Release 4.7 drivers/mtd/nftlcore.c

/*
 * Linux driver for NAND Flash Translation Layer
 *
 * Copyright © 1999 Machine Vision Holdings, Inc.
 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
 *
 * 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
 */


#define PRERELEASE

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/hdreg.h>
#include <linux/blkdev.h>

#include <linux/kmod.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/nand.h>
#include <linux/mtd/nftl.h>
#include <linux/mtd/blktrans.h>

/* maximum number of loops while examining next block, to have a
   chance to detect consistency problems (they should never happen
   because of the checks done in the mounting */


#define MAX_LOOPS 10000




static void nftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
{
	struct NFTLrecord *nftl;
	unsigned long temp;

	if (!mtd_type_is_nand(mtd) || mtd->size > UINT_MAX)
		return;
	/* OK, this is moderately ugly.  But probably safe.  Alternatives? */
	if (memcmp(mtd->name, "DiskOnChip", 10))
		return;

	pr_debug("NFTL: add_mtd for %s\n", mtd->name);

	nftl = kzalloc(sizeof(struct NFTLrecord), GFP_KERNEL);

	if (!nftl)
		return;

	nftl->mbd.mtd = mtd;
	nftl->mbd.devnum = -1;

	nftl->mbd.tr = tr;

        if (NFTL_mount(nftl) < 0) {
		printk(KERN_WARNING "NFTL: could not mount device\n");
		kfree(nftl);
		return;
        }

	/* OK, it's a new one. Set up all the data structures. */

	/* Calculate geometry */
	nftl->cylinders = 1024;
	nftl->heads = 16;

	temp = nftl->cylinders * nftl->heads;
	nftl->sectors = nftl->mbd.size / temp;
	if (nftl->mbd.size % temp) {
		nftl->sectors++;
		temp = nftl->cylinders * nftl->sectors;
		nftl->heads = nftl->mbd.size / temp;

		if (nftl->mbd.size % temp) {
			nftl->heads++;
			temp = nftl->heads * nftl->sectors;
			nftl->cylinders = nftl->mbd.size / temp;
		}
	}

	if (nftl->mbd.size != nftl->heads * nftl->cylinders * nftl->sectors) {
		/*
                  Oh no we don't have
                   mbd.size == heads * cylinders * sectors
                */
		printk(KERN_WARNING "NFTL: cannot calculate a geometry to "
		       "match size of 0x%lx.\n", nftl->mbd.size);
		printk(KERN_WARNING "NFTL: using C:%d H:%d S:%d "
			"(== 0x%lx sects)\n",
			nftl->cylinders, nftl->heads , nftl->sectors,
			(long)nftl->cylinders * (long)nftl->heads *
			(long)nftl->sectors );
	}

	if (add_mtd_blktrans_dev(&nftl->mbd)) {
		kfree(nftl->ReplUnitTable);
		kfree(nftl->EUNtable);
		kfree(nftl);
		return;
	}
#ifdef PSYCHO_DEBUG
	printk(KERN_INFO "NFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a');
#endif
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
243
65.32%
2
14.29%
david woodhouse
david woodhouse
103
27.69%
3
21.43%
al viro
al viro
13
3.49%
4
28.57%
adrian hunter
adrian hunter
6
1.61%
1
7.14%
huang shijie
huang shijie
4
1.08%
1
7.14%
burman yan
burman yan
1
0.27%
1
7.14%
brian norris
brian norris
1
0.27%
1
7.14%
thomas gleixner
thomas gleixner
1
0.27%
1
7.14%
Total
372
100.00%
14
100.00%



static void nftl_remove_dev(struct mtd_blktrans_dev *dev)
{
	struct NFTLrecord *nftl = (void *)dev;

	pr_debug("NFTL: remove_dev (i=%d)\n", dev->devnum);

	del_mtd_blktrans_dev(dev);
	kfree(nftl->ReplUnitTable);
	kfree(nftl->EUNtable);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
31
62.00%
2
50.00%
david woodhouse
david woodhouse
18
36.00%
1
25.00%
brian norris
brian norris
1
2.00%
1
25.00%
Total
50
100.00%
4
100.00%

