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 * A kthread_work can't be freed while it is executing. 54 */ 55 struct kthread_work; 56 typedef void (*kthread_work_func_t)(struct kthread_work *work); 57 58 struct kthread_worker { 59 spinlock_t lock; 60 struct list_head work_list; 61 struct task_struct *task; 62 }; 63 64 struct kthread_work { 65 struct list_head node; 66 kthread_work_func_t func; 67 wait_queue_head_t done; 68 atomic_t flushing; 69 int queue_seq; 70 int done_seq; 71 }; 72 73 #define KTHREAD_WORKER_INIT(worker) { \ 74 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ 75 .work_list = LIST_HEAD_INIT((worker).work_list), \ 76 } 77 78 #define KTHREAD_WORK_INIT(work, fn) { \ 79 .node = LIST_HEAD_INIT((work).node), \ 80 .func = (fn), \ 81 .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \ 82 .flushing = ATOMIC_INIT(0), \ 83 } 84 85 #define DEFINE_KTHREAD_WORKER(worker) \ 86 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 87 88 #define DEFINE_KTHREAD_WORK(work, fn) \ 89 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 90 91 /* 92 * kthread_worker.lock and kthread_work.done need their own lockdep class 93 * keys if they are defined on stack with lockdep enabled. Use the 94 * following macros when defining them on stack. 95 */ 96 #ifdef CONFIG_LOCKDEP 97 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 98 ({ init_kthread_worker(&worker); worker; }) 99 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 100 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 101 # define KTHREAD_WORK_INIT_ONSTACK(work, fn) \ 102 ({ init_kthread_work((&work), fn); work; }) 103 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \ 104 struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn) 105 #else 106 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 107 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn) 108 #endif 109 110 extern void __init_kthread_worker(struct kthread_worker *worker, 111 const char *name, struct lock_class_key *key); 112 113 #define init_kthread_worker(worker) \ 114 do { \ 115 static struct lock_class_key __key; \ 116 __init_kthread_worker((worker), "("#worker")->lock", &__key); \ 117 } while (0) 118 119 #define init_kthread_work(work, fn) \ 120 do { \ 121 memset((work), 0, sizeof(struct kthread_work)); \ 122 INIT_LIST_HEAD(&(work)->node); \ 123 (work)->func = (fn); \ 124 init_waitqueue_head(&(work)->done); \ 125 } while (0) 126 127 int kthread_worker_fn(void *worker_ptr); 128 129 bool queue_kthread_work(struct kthread_worker *worker, 130 struct kthread_work *work); 131 void flush_kthread_work(struct kthread_work *work); 132 void flush_kthread_worker(struct kthread_worker *worker); 133 134 #endif /* _LINUX_KTHREAD_H */ 135