linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 *  linux/fs/hpfs/map.c

 *

 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999

 *

 *  mapping structures to memory with some minimal checks

 */

​

#include "hpfs_fn.h"

​

__le32 *hpfs_map_dnode_bitmap(struct super_block *s, struct quad_buffer_head *qbh)

{

    return hpfs_map_4sectors(s, hpfs_sb(s)->sb_dmap, qbh, 0);

}

​

__le32 *hpfs_map_bitmap(struct super_block *s, unsigned bmp_block,

             struct quad_buffer_head *qbh, char *id)

{

    secno sec;

    __le32 *ret;

    unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;

    if (hpfs_sb(s)->sb_chk) if (bmp_block >= n_bands) {

        hpfs_error(s, "hpfs_map_bitmap called with bad parameter: %08x at %s", bmp_block, id);

        return NULL;

    }

    sec = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);

    if (!sec || sec > hpfs_sb(s)->sb_fs_size-4) {

        hpfs_error(s, "invalid bitmap block pointer %08x -> %08x at %s", bmp_block, sec, id);

        return NULL;

    }

    ret = hpfs_map_4sectors(s, sec, qbh, 4);

    if (ret) hpfs_prefetch_bitmap(s, bmp_block + 1);

    return ret;

}

​

void hpfs_prefetch_bitmap(struct super_block *s, unsigned bmp_block)

{

    unsigned to_prefetch, next_prefetch;

    unsigned n_bands = (hpfs_sb(s)->sb_fs_size + 0x3fff) >> 14;

    if (unlikely(bmp_block >= n_bands))

        return;

    to_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block]);

    if (unlikely(bmp_block + 1 >= n_bands))

        next_prefetch = 0;

    else

        next_prefetch = le32_to_cpu(hpfs_sb(s)->sb_bmp_dir[bmp_block + 1]);

    hpfs_prefetch_sectors(s, to_prefetch, 4 + 4 * (to_prefetch + 4 == next_prefetch));

}

​

/*

 * Load first code page into kernel memory, return pointer to 256-byte array,

 * first 128 bytes are uppercasing table for chars 128-255, next 128 bytes are

 * lowercasing table

 */

​

unsigned char *hpfs_load_code_page(struct super_block *s, secno cps)

{

    struct buffer_head *bh;

    secno cpds;

    unsigned cpi;

    unsigned char *ptr;

    unsigned char *cp_table;

    int i;

    struct code_page_data *cpd;

    struct code_page_directory *cp = hpfs_map_sector(s, cps, &bh, 0);

    if (!cp) return NULL;

    if (le32_to_cpu(cp->magic) != CP_DIR_MAGIC) {

        pr_err("Code page directory magic doesn't match (magic = %08x)\n",

            le32_to_cpu(cp->magic));

        brelse(bh);

        return NULL;

    }

    if (!le32_to_cpu(cp->n_code_pages)) {

        pr_err("n_code_pages == 0\n");

        brelse(bh);

        return NULL;

    }

    cpds = le32_to_cpu(cp->array[0].code_page_data);

    cpi = le16_to_cpu(cp->array[0].index);

    brelse(bh);

​

    if (cpi >= 3) {

        pr_err("Code page index out of array\n");

        return NULL;

    }

    if (!(cpd = hpfs_map_sector(s, cpds, &bh, 0))) return NULL;

    if (le16_to_cpu(cpd->offs[cpi]) > 0x178) {

        pr_err("Code page index out of sector\n");

        brelse(bh);

        return NULL;