/*
 * Read oob data from flash
 */


int nftl_read_oob(struct mtd_info *mtd, loff_t offs, size_t len,
		  size_t *retlen, uint8_t *buf)
{
	loff_t mask = mtd->writesize - 1;
	struct mtd_oob_ops ops;
	int res;

	ops.mode = MTD_OPS_PLACE_OOB;
	ops.ooboffs = offs & mask;
	ops.ooblen = len;
	ops.oobbuf = buf;
	ops.datbuf = NULL;

	res = mtd_read_oob(mtd, offs & ~mask, &ops);
	*retlen = ops.oobretlen;
	return res;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
thomas gleixner
thomas gleixner
83
85.57%
1
20.00%
dimitri gorokhovik
dimitri gorokhovik
11
11.34%
1
20.00%
vitaly wool
vitaly wool
1
1.03%
1
20.00%
artem bityutskiy
artem bityutskiy
1
1.03%
1
20.00%
brian norris
brian norris
1
1.03%
1
20.00%
Total
97
100.00%
5
100.00%

/*
 * Write oob data to flash
 */


int nftl_write_oob(struct mtd_info *mtd, loff_t offs, size_t len,
		   size_t *retlen, uint8_t *buf)
{
	loff_t mask = mtd->writesize - 1;
	struct mtd_oob_ops ops;
	int res;

	ops.mode = MTD_OPS_PLACE_OOB;
	ops.ooboffs = offs & mask;
	ops.ooblen = len;
	ops.oobbuf = buf;
	ops.datbuf = NULL;

	res = mtd_write_oob(mtd, offs & ~mask, &ops);
	*retlen = ops.oobretlen;
	return res;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
thomas gleixner
thomas gleixner
83
85.57%
1
20.00%
dimitri gorokhovik
dimitri gorokhovik
11
11.34%
1
20.00%
brian norris
brian norris
1
1.03%
1
20.00%
vitaly wool
vitaly wool
1
1.03%
1
20.00%
artem bityutskiy
artem bityutskiy
1
1.03%
1
20.00%
Total
97
100.00%
5
100.00%

#ifdef CONFIG_NFTL_RW

/*
 * Write data and oob to flash
 */


static int nftl_write(struct mtd_info *mtd, loff_t offs, size_t len,
		      size_t *retlen, uint8_t *buf, uint8_t *oob)
{
	loff_t mask = mtd->writesize - 1;
	struct mtd_oob_ops ops;
	int res;

	ops.mode = MTD_OPS_PLACE_OOB;
	ops.ooboffs = offs & mask;
	ops.ooblen = mtd->oobsize;
	ops.oobbuf = oob;
	ops.datbuf = buf;
	ops.len = len;

	res = mtd_write_oob(mtd, offs & ~mask, &ops);
	*retlen = ops.retlen;
	return res;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
thomas gleixner
thomas gleixner
96
87.27%
1
20.00%
dimitri gorokhovik
dimitri gorokhovik
12
10.91%
2
40.00%
artem bityutskiy
artem bityutskiy
1
0.91%
1
20.00%
brian norris
brian norris
1
0.91%
1
20.00%
Total
110
100.00%
5
100.00%

/* Actual NFTL access routines */
/* NFTL_findfreeblock: Find a free Erase Unit on the NFTL partition. This function is used
 *      when the give Virtual Unit Chain
 */


static u16 NFTL_findfreeblock(struct NFTLrecord *nftl, int desperate )
{
	/* For a given Virtual Unit Chain: find or create a free block and
           add it to the chain */
	/* We're passed the number of the last EUN in the chain, to save us from
           having to look it up again */
	u16 pot = nftl->LastFreeEUN;
	int silly = nftl->nb_blocks;

	/* Normally, we force a fold to happen before we run out of free blocks completely */
	if (!desperate && nftl->numfreeEUNs < 2) {
		pr_debug("NFTL_findfreeblock: there are too few free EUNs\n");
		return BLOCK_NIL;
	}

	/* Scan for a free block */
	do {
		if (nftl->ReplUnitTable[pot] == BLOCK_FREE) {
			nftl->LastFreeEUN = pot;
			nftl->numfreeEUNs--;
			return pot;
		}

