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+/*
+ * BFQ-v7r8 for 4.0.0: data structures and common functions prototypes.
+ *
+ * Based on ideas and code from CFQ:
+ * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
+ *
+ * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
+ *		      Paolo Valente <paolo.valente@unimore.it>
+ *
+ * Copyright (C) 2010 Paolo Valente <paolo.valente@unimore.it>
+ */
+
+#ifndef _BFQ_H
+#define _BFQ_H
+
+#include <linux/blktrace_api.h>
+#include <linux/hrtimer.h>
+#include <linux/ioprio.h>
+#include <linux/rbtree.h>
+
+#define BFQ_IOPRIO_CLASSES	3
+#define BFQ_CL_IDLE_TIMEOUT	(HZ/5)
+
+#define BFQ_MIN_WEIGHT	1
+#define BFQ_MAX_WEIGHT	1000
+
+#define BFQ_DEFAULT_QUEUE_IOPRIO	4
+
+#define BFQ_DEFAULT_GRP_WEIGHT	10
+#define BFQ_DEFAULT_GRP_IOPRIO	0
+#define BFQ_DEFAULT_GRP_CLASS	IOPRIO_CLASS_BE
+
+struct bfq_entity;
+
+/**
+ * struct bfq_service_tree - per ioprio_class service tree.
+ * @active: tree for active entities (i.e., those backlogged).
+ * @idle: tree for idle entities (i.e., those not backlogged, with V <= F_i).
+ * @first_idle: idle entity with minimum F_i.
+ * @last_idle: idle entity with maximum F_i.
+ * @vtime: scheduler virtual time.
+ * @wsum: scheduler weight sum; active and idle entities contribute to it.
+ *
+ * Each service tree represents a B-WF2Q+ scheduler on its own.  Each
+ * ioprio_class has its own independent scheduler, and so its own
+ * bfq_service_tree.  All the fields are protected by the queue lock
+ * of the containing bfqd.
+ */
+struct bfq_service_tree {
+	struct rb_root active;
+	struct rb_root idle;
+
+	struct bfq_entity *first_idle;
+	struct bfq_entity *last_idle;
+
+	u64 vtime;
+	unsigned long wsum;
+};
+
+/**
+ * struct bfq_sched_data - multi-class scheduler.
+ * @in_service_entity: entity in service.
+ * @next_in_service: head-of-the-line entity in the scheduler.
+ * @service_tree: array of service trees, one per ioprio_class.
+ *
+ * bfq_sched_data is the basic scheduler queue.  It supports three
+ * ioprio_classes, and can be used either as a toplevel queue or as
+ * an intermediate queue on a hierarchical setup.
+ * @next_in_service points to the active entity of the sched_data
+ * service trees that will be scheduled next.
+ *
+ * The supported ioprio_classes are the same as in CFQ, in descending
+ * priority order, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE.
+ * Requests from higher priority queues are served before all the
+ * requests from lower priority queues; among requests of the same
+ * queue requests are served according to B-WF2Q+.
+ * All the fields are protected by the queue lock of the containing bfqd.
+ */
+struct bfq_sched_data {
+	struct bfq_entity *in_service_entity;
+	struct bfq_entity *next_in_service;
+	struct bfq_service_tree service_tree[BFQ_IOPRIO_CLASSES];
+};
+
+/**
+ * struct bfq_weight_counter - counter of the number of all active entities
+ *                             with a given weight.
+ * @weight: weight of the entities that this counter refers to.
+ * @num_active: number of active entities with this weight.
+ * @weights_node: weights tree member (see bfq_data's @queue_weights_tree
+ *                and @group_weights_tree).
+ */
+struct bfq_weight_counter {
+	short int weight;
+	unsigned int num_active;
+	struct rb_node weights_node;
+};
+
+/**
+ * struct bfq_entity - schedulable entity.
+ * @rb_node: service_tree member.
+ * @weight_counter: pointer to the weight counter associated with this entity.
+ * @on_st: flag, true if the entity is on a tree (either the active or
+ *         the idle one of its service_tree).
+ * @finish: B-WF2Q+ finish timestamp (aka F_i).
+ * @start: B-WF2Q+ start timestamp (aka S_i).
+ * @tree: tree the entity is enqueued into; %NULL if not on a tree.
+ * @min_start: minimum start time of the (active) subtree rooted at
+ *             this entity; used for O(log N) lookups into active trees.
