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 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), 18 void *data, 19 unsigned int cpu, 20 const char *namefmt); 21 22 /** 23 * kthread_run - create and wake a thread. 24 * @threadfn: the function to run until signal_pending(current). 25 * @data: data ptr for @threadfn. 26 * @namefmt: printf-style name for the thread. 27 * 28 * Description: Convenient wrapper for kthread_create() followed by 29 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 30 */ 31 #define kthread_run(threadfn, data, namefmt, ...) \ 32 ({ \ 33 struct task_struct *__k \ 34 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 35 if (!IS_ERR(__k)) \ 36 wake_up_process(__k); \ 37 __k; \ 38 }) 39 40 void kthread_bind(struct task_struct *k, unsigned int cpu); 41 int kthread_stop(struct task_struct *k); 42 bool kthread_should_stop(void); 43 bool kthread_should_park(void); 44 bool kthread_freezable_should_stop(bool *was_frozen); 45 void *kthread_data(struct task_struct *k); 46 int kthread_park(struct task_struct *k); 47 void kthread_unpark(struct task_struct *k); 48 void kthread_parkme(void); 49 50 int kthreadd(void *unused); 51 extern struct task_struct *kthreadd_task; 52 extern int tsk_fork_get_node(struct task_struct *tsk); 53 54 /* 55 * Simple work processor based on kthread. 56 * 57 * This provides easier way to make use of kthreads. A kthread_work 58 * can be queued and flushed using queue/flush_kthread_work() 59 * respectively. Queued kthread_works are processed by a kthread 60 * running kthread_worker_fn(). 61 */ 62 struct kthread_work; 63 typedef void (*kthread_work_func_t)(struct kthread_work *work); 64 65 struct kthread_worker { 66 spinlock_t lock; 67 struct list_head work_list; 68 struct task_struct *task; 69 struct kthread_work *current_work; 70 }; 71 72 struct kthread_work { 73 struct list_head node; 74 kthread_work_func_t func; 75 wait_queue_head_t done; 76 struct kthread_worker *worker; 77 }; 78 79 #define KTHREAD_WORKER_INIT(worker) { \ 80 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ 81 .work_list = LIST_HEAD_INIT((worker).work_list), \ 82 } 83 84 #define KTHREAD_WORK_INIT(work, fn) { \ 85 .node = LIST_HEAD_INIT((work).node), \ 86 .func = (fn), \ 87 .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \ 88 } 89 90 #define DEFINE_KTHREAD_WORKER(worker) \ 91 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 92 93 #define DEFINE_KTHREAD_WORK(work, fn) \ 94 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 95 96 /* 97 * kthread_worker.lock and kthread_work.done need their own lockdep class 98 * keys if they are defined on stack with lockdep enabled. Use the 99 * following macros when defining them on stack. 100 */ 101 #ifdef CONFIG_LOCKDEP 102 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 103 ({ init_kthread_worker(&worker); worker; }) 104 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 105 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 106 # define KTHREAD_WORK_INIT_ONSTACK(work, fn) \ 107 ({ init_kthread_work((&work), fn); work; }) 108 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \ 109 struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn) 110 #else 111 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 112 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn) 113 #endif 114 115 extern void __init_kthread_worker(struct kthread_worker *worker, 116 const char *name, struct lock_class_key *key); 117 118 #define init_kthread_worker(worker) \ 119 do { \ 120 static struct lock_class_key __key; \ 121 __init_kthread_worker((worker), "("#worker")->lock", &__key); \ 122 } while (0) 123 124 #define init_kthread_work(work, fn) \ 125 do { \ 126 memset((work), 0, sizeof(struct kthread_work)); \ 127 INIT_LIST_HEAD(&(work)->node); \ 128 (work)->func = (fn); \ 129 init_waitqueue_head(&(work)->done); \ 130 } while (0) 131 132 int kthread_worker_fn(void *worker_ptr); 133 134 bool queue_kthread_work(struct kthread_worker *worker, 135 struct kthread_work *work); 136 void flush_kthread_work(struct kthread_work *work); 137 void flush_kthread_worker(struct kthread_worker *worker); 138 139 #endif /* _LINUX_KTHREAD_H */ 140