// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/dax.h>

#include "pcache_internal.h"
#include "cache_dev.h"
#include "segment.h"

int segment_copy_to_bio(struct pcache_segment *segment,
                u32 data_off, u32 data_len, struct bio *bio, u32 bio_off)
{
        struct iov_iter iter;
        size_t copied;
        void *src;

        iov_iter_bvec(&iter, ITER_DEST, &bio->bi_io_vec[bio->bi_iter.bi_idx],
                        bio_segments(bio), bio->bi_iter.bi_size);
        iter.iov_offset = bio->bi_iter.bi_bvec_done;
        if (bio_off)
                iov_iter_advance(&iter, bio_off);

        src = segment->data + data_off;
        copied = _copy_mc_to_iter(src, data_len, &iter);
        if (copied != data_len)
                return -EIO;

        return 0;
}

int segment_copy_from_bio(struct pcache_segment *segment,
                u32 data_off, u32 data_len, struct bio *bio, u32 bio_off)
{
        struct iov_iter iter;
        size_t copied;
        void *dst;

        iov_iter_bvec(&iter, ITER_SOURCE, &bio->bi_io_vec[bio->bi_iter.bi_idx],
                        bio_segments(bio), bio->bi_iter.bi_size);
        iter.iov_offset = bio->bi_iter.bi_bvec_done;
        if (bio_off)
                iov_iter_advance(&iter, bio_off);

        dst = segment->data + data_off;
        copied = _copy_from_iter_flushcache(dst, data_len, &iter);
        if (copied != data_len)
                return -EIO;
        pmem_wmb();

        return 0;
}

void pcache_segment_init(struct pcache_cache_dev *cache_dev, struct pcache_segment *segment,
                      struct pcache_segment_init_options *options)
{
        segment->seg_info = options->seg_info;
        segment_info_set_type(segment->seg_info, options->type);

        segment->cache_dev = cache_dev;
        segment->seg_id = options->seg_id;
        segment->data_size = PCACHE_SEG_SIZE - options->data_off;
        segment->data = CACHE_DEV_SEGMENT(cache_dev, options->seg_id) + options->data_off;
}