[deliverable/linux.git] / drivers / mtd / mtdoops.c

/*
 * 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 (1) {
		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 (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)
			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)
{
	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);

	/* Panics must be written immediately */
	if (reason != KMSG_DUMP_OOPS)
		mtdoops_write(cxt, 1);

	/* 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) * sizeof(unsigned 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_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");
Commit	Line	Data
4b23aff0 RP	1	/*
	2	* MTD Oops/Panic logger
	3	*
a1452a37	4	* Copyright © 2007 Nokia Corporation. All rights reserved.
4b23aff0 RP	5	*
	6	* Author: Richard Purdie <rpurdie@openedhand.com>
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* version 2 as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	15	* General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	20	* 02110-1301 USA
	21	*
	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/module.h>
	26	#include <linux/console.h>
	27	#include <linux/vmalloc.h>
	28	#include <linux/workqueue.h>
	29	#include <linux/sched.h>
	30	#include <linux/wait.h>
621e4f8e	31	#include <linux/delay.h>
f9f7dd22	32	#include <linux/interrupt.h>
4b23aff0	33	#include <linux/mtd/mtd.h>
2e386e4b	34	#include <linux/kmsg_dump.h>
4b23aff0	35
1114e3d0 SK	36	/* Maximum MTD partition size */
	37	#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)
	38
f0482ee3	39	#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00
2e386e4b	40	#define MTDOOPS_HEADER_SIZE 8
9507b0c8 SK	41
	42	static unsigned long record_size = 4096;
	43	module_param(record_size, ulong, 0400);
	44	MODULE_PARM_DESC(record_size,
	45	"record size for MTD OOPS pages in bytes (default 4096)");
4b23aff0	46
2e386e4b SK	47	static char mtddev[80];
	48	module_param_string(mtddev, mtddev, 80, 0400);
	49	MODULE_PARM_DESC(mtddev,
	50	"name or index number of the MTD device to use");
	51
	52	static int dump_oops = 1;
	53	module_param(dump_oops, int, 0600);
	54	MODULE_PARM_DESC(dump_oops,
	55	"set to 1 to dump oopses, 0 to only dump panics (default 1)");
	56
7903cbab	57	static struct mtdoops_context {
2e386e4b SK	58	struct kmsg_dumper dump;
2e386e4b SK	59
4b23aff0	60	int mtd_index;
6ce0a856 RP	61	struct work_struct work_erase;
6ce0a856 RP	62	struct work_struct work_write;
4b23aff0 RP	63	struct mtd_info *mtd;
	64	int oops_pages;
	65	int nextpage;
	66	int nextcount;
be95745f	67	unsigned long *oops_page_used;
4b23aff0 RP	68
4b23aff0 RP	69	void *oops_buf;
4b23aff0 RP	70	} oops_cxt;
4b23aff0 RP	71
be95745f SK	72	static void mark_page_used(struct mtdoops_context *cxt, int page)
	73	{
	74	set_bit(page, cxt->oops_page_used);
	75	}
	76
	77	static void mark_page_unused(struct mtdoops_context *cxt, int page)
	78	{
	79	clear_bit(page, cxt->oops_page_used);
	80	}
	81
	82	static int page_is_used(struct mtdoops_context *cxt, int page)
	83	{
	84	return test_bit(page, cxt->oops_page_used);
	85	}
	86
4b23aff0 RP	87	static void mtdoops_erase_callback(struct erase_info *done)
	88	{
	89	wait_queue_head_t wait_q = (wait_queue_head_t )done->priv;
