// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
 * Copyright (c) Thomas Gleixner <tglx@linutronix.de>
 *
 * The parts taken from the kernel implementation are:
 *
 * Copyright (c) International Business Machines Corp., 2006
 */

#include <common.h>
#include <errno.h>
#include <u-boot/crc.h>
#include <ubispl.h>

#include <linux/crc32.h>

#include "ubispl.h"

/**
 * ubi_calc_fm_size - calculates the fastmap size in bytes for an UBI device.
 * @ubi: UBI device description object
 */
static size_t ubi_calc_fm_size(struct ubi_scan_info *ubi)
{
        size_t size;

        size = sizeof(struct ubi_fm_sb) +
                sizeof(struct ubi_fm_hdr) +
                sizeof(struct ubi_fm_scan_pool) +
                sizeof(struct ubi_fm_scan_pool) +
                (ubi->peb_count * sizeof(struct ubi_fm_ec)) +
                (sizeof(struct ubi_fm_eba) +
                (ubi->peb_count * sizeof(__be32))) +
                sizeof(struct ubi_fm_volhdr) * UBI_MAX_VOLUMES;
        return roundup(size, ubi->leb_size);
}

static int ubi_io_read(struct ubi_scan_info *ubi, void *buf, int pnum,
                       unsigned long from, unsigned long len)
{
        return ubi->read(pnum + ubi->peb_offset, from, len, buf);
}

static int ubi_io_is_bad(struct ubi_scan_info *ubi, int peb)
{
        return peb >= ubi->peb_count || peb < 0;
}

#ifdef CONFIG_SPL_UBI_LOAD_BY_VOLNAME

/**
 * ubi_dump_vtbl_record - dump a &struct ubi_vtbl_record object.
 * @r: the object to dump
 * @idx: volume table index
 */
void ubi_dump_vtbl_record(const struct ubi_vtbl_record *r, int idx)
{
        int name_len = be16_to_cpu(r->name_len);

        ubi_dbg("Volume table record %d dump: size: %d",
                idx, sizeof(struct ubi_vtbl_record));
        ubi_dbg("\treserved_pebs   %d", be32_to_cpu(r->reserved_pebs));
        ubi_dbg("\talignment       %d", be32_to_cpu(r->alignment));
        ubi_dbg("\tdata_pad        %d", be32_to_cpu(r->data_pad));
        ubi_dbg("\tvol_type        %d", (int)r->vol_type);
        ubi_dbg("\tupd_marker      %d", (int)r->upd_marker);
        ubi_dbg("\tname_len        %d", name_len);

        if (r->name[0] == '\0') {
                ubi_dbg("\tname            NULL");
                return;
        }

        if (name_len <= UBI_VOL_NAME_MAX &&
            strnlen(&r->name[0], name_len + 1) == name_len) {
                ubi_dbg("\tname            %s", &r->name[0]);
        } else {
                ubi_dbg("\t1st 5 characters of name: %c%c%c%c%c",
                        r->name[0], r->name[1], r->name[2], r->name[3],
                        r->name[4]);
        }
        ubi_dbg("\tcrc             %#08x", be32_to_cpu(r->crc));
}

/* Empty volume table record */
static struct ubi_vtbl_record empty_vtbl_record;

/**
 * vtbl_check - check if volume table is not corrupted and sensible.
 * @ubi: UBI device description object
 * @vtbl: volume table
 *
 * This function returns zero if @vtbl is all right, %1 if CRC is incorrect,
 * and %-EINVAL if it contains inconsistent data.
 */
static int vtbl_check(struct ubi_scan_info *ubi,
                      struct ubi_vtbl_record *vtbl)
{
        int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
        int upd_marker, err;
        uint32_t crc;
        const char *name;

        for (i = 0; i < UBI_SPL_VOL_IDS; i++) {
                reserved_pebs = be32_to_cpu(vtbl[i].reserved_pebs);
                alignment = be32_to_cpu(vtbl[i].alignment);
                data_pad = be32_to_cpu(vtbl[i].data_pad);
                upd_marker = vtbl[i].upd_marker;
                vol_type = vtbl[i].vol_type;
                name_len = be16_to_cpu(vtbl[i].name_len);
                name = &vtbl[i].name[0];

                crc = crc32(UBI_CRC32_INIT, &vtbl[i], UBI_VTBL_RECORD_SIZE_CRC);
                if (be32_to_cpu(vtbl[i].crc) != crc) {
                        ubi_err("bad CRC at record %u: %#08x, not %#08x",
                                i, crc, be32_to_cpu(vtbl[i].crc));
                        ubi_dump_vtbl_record(&vtbl[i], i);
                        return 1;
                }

                if (reserved_pebs == 0) {
                        if (memcmp(&vtbl[i], &empty_vtbl_record,
                                   UBI_VTBL_RECORD_SIZE)) {
                                err = 2;
                                goto bad;
                        }
                        continue;
                }

