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