mtd_torturetest.c

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/*
 * Copyright (C) 2006-2008 Artem Bityutskiy
 * Copyright (C) 2006-2008 Jarkko Lavinen
 * Copyright (C) 2006-2008 Adrian Hunter
 *
 * 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.
 *
 * Authors: Artem Bityutskiy, Jarkko Lavinen, Adria Hunter
 *
 * WARNING: this test program may kill your flash and your device. Do not
 * use it unless you know what you do. Authors are not responsible for any
 * damage caused by this program.
 */

#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_torturetest: "
#define RETRIES 3

static int eb = 8;
module_param(eb, int, S_IRUGO);
MODULE_PARM_DESC(eb, "eraseblock number within the selected MTD device");

static int ebcnt = 32;
module_param(ebcnt, int, S_IRUGO);
MODULE_PARM_DESC(ebcnt, "number of consecutive eraseblocks to torture");

static int pgcnt;
module_param(pgcnt, int, S_IRUGO);
MODULE_PARM_DESC(pgcnt, "number of pages per eraseblock to torture (0 => all)");

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

static int gran = 512;
module_param(gran, int, S_IRUGO);
MODULE_PARM_DESC(gran, "how often the status information should be printed");

static int check = 1;
module_param(check, int, S_IRUGO);
MODULE_PARM_DESC(check, "if the written data should be checked");

static unsigned int cycles_count;
module_param(cycles_count, uint, S_IRUGO);
MODULE_PARM_DESC(cycles_count, "how many erase cycles to do "
                   "(infinite by default)");

static struct mtd_info *mtd;

/* This buffer contains 0x555555...0xAAAAAA... pattern */
static unsigned char *patt_5A5;
/* This buffer contains 0xAAAAAA...0x555555... pattern */
static unsigned char *patt_A5A;
/* This buffer contains all 0xFF bytes */
static unsigned char *patt_FF;
/* This a temporary buffer is use when checking data */
static unsigned char *check_buf;
/* How many erase cycles were done */
static unsigned int erase_cycles;

static int pgsize;
static struct timeval start, finish;

static void report_corrupt(unsigned char *read, unsigned char *written);

static inline void start_timing(void)
{
    do_gettimeofday(&start);
}

static inline void stop_timing(void)
{
    do_gettimeofday(&finish);
}

/*
 * Erase eraseblock number @ebnum.
 */
static inline int erase_eraseblock(int ebnum)
{
    int err;
    struct erase_info ei;
    loff_t addr = ebnum * mtd->erasesize;

    memset(&ei, 0, sizeof(struct erase_info));
    ei.mtd  = mtd;
    ei.addr = addr;
    ei.len  = mtd->erasesize;

    err = mtd_erase(mtd, &ei);
    if (err) {
        printk(PRINT_PREF "error %d while erasing EB %d\n", err, ebnum);
        return err;
    }

    if (ei.state == MTD_ERASE_FAILED) {
        printk(PRINT_PREF "some erase error occurred at EB %d\n",
               ebnum);
        return -EIO;
    }

    return 0;
}

/*
 * Check that the contents of eraseblock number @enbum is equivalent to the
 * @buf buffer.
 */
static inline int check_eraseblock(int ebnum, unsigned char *buf)
{
    int err, retries = 0;
    size_t read;
    loff_t addr = ebnum * mtd->erasesize;
    size_t len = mtd->erasesize;

    if (pgcnt) {
        addr = (ebnum + 1) * mtd->erasesize - pgcnt * pgsize;
        len = pgcnt * pgsize;
    }

retry:
    err = mtd_read(mtd, addr, len, &read, check_buf);
    if (mtd_is_bitflip(err))
        printk(PRINT_PREF "single bit flip occurred at EB %d "
               "MTD reported that it was fixed.\n", ebnum);
    else if (err) {
        printk(PRINT_PREF "error %d while reading EB %d, "
               "read %zd\n", err, ebnum, read);
        return err;
    }

    if (read != len) {
        printk(PRINT_PREF "failed to read %zd bytes from EB %d, "
               "read only %zd, but no error reported\n",
               len, ebnum, read);
        return -EIO;
    }

    if (memcmp(buf, check_buf, len)) {
        printk(PRINT_PREF "read wrong data from EB %d\n", ebnum);
        report_corrupt(check_buf, buf);

        if (retries++ < RETRIES) {
            /* Try read again */
            yield();
            printk(PRINT_PREF "re-try reading data from EB %d\n",
                   ebnum);
            goto retry;
        } else {
            printk(PRINT_PREF "retried %d times, still errors, "
                   "give-up\n", RETRIES);
            return -EINVAL;
        }
    }

    if (retries != 0)
        printk(PRINT_PREF "only attempt number %d was OK (!!!)\n",
               retries);

    return 0;
}

static inline int write_pattern(int ebnum, void *buf)
{
    int err;
    size_t written;
    loff_t addr = ebnum * mtd->erasesize;
    size_t len = mtd->erasesize;

