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

  #ifndef BLK_INTERNAL_H
  #define BLK_INTERNAL_H

  #include <linux/idr.h>

  #include <linux/blk-mq.h>
  #include "blk-mq.h"

  /* Amount of time in which a process may batch requests */
  #define BLK_BATCH_TIME	(HZ/50UL)
  
  /* Number of requests a "batching" process may submit */
  #define BLK_BATCH_REQ	32

  /* Max future timer expiry for timeouts */
  #define BLK_MAX_TIMEOUT		(5 * HZ)

  #ifdef CONFIG_DEBUG_FS
  extern struct dentry *blk_debugfs_root;
  #endif

  struct blk_flush_queue {
  	unsigned int		flush_queue_delayed:1;
  	unsigned int		flush_pending_idx:1;
  	unsigned int		flush_running_idx:1;
  	unsigned long		flush_pending_since;
  	struct list_head	flush_queue[2];
  	struct list_head	flush_data_in_flight;
  	struct request		*flush_rq;

  
  	/*
  	 * flush_rq shares tag with this rq, both can't be active
  	 * at the same time
  	 */
  	struct request		*orig_rq;

  	spinlock_t		mq_flush_lock;
  };

  extern struct kmem_cache *blk_requestq_cachep;

  extern struct kmem_cache *request_cachep;

  extern struct kobj_type blk_queue_ktype;

  extern struct ida blk_queue_ida;

  /*
   * @q->queue_lock is set while a queue is being initialized. Since we know
   * that no other threads access the queue object before @q->queue_lock has
   * been set, it is safe to manipulate queue flags without holding the
   * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
   * blk_init_allocated_queue().
   */
  static inline void queue_lockdep_assert_held(struct request_queue *q)
  {
  	if (q->queue_lock)
  		lockdep_assert_held(q->queue_lock);
  }
  
  static inline void queue_flag_set_unlocked(unsigned int flag,
  					   struct request_queue *q)
  {
  	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
  	    kref_read(&q->kobj.kref))
  		lockdep_assert_held(q->queue_lock);
  	__set_bit(flag, &q->queue_flags);
  }
  
  static inline void queue_flag_clear_unlocked(unsigned int flag,
  					     struct request_queue *q)
  {
  	if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
  	    kref_read(&q->kobj.kref))
  		lockdep_assert_held(q->queue_lock);
  	__clear_bit(flag, &q->queue_flags);
  }
  
  static inline int queue_flag_test_and_clear(unsigned int flag,
  					    struct request_queue *q)
  {
  	queue_lockdep_assert_held(q);
  
  	if (test_bit(flag, &q->queue_flags)) {
  		__clear_bit(flag, &q->queue_flags);
  		return 1;
  	}
  
  	return 0;
  }
  
  static inline int queue_flag_test_and_set(unsigned int flag,
  					  struct request_queue *q)
  {
  	queue_lockdep_assert_held(q);
  
  	if (!test_bit(flag, &q->queue_flags)) {
  		__set_bit(flag, &q->queue_flags);
  		return 0;
  	}
  
  	return 1;
  }
  
  static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
  {
  	queue_lockdep_assert_held(q);
  	__set_bit(flag, &q->queue_flags);
  }
  
  static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
  {
  	queue_lockdep_assert_held(q);
  	__clear_bit(flag, &q->queue_flags);
  }

  static inline struct blk_flush_queue *blk_get_flush_queue(

  		struct request_queue *q, struct blk_mq_ctx *ctx)

  {

  	if (q->mq_ops)
  		return blk_mq_map_queue(q, ctx->cpu)->fq;
  	return q->fq;

  }

  static inline void __blk_get_queue(struct request_queue *q)
  {
  	kobject_get(&q->kobj);
  }

  struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
  		int node, int cmd_size);
  void blk_free_flush_queue(struct blk_flush_queue *q);

  int blk_init_rl(struct request_list *rl, struct request_queue *q,
  		gfp_t gfp_mask);

  void blk_exit_rl(struct request_queue *q, struct request_list *rl);

  void blk_exit_queue(struct request_queue *q);

  void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
  			struct bio *bio);

  void blk_queue_bypass_start(struct request_queue *q);
  void blk_queue_bypass_end(struct request_queue *q);

  void __blk_queue_free_tags(struct request_queue *q);

  void blk_freeze_queue(struct request_queue *q);
  
  static inline void blk_queue_enter_live(struct request_queue *q)
  {
  	/*
  	 * Given that running in generic_make_request() context
  	 * guarantees that a live reference against q_usage_counter has
  	 * been established, further references under that same context
  	 * need not check that the queue has been frozen (marked dead).
  	 */
  	percpu_ref_get(&q->q_usage_counter);
  }

