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 #include <linux/cgroup.h> 8 9 __printf(4, 5) 10 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), 11 void *data, 12 int node, 13 const char namefmt[], ...); 14 15 /** 16 * kthread_create - create a kthread on the current node 17 * @threadfn: the function to run in the thread 18 * @data: data pointer for @threadfn() 19 * @namefmt: printf-style format string for the thread name 20 * @arg...: arguments for @namefmt. 21 * 22 * This macro will create a kthread on the current node, leaving it in 23 * the stopped state. This is just a helper for kthread_create_on_node(); 24 * see the documentation there for more details. 25 */ 26 #define kthread_create(threadfn, data, namefmt, arg...) \ 27 kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg) 28 29 30 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), 31 void *data, 32 unsigned int cpu, 33 const char *namefmt); 34 35 /** 36 * kthread_run - create and wake a thread. 37 * @threadfn: the function to run until signal_pending(current). 38 * @data: data ptr for @threadfn. 39 * @namefmt: printf-style name for the thread. 40 * 41 * Description: Convenient wrapper for kthread_create() followed by 42 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 43 */ 44 #define kthread_run(threadfn, data, namefmt, ...) \ 45 ({ \ 46 struct task_struct *__k \ 47 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 48 if (!IS_ERR(__k)) \ 49 wake_up_process(__k); \ 50 __k; \ 51 }) 52 53 void free_kthread_struct(struct task_struct *k); 54 void kthread_bind(struct task_struct *k, unsigned int cpu); 55 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); 56 int kthread_stop(struct task_struct *k); 57 bool kthread_should_stop(void); 58 bool kthread_should_park(void); 59 bool __kthread_should_park(struct task_struct *k); 60 bool kthread_freezable_should_stop(bool *was_frozen); 61 void *kthread_data(struct task_struct *k); 62 void *kthread_probe_data(struct task_struct *k); 63 int kthread_park(struct task_struct *k); 64 void kthread_unpark(struct task_struct *k); 65 void kthread_parkme(void); 66 67 int kthreadd(void *unused); 68 extern struct task_struct *kthreadd_task; 69 extern int tsk_fork_get_node(struct task_struct *tsk); 70 71 /* 72 * Simple work processor based on kthread. 73 * 74 * This provides easier way to make use of kthreads. A kthread_work 75 * can be queued and flushed using queue/kthread_flush_work() 76 * respectively. Queued kthread_works are processed by a kthread 77 * running kthread_worker_fn(). 78 */ 79 struct kthread_work; 80 typedef void (*kthread_work_func_t)(struct kthread_work *work); 81 void kthread_delayed_work_timer_fn(struct timer_list *t); 82 83 enum { 84 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 85 }; 86 87 struct kthread_worker { 88 unsigned int flags; 89 raw_spinlock_t lock; 90 struct list_head work_list; 91 struct list_head delayed_work_list; 92 struct task_struct *task; 93 struct kthread_work *current_work; 94 }; 95 96 struct kthread_work { 97 struct list_head node; 98 kthread_work_func_t func; 99 struct kthread_worker *worker; 100 /* Number of canceling calls that are running at the moment. */ 101 int canceling; 102 }; 103 104 struct kthread_delayed_work { 105 struct kthread_work work; 106 struct timer_list timer; 107 }; 108 109 #define KTHREAD_WORKER_INIT(worker) { \ 110 .lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock), \ 111 .work_list = LIST_HEAD_INIT((worker).work_list), \ 112 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ 113 } 114 115 #define KTHREAD_WORK_INIT(work, fn) { \ 116 .node = LIST_HEAD_INIT((work).node), \ 117 .func = (fn), \ 118 } 119 120 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 121 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 122 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\ 123 TIMER_IRQSAFE), \ 124 } 125 126 #define DEFINE_KTHREAD_WORKER(worker) \ 127 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 128 129 #define DEFINE_KTHREAD_WORK(work, fn) \ 130 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 131 132 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ 133 struct kthread_delayed_work dwork = \ 134 KTHREAD_DELAYED_WORK_INIT(dwork, fn) 135 136 /* 137 * kthread_worker.lock needs its own lockdep class key when defined on 138 * stack with lockdep enabled. Use the following macros in such cases. 139 */ 140 #ifdef CONFIG_LOCKDEP 141 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 142 ({ kthread_init_worker(&worker); worker; }) 143 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 144 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 145 #else 146 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 147 #endif 148 149 extern void __kthread_init_worker(struct kthread_worker *worker, 150 const char *name, struct lock_class_key *key); 151 152 #define kthread_init_worker(worker) \ 153 do { \ 154 static struct lock_class_key __key; \ 155 __kthread_init_worker((worker), "("#worker")->lock", &__key); \ 156 } while (0) 157 158 #define kthread_init_work(work, fn) \ 159 do { \ 160 memset((work), 0, sizeof(struct kthread_work)); \ 161 INIT_LIST_HEAD(&(work)->node); \ 162 (work)->func = (fn); \ 163 } while (0) 164 165 #define kthread_init_delayed_work(dwork, fn) \ 166 do { \ 167 kthread_init_work(&(dwork)->work, (fn)); \ 168 timer_setup(&(dwork)->timer, \ 169 kthread_delayed_work_timer_fn, 0); \ 170 } while (0) 171 172 int kthread_worker_fn(void *worker_ptr); 173 174 __printf(2, 3) 175 struct kthread_worker * 176 kthread_create_worker(unsigned int flags, const char namefmt[], ...); 177 178 __printf(3, 4) struct kthread_worker * 179 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 180 const char namefmt[], ...); 181 182 bool kthread_queue_work(struct kthread_worker *worker, 183 struct kthread_work *work); 184 185 bool kthread_queue_delayed_work(struct kthread_worker *worker, 186 struct kthread_delayed_work *dwork, 187 unsigned long delay); 188 189 bool kthread_mod_delayed_work(struct kthread_worker *worker, 190 struct kthread_delayed_work *dwork, 191 unsigned long delay); 192 193 void kthread_flush_work(struct kthread_work *work); 194 void kthread_flush_worker(struct kthread_worker *worker); 195 196 bool kthread_cancel_work_sync(struct kthread_work *work); 197 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 198 199 void kthread_destroy_worker(struct kthread_worker *worker); 200 201 #ifdef CONFIG_BLK_CGROUP 202 void kthread_associate_blkcg(struct cgroup_subsys_state *css); 203 struct cgroup_subsys_state *kthread_blkcg(void); 204 #else 205 static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { } 206 static inline struct cgroup_subsys_state *kthread_blkcg(void) 207 { 208 return NULL; 209 } 210 #endif 211 #endif /* _LINUX_KTHREAD_H */ 212