		/* This will probably point to the MediaHdr unit itself,
                   right at the beginning of the partition. But that unit
                   (and the backup unit too) should have the UCI set
                   up so that it's not selected for overwriting */
		if (++pot > nftl->lastEUN)
			pot = le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN);

		if (!silly--) {
			printk("Argh! No free blocks found! LastFreeEUN = %d, "
			       "FirstEUN = %d\n", nftl->LastFreeEUN,
			       le16_to_cpu(nftl->MediaHdr.FirstPhysicalEUN));
			return BLOCK_NIL;
		}
	} while (pot != nftl->LastFreeEUN);

	return BLOCK_NIL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
139
95.21%
2
40.00%
julia lawall
julia lawall
3
2.05%
1
20.00%
linus torvalds
linus torvalds
3
2.05%
1
20.00%
brian norris
brian norris
1
0.68%
1
20.00%
Total
146
100.00%
5
100.00%



static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock )
{
	struct mtd_info *mtd = nftl->mbd.mtd;
	u16 BlockMap[MAX_SECTORS_PER_UNIT];
	unsigned char BlockLastState[MAX_SECTORS_PER_UNIT];
	unsigned char BlockFreeFound[MAX_SECTORS_PER_UNIT];
	unsigned int thisEUN;
	int block;
	int silly;
	unsigned int targetEUN;
	struct nftl_oob oob;
	int inplace = 1;
	size_t retlen;

	memset(BlockMap, 0xff, sizeof(BlockMap));
	memset(BlockFreeFound, 0, sizeof(BlockFreeFound));

	thisEUN = nftl->EUNtable[thisVUC];

	if (thisEUN == BLOCK_NIL) {
		printk(KERN_WARNING "Trying to fold non-existent "
		       "Virtual Unit Chain %d!\n", thisVUC);
		return BLOCK_NIL;
	}

	/* Scan to find the Erase Unit which holds the actual data for each
           512-byte block within the Chain.
        */
	silly = MAX_LOOPS;
	targetEUN = BLOCK_NIL;
	while (thisEUN <= nftl->lastEUN ) {
		unsigned int status, foldmark;

		targetEUN = thisEUN;
		for (block = 0; block < nftl->EraseSize / 512; block ++) {
			nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) +
				      (block * 512), 16 , &retlen,
				      (char *)&oob);
			if (block == 2) {
				foldmark = oob.u.c.FoldMark | oob.u.c.FoldMark1;
				if (foldmark == FOLD_MARK_IN_PROGRESS) {
					pr_debug("Write Inhibited on EUN %d\n", thisEUN);
					inplace = 0;
				} else {
					/* There's no other reason not to do inplace,
                                           except ones that come later. So we don't need
                                           to preserve inplace */
					inplace = 1;
				}
			}
			status = oob.b.Status | oob.b.Status1;
			BlockLastState[block] = status;

			switch(status) {
			case SECTOR_FREE:
				BlockFreeFound[block] = 1;
				break;

			case SECTOR_USED:
				if (!BlockFreeFound[block])
					BlockMap[block] = thisEUN;
				else
					printk(KERN_WARNING
					       "SECTOR_USED found after SECTOR_FREE "
					       "in Virtual Unit Chain %d for block %d\n",
					       thisVUC, block);
				break;
			case SECTOR_DELETED:
				if (!BlockFreeFound[block])
					BlockMap[block] = BLOCK_NIL;
				else
					printk(KERN_WARNING
					       "SECTOR_DELETED found after SECTOR_FREE "
					       "in Virtual Unit Chain %d for block %d\n",
					       thisVUC, block);
				break;

			case SECTOR_IGNORE:
				break;
			default:
				printk("Unknown status for block %d in EUN %d: %x\n",
				       block, thisEUN, status);
			}
		}

		if (!silly--) {
			printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\n",
			       thisVUC);
			return BLOCK_NIL;
		}