+ * @service: service received during the last round of service.
+ * @budget: budget used to calculate F_i; F_i = S_i + @budget / @weight.
+ * @weight: weight of the queue
+ * @parent: parent entity, for hierarchical scheduling.
+ * @my_sched_data: for non-leaf nodes in the cgroup hierarchy, the
+ *                 associated scheduler queue, %NULL on leaf nodes.
+ * @sched_data: the scheduler queue this entity belongs to.
+ * @ioprio: the ioprio in use.
+ * @new_weight: when a weight change is requested, the new weight value.
+ * @orig_weight: original weight, used to implement weight boosting
+ * @new_ioprio: when an ioprio change is requested, the new ioprio value.
+ * @ioprio_class: the ioprio_class in use.
+ * @new_ioprio_class: when an ioprio_class change is requested, the new
+ *                    ioprio_class value.
+ * @ioprio_changed: flag, true when the user requested a weight, ioprio or
+ *                  ioprio_class change.
+ *
+ * A bfq_entity is used to represent either a bfq_queue (leaf node in the
+ * cgroup hierarchy) or a bfq_group into the upper level scheduler.  Each
+ * entity belongs to the sched_data of the parent group in the cgroup
+ * hierarchy.  Non-leaf entities have also their own sched_data, stored
+ * in @my_sched_data.
+ *
+ * Each entity stores independently its priority values; this would
+ * allow different weights on different devices, but this
+ * functionality is not exported to userspace by now.  Priorities and
+ * weights are updated lazily, first storing the new values into the
+ * new_* fields, then setting the @ioprio_changed flag.  As soon as
+ * there is a transition in the entity state that allows the priority
+ * update to take place the effective and the requested priority
+ * values are synchronized.
+ *
+ * Unless cgroups are used, the weight value is calculated from the
+ * ioprio to export the same interface as CFQ.  When dealing with
+ * ``well-behaved'' queues (i.e., queues that do not spend too much
+ * time to consume their budget and have true sequential behavior, and
+ * when there are no external factors breaking anticipation) the
+ * relative weights at each level of the cgroups hierarchy should be
+ * guaranteed.  All the fields are protected by the queue lock of the
+ * containing bfqd.
+ */
+struct bfq_entity {
+	struct rb_node rb_node;
+	struct bfq_weight_counter *weight_counter;
+
+	int on_st;
+
+	u64 finish;
+	u64 start;
+
+	struct rb_root *tree;
+
+	u64 min_start;
+
+	unsigned long service, budget;
+	unsigned short weight, new_weight;
+	unsigned short orig_weight;
+
+	struct bfq_entity *parent;
+
+	struct bfq_sched_data *my_sched_data;
+	struct bfq_sched_data *sched_data;
+
+	unsigned short ioprio, new_ioprio;
+	unsigned short ioprio_class, new_ioprio_class;
+
+	int ioprio_changed;
+};
+
+struct bfq_group;
+
+/**
+ * struct bfq_queue - leaf schedulable entity.
+ * @ref: reference counter.
+ * @bfqd: parent bfq_data.
+ * @new_bfqq: shared bfq_queue if queue is cooperating with
+ *           one or more other queues.
+ * @pos_node: request-position tree member (see bfq_data's @rq_pos_tree).
+ * @pos_root: request-position tree root (see bfq_data's @rq_pos_tree).
+ * @sort_list: sorted list of pending requests.
+ * @next_rq: if fifo isn't expired, next request to serve.
+ * @queued: nr of requests queued in @sort_list.
+ * @allocated: currently allocated requests.
+ * @meta_pending: pending metadata requests.
+ * @fifo: fifo list of requests in sort_list.
+ * @entity: entity representing this queue in the scheduler.
+ * @max_budget: maximum budget allowed from the feedback mechanism.
+ * @budget_timeout: budget expiration (in jiffies).
+ * @dispatched: number of requests on the dispatch list or inside driver.
+ * @flags: status flags.
+ * @bfqq_list: node for active/idle bfqq list inside our bfqd.
+ * @burst_list_node: node for the device's burst list.
+ * @seek_samples: number of seeks sampled
+ * @seek_total: sum of the distances of the seeks sampled
+ * @seek_mean: mean seek distance
+ * @last_request_pos: position of the last request enqueued
+ * @requests_within_timer: number of consecutive pairs of request completion
+ *                         and arrival, such that the queue becomes idle
+ *                         after the completion, but the next request arrives
+ *                         within an idle time slice; used only if the queue's
+ *                         IO_bound has been cleared.
