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![Zhen Lei](/assets/img/avatar_default.png)
Fixes scripts/checkpatch.pl warning: WARNING: Possible unnecessary 'out of memory' message Remove it can help us save a bit of memory. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20210610021201.15076-1-thunder.leizhen@huawei.com
431 lines
11 KiB
C
431 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* MTD Oops/Panic logger
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*
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* Copyright © 2007 Nokia Corporation. All rights reserved.
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*
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* Author: Richard Purdie <rpurdie@openedhand.com>
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/console.h>
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#include <linux/vmalloc.h>
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#include <linux/workqueue.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/mtd/mtd.h>
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#include <linux/kmsg_dump.h>
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/* Maximum MTD partition size */
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#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)
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#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00
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#define MTDOOPS_HEADER_SIZE 8
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static unsigned long record_size = 4096;
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module_param(record_size, ulong, 0400);
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MODULE_PARM_DESC(record_size,
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"record size for MTD OOPS pages in bytes (default 4096)");
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static char mtddev[80];
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module_param_string(mtddev, mtddev, 80, 0400);
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MODULE_PARM_DESC(mtddev,
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"name or index number of the MTD device to use");
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static int dump_oops = 1;
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module_param(dump_oops, int, 0600);
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MODULE_PARM_DESC(dump_oops,
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"set to 1 to dump oopses, 0 to only dump panics (default 1)");
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static struct mtdoops_context {
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struct kmsg_dumper dump;
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int mtd_index;
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struct work_struct work_erase;
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struct work_struct work_write;
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struct mtd_info *mtd;
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int oops_pages;
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int nextpage;
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int nextcount;
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unsigned long *oops_page_used;
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unsigned long oops_buf_busy;
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void *oops_buf;
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} oops_cxt;
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static void mark_page_used(struct mtdoops_context *cxt, int page)
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{
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set_bit(page, cxt->oops_page_used);
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}
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static void mark_page_unused(struct mtdoops_context *cxt, int page)
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{
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clear_bit(page, cxt->oops_page_used);
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}
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static int page_is_used(struct mtdoops_context *cxt, int page)
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{
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return test_bit(page, cxt->oops_page_used);
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}
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static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset)
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{
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struct mtd_info *mtd = cxt->mtd;
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u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize;
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u32 start_page = start_page_offset / record_size;
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u32 erase_pages = mtd->erasesize / record_size;
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struct erase_info erase;
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int ret;
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int page;
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erase.addr = offset;
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erase.len = mtd->erasesize;
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ret = mtd_erase(mtd, &erase);
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if (ret) {
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printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n",
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(unsigned long long)erase.addr,
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(unsigned long long)erase.len, mtddev);
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return ret;
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}
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/* Mark pages as unused */
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for (page = start_page; page < start_page + erase_pages; page++)
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mark_page_unused(cxt, page);
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return 0;
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}
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static void mtdoops_inc_counter(struct mtdoops_context *cxt)
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{
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cxt->nextpage++;
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if (cxt->nextpage >= cxt->oops_pages)
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cxt->nextpage = 0;
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cxt->nextcount++;
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if (cxt->nextcount == 0xffffffff)
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cxt->nextcount = 0;
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if (page_is_used(cxt, cxt->nextpage)) {
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schedule_work(&cxt->work_erase);
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return;
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}
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printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n",
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cxt->nextpage, cxt->nextcount);
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}
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/* Scheduled work - when we can't proceed without erasing a block */
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static void mtdoops_workfunc_erase(struct work_struct *work)
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{
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struct mtdoops_context *cxt =
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container_of(work, struct mtdoops_context, work_erase);
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struct mtd_info *mtd = cxt->mtd;
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int i = 0, j, ret, mod;
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/* We were unregistered */
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if (!mtd)
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return;
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mod = (cxt->nextpage * record_size) % mtd->erasesize;
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if (mod != 0) {
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cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size);
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if (cxt->nextpage >= cxt->oops_pages)
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cxt->nextpage = 0;
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}
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while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) {
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badblock:
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printk(KERN_WARNING "mtdoops: bad block at %08lx\n",
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cxt->nextpage * record_size);
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i++;
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cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size);
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if (cxt->nextpage >= cxt->oops_pages)
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cxt->nextpage = 0;
