/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLK_MQ_H
#define BLK_MQ_H
#include <linux/blkdev.h>
#include <linux/sbitmap.h>
#include <linux/lockdep.h>
#include <linux/scatterlist.h>
#include <linux/prefetch.h>
#include <linux/srcu.h>
#include <linux/rw_hint.h>
struct blk_mq_tags;
struct blk_flush_queue;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_DEFAULT_RQ 128
enum rq_end_io_ret {
RQ_END_IO_NONE,
RQ_END_IO_FREE,
};
typedef enum rq_end_io_ret (rq_end_io_fn)(struct request *, blk_status_t);
/*
* request flags */
typedef __u32 __bitwise req_flags_t;
/* Keep rqf_name[] in sync with the definitions below */
enum {
/* drive already may have started this one */
__RQF_STARTED,
/* request for flush sequence */
__RQF_FLUSH_SEQ,
/* merge of different types, fail separately */
__RQF_MIXED_MERGE,
/* don't call prep for this one */
__RQF_DONTPREP,
/* use hctx->sched_tags */
__RQF_SCHED_TAGS,
/* use an I/O scheduler for this request */
__RQF_USE_SCHED,
/* vaguely specified driver internal error. Ignored by block layer */
__RQF_FAILED,
/* don't warn about errors */
__RQF_QUIET,
/* account into disk and partition IO statistics */
__RQF_IO_STAT,
/* runtime pm request */
__RQF_PM,
/* on IO scheduler merge hash */
__RQF_HASHED,
/* track IO completion time */
__RQF_STATS,
/* Look at ->special_vec for the actual data payload instead of the
bio chain. */
__RQF_SPECIAL_PAYLOAD,
/* request completion needs to be signaled to zone write plugging. */
__RQF_ZONE_WRITE_PLUGGING,
/* ->timeout has been called, don't expire again */
__RQF_TIMED_OUT,
__RQF_RESV,
__RQF_BITS
};
#define RQF_STARTED ((__force req_flags_t)(1 << __RQF_STARTED))
#define RQF_FLUSH_SEQ ((__force req_flags_t)(1 << __RQF_FLUSH_SEQ))
#define RQF_MIXED_MERGE ((__force req_flags_t)(1 << __RQF_MIXED_MERGE))
#define RQF_DONTPREP ((__force req_flags_t)(1 << __RQF_DONTPREP))
#define RQF_SCHED_TAGS ((__force req_flags_t)(1 << __RQF_SCHED_TAGS))
#define RQF_USE_SCHED ((__force req_flags_t)(1 << __RQF_USE_SCHED))
#define RQF_FAILED ((__force req_flags_t)(1 << __RQF_FAILED))
#define RQF_QUIET ((__force req_flags_t)(1 << __RQF_QUIET))
#define RQF_IO_STAT ((__force req_flags_t)(1 << __RQF_IO_STAT))
#define RQF_PM ((__force req_flags_t)(1 << __RQF_PM))
#define RQF_HASHED ((__force req_flags_t)(1 << __RQF_HASHED))
#define RQF_STATS ((__force req_flags_t)(1 << __RQF_STATS))
#define RQF_SPECIAL_PAYLOAD \
((__force req_flags_t)(1 << __RQF_SPECIAL_PAYLOAD))
#define RQF_ZONE_WRITE_PLUGGING \
((__force req_flags_t)(1 << __RQF_ZONE_WRITE_PLUGGING))
#define RQF_TIMED_OUT ((__force req_flags_t)(1 << __RQF_TIMED_OUT))
#define RQF_RESV ((__force req_flags_t)(1 << __RQF_RESV))
/* flags that prevent us from merging requests: */
#define RQF_NOMERGE_FLAGS \
(RQF_STARTED | RQF_FLUSH_SEQ | RQF_SPECIAL_PAYLOAD)
enum mq_rq_state {
MQ_RQ_IDLE = 0,
MQ_RQ_IN_FLIGHT = 1,
MQ_RQ_COMPLETE = 2,
};
/*
* Try to put the fields that are referenced together in the same cacheline.
*
* If you modify this structure, make sure to update blk_rq_init() and
* especially blk_mq_rq_ctx_init() to take care of the added fields.