+ * @pid: pid of the process owning the queue, used for logging purposes.
+ * @last_wr_start_finish: start time of the current weight-raising period if
+ *                        the @bfq-queue is being weight-raised, otherwise
+ *                        finish time of the last weight-raising period
+ * @wr_cur_max_time: current max raising time for this queue
+ * @soft_rt_next_start: minimum time instant such that, only if a new
+ *                      request is enqueued after this time instant in an
+ *                      idle @bfq_queue with no outstanding requests, then
+ *                      the task associated with the queue it is deemed as
+ *                      soft real-time (see the comments to the function
+ *                      bfq_bfqq_softrt_next_start())
+ * @last_idle_bklogged: time of the last transition of the @bfq_queue from
+ *                      idle to backlogged
+ * @service_from_backlogged: cumulative service received from the @bfq_queue
+ *                           since the last transition from idle to
+ *                           backlogged
+ * @bic: pointer to the bfq_io_cq owning the bfq_queue, set to %NULL if the
+ *	 queue is shared
+ *
+ * A bfq_queue is a leaf request queue; it can be associated with an
+ * io_context or more, if it  is  async or shared  between  cooperating
+ * processes. @cgroup holds a reference to the cgroup, to be sure that it
+ * does not disappear while a bfqq still references it (mostly to avoid
+ * races between request issuing and task migration followed by cgroup
+ * destruction).
+ * All the fields are protected by the queue lock of the containing bfqd.
+ */
+struct bfq_queue {
+	atomic_t ref;
+	struct bfq_data *bfqd;
+
+	/* fields for cooperating queues handling */
+	struct bfq_queue *new_bfqq;
+	struct rb_node pos_node;
+	struct rb_root *pos_root;
+
+	struct rb_root sort_list;
+	struct request *next_rq;
+	int queued[2];
+	int allocated[2];
+	int meta_pending;
+	struct list_head fifo;
+
+	struct bfq_entity entity;
+
+	unsigned long max_budget;
+	unsigned long budget_timeout;
+
+	int dispatched;
+
+	unsigned int flags;
+
+	struct list_head bfqq_list;
+
+	struct hlist_node burst_list_node;
+
+	unsigned int seek_samples;
+	u64 seek_total;
+	sector_t seek_mean;
+	sector_t last_request_pos;
+
+	unsigned int requests_within_timer;
+
+	pid_t pid;
+	struct bfq_io_cq *bic;
+
+	/* weight-raising fields */
+	unsigned long wr_cur_max_time;
+	unsigned long soft_rt_next_start;
+	unsigned long last_wr_start_finish;
+	unsigned int wr_coeff;
+	unsigned long last_idle_bklogged;
+	unsigned long service_from_backlogged;
+};
+
+/**
+ * struct bfq_ttime - per process thinktime stats.
+ * @ttime_total: total process thinktime
+ * @ttime_samples: number of thinktime samples
+ * @ttime_mean: average process thinktime
+ */
+struct bfq_ttime {
+	unsigned long last_end_request;
+
+	unsigned long ttime_total;
+	unsigned long ttime_samples;
+	unsigned long ttime_mean;
+};
+
+/**
+ * struct bfq_io_cq - per (request_queue, io_context) structure.
