patch-2.4.6 linux/drivers/mtd/nftl.c

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diff -u --recursive --new-file v2.4.5/linux/drivers/mtd/nftl.c linux/drivers/mtd/nftl.c
@@ -1,1108 +0,0 @@
-/* Linux driver for NAND Flash Translation Layer      */
-/* (c) 1999 Machine Vision Holdings, Inc.             */
-/* Author: David Woodhouse <dwmw2@infradead.org>      */
-/* $Id: nftl.c,v 1.57 2000/12/01 17:51:54 dwmw2 Exp $ */
-
-/*
-  The contents of this file are distributed under the GNU General
-  Public License version 2 ("GPL"). The author places no additional
-  restrictions of any kind on it. However, local legislation in some
-  countries may restrict the use of the algorithms implemented by this
-  code in certain circumstances.
-
-  The legal note below refers only to the _use_ of the code in the 
-  affected jurisdictions, and does not in any way affect the copying,
-  distribution and modification of this code, which are permitted, and
-  indeed required, under the terms of the GPL.
-
-  Section 0 of the GPL says:
- "Activities other than copying, distribution and modification are not
-  covered by this License; they are outside its scope."
-
-  You may copy, distribute and modify this code to your hearts'
-  content - it's just that in some jurisdictions, you may only _use_
-  it under the terms of the patent grant below. This puts it in a
-  similar situation to the ISDN code, which you may need telco
-  approval to use, and indeed any code which has uses that may be
-  restricted in law. For example, certain malicious uses of the
-  networking stack may be illegal, but that doesn't prevent the
-  networking code from being under GPL.
-
-  In fact the ISDN case is worse than this, because modification of
-  the code automatically invalidates its approval. Modification,
-  unlike usage, _is_ one of the rights which is protected by the
-  GPL. Happily, the law in those places where approval is required
-  doesn't actually prevent you from modifying the code - it's just
-  that you may not be allowed to _use_ it once you've done so - and
-  because usage isn't addressed by the GPL, that's just fine.
-
-  dwmw2@infradead.org
-  30/10/0
-
-  LEGAL NOTE: The NFTL format is patented by M-Systems.  They have
-  granted a licence for its use with their DiskOnChip products:
-
-    "M-Systems grants a royalty-free, non-exclusive license under
-    any presently existing M-Systems intellectual property rights
-    necessary for the design and development of NFTL-compatible
-    drivers, file systems and utilities to use the data formats with, 
-    and solely to support, M-Systems' DiskOnChip products"
-
-  A signed copy of this agreement from M-Systems is kept on file by
-  Red Hat UK Limited. In the unlikely event that you need access to it,
-  please contact dwmw2@redhat.com for assistance.  */
-
-#define PRERELEASE
-
-#include <linux/config.h>
-#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/blkpg.h>
-#ifdef CONFIG_KMOD
-#include <linux/kmod.h>
-#endif
-#include <linux/mtd/mtd.h>
-#include <linux/mtd/nftl.h>
-#include <linux/mtd/compatmac.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
-
-/* NFTL block device stuff */
-#define MAJOR_NR NFTL_MAJOR
-#define DEVICE_REQUEST nftl_request
-#define DEVICE_OFF(device)
-
-
-#include <linux/blk.h>
-#include <linux/hdreg.h>
-
-/* Linux-specific block device functions */
-
-/* I _HATE_ the Linux block device setup more than anything else I've ever
- *  encountered, except ...
