/* * MTD Oops/Panic logger * * Copyright (C) 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; /* 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_scheduled_work(); } 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");