+ * @icq: associated io_cq structure
+ * @bfqq: array of two process queues, the sync and the async
+ * @ttime: associated @bfq_ttime struct
+ * @wr_time_left: snapshot of the time left before weight raising ends
+ *                for the sync queue associated to this process; this
+ *		  snapshot is taken to remember this value while the weight
+ *		  raising is suspended because the queue is merged with a
+ *		  shared queue, and is used to set @raising_cur_max_time
+ *		  when the queue is split from the shared queue and its
+ *		  weight is raised again
+ * @saved_idle_window: same purpose as the previous field for the idle
+ *                     window
+ * @saved_IO_bound: same purpose as the previous two fields for the I/O
+ *                  bound classification of a queue
+ * @saved_in_large_burst: same purpose as the previous fields for the
+ *                        value of the field keeping the queue's belonging
+ *                        to a large burst
+ * @was_in_burst_list: true if the queue belonged to a burst list
+ *                     before its merge with another cooperating queue
+ * @cooperations: counter of consecutive successful queue merges underwent
+ *                by any of the process' @bfq_queues
+ * @failed_cooperations: counter of consecutive failed queue merges of any
+ *                       of the process' @bfq_queues
+ */
+struct bfq_io_cq {
+	struct io_cq icq; /* must be the first member */
+	struct bfq_queue *bfqq[2];
+	struct bfq_ttime ttime;
+	int ioprio;
+
+	unsigned int wr_time_left;
+	bool saved_idle_window;
+	bool saved_IO_bound;
+
+	bool saved_in_large_burst;
+	bool was_in_burst_list;
+
+	unsigned int cooperations;
+	unsigned int failed_cooperations;
+};
+
+enum bfq_device_speed {
+	BFQ_BFQD_FAST,
+	BFQ_BFQD_SLOW,
+};
+
+/**
+ * struct bfq_data - per device data structure.
+ * @queue: request queue for the managed device.
+ * @root_group: root bfq_group for the device.
+ * @rq_pos_tree: rbtree sorted by next_request position, used when
+ *               determining if two or more queues have interleaving
+ *               requests (see bfq_close_cooperator()).
+ * @active_numerous_groups: number of bfq_groups containing more than one
+ *                          active @bfq_entity.
+ * @queue_weights_tree: rbtree of weight counters of @bfq_queues, sorted by
+ *                      weight. Used to keep track of whether all @bfq_queues
+ *                     have the same weight. The tree contains one counter
+ *                     for each distinct weight associated to some active
+ *                     and not weight-raised @bfq_queue (see the comments to
+ *                      the functions bfq_weights_tree_[add|remove] for
+ *                     further details).
+ * @group_weights_tree: rbtree of non-queue @bfq_entity weight counters, sorted
+ *                      by weight. Used to keep track of whether all
+ *                     @bfq_groups have the same weight. The tree contains
+ *                     one counter for each distinct weight associated to
+ *                     some active @bfq_group (see the comments to the
+ *                     functions bfq_weights_tree_[add|remove] for further
+ *                     details).
+ * @busy_queues: number of bfq_queues containing requests (including the
+ *		 queue in service, even if it is idling).
+ * @busy_in_flight_queues: number of @bfq_queues containing pending or
+ *                         in-flight requests, plus the @bfq_queue in
+ *                         service, even if idle but waiting for the
+ *                         possible arrival of its next sync request. This
+ *                         field is updated only if the device is rotational,
+ *                         but used only if the device is also NCQ-capable.
+ *                         The reason why the field is updated also for non-
+ *                         NCQ-capable rotational devices is related to the
+ *                         fact that the value of @hw_tag may be set also
+ *                         later than when busy_in_flight_queues may need to
+ *                         be incremented for the first time(s). Taking also
+ *                         this possibility into account, to avoid unbalanced
+ *                         increments/decrements, would imply more overhead
+ *                         than just updating busy_in_flight_queues
+ *                         regardless of the value of @hw_tag.
+ * @const_seeky_busy_in_flight_queues: number of constantly-seeky @bfq_queues
+ *                                     (that is, seeky queues that expired
+ *                                     for budget timeout at least once)
+ *                                     containing pending or in-flight
+ *                                     requests, including the in-service
+ *                                     @bfq_queue if constantly seeky. This
+ *                                     field is updated only if the device
+ *                                     is rotational, but used only if the
+ *                                     device is also NCQ-capable (see the
+ *                                     comments to @busy_in_flight_queues).
+ * @wr_busy_queues: number of weight-raised busy @bfq_queues.
+ * @queued: number of queued requests.
+ * @rq_in_driver: number of requests dispatched and waiting for completion.
+ * @sync_flight: number of sync requests in the driver.
+ * @max_rq_in_driver: max number of reqs in driver in the last
+ *                    @hw_tag_samples completed requests.
+ * @hw_tag_samples: nr of samples used to calculate hw_tag.
+ * @hw_tag: flag set to one if the driver is showing a queueing behavior.
+ * @budgets_assigned: number of budgets assigned.
+ * @idle_slice_timer: timer set when idling for the next sequential request
+ *                    from the queue in service.
+ * @unplug_work: delayed work to restart dispatching on the request queue.
+ * @in_service_queue: bfq_queue in service.
