inftlmount.c

linux下的MTD设备驱动源代码,配合jffs2 yaffss2文件系统.

/* 
 * inftlmount.c -- INFTL mount code with extensive checks.
 *
 * Author: Greg Ungerer ([e-mail])
 * (C) Copyright 2002-2003, Greg Ungerer ([e-mail])
 *
 * Based heavily on the nftlmount.c code which is:
 * Author: Fabrice Bellard ([e-mail]) 
 * Copyright (C) 2000 Netgem S.A.
 *
 * $Id: inftlmount.c,v 1.12 2003/06/26 07:31:36 dwmw2 Exp $
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nftl.h>
#include <linux/mtd/inftl.h>
#include <linux/mtd/compatmac.h>

char inftlmountrev[]="$Revision: 1.12 $";

/*
 * find_boot_record: Find the INFTL Media Header and its Spare copy which
 *	contains the various device information of the INFTL partition and
 *	Bad Unit Table. Update the PUtable[] table according to the Bad
 *	Unit Table. PUtable[] is used for management of Erase Unit in
 *	other routines in inftlcore.c and inftlmount.c.
 */
static int find_boot_record(struct INFTLrecord *inftl)
{
	struct inftl_unittail h1;
	//struct inftl_oob oob;
	unsigned int i, block, boot_record_count = 0;
	u8 buf[SECTORSIZE];
	struct INFTLMediaHeader *mh = &inftl->MediaHdr;
	struct INFTLPartition *ip;
	int retlen;

	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: find_boot_record(inftl=0x%x)\n",
		(int)inftl);

        /*
	 * Assume logical EraseSize == physical erasesize for starting the
	 * scan. We'll sort it out later if we find a MediaHeader which says
	 * otherwise.
	 */
	inftl->EraseSize = inftl->mbd.mtd->erasesize;
        inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;

	inftl->MediaUnit = BLOCK_NIL;
	inftl->SpareMediaUnit = BLOCK_NIL;

	/* Search for a valid boot record */
	for (block = 0; block < inftl->nb_blocks; block++) {
		int ret;

		/*
		 * Check for BNAND header first. Then whinge if it's found
		 * but later checks fail.
		 */
		if ((ret = MTD_READ(inftl->mbd.mtd, block * inftl->EraseSize,
		    SECTORSIZE, &retlen, buf))) {
			static int warncount = 5;

			if (warncount) {
				printk(KERN_WARNING "INFTL: block read at 0x%x "
					"of mtd%d failed: %d\n",
					block * inftl->EraseSize,
					inftl->mbd.mtd->index, ret);
				if (!--warncount)
					printk(KERN_WARNING "INFTL: further "
						"failures for this block will "
						"not be printed\n");
			}
			continue;
		}

		if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
			/* BNAND\0 not found. Continue */
			continue;
		}

		/* To be safer with BIOS, also use erase mark as discriminant */
		if ((ret = MTD_READOOB(inftl->mbd.mtd, block * inftl->EraseSize +
		    SECTORSIZE + 8, 8, &retlen, (char *)&h1) < 0)) {
			printk(KERN_WARNING "INFTL: ANAND header found at "
				"0x%x in mtd%d, but OOB data read failed "
				"(err %d)\n", block * inftl->EraseSize,
				inftl->mbd.mtd->index, ret);
			continue;
		}

		if (boot_record_count) {
			/*
			 * We've already processed one. So we just check if
			 * this one is the same as the first one we found.
			 */
			if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
				printk(KERN_WARNING "INFTL: Media Headers at "
					"0x%x and 0x%x disagree.\n",
					inftl->MediaUnit * inftl->EraseSize,
					block * inftl->EraseSize);
				return -1;
			}
			if (boot_record_count == 1)
				inftl->SpareMediaUnit = block;

			/*
			 * Mark this boot record (INFTL MediaHeader) block as
			 * reserved.
			 */
			inftl->PUtable[block] = BLOCK_RESERVED;

			boot_record_count++;
			continue;
		}

		/*
		 * This is the first we've seen.
		 * Copy the media header structure into place.
		 */
		memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
		mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
		mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
		mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
		mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
		mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
		mh->PercentUsed = le32_to_cpu(mh->PercentUsed);

