Orange Pi5 kernel

// 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;
<------>}
 
<------>/* Mark pages as unused */
<------>for (page = start_page; page < start_page + erase_pages; page++)
<------><------>mark_page_unused(cxt, page);
 
<------>return 0;
}
 
static void mtdoops_inc_counter(struct mtdoops_context *cxt)
{
<------>cxt->nextpage++;
<------>if (cxt->nextpage >= cxt->oops_pages)
<------><------>cxt->nextpage = 0;
<------>cxt->nextcount++;
<------>if (cxt->nextcount == 0xffffffff)
<------><------>cxt->nextcount = 0;
 
<------>if (page_is_used(cxt, cxt->nextpage)) {
<------><------>schedule_work(&cxt->work_erase);
<------><------>return;
<------>}
 
<------>printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n",
<------>       cxt->nextpage, cxt->nextcount);
}
 
/* Scheduled work - when we can't proceed without erasing a block */
static void mtdoops_workfunc_erase(struct work_struct *work)
{
<------>struct mtdoops_context *cxt =
<------><------><------>container_of(work, struct mtdoops_context, work_erase);
<------>struct mtd_info *mtd = cxt->mtd;
<------>int i = 0, j, ret, mod;
 
<------>/* We were unregistered */
<------>if (!mtd)
<------><------>return;
 
<------>mod = (cxt->nextpage * record_size) % mtd->erasesize;
<------>if (mod != 0) {
<------><------>cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size);
<------><------>if (cxt->nextpage >= cxt->oops_pages)
<------><------><------>cxt->nextpage = 0;
<------>}
 
<------>while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) {
badblock:
<------><------>printk(KERN_WARNING "mtdoops: bad block at %08lx\n",
<------><------>       cxt->nextpage * record_size);
<------><------>i++;
<------><------>cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size);
<------><------>if (cxt->nextpage >= cxt->oops_pages)
<------><------><------>cxt->nextpage = 0;
<------><------>if (i == cxt->oops_pages / (mtd->erasesize / record_size)) {
<------><------><------>printk(KERN_ERR "mtdoops: all blocks bad!\n");
<------><------><------>return;
<------><------>}
<------>}
 
<------>if (ret < 0) {
<------><------>printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n");
<------><------>return;
<------>}
 
<------>for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
<------><------>ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size);
 
<------>if (ret >= 0) {
<------><------>printk(KERN_DEBUG "mtdoops: ready %d, %d\n",
<------><------>       cxt->nextpage, cxt->nextcount);
<------><------>return;
<------>}
 
<------>if (ret == -EIO) {
<------><------>ret = mtd_block_markbad(mtd, cxt->nextpage * record_size);
<------><------>if (ret < 0 && ret != -EOPNOTSUPP) {
<------><------><------>printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n");
<------><------><------>return;
<------><------>}
<------>}
<------>goto badblock;
}
 
static void mtdoops_write(struct mtdoops_context *cxt, int panic)
{
<------>struct mtd_info *mtd = cxt->mtd;
<------>size_t retlen;
<------>u32 *hdr;
<------>int ret;
 
<------>/* Add mtdoops header to the buffer */
<------>hdr = cxt->oops_buf;
<------>hdr[0] = cxt->nextcount;
<------>hdr[1] = MTDOOPS_KERNMSG_MAGIC;
 
<------>if (panic) {
<------><------>ret = mtd_panic_write(mtd, cxt->nextpage * record_size,
<------><------><------><------>      record_size, &retlen, cxt->oops_buf);
<------><------>if (ret == -EOPNOTSUPP) {
<------><------><------>printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n");
<------><------><------>return;
<------><------>}
<------>} else
<------><------>ret = mtd_write(mtd, cxt->nextpage * record_size,
<------><------><------><------>record_size, &retlen, cxt->oops_buf);
 
<------>if (retlen != record_size || ret < 0)
<------><------>printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n",
<------><------>       cxt->nextpage * record_size, retlen, record_size, ret);
<------>mark_page_used(cxt, cxt->nextpage);
<------>memset(cxt->oops_buf, 0xff, record_size);
 
<------>mtdoops_inc_counter(cxt);
}
 
static void mtdoops_workfunc_write(struct work_struct *work)
{
<------>struct mtdoops_context *cxt =
<------><------><------>container_of(work, struct mtdoops_context, work_write);
 
<------>mtdoops_write(cxt, 0);
}
 
static void find_next_position(struct mtdoops_context *cxt)
{
<------>struct mtd_info *mtd = cxt->mtd;
<------>int ret, page, maxpos = 0;
<------>u32 count[2], maxcount = 0xffffffff;
<------>size_t retlen;
 
<------>for (page = 0; page < cxt->oops_pages; page++) {
<------><------>if (mtd_block_isbad(mtd, page * record_size))
<------><------><------>continue;
<------><------>/* Assume the page is used */
<------><------>mark_page_used(cxt, page);
<------><------>ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,
<------><------><------>       &retlen, (u_char *)&count[0]);
<------><------>if (retlen != MTDOOPS_HEADER_SIZE ||
<------><------><------><------>(ret < 0 && !mtd_is_bitflip(ret))) {
<------><------><------>printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n",
<------><------><------>       page * record_size, retlen,
<------><------><------>       MTDOOPS_HEADER_SIZE, ret);
<------><------><------>continue;
<------><------>}
 