+ * @in_service_bic: bfq_io_cq (bic) associated with the @in_service_queue.
+ * @last_position: on-disk position of the last served request.
+ * @last_budget_start: beginning of the last budget.
+ * @last_idling_start: beginning of the last idle slice.
+ * @peak_rate: peak transfer rate observed for a budget.
+ * @peak_rate_samples: number of samples used to calculate @peak_rate.
+ * @bfq_max_budget: maximum budget allotted to a bfq_queue before
+ *                  rescheduling.
+ * @group_list: list of all the bfq_groups active on the device.
+ * @active_list: list of all the bfq_queues active on the device.
+ * @idle_list: list of all the bfq_queues idle on the device.
+ * @bfq_fifo_expire: timeout for async/sync requests; when it expires
+ *                   requests are served in fifo order.
+ * @bfq_back_penalty: weight of backward seeks wrt forward ones.
+ * @bfq_back_max: maximum allowed backward seek.
+ * @bfq_slice_idle: maximum idling time.
+ * @bfq_user_max_budget: user-configured max budget value
+ *                       (0 for auto-tuning).
+ * @bfq_max_budget_async_rq: maximum budget (in nr of requests) allotted to
+ *                           async queues.
+ * @bfq_timeout: timeout for bfq_queues to consume their budget; used to
+ *               to prevent seeky queues to impose long latencies to well
+ *               behaved ones (this also implies that seeky queues cannot
+ *               receive guarantees in the service domain; after a timeout
+ *               they are charged for the whole allocated budget, to try
+ *               to preserve a behavior reasonably fair among them, but
+ *               without service-domain guarantees).
+ * @bfq_coop_thresh: number of queue merges after which a @bfq_queue is
+ *                   no more granted any weight-raising.
+ * @bfq_failed_cooperations: number of consecutive failed cooperation
+ *                           chances after which weight-raising is restored
+ *                           to a queue subject to more than bfq_coop_thresh
+ *                           queue merges.
+ * @bfq_requests_within_timer: number of consecutive requests that must be
+ *                             issued within the idle time slice to set
+ *                             again idling to a queue which was marked as
+ *                             non-I/O-bound (see the definition of the
+ *                             IO_bound flag for further details).
+ * @last_ins_in_burst: last time at which a queue entered the current
+ *                     burst of queues being activated shortly after
+ *                     each other; for more details about this and the
+ *                     following parameters related to a burst of
+ *                     activations, see the comments to the function
+ *                     @bfq_handle_burst.
+ * @bfq_burst_interval: reference time interval used to decide whether a
+ *                      queue has been activated shortly after
+ *                      @last_ins_in_burst.
+ * @burst_size: number of queues in the current burst of queue activations.
+ * @bfq_large_burst_thresh: maximum burst size above which the current
+ * 			    queue-activation burst is deemed as 'large'.
+ * @large_burst: true if a large queue-activation burst is in progress.
+ * @burst_list: head of the burst list (as for the above fields, more details
+ * 		in the comments to the function bfq_handle_burst).
+ * @low_latency: if set to true, low-latency heuristics are enabled.
+ * @bfq_wr_coeff: maximum factor by which the weight of a weight-raised
+ *                queue is multiplied.
+ * @bfq_wr_max_time: maximum duration of a weight-raising period (jiffies).
+ * @bfq_wr_rt_max_time: maximum duration for soft real-time processes.
+ * @bfq_wr_min_idle_time: minimum idle period after which weight-raising
+ *			  may be reactivated for a queue (in jiffies).
+ * @bfq_wr_min_inter_arr_async: minimum period between request arrivals
+ *				after which weight-raising may be
+ *				reactivated for an already busy queue
+ *				(in jiffies).
+ * @bfq_wr_max_softrt_rate: max service-rate for a soft real-time queue,
+ *			    sectors per seconds.
+ * @RT_prod: cached value of the product R*T used for computing the maximum
+ *	     duration of the weight raising automatically.
+ * @device_speed: device-speed class for the low-latency heuristic.
+ * @oom_bfqq: fallback dummy bfqq for extreme OOM conditions.
+ *
+ * All the fields are protected by the @queue lock.