*/
struct request {
struct request_queue *q;
struct blk_mq_ctx *mq_ctx;
struct blk_mq_hw_ctx *mq_hctx;
blk_opf_t cmd_flags; /* op and common flags */
req_flags_t rq_flags;
int tag;
int internal_tag;
unsigned int timeout;
/* the following two fields are internal, NEVER access directly */
unsigned int __data_len; /* total data len */
sector_t __sector; /* sector cursor */
struct bio *bio;
struct bio *biotail;
union {
struct list_head queuelist;
struct request *rq_next;
};
struct block_device *part;
#ifdef CONFIG_BLK_RQ_ALLOC_TIME
/* Time that the first bio started allocating this request. */
u64 alloc_time_ns;
#endif
/* Time that this request was allocated for this IO. */
u64 start_time_ns;
/* Time that I/O was submitted to the device. */
u64 io_start_time_ns;
#ifdef CONFIG_BLK_WBT
unsigned short wbt_flags;
#endif
/*
* rq sectors used for blk stats. It has the same value
* with blk_rq_sectors(rq), except that it never be zeroed
* by completion.
*/
unsigned short stats_sectors;
/*
* Number of scatter-gather DMA addr+len pairs after
* physical address coalescing is performed.
*/
unsigned short nr_phys_segments;
unsigned short nr_integrity_segments;
#ifdef CONFIG_BLK_INLINE_ENCRYPTION
struct bio_crypt_ctx *crypt_ctx;
struct blk_crypto_keyslot *crypt_keyslot;
#endif
enum rw_hint write_hint;
unsigned short ioprio;
enum mq_rq_state state;
atomic_t ref;
unsigned long deadline;
/*
* The hash is used inside the scheduler, and killed once the
* request reaches the dispatch list. The ipi_list is only used
* to queue the request for softirq completion, which is long
* after the request has been unhashed (and even removed from
* the dispatch list).
*/
union {
struct hlist_node hash; /* merge hash */
struct llist_node ipi_list;
};
/*
* The rb_node is only used inside the io scheduler, requests
* are pruned when moved to the dispatch queue. special_vec must
* only be used if RQF_SPECIAL_PAYLOAD is set, and those cannot be
* insert into an IO scheduler.
*/
union {
struct rb_node rb_node; /* sort/lookup */
struct bio_vec special_vec;
};
/*
* Three pointers are available for the IO schedulers, if they need
* more they have to dynamically allocate it.
*/
struct {
struct io_cq *icq;
void *priv[2];
} elv;
struct {
unsigned int seq;
rq_end_io_fn *saved_end_io;
} flush;
u64 fifo_time;
/*
* completion callback.
*/
rq_end_io_fn *end_io;
void *end_io_data;
};
static inline enum req_op req_op(const struct request *req)
{
return req->cmd_flags & REQ_OP_MASK;
}
static inline bool blk_rq_is_passthrough(struct request *rq)
{
return blk_op_is_passthrough(rq->cmd_flags);
}
static inline unsigned short req_get_ioprio(struct request *req)
{
return req->ioprio;
}
#define rq_data_dir(rq) (op_is_write(req_op(rq)) ? WRITE : READ)
#define rq_dma_dir(rq) \
(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
#define rq_list_add(listptr, rq) do { \
(rq)->rq_next = *(listptr); \
*(listptr) = rq; \
} while (0)
#define rq_list_add_tail(lastpptr, rq) do { \
(rq)->rq_next = NULL; \
**(lastpptr) = rq; \
*(lastpptr) = &rq->rq_next; \
} while (0)
#define rq_list_pop(listptr) \
({ \
struct request *__req = NULL; \
if ((listptr) && *(listptr)) { \
__req = *(listptr); \
*(listptr) = __req->rq_next; \
} \
__req; \
})
#define rq_list_peek(listptr) \
({ \
struct request *__req = NULL; \
if ((listptr) && *(listptr)) \
__req = *(listptr); \
__req; \
})
#define rq_list_for_each(listptr, pos) \
for (pos = rq_list_peek((listptr)); pos; pos = rq_list_next(pos))
#define rq_list_for_each_safe(listptr, pos, nxt) \
for (pos = rq_list_peek((listptr)), nxt = rq_list_next(pos); \
pos; pos = nxt, nxt = pos ? rq_list_next(pos) : NULL)
#define rq_list_next(rq) (rq)->rq_next
#define rq_list_empty(list) ((list) == (struct request *) NULL)
/**
* rq_list_move() - move a struct request from one list to another
* @src: The source list @rq is currently in
* @dst: The destination list that @rq will be appended to
* @rq: The request to move
* @prev: The request preceding @rq in @src (NULL if @rq is the head)
*/
static inline void rq_list_move(struct request **src, struct request **dst,
struct request *rq, struct request *prev)
{
if (prev)
prev->rq_next = rq->rq_next;
else
*src = rq->rq_next;
rq_list_add(dst, rq);
}
/**
* enum blk_eh_timer_return - How the timeout handler should proceed
* @BLK_EH_DONE: The block driver completed the command or will complete it at
* a later time.