	90	wake_up(wait_q);
	91	}
	92
be95745f	93	static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset)
4b23aff0	94	{
be95745f SK	95	struct mtd_info *mtd = cxt->mtd;
be95745f SK	96	u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize;
9507b0c8 SK	97	u32 start_page = start_page_offset / record_size;
9507b0c8 SK	98	u32 erase_pages = mtd->erasesize / record_size;
4b23aff0 RP	99	struct erase_info erase;
	100	DECLARE_WAITQUEUE(wait, current);
	101	wait_queue_head_t wait_q;
	102	int ret;
be95745f	103	int page;
4b23aff0 RP	104
	105	init_waitqueue_head(&wait_q);
	106	erase.mtd = mtd;
	107	erase.callback = mtdoops_erase_callback;
	108	erase.addr = offset;
79dcd8e9	109	erase.len = mtd->erasesize;
4b23aff0 RP	110	erase.priv = (u_long)&wait_q;
	111
	112	set_current_state(TASK_INTERRUPTIBLE);
	113	add_wait_queue(&wait_q, &wait);
	114
7e1f0dc0	115	ret = mtd_erase(mtd, &erase);
4b23aff0 RP	116	if (ret) {
	117	set_current_state(TASK_RUNNING);
	118	remove_wait_queue(&wait_q, &wait);
a15b124f AB	119	printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n",
a15b124f AB	120	(unsigned long long)erase.addr,
2e386e4b	121	(unsigned long long)erase.len, mtddev);
4b23aff0 RP	122	return ret;
	123	}
	124
	125	schedule(); /* Wait for erase to finish. */
	126	remove_wait_queue(&wait_q, &wait);
	127
be95745f SK	128	/* Mark pages as unused */
	129	for (page = start_page; page < start_page + erase_pages; page++)
	130	mark_page_unused(cxt, page);
	131
4b23aff0 RP	132	return 0;
	133	}
	134
6ce0a856	135	static void mtdoops_inc_counter(struct mtdoops_context *cxt)
4b23aff0	136	{
4b23aff0	137	cxt->nextpage++;
ecd5b310	138	if (cxt->nextpage >= cxt->oops_pages)
4b23aff0 RP	139	cxt->nextpage = 0;
	140	cxt->nextcount++;
	141	if (cxt->nextcount == 0xffffffff)
	142	cxt->nextcount = 0;
	143
be95745f	144	if (page_is_used(cxt, cxt->nextpage)) {
6ce0a856 RP	145	schedule_work(&cxt->work_erase);
	146	return;
	147	}
4b23aff0	148
a15b124f AB	149	printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n",
a15b124f AB	150	cxt->nextpage, cxt->nextcount);
4b23aff0 RP	151	}
4b23aff0 RP	152
6ce0a856 RP	153	/* Scheduled work - when we can't proceed without erasing a block */
6ce0a856 RP	154	static void mtdoops_workfunc_erase(struct work_struct *work)
4b23aff0	155	{
6ce0a856 RP	156	struct mtdoops_context *cxt =
6ce0a856 RP	157	container_of(work, struct mtdoops_context, work_erase);
4b23aff0 RP	158	struct mtd_info *mtd = cxt->mtd;
	159	int i = 0, j, ret, mod;
	160
	161	/* We were unregistered */
	162	if (!mtd)
	163	return;
	164
9507b0c8	165	mod = (cxt->nextpage * record_size) % mtd->erasesize;
4b23aff0	166	if (mod != 0) {
9507b0c8	167	cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size);
ecd5b310	168	if (cxt->nextpage >= cxt->oops_pages)
4b23aff0 RP	169	cxt->nextpage = 0;
	170	}
	171
bb4a0986	172	while (1) {
7086c19d	173	ret = mtd_block_isbad(mtd, cxt->nextpage * record_size);
2986bd2a RP	174	if (!ret)
	175	break;
	176	if (ret < 0) {
a15b124f	177	printk(KERN_ERR "mtdoops: block_isbad failed, aborting\n");
2986bd2a RP	178	return;
2986bd2a RP	179	}
4b23aff0	180	badblock:
9507b0c8 SK	181	printk(KERN_WARNING "mtdoops: bad block at %08lx\n",
9507b0c8 SK	182	cxt->nextpage * record_size);
4b23aff0	183	i++;
