root/drivers/mtd/tests/subpagetest.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2006-2007 Nokia Corporation
 *
 * Test sub-page read and write on MTD device.
 * Author: Adrian Hunter <ext-adrian.hunter@nokia.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 *writebuf;
static unsigned char *readbuf;
static unsigned char *bbt;

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

static inline void clear_data(unsigned char *buf, size_t len)
{
        memset(buf, 0, len);
}

static int write_eraseblock(int ebnum)
{
        size_t written;
        int err = 0;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;

        prandom_bytes_state(&rnd_state, writebuf, subpgsize);
        err = mtd_write(mtd, addr, subpgsize, &written, writebuf);
        if (unlikely(err || written != subpgsize)) {
                pr_err("error: write failed at %#llx\n",
                       (long long)addr);
                if (written != subpgsize) {
                        pr_err("  write size: %#x\n", subpgsize);
                        pr_err("  written: %#zx\n", written);
                }
                return err ? err : -1;
        }

        addr += subpgsize;

        prandom_bytes_state(&rnd_state, writebuf, subpgsize);
        err = mtd_write(mtd, addr, subpgsize, &written, writebuf);
        if (unlikely(err || written != subpgsize)) {
                pr_err("error: write failed at %#llx\n",
                       (long long)addr);
                if (written != subpgsize) {
                        pr_err("  write size: %#x\n", subpgsize);
                        pr_err("  written: %#zx\n", written);
                }
                return err ? err : -1;
        }

        return err;
}

static int write_eraseblock2(int ebnum)
{
        size_t written;
        int err = 0, k;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;

        for (k = 1; k < 33; ++k) {
                if (addr + (subpgsize * k) > (loff_t)(ebnum + 1) * mtd->erasesize)
                        break;
                prandom_bytes_state(&rnd_state, writebuf, subpgsize * k);
                err = mtd_write(mtd, addr, subpgsize * k, &written, writebuf);
                if (unlikely(err || written != subpgsize * k)) {
                        pr_err("error: write failed at %#llx\n",
                               (long long)addr);
                        if (written != subpgsize * k) {
                                pr_err("  write size: %#x\n",
                                       subpgsize * k);
                                pr_err("  written: %#08zx\n",
                                       written);
                        }
                        return err ? err : -1;
                }
                addr += subpgsize * k;
        }

        return err;
}

static void print_subpage(unsigned char *p)
{
        int i, j;

        for (i = 0; i < subpgsize; ) {
                for (j = 0; i < subpgsize && j < 32; ++i, ++j)
                        printk("%02x", *p++);
                printk("\n");
        }
}

static int verify_eraseblock(int ebnum)
{
        size_t read;
        int err = 0;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;

        prandom_bytes_state(&rnd_state, writebuf, subpgsize);
        clear_data(readbuf, subpgsize);
        err = mtd_read(mtd, addr, subpgsize, &read, readbuf);
        if (unlikely(err || read != subpgsize)) {
                if (mtd_is_bitflip(err) && read == subpgsize) {
                        pr_info("ECC correction at %#llx\n",
                               (long long)addr);
                        err = 0;
                } else {
                        pr_err("error: read failed at %#llx\n",
                               (long long)addr);
                        return err ? err : -1;
                }
        }
        if (unlikely(memcmp(readbuf, writebuf, subpgsize))) {
                pr_err("error: verify failed at %#llx\n",
                       (long long)addr);
                pr_info("------------- written----------------\n");
                print_subpage(writebuf);
                pr_info("------------- read ------------------\n");
                print_subpage(readbuf);
                pr_info("-------------------------------------\n");
                errcnt += 1;
        }

        addr += subpgsize;

        prandom_bytes_state(&rnd_state, writebuf, subpgsize);
        clear_data(readbuf, subpgsize);
        err = mtd_read(mtd, addr, subpgsize, &read, readbuf);
        if (unlikely(err || read != subpgsize)) {
                if (mtd_is_bitflip(err) && read == subpgsize) {
                        pr_info("ECC correction at %#llx\n",
                               (long long)addr);
                        err = 0;
                } else {
                        pr_err("error: read failed at %#llx\n",
                               (long long)addr);
                        return err ? err : -1;
                }
        }
        if (unlikely(memcmp(readbuf, writebuf, subpgsize))) {
                pr_info("error: verify failed at %#llx\n",
                       (long long)addr);
                pr_info("------------- written----------------\n");
                print_subpage(writebuf);
                pr_info("------------- read ------------------\n");
                print_subpage(readbuf);
                pr_info("-------------------------------------\n");
                errcnt += 1;
        }