    if (pgcnt) {
        addr = (ebnum + 1) * mtd->erasesize - pgcnt * pgsize;
        len = pgcnt * pgsize;
    }
    err = mtd_write(mtd, addr, len, &written, buf);
    if (err) {
        printk(PRINT_PREF "error %d while writing EB %d, written %zd"
              " bytes\n", err, ebnum, written);
        return err;
    }
    if (written != len) {
        printk(PRINT_PREF "written only %zd bytes of %zd, but no error"
               " reported\n", written, len);
        return -EIO;
    }

    return 0;
}

static int __init tort_init(void)
{
    int err = 0, i, infinite = !cycles_count;
    int bad_ebs[ebcnt];

    printk(KERN_INFO "\n");
    printk(KERN_INFO "=================================================\n");
    printk(PRINT_PREF "Warning: this program is trying to wear out your "
           "flash, stop it if this is not wanted.\n");

    if (dev < 0) {
        printk(PRINT_PREF "Please specify a valid mtd-device via module paramter\n");
        printk(KERN_CRIT "CAREFUL: This test wipes all data on the specified MTD device!\n");
        return -EINVAL;
    }

    printk(PRINT_PREF "MTD device: %d\n", dev);
    printk(PRINT_PREF "torture %d eraseblocks (%d-%d) of mtd%d\n",
           ebcnt, eb, eb + ebcnt - 1, dev);
    if (pgcnt)
        printk(PRINT_PREF "torturing just %d pages per eraseblock\n",
            pgcnt);
    printk(PRINT_PREF "write verify %s\n", check ? "enabled" : "disabled");

    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;

    if (pgcnt && (pgcnt > mtd->erasesize / pgsize || pgcnt < 0)) {
        printk(PRINT_PREF "error: invalid pgcnt value %d\n", pgcnt);
        goto out_mtd;
    }

    err = -ENOMEM;
    patt_5A5 = kmalloc(mtd->erasesize, GFP_KERNEL);
    if (!patt_5A5) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        goto out_mtd;
    }

    patt_A5A = kmalloc(mtd->erasesize, GFP_KERNEL);
    if (!patt_A5A) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        goto out_patt_5A5;
    }

    patt_FF = kmalloc(mtd->erasesize, GFP_KERNEL);
    if (!patt_FF) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        goto out_patt_A5A;
    }

    check_buf = kmalloc(mtd->erasesize, GFP_KERNEL);
    if (!check_buf) {
        printk(PRINT_PREF "error: cannot allocate memory\n");
        goto out_patt_FF;
    }

    err = 0;

    /* Initialize patterns */
    memset(patt_FF, 0xFF, mtd->erasesize);
    for (i = 0; i < mtd->erasesize / pgsize; i++) {
        if (!(i & 1)) {
            memset(patt_5A5 + i * pgsize, 0x55, pgsize);
            memset(patt_A5A + i * pgsize, 0xAA, pgsize);
        } else {
            memset(patt_5A5 + i * pgsize, 0xAA, pgsize);
            memset(patt_A5A + i * pgsize, 0x55, pgsize);
        }
    }

    /*
     * Check if there is a bad eraseblock among those we are going to test.
     */
    memset(&bad_ebs[0], 0, sizeof(int) * ebcnt);
    if (mtd_can_have_bb(mtd)) {
        for (i = eb; i < eb + ebcnt; i++) {
            err = mtd_block_isbad(mtd, (loff_t)i * mtd->erasesize);

            if (err < 0) {
                printk(PRINT_PREF "block_isbad() returned %d "
                       "for EB %d\n", err, i);
                goto out;
            }

            if (err) {
                printk("EB %d is bad. Skip it.\n", i);
                bad_ebs[i - eb] = 1;
            }
        }
    }

    start_timing();
    while (1) {
        int i;
        void *patt;

        /* Erase all eraseblocks */
        for (i = eb; i < eb + ebcnt; i++) {
            if (bad_ebs[i - eb])
                continue;
            err = erase_eraseblock(i);
            if (err)
                goto out;
            cond_resched();
        }

        /* Check if the eraseblocks contain only 0xFF bytes */
        if (check) {
            for (i = eb; i < eb + ebcnt; i++) {
                if (bad_ebs[i - eb])
                    continue;
                err = check_eraseblock(i, patt_FF);
                if (err) {
                    printk(PRINT_PREF "verify failed"
                           " for 0xFF... pattern\n");
                    goto out;
                }
                cond_resched();
            }
        }

        /* Write the pattern */
        for (i = eb; i < eb + ebcnt; i++) {
            if (bad_ebs[i - eb])
                continue;
            if ((eb + erase_cycles) & 1)
                patt = patt_5A5;
            else
                patt = patt_A5A;
            err = write_pattern(i, patt);
            if (err)
                goto out;
            cond_resched();
        }

