#ifndef INT_BLK_MQ_H
  #define INT_BLK_MQ_H

  struct blk_mq_tag_set;

  struct blk_mq_ctx {
  	struct {
  		spinlock_t		lock;
  		struct list_head	rq_list;
  	}  ____cacheline_aligned_in_smp;
  
  	unsigned int		cpu;
  	unsigned int		index_hw;

  
  	/* incremented at dispatch time */
  	unsigned long		rq_dispatched[2];
  	unsigned long		rq_merged;
  
  	/* incremented at completion time */
  	unsigned long		____cacheline_aligned_in_smp rq_completed[2];
  
  	struct request_queue	*queue;
  	struct kobject		kobj;

  } ____cacheline_aligned_in_smp;

  void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);

  void blk_mq_freeze_queue(struct request_queue *q);

  void blk_mq_free_queue(struct request_queue *q);

  int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);

  void blk_mq_wake_waiters(struct request_queue *q);

  
  /*
   * CPU hotplug helpers
   */

  void blk_mq_enable_hotplug(void);
  void blk_mq_disable_hotplug(void);

  
  /*
   * CPU -> queue mappings
   */

  int blk_mq_map_queues(struct blk_mq_tag_set *set);

  extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);

  static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  		int cpu)
  {
  	return q->queue_hw_ctx[q->mq_map[cpu]];
  }

  /*

   * sysfs helpers
   */
  extern int blk_mq_sysfs_register(struct request_queue *q);
  extern void blk_mq_sysfs_unregister(struct request_queue *q);

  extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);

  extern void blk_mq_rq_timed_out(struct request *req, bool reserved);

  void blk_mq_release(struct request_queue *q);

  static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
  					   unsigned int cpu)
  {
  	return per_cpu_ptr(q->queue_ctx, cpu);
  }
  
  /*
   * This assumes per-cpu software queueing queues. They could be per-node
   * as well, for instance. For now this is hardcoded as-is. Note that we don't
   * care about preemption, since we know the ctx's are persistent. This does
   * mean that we can't rely on ctx always matching the currently running CPU.
   */
  static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
  {
  	return __blk_mq_get_ctx(q, get_cpu());
  }
  
  static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
  {
  	put_cpu();
  }

  struct blk_mq_alloc_data {
  	/* input parameter */
  	struct request_queue *q;

  	unsigned int flags;

  
  	/* input & output parameter */
  	struct blk_mq_ctx *ctx;
  	struct blk_mq_hw_ctx *hctx;
  };
  
  static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,

  		struct request_queue *q, unsigned int flags,
  		struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)

  {
  	data->q = q;

  	data->flags = flags;

  	data->ctx = ctx;
  	data->hctx = hctx;
  }

  static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
  {
  	return hctx->nr_ctx && hctx->tags;
  }

  #endif