- */
-
-static int nftl_sizes[256] = {0,};
-static int nftl_blocksizes[256] = {0,};
-
-/* .. for the Linux partition table handling. */
-struct hd_struct part_table[256] = {{0,0},};
-
-#if LINUX_VERSION_CODE < 0x20328
-static void dummy_init (struct gendisk *crap)
-{}
-#endif
-
-static struct gendisk nftl_gendisk = {
-        MAJOR_NR,     /* Major number */      
-        "nftl",          /* Major name */
-        4,              /* Bits to shift to get real from partition */
-        15,             /* Number of partitions per real */
-#if LINUX_VERSION_CODE < 0x20328
-        MAX_NFTLS,      /* maximum number of real */
-        dummy_init,     /* init function */
-#endif
-        part_table,     /* hd struct */
-        nftl_sizes,     /* block sizes */
-        0,              /* number */
-        NULL,           /* internal use, not presently used */
-        NULL            /* next */
-};
-
-struct NFTLrecord *NFTLs[MAX_NFTLS] = {NULL};
-
-static void NFTL_setup(struct mtd_info *mtd)
-{
-	int i;
-	struct NFTLrecord *nftl;
-	unsigned long temp;
-	int firstfree = -1;
-
-	DEBUG(MTD_DEBUG_LEVEL1,"NFTL_setup\n");
-
-	for (i = 0; i < MAX_NFTLS; i++) {
-		if (!NFTLs[i] && firstfree == -1)
-			firstfree = i;
-		else if (NFTLs[i] && NFTLs[i]->mtd == mtd) {
-			/* This is a Spare Media Header for an NFTL we've already found */
-			DEBUG(MTD_DEBUG_LEVEL1, "MTD already mounted as NFTL\n");
-			return;
-		}
-	}
-        if (firstfree == -1) {
-		printk(KERN_WARNING "No more NFTL slot available\n");
-		return;
-        }
-
-	nftl = kmalloc(sizeof(struct NFTLrecord), GFP_KERNEL);
-	if (!nftl) {
-		printk(KERN_WARNING "Out of memory for NFTL data structures\n");
-		return;
-	}
-
-	init_MUTEX(&nftl->mutex);
-
-        /* get physical parameters */
-	nftl->EraseSize = mtd->erasesize;
-        nftl->nb_blocks = mtd->size / mtd->erasesize;
-	nftl->mtd = mtd;
-
-        if (NFTL_mount(nftl) < 0) {
-		printk(KERN_WARNING "Could not mount NFTL device\n");
-		kfree(nftl);
-		return;
-        }
-
-	/* OK, it's a new one. Set up all the data structures. */
-#ifdef PSYCHO_DEBUG
-	printk("Found new NFTL nftl%c\n", firstfree + 'a');
-#endif
-
-        /* linux stuff */
-	nftl->usecount = 0;
-	nftl->cylinders = 1024;
-	nftl->heads = 16;
-
-	temp = nftl->cylinders * nftl->heads;
-	nftl->sectors = nftl->nr_sects / temp;
-	if (nftl->nr_sects % temp) {
-		nftl->sectors++;
-		temp = nftl->cylinders * nftl->sectors;
-		nftl->heads = nftl->nr_sects / temp;
-
-		if (nftl->nr_sects % temp) {
-			nftl->heads++;
-			temp = nftl->heads * nftl->sectors;
-			nftl->cylinders = nftl->nr_sects / temp;
-		}
-	}
-
-	if (nftl->nr_sects != nftl->heads * nftl->cylinders * nftl->sectors) {
-		printk(KERN_WARNING "Cannot calculate an NFTL geometry to "
-		       "match size of 0x%lx.\n", nftl->nr_sects);
-		printk(KERN_WARNING "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 );
-
-		/* Oh no we don't have nftl->nr_sects = nftl->heads * nftl->cylinders * nftl->sectors; */
-	}
-	NFTLs[firstfree] = nftl;
-	/* Finally, set up the block device sizes */
-	nftl_sizes[firstfree * 16] = nftl->nr_sects;
-	//nftl_blocksizes[firstfree*16] = 512;
-	part_table[firstfree * 16].nr_sects = nftl->nr_sects;
-
-	/* partition check ... */
-#if LINUX_VERSION_CODE < 0x20328
-	resetup_one_dev(&nftl_gendisk, firstfree);
-#else
-	grok_partitions(&nftl_gendisk, firstfree, 1<<4, nftl->nr_sects);
-#endif
-}
-