        /* Verify what we wrote */
        if (check) {
            for (i = eb; i < eb + ebcnt; i++) {
                if (bad_ebs[i - eb])
                    continue;
                if ((eb + erase_cycles) & 1)
                    patt = patt_5A5;
                else
                    patt = patt_A5A;
                err = check_eraseblock(i, patt);
                if (err) {
                    printk(PRINT_PREF "verify failed for %s"
                           " pattern\n",
                           ((eb + erase_cycles) & 1) ?
                           "0x55AA55..." : "0xAA55AA...");
                    goto out;
                }
                cond_resched();
            }
        }

        erase_cycles += 1;

        if (erase_cycles % gran == 0) {
            long ms;

            stop_timing();
            ms = (finish.tv_sec - start.tv_sec) * 1000 +
                 (finish.tv_usec - start.tv_usec) / 1000;
            printk(PRINT_PREF "%08u erase cycles done, took %lu "
                   "milliseconds (%lu seconds)\n",
                   erase_cycles, ms, ms / 1000);
            start_timing();
        }

        if (!infinite && --cycles_count == 0)
            break;
    }
out:

    printk(PRINT_PREF "finished after %u erase cycles\n",
           erase_cycles);
    kfree(check_buf);
out_patt_FF:
    kfree(patt_FF);
out_patt_A5A:
    kfree(patt_A5A);
out_patt_5A5:
    kfree(patt_5A5);
out_mtd:
    put_mtd_device(mtd);
    if (err)
        printk(PRINT_PREF "error %d occurred during torturing\n", err);
    printk(KERN_INFO "=================================================\n");
    return err;
}
module_init(tort_init);

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

static int countdiffs(unsigned char *buf, unsigned char *check_buf,
              unsigned offset, unsigned len, unsigned *bytesp,
              unsigned *bitsp);
static void print_bufs(unsigned char *read, unsigned char *written, int start,
               int len);

/*
 * Report the detailed information about how the read EB differs from what was
 * written.
 */
static void report_corrupt(unsigned char *read, unsigned char *written)
{
    int i;
    int bytes, bits, pages, first;
    int offset, len;
    size_t check_len = mtd->erasesize;

    if (pgcnt)
        check_len = pgcnt * pgsize;

    bytes = bits = pages = 0;
    for (i = 0; i < check_len; i += pgsize)
        if (countdiffs(written, read, i, pgsize, &bytes,
                   &bits) >= 0)
            pages++;

    printk(PRINT_PREF "verify fails on %d pages, %d bytes/%d bits\n",
           pages, bytes, bits);
    printk(PRINT_PREF "The following is a list of all differences between"
           " what was read from flash and what was expected\n");

    for (i = 0; i < check_len; i += pgsize) {
        cond_resched();
        bytes = bits = 0;
        first = countdiffs(written, read, i, pgsize, &bytes,
                   &bits);
        if (first < 0)
            continue;

        printk("-------------------------------------------------------"
               "----------------------------------\n");

        printk(PRINT_PREF "Page %zd has %d bytes/%d bits failing verify,"
               " starting at offset 0x%x\n",
               (mtd->erasesize - check_len + i) / pgsize,
               bytes, bits, first);

        offset = first & ~0x7;
        len = ((first + bytes) | 0x7) + 1 - offset;

        print_bufs(read, written, offset, len);
    }
}

static void print_bufs(unsigned char *read, unsigned char *written, int start,
               int len)
{
    int i = 0, j1, j2;
    char *diff;

    printk("Offset       Read                          Written\n");
    while (i < len) {
        printk("0x%08x: ", start + i);
        diff = "   ";
        for (j1 = 0; j1 < 8 && i + j1 < len; j1++) {
            printk(" %02x", read[start + i + j1]);
            if (read[start + i + j1] != written[start + i + j1])
                diff = "***";
        }

        while (j1 < 8) {
            printk(" ");
            j1 += 1;
        }

        printk("  %s ", diff);

        for (j2 = 0; j2 < 8 && i + j2 < len; j2++)
            printk(" %02x", written[start + i + j2]);
        printk("\n");
        i += 8;
    }
}

/*
 * Count the number of differing bytes and bits and return the first differing
 * offset.
 */
static int countdiffs(unsigned char *buf, unsigned char *check_buf,
              unsigned offset, unsigned len, unsigned *bytesp,
              unsigned *bitsp)
{
    unsigned i, bit;
    int first = -1;

    for (i = offset; i < offset + len; i++)
        if (buf[i] != check_buf[i]) {
            first = i;
            break;
        }

    while (i < offset + len) {
        if (buf[i] != check_buf[i]) {
            (*bytesp)++;
            bit = 1;
            while (bit < 256) {
                if ((buf[i] & bit) != (check_buf[i] & bit))
                    (*bitsp)++;
                bit <<= 1;
            }
        }
        i++;
    }

    return first;
}

MODULE_DESCRIPTION("Eraseblock torturing module");
MODULE_AUTHOR("Artem Bityutskiy, Jarkko Lavinen, Adrian Hunter");
MODULE_LICENSE("GPL");