+ */
+struct bfq_data {
+	struct request_queue *queue;
+
+	struct bfq_group *root_group;
+	struct rb_root rq_pos_tree;
+
+#ifdef CONFIG_CGROUP_BFQIO
+	int active_numerous_groups;
+#endif
+
+	struct rb_root queue_weights_tree;
+	struct rb_root group_weights_tree;
+
+	int busy_queues;
+	int busy_in_flight_queues;
+	int const_seeky_busy_in_flight_queues;
+	int wr_busy_queues;
+	int queued;
+	int rq_in_driver;
+	int sync_flight;
+
+	int max_rq_in_driver;
+	int hw_tag_samples;
+	int hw_tag;
+
+	int budgets_assigned;
+
+	struct timer_list idle_slice_timer;
+	struct work_struct unplug_work;
+
+	struct bfq_queue *in_service_queue;
+	struct bfq_io_cq *in_service_bic;
+
+	sector_t last_position;
+
+	ktime_t last_budget_start;
+	ktime_t last_idling_start;
+	int peak_rate_samples;
+	u64 peak_rate;
+	unsigned long bfq_max_budget;
+
+	struct hlist_head group_list;
+	struct list_head active_list;
+	struct list_head idle_list;
+
+	unsigned int bfq_fifo_expire[2];
+	unsigned int bfq_back_penalty;
+	unsigned int bfq_back_max;
+	unsigned int bfq_slice_idle;
+	u64 bfq_class_idle_last_service;
+
+	unsigned int bfq_user_max_budget;
+	unsigned int bfq_max_budget_async_rq;
+	unsigned int bfq_timeout[2];
+
+	unsigned int bfq_coop_thresh;
+	unsigned int bfq_failed_cooperations;
+	unsigned int bfq_requests_within_timer;
+
+	unsigned long last_ins_in_burst;
+	unsigned long bfq_burst_interval;
+	int burst_size;
+	unsigned long bfq_large_burst_thresh;
+	bool large_burst;
+	struct hlist_head burst_list;
+
+	bool low_latency;
+
+	/* parameters of the low_latency heuristics */
+	unsigned int bfq_wr_coeff;
+	unsigned int bfq_wr_max_time;
+	unsigned int bfq_wr_rt_max_time;
+	unsigned int bfq_wr_min_idle_time;
+	unsigned long bfq_wr_min_inter_arr_async;
+	unsigned int bfq_wr_max_softrt_rate;
+	u64 RT_prod;
+	enum bfq_device_speed device_speed;
+
+	struct bfq_queue oom_bfqq;
+};
+
+enum bfqq_state_flags {
+	BFQ_BFQQ_FLAG_busy = 0,		/* has requests or is in service */
+	BFQ_BFQQ_FLAG_wait_request,	/* waiting for a request */
+	BFQ_BFQQ_FLAG_must_alloc,	/* must be allowed rq alloc */
+	BFQ_BFQQ_FLAG_fifo_expire,	/* FIFO checked in this slice */
+	BFQ_BFQQ_FLAG_idle_window,	/* slice idling enabled */
+	BFQ_BFQQ_FLAG_sync,		/* synchronous queue */
+	BFQ_BFQQ_FLAG_budget_new,	/* no completion with this budget */
+	BFQ_BFQQ_FLAG_IO_bound,		/*
+					 * bfqq has timed-out at least once
+					 * having consumed at most 2/10 of
+					 * its budget
+					 */
+	BFQ_BFQQ_FLAG_in_large_burst,	/*
+					 * bfqq activated in a large burst,
+					 * see comments to bfq_handle_burst.