* @BLK_EH_RESET_TIMER: Reset the request timer and continue waiting for the
* request to complete.
*/
enum blk_eh_timer_return {
BLK_EH_DONE,
BLK_EH_RESET_TIMER,
};
/* Keep alloc_policy_name[] in sync with the definitions below */
enum {
BLK_TAG_ALLOC_FIFO, /* allocate starting from 0 */
BLK_TAG_ALLOC_RR, /* allocate starting from last allocated tag */
BLK_TAG_ALLOC_MAX
};
/**
* struct blk_mq_hw_ctx - State for a hardware queue facing the hardware
* block device
*/
struct blk_mq_hw_ctx {
struct {
/** @lock: Protects the dispatch list. */
spinlock_t lock;
/**
* @dispatch: Used for requests that are ready to be
* dispatched to the hardware but for some reason (e.g. lack of
* resources) could not be sent to the hardware. As soon as the
* driver can send new requests, requests at this list will
* be sent first for a fairer dispatch.
*/
struct list_head dispatch;
/**
* @state: BLK_MQ_S_* flags. Defines the state of the hw
* queue (active, scheduled to restart, stopped).
*/
unsigned long state;
} ____cacheline_aligned_in_smp;
/**
* @run_work: Used for scheduling a hardware queue run at a later time.
*/
struct delayed_work run_work;
/** @cpumask: Map of available CPUs where this hctx can run. */
cpumask_var_t cpumask;
/**
* @next_cpu: Used by blk_mq_hctx_next_cpu() for round-robin CPU
* selection from @cpumask.
*/
int next_cpu;
/**
* @next_cpu_batch: Counter of how many works left in the batch before
* changing to the next CPU.
*/
int next_cpu_batch;
/** @flags: BLK_MQ_F_* flags. Defines the behaviour of the queue. */
unsigned long flags;
/**
* @sched_data: Pointer owned by the IO scheduler attached to a request
* queue. It's up to the IO scheduler how to use this pointer.
*/
void *sched_data;
/**
* @queue: Pointer to the request queue that owns this hardware context.
*/
struct request_queue *queue;
/** @fq: Queue of requests that need to perform a flush operation. */
struct blk_flush_queue *fq;
/**
* @driver_data: Pointer to data owned by the block driver that created
* this hctx
*/
void *driver_data;
/**
* @ctx_map: Bitmap for each software queue. If bit is on, there is a
* pending request in that software queue.
*/
struct sbitmap ctx_map;
/**
* @dispatch_from: Software queue to be used when no scheduler was
* selected.
*/
struct blk_mq_ctx *dispatch_from;
/**
* @dispatch_busy: Number used by blk_mq_update_dispatch_busy() to
* decide if the hw_queue is busy using Exponential Weighted Moving
* Average algorithm.
*/
unsigned int dispatch_busy;
/** @type: HCTX_TYPE_* flags. Type of hardware queue. */
unsigned short type;
/** @nr_ctx: Number of software queues. */
unsigned short nr_ctx;
/** @ctxs: Array of software queues. */
struct blk_mq_ctx **ctxs;
/** @dispatch_wait_lock: Lock for dispatch_wait queue. */
spinlock_t dispatch_wait_lock;
/**
* @dispatch_wait: Waitqueue to put requests when there is no tag
* available at the moment, to wait for another try in the future.
*/
wait_queue_entry_t dispatch_wait;
/**
* @wait_index: Index of next available dispatch_wait queue to insert
* requests.
*/
atomic_t wait_index;
/**
* @tags: Tags owned by the block driver. A tag at this set is only
* assigned when a request is dispatched from a hardware queue.
*/
struct blk_mq_tags *tags;
/**
* @sched_tags: Tags owned by I/O scheduler. If there is an I/O
* scheduler associated with a request queue, a tag is assigned when
* that request is allocated. Else, this member is not used.
*/
struct blk_mq_tags *sched_tags;
/** @numa_node: NUMA node the storage adapter has been connected to. */
unsigned int numa_node;
/** @queue_num: Index of this hardware queue. */
unsigned int queue_num;
/**
* @nr_active: Number of active requests. Only used when a tag set is
* shared across request queues.