-static void NFTL_unsetup(int i)
-{
-	struct NFTLrecord *nftl = NFTLs[i];
-
-	DEBUG(MTD_DEBUG_LEVEL1, "NFTL_unsetup %d\n", i);
-	
-	NFTLs[i] = NULL;
-	
-	if (nftl->ReplUnitTable)
-		kfree(nftl->ReplUnitTable);
-	if (nftl->EUNtable)
-		kfree(nftl->EUNtable);
-		      
-	kfree(nftl);
-}
-
-/* Search the MTD device for NFTL partitions */
-static void NFTL_notify_add(struct mtd_info *mtd)
-{
-	DEBUG(MTD_DEBUG_LEVEL1, "NFTL_notify_add for %s\n", mtd->name);
-
-	if (mtd) {
-		if (!mtd->read_oob) {
-			/* If this MTD doesn't have out-of-band data,
-			   then there's no point continuing */
-			DEBUG(MTD_DEBUG_LEVEL1, "No OOB data, quitting\n");
-			return;
-		}
-		DEBUG(MTD_DEBUG_LEVEL3, "mtd->read = %p, size = %d, erasesize = %d\n", 
-		      mtd->read, mtd->size, mtd->erasesize);
-
-                NFTL_setup(mtd);
-	}
-}
-
-static void NFTL_notify_remove(struct mtd_info *mtd)
-{
-	int i;
-
-	for (i = 0; i < MAX_NFTLS; i++) {
-		if (NFTLs[i] && NFTLs[i]->mtd == mtd)
-			NFTL_unsetup(i);
-	}
-}
-
-#ifdef CONFIG_NFTL_RW
-
-/* 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 = -1;
-
-	/* Normally, we force a fold to happen before we run out of free blocks completely */
-	if (!desperate && nftl->numfreeEUNs < 2) {
-		DEBUG(MTD_DEBUG_LEVEL1, "NFTL_findfreeblock: there are too few free EUNs\n");
-		return 0xffff;
-	}
-
-	/* 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 0xffff;
-		}
-	} while (pot != nftl->LastFreeEUN);
-
-	return 0xffff;
-}
-
-static u16 NFTL_foldchain (struct NFTLrecord *nftl, unsigned thisVUC, unsigned pendingblock )
-{
-	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 ++) {
-			MTD_READOOB(nftl->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) {
-                                        DEBUG(MTD_DEBUG_LEVEL1, 
-                                              "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_IGNORE:
-			case SECTOR_DELETED:
-				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 are either 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] != targetEUN) {
-				DEBUG(MTD_DEBUG_LEVEL1, "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) {
-			DEBUG(MTD_DEBUG_LEVEL1, "Pending write not free in EUN %d. "
-			      "Folding out of place.\n", targetEUN);
-			inplace = 0;
-		}
-	}
-	
-	if (!inplace) {
-		DEBUG(MTD_DEBUG_LEVEL1, "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;
-            MTD_WRITEOOB(nftl->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.
-	*/
-	DEBUG(MTD_DEBUG_LEVEL1,"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_READECC(nftl->mtd, (nftl->EraseSize * BlockMap[block])
-                                  + (block * 512), 512, &retlen, movebuf, (char *)&oob); 
-                if (ret < 0) {
-                    ret = MTD_READECC(nftl->mtd, (nftl->EraseSize * BlockMap[block])
-                                      + (block * 512), 512, &retlen,
-                                      movebuf, (char *)&oob); 
-                    if (ret != -EIO) 
-                        printk("Error went away on retry.\n");
-                }
-                MTD_WRITEECC(nftl->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 = 0xffff;
-        
-        MTD_WRITEOOB(nftl->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];
-	DEBUG(MTD_DEBUG_LEVEL1,"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
-			 * FixMe: Update Bad Unit Table on disk
-			 */
