/* * 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/spinlock.h> #include <linux/interrupt.h> #include <linux/mtd/mtd.h> #define MTDOOPS_KERNMSG_MAGIC 0x5d005d00 #define OOPS_PAGE_SIZE 4096 static struct mtdoops_context { int mtd_index; struct work_struct work_erase; struct work_struct work_write; struct mtd_info *mtd; int oops_pages; int nextpage; int nextcount; void *oops_buf; /* writecount and disabling ready are spin lock protected */ spinlock_t writecount_lock; int ready; int writecount; } oops_cxt; 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 mtd_info *mtd, int offset) { struct erase_info erase; DECLARE_WAITQUEUE(wait, current); wait_queue_head_t wait_q; int ret; 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, mtd->name); return ret; } schedule(); /* Wait for erase to finish. */ remove_wait_queue(&wait_q, &wait); return 0; } static void mtdoops_inc_counter(struct mtdoops_context *cxt) { struct mtd_info *mtd = cxt->mtd; size_t retlen; u32 count; int ret; cxt->nextpage++; if (cxt->nextpage >= cxt->oops_pages) cxt->nextpage = 0; cxt->nextcount++; if (cxt->nextcount == 0xffffffff) cxt->nextcount = 0; ret = mtd->read(mtd, cxt->nextpage * OOPS_PAGE_SIZE, 4, &retlen, (u_char *) &count); if ((retlen != 4) || ((ret < 0) && (ret != -EUCLEAN))) { printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)" ", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE, retlen, ret); schedule_work(&cxt->work_erase); return; } /* See if we need to erase the next block */ if (count != 0xffffffff) { schedule_work(&cxt->work_erase); return; } printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n", cxt->nextpage, cxt->nextcount); cxt->ready = 1; } /* 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 * OOPS_PAGE_SIZE) % mtd->erasesize; if (mod != 0) { cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / OOPS_PAGE_SIZE); if (cxt->nextpage >= cxt->oops_pages) cxt->nextpage = 0; } while (mtd->block_isbad) { ret = mtd->block_isbad(mtd, cxt->nextpage * OOPS_PAGE_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 %08x\n", cxt->nextpage * OOPS_PAGE_SIZE); i++; cxt->nextpage = cxt->nextpage + (mtd->erasesize / OOPS_PAGE_SIZE); if (cxt->nextpage >= cxt->oops_pages) cxt->nextpage = 0; if (i == (cxt->oops_pages / (mtd->erasesize / OOPS_PAGE_SIZE))) { printk(KERN_ERR "mtdoops: All blocks bad!\n"); return; } } for (j = 0, ret = -1; (j < 3) && (ret < 0); j++) ret = mtdoops_erase_block(mtd, cxt->nextpage * OOPS_PAGE_SIZE); if (ret >= 0) { printk(KERN_DEBUG "mtdoops: Ready %d, %d \n", cxt->nextpage, cxt->nextcount); cxt->ready = 1; return; } if (mtd->block_markbad && (ret == -EIO)) { ret = mtd->block_markbad(mtd, cxt->nextpage * OOPS_PAGE_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; int ret; if (cxt->writecount < OOPS_PAGE_SIZE) memset(cxt->oops_buf + cxt->writecount, 0xff, OOPS_PAGE_SIZE - cxt->writecount); if (panic) ret = mtd->panic_write(mtd, cxt->nextpage * OOPS_PAGE_SIZE, OOPS_PAGE_SIZE, &retlen, cxt->oops_buf); else ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE, OOPS_PAGE_SIZE, &retlen, cxt->oops_buf); cxt->writecount = 0; if ((retlen != OOPS_PAGE_SIZE) || (ret < 0)) printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE, retlen, OOPS_PAGE_SIZE, ret); 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++) { ret = mtd->read(mtd, page * OOPS_PAGE_SIZE, 8, &retlen, (u_char *) &count[0]); if ((retlen != 8) || ((ret < 0) && (ret != -EUCLEAN))) { printk(KERN_ERR "mtdoops: Read failure at %d (%td of 8 read)" ", err %d.