                if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
                    name_len < 0) {
                        err = 3;
                        goto bad;
                }

                if (alignment > ubi->leb_size || alignment == 0) {
                        err = 4;
                        goto bad;
                }

                n = alignment & (CONFIG_SPL_UBI_VID_OFFSET - 1);
                if (alignment != 1 && n) {
                        err = 5;
                        goto bad;
                }

                n = ubi->leb_size % alignment;
                if (data_pad != n) {
                        ubi_err("bad data_pad, has to be %d", n);
                        err = 6;
                        goto bad;
                }

                if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
                        err = 7;
                        goto bad;
                }

                if (upd_marker != 0 && upd_marker != 1) {
                        err = 8;
                        goto bad;
                }

                if (name_len > UBI_VOL_NAME_MAX) {
                        err = 10;
                        goto bad;
                }

                if (name[0] == '\0') {
                        err = 11;
                        goto bad;
                }

                if (name_len != strnlen(name, name_len + 1)) {
                        err = 12;
                        goto bad;
                }

                ubi_dump_vtbl_record(&vtbl[i], i);
        }

        /* Checks that all names are unique */
        for (i = 0; i < UBI_SPL_VOL_IDS - 1; i++) {
                for (n = i + 1; n < UBI_SPL_VOL_IDS; n++) {
                        int len1 = be16_to_cpu(vtbl[i].name_len);
                        int len2 = be16_to_cpu(vtbl[n].name_len);

                        if (len1 > 0 && len1 == len2 &&
                            !strncmp(vtbl[i].name, vtbl[n].name, len1)) {
                                ubi_err("volumes %d and %d have the same name \"%s\"",
                                        i, n, vtbl[i].name);
                                ubi_dump_vtbl_record(&vtbl[i], i);
                                ubi_dump_vtbl_record(&vtbl[n], n);
                                return -EINVAL;
                        }
                }
        }

        return 0;

bad:
        ubi_err("volume table check failed: record %d, error %d", i, err);
        ubi_dump_vtbl_record(&vtbl[i], i);
        return -EINVAL;
}

static int ubi_read_volume_table(struct ubi_scan_info *ubi, u32 pnum)
{
        int err = -EINVAL;

        empty_vtbl_record.crc = cpu_to_be32(0xf116c36b);

        err = ubi_io_read(ubi, &ubi->vtbl, pnum, ubi->leb_start,
                          sizeof(struct ubi_vtbl_record) * UBI_SPL_VOL_IDS);
        if (err && err != UBI_IO_BITFLIPS) {
                ubi_err("unable to read volume table");
                goto out;
        }

        if (!vtbl_check(ubi, ubi->vtbl)) {
                ubi->vtbl_valid = 1;
                err = 0;
        }
out:
        return err;
}

#endif /* CONFIG_SPL_UBI_LOAD_BY_VOLNAME */

static int ubi_io_read_vid_hdr(struct ubi_scan_info *ubi, int pnum,
                               struct ubi_vid_hdr *vh, int unused)
{
        u32 magic;
        int res;

        /* No point in rescanning a corrupt block */
        if (test_bit(pnum, ubi->corrupt))
                return UBI_IO_BAD_HDR;
        /*
         * If the block has been scanned already, no need to rescan
         */
        if (test_and_set_bit(pnum, ubi->scanned))
                return 0;

        res = ubi_io_read(ubi, vh, pnum, ubi->vid_offset, sizeof(*vh));

        /*
         * Bad block, unrecoverable ECC error, skip the block
         */
        if (res) {
                ubi_dbg("Skipping bad or unreadable block %d", pnum);
                vh->magic = 0;
                generic_set_bit(pnum, ubi->corrupt);
                return res;
        }

        /* Magic number available ? */
        magic = be32_to_cpu(vh->magic);
        if (magic != UBI_VID_HDR_MAGIC) {
                generic_set_bit(pnum, ubi->corrupt);
                if (magic == 0xffffffff)
                        return UBI_IO_FF;
                ubi_msg("Bad magic in block 0%d %08x", pnum, magic);
                return UBI_IO_BAD_HDR;
        }

        /* Header CRC correct ? */
        if (crc32(UBI_CRC32_INIT, vh, UBI_VID_HDR_SIZE_CRC) !=
            be32_to_cpu(vh->hdr_crc)) {
                ubi_msg("Bad CRC in block 0%d", pnum);
                generic_set_bit(pnum, ubi->corrupt);
                return UBI_IO_BAD_HDR;
        }

        ubi_dbg("RV: pnum: %i sqnum %llu", pnum, be64_to_cpu(vh->sqnum));

        return 0;
}

static int ubi_rescan_fm_vid_hdr(struct ubi_scan_info *ubi,
                                 struct ubi_vid_hdr *vh,
                                 u32 fm_pnum, u32 fm_vol_id, u32 fm_lnum)
{
        int res;