  #ifdef CONFIG_BLK_DEV_INTEGRITY
  void blk_flush_integrity(void);

  bool __bio_integrity_endio(struct bio *);
  static inline bool bio_integrity_endio(struct bio *bio)
  {
  	if (bio_integrity(bio))
  		return __bio_integrity_endio(bio);
  	return true;
  }

  #else
  static inline void blk_flush_integrity(void)
  {
  }

  static inline bool bio_integrity_endio(struct bio *bio)
  {
  	return true;
  }

  #endif

  void blk_timeout_work(struct work_struct *work);

  unsigned long blk_rq_timeout(unsigned long timeout);

  void blk_add_timer(struct request *req);

  void blk_delete_timer(struct request *);

  
  bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
  			     struct bio *bio);
  bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
  			    struct bio *bio);

  bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
  		struct bio *bio);

  bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,

  			    unsigned int *request_count,
  			    struct request **same_queue_rq);

  unsigned int blk_plug_queued_count(struct request_queue *q);

  
  void blk_account_io_start(struct request *req, bool new_io);
  void blk_account_io_completion(struct request *req, unsigned int bytes);

  void blk_account_io_done(struct request *req, u64 now);

  /*

   * EH timer and IO completion will both attempt to 'grab' the request, make

   * sure that only one of them succeeds. Steal the bottom bit of the
   * __deadline field for this.

   */
  static inline int blk_mark_rq_complete(struct request *rq)
  {

  	return test_and_set_bit(0, &rq->__deadline);

  }
  
  static inline void blk_clear_rq_complete(struct request *rq)
  {

  	clear_bit(0, &rq->__deadline);
  }
  
  static inline bool blk_rq_is_complete(struct request *rq)
  {
  	return test_bit(0, &rq->__deadline);

  }

  /*
   * Internal elevator interface
   */

  #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)

  void blk_insert_flush(struct request *rq);

  static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
  {
  	struct elevator_queue *e = q->elevator;

  	if (e->type->ops.sq.elevator_activate_req_fn)
  		e->type->ops.sq.elevator_activate_req_fn(q, rq);

  }
  
  static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
  {
  	struct elevator_queue *e = q->elevator;

  	if (e->type->ops.sq.elevator_deactivate_req_fn)
  		e->type->ops.sq.elevator_deactivate_req_fn(q, rq);

  }

  int elevator_init(struct request_queue *);

  int elevator_init_mq(struct request_queue *q);

  int elevator_switch_mq(struct request_queue *q,
  			      struct elevator_type *new_e);

  void elevator_exit(struct request_queue *, struct elevator_queue *);

  int elv_register_queue(struct request_queue *q);
  void elv_unregister_queue(struct request_queue *q);

  struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);

  #ifdef CONFIG_FAIL_IO_TIMEOUT
  int blk_should_fake_timeout(struct request_queue *);
  ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
  ssize_t part_timeout_store(struct device *, struct device_attribute *,
  				const char *, size_t);
  #else
  static inline int blk_should_fake_timeout(struct request_queue *q)
  {
  	return 0;
  }
  #endif

  int ll_back_merge_fn(struct request_queue *q, struct request *req,
  		     struct bio *bio);
  int ll_front_merge_fn(struct request_queue *q, struct request *req, 
  		      struct bio *bio);

  struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
  struct request *attempt_front_merge(struct request_queue *q, struct request *rq);

  int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
  				struct request *next);

  void blk_recalc_rq_segments(struct request *rq);

  void blk_rq_set_mixed_merge(struct request *rq);

  bool blk_rq_merge_ok(struct request *rq, struct bio *bio);

  enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);

  void blk_queue_congestion_threshold(struct request_queue *q);

  int blk_dev_init(void);

  /*
   * Return the threshold (number of used requests) at which the queue is
   * considered to be congested.  It include a little hysteresis to keep the
   * context switch rate down.
   */
  static inline int queue_congestion_on_threshold(struct request_queue *q)
  {
  	return q->nr_congestion_on;
  }
  
  /*
   * The threshold at which a queue is considered to be uncongested
   */
  static inline int queue_congestion_off_threshold(struct request_queue *q)
  {
  	return q->nr_congestion_off;
  }

  extern int blk_update_nr_requests(struct request_queue *, unsigned int);