#ifdef CONFIG_MTD_DEBUG_VERBOSE
		if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
			printk("INFTL: Media Header ->\n"
				"    bootRecordID          = %s\n"
				"    NoOfBootImageBlocks   = %d\n"
				"    NoOfBinaryPartitions  = %d\n"
				"    NoOfBDTLPartitions    = %d\n"
				"    BlockMultiplerBits    = %d\n"
				"    FormatFlgs            = %d\n"
				"    OsakVersion           = 0x%x\n"
				"    PercentUsed           = %d\n",
				mh->bootRecordID, mh->NoOfBootImageBlocks,
				mh->NoOfBinaryPartitions,
				mh->NoOfBDTLPartitions,
				mh->BlockMultiplierBits, mh->FormatFlags,
				mh->OsakVersion, mh->PercentUsed);
		}
#endif

		if (mh->NoOfBDTLPartitions == 0) {
			printk(KERN_WARNING "INFTL: Media Header sanity check "
				"failed: NoOfBDTLPartitions (%d) == 0, "
				"must be at least 1\n", mh->NoOfBDTLPartitions);
			return -1;
		}

		if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
			printk(KERN_WARNING "INFTL: Media Header sanity check "
				"failed: Total Partitions (%d) > 4, "
				"BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
				mh->NoOfBinaryPartitions,
				mh->NoOfBDTLPartitions,
				mh->NoOfBinaryPartitions);
			return -1;
		}

		if (mh->BlockMultiplierBits > 1) {
			printk(KERN_WARNING "INFTL: sorry, we don't support "
				"UnitSizeFactor 0x%02x\n",
				mh->BlockMultiplierBits);
			return -1;
		} else if (mh->BlockMultiplierBits == 1) {
			printk(KERN_WARNING "INFTL: support for INFTL with "
				"UnitSizeFactor 0x%02x is experimental\n",
				mh->BlockMultiplierBits);
			inftl->EraseSize = inftl->mbd.mtd->erasesize <<
				(0xff - mh->BlockMultiplierBits);
			inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
		}

		/* Scan the partitions */
		for (i = 0; (i < 4); i++) {
			ip = &mh->Partitions[i];
			ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
			ip->firstUnit = le32_to_cpu(ip->firstUnit);
			ip->lastUnit = le32_to_cpu(ip->lastUnit);
			ip->flags = le32_to_cpu(ip->flags);
			ip->spareUnits = le32_to_cpu(ip->spareUnits);
			ip->Reserved0 = le32_to_cpu(ip->Reserved0);

#ifdef CONFIG_MTD_DEBUG_VERBOSE
			if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
				printk("    PARTITION[%d] ->\n"
					"        virtualUnits    = %d\n"
					"        firstUnit       = %d\n"
					"        lastUnit        = %d\n"
					"        flags           = 0x%x\n"
					"        spareUnits      = %d\n",
					i, ip->virtualUnits, ip->firstUnit,
					ip->lastUnit, ip->flags,
					ip->spareUnits);
			}
#endif

			if (ip->Reserved0 != ip->firstUnit) {
				struct erase_info *instr = &inftl->instr;

				/*
				 * 	Most likely this is using the
				 * 	undocumented qiuck mount feature.
				 * 	We don't support that, we will need
				 * 	to erase the hidden block for full
				 * 	compatibility.
				 */
				instr->addr = ip->Reserved0 * inftl->EraseSize;
				instr->len = inftl->EraseSize;
				MTD_ERASE(inftl->mbd.mtd, instr);
			}
			if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
				printk(KERN_WARNING "INFTL: Media Header "
					"Partition %d sanity check failed\n"
					"    firstUnit %d : lastUnit %d  >  "
					"virtualUnits %d\n", i, ip->lastUnit,
					ip->firstUnit, ip->Reserved0);
				return -1;
			}
			if (ip->Reserved1 != 0) {
				printk(KERN_WARNING "INFTL: Media Header "
					"Partition %d sanity check failed: "
					"Reserved1 %d != 0\n",
					i, ip->Reserved1);
				return -1;
			}

			if (ip->flags & INFTL_BDTL)
				break;
		}

		if (i >= 4) {
			printk(KERN_WARNING "INFTL: Media Header Partition "
				"sanity check failed:\n       No partition "
				"marked as Disk Partition\n");
			return -1;
		}

		inftl->nb_boot_blocks = ip->firstUnit;
		inftl->numvunits = ip->virtualUnits;
		if (inftl->numvunits > (inftl->nb_blocks -
		    inftl->nb_boot_blocks - 2)) {
			printk(KERN_WARNING "INFTL: Media Header sanity check "
				"failed:\n        numvunits (%d) > nb_blocks "
				"(%d) - nb_boot_blocks(%d) - 2\n",
				inftl->numvunits, inftl->nb_blocks,
				inftl->nb_boot_blocks);
			return -1;
		}
		
		inftl->mbd.size  = inftl->numvunits *
			(inftl->EraseSize / SECTORSIZE);