*/
atomic_t nr_active;
/** @cpuhp_online: List to store request if CPU is going to die */
struct hlist_node cpuhp_online;
/** @cpuhp_dead: List to store request if some CPU die. */
struct hlist_node cpuhp_dead;
/** @kobj: Kernel object for sysfs. */
struct kobject kobj;
#ifdef CONFIG_BLK_DEBUG_FS
/**
* @debugfs_dir: debugfs directory for this hardware queue. Named
* as cpu<cpu_number>.
*/
struct dentry *debugfs_dir;
/** @sched_debugfs_dir: debugfs directory for the scheduler. */
struct dentry *sched_debugfs_dir;
#endif
/**
* @hctx_list: if this hctx is not in use, this is an entry in
* q->unused_hctx_list.
*/
struct list_head hctx_list;
};
/**
* struct blk_mq_queue_map - Map software queues to hardware queues
* @mq_map: CPU ID to hardware queue index map. This is an array
* with nr_cpu_ids elements. Each element has a value in the range
* [@queue_offset, @queue_offset + @nr_queues).
* @nr_queues: Number of hardware queues to map CPU IDs onto.
* @queue_offset: First hardware queue to map onto. Used by the PCIe NVMe
* driver to map each hardware queue type (enum hctx_type) onto a distinct
* set of hardware queues.
*/
struct blk_mq_queue_map {
unsigned int *mq_map;
unsigned int nr_queues;
unsigned int queue_offset;
};
/**
* enum hctx_type - Type of hardware queue
* @HCTX_TYPE_DEFAULT: All I/O not otherwise accounted for.
* @HCTX_TYPE_READ: Just for READ I/O.
* @HCTX_TYPE_POLL: Polled I/O of any kind.
* @HCTX_MAX_TYPES: Number of types of hctx.
*/
enum hctx_type {
HCTX_TYPE_DEFAULT,
HCTX_TYPE_READ,
HCTX_TYPE_POLL,
HCTX_MAX_TYPES,
};
/**
* struct blk_mq_tag_set - tag set that can be shared between request queues
* @ops: Pointers to functions that implement block driver behavior.
* @map: One or more ctx -> hctx mappings. One map exists for each
* hardware queue type (enum hctx_type) that the driver wishes
* to support. There are no restrictions on maps being of the
* same size, and it's perfectly legal to share maps between
* types.
* @nr_maps: Number of elements in the @map array. A number in the range
* [1, HCTX_MAX_TYPES].
* @nr_hw_queues: Number of hardware queues supported by the block driver that
* owns this data structure.
* @queue_depth: Number of tags per hardware queue, reserved tags included.
* @reserved_tags: Number of tags to set aside for BLK_MQ_REQ_RESERVED tag
* allocations.
* @cmd_size: Number of additional bytes to allocate per request. The block
* driver owns these additional bytes.
* @numa_node: NUMA node the storage adapter has been connected to.
* @timeout: Request processing timeout in jiffies.
* @flags: Zero or more BLK_MQ_F_* flags.
* @driver_data: Pointer to data owned by the block driver that created this
* tag set.
* @tags: Tag sets. One tag set per hardware queue. Has @nr_hw_queues
* elements.
* @shared_tags:
* Shared set of tags. Has @nr_hw_queues elements. If set,
* shared by all @tags.
* @tag_list_lock: Serializes tag_list accesses.
* @tag_list: List of the request queues that use this tag set. See also
* request_queue.tag_set_list.
* @srcu: Use as lock when type of the request queue is blocking
* (BLK_MQ_F_BLOCKING).
*/
struct blk_mq_tag_set {
const struct blk_mq_ops *ops;
struct blk_mq_queue_map map[HCTX_MAX_TYPES];
unsigned int nr_maps;
unsigned int nr_hw_queues;
unsigned int queue_depth;
unsigned int reserved_tags;
unsigned int cmd_size;
int numa_node;
unsigned int timeout;
unsigned int flags;
void *driver_data;
struct blk_mq_tags **tags;
struct blk_mq_tags *shared_tags;
struct mutex tag_list_lock;
struct list_head tag_list;
struct srcu_struct *srcu;
};
/**
* struct blk_mq_queue_data - Data about a request inserted in a queue
*
* @rq: Request pointer.
* @last: If it is the last request in the queue.
