/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H

#include <linux/blk-crypto.h>
#include <linux/memblock.h>     /* for max_pfn/max_low_pfn */
#include <xen/xen.h>
#include "blk-crypto-internal.h"

struct elevator_type;

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

extern struct dentry *blk_debugfs_root;

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

        spinlock_t              mq_flush_lock;
};

extern struct kmem_cache *blk_requestq_cachep;
extern struct kmem_cache *blk_requestq_srcu_cachep;
extern struct kobj_type blk_queue_ktype;
extern struct ida blk_queue_ida;

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

bool is_flush_rq(struct request *req);

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

void blk_freeze_queue(struct request_queue *q);
void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
void blk_queue_start_drain(struct request_queue *q);
int __bio_queue_enter(struct request_queue *q, struct bio *bio);
void submit_bio_noacct_nocheck(struct bio *bio);

static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
{
        rcu_read_lock();
        if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
                goto fail;

        /*
         * The code that increments the pm_only counter must ensure that the
         * counter is globally visible before the queue is unfrozen.
         */
        if (blk_queue_pm_only(q) &&
            (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
                goto fail_put;

        rcu_read_unlock();
        return true;

fail_put:
        blk_queue_exit(q);
fail:
        rcu_read_unlock();
        return false;
}

static inline int bio_queue_enter(struct bio *bio)
{
        struct request_queue *q = bdev_get_queue(bio->bi_bdev);

        if (blk_try_enter_queue(q, false))
                return 0;
        return __bio_queue_enter(q, bio);
}

#define BIO_INLINE_VECS 4
struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
                gfp_t gfp_mask);
void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);

static inline bool biovec_phys_mergeable(struct request_queue *q,
                struct bio_vec *vec1, struct bio_vec *vec2)
{
        unsigned long mask = queue_segment_boundary(q);
        phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
        phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;

        if (addr1 + vec1->bv_len != addr2)
                return false;
        if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
                return false;
        if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
                return false;
        return true;
}

static inline bool __bvec_gap_to_prev(struct request_queue *q,
                struct bio_vec *bprv, unsigned int offset)
{
        return (offset & queue_virt_boundary(q)) ||
                ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
}

/*
 * Check if adding a bio_vec after bprv with offset would create a gap in
 * the SG list. Most drivers don't care about this, but some do.
 */
static inline bool bvec_gap_to_prev(struct request_queue *q,
                struct bio_vec *bprv, unsigned int offset)
{
        if (!queue_virt_boundary(q))
                return false;
        return __bvec_gap_to_prev(q, bprv, offset);
}

static inline bool rq_mergeable(struct request *rq)
{
        if (blk_rq_is_passthrough(rq))
                return false;

        if (req_op(rq) == REQ_OP_FLUSH)
                return false;

        if (req_op(rq) == REQ_OP_WRITE_ZEROES)
                return false;

        if (req_op(rq) == REQ_OP_ZONE_APPEND)
                return false;

        if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
                return false;
        if (rq->rq_flags & RQF_NOMERGE_FLAGS)
                return false;

        return true;
}

/*
 * There are two different ways to handle DISCARD merges:
 *  1) If max_discard_segments > 1, the driver treats every bio as a range and
 *     send the bios to controller together. The ranges don't need to be
 *     contiguous.
 *  2) Otherwise, the request will be normal read/write requests.  The ranges
 *     need to be contiguous.
 */
static inline bool blk_discard_mergable(struct request *req)
{
        if (req_op(req) == REQ_OP_DISCARD &&
            queue_max_discard_segments(req->q) > 1)
                return true;
        return false;
}

#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_flush_integrity(void);
bool __bio_integrity_endio(struct bio *);
void bio_integrity_free(struct bio *bio);
static inline bool bio_integrity_endio(struct bio *bio)
{
        if (bio_integrity(bio))
                return __bio_integrity_endio(bio);
        return true;
}

bool blk_integrity_merge_rq(struct request_queue *, struct request *,
                struct request *);
bool blk_integrity_merge_bio(struct request_queue *, struct request *,
                struct bio *);

static inline bool integrity_req_gap_back_merge(struct request *req,
                struct bio *next)
{
        struct bio_integrity_payload *bip = bio_integrity(req->bio);
        struct bio_integrity_payload *bip_next = bio_integrity(next);