+					 */
+	BFQ_BFQQ_FLAG_constantly_seeky,	/*
+					 * bfqq has proved to be slow and
+					 * seeky until budget timeout
+					 */
+	BFQ_BFQQ_FLAG_softrt_update,	/*
+					 * may need softrt-next-start
+					 * update
+					 */
+	BFQ_BFQQ_FLAG_coop,		/* bfqq is shared */
+	BFQ_BFQQ_FLAG_split_coop,	/* shared bfqq will be split */
+	BFQ_BFQQ_FLAG_just_split,	/* queue has just been split */
+};
+
+#define BFQ_BFQQ_FNS(name)						\
+static inline void bfq_mark_bfqq_##name(struct bfq_queue *bfqq)		\
+{									\
+	(bfqq)->flags |= (1 << BFQ_BFQQ_FLAG_##name);			\
+}									\
+static inline void bfq_clear_bfqq_##name(struct bfq_queue *bfqq)	\
+{									\
+	(bfqq)->flags &= ~(1 << BFQ_BFQQ_FLAG_##name);			\
+}									\
+static inline int bfq_bfqq_##name(const struct bfq_queue *bfqq)		\
+{									\
+	return ((bfqq)->flags & (1 << BFQ_BFQQ_FLAG_##name)) != 0;	\
+}
+
+BFQ_BFQQ_FNS(busy);
+BFQ_BFQQ_FNS(wait_request);
+BFQ_BFQQ_FNS(must_alloc);
+BFQ_BFQQ_FNS(fifo_expire);
+BFQ_BFQQ_FNS(idle_window);
+BFQ_BFQQ_FNS(sync);
+BFQ_BFQQ_FNS(budget_new);
+BFQ_BFQQ_FNS(IO_bound);
+BFQ_BFQQ_FNS(in_large_burst);
+BFQ_BFQQ_FNS(constantly_seeky);
+BFQ_BFQQ_FNS(coop);
+BFQ_BFQQ_FNS(split_coop);
+BFQ_BFQQ_FNS(just_split);
+BFQ_BFQQ_FNS(softrt_update);
+#undef BFQ_BFQQ_FNS
+
+/* Logging facilities. */
+#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) \
+	blk_add_trace_msg((bfqd)->queue, "bfq%d " fmt, (bfqq)->pid, ##args)
+
+#define bfq_log(bfqd, fmt, args...) \
+	blk_add_trace_msg((bfqd)->queue, "bfq " fmt, ##args)
+
+/* Expiration reasons. */
+enum bfqq_expiration {
+	BFQ_BFQQ_TOO_IDLE = 0,		/*
+					 * queue has been idling for
+					 * too long
+					 */
+	BFQ_BFQQ_BUDGET_TIMEOUT,	/* budget took too long to be used */
+	BFQ_BFQQ_BUDGET_EXHAUSTED,	/* budget consumed */
+	BFQ_BFQQ_NO_MORE_REQUESTS,	/* the queue has no more requests */
+};
+
+#ifdef CONFIG_CGROUP_BFQIO
+/**
+ * struct bfq_group - per (device, cgroup) data structure.
+ * @entity: schedulable entity to insert into the parent group sched_data.
+ * @sched_data: own sched_data, to contain child entities (they may be
+ *              both bfq_queues and bfq_groups).
+ * @group_node: node to be inserted into the bfqio_cgroup->group_data
+ *              list of the containing cgroup's bfqio_cgroup.
+ * @bfqd_node: node to be inserted into the @bfqd->group_list list
+ *             of the groups active on the same device; used for cleanup.
+ * @bfqd: the bfq_data for the device this group acts upon.
+ * @async_bfqq: array of async queues for all the tasks belonging to
+ *              the group, one queue per ioprio value per ioprio_class,
+ *              except for the idle class that has only one queue.
+ * @async_idle_bfqq: async queue for the idle class (ioprio is ignored).
+ * @my_entity: pointer to @entity, %NULL for the toplevel group; used
+ *             to avoid too many special cases during group creation/
+ *             migration.
+ * @active_entities: number of active entities belonging to the group;
+ *                   unused for the root group. Used to know whether there
+ *                   are groups with more than one active @bfq_entity
+ *                   (see the comments to the function
+ *                   bfq_bfqq_must_not_expire()).
+ *
+ * Each (device, cgroup) pair has its own bfq_group, i.e., for each cgroup
+ * there is a set of bfq_groups, each one collecting the lower-level
+ * entities belonging to the group that are acting on the same device.
+ *
+ * Locking works as follows:
+ *    o @group_node is protected by the bfqio_cgroup lock, and is accessed
+ *      via RCU from its readers.
+ *    o @bfqd is protected by the queue lock, RCU is used to access it
+ *      from the readers.
+ *    o All the other fields are protected by the @bfqd queue lock.
+ */
+struct bfq_group {
+	struct bfq_entity entity;
+	struct bfq_sched_data sched_data;
+
+	struct hlist_node group_node;
+	struct hlist_node bfqd_node;
+
+	void *bfqd;
+
+	struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR];
+	struct bfq_queue *async_idle_bfqq;
+
+	struct bfq_entity *my_entity;
+
+	int active_entities;
+};
+
+/**
+ * struct bfqio_cgroup - bfq cgroup data structure.