        return err;
}

static int verify_eraseblock2(int ebnum)
{
        size_t read;
        int err = 0, k;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;

        for (k = 1; k < 33; ++k) {
                if (addr + (subpgsize * k) > (loff_t)(ebnum + 1) * mtd->erasesize)
                        break;
                prandom_bytes_state(&rnd_state, writebuf, subpgsize * k);
                clear_data(readbuf, subpgsize * k);
                err = mtd_read(mtd, addr, subpgsize * k, &read, readbuf);
                if (unlikely(err || read != subpgsize * k)) {
                        if (mtd_is_bitflip(err) && read == subpgsize * k) {
                                pr_info("ECC correction at %#llx\n",
                                       (long long)addr);
                                err = 0;
                        } else {
                                pr_err("error: read failed at "
                                       "%#llx\n", (long long)addr);
                                return err ? err : -1;
                        }
                }
                if (unlikely(memcmp(readbuf, writebuf, subpgsize * k))) {
                        pr_err("error: verify failed at %#llx\n",
                               (long long)addr);
                        errcnt += 1;
                }
                addr += subpgsize * k;
        }

        return err;
}

static int verify_eraseblock_ff(int ebnum)
{
        uint32_t j;
        size_t read;
        int err = 0;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;

        memset(writebuf, 0xff, subpgsize);
        for (j = 0; j < mtd->erasesize / subpgsize; ++j) {
                clear_data(readbuf, subpgsize);
                err = mtd_read(mtd, addr, subpgsize, &read, readbuf);
                if (unlikely(err || read != subpgsize)) {
                        if (mtd_is_bitflip(err) && read == subpgsize) {
                                pr_info("ECC correction at %#llx\n",
                                       (long long)addr);
                                err = 0;
                        } else {
                                pr_err("error: read failed at "
                                       "%#llx\n", (long long)addr);
                                return err ? err : -1;
                        }
                }
                if (unlikely(memcmp(readbuf, writebuf, subpgsize))) {
                        pr_err("error: verify 0xff failed at "
                               "%#llx\n", (long long)addr);
                        errcnt += 1;
                }
                addr += subpgsize;
        }

        return err;
}

static int verify_all_eraseblocks_ff(void)
{
        int err;
        unsigned int i;

        pr_info("verifying all eraseblocks for 0xff\n");
        for (i = 0; i < ebcnt; ++i) {
                if (bbt[i])
                        continue;
                err = verify_eraseblock_ff(i);
                if (err)
                        return err;
                if (i % 256 == 0)
                        pr_info("verified up to eraseblock %u\n", i);

                err = mtdtest_relax();
                if (err)
                        return err;
        }
        pr_info("verified %u eraseblocks\n", i);
        return 0;
}

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

        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;
        }

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

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

        err = -ENOMEM;
        bufsize = subpgsize * 32;
        writebuf = kmalloc(bufsize, GFP_KERNEL);
        if (!writebuf)
                goto out;
        readbuf = kmalloc(bufsize, GFP_KERNEL);
        if (!readbuf)
                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;

        err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
        if (err)
                goto out;

        pr_info("writing whole device\n");
        prandom_seed_state(&rnd_state, 1);
        for (i = 0; i < ebcnt; ++i) {
                if (bbt[i])
                        continue;
                err = write_eraseblock(i);
                if (unlikely(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);

        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 (unlikely(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 = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
        if (err)
                goto out;

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

        /* Write all eraseblocks */
        prandom_seed_state(&rnd_state, 3);
        pr_info("writing whole device\n");
        for (i = 0; i < ebcnt; ++i) {
                if (bbt[i])
                        continue;
                err = write_eraseblock2(i);
                if (unlikely(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, 3);
        pr_info("verifying all eraseblocks\n");
        for (i = 0; i < ebcnt; ++i) {
                if (bbt[i])
                        continue;
                err = verify_eraseblock2(i);
                if (unlikely(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 = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
        if (err)
                goto out;

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

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

out:
        kfree(bbt);
        kfree(readbuf);
        kfree(writebuf);
        put_mtd_device(mtd);
        if (err)
                pr_info("error %d occurred\n", err);
        printk(KERN_INFO "=================================================\n");
        return err;
}
module_init(mtd_subpagetest_init);

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

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