<------><------>if (count[0] == 0xffffffff && count[1] == 0xffffffff)
<------><------><------>mark_page_unused(cxt, page);
<------><------>if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC)
<------><------><------>continue;
<------><------>if (maxcount == 0xffffffff) {
<------><------><------>maxcount = count[0];
<------><------><------>maxpos = page;
<------><------>} else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {
<------><------><------>maxcount = count[0];
<------><------><------>maxpos = page;
<------><------>} else if (count[0] > maxcount && count[0] < 0xc0000000) {
<------><------><------>maxcount = count[0];
<------><------><------>maxpos = page;
<------><------>} else if (count[0] > maxcount && count[0] > 0xc0000000
<------><------><------><------><------>&& maxcount > 0x80000000) {
<------><------><------>maxcount = count[0];
<------><------><------>maxpos = page;
<------><------>}
<------>}
<------>if (maxcount == 0xffffffff) {
<------><------>cxt->nextpage = cxt->oops_pages - 1;
<------><------>cxt->nextcount = 0;
<------>}
<------>else {
<------><------>cxt->nextpage = maxpos;
<------><------>cxt->nextcount = maxcount;
<------>}
 
<------>mtdoops_inc_counter(cxt);
}
 
static void mtdoops_do_dump(struct kmsg_dumper *dumper,
<------><------><------>    enum kmsg_dump_reason reason)
{
<------>struct mtdoops_context *cxt = container_of(dumper,
<------><------><------>struct mtdoops_context, dump);
 
<------>/* Only dump oopses if dump_oops is set */
<------>if (reason == KMSG_DUMP_OOPS && !dump_oops)
<------><------>return;
 
<------>kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE,
<------><------><------>     record_size - MTDOOPS_HEADER_SIZE, NULL);
 
<------>if (reason != KMSG_DUMP_OOPS) {
<------><------>/* Panics must be written immediately */
<------><------>mtdoops_write(cxt, 1);
<------>} else {
<------><------>/* For other cases, schedule work to write it "nicely" */
<------><------>schedule_work(&cxt->work_write);
<------>}
}
 
static void mtdoops_notify_add(struct mtd_info *mtd)
{
<------>struct mtdoops_context *cxt = &oops_cxt;
<------>u64 mtdoops_pages = div_u64(mtd->size, record_size);
<------>int err;
 
<------>if (!strcmp(mtd->name, mtddev))
<------><------>cxt->mtd_index = mtd->index;
 
<------>if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
<------><------>return;
 
<------>if (mtd->size < mtd->erasesize * 2) {
<------><------>printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n",
<------><------>       mtd->index);
<------><------>return;
<------>}
<------>if (mtd->erasesize < record_size) {
<------><------>printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n",
<------><------>       mtd->index);
<------><------>return;
<------>}
<------>if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
<------><------>printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
<------><------>       mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
<------><------>return;
<------>}
 
<------>/* oops_page_used is a bit field */
<------>cxt->oops_page_used =
<------><------>vmalloc(array_size(sizeof(unsigned long),
<------><------><------><------>   DIV_ROUND_UP(mtdoops_pages,
<------><------><------><------><------><------>BITS_PER_LONG)));
<------>if (!cxt->oops_page_used) {
<------><------>printk(KERN_ERR "mtdoops: could not allocate page array\n");
<------><------>return;
<------>}
 
<------>cxt->dump.max_reason = KMSG_DUMP_OOPS;
<------>cxt->dump.dump = mtdoops_do_dump;
<------>err = kmsg_dump_register(&cxt->dump);
<------>if (err) {
<------><------>printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err);
<------><------>vfree(cxt->oops_page_used);
<------><------>cxt->oops_page_used = NULL;
<------><------>return;
<------>}
 
<------>cxt->mtd = mtd;
<------>cxt->oops_pages = (int)mtd->size / record_size;
<------>find_next_position(cxt);
<------>printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
}
 
static void mtdoops_notify_remove(struct mtd_info *mtd)
{
<------>struct mtdoops_context *cxt = &oops_cxt;
 
<------>if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
<------><------>return;
 
<------>if (kmsg_dump_unregister(&cxt->dump) < 0)
<------><------>printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n");
 
<------>cxt->mtd = NULL;
<------>flush_work(&cxt->work_erase);
<------>flush_work(&cxt->work_write);
}
 
 
static struct mtd_notifier mtdoops_notifier = {
<------>.add	= mtdoops_notify_add,
<------>.remove	= mtdoops_notify_remove,
};
 
static int __init mtdoops_init(void)
{
<------>struct mtdoops_context *cxt = &oops_cxt;
<------>int mtd_index;
<------>char *endp;
 
<------>if (strlen(mtddev) == 0) {
<------><------>printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n");
<------><------>return -EINVAL;
<------>}
<------>if ((record_size & 4095) != 0) {
<------><------>printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n");
<------><------>return -EINVAL;
<------>}
<------>if (record_size < 4096) {
<------><------>printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n");
<------><------>return -EINVAL;
<------>}
 
<------>/* Setup the MTD device to use */
<------>cxt->mtd_index = -1;
<------>mtd_index = simple_strtoul(mtddev, &endp, 0);
<------>if (*endp == '\0')
<------><------>cxt->mtd_index = mtd_index;
 
<------>cxt->oops_buf = vmalloc(record_size);
<------>if (!cxt->oops_buf) {
<------><------>printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n");
<------><------>return -ENOMEM;
<------>}
<------>memset(cxt->oops_buf, 0xff, record_size);
 
<------>INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
<------>INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
 
<------>register_mtd_user(&mtdoops_notifier);
<------>return 0;
}
 
static void __exit mtdoops_exit(void)
{
<------>struct mtdoops_context *cxt = &oops_cxt;
 
<------>unregister_mtd_user(&mtdoops_notifier);
<------>vfree(cxt->oops_buf);
<------>vfree(cxt->oops_page_used);
}
 
 
module_init(mtdoops_init);
module_exit(mtdoops_exit);
 
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");