root/drivers/mtd/tests/pagetest.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2006-2008 Nokia Corporation
 *
 * Test page read and write on MTD device.
 *
 * Author: Adrian Hunter <ext-adrian.hunter@nokia.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <asm/div64.h>
#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>
#include <linux/prandom.h>

#include "mtd_test.h"

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 *twopages;
static unsigned char *writebuf;
static unsigned char *boundary;
static unsigned char *bbt;

static int pgsize;
static int bufsize;
static int ebcnt;
static int pgcnt;
static int errcnt;
static struct rnd_state rnd_state;

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

        prandom_bytes_state(&rnd_state, writebuf, mtd->erasesize);
        cond_resched();
        return mtdtest_write(mtd, addr, mtd->erasesize, writebuf);
}

static int verify_eraseblock(int ebnum)
{
        uint32_t j;
        int err = 0, i;
        loff_t addr0, addrn;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;

        addr0 = 0;
        for (i = 0; i < ebcnt && bbt[i]; ++i)
                addr0 += mtd->erasesize;

        addrn = mtd->size;
        for (i = 0; i < ebcnt && bbt[ebcnt - i - 1]; ++i)
                addrn -= mtd->erasesize;

        prandom_bytes_state(&rnd_state, writebuf, mtd->erasesize);
        for (j = 0; j < pgcnt - 1; ++j, addr += pgsize) {
                /* Do a read to set the internal dataRAMs to different data */
                err = mtdtest_read(mtd, addr0, bufsize, twopages);
                if (err)
                        return err;
                err = mtdtest_read(mtd, addrn - bufsize, bufsize, twopages);
                if (err)
                        return err;
                memset(twopages, 0, bufsize);
                err = mtdtest_read(mtd, addr, bufsize, twopages);
                if (err)
                        break;
                if (memcmp(twopages, writebuf + (j * pgsize), bufsize)) {
                        pr_err("error: verify failed at %#llx\n",
                               (long long)addr);
                        errcnt += 1;
                }
        }
        /* Check boundary between eraseblocks */
        if (addr <= addrn - pgsize - pgsize && !bbt[ebnum + 1]) {
                struct rnd_state old_state = rnd_state;

                /* Do a read to set the internal dataRAMs to different data */
                err = mtdtest_read(mtd, addr0, bufsize, twopages);
                if (err)
                        return err;
                err = mtdtest_read(mtd, addrn - bufsize, bufsize, twopages);
                if (err)
                        return err;
                memset(twopages, 0, bufsize);
                err = mtdtest_read(mtd, addr, bufsize, twopages);
                if (err)
                        return err;
                memcpy(boundary, writebuf + mtd->erasesize - pgsize, pgsize);
                prandom_bytes_state(&rnd_state, boundary + pgsize, pgsize);
                if (memcmp(twopages, boundary, bufsize)) {
                        pr_err("error: verify failed at %#llx\n",
                               (long long)addr);
                        errcnt += 1;
                }
                rnd_state = old_state;
        }
        return err;
}

static int crosstest(void)
{
        int err = 0, i;
        loff_t addr, addr0, addrn;
        unsigned char *pp1, *pp2, *pp3, *pp4;

        pr_info("crosstest\n");
        pp1 = kcalloc(pgsize, 4, GFP_KERNEL);
        if (!pp1)
                return -ENOMEM;
        pp2 = pp1 + pgsize;
        pp3 = pp2 + pgsize;
        pp4 = pp3 + pgsize;

        addr0 = 0;
        for (i = 0; i < ebcnt && bbt[i]; ++i)
                addr0 += mtd->erasesize;

        addrn = mtd->size;
        for (i = 0; i < ebcnt && bbt[ebcnt - i - 1]; ++i)
                addrn -= mtd->erasesize;

        /* Read 2nd-to-last page to pp1 */
        addr = addrn - pgsize - pgsize;
        err = mtdtest_read(mtd, addr, pgsize, pp1);
        if (err) {
                kfree(pp1);
                return err;
        }

