mtd_readtest.c

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/*
 * Copyright (C) 2006-2008 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; see the file COPYING. If not, write to the Free Software
 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Check MTD device read.
 *
 * Author: Adrian Hunter <[email protected]>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
#include <linux/mtd/mtd.h>
#include <linux/slab.h>
#include <linux/sched.h>

#define PRINT_PREF KERN_INFO "mtd_readtest: "

static int dev = -EINVAL;
module_param(dev, int, S_IRUGO);
MODULE_PARM_DESC(dev, "MTD device number to use");

static struct mtd_info *mtd;
static unsigned char *iobuf;
static unsigned char *iobuf1;
static unsigned char *bbt;

static int pgsize;
static int ebcnt;
static int pgcnt;

static int read_eraseblock_by_page(int ebnum)
{
    size_t read;
    int i, ret, err = 0;
    loff_t addr = ebnum * mtd->erasesize;
    void *buf = iobuf;
    void *oobbuf = iobuf1;

    for (i = 0; i < pgcnt; i++) {
        memset(buf, 0 , pgcnt);
        ret = mtd_read(mtd, addr, pgsize, &read, buf);
        if (ret == -EUCLEAN)
            ret = 0;
        if (ret || read != pgsize) {
            printk(PRINT_PREF "error: read failed at %#llx\n",
                   (long long)addr);
            if (!err)
                err = ret;
            if (!err)
                err = -EINVAL;
        }
        if (mtd->oobsize) {
            struct mtd_oob_ops ops;

            ops.mode      = MTD_OPS_PLACE_OOB;
            ops.len       = 0;
            ops.retlen    = 0;
            ops.ooblen    = mtd->oobsize;
            ops.oobretlen = 0;
            ops.ooboffs   = 0;
            ops.datbuf    = NULL;
            ops.oobbuf    = oobbuf;
            ret = mtd_read_oob(mtd, addr, &ops);
            if ((ret && !mtd_is_bitflip(ret)) ||
                    ops.oobretlen != mtd->oobsize) {
                printk(PRINT_PREF "error: read oob failed at "
                          "%#llx\n", (long long)addr);
                if (!err)
                    err = ret;
                if (!err)
                    err = -EINVAL;
            }
            oobbuf += mtd->oobsize;
        }
        addr += pgsize;
        buf += pgsize;
    }

    return err;
}

static void dump_eraseblock(int ebnum)
{
    int i, j, n;
    char line[128];
    int pg, oob;

    printk(PRINT_PREF "dumping eraseblock %d\n", ebnum);
    n = mtd->erasesize;
    for (i = 0; i < n;) {
        char *p = line;

        p += sprintf(p, "%05x: ", i);
        for (j = 0; j < 32 && i < n; j++, i++)
            p += sprintf(p, "%02x", (unsigned int)iobuf[i]);
        printk(KERN_CRIT "%s\n", line);
        cond_resched();
    }
    if (!mtd->oobsize)
        return;
    printk(PRINT_PREF "dumping oob from eraseblock %d\n", ebnum);
    n = mtd->oobsize;
    for (pg = 0, i = 0; pg < pgcnt; pg++)
        for (oob = 0; oob < n;) {
            char *p = line;

            p += sprintf(p, "%05x: ", i);
            for (j = 0; j < 32 && oob < n; j++, oob++, i++)
                p += sprintf(p, "%02x",
                         (unsigned int)iobuf1[i]);
            printk(KERN_CRIT "%s\n", line);
            cond_resched();
        }
}

static int is_block_bad(int ebnum)
{
    loff_t addr = ebnum * mtd->erasesize;
    int ret;

    ret = mtd_block_isbad(mtd, addr);
    if (ret)
        printk(PRINT_PREF "block %d is bad\n", ebnum);
    return ret;
}

static int scan_for_bad_eraseblocks(void)
{
    int i, bad = 0;

    bbt = kzalloc(ebcnt, GFP_KERNEL);
    if (!bbt) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        return -ENOMEM;
    }

    if (!mtd_can_have_bb(mtd))
        return 0;

    printk(PRINT_PREF "scanning for bad eraseblocks\n");
    for (i = 0; i < ebcnt; ++i) {
        bbt[i] = is_block_bad(i) ? 1 : 0;
        if (bbt[i])
            bad += 1;
        cond_resched();
    }
    printk(PRINT_PREF "scanned %d eraseblocks, %d are bad\n", i, bad);
    return 0;
}

static int __init mtd_readtest_init(void)
{
    uint64_t tmp;
    int err, i;

    printk(KERN_INFO "\n");
    printk(KERN_INFO "=================================================\n");

    if (dev < 0) {
        printk(PRINT_PREF "Please specify a valid mtd-device via module paramter\n");
        return -EINVAL;
    }

    printk(PRINT_PREF "MTD device: %d\n", dev);

    mtd = get_mtd_device(NULL, dev);
    if (IS_ERR(mtd)) {
        err = PTR_ERR(mtd);
        printk(PRINT_PREF "error: Cannot get MTD device\n");
        return err;
    }

    if (mtd->writesize == 1) {
        printk(PRINT_PREF "not NAND flash, assume page size is 512 "
               "bytes.\n");
        pgsize = 512;
    } else
        pgsize = mtd->writesize;

    tmp = mtd->size;
    do_div(tmp, mtd->erasesize);
    ebcnt = tmp;
    pgcnt = mtd->erasesize / pgsize;

    printk(PRINT_PREF "MTD device size %llu, eraseblock size %u, "
           "page size %u, count of eraseblocks %u, pages per "
           "eraseblock %u, OOB size %u\n",
           (unsigned long long)mtd->size, mtd->erasesize,
           pgsize, ebcnt, pgcnt, mtd->oobsize);

    err = -ENOMEM;
    iobuf = kmalloc(mtd->erasesize, GFP_KERNEL);
    if (!iobuf) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        goto out;
    }
    iobuf1 = kmalloc(mtd->erasesize, GFP_KERNEL);
    if (!iobuf1) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        goto out;
    }

    err = scan_for_bad_eraseblocks();
    if (err)
        goto out;

    /* Read all eraseblocks 1 page at a time */
    printk(PRINT_PREF "testing page read\n");
    for (i = 0; i < ebcnt; ++i) {
        int ret;

        if (bbt[i])
            continue;
        ret = read_eraseblock_by_page(i);
        if (ret) {
            dump_eraseblock(i);
            if (!err)
                err = ret;
        }
        cond_resched();
    }

    if (err)
        printk(PRINT_PREF "finished with errors\n");
    else
        printk(PRINT_PREF "finished\n");

out:

    kfree(iobuf);
    kfree(iobuf1);
    kfree(bbt);
    put_mtd_device(mtd);
    if (err)
        printk(PRINT_PREF "error %d occurred\n", err);
    printk(KERN_INFO "=================================================\n");
    return err;
}
module_init(mtd_readtest_init);

static void __exit mtd_readtest_exit(void)
{
    return;
}
module_exit(mtd_readtest_exit);

MODULE_DESCRIPTION("Read test module");
MODULE_AUTHOR("Adrian Hunter");
MODULE_LICENSE("GPL");