-			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;
-}
-
-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 < 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 0xffff;
-	}
-
-	return NFTL_foldchain (nftl, LongestChain, pendingblock);
-}
-
-/* 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);
-	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;
-
-			MTD_READOOB(nftl->mtd, (writeEUN * nftl->EraseSize) + blockofs,
-				    8, &retlen, (char *)&bci);
-			
-			DEBUG(MTD_DEBUG_LEVEL2, "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 0xffff;
-			}
-
-			/* 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, 0xffff);
-			
-			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 */
-		MTD_READOOB(nftl->mtd, writeEUN * nftl->EraseSize + 8, 8,
-			    &retlen, (char *)&oob.u);
-
-		oob.u.a.VirtUnitNum = oob.u.a.SpareVirtUnitNum = cpu_to_le16(thisVUC);
-
-		MTD_WRITEOOB(nftl->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 */
-			MTD_READOOB(nftl->mtd, (lastEUN * nftl->EraseSize) + 8,
-				    8, &retlen, (char *)&oob.u);
-
-			oob.u.a.ReplUnitNum = oob.u.a.SpareReplUnitNum
-				= cpu_to_le16(writeEUN);
-
-			MTD_WRITEOOB(nftl->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 0xffff;
-}
-
-static int NFTL_writeblock(struct NFTLrecord *nftl, unsigned block, char *buffer)
-{
-	u16 writeEUN;
-	unsigned long blockofs = (block * 512) & (nftl->EraseSize - 1);
-	size_t retlen;
-	u8 eccbuf[6];
-
-	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;
-	}
-
-	MTD_WRITEECC(nftl->mtd, (writeEUN * nftl->EraseSize) + blockofs,
-		     512, &retlen, (char *)buffer, (char *)eccbuf);
-        /* no need to write SECTOR_USED flags since they are written in mtd_writeecc */
-
-	return 0;
-}
-#endif /* CONFIG_NFTL_RW */
-
-static int NFTL_readblock(struct NFTLrecord *nftl, unsigned block, char *buffer)
-{
-	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 (MTD_READOOB(nftl->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 %d in EUN %d: %x\n",
-				       block, thisEUN, status);
-				break;
-			}
-
-			if (!silly--) {
-				printk(KERN_WARNING "Infinite loop in Virtual Unit Chain 0x%x\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;
-		u_char eccbuf[6];
-		if (MTD_READECC(nftl->mtd, ptr, 512, &retlen, buffer, eccbuf))
-			return -EIO;
-	}
-	return 0;
-}
-
-static int nftl_ioctl(struct inode * inode, struct file * file, unsigned int cmd, unsigned long arg)
-{
-	struct NFTLrecord *nftl;
-
-	nftl = NFTLs[MINOR(inode->i_rdev) / 16];
-
-	if (!nftl) return -EINVAL;
-
-	switch (cmd) {
-	case HDIO_GETGEO: {
-		struct hd_geometry g;
-
-		g.heads = nftl->heads;
-		g.sectors = nftl->sectors;
-		g.cylinders = nftl->cylinders;
-		g.start = part_table[MINOR(inode->i_rdev)].start_sect;
-		return copy_to_user((void *)arg, &g, sizeof g) ? -EFAULT : 0;
-	}
-	case BLKGETSIZE:   /* Return device size */
-		if (!arg) return -EINVAL;
-		return put_user(part_table[MINOR(inode->i_rdev)].nr_sects,
-                                (long *) arg);
-		
-	case BLKFLSBUF:
-		if (!capable(CAP_SYS_ADMIN)) return -EACCES;
-		fsync_dev(inode->i_rdev);
-		invalidate_buffers(inode->i_rdev);
-		if (nftl->mtd->sync)
-			nftl->mtd->sync(nftl->mtd);
-		return 0;
-
-	case BLKRRPART:
-		if (!capable(CAP_SYS_ADMIN)) return -EACCES;
-		if (nftl->usecount > 1) return -EBUSY;
-#if LINUX_VERSION_CODE < 0x20328
-		resetup_one_dev(&nftl_gendisk, MINOR(inode->i_rdev) / 16);
-#else