        if (ubi_io_is_bad(ubi, fm_pnum))
                return -EINVAL;

        res = ubi_io_read_vid_hdr(ubi, fm_pnum, vh, 0);
        if (!res) {
                /* Check volume id, volume type and lnum */
                if (be32_to_cpu(vh->vol_id) == fm_vol_id &&
                    vh->vol_type == UBI_VID_STATIC &&
                    be32_to_cpu(vh->lnum) == fm_lnum)
                        return 0;
                ubi_dbg("RS: PEB %u vol: %u : %u typ %u lnum %u %u",
                        fm_pnum, fm_vol_id, vh->vol_type,
                        be32_to_cpu(vh->vol_id),
                        fm_lnum, be32_to_cpu(vh->lnum));
        }
        return res;
}

/* Insert the logic block into the volume info */
static int ubi_add_peb_to_vol(struct ubi_scan_info *ubi,
                              struct ubi_vid_hdr *vh, u32 vol_id,
                              u32 pnum, u32 lnum)
{
        struct ubi_vol_info *vi = ubi->volinfo + vol_id;
        u32 *ltp;

        /*
         * If the volume is larger than expected, yell and give up :(
         */
        if (lnum >= UBI_MAX_VOL_LEBS) {
                ubi_warn("Vol: %u LEB %d > %d", vol_id, lnum, UBI_MAX_VOL_LEBS);
                return -EINVAL;
        }

        ubi_dbg("SC: Add PEB %u to Vol %u as LEB %u fnd %d sc %d",
                pnum, vol_id, lnum, !!test_bit(lnum, vi->found),
                !!test_bit(pnum, ubi->scanned));

        /* Points to the translation entry */
        ltp = vi->lebs_to_pebs + lnum;

        /* If the block is already assigned, check sqnum */
        if (__test_and_set_bit(lnum, vi->found)) {
                u32 cur_pnum = *ltp;
                struct ubi_vid_hdr *cur = ubi->blockinfo + cur_pnum;

                /*
                 * If the current block hase not yet been scanned, we
                 * need to do that. The other block might be stale or
                 * the current block corrupted and the FM not yet
                 * updated.
                 */
                if (!test_bit(cur_pnum, ubi->scanned)) {
                        /*
                         * If the scan fails, we use the valid block
                         */
                        if (ubi_rescan_fm_vid_hdr(ubi, cur, cur_pnum, vol_id,
                                                  lnum)) {
                                *ltp = pnum;
                                return 0;
                        }
                }

                /*
                 * Should not happen ....
                 */
                if (test_bit(cur_pnum, ubi->corrupt)) {
                        *ltp = pnum;
                        return 0;
                }

                ubi_dbg("Vol %u LEB %u PEB %u->sqnum %llu NPEB %u->sqnum %llu",
                        vol_id, lnum, cur_pnum, be64_to_cpu(cur->sqnum), pnum,
                        be64_to_cpu(vh->sqnum));

                /*
                 * Compare sqnum and take the newer one
                 */
                if (be64_to_cpu(cur->sqnum) < be64_to_cpu(vh->sqnum))
                        *ltp = pnum;
        } else {
                *ltp = pnum;
                if (lnum > vi->last_block)
                        vi->last_block = lnum;
        }

        return 0;
}

static int ubi_scan_vid_hdr(struct ubi_scan_info *ubi, struct ubi_vid_hdr *vh,
                            u32 pnum)
{
        u32 vol_id, lnum;
        int res;

        if (ubi_io_is_bad(ubi, pnum))
                return -EINVAL;

        res = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
        if (res)
                return res;

        /* Get volume id */
        vol_id = be32_to_cpu(vh->vol_id);

        /* If this is the fastmap anchor, return right away */
        if (vol_id == UBI_FM_SB_VOLUME_ID)
                return ubi->fm_enabled ? UBI_FASTMAP_ANCHOR : 0;

#ifdef CONFIG_SPL_UBI_LOAD_BY_VOLNAME
        /* If this is a UBI volume table, read it and return */
        if (vol_id == UBI_LAYOUT_VOLUME_ID && !ubi->vtbl_valid) {
                res = ubi_read_volume_table(ubi, pnum);
                return res;
        }
#endif

        /* We only care about static volumes with an id < UBI_SPL_VOL_IDS */
        if (vol_id >= UBI_SPL_VOL_IDS || vh->vol_type != UBI_VID_STATIC)
                return 0;

#ifndef CONFIG_SPL_UBI_LOAD_BY_VOLNAME
        /* We are only interested in the volumes to load */
        if (!test_bit(vol_id, ubi->toload))
                return 0;
#endif
        lnum = be32_to_cpu(vh->lnum);
        return ubi_add_peb_to_vol(ubi, vh, vol_id, pnum, lnum);
}

static int assign_aeb_to_av(struct ubi_scan_info *ubi, u32 pnum, u32 lnum,
                             u32 vol_id, u32 vol_type, u32 used)
{
        struct ubi_vid_hdr *vh;

        if (ubi_io_is_bad(ubi, pnum))
                return -EINVAL;

        ubi->fastmap_pebs++;