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if (i == cxt->oops_pages / (mtd->erasesize / record_size)) {
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printk(KERN_ERR "mtdoops: all blocks bad!\n");
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return;
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}
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}
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if (ret < 0) {
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printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n");
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return;
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}
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for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
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ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size);
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if (ret >= 0) {
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printk(KERN_DEBUG "mtdoops: ready %d, %d\n",
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cxt->nextpage, cxt->nextcount);
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return;
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}
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if (ret == -EIO) {
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ret = mtd_block_markbad(mtd, cxt->nextpage * record_size);
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if (ret < 0 && ret != -EOPNOTSUPP) {
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printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n");
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return;
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}
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}
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goto badblock;
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}
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static void mtdoops_write(struct mtdoops_context *cxt, int panic)
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{
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struct mtd_info *mtd = cxt->mtd;
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size_t retlen;
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u32 *hdr;
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int ret;
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if (test_and_set_bit(0, &cxt->oops_buf_busy))
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return;
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/* Add mtdoops header to the buffer */
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hdr = cxt->oops_buf;
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hdr[0] = cxt->nextcount;
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hdr[1] = MTDOOPS_KERNMSG_MAGIC;
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if (panic) {
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ret = mtd_panic_write(mtd, cxt->nextpage * record_size,
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record_size, &retlen, cxt->oops_buf);
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if (ret == -EOPNOTSUPP) {
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printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n");
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goto out;
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}
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} else
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ret = mtd_write(mtd, cxt->nextpage * record_size,
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record_size, &retlen, cxt->oops_buf);
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if (retlen != record_size || ret < 0)
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printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n",
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cxt->nextpage * record_size, retlen, record_size, ret);
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mark_page_used(cxt, cxt->nextpage);
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memset(cxt->oops_buf, 0xff, record_size);
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mtdoops_inc_counter(cxt);
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out:
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clear_bit(0, &cxt->oops_buf_busy);
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}
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static void mtdoops_workfunc_write(struct work_struct *work)
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{
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struct mtdoops_context *cxt =
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container_of(work, struct mtdoops_context, work_write);
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mtdoops_write(cxt, 0);
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}
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static void find_next_position(struct mtdoops_context *cxt)
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{
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struct mtd_info *mtd = cxt->mtd;
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int ret, page, maxpos = 0;
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u32 count[2], maxcount = 0xffffffff;
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size_t retlen;
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for (page = 0; page < cxt->oops_pages; page++) {
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if (mtd_block_isbad(mtd, page * record_size))
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continue;
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/* Assume the page is used */
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mark_page_used(cxt, page);
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ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,
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&retlen, (u_char *)&count[0]);
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if (retlen != MTDOOPS_HEADER_SIZE ||
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(ret < 0 && !mtd_is_bitflip(ret))) {
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printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n",
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page * record_size, retlen,
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MTDOOPS_HEADER_SIZE, ret);
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continue;
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}
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if (count[0] == 0xffffffff && count[1] == 0xffffffff)
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mark_page_unused(cxt, page);
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if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC)
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continue;
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if (maxcount == 0xffffffff) {
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maxcount = count[0];
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maxpos = page;
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} else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {
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maxcount = count[0];
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maxpos = page;
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} else if (count[0] > maxcount && count[0] < 0xc0000000) {
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maxcount = count[0];
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maxpos = page;
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} else if (count[0] > maxcount && count[0] > 0xc0000000
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&& maxcount > 0x80000000) {
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maxcount = count[0];
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maxpos = page;
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}
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}
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if (maxcount == 0xffffffff) {
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cxt->nextpage = cxt->oops_pages - 1;
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cxt->nextcount = 0;
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}
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else {
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cxt->nextpage = maxpos;
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cxt->nextcount = maxcount;
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}
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mtdoops_inc_counter(cxt);
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}
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static void mtdoops_do_dump(struct kmsg_dumper *dumper,
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enum kmsg_dump_reason reason)
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{
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struct mtdoops_context *cxt = container_of(dumper,
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struct mtdoops_context, dump);
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struct kmsg_dump_iter iter;
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/* Only dump oopses if dump_oops is set */
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if (reason == KMSG_DUMP_OOPS && !dump_oops)
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return;
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kmsg_dump_rewind(&iter);