		thisEUN = nftl->ReplUnitTable[thisEUN];
	}

	if (inplace) {
		/* We're being asked to be a fold-in-place. Check
                   that all blocks which actually have data associated
                   with them (i.e. BlockMap[block] != BLOCK_NIL) are
                   either already present or SECTOR_FREE in the target
                   block. If not, we're going to have to fold out-of-place
                   anyway.
                */
		for (block = 0; block < nftl->EraseSize / 512 ; block++) {
			if (BlockLastState[block] != SECTOR_FREE &&
			    BlockMap[block] != BLOCK_NIL &&
			    BlockMap[block] != targetEUN) {
				pr_debug("Setting inplace to 0. VUC %d, "
				      "block %d was %x lastEUN, "
				      "and is in EUN %d (%s) %d\n",
				      thisVUC, block, BlockLastState[block],
				      BlockMap[block],
				      BlockMap[block]== targetEUN ? "==" : "!=",
				      targetEUN);
				inplace = 0;
				break;
			}
		}

		if (pendingblock >= (thisVUC * (nftl->EraseSize / 512)) &&
		    pendingblock < ((thisVUC + 1)* (nftl->EraseSize / 512)) &&
		    BlockLastState[pendingblock - (thisVUC * (nftl->EraseSize / 512))] !=
		    SECTOR_FREE) {
			pr_debug("Pending write not free in EUN %d. "
			      "Folding out of place.\n", targetEUN);
			inplace = 0;
		}
	}

	if (!inplace) {
		pr_debug("Cannot fold Virtual Unit Chain %d in place. "
		      "Trying out-of-place\n", thisVUC);
		/* We need to find a targetEUN to fold into. */
		targetEUN = NFTL_findfreeblock(nftl, 1);
		if (targetEUN == BLOCK_NIL) {
			/* Ouch. Now we're screwed. We need to do a
                           fold-in-place of another chain to make room
                           for this one. We need a better way of selecting
                           which chain to fold, because makefreeblock will
                           only ask us to fold the same one again.
                        */
			printk(KERN_WARNING
			       "NFTL_findfreeblock(desperate) returns 0xffff.\n");
			return BLOCK_NIL;
		}
	} else {
		/* We put a fold mark in the chain we are folding only if we
               fold in place to help the mount check code. If we do not fold in
               place, it is possible to find the valid chain by selecting the
               longer one */
		oob.u.c.FoldMark = oob.u.c.FoldMark1 = cpu_to_le16(FOLD_MARK_IN_PROGRESS);
		oob.u.c.unused = 0xffffffff;
		nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 2 * 512 + 8,
			       8, &retlen, (char *)&oob.u);
	}

	/* OK. We now know the location of every block in the Virtual Unit Chain,
           and the Erase Unit into which we are supposed to be copying.
           Go for it.
        */
	pr_debug("Folding chain %d into unit %d\n", thisVUC, targetEUN);
	for (block = 0; block < nftl->EraseSize / 512 ; block++) {
		unsigned char movebuf[512];
		int ret;

		/* If it's in the target EUN already, or if it's pending write, do nothing */
		if (BlockMap[block] == targetEUN ||
		    (pendingblock == (thisVUC * (nftl->EraseSize / 512) + block))) {
			continue;
		}

		/* copy only in non free block (free blocks can only
                   happen in case of media errors or deleted blocks) */
		if (BlockMap[block] == BLOCK_NIL)
			continue;

		ret = mtd_read(mtd,
			       (nftl->EraseSize * BlockMap[block]) + (block * 512),
			       512,
			       &retlen,
			       movebuf);
		if (ret < 0 && !mtd_is_bitflip(ret)) {
			ret = mtd_read(mtd,
				       (nftl->EraseSize * BlockMap[block]) + (block * 512),
				       512,
				       &retlen,
				       movebuf);
			if (ret != -EIO)
				printk("Error went away on retry.\n");
		}
		memset(&oob, 0xff, sizeof(struct nftl_oob));
		oob.b.Status = oob.b.Status1 = SECTOR_USED;

		nftl_write(nftl->mbd.mtd, (nftl->EraseSize * targetEUN) +
			   (block * 512), 512, &retlen, movebuf, (char *)&oob);
	}