-		grok_partitions(&nftl_gendisk, MINOR(inode->i_rdev) / 16,
-				1<<4, nftl->nr_sects);
-#endif
-		return 0;
-
-#if (LINUX_VERSION_CODE < 0x20303)		
-	RO_IOCTLS(inode->i_rdev, arg);  /* ref. linux/blk.h */
-#else
-	case BLKROSET:
-	case BLKROGET:
-	case BLKSSZGET:
-		return blk_ioctl(inode->i_rdev, cmd, arg);
-#endif
-
-	default:
-		return -EINVAL;
-	}
-}
-
-void nftl_request(RQFUNC_ARG)
-{
-	unsigned int dev, block, nsect;
-	struct NFTLrecord *nftl;
-	char *buffer;
-	struct request *req;
-	int res;
-
-	while (1) {
-		INIT_REQUEST;	/* blk.h */
-		req = CURRENT;
-		
-		/* We can do this because the generic code knows not to
-		   touch the request at the head of the queue */
-		spin_unlock_irq(&io_request_lock);
-
-		DEBUG(MTD_DEBUG_LEVEL2, "NFTL_request\n");
-		DEBUG(MTD_DEBUG_LEVEL3, "NFTL %s request, from sector 0x%04lx for 0x%04lx sectors\n",
-		      (req->cmd == READ) ? "Read " : "Write",
-		      req->sector, req->current_nr_sectors);
-
-		dev = MINOR(req->rq_dev);
-		block = req->sector;
-		nsect = req->current_nr_sectors;
-		buffer = req->buffer;
-		res = 1; /* succeed */
-
-		if (dev >= MAX_NFTLS * 16) {
-			/* there is no such partition */
-			printk("nftl: bad minor number: device = %s\n",
-			       kdevname(req->rq_dev));
-			res = 0; /* fail */
-			goto repeat;
-		}
-		
-		nftl = NFTLs[dev / 16];
-		DEBUG(MTD_DEBUG_LEVEL3, "Waiting for mutex\n");
-		down(&nftl->mutex);
-		DEBUG(MTD_DEBUG_LEVEL3, "Got mutex\n");
-
-		if (block + nsect > part_table[dev].nr_sects) {
-			/* access past the end of device */
-			printk("nftl%c%d: bad access: block = %d, count = %d\n",
-			       (MINOR(req->rq_dev)>>6)+'a', dev & 0xf, block, nsect);
-			up(&nftl->mutex);
-			res = 0; /* fail */
-			goto repeat;
-		}
-		
-		block += part_table[dev].start_sect;
-		
-		if (req->cmd == READ) {
-			DEBUG(MTD_DEBUG_LEVEL2, "NFTL read request of 0x%x sectors @ %x "
-			      "(req->nr_sectors == %lx)\n", nsect, block, req->nr_sectors);
-	
-			for ( ; nsect > 0; nsect-- , block++, buffer += 512) {
-				/* Read a single sector to req->buffer + (512 * i) */
-				if (NFTL_readblock(nftl, block, buffer)) {
-					DEBUG(MTD_DEBUG_LEVEL2, "NFTL read request failed\n");
-					up(&nftl->mutex);
-					res = 0;
-					goto repeat;
-				}
-			}
-
-			DEBUG(MTD_DEBUG_LEVEL2,"NFTL read request completed OK\n");
-			up(&nftl->mutex);
-			goto repeat;
-		} else if (req->cmd == WRITE) {
-			DEBUG(MTD_DEBUG_LEVEL2, "NFTL write request of 0x%x sectors @ %x "
-			      "(req->nr_sectors == %lx)\n", nsect, block,
-			      req->nr_sectors);
-#ifdef CONFIG_NFTL_RW
-			for ( ; nsect > 0; nsect-- , block++, buffer += 512) {
-				/* Read a single sector to req->buffer + (512 * i) */
-				if (NFTL_writeblock(nftl, block, buffer)) {
-					DEBUG(MTD_DEBUG_LEVEL1,"NFTL write request failed\n");
-					up(&nftl->mutex);
-					res = 0;
-					goto repeat;
-				}
-			}
-			DEBUG(MTD_DEBUG_LEVEL2,"NFTL write request completed OK\n");
-#else
-			res = 0; /* Writes always fail */
-#endif /* CONFIG_NFTL_RW */
-			up(&nftl->mutex);
-			goto repeat;
-		} else {
-			DEBUG(MTD_DEBUG_LEVEL0, "NFTL unknown request\n");
-			up(&nftl->mutex);
-			res = 0;
-			goto repeat;
-		}
-	repeat: 
-		DEBUG(MTD_DEBUG_LEVEL3, "end_request(%d)\n", res);
-		spin_lock_irq(&io_request_lock);
-		end_request(res);
-	}
-}
-
-static int nftl_open(struct inode *ip, struct file *fp)
-{
-	int nftlnum = MINOR(ip->i_rdev) / 16;
-	struct NFTLrecord *thisNFTL;