*/
struct blk_mq_queue_data {
struct request *rq;
bool last;
};
typedef bool (busy_tag_iter_fn)(struct request *, void *);
/**
* struct blk_mq_ops - Callback functions that implements block driver
* behaviour.
*/
struct blk_mq_ops {
/**
* @queue_rq: Queue a new request from block IO.
*/
blk_status_t (*queue_rq)(struct blk_mq_hw_ctx *,
const struct blk_mq_queue_data *);
/**
* @commit_rqs: If a driver uses bd->last to judge when to submit
* requests to hardware, it must define this function. In case of errors
* that make us stop issuing further requests, this hook serves the
* purpose of kicking the hardware (which the last request otherwise
* would have done).
*/
void (*commit_rqs)(struct blk_mq_hw_ctx *);
/**
* @queue_rqs: Queue a list of new requests. Driver is guaranteed
* that each request belongs to the same queue. If the driver doesn't
* empty the @rqlist completely, then the rest will be queued
* individually by the block layer upon return.
*/
void (*queue_rqs)(struct request **rqlist);
/**
* @get_budget: Reserve budget before queue request, once .queue_rq is
* run, it is driver's responsibility to release the
* reserved budget. Also we have to handle failure case
* of .get_budget for avoiding I/O deadlock.
*/
int (*get_budget)(struct request_queue *);
/**
* @put_budget: Release the reserved budget.
*/
void (*put_budget)(struct request_queue *, int);
/**
* @set_rq_budget_token: store rq's budget token
*/
void (*set_rq_budget_token)(struct request *, int);
/**
* @get_rq_budget_token: retrieve rq's budget token
*/
int (*get_rq_budget_token)(struct request *);
/**
* @timeout: Called on request timeout.
*/
enum blk_eh_timer_return (*timeout)(struct request *);
/**
* @poll: Called to poll for completion of a specific tag.
*/
int (*poll)(struct blk_mq_hw_ctx *, struct io_comp_batch *);
/**
* @complete: Mark the request as complete.
*/
void (*complete)(struct request *);
/**
* @init_hctx: Called when the block layer side of a hardware queue has
* been set up, allowing the driver to allocate/init matching
* structures.
*/
int (*init_hctx)(struct blk_mq_hw_ctx *, void *, unsigned int);
/**
* @exit_hctx: Ditto for exit/teardown.
*/
void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int);
/**
* @init_request: Called for every command allocated by the block layer
* to allow the driver to set up driver specific data.
*
* Tag greater than or equal to queue_depth is for setting up
* flush request.
*/
int (*init_request)(struct blk_mq_tag_set *set, struct request *,
unsigned int, unsigned int);
/**
* @exit_request: Ditto for exit/teardown.
*/
void (*exit_request)(struct blk_mq_tag_set *set, struct request *,
unsigned int);
/**
* @cleanup_rq: Called before freeing one request which isn't completed
* yet, and usually for freeing the driver private data.
*/
void (*cleanup_rq)(struct request *);
/**
* @busy: If set, returns whether or not this queue currently is busy.
*/
bool (*busy)(struct request_queue *);
/**
* @map_queues: This allows drivers specify their own queue mapping by
* overriding the setup-time function that builds the mq_map.
*/
void (*map_queues)(struct blk_mq_tag_set *set);
#ifdef CONFIG_BLK_DEBUG_FS
/**
* @show_rq: Used by the debugfs implementation to show driver-specific
* information about a request.
*/
void (*show_rq)(struct seq_file *m, struct request *rq);
#endif
};
/* Keep hctx_flag_name[] in sync with the definitions below */
enum {
BLK_MQ_F_SHOULD_MERGE = 1 << 0,
BLK_MQ_F_TAG_QUEUE_SHARED = 1 << 1,
/*
* Set when this device requires underlying blk-mq device for
* completing IO:
*/
BLK_MQ_F_STACKING = 1 << 2,
BLK_MQ_F_TAG_HCTX_SHARED = 1 << 3,
BLK_MQ_F_BLOCKING = 1 << 4,
/* Do not allow an I/O scheduler to be configured. */
BLK_MQ_F_NO_SCHED = 1 << 5,
/*
* Select 'none' during queue registration in case of a single hwq
* or shared hwqs instead of 'mq-deadline'.