	/* add the header so that it is now a valid chain */
	oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);
	oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum = BLOCK_NIL;

	nftl_write_oob(mtd, (nftl->EraseSize * targetEUN) + 8,
		       8, &retlen, (char *)&oob.u);

	/* OK. We've moved the whole lot into the new block. Now we have to free the original blocks. */

	/* At this point, we have two different chains for this Virtual Unit, and no way to tell
           them apart. If we crash now, we get confused. However, both contain the same data, so we
           shouldn't actually lose data in this case. It's just that when we load up on a medium which
           has duplicate chains, we need to free one of the chains because it's not necessary any more.
        */
	thisEUN = nftl->EUNtable[thisVUC];
	pr_debug("Want to erase\n");

	/* For each block in the old chain (except the targetEUN of course),
           free it and make it available for future use */
	while (thisEUN <= nftl->lastEUN && thisEUN != targetEUN) {
		unsigned int EUNtmp;

		EUNtmp = nftl->ReplUnitTable[thisEUN];

		if (NFTL_formatblock(nftl, thisEUN) < 0) {
			/* could not erase : mark block as reserved
                         */
			nftl->ReplUnitTable[thisEUN] = BLOCK_RESERVED;
		} else {
			/* correctly erased : mark it as free */
			nftl->ReplUnitTable[thisEUN] = BLOCK_FREE;
			nftl->numfreeEUNs++;
		}
		thisEUN = EUNtmp;
	}

	/* Make this the new start of chain for thisVUC */
	nftl->ReplUnitTable[targetEUN] = BLOCK_NIL;
	nftl->EUNtable[thisVUC] = targetEUN;

	return targetEUN;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
977
90.05%
2
15.38%
linus torvalds
linus torvalds
37
3.41%
1
7.69%
david woodhouse
david woodhouse
31
2.86%
2
15.38%
thomas gleixner
thomas gleixner
27
2.49%
4
30.77%
brian norris
brian norris
10
0.92%
2
15.38%
artem bityutskiy
artem bityutskiy
2
0.18%
1
7.69%
julia lawall
julia lawall
1
0.09%
1
7.69%
Total
1085
100.00%
13
100.00%



static u16 NFTL_makefreeblock( struct NFTLrecord *nftl , unsigned pendingblock)
{
	/* This is the part that needs some cleverness applied.
           For now, I'm doing the minimum applicable to actually
           get the thing to work.
           Wear-levelling and other clever stuff needs to be implemented
           and we also need to do some assessment of the results when
           the system loses power half-way through the routine.
        */
	u16 LongestChain = 0;
	u16 ChainLength = 0, thislen;
	u16 chain, EUN;

	for (chain = 0; chain < le32_to_cpu(nftl->MediaHdr.FormattedSize) / nftl->EraseSize; chain++) {
		EUN = nftl->EUNtable[chain];
		thislen = 0;

		while (EUN <= nftl->lastEUN) {
			thislen++;
			//printk("VUC %d reaches len %d with EUN %d\n", chain, thislen, EUN);
			EUN = nftl->ReplUnitTable[EUN] & 0x7fff;
			if (thislen > 0xff00) {
				printk("Endless loop in Virtual Chain %d: Unit %x\n",
				       chain, EUN);
			}
			if (thislen > 0xff10) {
				/* Actually, don't return failure. Just ignore this chain and
                                   get on with it. */
				thislen = 0;
				break;
			}
		}

		if (thislen > ChainLength) {
			//printk("New longest chain is %d with length %d\n", chain, thislen);
			ChainLength = thislen;
			LongestChain = chain;
		}
	}

	if (ChainLength < 2) {
		printk(KERN_WARNING "No Virtual Unit Chains available for folding. "
		       "Failing request\n");
		return BLOCK_NIL;
	}

	return NFTL_foldchain (nftl, LongestChain, pendingblock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
166
96.51%
2
33.33%
linus torvalds
linus torvalds
3
1.74%
1
16.67%
david woodhouse
david woodhouse
1
0.58%
1
16.67%
thomas gleixner
thomas gleixner
1
0.58%
1
16.67%
julia lawall
julia lawall
1
0.58%
1
16.67%
Total
172
100.00%
6
100.00%

