linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Functions related to mapping data to requests

 */

#include <linux/kernel.h>

#include <linux/sched/task_stack.h>

#include <linux/module.h>

#include <linux/bio.h>

#include <linux/blkdev.h>

#include <linux/uio.h>

​

#include "blk.h"

​

/*

 * Append a bio to a passthrough request.  Only works if the bio can be merged

 * into the request based on the driver constraints.

 */

int blk_rq_append_bio(struct request *rq, struct bio **bio)

{

    struct bio *orig_bio = *bio;

​

    blk_queue_bounce(rq->q, bio);

​

    if (!rq->bio) {

        blk_rq_bio_prep(rq->q, rq, *bio);

    } else {

        if (!ll_back_merge_fn(rq->q, rq, *bio)) {

            if (orig_bio != *bio) {

                bio_put(*bio);

                *bio = orig_bio;

            }

            return -EINVAL;

        }

​

        rq->biotail->bi_next = *bio;

        rq->biotail = *bio;

        rq->__data_len += (*bio)->bi_iter.bi_size;

    }

​

    return 0;

}

EXPORT_SYMBOL(blk_rq_append_bio);

​

static int __blk_rq_unmap_user(struct bio *bio)

{

    int ret = 0;

​

    if (bio) {

        if (bio_flagged(bio, BIO_USER_MAPPED))

            bio_unmap_user(bio);

        else

            ret = bio_uncopy_user(bio);

    }

​

    return ret;

}

​

static int __blk_rq_map_user_iov(struct request *rq,

        struct rq_map_data *map_data, struct iov_iter *iter,

        gfp_t gfp_mask, bool copy)

{

    struct request_queue *q = rq->q;

    struct bio *bio, *orig_bio;