/* * 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 ((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); 	/* 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(&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");