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if (test_and_set_bit(0, &cxt->oops_buf_busy))
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return;
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kmsg_dump_get_buffer(&iter, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE,
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record_size - MTDOOPS_HEADER_SIZE, NULL);
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clear_bit(0, &cxt->oops_buf_busy);
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if (reason != KMSG_DUMP_OOPS) {
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/* Panics must be written immediately */
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mtdoops_write(cxt, 1);
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} else {
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/* For other cases, schedule work to write it "nicely" */
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schedule_work(&cxt->work_write);
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}
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}
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static void mtdoops_notify_add(struct mtd_info *mtd)
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{
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struct mtdoops_context *cxt = &oops_cxt;
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u64 mtdoops_pages = div_u64(mtd->size, record_size);
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int err;
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if (!strcmp(mtd->name, mtddev))
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cxt->mtd_index = mtd->index;
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if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
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return;
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if (mtd->size < mtd->erasesize * 2) {
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printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n",
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mtd->index);
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return;
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}
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if (mtd->erasesize < record_size) {
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printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n",
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mtd->index);
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return;
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}
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if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
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printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
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mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
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return;
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}
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/* oops_page_used is a bit field */
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cxt->oops_page_used =
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vmalloc(array_size(sizeof(unsigned long),
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DIV_ROUND_UP(mtdoops_pages,
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BITS_PER_LONG)));
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if (!cxt->oops_page_used) {
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printk(KERN_ERR "mtdoops: could not allocate page array\n");
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return;
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}
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cxt->dump.max_reason = KMSG_DUMP_OOPS;
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cxt->dump.dump = mtdoops_do_dump;
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err = kmsg_dump_register(&cxt->dump);
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if (err) {
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printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err);
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vfree(cxt->oops_page_used);
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cxt->oops_page_used = NULL;
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return;
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}
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cxt->mtd = mtd;
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cxt->oops_pages = (int)mtd->size / record_size;
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find_next_position(cxt);
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printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
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}
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static void mtdoops_notify_remove(struct mtd_info *mtd)
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{
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struct mtdoops_context *cxt = &oops_cxt;
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if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
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return;
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if (kmsg_dump_unregister(&cxt->dump) < 0)
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printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n");
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cxt->mtd = NULL;
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flush_work(&cxt->work_erase);
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flush_work(&cxt->work_write);
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}
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static struct mtd_notifier mtdoops_notifier = {
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.add = mtdoops_notify_add,
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.remove = mtdoops_notify_remove,
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};
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static int __init mtdoops_init(void)
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{
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struct mtdoops_context *cxt = &oops_cxt;
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int mtd_index;
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char *endp;
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if (strlen(mtddev) == 0) {
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printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n");
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return -EINVAL;
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}
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if ((record_size & 4095) != 0) {
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printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n");
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return -EINVAL;
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}
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if (record_size < 4096) {
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printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n");
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return -EINVAL;
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}
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/* Setup the MTD device to use */
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cxt->mtd_index = -1;
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mtd_index = simple_strtoul(mtddev, &endp, 0);
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if (*endp == '\0')
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cxt->mtd_index = mtd_index;
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cxt->oops_buf = vmalloc(record_size);
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if (!cxt->oops_buf)
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return -ENOMEM;
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memset(cxt->oops_buf, 0xff, record_size);
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cxt->oops_buf_busy = 0;
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INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
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INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
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register_mtd_user(&mtdoops_notifier);
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return 0;
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}
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static void __exit mtdoops_exit(void)
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{
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struct mtdoops_context *cxt = &oops_cxt;
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unregister_mtd_user(&mtdoops_notifier);
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vfree(cxt->oops_buf);
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vfree(cxt->oops_page_used);
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}
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module_init(mtdoops_init);
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module_exit(mtdoops_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
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MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");
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