct kthread_work *work); 217 218 bool kthread_queue_delayed_work(struct kthread_worker *worker, 219 struct kthread_delayed_work *dwork, 220 unsigned long delay); 221 222 bool kthread_mod_delayed_work(struct kthread_worker *worker, 223 struct kthread_delayed_work *dwork, 224 unsigned long delay); 225 226 void kthread_flush_work(struct kthread_work *work); 227 void kthread_flush_worker(struct kthread_worker *worker); 228 229 bool kthread_cancel_work_sync(struct kthread_work *work); 230 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 231 232 void kthread_destroy_worker(struct kthread_worker *worker); 233 234 void kthread_use_mm(struct mm_struct *mm); 235 void kthread_unuse_mm(struct mm_struct *mm); 236 237 struct cgroup_subsys_state; 238 239 #ifdef CONFIG_BLK_CGROUP 240 void kthread_associate_blkcg(struct cgroup_subsys_state *css); 241 struct cgroup_subsys_state *kthread_blkcg(void); 242 #else 243 static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } 244 static inline struct cgroup_subsys_state *kthread_blkcg(void) 245 { 246 return NULL; 247 } 248 #endif 249 #endif /* _LINUX_KTHREAD_H */ 250