#ifndef CONFIG_SPL_UBI_LOAD_BY_VOLNAME
        if (vol_id >= UBI_SPL_VOL_IDS || vol_type != UBI_STATIC_VOLUME)
                return 0;

        /* We are only interested in the volumes to load */
        if (!test_bit(vol_id, ubi->toload))
                return 0;
#endif
        vh = ubi->blockinfo + pnum;

        return ubi_scan_vid_hdr(ubi, vh, pnum);
}

static int scan_pool(struct ubi_scan_info *ubi, __be32 *pebs, int pool_size)
{
        struct ubi_vid_hdr *vh;
        u32 pnum;
        int i;

        ubi_dbg("Scanning pool size: %d", pool_size);

        for (i = 0; i < pool_size; i++) {
                pnum = be32_to_cpu(pebs[i]);

                if (ubi_io_is_bad(ubi, pnum)) {
                        ubi_err("FM: Bad PEB in fastmap pool! %u", pnum);
                        return UBI_BAD_FASTMAP;
                }

                vh = ubi->blockinfo + pnum;
                /*
                 * We allow the scan to fail here. The loader will notice
                 * and look for a replacement.
                 */
                ubi_scan_vid_hdr(ubi, vh, pnum);
        }
        return 0;
}

/*
 * Fastmap code is stolen from Linux kernel and this stub structure is used
 * to make it happy.
 */
struct ubi_attach_info {
        int i;
};

static int ubi_attach_fastmap(struct ubi_scan_info *ubi,
                              struct ubi_attach_info *ai,
                              struct ubi_fastmap_layout *fm)
{
        struct ubi_fm_hdr *fmhdr;
        struct ubi_fm_scan_pool *fmpl1, *fmpl2;
        struct ubi_fm_ec *fmec;
        struct ubi_fm_volhdr *fmvhdr;
        struct ubi_fm_eba *fm_eba;
        int ret, i, j, pool_size, wl_pool_size;
        size_t fm_pos = 0, fm_size = ubi->fm_size;
        void *fm_raw = ubi->fm_buf;

        memset(ubi->fm_used, 0, sizeof(ubi->fm_used));

        fm_pos += sizeof(struct ubi_fm_sb);
        if (fm_pos >= fm_size)
                goto fail_bad;

        fmhdr = (struct ubi_fm_hdr *)(fm_raw + fm_pos);
        fm_pos += sizeof(*fmhdr);
        if (fm_pos >= fm_size)
                goto fail_bad;

        if (be32_to_cpu(fmhdr->magic) != UBI_FM_HDR_MAGIC) {
                ubi_err("bad fastmap header magic: 0x%x, expected: 0x%x",
                        be32_to_cpu(fmhdr->magic), UBI_FM_HDR_MAGIC);
                goto fail_bad;
        }

        fmpl1 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
        fm_pos += sizeof(*fmpl1);
        if (fm_pos >= fm_size)
                goto fail_bad;
        if (be32_to_cpu(fmpl1->magic) != UBI_FM_POOL_MAGIC) {
                ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
                        be32_to_cpu(fmpl1->magic), UBI_FM_POOL_MAGIC);
                goto fail_bad;
        }

        fmpl2 = (struct ubi_fm_scan_pool *)(fm_raw + fm_pos);
        fm_pos += sizeof(*fmpl2);
        if (fm_pos >= fm_size)
                goto fail_bad;
        if (be32_to_cpu(fmpl2->magic) != UBI_FM_POOL_MAGIC) {
                ubi_err("bad fastmap pool magic: 0x%x, expected: 0x%x",
                        be32_to_cpu(fmpl2->magic), UBI_FM_POOL_MAGIC);
                goto fail_bad;
        }

        pool_size = be16_to_cpu(fmpl1->size);
        wl_pool_size = be16_to_cpu(fmpl2->size);
        fm->max_pool_size = be16_to_cpu(fmpl1->max_size);
        fm->max_wl_pool_size = be16_to_cpu(fmpl2->max_size);

        if (pool_size > UBI_FM_MAX_POOL_SIZE || pool_size < 0) {
                ubi_err("bad pool size: %i", pool_size);
                goto fail_bad;
        }

        if (wl_pool_size > UBI_FM_MAX_POOL_SIZE || wl_pool_size < 0) {
                ubi_err("bad WL pool size: %i", wl_pool_size);
                goto fail_bad;
        }

        if (fm->max_pool_size > UBI_FM_MAX_POOL_SIZE ||
            fm->max_pool_size < 0) {
                ubi_err("bad maximal pool size: %i", fm->max_pool_size);
                goto fail_bad;
        }

        if (fm->max_wl_pool_size > UBI_FM_MAX_POOL_SIZE ||
            fm->max_wl_pool_size < 0) {
                ubi_err("bad maximal WL pool size: %i", fm->max_wl_pool_size);
                goto fail_bad;
        }