        return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
                                bip_next->bip_vec[0].bv_offset);
}

static inline bool integrity_req_gap_front_merge(struct request *req,
                struct bio *bio)
{
        struct bio_integrity_payload *bip = bio_integrity(bio);
        struct bio_integrity_payload *bip_next = bio_integrity(req->bio);

        return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
                                bip_next->bip_vec[0].bv_offset);
}

int blk_integrity_add(struct gendisk *disk);
void blk_integrity_del(struct gendisk *);
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline bool blk_integrity_merge_rq(struct request_queue *rq,
                struct request *r1, struct request *r2)
{
        return true;
}
static inline bool blk_integrity_merge_bio(struct request_queue *rq,
                struct request *r, struct bio *b)
{
        return true;
}
static inline bool integrity_req_gap_back_merge(struct request *req,
                struct bio *next)
{
        return false;
}
static inline bool integrity_req_gap_front_merge(struct request *req,
                struct bio *bio)
{
        return false;
}

static inline void blk_flush_integrity(void)
{
}
static inline bool bio_integrity_endio(struct bio *bio)
{
        return true;
}
static inline void bio_integrity_free(struct bio *bio)
{
}
static inline int blk_integrity_add(struct gendisk *disk)
{
        return 0;
}
static inline void blk_integrity_del(struct gendisk *disk)
{
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */

unsigned long blk_rq_timeout(unsigned long timeout);
void blk_add_timer(struct request *req);
const char *blk_status_to_str(blk_status_t status);

bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
                unsigned int nr_segs);
bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
                        struct bio *bio, unsigned int nr_segs);

/*
 * Plug flush limits
 */
#define BLK_MAX_REQUEST_COUNT   32
#define BLK_PLUG_FLUSH_SIZE     (128 * 1024)

/*
 * Internal elevator interface
 */
#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)

void blk_insert_flush(struct request *rq);

int elevator_switch_mq(struct request_queue *q,
                              struct elevator_type *new_e);
void elevator_exit(struct request_queue *q);
int elv_register_queue(struct request_queue *q, bool uevent);
void elv_unregister_queue(struct request_queue *q);

ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
                char *buf);
ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
                char *buf);
ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
                char *buf);
ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
                char *buf);
ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
                const char *buf, size_t count);
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);

static inline bool blk_may_split(struct request_queue *q, struct bio *bio)
{
        switch (bio_op(bio)) {
        case REQ_OP_DISCARD:
        case REQ_OP_SECURE_ERASE:
        case REQ_OP_WRITE_ZEROES:
                return true; /* non-trivial splitting decisions */
        default:
                break;
        }

        /*
         * All drivers must accept single-segments bios that are <= PAGE_SIZE.
         * This is a quick and dirty check that relies on the fact that
         * bi_io_vec[0] is always valid if a bio has data.  The check might
         * lead to occasional false negatives when bios are cloned, but compared
         * to the performance impact of cloned bios themselves the loop below
         * doesn't matter anyway.
         */
        return q->limits.chunk_sectors || bio->bi_vcnt != 1 ||
                bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
}

void __blk_queue_split(struct request_queue *q, struct bio **bio,
                        unsigned int *nr_segs);
int ll_back_merge_fn(struct request *req, struct bio *bio,
                unsigned int nr_segs);
bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
                                struct request *next);
unsigned int 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);

int blk_dev_init(void);

/*
 * 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
 */
static inline bool blk_do_io_stat(struct request *rq)
{
        return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
}

void update_io_ticks(struct block_device *part, unsigned long now, bool end);

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;
}

/*
 * 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;
}

/*
 * The max bio size which is aligned to q->limits.discard_granularity. This
 * is a hint to split large discard bio in generic block layer, then if device
 * driver needs to split the discard bio into smaller ones, their bi_size can
 * be very probably and easily aligned to discard_granularity of the device's
 * queue.
 */
static inline unsigned int bio_aligned_discard_max_sectors(
                                        struct request_queue *q)
{
        return round_down(UINT_MAX, q->limits.discard_granularity) >>
                        SECTOR_SHIFT;
}