*/
BLK_MQ_F_NO_SCHED_BY_DEFAULT = 1 << 6,
BLK_MQ_F_ALLOC_POLICY_START_BIT = 7,
BLK_MQ_F_ALLOC_POLICY_BITS = 1,
};
#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
((flags >> BLK_MQ_F_ALLOC_POLICY_START_BIT) & \
((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1))
#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
<< BLK_MQ_F_ALLOC_POLICY_START_BIT)
#define BLK_MQ_MAX_DEPTH (10240)
#define BLK_MQ_NO_HCTX_IDX (-1U)
enum {
/* Keep hctx_state_name[] in sync with the definitions below */
BLK_MQ_S_STOPPED,
BLK_MQ_S_TAG_ACTIVE,
BLK_MQ_S_SCHED_RESTART,
/* hw queue is inactive after all its CPUs become offline */
BLK_MQ_S_INACTIVE,
BLK_MQ_S_MAX
};
struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set,
struct queue_limits *lim, void *queuedata,
struct lock_class_key *lkclass);
#define blk_mq_alloc_disk(set, lim, queuedata) \
({ \
static struct lock_class_key __key; \
\
__blk_mq_alloc_disk(set, lim, queuedata, &__key); \
})
struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q,
struct lock_class_key *lkclass);
struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set,
struct queue_limits *lim, void *queuedata);
int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
struct request_queue *q);
void blk_mq_destroy_queue(struct request_queue *);
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set,
const struct blk_mq_ops *ops, unsigned int queue_depth,
unsigned int set_flags);
void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
void blk_mq_free_request(struct request *rq);
int blk_rq_poll(struct request *rq, struct io_comp_batch *iob,
unsigned int poll_flags);
bool blk_mq_queue_inflight(struct request_queue *q);
enum {
/* return when out of requests */
BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0),
/* allocate from reserved pool */
BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1),
/* set RQF_PM */
BLK_MQ_REQ_PM = (__force blk_mq_req_flags_t)(1 << 2),
};
struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf,
blk_mq_req_flags_t flags);
struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
blk_opf_t opf, blk_mq_req_flags_t flags,
unsigned int hctx_idx);
/*
* Tag address space map.
*/
struct blk_mq_tags {
unsigned int nr_tags;
unsigned int nr_reserved_tags;
unsigned int active_queues;
struct sbitmap_queue bitmap_tags;
struct sbitmap_queue breserved_tags;
struct request **rqs;
struct request **static_rqs;
struct list_head page_list;
/*
* used to clear request reference in rqs[] before freeing one
* request pool
*/
spinlock_t lock;
};
static inline struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags,
unsigned int tag)
{
if (tag < tags->nr_tags) {
prefetch(tags->rqs[tag]);
return tags->rqs[tag];
}
return NULL;
}
enum {
BLK_MQ_UNIQUE_TAG_BITS = 16,
BLK_MQ_UNIQUE_TAG_MASK = (1 << BLK_MQ_UNIQUE_TAG_BITS) - 1,
};
u32 blk_mq_unique_tag(struct request *rq);
static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
{
return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
}
static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
{
return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
}
/**
* blk_mq_rq_state() - read the current MQ_RQ_* state of a request
* @rq: target request.
*/
static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
{
return READ_ONCE(rq->state);
}
static inline int blk_mq_request_started(struct request *rq)
{
return blk_mq_rq_state(rq) != MQ_RQ_IDLE;
}
static inline int blk_mq_request_completed(struct request *rq)
{
return blk_mq_rq_state(rq) == MQ_RQ_COMPLETE;
}
/*
*
* Set the state to complete when completing a request from inside ->queue_rq.
* This is used by drivers that want to ensure special complete actions that
* need access to the request are called on failure, e.g. by nvme for
* multipathing.
*/
static inline void blk_mq_set_request_complete(struct request *rq)
{
WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
}
/*
* Complete the request directly instead of deferring it to softirq or
* completing it another CPU. Useful in preemptible instead of an interrupt.
*/
static inline void blk_mq_complete_request_direct(struct request *rq,
void (*complete)(struct request *rq))
{
WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
complete(rq);
}
void blk_mq_start_request(struct request *rq);
void blk_mq_end_request(struct request *rq, blk_status_t error);
void __blk_mq_end_request(struct request *rq, blk_status_t error);
void blk_mq_end_request_batch(struct io_comp_batch *ib);
/*
* Only need start/end time stamping if we have iostat or
* blk stats enabled, or using an IO scheduler.
*/
static inline bool blk_mq_need_time_stamp(struct request *rq)
{
/*
* passthrough io doesn't use iostat accounting, cgroup stats
* and io scheduler functionalities.
