linux-imx

/*

 * Zoned block device handling

 *

 * Copyright (c) 2015, Hannes Reinecke

 * Copyright (c) 2015, SUSE Linux GmbH

 *

 * Copyright (c) 2016, Damien Le Moal

 * Copyright (c) 2016, Western Digital

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/rbtree.h>

#include <linux/blkdev.h>

#include <linux/blk-mq.h>

​

#include "blk.h"

​

static inline sector_t blk_zone_start(struct request_queue *q,

                      sector_t sector)

{

    sector_t zone_mask = blk_queue_zone_sectors(q) - 1;

​

    return sector & ~zone_mask;

}

​

/*

 * Return true if a request is a write requests that needs zone write locking.

 */

bool blk_req_needs_zone_write_lock(struct request *rq)

{

    if (!rq->q->seq_zones_wlock)

        return false;

​

    if (blk_rq_is_passthrough(rq))

        return false;

​

    switch (req_op(rq)) {

    case REQ_OP_WRITE_ZEROES:

    case REQ_OP_WRITE_SAME:

    case REQ_OP_WRITE:

        return blk_rq_zone_is_seq(rq);

    default:

        return false;

    }

}

EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);

​

void __blk_req_zone_write_lock(struct request *rq)

{

    if (WARN_ON_ONCE(test_and_set_bit(blk_rq_zone_no(rq),

                      rq->q->seq_zones_wlock)))

        return;

​

    WARN_ON_ONCE(rq->rq_flags & RQF_ZONE_WRITE_LOCKED);

    rq->rq_flags |= RQF_ZONE_WRITE_LOCKED;

}

EXPORT_SYMBOL_GPL(__blk_req_zone_write_lock);

​

void __blk_req_zone_write_unlock(struct request *rq)

{

    rq->rq_flags &= ~RQF_ZONE_WRITE_LOCKED;

    if (rq->q->seq_zones_wlock)

        WARN_ON_ONCE(!test_and_clear_bit(blk_rq_zone_no(rq),

                         rq->q->seq_zones_wlock));

}

EXPORT_SYMBOL_GPL(__blk_req_zone_write_unlock);

​

static inline unsigned int __blkdev_nr_zones(struct request_queue *q,

                         sector_t nr_sectors)

{

    unsigned long zone_sectors = blk_queue_zone_sectors(q);

​

    return (nr_sectors + zone_sectors - 1) >> ilog2(zone_sectors);

}

​

/**

 * blkdev_nr_zones - Get number of zones

 * @bdev:   Target block device

 *

 * Description:

 *    Return the total number of zones of a zoned block device.

 *    For a regular block device, the number of zones is always 0.

 */

unsigned int blkdev_nr_zones(struct block_device *bdev)

{

    struct request_queue *q = bdev_get_queue(bdev);

​

    if (!blk_queue_is_zoned(q))

        return 0;

​

    return __blkdev_nr_zones(q, bdev->bd_part->nr_sects);