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 free_kthread_struct(struct task_struct *k);
  52 void kthread_bind(struct task_struct *k, unsigned int cpu);
  53 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
  54 int kthread_stop(struct task_struct *k);
  55 bool kthread_should_stop(void);
  56 bool kthread_should_park(void);
  57 bool kthread_freezable_should_stop(bool *was_frozen);
  58 void *kthread_data(struct task_struct *k);
  59 void *kthread_probe_data(struct task_struct *k);
  60 int kthread_park(struct task_struct *k);
  61 void kthread_unpark(struct task_struct *k);
  62 void kthread_parkme(void);
  63
  64 int kthreadd(void *unused);
  65 extern struct task_struct *kthreadd_task;
  66 extern int tsk_fork_get_node(struct task_struct *tsk);
  67
  68 /*
  69  * Simple work processor based on kthread.
  70  *
  71  * This provides easier way to make use of kthreads.  A kthread_work
  72  * can be queued and flushed using queue/kthread_flush_work()
  73  * respectively.  Queued kthread_works are processed by a kthread
  74  * running kthread_worker_fn().
  75  */
  76 struct kthread_work;
  77 typedef void (*kthread_work_func_t)(struct kthread_work *work);
  78 void kthread_delayed_work_timer_fn(unsigned long __data);
  79
  80 enum {
  81         KTW_FREEZABLE           = 1 << 0,       /* freeze during suspend */
  82 };
  83
  84 struct kthread_worker {
  85         unsigned int            flags;
  86         spinlock_t              lock;
  87         struct list_head        work_list;
  88         struct list_head        delayed_work_list;
  89         struct task_struct      *task;
  90         struct kthread_work     *current_work;
  91 };
  92
  93 struct kthread_work {
  94         struct list_head        node;
  95         kthread_work_func_t     func;
  96         struct kthread_worker   *worker;
  97         /* Number of canceling calls that are running at the moment. */
  98         int                     canceling;
  99 };
 100
 101 struct kthread_delayed_work {
 102         struct kthread_work work;
 103         struct timer_list timer;
 104 };
 105
 106 #define KTHREAD_WORKER_INIT(worker)     {                               \
 107         .lock = __SPIN_LOCK_UNLOCKED((worker).lock),                    \
 108         .work_list = LIST_HEAD_INIT((worker).work_list),                \
 109         .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\
 110         }
 111
 112 #define KTHREAD_WORK_INIT(work, fn)     {                               \
 113         .node = LIST_HEAD_INIT((work).node),                            \
 114         .func = (fn),                                                   \
 115         }
 116
 117 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {                          \
 118         .work = KTHREAD_WORK_INIT((dwork).work, (fn)),                  \
 119         .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,     \
 120                                      0, (unsigned long)&(dwork),        \
 121                                      TIMER_IRQSAFE),                    \
 122         }
 123
 124 #define DEFINE_KTHREAD_WORKER(worker)                                   \
 125         struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
 126
 127 #define DEFINE_KTHREAD_WORK(work, fn)                                   \
 128         struct kthread_work work = KTHREAD_WORK_INIT(work, fn)
 129
 130 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)                          \
 131         struct kthread_delayed_work dwork =                             \
 132                 KTHREAD_DELAYED_WORK_INIT(dwork, fn)
 133
 134 /*
 135  * kthread_worker.lock needs its own lockdep class key when defined on
 136  * stack with lockdep enabled.  Use the following macros in such cases.
 137  */
 138 #ifdef CONFIG_LOCKDEP
 139 # define KTHREAD_WORKER_INIT_ONSTACK(worker)                            \
 140         ({ kthread_init_worker(&worker); worker; })
 141 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker)                          \
 142         struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)
 143 #else
 144 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)
 145 #endif
 146
 147 extern void __kthread_init_worker(struct kthread_worker *worker,
 148                         const char *name, struct lock_class_key *key);
 149
 150 #define kthread_init_worker(worker)                                     \
 151         do {                                                            \
 152                 static struct lock_class_key __key;                     \
 153                 __kthread_init_worker((worker), "("#worker")->lock", &__key); \
 154         } while (0)
 155
 156 #define kthread_init_work(work, fn)                                     \
 157         do {                                                            \
 158                 memset((work), 0, sizeof(struct kthread_work));         \
 159                 INIT_LIST_HEAD(&(work)->node);                          \
 160                 (work)->func = (fn);                                    \
 161         } while (0)
 162
 163 #define kthread_init_delayed_work(dwork, fn)                            \
 164         do {                                                            \
 165                 kthread_init_work(&(dwork)->work, (fn));                \
 166                 __setup_timer(&(dwork)->timer,                          \
 167                               kthread_delayed_work_timer_fn,            \
 168                               (unsigned long)(dwork),                   \
 169                               TIMER_IRQSAFE);                           \
 170         } while (0)
 171
 172 int kthread_worker_fn(void *worker_ptr);
 173
 174 __printf(2, 3)
 175 struct kthread_worker *
 176 kthread_create_worker(unsigned int flags, const char namefmt[], ...);
 177
 178 __printf(3, 4) struct kthread_worker *
 179 kthread_create_worker_on_cpu(int cpu, unsigned int flags,
 180                              const char namefmt[], ...);
 181
 182 bool kthread_queue_work(struct kthread_worker *worker,
 183                         struct kthread_work *work);
 184
 185 bool kthread_queue_delayed_work(struct kthread_worker *worker,
 186                                 struct kthread_delayed_work *dwork,
 187                                 unsigned long delay);
 188
 189 bool kthread_mod_delayed_work(struct kthread_worker *worker,
 190                               struct kthread_delayed_work *dwork,
 191                               unsigned long delay);
 192
 193 void kthread_flush_work(struct kthread_work *work);
 194 void kthread_flush_worker(struct kthread_worker *worker);
 195
 196 bool kthread_cancel_work_sync(struct kthread_work *work);
 197 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
 198
 199 void kthread_destroy_worker(struct kthread_worker *worker);
 200
 201 #endif /* _LINUX_KTHREAD_H */