		/*
		 * Block count is set to last used EUN (we won't need to keep
		 * any meta-data past that point).
		 */
		inftl->firstEUN = ip->firstUnit;
		inftl->lastEUN = ip->lastUnit;
		inftl->nb_blocks = ip->lastUnit + 1;

		/* Memory alloc */
		inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
		if (!inftl->PUtable) {
			printk(KERN_WARNING "INFTL: allocation of PUtable "
				"failed (%d bytes)\n",
				inftl->nb_blocks * sizeof(u16));
			return -ENOMEM;
		}

		inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
		if (!inftl->VUtable) {
			kfree(inftl->PUtable);
			printk(KERN_WARNING "INFTL: allocation of VUtable "
				"failed (%d bytes)\n",
				inftl->nb_blocks * sizeof(u16));
			return -ENOMEM;
		}
		
		/* Mark the blocks before INFTL MediaHeader as reserved */
		for (i = 0; i < inftl->nb_boot_blocks; i++)
			inftl->PUtable[i] = BLOCK_RESERVED;
		/* Mark all remaining blocks as potentially containing data */
		for (; i < inftl->nb_blocks; i++)
			inftl->PUtable[i] = BLOCK_NOTEXPLORED;

		/* Mark this boot record (NFTL MediaHeader) block as reserved */
		inftl->PUtable[block] = BLOCK_RESERVED;

#if 0
		/* Read Bad Erase Unit Table and modify PUtable[] accordingly */
		for (i = 0; i < inftl->nb_blocks; i++) {
			if ((i & (SECTORSIZE - 1)) == 0) {
				/* read one sector for every SECTORSIZE of blocks */
				if ((ret = MTD_READECC(inftl->mbd.mtd,
				    block * inftl->EraseSize + i + SECTORSIZE,
				    SECTORSIZE, &retlen, buf,
				    (char *)&oob, NULL)) < 0) {
					printk(KERN_WARNING "INFTL: read of "
						"bad sector table failed "
						"(err %d)\n", ret);
					kfree(inftl->VUtable);
					kfree(inftl->PUtable);
					return -1;
				}
			}
			/* Mark the Bad Erase Unit as RESERVED in PUtable */
			if (buf[i & (SECTORSIZE - 1)] != 0xff)
				inftl->PUtable[i] = BLOCK_RESERVED;
		}
#endif

		inftl->MediaUnit = block;
		boot_record_count++;
	}
		
	return boot_record_count ? 0 : -1;
}

static int memcmpb(void *a, int c, int n)
{
	int i;
	for (i = 0; i < n; i++) {
		if (c != ((unsigned char *)a)[i])
			return 1;
	}
	return 0;
}

/*
 * check_free_sector: check if a free sector is actually FREE,
 *	i.e. All 0xff in data and oob area.
 */
static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
	int len, int check_oob)
{
	int i, retlen;
	u8 buf[SECTORSIZE];

	DEBUG(MTD_DEBUG_LEVEL3, "INFTL: check_free_sectors(inftl=0x%x,"
		"address=0x%x,len=%d,check_oob=%d)\n", (int)inftl,
		address, len, check_oob);

	for (i = 0; i < len; i += SECTORSIZE) {
		/*
		 * We want to read the sector without ECC check here since a
		 * free sector does not have ECC syndrome on it yet.
		 */
		if (MTD_READ(inftl->mbd.mtd, address, SECTORSIZE, &retlen, buf) < 0)
			return -1;
		if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
			return -1;

		if (check_oob) {
			if (MTD_READOOB(inftl->mbd.mtd, address,
			    inftl->mbd.mtd->oobsize, &retlen, buf) < 0)
				return -1;
			if (memcmpb(buf, 0xff, inftl->mbd.mtd->oobsize) != 0)
				return -1;
		}
		address += SECTORSIZE;
	}

	return 0;
}

/*
 * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
 *		 Unit and Update INFTL metadata. Each erase operation is
 *		 checked with check_free_sectors.
 *
 * Return: 0 when succeed, -1 on error.
 *
 * ToDo: 1. Is it neceressary to check_free_sector after erasing ?? 
 *       2. UnitSizeFactor != 0xFF
 */
int INFTL_formatblock(struct INFTLrecord *inftl, int block)
{
	int retlen;