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/*
* MTD Oops/Panic logger
*
* Copyright © 2007 Nokia Corporation. All rights reserved.
*
* Author: Richard Purdie <rpurdie@openedhand.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#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 void mtdoops_erase_callback(struct erase_info *done)
{
wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
wake_up(wait_q);
}
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;
DECLARE_WAITQUEUE(wait, current);
wait_queue_head_t wait_q;
int ret;
int page;
init_waitqueue_head(&wait_q);
erase.mtd = mtd;
erase.callback = mtdoops_erase_callback;
erase.addr = offset;
erase.len = mtd->erasesize;
erase.priv = (u_long)&wait_q;
set_current_state(TASK_INTERRUPTIBLE);
add_wait_queue(&wait_q, &wait);
ret = mtd->erase(mtd, &erase);
if (ret) {
set_current_state(TASK_RUNNING);
remove_wait_queue(&wait_q, &wait);
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;
}
schedule(); /* Wait for erase to finish. */
remove_wait_queue(&wait_q, &wait);
/* 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 (mtd->block_isbad) {
ret = mtd->block_isbad(mtd, cxt->nextpage * record_size);
if (!ret)
break;
if (ret < 0) {
printk(KERN_ERR "mtdoops: block_isbad failed, aborting\n");
return;
}
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;
}
}
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 (mtd->block_markbad && ret == -EIO) {
ret = mtd->block_markbad(mtd, cxt->nextpage * record_size);
if (ret < 0) {
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);
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++) {
/* 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 && ret != -EUCLEAN)) {
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)
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 = 0;
cxt->nextcount = 1;
schedule_work(&cxt->work_erase);
return;
}
cxt->nextpage = maxpos;
cxt->nextcount = maxcount;
mtdoops_inc_counter(cxt);
}
static void mtdoops_do_dump(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
const char *s2, unsigned long l2)
{
struct mtdoops_context *cxt = container_of(dumper,
struct mtdoops_context, dump);
unsigned long s1_start, s2_start;
unsigned long l1_cpy, l2_cpy;
char *dst;
if (reason != KMSG_DUMP_OOPS &&
reason != KMSG_DUMP_PANIC &&
reason != KMSG_DUMP_KEXEC)
return;
/* Only dump oopses if dump_oops is set */
if (reason == KMSG_DUMP_OOPS && !dump_oops)
return;
dst = cxt->oops_buf + MTDOOPS_HEADER_SIZE; /* Skip the header */
l2_cpy = min(l2, record_size - MTDOOPS_HEADER_SIZE);
l1_cpy = min(l1, record_size - MTDOOPS_HEADER_SIZE - l2_cpy);
s2_start = l2 - l2_cpy;
s1_start = l1 - l1_cpy;
memcpy(dst, s1 + s1_start, l1_cpy);
memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
/* Panics must be written immediately */
if (reason != KMSG_DUMP_OOPS) {
if (!cxt->mtd->panic_write)
printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n");
else
mtdoops_write(cxt, 1);
return;
}
/* 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(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.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_sync(&cxt->work_erase);
flush_work_sync(&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");
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