  /*
   * Contribute to IO statistics IFF:
   *
   *	a) it's attached to a gendisk, and
   *	b) the queue had IO stats enabled when this request was started, and

   *	c) it's a file system request

   */

  static inline bool blk_do_io_stat(struct request *rq)

  {

  	return rq->rq_disk &&

  	       (rq->rq_flags & RQF_IO_STAT) &&

  		!blk_rq_is_passthrough(rq);

  }

  static inline void req_set_nomerge(struct request_queue *q, struct request *req)
  {
  	req->cmd_flags |= REQ_NOMERGE;
  	if (req == q->last_merge)
  		q->last_merge = NULL;
  }

  /*

   * Steal a bit from this field for legacy IO path atomic IO marking. Note that
   * setting the deadline clears the bottom bit, potentially clearing the
   * completed bit. The user has to be OK with this (current ones are fine).
   */
  static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
  {
  	rq->__deadline = time & ~0x1UL;
  }
  
  static inline unsigned long blk_rq_deadline(struct request *rq)
  {
  	return rq->__deadline & ~0x1UL;
  }
  
  /*

   * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
   * is defined as 'unsigned int', meantime it has to aligned to with logical
   * block size which is the minimum accepted unit by hardware.
   */
  static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
  {
  	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
  }
  
  /*

   * Internal io_context interface
   */
  void get_io_context(struct io_context *ioc);

  struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);

  struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
  			     gfp_t gfp_mask);

  void ioc_clear_queue(struct request_queue *q);

  int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);

  
  /**

   * rq_ioc - determine io_context for request allocation
   * @bio: request being allocated is for this bio (can be %NULL)
   *
   * Determine io_context to use for request allocation for @bio.  May return
   * %NULL if %current->io_context doesn't exist.
   */
  static inline struct io_context *rq_ioc(struct bio *bio)
  {
  #ifdef CONFIG_BLK_CGROUP
  	if (bio && bio->bi_ioc)
  		return bio->bi_ioc;
  #endif
  	return current->io_context;
  }
  
  /**

   * create_io_context - try to create task->io_context

   * @gfp_mask: allocation mask
   * @node: allocation node
   *

   * If %current->io_context is %NULL, allocate a new io_context and install
   * it.  Returns the current %current->io_context which may be %NULL if
   * allocation failed.

   *
   * Note that this function can't be called with IRQ disabled because

   * task_lock which protects %current->io_context is IRQ-unsafe.

   */

  static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)

  {
  	WARN_ON_ONCE(irqs_disabled());

  	if (unlikely(!current->io_context))
  		create_task_io_context(current, gfp_mask, node);
  	return current->io_context;

  }
  
  /*
   * Internal throttling interface
   */

  #ifdef CONFIG_BLK_DEV_THROTTLING

  extern void blk_throtl_drain(struct request_queue *q);

  extern int blk_throtl_init(struct request_queue *q);
  extern void blk_throtl_exit(struct request_queue *q);

  extern void blk_throtl_register_queue(struct request_queue *q);

  #else /* CONFIG_BLK_DEV_THROTTLING */

  static inline void blk_throtl_drain(struct request_queue *q) { }

  static inline int blk_throtl_init(struct request_queue *q) { return 0; }
  static inline void blk_throtl_exit(struct request_queue *q) { }

  static inline void blk_throtl_register_queue(struct request_queue *q) { }

  #endif /* CONFIG_BLK_DEV_THROTTLING */

  #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
  extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
  extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
  	const char *page, size_t count);

  extern void blk_throtl_bio_endio(struct bio *bio);

  extern void blk_throtl_stat_add(struct request *rq, u64 time);

  #else
  static inline void blk_throtl_bio_endio(struct bio *bio) { }

  static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }

  #endif

  #ifdef CONFIG_BOUNCE
  extern int init_emergency_isa_pool(void);
  extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
  #else
  static inline int init_emergency_isa_pool(void)
  {
  	return 0;
  }
  static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
  {
  }
  #endif /* CONFIG_BOUNCE */

  extern void blk_drain_queue(struct request_queue *q);

  #ifdef CONFIG_BLK_CGROUP_IOLATENCY
  extern int blk_iolatency_init(struct request_queue *q);
  #else
  static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
  #endif

  #endif /* BLK_INTERNAL_H */