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 __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 /**
  14  * kthread_create - create a kthread on the current node
  15  * @threadfn: the function to run in the thread
  16  * @data: data pointer for @threadfn()
  17  * @namefmt: printf-style format string for the thread name
  18  * @...: arguments for @namefmt.
  19  *
  20  * This macro will create a kthread on the current node, leaving it in
  21  * the stopped state.  This is just a helper for kthread_create_on_node();
  22  * see the documentation there for more details.
  23  */
  24 #define kthread_create(threadfn, data, namefmt, arg...) \
  25         kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)
  26
  27
  28 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
  29                                           void *data,
  30                                           unsigned int cpu,
  31                                           const char *namefmt);
  32
  33 /**
  34  * kthread_run - create and wake a thread.
  35  * @threadfn: the function to run until signal_pending(current).
  36  * @data: data ptr for @threadfn.
  37  * @namefmt: printf-style name for the thread.
  38  *
  39  * Description: Convenient wrapper for kthread_create() followed by
  40  * wake_up_process().  Returns the kthread or ERR_PTR(-ENOMEM).
  41  */
  42 #define kthread_run(threadfn, data, namefmt, ...)                          \
  43 ({                                                                         \
  44         struct task_struct *__k                                            \
  45                 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
  46         if (!IS_ERR(__k))                                                  \
  47                 wake_up_process(__k);                                      \
  48         __k;                                                               \
  49 })
  50
  51 void kthread_bind(struct task_struct *k, unsigned int cpu);
  52 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
  53 int kthread_stop(struct task_struct *k);
  54 bool kthread_should_stop(void);
  55 bool kthread_should_park(void);
  56 bool kthread_freezable_should_stop(bool *was_frozen);
  57 void *kthread_data(struct task_struct *k);
  58 void *kthread_probe_data(struct task_struct *k);
  59 int kthread_park(struct task_struct *k);
  60 void kthread_unpark(struct task_struct *k);
  61 void kthread_parkme(void);
  62
  63 int kthreadd(void *unused);
  64 extern struct task_struct *kthreadd_task;
  65 extern int tsk_fork_get_node(struct task_struct *tsk);
  66
  67 /*
  68  * Simple work processor based on kthread.
  69  *
  70  * This provides easier way to make use of kthreads.  A kthread_work
  71  * can be queued and flushed using queue/kthread_flush_work()
  72  * respectively.  Queued kthread_works are processed by a kthread
  73  * running kthread_worker_fn().
  74  */
  75 struct kthread_work;
  76 typedef void (*kthread_work_func_t)(struct kthread_work *work);
  77 void kthread_delayed_work_timer_fn(unsigned long __data);
  78
  79 enum {
  80         KTW_FREEZABLE           = 1 << 0,       /* freeze during suspend */
  81 };
  82
  83 struct kthread_worker {
  84         unsigned int            flags;
  85         spinlock_t              lock;
  86         struct list_head        work_list;
  87         struct list_head        delayed_work_list;
  88         struct task_struct      *task;
  89         struct kthread_work     *current_work;
  90 };
  91
  92 struct kthread_work {
  93         struct list_head        node;
  94         kthread_work_func_t     func;
  95         struct kthread_worker   *worker;
  96         /* Number of canceling calls that are running at the moment. */
  97         int                     canceling;
  98 };
  99
 100 struct kthread_delayed_work {
 101         struct kthread_work work;
 102         struct timer_list timer;
 103 };
 104
 105 #define KTHREAD_WORKER_INIT(worker)     {                               \
 106         .lock = __SPIN_LOCK_UNLOCKED((worker).lock),                    \
 107         .work_list = LIST_HEAD_INIT((worker).work_list),                \
 108         .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
 109         }
 110
 111 #define KTHREAD_WORK_INIT(work, fn)     {                               \
 112         .node = LIST_HEAD_INIT((work).node),                            \
 113         .func = (fn),                                                   \
 114         }
 115
 116 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {                          \
 117         .work = KTHREAD_WORK_INIT((dwork).work, (fn)),                  \
 118         .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,     \
 119                                      0, (unsigned long)&(dwork),        \
 120                                      TIMER_IRQSAFE),                    \
 121         }
 122
 123 #define DEFINE_KTHREAD_WORKER(worker)                                   \
 124         struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
 125
 126 #define DEFINE_KTHREAD_WORK(work, fn)                                   \
 127         struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
 128
 129 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)                          \
 130         struct kthread_delayed_work dwork =                             \
 131                 KTHREAD_DELAYED_WORK_INIT(dwork, fn)
 132
 133 /*
 134  * kthread_worker.lock needs its own lockdep class key when defined on
 135  * stack with lockdep enabled.  Use the following macros in such cases.
 136  */
 137 #ifdef CONFIG_LOCKDEP
 138 # define KTHREAD_WORKER_INIT_ONSTACK(worker)                            \
 139         ({ kthread_init_worker(&worker); worker; })
 140 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker)                          \
 141         struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
 142 #else
 143 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
 144 #endif
 145
 146 extern void __kthread_init_worker(struct kthread_worker *worker,
 147                         const char *name, struct lock_class_key *key);
 148
 149 #define kthread_init_worker(worker)                                     \
 150         do {                                                            \
 151                 static struct lock_class_key __key;                     \
 152                 __kthread_init_worker((worker), "("#worker")->lock", &__key); \
 153         } while (0)
 154
 155 #define kthread_init_work(work, fn)                                     \
 156         do {                                                            \
 157                 memset((work), 0, sizeof(struct kthread_work));         \
 158                 INIT_LIST_HEAD(&(work)->node);                          \
 159                 (work)->func = (fn);                                    \
 160         } while (0)
 161
 162 #define kthread_init_delayed_work(dwork, fn)                            \
 163         do {                                                            \
 164                 kthread_init_work(&(dwork)->work, (fn));                \
 165                 __setup_timer(&(dwork)->timer,                          \
 166                               kthread_delayed_work_timer_fn,            \
 167                               (unsigned long)(dwork),                   \
 168                               TIMER_IRQSAFE);                           \
 169         } while (0)
 170
 171 int kthread_worker_fn(void *worker_ptr);
 172
 173 __printf(2, 3)
 174 struct kthread_worker *
 175 kthread_create_worker(unsigned int flags, const char namefmt[], ...);
 176
 177 struct kthread_worker *
 178 kthread_create_worker_on_cpu(int cpu, unsigned int flags,
 179                              const char namefmt[], ...);
 180
 181 bool kthread_queue_work(struct kthread_worker *worker,
 182                         struct kthread_work *work);
 183
 184 bool kthread_queue_delayed_work(struct kthread_worker *worker,
 185                                 struct kthread_delayed_work *dwork,
 186                                 unsigned long delay);
 187
 188 bool kthread_mod_delayed_work(struct kthread_worker *worker,
 189                               struct kthread_delayed_work *dwork,
 190                               unsigned long delay);
 191
 192 void kthread_flush_work(struct kthread_work *work);
 193 void kthread_flush_worker(struct kthread_worker *worker);
 194
 195 bool kthread_cancel_work_sync(struct kthread_work *work);
 196 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
 197
 198 void kthread_destroy_worker(struct kthread_worker *worker);
 199
 200 #endif /* _LINUX_KTHREAD_H */