\n", page * OOPS_PAGE_SIZE, retlen, ret); continue; } if (count[1] != MTDOOPS_KERNMSG_MAGIC) continue; 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_notify_add(struct mtd_info *mtd) { struct mtdoops_context *cxt = &oops_cxt; if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0) return; if (mtd->size < (mtd->erasesize * 2)) { printk(KERN_ERR "MTD partition %d not big enough for mtdoops\n", mtd->index); return; } if (mtd->erasesize < OOPS_PAGE_SIZE) { printk(KERN_ERR "Eraseblock size of MTD partition %d too small\n", mtd->index); return; } cxt->mtd = mtd; if (mtd->size > INT_MAX) cxt->oops_pages = INT_MAX / OOPS_PAGE_SIZE; else cxt->oops_pages = (int)mtd->size / OOPS_PAGE_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; cxt->mtd = NULL; flush_scheduled_work(); } static void mtdoops_console_sync(void) { struct mtdoops_context *cxt = &oops_cxt; struct mtd_info *mtd = cxt->mtd; unsigned long flags; if (!cxt->ready || !mtd || cxt->writecount == 0) return; /* * Once ready is 0 and we've held the lock no further writes to the * buffer will happen */ spin_lock_irqsave(&cxt->writecount_lock, flags); if (!cxt->ready) { spin_unlock_irqrestore(&cxt->writecount_lock, flags); return; } cxt->ready = 0; spin_unlock_irqrestore(&cxt->writecount_lock, flags); if (mtd->panic_write && in_interrupt()) /* Interrupt context, we're going to panic so try and log */ mtdoops_write(cxt, 1); else schedule_work(&cxt->work_write); } static void mtdoops_console_write(struct console *co, const char *s, unsigned int count) { struct mtdoops_context *cxt = co->data; struct mtd_info *mtd = cxt->mtd; unsigned long flags; if (!oops_in_progress) { mtdoops_console_sync(); return; } if (!cxt->ready || !mtd) return; /* Locking on writecount ensures sequential writes to the buffer */ spin_lock_irqsave(&cxt->writecount_lock, flags); /* Check ready status didn't change whilst waiting for the lock */ if (!cxt->ready) return; if (cxt->writecount == 0) { u32 *stamp = cxt->oops_buf; *stamp++ = cxt->nextcount; *stamp = MTDOOPS_KERNMSG_MAGIC; cxt->writecount = 8; } if ((count + cxt->writecount) > OOPS_PAGE_SIZE) count = OOPS_PAGE_SIZE - cxt->writecount; memcpy(cxt->oops_buf + cxt->writecount, s, count); cxt->writecount += count; spin_unlock_irqrestore(&cxt->writecount_lock, flags); if (cxt->writecount == OOPS_PAGE_SIZE) mtdoops_console_sync(); } static int __init mtdoops_console_setup(struct console *co, char *options) { struct mtdoops_context *cxt = co->data; if (cxt->mtd_index != -1) return -EBUSY; if (co->index == -1) return -EINVAL; cxt->mtd_index = co->index; return 0; } static struct mtd_notifier mtdoops_notifier = { .add = mtdoops_notify_add, .remove = mtdoops_notify_remove, }; static struct console mtdoops_console = { .name = "ttyMTD", .write = mtdoops_console_write, .setup = mtdoops_console_setup, .unblank = mtdoops_console_sync, .index = -1, .data = &oops_cxt, }; static int __init mtdoops_console_init(void) { struct mtdoops_context *cxt = &oops_cxt; cxt->mtd_index = -1; cxt->oops_buf = vmalloc(OOPS_PAGE_SIZE); if (!cxt->oops_buf) { printk(KERN_ERR "Failed to allocate mtdoops buffer workspace\n"); return -ENOMEM; } INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase); INIT_WORK(&cxt->work_write, mtdoops_workfunc_write); register_console(&mtdoops_console); register_mtd_user(&mtdoops_notifier); return 0; } static void __exit mtdoops_console_exit(void) { struct mtdoops_context *cxt = &oops_cxt; unregister_mtd_user(&mtdoops_notifier); unregister_console(&mtdoops_console); vfree(cxt->oops_buf); } subsys_initcall(mtdoops_console_init); module_exit(mtdoops_console_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); MODULE_DESCRIPTION("MTD Oops/Panic console logger/driver");