/*
 * Internal io_context interface
 */
struct io_cq *ioc_find_get_icq(struct request_queue *q);
struct io_cq *ioc_lookup_icq(struct request_queue *q);
#ifdef CONFIG_BLK_ICQ
void ioc_clear_queue(struct request_queue *q);
#else
static inline void ioc_clear_queue(struct request_queue *q)
{
}
#endif /* CONFIG_BLK_ICQ */

#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

void __blk_queue_bounce(struct request_queue *q, struct bio **bio);

static inline bool blk_queue_may_bounce(struct request_queue *q)
{
        return IS_ENABLED(CONFIG_BOUNCE) &&
                q->limits.bounce == BLK_BOUNCE_HIGH &&
                max_low_pfn >= max_pfn;
}

static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
{
        if (unlikely(blk_queue_may_bounce(q) && bio_has_data(*bio)))
                __blk_queue_bounce(q, bio);     
}

#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

#ifdef CONFIG_BLK_DEV_ZONED
void blk_queue_free_zone_bitmaps(struct request_queue *q);
void blk_queue_clear_zone_settings(struct request_queue *q);
#else
static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
static inline void blk_queue_clear_zone_settings(struct request_queue *q) {}
#endif

int blk_alloc_ext_minor(void);
void blk_free_ext_minor(unsigned int minor);
#define ADDPART_FLAG_NONE       0
#define ADDPART_FLAG_RAID       1
#define ADDPART_FLAG_WHOLEDISK  2
int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
                sector_t length);
int bdev_del_partition(struct gendisk *disk, int partno);
int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
                sector_t length);
void blk_drop_partitions(struct gendisk *disk);

int bio_add_hw_page(struct request_queue *q, struct bio *bio,
                struct page *page, unsigned int len, unsigned int offset,
                unsigned int max_sectors, bool *same_page);

static inline struct kmem_cache *blk_get_queue_kmem_cache(bool srcu)
{
        if (srcu)
                return blk_requestq_srcu_cachep;
        return blk_requestq_cachep;
}
struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu);

int disk_scan_partitions(struct gendisk *disk, fmode_t mode);

int disk_alloc_events(struct gendisk *disk);
void disk_add_events(struct gendisk *disk);
void disk_del_events(struct gendisk *disk);
void disk_release_events(struct gendisk *disk);
void disk_block_events(struct gendisk *disk);
void disk_unblock_events(struct gendisk *disk);
void disk_flush_events(struct gendisk *disk, unsigned int mask);
extern struct device_attribute dev_attr_events;
extern struct device_attribute dev_attr_events_async;
extern struct device_attribute dev_attr_events_poll_msecs;

static inline void bio_clear_polled(struct bio *bio)
{
        /* can't support alloc cache if we turn off polling */
        bio_clear_flag(bio, BIO_PERCPU_CACHE);
        bio->bi_opf &= ~REQ_POLLED;
}

long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);

extern const struct address_space_operations def_blk_aops;

int disk_register_independent_access_ranges(struct gendisk *disk,
                                struct blk_independent_access_ranges *new_iars);
void disk_unregister_independent_access_ranges(struct gendisk *disk);

#ifdef CONFIG_FAIL_MAKE_REQUEST
bool should_fail_request(struct block_device *part, unsigned int bytes);
#else /* CONFIG_FAIL_MAKE_REQUEST */
static inline bool should_fail_request(struct block_device *part,
                                        unsigned int bytes)
{
        return false;
}
#endif /* CONFIG_FAIL_MAKE_REQUEST */

/*
 * Optimized request reference counting. Ideally we'd make timeouts be more
 * clever, as that's the only reason we need references at all... But until
 * this happens, this is faster than using refcount_t. Also see:
 *
 * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
 */
#define req_ref_zero_or_close_to_overflow(req)  \
        ((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)

static inline bool req_ref_inc_not_zero(struct request *req)
{
        return atomic_inc_not_zero(&req->ref);
}

static inline bool req_ref_put_and_test(struct request *req)
{
        WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
        return atomic_dec_and_test(&req->ref);
}

static inline void req_ref_set(struct request *req, int value)
{
        atomic_set(&req->ref, value);
}

static inline int req_ref_read(struct request *req)
{
        return atomic_read(&req->ref);
}

#endif /* BLK_INTERNAL_H */