-	thisNFTL = NFTLs[nftlnum];
-
-	DEBUG(MTD_DEBUG_LEVEL2,"NFTL_open\n");
-
-#ifdef CONFIG_KMOD
-	if (!thisNFTL && nftlnum == 0) {
-		request_module("docprobe");
-		thisNFTL = NFTLs[nftlnum];
-	}
-#endif
-	if (!thisNFTL) {
-		DEBUG(MTD_DEBUG_LEVEL2,"ENODEV: thisNFTL = %d, minor = %d, ip = %p, fp = %p\n", 
-		      nftlnum, ip->i_rdev, ip, fp);
-		return -ENODEV;
-	}
-
-#ifndef CONFIG_NFTL_RW
-	if (fp->f_mode & FMODE_WRITE)
-		return -EROFS;
-#endif /* !CONFIG_NFTL_RW */
-
-	thisNFTL->usecount++;
-	MOD_INC_USE_COUNT;
-	if (!get_mtd_device(thisNFTL->mtd, -1)) {
-		MOD_DEC_USE_COUNT;
-		return /* -E'SBUGGEREDOFF */ -ENXIO;
-	}
-
-	return 0;
-}
-
-static int nftl_release(struct inode *inode, struct file *fp)
-{
-	struct NFTLrecord *thisNFTL;
-
-	thisNFTL = NFTLs[MINOR(inode->i_rdev) / 16];
-
-	DEBUG(MTD_DEBUG_LEVEL2, "NFTL_release\n");
-
-	invalidate_device(inode->i_rdev, 1);
-
-	if (thisNFTL->mtd->sync)
-		thisNFTL->mtd->sync(thisNFTL->mtd);
-	thisNFTL->usecount--;
-	MOD_DEC_USE_COUNT;
-
-	put_mtd_device(thisNFTL->mtd);
-
-	return 0;
-}
-#if LINUX_VERSION_CODE < 0x20326
-static struct file_operations nftl_fops = {
-	read:		block_read,
-	write:		block_write,
-	ioctl:		nftl_ioctl,
-	open:		nftl_open,
-	release:	nftl_release,
-	fsync:		block_fsync,
-};
-#else
-static struct block_device_operations nftl_fops = 
-{
-	open:		nftl_open,
-	release:	nftl_release,
-	ioctl: 		nftl_ioctl
-};
-#endif
-
-
-
-/****************************************************************************
- *
- * Module stuff
- *
- ****************************************************************************/
-
-#if LINUX_VERSION_CODE < 0x20212 && defined(MODULE)
-#define init_nftl init_module
-#define cleanup_nftl cleanup_module
-#endif
-
-static struct mtd_notifier nftl_notifier = {NFTL_notify_add, NFTL_notify_remove, NULL};
-
-/* static int __init init_nftl(void) */
-int __init init_nftl(void)
-{
-	int i;
-
-	printk(KERN_NOTICE
-	       "M-Systems NAND Flash Translation Layer driver. (C) 1999 MVHI\n");
-#ifdef PRERELEASE 
-	printk(KERN_INFO"$Id: nftl.c,v 1.57 2000/12/01 17:51:54 dwmw2 Exp $\n");
-#endif
-
-	if (register_blkdev(MAJOR_NR, "nftl", &nftl_fops)){
-		printk("unable to register NFTL block device on major %d\n", MAJOR_NR);
-		return -EBUSY;
-	} else {
-#if LINUX_VERSION_CODE < 0x20320
-		blk_dev[MAJOR_NR].request_fn = nftl_request;
-#else
-		blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), &nftl_request);
-#endif
-		/* set block size to 1kB each */
-		for (i = 0; i < 256; i++) {
-			nftl_blocksizes[i] = 1024;
-		}
-		blksize_size[MAJOR_NR] = nftl_blocksizes;
-
-		nftl_gendisk.next = gendisk_head;
-		gendisk_head = &nftl_gendisk;
-	}
-	
-	register_mtd_user(&nftl_notifier);
-
-	return 0;
-}
-
-static void __exit cleanup_nftl(void)
-{
-	struct gendisk *gd, **gdp;
-
-  	unregister_mtd_user(&nftl_notifier);
-  	unregister_blkdev(MAJOR_NR, "nftl");
-  	
-#if LINUX_VERSION_CODE < 0x20320
-  	blk_dev[MAJOR_NR].request_fn = 0;
-#else
-  	blk_cleanup_queue(BLK_DEFAULT_QUEUE(MAJOR_NR));
-#endif	
-
-	/* remove ourself from generic harddisk list
-	   FIXME: why can't I found this partition on /proc/partition */
-  	for (gdp = &gendisk_head; *gdp; gdp = &((*gdp)->next))
-    		if (*gdp == &nftl_gendisk) {
-      			gd = *gdp; *gdp = gd->next;
-      			break;
-    	}
-}
-
-module_init(init_nftl);
-module_exit(cleanup_nftl);

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)