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 #define kthread_create(threadfn, data, namefmt, arg...) \
  14         kthread_create_on_node(threadfn, data, NUMA_NO_NODE, 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 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
  42 int kthread_stop(struct task_struct *k);
  43 bool kthread_should_stop(void);
  44 bool kthread_should_park(void);
  45 bool kthread_freezable_should_stop(bool *was_frozen);
  46 void *kthread_data(struct task_struct *k);
  47 void *kthread_probe_data(struct task_struct *k);
  48 int kthread_park(struct task_struct *k);
  49 void kthread_unpark(struct task_struct *k);
  50 void kthread_parkme(void);
  51
  52 int kthreadd(void *unused);
  53 extern struct task_struct *kthreadd_task;
  54 extern int tsk_fork_get_node(struct task_struct *tsk);
  55
  56 /*
  57  * Simple work processor based on kthread.
  58  *
  59  * This provides easier way to make use of kthreads.  A kthread_work
  60  * can be queued and flushed using queue/kthread_flush_work()
  61  * respectively.  Queued kthread_works are processed by a kthread
  62  * running kthread_worker_fn().
  63  */
  64 struct kthread_work;
  65 typedef void (*kthread_work_func_t)(struct kthread_work *work);
  66 void kthread_delayed_work_timer_fn(unsigned long __data);
  67
  68 enum {
  69         KTW_FREEZABLE           = 1 << 0,       /* freeze during suspend */
  70 };
  71
  72 struct kthread_worker {
  73         unsigned int            flags;
  74         spinlock_t              lock;
  75         struct list_head        work_list;
  76         struct list_head        delayed_work_list;
  77         struct task_struct      *task;
  78         struct kthread_work     *current_work;
  79 };
  80
  81 struct kthread_work {
  82         struct list_head        node;
  83         kthread_work_func_t     func;
  84         struct kthread_worker   *worker;
  85         /* Number of canceling calls that are running at the moment. */
  86         int                     canceling;
  87 };
  88
  89 struct kthread_delayed_work {
  90         struct kthread_work work;
  91         struct timer_list timer;
  92 };
  93
  94 #define KTHREAD_WORKER_INIT(worker)     {                               \
  95         .lock = __SPIN_LOCK_UNLOCKED((worker).lock),                    \
  96         .work_list = LIST_HEAD_INIT((worker).work_list),                \
  97         .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
  98         }
  99
 100 #define KTHREAD_WORK_INIT(work, fn)     {                               \
 101         .node = LIST_HEAD_INIT((work).node),                            \
 102         .func = (fn),                                                   \
 103         }
 104
 105 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {                          \
 106         .work = KTHREAD_WORK_INIT((dwork).work, (fn)),                  \
 107         .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,     \
 108                                      0, (unsigned long)&(dwork),        \
 109                                      TIMER_IRQSAFE),                    \
 110         }
 111
 112 #define DEFINE_KTHREAD_WORKER(worker)                                   \
 113         struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
 114
 115 #define DEFINE_KTHREAD_WORK(work, fn)                                   \
 116         struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
 117
 118 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)                          \
 119         struct kthread_delayed_work dwork =                             \
 120                 KTHREAD_DELAYED_WORK_INIT(dwork, fn)
 121
 122 /*
 123  * kthread_worker.lock needs its own lockdep class key when defined on
 124  * stack with lockdep enabled.  Use the following macros in such cases.
 125  */
 126 #ifdef CONFIG_LOCKDEP
 127 # define KTHREAD_WORKER_INIT_ONSTACK(worker)                            \
 128         ({ kthread_init_worker(&worker); worker; })
 129 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker)                          \
 130         struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
 131 #else
 132 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
 133 #endif
 134
 135 extern void __kthread_init_worker(struct kthread_worker *worker,
 136                         const char *name, struct lock_class_key *key);
 137
 138 #define kthread_init_worker(worker)                                     \
 139         do {                                                            \
 140                 static struct lock_class_key __key;                     \
 141                 __kthread_init_worker((worker), "("#worker")->lock", &__key); \
 142         } while (0)
 143
 144 #define kthread_init_work(work, fn)                                     \
 145         do {                                                            \
 146                 memset((work), 0, sizeof(struct kthread_work));         \
 147                 INIT_LIST_HEAD(&(work)->node);                          \
 148                 (work)->func = (fn);                                    \
 149         } while (0)
 150
 151 #define kthread_init_delayed_work(dwork, fn)                            \
 152         do {                                                            \
 153                 kthread_init_work(&(dwork)->work, (fn));                \
 154                 __setup_timer(&(dwork)->timer,                          \
 155                               kthread_delayed_work_timer_fn,            \
 156                               (unsigned long)(dwork),                   \
 157                               TIMER_IRQSAFE);                           \
 158         } while (0)
 159
 160 int kthread_worker_fn(void *worker_ptr);
 161
 162 __printf(2, 3)
 163 struct kthread_worker *
 164 kthread_create_worker(unsigned int flags, const char namefmt[], ...);
 165
 166 struct kthread_worker *
 167 kthread_create_worker_on_cpu(int cpu, unsigned int flags,
 168                              const char namefmt[], ...);
 169
 170 bool kthread_queue_work(struct kthread_worker *worker,
 171                         struct kthread_work *work);
 172
 173 bool kthread_queue_delayed_work(struct kthread_worker *worker,
 174                                 struct kthread_delayed_work *dwork,
 175                                 unsigned long delay);
 176
 177 bool kthread_mod_delayed_work(struct kthread_worker *worker,
 178                               struct kthread_delayed_work *dwork,
 179                               unsigned long delay);
 180
 181 void kthread_flush_work(struct kthread_work *work);
 182 void kthread_flush_worker(struct kthread_worker *worker);
 183
 184 bool kthread_cancel_work_sync(struct kthread_work *work);
 185 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
 186
 187 void kthread_destroy_worker(struct kthread_worker *worker);
 188
 189 #endif /* _LINUX_KTHREAD_H */