        /* Read 3rd-to-last page to pp1 */
        addr = addrn - pgsize - pgsize - pgsize;
        err = mtdtest_read(mtd, addr, pgsize, pp1);
        if (err) {
                kfree(pp1);
                return err;
        }

        /* Read first page to pp2 */
        addr = addr0;
        pr_info("reading page at %#llx\n", (long long)addr);
        err = mtdtest_read(mtd, addr, pgsize, pp2);
        if (err) {
                kfree(pp1);
                return err;
        }

        /* Read last page to pp3 */
        addr = addrn - pgsize;
        pr_info("reading page at %#llx\n", (long long)addr);
        err = mtdtest_read(mtd, addr, pgsize, pp3);
        if (err) {
                kfree(pp1);
                return err;
        }

        /* Read first page again to pp4 */
        addr = addr0;
        pr_info("reading page at %#llx\n", (long long)addr);
        err = mtdtest_read(mtd, addr, pgsize, pp4);
        if (err) {
                kfree(pp1);
                return err;
        }

        /* pp2 and pp4 should be the same */
        pr_info("verifying pages read at %#llx match\n",
               (long long)addr0);
        if (memcmp(pp2, pp4, pgsize)) {
                pr_err("verify failed!\n");
                errcnt += 1;
        } else if (!err)
                pr_info("crosstest ok\n");
        kfree(pp1);
        return err;
}

static int erasecrosstest(void)
{
        int err = 0, i, ebnum, ebnum2;
        loff_t addr0;
        char *readbuf = twopages;

        pr_info("erasecrosstest\n");

        ebnum = 0;
        addr0 = 0;
        for (i = 0; i < ebcnt && bbt[i]; ++i) {
                addr0 += mtd->erasesize;
                ebnum += 1;
        }

        ebnum2 = ebcnt - 1;
        while (ebnum2 && bbt[ebnum2])
                ebnum2 -= 1;

        pr_info("erasing block %d\n", ebnum);
        err = mtdtest_erase_eraseblock(mtd, ebnum);
        if (err)
                return err;

        pr_info("writing 1st page of block %d\n", ebnum);
        prandom_bytes_state(&rnd_state, writebuf, pgsize);
        strcpy(writebuf, "There is no data like this!");
        err = mtdtest_write(mtd, addr0, pgsize, writebuf);
        if (err)
                return err;

        pr_info("reading 1st page of block %d\n", ebnum);
        memset(readbuf, 0, pgsize);
        err = mtdtest_read(mtd, addr0, pgsize, readbuf);
        if (err)
                return err;

        pr_info("verifying 1st page of block %d\n", ebnum);
        if (memcmp(writebuf, readbuf, pgsize)) {
                pr_err("verify failed!\n");
                errcnt += 1;
                return -1;
        }

        pr_info("erasing block %d\n", ebnum);
        err = mtdtest_erase_eraseblock(mtd, ebnum);
        if (err)
                return err;

        pr_info("writing 1st page of block %d\n", ebnum);
        prandom_bytes_state(&rnd_state, writebuf, pgsize);
        strcpy(writebuf, "There is no data like this!");
        err = mtdtest_write(mtd, addr0, pgsize, writebuf);
        if (err)
                return err;

        pr_info("erasing block %d\n", ebnum2);
        err = mtdtest_erase_eraseblock(mtd, ebnum2);
        if (err)
                return err;

        pr_info("reading 1st page of block %d\n", ebnum);
        memset(readbuf, 0, pgsize);
        err = mtdtest_read(mtd, addr0, pgsize, readbuf);
        if (err)
                return err;

        pr_info("verifying 1st page of block %d\n", ebnum);
        if (memcmp(writebuf, readbuf, pgsize)) {
                pr_err("verify failed!\n");
                errcnt += 1;
                return -1;
        }

        if (!err)
                pr_info("erasecrosstest ok\n");
        return err;
}

static int erasetest(void)
{
        int err = 0, i, ebnum, ok = 1;
        loff_t addr0;

        pr_info("erasetest\n");

