#ifndef _LINUX_IRQ_WORK_H
  #define _LINUX_IRQ_WORK_H

  #include <linux/llist.h>

  /*
   * An entry can be in one of four states:
   *
   * free	     NULL, 0 -> {claimed}       : free to be used
   * claimed   NULL, 3 -> {pending}       : claimed to be enqueued
   * pending   next, 3 -> {busy}          : queued, pending callback
   * busy      NULL, 2 -> {free, claimed} : callback in progress, can be claimed
   */
  
  #define IRQ_WORK_PENDING	1UL
  #define IRQ_WORK_BUSY		2UL
  #define IRQ_WORK_FLAGS		3UL
  #define IRQ_WORK_LAZY		4UL /* Doesn't want IPI, wait for tick */

  struct irq_work {

  	unsigned long flags;
  	struct llist_node llnode;

  	void (*func)(struct irq_work *);
  };
  
  static inline

  void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))

  {

  	work->flags = 0;
  	work->func = func;

  }

  #define DEFINE_IRQ_WORK(name, _f) struct irq_work name = { .func = (_f), }

  bool irq_work_queue(struct irq_work *work);

  
  #ifdef CONFIG_SMP
  bool irq_work_queue_on(struct irq_work *work, int cpu);
  #endif

  void irq_work_tick(void);

  void irq_work_sync(struct irq_work *work);

  #ifdef CONFIG_IRQ_WORK

  #include <asm/irq_work.h>

  void irq_work_run(void);

  bool irq_work_needs_cpu(void);
  #else

  static inline bool irq_work_needs_cpu(void) { return false; }

  static inline void irq_work_run(void) { }

  #endif

  #endif /* _LINUX_IRQ_WORK_H */