        /* read EC values from free list */
        for (i = 0; i < be32_to_cpu(fmhdr->free_peb_count); i++) {
                fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
                fm_pos += sizeof(*fmec);
                if (fm_pos >= fm_size)
                        goto fail_bad;
        }

        /* read EC values from used list */
        for (i = 0; i < be32_to_cpu(fmhdr->used_peb_count); i++) {
                fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
                fm_pos += sizeof(*fmec);
                if (fm_pos >= fm_size)
                        goto fail_bad;

                generic_set_bit(be32_to_cpu(fmec->pnum), ubi->fm_used);
        }

        /* read EC values from scrub list */
        for (i = 0; i < be32_to_cpu(fmhdr->scrub_peb_count); i++) {
                fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
                fm_pos += sizeof(*fmec);
                if (fm_pos >= fm_size)
                        goto fail_bad;
        }

        /* read EC values from erase list */
        for (i = 0; i < be32_to_cpu(fmhdr->erase_peb_count); i++) {
                fmec = (struct ubi_fm_ec *)(fm_raw + fm_pos);
                fm_pos += sizeof(*fmec);
                if (fm_pos >= fm_size)
                        goto fail_bad;
        }

        /* Iterate over all volumes and read their EBA table */
        for (i = 0; i < be32_to_cpu(fmhdr->vol_count); i++) {
                u32 vol_id, vol_type, used, reserved;

                fmvhdr = (struct ubi_fm_volhdr *)(fm_raw + fm_pos);
                fm_pos += sizeof(*fmvhdr);
                if (fm_pos >= fm_size)
                        goto fail_bad;

                if (be32_to_cpu(fmvhdr->magic) != UBI_FM_VHDR_MAGIC) {
                        ubi_err("bad fastmap vol header magic: 0x%x, " \
                                "expected: 0x%x",
                                be32_to_cpu(fmvhdr->magic), UBI_FM_VHDR_MAGIC);
                        goto fail_bad;
                }

                vol_id = be32_to_cpu(fmvhdr->vol_id);
                vol_type = fmvhdr->vol_type;
                used = be32_to_cpu(fmvhdr->used_ebs);

                fm_eba = (struct ubi_fm_eba *)(fm_raw + fm_pos);
                fm_pos += sizeof(*fm_eba);
                fm_pos += (sizeof(__be32) * be32_to_cpu(fm_eba->reserved_pebs));
                if (fm_pos >= fm_size)
                        goto fail_bad;

                if (be32_to_cpu(fm_eba->magic) != UBI_FM_EBA_MAGIC) {
                        ubi_err("bad fastmap EBA header magic: 0x%x, " \
                                "expected: 0x%x",
                                be32_to_cpu(fm_eba->magic), UBI_FM_EBA_MAGIC);
                        goto fail_bad;
                }

                reserved = be32_to_cpu(fm_eba->reserved_pebs);
                ubi_dbg("FA: vol %u used %u res: %u", vol_id, used, reserved);
                for (j = 0; j < reserved; j++) {
                        int pnum = be32_to_cpu(fm_eba->pnum[j]);

                        if ((int)be32_to_cpu(fm_eba->pnum[j]) < 0)
                                continue;

                        if (!__test_and_clear_bit(pnum, ubi->fm_used))
                                continue;

                        /*
                         * We only handle static volumes so used_ebs
                         * needs to be handed in. And we do not assign
                         * the reserved blocks
                         */
                        if (j >= used)
                                continue;

                        ret = assign_aeb_to_av(ubi, pnum, j, vol_id,
                                               vol_type, used);
                        if (!ret)
                                continue;

                        /*
                         * Nasty: The fastmap claims that the volume
                         * has one block more than it, but that block
                         * is always empty and the other blocks have
                         * the correct number of total LEBs in the
                         * headers. Deal with it.
                         */
                        if (ret != UBI_IO_FF && j != used - 1)
                                goto fail_bad;
                        ubi_dbg("FA: Vol: %u Ignoring empty LEB %d of %d",
                                vol_id, j, used);
                }
        }

        ret = scan_pool(ubi, fmpl1->pebs, pool_size);
        if (ret)
                goto fail;

        ret = scan_pool(ubi, fmpl2->pebs, wl_pool_size);
        if (ret)
                goto fail;

