linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * MTD Oops/Panic logger

 *

 * Copyright © 2007 Nokia Corporation. All rights reserved.

 *

 * Author: Richard Purdie <rpurdie@openedhand.com>

 */

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/console.h>

#include <linux/vmalloc.h>

#include <linux/workqueue.h>

#include <linux/sched.h>

#include <linux/wait.h>

#include <linux/delay.h>

#include <linux/interrupt.h>

#include <linux/mtd/mtd.h>

#include <linux/kmsg_dump.h>

​

/* Maximum MTD partition size */

#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)

​

#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00

#define MTDOOPS_HEADER_SIZE   8

​

static unsigned long record_size = 4096;

module_param(record_size, ulong, 0400);

MODULE_PARM_DESC(record_size,

        "record size for MTD OOPS pages in bytes (default 4096)");

​

static char mtddev[80];

module_param_string(mtddev, mtddev, 80, 0400);

MODULE_PARM_DESC(mtddev,

        "name or index number of the MTD device to use");

​

static int dump_oops = 1;

module_param(dump_oops, int, 0600);

MODULE_PARM_DESC(dump_oops,

        "set to 1 to dump oopses, 0 to only dump panics (default 1)");

​

static struct mtdoops_context {

    struct kmsg_dumper dump;

​

    int mtd_index;

    struct work_struct work_erase;

    struct work_struct work_write;

    struct mtd_info *mtd;

    int oops_pages;

    int nextpage;

    int nextcount;

    unsigned long *oops_page_used;

​

    void *oops_buf;

} oops_cxt;

​

static void mark_page_used(struct mtdoops_context *cxt, int page)

{

    set_bit(page, cxt->oops_page_used);

}

​

static void mark_page_unused(struct mtdoops_context *cxt, int page)

{

    clear_bit(page, cxt->oops_page_used);

}

​

static int page_is_used(struct mtdoops_context *cxt, int page)

{

    return test_bit(page, cxt->oops_page_used);

}

​

static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset)

{

    struct mtd_info *mtd = cxt->mtd;

    u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize;

    u32 start_page = start_page_offset / record_size;

    u32 erase_pages = mtd->erasesize / record_size;

    struct erase_info erase;

    int ret;

    int page;

​

    erase.addr = offset;

    erase.len = mtd->erasesize;

​

    ret = mtd_erase(mtd, &erase);

    if (ret) {

        printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n",

               (unsigned long long)erase.addr,

               (unsigned long long)erase.len, mtddev);

        return ret;

    }