        ebnum = 0;
        addr0 = 0;
        for (i = 0; i < ebcnt && bbt[i]; ++i) {
                addr0 += mtd->erasesize;
                ebnum += 1;
        }

        pr_info("erasing block %d\n", ebnum);
        err = mtdtest_erase_eraseblock(mtd, ebnum);
        if (err)
                return err;

        pr_info("writing 1st page of block %d\n", ebnum);
        prandom_bytes_state(&rnd_state, writebuf, pgsize);
        err = mtdtest_write(mtd, addr0, pgsize, writebuf);
        if (err)
                return err;

        pr_info("erasing block %d\n", ebnum);
        err = mtdtest_erase_eraseblock(mtd, ebnum);
        if (err)
                return err;

        pr_info("reading 1st page of block %d\n", ebnum);
        err = mtdtest_read(mtd, addr0, pgsize, twopages);
        if (err)
                return err;

        pr_info("verifying 1st page of block %d is all 0xff\n",
               ebnum);
        for (i = 0; i < pgsize; ++i)
                if (twopages[i] != 0xff) {
                        pr_err("verifying all 0xff failed at %d\n",
                               i);
                        errcnt += 1;
                        ok = 0;
                        break;
                }

        if (ok && !err)
                pr_info("erasetest ok\n");

        return err;
}

static int __init mtd_pagetest_init(void)
{
        int err = 0;
        uint64_t tmp;
        uint32_t i;

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

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

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

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

        if (!mtd_type_is_nand(mtd)) {
                pr_info("this test requires NAND flash\n");
                goto out;
        }

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

        pr_info("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;
        bufsize = pgsize * 2;
        writebuf = kmalloc(mtd->erasesize, GFP_KERNEL);
        if (!writebuf)
                goto out;
        twopages = kmalloc(bufsize, GFP_KERNEL);
        if (!twopages)
                goto out;
        boundary = kmalloc(bufsize, GFP_KERNEL);
        if (!boundary)
                goto out;

        bbt = kzalloc(ebcnt, GFP_KERNEL);
        if (!bbt)
                goto out;
        err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt);
        if (err)
                goto out;

        /* Erase all eraseblocks */
        pr_info("erasing whole device\n");
        err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
        if (err)
                goto out;
        pr_info("erased %u eraseblocks\n", ebcnt);

        /* Write all eraseblocks */
        prandom_seed_state(&rnd_state, 1);
        pr_info("writing whole device\n");
        for (i = 0; i < ebcnt; ++i) {
                if (bbt[i])
                        continue;
                err = write_eraseblock(i);
                if (err)
                        goto out;
                if (i % 256 == 0)
                        pr_info("written up to eraseblock %u\n", i);

                err = mtdtest_relax();
                if (err)
                        goto out;
        }
        pr_info("written %u eraseblocks\n", i);

        /* Check all eraseblocks */
        prandom_seed_state(&rnd_state, 1);
        pr_info("verifying all eraseblocks\n");
        for (i = 0; i < ebcnt; ++i) {
                if (bbt[i])
                        continue;
                err = verify_eraseblock(i);
                if (err)
                        goto out;
                if (i % 256 == 0)
                        pr_info("verified up to eraseblock %u\n", i);

                err = mtdtest_relax();
                if (err)
                        goto out;
        }
        pr_info("verified %u eraseblocks\n", i);

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

        if (ebcnt > 1) {
                err = erasecrosstest();
                if (err)
                        goto out;
        } else {
                pr_info("skipping erasecrosstest, 2 erase blocks needed\n");
        }

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

        pr_info("finished with %d errors\n", errcnt);
out:

        kfree(bbt);
        kfree(boundary);
        kfree(twopages);
        kfree(writebuf);
        put_mtd_device(mtd);
        if (err)
                pr_info("error %d occurred\n", err);
        printk(KERN_INFO "=================================================\n");
        return err;
}
module_init(mtd_pagetest_init);

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

MODULE_DESCRIPTION("NAND page test");
MODULE_AUTHOR("Adrian Hunter");
MODULE_LICENSE("GPL");