/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef _LINUX_KTHREAD_H
  #define _LINUX_KTHREAD_H
  /* Simple interface for creating and stopping kernel threads without mess. */
  #include <linux/err.h>
  #include <linux/sched.h>

  struct mm_struct;

  __printf(4, 5)

  struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
  					   void *data,
  					   int node,

  					   const char namefmt[], ...);

  /**
   * kthread_create - create a kthread on the current node
   * @threadfn: the function to run in the thread
   * @data: data pointer for @threadfn()
   * @namefmt: printf-style format string for the thread name

   * @arg...: arguments for @namefmt.

   *
   * This macro will create a kthread on the current node, leaving it in
   * the stopped state.  This is just a helper for kthread_create_on_node();
   * see the documentation there for more details.
   */

  #define kthread_create(threadfn, data, namefmt, arg...) \

  	kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg)

  struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data),
  					  void *data,
  					  unsigned int cpu,
  					  const char *namefmt);

  /**

   * kthread_run - create and wake a thread.

   * @threadfn: the function to run until signal_pending(current).
   * @data: data ptr for @threadfn.
   * @namefmt: printf-style name for the thread.
   *
   * Description: Convenient wrapper for kthread_create() followed by

   * wake_up_process().  Returns the kthread or ERR_PTR(-ENOMEM).
   */

  #define kthread_run(threadfn, data, namefmt, ...)			   \
  ({									   \
  	struct task_struct *__k						   \
  		= kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \
  	if (!IS_ERR(__k))						   \
  		wake_up_process(__k);					   \
  	__k;								   \
  })

  void free_kthread_struct(struct task_struct *k);

  void kthread_bind(struct task_struct *k, unsigned int cpu);

  void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);

  int kthread_stop(struct task_struct *k);

  bool kthread_should_stop(void);
  bool kthread_should_park(void);

  bool __kthread_should_park(struct task_struct *k);

  bool kthread_freezable_should_stop(bool *was_frozen);

  void *kthread_func(struct task_struct *k);

  void *kthread_data(struct task_struct *k);

  void *kthread_probe_data(struct task_struct *k);

  int kthread_park(struct task_struct *k);
  void kthread_unpark(struct task_struct *k);
  void kthread_parkme(void);

  int kthreadd(void *unused);
  extern struct task_struct *kthreadd_task;

  extern int tsk_fork_get_node(struct task_struct *tsk);

  /*
   * Simple work processor based on kthread.
   *
   * This provides easier way to make use of kthreads.  A kthread_work

   * can be queued and flushed using queue/kthread_flush_work()

   * respectively.  Queued kthread_works are processed by a kthread
   * running kthread_worker_fn().

   */
  struct kthread_work;
  typedef void (*kthread_work_func_t)(struct kthread_work *work);

  void kthread_delayed_work_timer_fn(struct timer_list *t);

  enum {
  	KTW_FREEZABLE		= 1 << 0,	/* freeze during suspend */
  };

  struct kthread_worker {

  	unsigned int		flags;

  	raw_spinlock_t		lock;

  	struct list_head	work_list;

  	struct list_head	delayed_work_list;

  	struct task_struct	*task;

  	struct kthread_work	*current_work;

  };
  
  struct kthread_work {
  	struct list_head	node;
  	kthread_work_func_t	func;

  	struct kthread_worker	*worker;

  	/* Number of canceling calls that are running at the moment. */
  	int			canceling;

  };

  struct kthread_delayed_work {
  	struct kthread_work work;
  	struct timer_list timer;
  };

  #define KTHREAD_WORKER_INIT(worker)	{				\

  	.lock = __RAW_SPIN_LOCK_UNLOCKED((worker).lock),		\

  	.work_list = LIST_HEAD_INIT((worker).work_list),		\

  	.delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\

  	}
  
  #define KTHREAD_WORK_INIT(work, fn)	{				\
  	.node = LIST_HEAD_INIT((work).node),				\
  	.func = (fn),							\

  	}

  #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) {				\
  	.work = KTHREAD_WORK_INIT((dwork).work, (fn)),			\

  	.timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn,\

  				     TIMER_IRQSAFE),			\
  	}

  #define DEFINE_KTHREAD_WORKER(worker)					\
  	struct kthread_worker worker = KTHREAD_WORKER_INIT(worker)
  
  #define DEFINE_KTHREAD_WORK(work, fn)					\
  	struct kthread_work work = KTHREAD_WORK_INIT(work, fn)

  #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn)				\
  	struct kthread_delayed_work dwork =				\
  		KTHREAD_DELAYED_WORK_INIT(dwork, fn)

  /*

   * kthread_worker.lock needs its own lockdep class key when defined on
   * stack with lockdep enabled.  Use the following macros in such cases.

   */
  #ifdef CONFIG_LOCKDEP
  # define KTHREAD_WORKER_INIT_ONSTACK(worker)				\

  	({ kthread_init_worker(&worker); worker; })

  # define DEFINE_KTHREAD_WORKER_ONSTACK(worker)				\
  	struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker)

  #else
  # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker)

  #endif

  extern void __kthread_init_worker(struct kthread_worker *worker,

  			const char *name, struct lock_class_key *key);

  #define kthread_init_worker(worker)					\

  	do {								\
  		static struct lock_class_key __key;			\

  		__kthread_init_worker((worker), "("#worker")->lock", &__key); \

  	} while (0)

  #define kthread_init_work(work, fn)					\

  	do {								\
  		memset((work), 0, sizeof(struct kthread_work));		\
  		INIT_LIST_HEAD(&(work)->node);				\
  		(work)->func = (fn);					\

  	} while (0)

  #define kthread_init_delayed_work(dwork, fn)				\
  	do {								\
  		kthread_init_work(&(dwork)->work, (fn));		\

  		timer_setup(&(dwork)->timer,				\

  			     kthread_delayed_work_timer_fn,		\
  			     TIMER_IRQSAFE);				\

  	} while (0)

  int kthread_worker_fn(void *worker_ptr);

  __printf(2, 3)

  struct kthread_worker *

  kthread_create_worker(unsigned int flags, const char namefmt[], ...);

  __printf(3, 4) struct kthread_worker *

  kthread_create_worker_on_cpu(int cpu, unsigned int flags,
  			     const char namefmt[], ...);

  bool kthread_queue_work(struct kthread_worker *worker,

  			struct kthread_work *work);

  
  bool kthread_queue_delayed_work(struct kthread_worker *worker,
  				struct kthread_delayed_work *dwork,
  				unsigned long delay);

  bool kthread_mod_delayed_work(struct kthread_worker *worker,
  			      struct kthread_delayed_work *dwork,
  			      unsigned long delay);

  void kthread_flush_work(struct kthread_work *work);
  void kthread_flush_worker(struct kthread_worker *worker);

  bool kthread_cancel_work_sync(struct kthread_work *work);
  bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);

  void kthread_destroy_worker(struct kthread_worker *worker);

  void kthread_use_mm(struct mm_struct *mm);
  void kthread_unuse_mm(struct mm_struct *mm);

  struct cgroup_subsys_state;

  #ifdef CONFIG_BLK_CGROUP

  void kthread_associate_blkcg(struct cgroup_subsys_state *css);
  struct cgroup_subsys_state *kthread_blkcg(void);
  #else
  static inline void kthread_associate_blkcg(struct cgroup_subsys_state *css) { }
  static inline struct cgroup_subsys_state *kthread_blkcg(void)
  {
  	return NULL;
  }
  #endif

  #endif /* _LINUX_KTHREAD_H */