1 #ifndef _LINUX_KTHREAD_H 2 #define _LINUX_KTHREAD_H 3 /* Simple interface for creating and stopping kernel threads without mess. */ 4 #include <linux/err.h> 5 #include <linux/sched.h> 6 7 __printf(4, 5) 8 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), 9 void *data, 10 int node, 11 const char namefmt[], ...); 12 13 #define kthread_create(threadfn, data, namefmt, arg...) \ 14 kthread_create_on_node(threadfn, data, -1, namefmt, ##arg) 15 16 17 /** 18 * kthread_run - create and wake a thread. 19 * @threadfn: the function to run until signal_pending(current). 20 * @data: data ptr for @threadfn. 21 * @namefmt: printf-style name for the thread. 22 * 23 * Description: Convenient wrapper for kthread_create() followed by 24 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 25 */ 26 #define kthread_run(threadfn, data, namefmt, ...) \ 27 ({ \ 28 struct task_struct *__k \ 29 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 30 if (!IS_ERR(__k)) \ 31 wake_up_process(__k); \ 32 __k; \ 33 }) 34 35 void kthread_bind(struct task_struct *k, unsigned int cpu); 36 int kthread_stop(struct task_struct *k); 37 int kthread_should_stop(void); 38 bool kthread_freezable_should_stop(bool *was_frozen); 39 void *kthread_data(struct task_struct *k); 40 41 int kthreadd(void *unused); 42 extern struct task_struct *kthreadd_task; 43 extern int tsk_fork_get_node(struct task_struct *tsk); 44 45 /* 46 * Simple work processor based on kthread. 47 * 48 * This provides easier way to make use of kthreads. A kthread_work 49 * can be queued and flushed using queue/flush_kthread_work() 50 * respectively. Queued kthread_works are processed by a kthread 51 * running kthread_worker_fn(). 52 */ 53 struct kthread_work; 54 typedef void (*kthread_work_func_t)(struct kthread_work *work); 55 56 struct kthread_worker { 57 spinlock_t lock; 58 struct list_head work_list; 59 struct task_struct *task; 60 struct kthread_work *current_work; 61 }; 62 63 struct kthread_work { 64 struct list_head node; 65 kthread_work_func_t func; 66 wait_queue_head_t done; 67 struct kthread_worker *worker; 68 }; 69 70 #define KTHREAD_WORKER_INIT(worker) { \ 71 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ 72 .work_list = LIST_HEAD_INIT((worker).work_list), \ 73 } 74 75 #define KTHREAD_WORK_INIT(work, fn) { \ 76 .node = LIST_HEAD_INIT((work).node), \ 77 .func = (fn), \ 78 .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \ 79 } 80 81 #define DEFINE_KTHREAD_WORKER(worker) \ 82 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 83 84 #define DEFINE_KTHREAD_WORK(work, fn) \ 85 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 86 87 /* 88 * kthread_worker.lock and kthread_work.done need their own lockdep class 89 * keys if they are defined on stack with lockdep enabled. Use the 90 * following macros when defining them on stack. 91 */ 92 #ifdef CONFIG_LOCKDEP 93 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 94 ({ init_kthread_worker(&worker); worker; }) 95 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 96 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 97 # define KTHREAD_WORK_INIT_ONSTACK(work, fn) \ 98 ({ init_kthread_work((&work), fn); work; }) 99 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \ 100 struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn) 101 #else 102 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 103 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn) 104 #endif 105 106 extern void __init_kthread_worker(struct kthread_worker *worker, 107 const char *name, struct lock_class_key *key); 108 109 #define init_kthread_worker(worker) \ 110 do { \ 111 static struct lock_class_key __key; \ 112 __init_kthread_worker((worker), "("#worker")->lock", &__key); \ 113 } while (0) 114 115 #define init_kthread_work(work, fn) \ 116 do { \ 117 memset((work), 0, sizeof(struct kthread_work)); \ 118 INIT_LIST_HEAD(&(work)->node); \ 119 (work)->func = (fn); \ 120 init_waitqueue_head(&(work)->done); \ 121 } while (0) 122 123 int kthread_worker_fn(void *worker_ptr); 124 125 bool queue_kthread_work(struct kthread_worker *worker, 126 struct kthread_work *work); 127 void flush_kthread_work(struct kthread_work *work); 128 void flush_kthread_worker(struct kthread_worker *worker); 129 130 #endif /* _LINUX_KTHREAD_H */ 131