/* NFTL_findwriteunit: Return the unit number into which we can write
                       for this block. Make it available if it isn't already
*/


static inline u16 NFTL_findwriteunit(struct NFTLrecord *nftl, unsigned block)
{
	u16 lastEUN;
	u16 thisVUC = block / (nftl->EraseSize / 512);
	struct mtd_info *mtd = nftl->mbd.mtd;
	unsigned int writeEUN;
	unsigned long blockofs = (block * 512) & (nftl->EraseSize -1);
	size_t retlen;
	int silly, silly2 = 3;
	struct nftl_oob oob;

	do {
		/* Scan the media to find a unit in the VUC which has
                   a free space for the block in question.
                */

		/* This condition catches the 0x[7f]fff cases, as well as
                   being a sanity check for past-end-of-media access
                */
		lastEUN = BLOCK_NIL;
		writeEUN = nftl->EUNtable[thisVUC];
		silly = MAX_LOOPS;
		while (writeEUN <= nftl->lastEUN) {
			struct nftl_bci bci;
			size_t retlen;
			unsigned int status;

			lastEUN = writeEUN;

			nftl_read_oob(mtd,
				      (writeEUN * nftl->EraseSize) + blockofs,
				      8, &retlen, (char *)&bci);

			pr_debug("Status of block %d in EUN %d is %x\n",
			      block , writeEUN, le16_to_cpu(bci.Status));

			status = bci.Status | bci.Status1;
			switch(status) {
			case SECTOR_FREE:
				return writeEUN;

			case SECTOR_DELETED:
			case SECTOR_USED:
			case SECTOR_IGNORE:
				break;
			default:
				// Invalid block. Don't use it any more. Must implement.
				break;
			}

			if (!silly--) {
				printk(KERN_WARNING
				       "Infinite loop in Virtual Unit Chain 0x%x\n",
				       thisVUC);
				return BLOCK_NIL;
			}

			/* Skip to next block in chain */
			writeEUN = nftl->ReplUnitTable[writeEUN];
		}

		/* OK. We didn't find one in the existing chain, or there
                   is no existing chain. */

		/* Try to find an already-free block */
		writeEUN = NFTL_findfreeblock(nftl, 0);

		if (writeEUN == BLOCK_NIL) {
			/* That didn't work - there were no free blocks just
                           waiting to be picked up. We're going to have to fold
                           a chain to make room.
                        */

			/* First remember the start of this chain */
			//u16 startEUN = nftl->EUNtable[thisVUC];

			//printk("Write to VirtualUnitChain %d, calling makefreeblock()\n", thisVUC);
			writeEUN = NFTL_makefreeblock(nftl, BLOCK_NIL);

			if (writeEUN == BLOCK_NIL) {
				/* OK, we accept that the above comment is
                                   lying - there may have been free blocks
                                   last time we called NFTL_findfreeblock(),
                                   but they are reserved for when we're
                                   desperate. Well, now we're desperate.
                                */
				pr_debug("Using desperate==1 to find free EUN to accommodate write to VUC %d\n", thisVUC);
				writeEUN = NFTL_findfreeblock(nftl, 1);
			}
			if (writeEUN == BLOCK_NIL) {
				/* Ouch. This should never happen - we should
                                   always be able to make some room somehow.
                                   If we get here, we've allocated more storage
                                   space than actual media, or our makefreeblock
                                   routine is missing something.
                                */
				printk(KERN_WARNING "Cannot make free space.\n");
				return BLOCK_NIL;
			}
			//printk("Restarting scan\n");
			lastEUN = BLOCK_NIL;
			continue;
		}

		/* We've found a free block. Insert it into the chain. */

		if (lastEUN != BLOCK_NIL) {
			thisVUC |= 0x8000; /* It's a replacement block */
		} else {
			/* The first block in a new chain */
			nftl->EUNtable[thisVUC] = writeEUN;
		}

		/* set up the actual EUN we're writing into */
		/* Both in our cache... */
		nftl->ReplUnitTable[writeEUN] = BLOCK_NIL;

