// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2006-2008 Nokia Corporation
 *
 * Check MTD device read.
 *
 * 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 "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 *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)
{
        int i, ret, err = 0;
        loff_t addr = (loff_t)ebnum * mtd->erasesize;
        void *buf = iobuf;
        void *oobbuf = iobuf1;

        for (i = 0; i < pgcnt; i++) {
                memset(buf, 0 , pgsize);
                ret = mtdtest_read(mtd, addr, pgsize, buf);
                if (ret) {
                        if (!err)
                                err = ret;
                }
                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) {
                                pr_err("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;

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

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

        if (dev < 0) {
                pr_info("Please specify a valid mtd-device via module parameter\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->writesize == 1) {
                pr_info("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;

        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;
        iobuf = kmalloc(mtd->erasesize, GFP_KERNEL);
        if (!iobuf)
                goto out;
        iobuf1 = kmalloc(mtd->erasesize, GFP_KERNEL);
        if (!iobuf1)
                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;

        /* Read all eraseblocks 1 page at a time */
        pr_info("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;
                }

                ret = mtdtest_relax();
                if (ret) {
                        err = ret;
                        goto out;
                }
        }

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

out:

        kfree(iobuf);
        kfree(iobuf1);
        kfree(bbt);
        put_mtd_device(mtd);
        if (err)
                pr_info("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");