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(int (*threadfn)(void *data), 8 void *data, 9 const char namefmt[], ...) 10 __attribute__((format(printf, 3, 4))); 11 12 /** 13 * kthread_run - create and wake a thread. 14 * @threadfn: the function to run until signal_pending(current). 15 * @data: data ptr for @threadfn. 16 * @namefmt: printf-style name for the thread. 17 * 18 * Description: Convenient wrapper for kthread_create() followed by 19 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 20 */ 21 #define kthread_run(threadfn, data, namefmt, ...) \ 22 ({ \ 23 struct task_struct *__k \ 24 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 25 if (!IS_ERR(__k)) \ 26 wake_up_process(__k); \ 27 __k; \ 28 }) 29 30 void kthread_bind(struct task_struct *k, unsigned int cpu); 31 int kthread_stop(struct task_struct *k); 32 int kthread_should_stop(void); 33 void *kthread_data(struct task_struct *k); 34 35 int kthreadd(void *unused); 36 extern struct task_struct *kthreadd_task; 37 38 /* 39 * Simple work processor based on kthread. 40 * 41 * This provides easier way to make use of kthreads. A kthread_work 42 * can be queued and flushed using queue/flush_kthread_work() 43 * respectively. Queued kthread_works are processed by a kthread 44 * running kthread_worker_fn(). 45 * 46 * A kthread_work can't be freed while it is executing. 47 */ 48 struct kthread_work; 49 typedef void (*kthread_work_func_t)(struct kthread_work *work); 50 51 struct kthread_worker { 52 spinlock_t lock; 53 struct list_head work_list; 54 struct task_struct *task; 55 }; 56 57 struct kthread_work { 58 struct list_head node; 59 kthread_work_func_t func; 60 wait_queue_head_t done; 61 atomic_t flushing; 62 int queue_seq; 63 int done_seq; 64 }; 65 66 #define KTHREAD_WORKER_INIT(worker) { \ 67 .lock = SPIN_LOCK_UNLOCKED, \ 68 .work_list = LIST_HEAD_INIT((worker).work_list), \ 69 } 70 71 #define KTHREAD_WORK_INIT(work, fn) { \ 72 .node = LIST_HEAD_INIT((work).node), \ 73 .func = (fn), \ 74 .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done), \ 75 .flushing = ATOMIC_INIT(0), \ 76 } 77 78 #define DEFINE_KTHREAD_WORKER(worker) \ 79 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 80 81 #define DEFINE_KTHREAD_WORK(work, fn) \ 82 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 83 84 /* 85 * kthread_worker.lock and kthread_work.done need their own lockdep class 86 * keys if they are defined on stack with lockdep enabled. Use the 87 * following macros when defining them on stack. 88 */ 89 #ifdef CONFIG_LOCKDEP 90 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 91 ({ init_kthread_worker(&worker); worker; }) 92 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 93 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 94 # define KTHREAD_WORK_INIT_ONSTACK(work, fn) \ 95 ({ init_kthread_work((&work), fn); work; }) 96 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) \ 97 struct kthread_work work = KTHREAD_WORK_INIT_ONSTACK(work, fn) 98 #else 99 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 100 # define DEFINE_KTHREAD_WORK_ONSTACK(work, fn) DEFINE_KTHREAD_WORK(work, fn) 101 #endif 102 103 extern void __init_kthread_worker(struct kthread_worker *worker, 104 const char *name, struct lock_class_key *key); 105 106 #define init_kthread_worker(worker) \ 107 do { \ 108 static struct lock_class_key __key; \ 109 __init_kthread_worker((worker), "("#worker")->lock", &__key); \ 110 } while (0) 111 112 #define init_kthread_work(work, fn) \ 113 do { \ 114 memset((work), 0, sizeof(struct kthread_work)); \ 115 INIT_LIST_HEAD(&(work)->node); \ 116 (work)->func = (fn); \ 117 init_waitqueue_head(&(work)->done); \ 118 } while (0) 119 120 int kthread_worker_fn(void *worker_ptr); 121 122 bool queue_kthread_work(struct kthread_worker *worker, 123 struct kthread_work *work); 124 void flush_kthread_work(struct kthread_work *work); 125 void flush_kthread_worker(struct kthread_worker *worker); 126 127 #endif /* _LINUX_KTHREAD_H */ 128