9507b0c8	184	cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size);
ecd5b310	185	if (cxt->nextpage >= cxt->oops_pages)
4b23aff0	186	cxt->nextpage = 0;
9507b0c8	187	if (i == cxt->oops_pages / (mtd->erasesize / record_size)) {
a15b124f	188	printk(KERN_ERR "mtdoops: all blocks bad!\n");
4b23aff0 RP	189	return;
	190	}
	191	}
	192
	193	for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
9507b0c8	194	ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size);
4b23aff0	195
2986bd2a	196	if (ret >= 0) {
a15b124f AB	197	printk(KERN_DEBUG "mtdoops: ready %d, %d\n",
a15b124f AB	198	cxt->nextpage, cxt->nextcount);
2986bd2a	199	return;
4b23aff0 RP	200	}
4b23aff0 RP	201
bb4a0986	202	if (ret == -EIO) {
5942ddbc	203	ret = mtd_block_markbad(mtd, cxt->nextpage * record_size);
bb4a0986	204	if (ret < 0 && ret != -EOPNOTSUPP) {
a15b124f	205	printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n");
2986bd2a RP	206	return;
	207	}
	208	}
	209	goto badblock;
4b23aff0 RP	210	}
4b23aff0 RP	211
621e4f8e	212	static void mtdoops_write(struct mtdoops_context *cxt, int panic)
4b23aff0	213	{
6ce0a856 RP	214	struct mtd_info *mtd = cxt->mtd;
6ce0a856 RP	215	size_t retlen;
2e386e4b	216	u32 *hdr;
6ce0a856	217	int ret;
4b23aff0	218
2e386e4b SK	219	/* Add mtdoops header to the buffer */
	220	hdr = cxt->oops_buf;
	221	hdr[0] = cxt->nextcount;
	222	hdr[1] = MTDOOPS_KERNMSG_MAGIC;
6ce0a856	223
016c1291	224	if (panic) {
7ae79d7f AB	225	ret = mtd_panic_write(mtd, cxt->nextpage * record_size,
7ae79d7f AB	226	record_size, &retlen, cxt->oops_buf);
016c1291 AB	227	if (ret == -EOPNOTSUPP) {
	228	printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n");
	229	return;
	230	}
	231	} else
eda95cbf AB	232	ret = mtd_write(mtd, cxt->nextpage * record_size,
eda95cbf AB	233	record_size, &retlen, cxt->oops_buf);
6ce0a856	234
9507b0c8 SK	235	if (retlen != record_size \|\| ret < 0)
	236	printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n",
	237	cxt->nextpage * record_size, retlen, record_size, ret);
be95745f	238	mark_page_used(cxt, cxt->nextpage);
2e386e4b	239	memset(cxt->oops_buf, 0xff, record_size);
6ce0a856 RP	240
6ce0a856 RP	241	mtdoops_inc_counter(cxt);
621e4f8e RP	242	}
621e4f8e RP	243
621e4f8e RP	244	static void mtdoops_workfunc_write(struct work_struct *work)
	245	{
	246	struct mtdoops_context *cxt =
	247	container_of(work, struct mtdoops_context, work_write);
	248
	249	mtdoops_write(cxt, 0);
a15b124f	250	}
4b23aff0	251
6ce0a856	252	static void find_next_position(struct mtdoops_context *cxt)
4b23aff0 RP	253	{
4b23aff0 RP	254	struct mtd_info *mtd = cxt->mtd;
2986bd2a	255	int ret, page, maxpos = 0;
f0482ee3	256	u32 count[2], maxcount = 0xffffffff;
4b23aff0 RP	257	size_t retlen;
	258
	259	for (page = 0; page < cxt->oops_pages; page++) {
bb4a0986	260	if (mtd_block_isbad(mtd, page * record_size))
3538c563	261	continue;
be95745f SK	262	/* Assume the page is used */
be95745f SK	263	mark_page_used(cxt, page);
329ad399 AB	264	ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,
329ad399 AB	265	&retlen, (u_char *)&count[0]);
2e386e4b	266	if (retlen != MTDOOPS_HEADER_SIZE \|\|
d57f4054	267	(ret < 0 && !mtd_is_bitflip(ret))) {
2e386e4b SK	268	printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n",