+ * @css: subsystem state for bfq in the containing cgroup.
+ * @online: flag marked when the subsystem is inserted.
+ * @weight: cgroup weight.
+ * @ioprio: cgroup ioprio.
+ * @ioprio_class: cgroup ioprio_class.
+ * @lock: spinlock that protects @ioprio, @ioprio_class and @group_data.
+ * @group_data: list containing the bfq_group belonging to this cgroup.
+ *
+ * @group_data is accessed using RCU, with @lock protecting the updates,
+ * @ioprio and @ioprio_class are protected by @lock.
+ */
+struct bfqio_cgroup {
+	struct cgroup_subsys_state css;
+	bool online;
+
+	unsigned short weight, ioprio, ioprio_class;
+
+	spinlock_t lock;
+	struct hlist_head group_data;
+};
+#else
+struct bfq_group {
+	struct bfq_sched_data sched_data;
+
+	struct bfq_queue *async_bfqq[2][IOPRIO_BE_NR];
+	struct bfq_queue *async_idle_bfqq;
+};
+#endif
+
+static inline struct bfq_service_tree *
+bfq_entity_service_tree(struct bfq_entity *entity)
+{
+	struct bfq_sched_data *sched_data = entity->sched_data;
+	unsigned int idx = entity->ioprio_class - 1;
+
+	BUG_ON(idx >= BFQ_IOPRIO_CLASSES);
+	BUG_ON(sched_data == NULL);
+
+	return sched_data->service_tree + idx;
+}
+
+static inline struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic,
+					    bool is_sync)
+{
+	return bic->bfqq[is_sync];
+}
+
+static inline void bic_set_bfqq(struct bfq_io_cq *bic,
+				struct bfq_queue *bfqq, bool is_sync)
+{
+	bic->bfqq[is_sync] = bfqq;
+}
+
+static inline struct bfq_data *bic_to_bfqd(struct bfq_io_cq *bic)
+{
+	return bic->icq.q->elevator->elevator_data;
+}
+
+/**
+ * bfq_get_bfqd_locked - get a lock to a bfqd using a RCU protected pointer.
+ * @ptr: a pointer to a bfqd.
+ * @flags: storage for the flags to be saved.
+ *
+ * This function allows bfqg->bfqd to be protected by the
+ * queue lock of the bfqd they reference; the pointer is dereferenced
+ * under RCU, so the storage for bfqd is assured to be safe as long
+ * as the RCU read side critical section does not end.  After the
+ * bfqd->queue->queue_lock is taken the pointer is rechecked, to be
+ * sure that no other writer accessed it.  If we raced with a writer,
+ * the function returns NULL, with the queue unlocked, otherwise it
+ * returns the dereferenced pointer, with the queue locked.
+ */
+static inline struct bfq_data *bfq_get_bfqd_locked(void **ptr,
+						   unsigned long *flags)
+{
+	struct bfq_data *bfqd;
+
+	rcu_read_lock();
+	bfqd = rcu_dereference(*(struct bfq_data **)ptr);
+
+	if (bfqd != NULL) {
+		spin_lock_irqsave(bfqd->queue->queue_lock, *flags);
+		if (*ptr == bfqd)
+			goto out;
+		spin_unlock_irqrestore(bfqd->queue->queue_lock, *flags);
+	}
+
+	bfqd = NULL;
+out:
+	rcu_read_unlock();
+	return bfqd;
+}
+
+static inline void bfq_put_bfqd_unlock(struct bfq_data *bfqd,
+				       unsigned long *flags)
+{
+	spin_unlock_irqrestore(bfqd->queue->queue_lock, *flags);
+}
+
+static void bfq_check_ioprio_change(struct bfq_io_cq *bic);
+static void bfq_put_queue(struct bfq_queue *bfqq);
+static void bfq_dispatch_insert(struct request_queue *q, struct request *rq);
+static struct bfq_queue *bfq_get_queue(struct bfq_data *bfqd,
+				       struct bfq_group *bfqg, int is_sync,
+				       struct bfq_io_cq *bic, gfp_t gfp_mask);
+static void bfq_end_wr_async_queues(struct bfq_data *bfqd,
+				    struct bfq_group *bfqg);
+static void bfq_put_async_queues(struct bfq_data *bfqd, struct bfq_group *bfqg);
+static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq);
+
+#endif /* _BFQ_H */