*/
if (blk_rq_is_passthrough(rq))
return false;
return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_USE_SCHED));
}
static inline bool blk_mq_is_reserved_rq(struct request *rq)
{
return rq->rq_flags & RQF_RESV;
}
/*
* Batched completions only work when there is no I/O error and no special
* ->end_io handler.
*/
static inline bool blk_mq_add_to_batch(struct request *req,
struct io_comp_batch *iob, int ioerror,
void (*complete)(struct io_comp_batch *))
{
/*
* blk_mq_end_request_batch() can't end request allocated from
* sched tags
*/
if (!iob || (req->rq_flags & RQF_SCHED_TAGS) || ioerror ||
(req->end_io && !blk_rq_is_passthrough(req)))
return false;
if (!iob->complete)
iob->complete = complete;
else if (iob->complete != complete)
return false;
iob->need_ts |= blk_mq_need_time_stamp(req);
rq_list_add(&iob->req_list, req);
return true;
}
void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
void blk_mq_kick_requeue_list(struct request_queue *q);
void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
void blk_mq_complete_request(struct request *rq);
bool blk_mq_complete_request_remote(struct request *rq);
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
void blk_mq_stop_hw_queues(struct request_queue *q);
void blk_mq_start_hw_queues(struct request_queue *q);
void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
void blk_mq_quiesce_queue(struct request_queue *q);
void blk_mq_wait_quiesce_done(struct blk_mq_tag_set *set);
void blk_mq_quiesce_tagset(struct blk_mq_tag_set *set);
void blk_mq_unquiesce_tagset(struct blk_mq_tag_set *set);
void blk_mq_unquiesce_queue(struct request_queue *q);
void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_run_hw_queues(struct request_queue *q, bool async);
void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs);
void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
busy_tag_iter_fn *fn, void *priv);
void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset);
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_unfreeze_queue(struct request_queue *q);
void blk_freeze_queue_start(struct request_queue *q);
void blk_mq_freeze_queue_wait(struct request_queue *q);
int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
unsigned long timeout);
void blk_mq_map_queues(struct blk_mq_queue_map *qmap);
void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
void blk_mq_quiesce_queue_nowait(struct request_queue *q);
unsigned int blk_mq_rq_cpu(struct request *rq);
bool __blk_should_fake_timeout(struct request_queue *q);
static inline bool blk_should_fake_timeout(struct request_queue *q)
{
if (IS_ENABLED(CONFIG_FAIL_IO_TIMEOUT) &&
test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))
return __blk_should_fake_timeout(q);
return false;
}
/**
* blk_mq_rq_from_pdu - cast a PDU to a request
* @pdu: the PDU (Protocol Data Unit) to be casted
*
* Return: request
*
* Driver command data is immediately after the request. So subtract request
* size to get back to the original request.
*/
static inline struct request *blk_mq_rq_from_pdu(void *pdu)
{
return pdu - sizeof(struct request);
}
/**
* blk_mq_rq_to_pdu - cast a request to a PDU
* @rq: the request to be casted
*
* Return: pointer to the PDU
*
* Driver command data is immediately after the request. So add request to get
* the PDU.
*/
static inline void *blk_mq_rq_to_pdu(struct request *rq)
{
return rq + 1;
}
#define queue_for_each_hw_ctx(q, hctx, i) \
xa_for_each(&(q)->hctx_table, (i), (hctx))
#define hctx_for_each_ctx(hctx, ctx, i) \
for ((i) = 0; (i) < (hctx)->nr_ctx && \
({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
static inline void blk_mq_cleanup_rq(struct request *rq)
{
if (rq->q->mq_ops->cleanup_rq)
rq->q->mq_ops->cleanup_rq(rq);
}
static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
unsigned int nr_segs)
{
rq->nr_phys_segments = nr_segs;
rq->__data_len = bio->bi_iter.bi_size;
rq->bio = rq->biotail = bio;
rq->ioprio = bio_prio(bio);
}
void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx,
struct lock_class_key *key);
static inline bool rq_is_sync(struct request *rq)
{
return op_is_sync(rq->cmd_flags);
}
void blk_rq_init(struct request_queue *q, struct request *rq);
int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
struct bio_set *bs, gfp_t gfp_mask,
int (*bio_ctr)(struct bio *, struct bio *, void *), void *data);
void blk_rq_unprep_clone(struct request *rq);
blk_status_t blk_insert_cloned_request(struct request *rq);
struct rq_map_data {
struct page **pages;
unsigned long offset;
unsigned short page_order;
unsigned short nr_entries;
bool null_mapped;
bool from_user;
};
int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long, gfp_t);