	269	page * record_size, retlen,
	270	MTDOOPS_HEADER_SIZE, ret);
2986bd2a RP	271	continue;
	272	}
	273
be95745f SK	274	if (count[0] == 0xffffffff && count[1] == 0xffffffff)
be95745f SK	275	mark_page_unused(cxt, page);
f0482ee3	276	if (count[0] == 0xffffffff)
4b23aff0 RP	277	continue;
4b23aff0 RP	278	if (maxcount == 0xffffffff) {
f0482ee3	279	maxcount = count[0];
4b23aff0	280	maxpos = page;
a15b124f	281	} else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {
f0482ee3	282	maxcount = count[0];
4b23aff0	283	maxpos = page;
a15b124f	284	} else if (count[0] > maxcount && count[0] < 0xc0000000) {
f0482ee3	285	maxcount = count[0];
4b23aff0	286	maxpos = page;
a15b124f AB	287	} else if (count[0] > maxcount && count[0] > 0xc0000000
a15b124f AB	288	&& maxcount > 0x80000000) {
f0482ee3	289	maxcount = count[0];
4b23aff0 RP	290	maxpos = page;
	291	}
	292	}
	293	if (maxcount == 0xffffffff) {
	294	cxt->nextpage = 0;
	295	cxt->nextcount = 1;
43b5693d	296	schedule_work(&cxt->work_erase);
6ce0a856	297	return;
4b23aff0 RP	298	}
	299
	300	cxt->nextpage = maxpos;
	301	cxt->nextcount = maxcount;
	302
6ce0a856	303	mtdoops_inc_counter(cxt);
4b23aff0 RP	304	}
4b23aff0 RP	305
2e386e4b	306	static void mtdoops_do_dump(struct kmsg_dumper *dumper,
e2ae715d	307	enum kmsg_dump_reason reason)
2e386e4b SK	308	{
	309	struct mtdoops_context *cxt = container_of(dumper,
	310	struct mtdoops_context, dump);
fc2d557c	311
2e386e4b SK	312	/* Only dump oopses if dump_oops is set */
	313	if (reason == KMSG_DUMP_OOPS && !dump_oops)
	314	return;
	315
e2ae715d KS	316	kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE,
e2ae715d KS	317	record_size - MTDOOPS_HEADER_SIZE, NULL);
2e386e4b SK	318
2e386e4b SK	319	/* Panics must be written immediately */
016c1291 AB	320	if (reason != KMSG_DUMP_OOPS)
016c1291 AB	321	mtdoops_write(cxt, 1);
2e386e4b SK	322
	323	/* For other cases, schedule work to write it "nicely" */
	324	schedule_work(&cxt->work_write);
	325	}
4b23aff0 RP	326
	327	static void mtdoops_notify_add(struct mtd_info *mtd)
	328	{
	329	struct mtdoops_context *cxt = &oops_cxt;
2e386e4b SK	330	u64 mtdoops_pages = div_u64(mtd->size, record_size);
2e386e4b SK	331	int err;
4b23aff0	332
2e386e4b	333	if (!strcmp(mtd->name, mtddev))
e2a0f25b AH	334	cxt->mtd_index = mtd->index;
e2a0f25b AH	335
a15b124f	336	if (mtd->index != cxt->mtd_index \|\| cxt->mtd_index < 0)
4b23aff0 RP	337	return;
4b23aff0 RP	338
a15b124f AB	339	if (mtd->size < mtd->erasesize * 2) {
	340	printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n",
	341	mtd->index);
4b23aff0 RP	342	return;
4b23aff0 RP	343	}
9507b0c8	344	if (mtd->erasesize < record_size) {
a15b124f AB	345	printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n",
a15b124f AB	346	mtd->index);
79dcd8e9 RP	347	return;
79dcd8e9 RP	348	}
1114e3d0 SK	349	if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
	350	printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
	351	mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
	352	return;
	353	}
	354
be95745f SK	355	/* oops_page_used is a bit field */
be95745f SK	356	cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages,
556f0635	357	BITS_PER_LONG) * sizeof(unsigned long));
be95745f	358	if (!cxt->oops_page_used) {
