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 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), 8 void *data, 9 int node, 10 const char namefmt[], ...) 11 __attribute__((format(printf, 4, 5))); 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 void *kthread_data(struct task_struct *k); 39 40 int kthreadd(void *unused); 41 extern struct task_struct *kthreadd_task; 42 extern int tsk_fork_get_node(struct task_struct *tsk); 43 44 /* 45 * Simple work processor based on kthread. 46 * 47 * This provides easier way to make use of kthreads. A kthread_work 48 * can be queued and flushed using queue/flush_kthread_work() 49 * respectively. Queued kthread_works are processed by a kthread 50 * running kthread_worker_fn(). 51 * 52 * A kthread_work can't be freed while it is executing. 53 */ 54 struct kthread_work; 55 typedef void (*kthread_work_func_t)(struct kthread_work *work); 56 57 struct kthread_worker { 58 spinlock_t lock; 59 struct list_head work_list; 60 struct task_struct *task; 61 }; 62 63 struct kthread_work { 64 struct list_head node; 65 kthread_work_func_t func; 66 wait_queue_head_t done; 67 atomic_t flushing; 68 int queue_seq; 69 int done_seq; 70 }; 71 72 #define KTHREAD_WORKER_INIT(worker) { \ 73 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ 74 .work_list = LIST_HEAD_INIT((worker).work_list), \ 75 } 76 77 #define KTHREAD_WORK_INIT(work, fn) { \ 78 .node = LIST_HEAD_INIT((work).node), \ 79 .func = (fn), \ 80 .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \ 81 .flushing = ATOMIC_INIT(0), \ 82 } 83 84 #define DEFINE_KTHREAD_WORKER(worker) \ 85 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 86 87 #define DEFINE_KTHREAD_WORK(work, fn) \ 88 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 89 90 /* 91 * kthread_worker.lock and kthread_work.done need their own lockdep class 92 * keys if they are defined on stack with lockdep enabled. Use the 93 * following macros when defining them on stack. 94 */ 95 #ifdef CONFIG_LOCKDEP 96 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 97 ({ init_kthread_worker(&worker); worker; }) 98 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 99 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 100 # define KTHREAD_WORK_INIT_ONSTACK(work, fn) \ 101 ({ init_kthread_work((&work), fn); work; }) 102 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \ 103 struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn) 104 #else 105 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 106 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn) 107 #endif 108 109 extern void __init_kthread_worker(struct kthread_worker *worker, 110 const char *name, struct lock_class_key *key); 111 112 #define init_kthread_worker(worker) \ 113 do { \ 114 static struct lock_class_key __key; \ 115 __init_kthread_worker((worker), "("#worker")->lock", &__key); \ 116 } while (0) 117 118 #define init_kthread_work(work, fn) \ 119 do { \ 120 memset((work), 0, sizeof(struct kthread_work)); \ 121 INIT_LIST_HEAD(&(work)->node); \ 122 (work)->func = (fn); \ 123 init_waitqueue_head(&(work)->done); \ 124 } while (0) 125 126 int kthread_worker_fn(void *worker_ptr); 127 128 bool queue_kthread_work(struct kthread_worker *worker, 129 struct kthread_work *work); 130 void flush_kthread_work(struct kthread_work *work); 131 void flush_kthread_worker(struct kthread_worker *worker); 132 133 #endif /* _LINUX_KTHREAD_H */ 134