include/linux/kthread.h

   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
  34 int kthreadd(void *unused);
  35 extern struct task_struct *kthreadd_task;
  36
  37 /*
  38  * Simple work processor based on kthread.
  39  *
  40  * This provides easier way to make use of kthreads.  A kthread_work
  41  * can be queued and flushed using queue/flush_kthread_work()
  42  * respectively.  Queued kthread_works are processed by a kthread
  43  * running kthread_worker_fn().
  44  *
  45  * A kthread_work can't be freed while it is executing.
  46  */
  47 struct kthread_work;
  48 typedef void (*kthread_work_func_t)(struct kthread_work *work);
  49
  50 struct kthread_worker {
  51         spinlock_t              lock;
  52         struct list_head        work_list;
  53         struct task_struct      *task;
  54 };
  55
  56 struct kthread_work {
  57         struct list_head        node;
  58         kthread_work_func_t     func;
  59         wait_queue_head_t       done;
  60         atomic_t                flushing;
  61         int                     queue_seq;
  62         int                     done_seq;
  63 };
  64
  65 #define KTHREAD_WORKER_INIT(worker)     {                               \
  66         .lock = SPIN_LOCK_UNLOCKED,                                     \
  67         .work_list = LIST_HEAD_INIT((worker).work_list),                \
  68         }
  69
  70 #define KTHREAD_WORK_INIT(work, fn)     {                               \
  71         .node = LIST_HEAD_INIT((work).node),                            \
  72         .func = (fn),                                                   \
  73         .done = __WAIT_QUEUE_HEAD_INITIALIZER((work).done),             \
  74         .flushing = ATOMIC_INIT(0),                                     \
  75         }
  76
  77 #define DEFINE_KTHREAD_WORKER(worker)                                   \
  78         struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
  79
  80 #define DEFINE_KTHREAD_WORK(work, fn)                                   \
  81         struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
  82
  83 static inline void init_kthread_worker(struct kthread_worker *worker)
  84 {
  85         *worker = (struct kthread_worker)KTHREAD_WORKER_INIT(*worker);
  86 }
  87
  88 static inline void init_kthread_work(struct kthread_work *work,
  89                                      kthread_work_func_t fn)
  90 {
  91         *work = (struct kthread_work)KTHREAD_WORK_INIT(*work, fn);
  92 }
  93
  94 int kthread_worker_fn(void *worker_ptr);
  95
  96 bool queue_kthread_work(struct kthread_worker *worker,
  97                         struct kthread_work *work);
  98 void flush_kthread_work(struct kthread_work *work);
  99 void flush_kthread_worker(struct kthread_worker *worker);
 100
 101 #endif /* _LINUX_KTHREAD_H */