2e386e4b SK	359	printk(KERN_ERR "mtdoops: could not allocate page array\n");
	360	return;
	361	}
	362
e2ae715d	363	cxt->dump.max_reason = KMSG_DUMP_OOPS;
2e386e4b SK	364	cxt->dump.dump = mtdoops_do_dump;
	365	err = kmsg_dump_register(&cxt->dump);
	366	if (err) {
	367	printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err);
	368	vfree(cxt->oops_page_used);
	369	cxt->oops_page_used = NULL;
be95745f SK	370	return;
be95745f SK	371	}
4b23aff0	372
1114e3d0	373	cxt->mtd = mtd;
9507b0c8	374	cxt->oops_pages = (int)mtd->size / record_size;
6ce0a856	375	find_next_position(cxt);
79dcd8e9	376	printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
4b23aff0 RP	377	}
	378
	379	static void mtdoops_notify_remove(struct mtd_info *mtd)
	380	{
	381	struct mtdoops_context *cxt = &oops_cxt;
	382
a15b124f	383	if (mtd->index != cxt->mtd_index \|\| cxt->mtd_index < 0)
4b23aff0 RP	384	return;
4b23aff0 RP	385
2e386e4b SK	386	if (kmsg_dump_unregister(&cxt->dump) < 0)
	387	printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n");
	388
4b23aff0	389	cxt->mtd = NULL;
75c52a49 TH	390	flush_work_sync(&cxt->work_erase);
75c52a49 TH	391	flush_work_sync(&cxt->work_write);
4b23aff0 RP	392	}
4b23aff0 RP	393
4b23aff0 RP	394
	395	static struct mtd_notifier mtdoops_notifier = {
	396	.add = mtdoops_notify_add,
	397	.remove = mtdoops_notify_remove,
	398	};
	399
2e386e4b	400	static int __init mtdoops_init(void)
4b23aff0 RP	401	{
4b23aff0 RP	402	struct mtdoops_context *cxt = &oops_cxt;
2e386e4b SK	403	int mtd_index;
2e386e4b SK	404	char *endp;
4b23aff0	405
2e386e4b SK	406	if (strlen(mtddev) == 0) {
	407	printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n");
	408	return -EINVAL;
	409	}
9507b0c8 SK	410	if ((record_size & 4095) != 0) {
	411	printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n");
	412	return -EINVAL;
	413	}
	414	if (record_size < 4096) {
	415	printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n");
	416	return -EINVAL;
	417	}
2e386e4b SK	418
2e386e4b SK	419	/* Setup the MTD device to use */
4b23aff0	420	cxt->mtd_index = -1;
2e386e4b SK	421	mtd_index = simple_strtoul(mtddev, &endp, 0);
	422	if (*endp == '\0')
	423	cxt->mtd_index = mtd_index;
2e386e4b	424
9507b0c8	425	cxt->oops_buf = vmalloc(record_size);
4b23aff0	426	if (!cxt->oops_buf) {
a15b124f	427	printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n");
4b23aff0 RP	428	return -ENOMEM;
4b23aff0 RP	429	}
2e386e4b	430	memset(cxt->oops_buf, 0xff, record_size);
4b23aff0	431
6ce0a856 RP	432	INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
6ce0a856 RP	433	INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
4b23aff0	434
4b23aff0 RP	435	register_mtd_user(&mtdoops_notifier);
	436	return 0;
	437	}
	438
2e386e4b	439	static void __exit mtdoops_exit(void)
4b23aff0 RP	440	{
	441	struct mtdoops_context *cxt = &oops_cxt;
	442
	443	unregister_mtd_user(&mtdoops_notifier);
4b23aff0	444	vfree(cxt->oops_buf);
be95745f	445	vfree(cxt->oops_page_used);
4b23aff0 RP	446	}
	447
	448
2e386e4b SK	449	module_init(mtdoops_init);
2e386e4b SK	450	module_exit(mtdoops_exit);
4b23aff0 RP	451
	452	MODULE_LICENSE("GPL");
	453	MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
	454	MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");