		/* ... and on the flash itself */
		nftl_read_oob(mtd, writeEUN * nftl->EraseSize + 8, 8,
			      &retlen, (char *)&oob.u);

		oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);

		nftl_write_oob(mtd, writeEUN * nftl->EraseSize + 8, 8,
			       &retlen, (char *)&oob.u);

		/* we link the new block to the chain only after the
                   block is ready. It avoids the case where the chain
                   could point to a free block */
		if (lastEUN != BLOCK_NIL) {
			/* Both in our cache... */
			nftl->ReplUnitTable[lastEUN] = writeEUN;
			/* ... and on the flash itself */
			nftl_read_oob(mtd, (lastEUN * nftl->EraseSize) + 8,
				      8, &retlen, (char *)&oob.u);

			oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum
				= cpu_to_le16(writeEUN);

			nftl_write_oob(mtd, (lastEUN * nftl->EraseSize) + 8,
				       8, &retlen, (char *)&oob.u);
		}

		return writeEUN;

	} while (silly2--);

	printk(KERN_WARNING "Error folding to make room for Virtual Unit Chain 0x%x\n",
	       thisVUC);
	return BLOCK_NIL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
493
90.29%
2
25.00%
thomas gleixner
thomas gleixner
25
4.58%
3
37.50%
linus torvalds
linus torvalds
23
4.21%
1
12.50%
julia lawall
julia lawall
3
0.55%
1
12.50%
brian norris
brian norris
2
0.37%
1
12.50%
Total
546
100.00%
8
100.00%



static int nftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
			   char *buffer)
{
	struct NFTLrecord *nftl = (void *)mbd;
	u16 writeEUN;
	unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1);
	size_t retlen;
	struct nftl_oob oob;

	writeEUN = NFTL_findwriteunit(nftl, block);

	if (writeEUN == BLOCK_NIL) {
		printk(KERN_WARNING
		       "NFTL_writeblock(): Cannot find block to write to\n");
		/* If we _still_ haven't got a block to use, we're screwed */
		return 1;
	}

	memset(&oob, 0xff, sizeof(struct nftl_oob));
	oob.b.Status = oob.b.Status1 = SECTOR_USED;

	nftl_write(nftl->mbd.mtd, (writeEUN * nftl->EraseSize) + blockofs,
		   512, &retlen, (char *)buffer, (char *)&oob);
	return 0;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
102
66.67%
2
40.00%
david woodhouse
david woodhouse
50
32.68%
2
40.00%
thomas gleixner
thomas gleixner
1
0.65%
1
20.00%
Total
153
100.00%
5
100.00%

#endif /* CONFIG_NFTL_RW */



static int nftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
			  char *buffer)
{
	struct NFTLrecord *nftl = (void *)mbd;
	struct mtd_info *mtd = nftl->mbd.mtd;
	u16 lastgoodEUN;
	u16 thisEUN = nftl->EUNtable[block / (nftl->EraseSize / 512)];
	unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1);
	unsigned int status;
	int silly = MAX_LOOPS;
	size_t retlen;
	struct nftl_bci bci;

	lastgoodEUN = BLOCK_NIL;

	if (thisEUN != BLOCK_NIL) {
		while (thisEUN < nftl->nb_blocks) {
			if (nftl_read_oob(mtd, (thisEUN * nftl->EraseSize) +
					  blockofs, 8, &retlen,
					  (char *)&bci) < 0)
				status = SECTOR_IGNORE;
			else
				status = bci.Status | bci.Status1;

			switch (status) {
			case SECTOR_FREE:
				/* no modification of a sector should follow a free sector */
				goto the_end;
			case SECTOR_DELETED:
				lastgoodEUN = BLOCK_NIL;
				break;
			case SECTOR_USED:
				lastgoodEUN = thisEUN;
				break;
			case SECTOR_IGNORE:
				break;
			default:
				printk("Unknown status for block %ld in EUN %d: %x\n",
				       block, thisEUN, status);
				break;
			}

			if (!silly--) {
				printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%lx\n",
				       block / (nftl->EraseSize / 512));
				return 1;
			}
			thisEUN = nftl->ReplUnitTable[thisEUN];
		}
	}