#ifdef CHECKME
        /*
         * If fastmap is leaking PEBs (must not happen), raise a
         * fat warning and fall back to scanning mode.
         * We do this here because in ubi_wl_init() it's too late
         * and we cannot fall back to scanning.
         */
        if (WARN_ON(count_fastmap_pebs(ai) != ubi->peb_count -
                    ai->bad_peb_count - fm->used_blocks))
                goto fail_bad;
#endif

        return 0;

fail_bad:
        ret = UBI_BAD_FASTMAP;
fail:
        return ret;
}

static int ubi_scan_fastmap(struct ubi_scan_info *ubi,
                            struct ubi_attach_info *ai,
                            int fm_anchor)
{
        struct ubi_fm_sb *fmsb, *fmsb2;
        struct ubi_vid_hdr *vh;
        struct ubi_fastmap_layout *fm;
        int i, used_blocks, pnum, ret = 0;
        size_t fm_size;
        __be32 crc, tmp_crc;
        unsigned long long sqnum = 0;

        fmsb = &ubi->fm_sb;
        fm = &ubi->fm_layout;

        ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
        if (ret && ret != UBI_IO_BITFLIPS)
                goto free_fm_sb;
        else if (ret == UBI_IO_BITFLIPS)
                fm->to_be_tortured[0] = 1;

        if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
                ubi_err("bad super block magic: 0x%x, expected: 0x%x",
                        be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
                ret = UBI_BAD_FASTMAP;
                goto free_fm_sb;
        }

        if (fmsb->version != UBI_FM_FMT_VERSION) {
                ubi_err("bad fastmap version: %i, expected: %i",
                        fmsb->version, UBI_FM_FMT_VERSION);
                ret = UBI_BAD_FASTMAP;
                goto free_fm_sb;
        }

        used_blocks = be32_to_cpu(fmsb->used_blocks);
        if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
                ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
                ret = UBI_BAD_FASTMAP;
                goto free_fm_sb;
        }

        fm_size = ubi->leb_size * used_blocks;
        if (fm_size != ubi->fm_size) {
                ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
                        ubi->fm_size);
                ret = UBI_BAD_FASTMAP;
                goto free_fm_sb;
        }

        vh = &ubi->fm_vh;

        for (i = 0; i < used_blocks; i++) {
                pnum = be32_to_cpu(fmsb->block_loc[i]);

                if (ubi_io_is_bad(ubi, pnum)) {
                        ret = UBI_BAD_FASTMAP;
                        goto free_hdr;
                }

#ifdef LATER
                int image_seq;
                ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
                if (ret && ret != UBI_IO_BITFLIPS) {
                        ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
                                i, pnum);
                        if (ret > 0)
                                ret = UBI_BAD_FASTMAP;
                        goto free_hdr;
                } else if (ret == UBI_IO_BITFLIPS)
                        fm->to_be_tortured[i] = 1;

                image_seq = be32_to_cpu(ech->image_seq);
                if (!ubi->image_seq)
                        ubi->image_seq = image_seq;
                /*
                 * Older UBI implementations have image_seq set to zero, so
                 * we shouldn't fail if image_seq == 0.
                 */
                if (image_seq && (image_seq != ubi->image_seq)) {
                        ubi_err("wrong image seq:%d instead of %d",
                                be32_to_cpu(ech->image_seq), ubi->image_seq);
                        ret = UBI_BAD_FASTMAP;
                        goto free_hdr;
                }
#endif
                ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
                if (ret && ret != UBI_IO_BITFLIPS) {
                        ubi_err("unable to read fastmap block# %i (PEB: %i)",
                                i, pnum);
                        goto free_hdr;
                }

                /*
                 * Mainline code rescans the anchor header. We've done
                 * that already so we merily copy it over.
                 */
                if (pnum == fm_anchor)
                        memcpy(vh, ubi->blockinfo + pnum, sizeof(*fm));

                if (i == 0) {
                        if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
                                ubi_err("bad fastmap anchor vol_id: 0x%x," \
                                        " expected: 0x%x",
                                        be32_to_cpu(vh->vol_id),
                                        UBI_FM_SB_VOLUME_ID);
                                ret = UBI_BAD_FASTMAP;
                                goto free_hdr;
                        }
                } else {
                        if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
                                ubi_err("bad fastmap data vol_id: 0x%x," \
                                        " expected: 0x%x",
                                        be32_to_cpu(vh->vol_id),
                                        UBI_FM_DATA_VOLUME_ID);
                                ret = UBI_BAD_FASTMAP;
                                goto free_hdr;
                        }
                }

                if (sqnum < be64_to_cpu(vh->sqnum))
                        sqnum = be64_to_cpu(vh->sqnum);

                ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
                                  ubi->leb_start, ubi->leb_size);
                if (ret && ret != UBI_IO_BITFLIPS) {
                        ubi_err("unable to read fastmap block# %i (PEB: %i, " \
                                "err: %i)", i, pnum, ret);
                        goto free_hdr;
                }
        }

        fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
        tmp_crc = be32_to_cpu(fmsb2->data_crc);
        fmsb2->data_crc = 0;
        crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
        if (crc != tmp_crc) {
                ubi_err("fastmap data CRC is invalid");
                ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
                ret = UBI_BAD_FASTMAP;
                goto free_hdr;
        }

        fmsb2->sqnum = sqnum;

        fm->used_blocks = used_blocks;

        ret = ubi_attach_fastmap(ubi, ai, fm);
        if (ret) {
                if (ret > 0)
                        ret = UBI_BAD_FASTMAP;
                goto free_hdr;
        }

        ubi->fm = fm;
        ubi->fm_pool.max_size = ubi->fm->max_pool_size;
        ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
        ubi_msg("attached by fastmap %uMB %u blocks",
                ubi->fsize_mb, ubi->peb_count);
        ubi_dbg("fastmap pool size: %d", ubi->fm_pool.max_size);
        ubi_dbg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);

out:
        if (ret)
                ubi_err("Attach by fastmap failed, doing a full scan!");
        return ret;

free_hdr:
free_fm_sb:
        goto out;
}

/*
 * Scan the flash and attempt to attach via fastmap
 */
static void ipl_scan(struct ubi_scan_info *ubi)
{
        unsigned int pnum;
        int res;

        /*
         * Scan first for the fastmap super block
         */
        for (pnum = 0; pnum < UBI_FM_MAX_START; pnum++) {
                res = ubi_scan_vid_hdr(ubi, ubi->blockinfo + pnum, pnum);
                /*
                 * We ignore errors here as we are meriliy scanning
                 * the headers.
                 */
                if (res != UBI_FASTMAP_ANCHOR)
                        continue;

                /*
                 * If fastmap is disabled, continue scanning. This
                 * might happen because the previous attempt failed or
                 * the caller disabled it right away.
                 */
                if (!ubi->fm_enabled)
                        continue;

                /*
                 * Try to attach the fastmap, if that fails continue
                 * scanning.
                 */
                if (!ubi_scan_fastmap(ubi, NULL, pnum))
                        return;
                /*
                 * Fastmap failed. Clear everything we have and start
                 * over. We are paranoid and do not trust anything.
                 */
                memset(ubi->volinfo, 0, sizeof(ubi->volinfo));
                pnum = 0;
                break;
        }

        /*
         * Continue scanning, ignore errors, we might find what we are
         * looking for,
         */
        for (; pnum < ubi->peb_count; pnum++)
                ubi_scan_vid_hdr(ubi, ubi->blockinfo + pnum, pnum);
}

/*
 * Load a logical block of a volume into memory
 */
static int ubi_load_block(struct ubi_scan_info *ubi, uint8_t *laddr,
                          struct ubi_vol_info *vi, u32 vol_id, u32 lnum,
                          u32 last)
{
        struct ubi_vid_hdr *vh, *vrepl;
        u32 pnum, crc, dlen;

retry:
        /*
         * If this is a fastmap run, we try to rescan full, otherwise
         * we simply give up.
         */
        if (!test_bit(lnum, vi->found)) {
                ubi_warn("LEB %d of %d is missing", lnum, last);
                return -EINVAL;
        }

        pnum = vi->lebs_to_pebs[lnum];

        ubi_dbg("Load vol %u LEB %u PEB %u", vol_id, lnum, pnum);

        if (ubi_io_is_bad(ubi, pnum)) {
                ubi_warn("Corrupted mapping block %d PB %d\n", lnum, pnum);
                return -EINVAL;
        }

        if (test_bit(pnum, ubi->corrupt))
                goto find_other;

        /*
         * Lets try to read that block
         */
        vh = ubi->blockinfo + pnum;

        if (!test_bit(pnum, ubi->scanned)) {
                ubi_warn("Vol: %u LEB %u PEB %u not yet scanned", vol_id,
                         lnum, pnum);
                if (ubi_rescan_fm_vid_hdr(ubi, vh, pnum, vol_id, lnum))
                        goto find_other;
        }

        /*
         * Check, if the total number of blocks is correct
         */
        if (be32_to_cpu(vh->used_ebs) != last) {
                ubi_dbg("Block count missmatch.");
                ubi_dbg("vh->used_ebs: %d nrblocks: %d",
                        be32_to_cpu(vh->used_ebs), last);
                generic_set_bit(pnum, ubi->corrupt);
                goto find_other;
        }

        /*
         * Get the data length of this block.
         */
        dlen = be32_to_cpu(vh->data_size);

        /*
         * Read the data into RAM. We ignore the return value
         * here as the only thing which might go wrong are
         * bitflips. Try nevertheless.
         */
        ubi_io_read(ubi, laddr, pnum, ubi->leb_start, dlen);

        /* Calculate CRC over the data */
        crc = crc32(UBI_CRC32_INIT, laddr, dlen);

        if (crc != be32_to_cpu(vh->data_crc)) {
                ubi_warn("Vol: %u LEB %u PEB %u data CRC failure", vol_id,
                         lnum, pnum);
                generic_set_bit(pnum, ubi->corrupt);
                goto find_other;
        }