int blk_rq_map_user_io(struct request *, struct rq_map_data *,
void __user *, unsigned long, gfp_t, bool, int, bool, int);
int blk_rq_map_user_iov(struct request_queue *, struct request *,
struct rq_map_data *, const struct iov_iter *, gfp_t);
int blk_rq_unmap_user(struct bio *);
int blk_rq_map_kern(struct request_queue *, struct request *, void *,
unsigned int, gfp_t);
int blk_rq_append_bio(struct request *rq, struct bio *bio);
void blk_execute_rq_nowait(struct request *rq, bool at_head);
blk_status_t blk_execute_rq(struct request *rq, bool at_head);
bool blk_rq_is_poll(struct request *rq);
struct req_iterator {
struct bvec_iter iter;
struct bio *bio;
};
#define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
#define rq_for_each_segment(bvl, _rq, _iter) \
__rq_for_each_bio(_iter.bio, _rq) \
bio_for_each_segment(bvl, _iter.bio, _iter.iter)
#define rq_for_each_bvec(bvl, _rq, _iter) \
__rq_for_each_bio(_iter.bio, _rq) \
bio_for_each_bvec(bvl, _iter.bio, _iter.iter)
#define rq_iter_last(bvec, _iter) \
(_iter.bio->bi_next == NULL && \
bio_iter_last(bvec, _iter.iter))
/*
* blk_rq_pos() : the current sector
* blk_rq_bytes() : bytes left in the entire request
* blk_rq_cur_bytes() : bytes left in the current segment
* blk_rq_sectors() : sectors left in the entire request
* blk_rq_cur_sectors() : sectors left in the current segment
* blk_rq_stats_sectors() : sectors of the entire request used for stats
*/
static inline sector_t blk_rq_pos(const struct request *rq)
{
return rq->__sector;
}
static inline unsigned int blk_rq_bytes(const struct request *rq)
{
return rq->__data_len;
}
static inline int blk_rq_cur_bytes(const struct request *rq)
{
if (!rq->bio)
return 0;
if (!bio_has_data(rq->bio)) /* dataless requests such as discard */
return rq->bio->bi_iter.bi_size;
return bio_iovec(rq->bio).bv_len;
}
static inline unsigned int blk_rq_sectors(const struct request *rq)
{
return blk_rq_bytes(rq) >> SECTOR_SHIFT;
}
static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
{
return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
}
static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
{
return rq->stats_sectors;
}
/*
* Some commands like WRITE SAME have a payload or data transfer size which
* is different from the size of the request. Any driver that supports such
* commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
* calculate the data transfer size.
*/
static inline unsigned int blk_rq_payload_bytes(struct request *rq)
{
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
return rq->special_vec.bv_len;
return blk_rq_bytes(rq);
}
/*
* Return the first full biovec in the request. The caller needs to check that
* there are any bvecs before calling this helper.
*/
static inline struct bio_vec req_bvec(struct request *rq)
{
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
return rq->special_vec;
return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
}
static inline unsigned int blk_rq_count_bios(struct request *rq)
{
unsigned int nr_bios = 0;
struct bio *bio;
__rq_for_each_bio(bio, rq)
nr_bios++;
return nr_bios;
}
void blk_steal_bios(struct bio_list *list, struct request *rq);
/*
* Request completion related functions.
*
* blk_update_request() completes given number of bytes and updates
* the request without completing it.
*/
bool blk_update_request(struct request *rq, blk_status_t error,
unsigned int nr_bytes);
void blk_abort_request(struct request *);
/*
* Number of physical segments as sent to the device.
*
* Normally this is the number of discontiguous data segments sent by the
* submitter. But for data-less command like discard we might have no
* actual data segments submitted, but the driver might have to add it's
* own special payload. In that case we still return 1 here so that this
* special payload will be mapped.
*/
static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
{
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
return 1;
return rq->nr_phys_segments;
}
/*
* Number of discard segments (or ranges) the driver needs to fill in.
* Each discard bio merged into a request is counted as one segment.
*/
static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
{
return max_t(unsigned short, rq->nr_phys_segments, 1);
}
int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sglist, struct scatterlist **last_sg);
static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sglist)
{
struct scatterlist *last_sg = NULL;
return __blk_rq_map_sg(q, rq, sglist, &last_sg);
}
void blk_dump_rq_flags(struct request *, char *);
#endif /* BLK_MQ_H */
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