 the_end:
	if (lastgoodEUN == BLOCK_NIL) {
		/* the requested block is not on the media, return all 0x00 */
		memset(buffer, 0, 512);
	} else {
		loff_t ptr = (lastgoodEUN * nftl->EraseSize) + blockofs;
		size_t retlen;
		int res = mtd_read(mtd, ptr, 512, &retlen, buffer);

		if (res < 0 && !mtd_is_bitflip(res))
			return -EIO;
	}
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
274
85.36%
2
25.00%
thomas gleixner
thomas gleixner
25
7.79%
3
37.50%
david woodhouse
david woodhouse
17
5.30%
1
12.50%
brian norris
brian norris
4
1.25%
1
12.50%
artem bityutskiy
artem bityutskiy
1
0.31%
1
12.50%
Total
321
100.00%
8
100.00%



static int nftl_getgeo(struct mtd_blktrans_dev *dev,  struct hd_geometry *geo)
{
	struct NFTLrecord *nftl = (void *)dev;

	geo->heads = nftl->heads;
	geo->sectors = nftl->sectors;
	geo->cylinders = nftl->cylinders;

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
33
61.11%
2
40.00%
david woodhouse
david woodhouse
19
35.19%
2
40.00%
al viro
al viro
2
3.70%
1
20.00%
Total
54
100.00%
5
100.00%

/****************************************************************************
 *
 * Module stuff
 *
 ****************************************************************************/



static struct mtd_blktrans_ops nftl_tr = {
	.name		= "nftl",
	.major		= NFTL_MAJOR,
	.part_bits	= NFTL_PARTN_BITS,
	.blksize 	= 512,
	.getgeo		= nftl_getgeo,
	.readsect	= nftl_readblock,
#ifdef CONFIG_NFTL_RW
	.writesect	= nftl_writeblock,
#endif
	.add_mtd	= nftl_add_mtd,
	.remove_dev	= nftl_remove_dev,
	.owner		= THIS_MODULE,
};



static int __init init_nftl(void)
{
	return register_mtd_blktrans(&nftl_tr);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
13
81.25%
2
50.00%
david woodhouse
david woodhouse
3
18.75%
2
50.00%
Total
16
100.00%
4
100.00%



static void __exit cleanup_nftl(void)
{
	deregister_mtd_blktrans(&nftl_tr);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
11
73.33%
1
25.00%
david woodhouse
david woodhouse
2
13.33%
1
25.00%
linus torvalds
linus torvalds
1
6.67%
1
25.00%
al viro
al viro
1
6.67%
1
25.00%
Total
15
100.00%
4
100.00%


module_init(init_nftl);

module_exit(cleanup_nftl);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
MODULE_DESCRIPTION("Support code for NAND Flash Translation Layer, used on M-Systems DiskOnChip 2000 and Millennium");

MODULE_ALIAS_BLOCKDEV_MAJOR(NFTL_MAJOR);
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
pre-git
pre-git
2546
75.04%
2
5.13%
thomas gleixner
thomas gleixner
346
10.20%
4
10.26%
david woodhouse
david woodhouse
286
8.43%
5
12.82%
linus torvalds
linus torvalds
84
2.48%
5
12.82%
dimitri gorokhovik
dimitri gorokhovik
34
1.00%
2
5.13%
al viro
al viro
27
0.80%
5
12.82%
brian norris
brian norris
22
0.65%
3
7.69%
scott james remnant
scott james remnant
8
0.24%
1
2.56%
julia lawall
julia lawall
8
0.24%
1
2.56%
artem bityutskiy
artem bityutskiy
6
0.18%
3
7.69%
adrian hunter
adrian hunter
6
0.18%
1
2.56%
richard purdie
richard purdie
5
0.15%
1
2.56%
art haas
art haas
4
0.12%
1
2.56%
huang shijie
huang shijie
4
0.12%
1
2.56%
frederik deweerdt
frederik deweerdt
3
0.09%
1
2.56%
vitaly wool
vitaly wool
2
0.06%
1
2.56%
burman yan
burman yan
1
0.03%
1
2.56%
jens axboe
jens axboe
1
0.03%
1
2.56%
Total
3393
100.00%
39
100.00%
  
Directory: drivers/mtd

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.