        /* We are good. Return the data length we read */
        return dlen;

find_other:
        ubi_dbg("Find replacement for LEB %u PEB %u", lnum, pnum);
        generic_clear_bit(lnum, vi->found);
        vrepl = NULL;

        for (pnum = 0; pnum < ubi->peb_count; pnum++) {
                struct ubi_vid_hdr *tmp = ubi->blockinfo + pnum;
                u32 t_vol_id = be32_to_cpu(tmp->vol_id);
                u32 t_lnum = be32_to_cpu(tmp->lnum);

                if (test_bit(pnum, ubi->corrupt))
                        continue;

                if (t_vol_id != vol_id || t_lnum != lnum)
                        continue;

                if (!test_bit(pnum, ubi->scanned)) {
                        ubi_warn("Vol: %u LEB %u PEB %u not yet scanned",
                                 vol_id, lnum, pnum);
                        if (ubi_rescan_fm_vid_hdr(ubi, tmp, pnum, vol_id, lnum))
                                continue;
                }

                /*
                 * We found one. If its the first, assign it otherwise
                 * compare the sqnum
                 */
                generic_set_bit(lnum, vi->found);

                if (!vrepl) {
                        vrepl = tmp;
                        continue;
                }

                if (be64_to_cpu(vrepl->sqnum) < be64_to_cpu(tmp->sqnum))
                        vrepl = tmp;
        }

        if (vrepl) {
                /* Update the vi table */
                pnum = vrepl - ubi->blockinfo;
                vi->lebs_to_pebs[lnum] = pnum;
                ubi_dbg("Trying PEB %u for LEB %u", pnum, lnum);
                vh = vrepl;
        }
        goto retry;
}

/*
 * Load a volume into RAM
 */
static int ipl_load(struct ubi_scan_info *ubi, const u32 vol_id, uint8_t *laddr)
{
        struct ubi_vol_info *vi;
        u32 lnum, last, len;

        if (vol_id >= UBI_SPL_VOL_IDS)
                return -EINVAL;

        len = 0;
        vi = ubi->volinfo + vol_id;
        last = vi->last_block + 1;

        /* Read the blocks to RAM, check CRC */
        for (lnum = 0 ; lnum < last; lnum++) {
                int res = ubi_load_block(ubi, laddr, vi, vol_id, lnum, last);

                if (res < 0) {
                        ubi_warn("Failed to load volume %u", vol_id);
                        return res;
                }
                /* res is the data length of the read block */
                laddr += res;
                len += res;
        }
        return len;
}

int ubispl_load_volumes(struct ubispl_info *info, struct ubispl_load *lvols,
                        int nrvols)
{
        struct ubi_scan_info *ubi = info->ubi;
        int res, i, fastmap = info->fastmap;
        u32 fsize;

retry:
        /*
         * We do a partial initializiation of @ubi. Cleaning fm_buf is
         * not necessary.
         */
        memset(ubi, 0, offsetof(struct ubi_scan_info, fm_buf));

        ubi->read = info->read;

        /* Precalculate the offsets */
        ubi->vid_offset = info->vid_offset;
        ubi->leb_start = info->leb_start;
        ubi->leb_size = info->peb_size - ubi->leb_start;
        ubi->peb_count = info->peb_count;
        ubi->peb_offset = info->peb_offset;

#ifdef CONFIG_SPL_UBI_LOAD_BY_VOLNAME
        ubi->vtbl_valid = 0;
#endif

        fsize = info->peb_size * info->peb_count;
        ubi->fsize_mb = fsize >> 20;

        /* Fastmap init */
        ubi->fm_size = ubi_calc_fm_size(ubi);
        ubi->fm_enabled = fastmap;

        for (i = 0; i < nrvols; i++) {
                struct ubispl_load *lv = lvols + i;

                generic_set_bit(lv->vol_id, ubi->toload);
        }

        ipl_scan(ubi);

        for (i = 0; i < nrvols; i++) {
                struct ubispl_load *lv = lvols + i;

#ifdef CONFIG_SPL_UBI_LOAD_BY_VOLNAME
                if (lv->vol_id == -1) {
                        for (int j = 0; j < UBI_SPL_VOL_IDS; j++) {
                                int len = be16_to_cpu(ubi->vtbl[j].name_len);

                                if (strncmp(lv->name,
                                            ubi->vtbl[j].name,
                                            len) == 0) {
                                        lv->vol_id = j;
                                        break;
                                }
                        }
                }
                ubi_msg("Loading VolName %s (VolId #%d)", lv->name, lv->vol_id);
#else
                ubi_msg("Loading VolId #%d", lv->vol_id);
#endif
                res = ipl_load(ubi, lv->vol_id, lv->load_addr);
                if (res < 0) {
                        if (fastmap) {
                                fastmap = 0;
                                goto retry;
                        }
                        ubi_warn("Failed");
                        return res;
                }
        }
        return 0;
}