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

  #ifndef INT_BLK_MQ_H
  #define INT_BLK_MQ_H

  #include "blk-stat.h"

  #include "blk-mq-tag.h"

  struct blk_mq_tag_set;

  struct blk_mq_ctxs {
  	struct kobject kobj;
  	struct blk_mq_ctx __percpu	*queue_ctx;
  };

  /**
   * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
   */

  struct blk_mq_ctx {
  	struct {
  		spinlock_t		lock;

  		struct list_head	rq_lists[HCTX_MAX_TYPES];
  	} ____cacheline_aligned_in_smp;

  
  	unsigned int		cpu;

  	unsigned short		index_hw[HCTX_MAX_TYPES];

  	struct blk_mq_hw_ctx 	*hctxs[HCTX_MAX_TYPES];

  
  	/* 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 blk_mq_ctxs      *ctxs;

  	struct kobject		kobj;

  } ____cacheline_aligned_in_smp;

  void blk_mq_exit_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);

  bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
  			     unsigned int);

  void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
  				bool kick_requeue_list);

  void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);

  struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
  					struct blk_mq_ctx *start);

  
  /*
   * Internal helpers for allocating/freeing the request map
   */

  void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  		     unsigned int hctx_idx);

  void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);

  struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
  					unsigned int hctx_idx,
  					unsigned int nr_tags,

  					unsigned int reserved_tags,
  					unsigned int flags);

  int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
  		     unsigned int hctx_idx, unsigned int depth);

  
  /*
   * Internal helpers for request insertion into sw queues
   */
  void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
  				bool at_head);

  void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
  				  bool run_queue);

  void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
  				struct list_head *list);

  /* Used by blk_insert_cloned_request() to issue request directly */
  blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);

  void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
  				    struct list_head *list);

  /*
   * CPU -> queue mappings
   */

  extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);

  /*
   * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
   * @q: request queue

   * @type: the hctx type index

   * @cpu: CPU
   */
  static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,

  							  enum hctx_type type,

  							  unsigned int cpu)

  {

  	return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];

  }

  /*
   * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
   * @q: request queue
   * @flags: request command flags

   * @cpu: cpu ctx

   */
  static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
  						     unsigned int flags,

  						     struct blk_mq_ctx *ctx)

  {

  	enum hctx_type type = HCTX_TYPE_DEFAULT;

  	/*
  	 * The caller ensure that if REQ_HIPRI, poll must be enabled.
  	 */
  	if (flags & REQ_HIPRI)

  		type = HCTX_TYPE_POLL;

  	else if ((flags & REQ_OP_MASK) == REQ_OP_READ)

  		type = HCTX_TYPE_READ;

  	return ctx->hctxs[type];

  }

  /*

   * sysfs helpers
   */

  extern void blk_mq_sysfs_init(struct request_queue *q);

  extern void blk_mq_sysfs_deinit(struct request_queue *q);

  extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);

  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);

  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, raw_smp_processor_id());

  }

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

  	blk_mq_req_flags_t flags;

  	unsigned int shallow_depth;

  	unsigned int cmd_flags;

  
  	/* input & output parameter */
  	struct blk_mq_ctx *ctx;
  	struct blk_mq_hw_ctx *hctx;
  };

  static inline bool blk_mq_is_sbitmap_shared(unsigned int flags)
  {
  	return flags & BLK_MQ_F_TAG_HCTX_SHARED;
  }

  static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
  {

  	if (data->q->elevator)

  		return data->hctx->sched_tags;

  	return data->hctx->tags;
  }

  static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
  {
  	return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
  }

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

  unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part);

  void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
  			 unsigned int inflight[2]);

  static inline void blk_mq_put_dispatch_budget(struct request_queue *q)

  {

  	if (q->mq_ops->put_budget)

  		q->mq_ops->put_budget(q);

  }

  static inline bool blk_mq_get_dispatch_budget(struct request_queue *q)

  {

  	if (q->mq_ops->get_budget)

  		return q->mq_ops->get_budget(q);

  	return true;

  }

  static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
  {
  	if (blk_mq_is_sbitmap_shared(hctx->flags))
  		atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap);
  	else
  		atomic_inc(&hctx->nr_active);
  }
  
  static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
  {
  	if (blk_mq_is_sbitmap_shared(hctx->flags))
  		atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap);
  	else
  		atomic_dec(&hctx->nr_active);
  }
  
  static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
  {
  	if (blk_mq_is_sbitmap_shared(hctx->flags))
  		return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap);
  	return atomic_read(&hctx->nr_active);
  }

  static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
  					   struct request *rq)
  {
  	blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
  	rq->tag = BLK_MQ_NO_TAG;
  
  	if (rq->rq_flags & RQF_MQ_INFLIGHT) {
  		rq->rq_flags &= ~RQF_MQ_INFLIGHT;

  		__blk_mq_dec_active_requests(hctx);

  	}
  }
  
  static inline void blk_mq_put_driver_tag(struct request *rq)
  {
  	if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
  		return;
  
  	__blk_mq_put_driver_tag(rq->mq_hctx, rq);
  }

  static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)

  {
  	int cpu;
  
  	for_each_possible_cpu(cpu)

  		qmap->mq_map[cpu] = 0;

  }

  /*
   * blk_mq_plug() - Get caller context plug
   * @q: request queue
   * @bio : the bio being submitted by the caller context
   *
   * Plugging, by design, may delay the insertion of BIOs into the elevator in
   * order to increase BIO merging opportunities. This however can cause BIO
   * insertion order to change from the order in which submit_bio() is being
   * executed in the case of multiple contexts concurrently issuing BIOs to a
   * device, even if these context are synchronized to tightly control BIO issuing
   * order. While this is not a problem with regular block devices, this ordering
   * change can cause write BIO failures with zoned block devices as these
   * require sequential write patterns to zones. Prevent this from happening by
   * ignoring the plug state of a BIO issuing context if the target request queue
   * is for a zoned block device and the BIO to plug is a write operation.
   *
   * Return current->plug if the bio can be plugged and NULL otherwise
   */
  static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
  					   struct bio *bio)
  {
  	/*
  	 * For regular block devices or read operations, use the context plug
  	 * which may be NULL if blk_start_plug() was not executed.
  	 */
  	if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
  		return current->plug;
  
  	/* Zoned block device write operation case: do not plug the BIO */
  	return NULL;
  }

  /*
   * For shared tag users, we track the number of currently active users
   * and attempt to provide a fair share of the tag depth for each of them.
   */
  static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
  				  struct sbitmap_queue *bt)
  {
  	unsigned int depth, users;
  
  	if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
  		return true;

  
  	/*
  	 * Don't try dividing an ant
  	 */
  	if (bt->sb.depth == 1)
  		return true;

  	if (blk_mq_is_sbitmap_shared(hctx->flags)) {
  		struct request_queue *q = hctx->queue;
  		struct blk_mq_tag_set *set = q->tag_set;
  
  		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &q->queue_flags))
  			return true;
  		users = atomic_read(&set->active_queues_shared_sbitmap);
  	} else {
  		if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
  			return true;
  		users = atomic_read(&hctx->tags->active_queues);
  	}

  	if (!users)
  		return true;
  
  	/*
  	 * Allow at least some tags
  	 */
  	depth = max((bt->sb.depth + users - 1) / users, 4U);

  	return __blk_mq_active_requests(hctx) < depth;

  }

  #endif