Merge branch 'master' of /home/tglx/work/mtd/git/linux-2.6.git/
[sfrench/cifs-2.6.git] / drivers / mtd / inftlmount.c
1 /* 
2  * inftlmount.c -- INFTL mount code with extensive checks.
3  *
4  * Author: Greg Ungerer (gerg@snapgear.com)
5  * (C) Copyright 2002-2003, Greg Ungerer (gerg@snapgear.com)
6  *
7  * Based heavily on the nftlmount.c code which is:
8  * Author: Fabrice Bellard (fabrice.bellard@netgem.com) 
9  * Copyright (C) 2000 Netgem S.A.
10  *
11  * $Id: inftlmount.c,v 1.16 2004/11/22 13:50:53 kalev Exp $
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
26  */
27
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <asm/errno.h>
31 #include <asm/io.h>
32 #include <asm/uaccess.h>
33 #include <linux/miscdevice.h>
34 #include <linux/pci.h>
35 #include <linux/delay.h>
36 #include <linux/slab.h>
37 #include <linux/sched.h>
38 #include <linux/init.h>
39 #include <linux/mtd/mtd.h>
40 #include <linux/mtd/nftl.h>
41 #include <linux/mtd/inftl.h>
42 #include <linux/mtd/compatmac.h>
43
44 char inftlmountrev[]="$Revision: 1.16 $";
45
46 /*
47  * find_boot_record: Find the INFTL Media Header and its Spare copy which
48  *      contains the various device information of the INFTL partition and
49  *      Bad Unit Table. Update the PUtable[] table according to the Bad
50  *      Unit Table. PUtable[] is used for management of Erase Unit in
51  *      other routines in inftlcore.c and inftlmount.c.
52  */
53 static int find_boot_record(struct INFTLrecord *inftl)
54 {
55         struct inftl_unittail h1;
56         //struct inftl_oob oob;
57         unsigned int i, block;
58         u8 buf[SECTORSIZE];
59         struct INFTLMediaHeader *mh = &inftl->MediaHdr;
60         struct INFTLPartition *ip;
61         size_t retlen;
62
63         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: find_boot_record(inftl=%p)\n", inftl);
64
65         /*
66          * Assume logical EraseSize == physical erasesize for starting the
67          * scan. We'll sort it out later if we find a MediaHeader which says
68          * otherwise.
69          */
70         inftl->EraseSize = inftl->mbd.mtd->erasesize;
71         inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
72
73         inftl->MediaUnit = BLOCK_NIL;
74
75         /* Search for a valid boot record */
76         for (block = 0; block < inftl->nb_blocks; block++) {
77                 int ret;
78
79                 /*
80                  * Check for BNAND header first. Then whinge if it's found
81                  * but later checks fail.
82                  */
83                 ret = MTD_READ(inftl->mbd.mtd, block * inftl->EraseSize,
84                     SECTORSIZE, &retlen, buf);
85                 /* We ignore ret in case the ECC of the MediaHeader is invalid
86                    (which is apparently acceptable) */
87                 if (retlen != SECTORSIZE) {
88                         static int warncount = 5;
89
90                         if (warncount) {
91                                 printk(KERN_WARNING "INFTL: block read at 0x%x "
92                                         "of mtd%d failed: %d\n",
93                                         block * inftl->EraseSize,
94                                         inftl->mbd.mtd->index, ret);
95                                 if (!--warncount)
96                                         printk(KERN_WARNING "INFTL: further "
97                                                 "failures for this block will "
98                                                 "not be printed\n");
99                         }
100                         continue;
101                 }
102
103                 if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
104                         /* BNAND\0 not found. Continue */
105                         continue;
106                 }
107
108                 /* To be safer with BIOS, also use erase mark as discriminant */
109                 if ((ret = MTD_READOOB(inftl->mbd.mtd, block * inftl->EraseSize +
110                     SECTORSIZE + 8, 8, &retlen, (char *)&h1) < 0)) {
111                         printk(KERN_WARNING "INFTL: ANAND header found at "
112                                 "0x%x in mtd%d, but OOB data read failed "
113                                 "(err %d)\n", block * inftl->EraseSize,
114                                 inftl->mbd.mtd->index, ret);
115                         continue;
116                 }
117
118
119                 /*
120                  * This is the first we've seen.
121                  * Copy the media header structure into place.
122                  */
123                 memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
124
125                 /* Read the spare media header at offset 4096 */
126                 MTD_READ(inftl->mbd.mtd, block * inftl->EraseSize + 4096,
127                     SECTORSIZE, &retlen, buf);
128                 if (retlen != SECTORSIZE) {
129                         printk(KERN_WARNING "INFTL: Unable to read spare "
130                                "Media Header\n");
131                         return -1;
132                 }
133                 /* Check if this one is the same as the first one we found. */
134                 if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
135                         printk(KERN_WARNING "INFTL: Primary and spare Media "
136                                "Headers disagree.\n");
137                         return -1;
138                 }
139
140                 mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
141                 mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
142                 mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
143                 mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
144                 mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
145                 mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
146
147 #ifdef CONFIG_MTD_DEBUG_VERBOSE
148                 if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
149                         printk("INFTL: Media Header ->\n"
150                                 "    bootRecordID          = %s\n"
151                                 "    NoOfBootImageBlocks   = %d\n"
152                                 "    NoOfBinaryPartitions  = %d\n"
153                                 "    NoOfBDTLPartitions    = %d\n"
154                                 "    BlockMultiplerBits    = %d\n"
155                                 "    FormatFlgs            = %d\n"
156                                 "    OsakVersion           = 0x%x\n"
157                                 "    PercentUsed           = %d\n",
158                                 mh->bootRecordID, mh->NoOfBootImageBlocks,
159                                 mh->NoOfBinaryPartitions,
160                                 mh->NoOfBDTLPartitions,
161                                 mh->BlockMultiplierBits, mh->FormatFlags,
162                                 mh->OsakVersion, mh->PercentUsed);
163                 }
164 #endif
165
166                 if (mh->NoOfBDTLPartitions == 0) {
167                         printk(KERN_WARNING "INFTL: Media Header sanity check "
168                                 "failed: NoOfBDTLPartitions (%d) == 0, "
169                                 "must be at least 1\n", mh->NoOfBDTLPartitions);
170                         return -1;
171                 }
172
173                 if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
174                         printk(KERN_WARNING "INFTL: Media Header sanity check "
175                                 "failed: Total Partitions (%d) > 4, "
176                                 "BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
177                                 mh->NoOfBinaryPartitions,
178                                 mh->NoOfBDTLPartitions,
179                                 mh->NoOfBinaryPartitions);
180                         return -1;
181                 }
182
183                 if (mh->BlockMultiplierBits > 1) {
184                         printk(KERN_WARNING "INFTL: sorry, we don't support "
185                                 "UnitSizeFactor 0x%02x\n",
186                                 mh->BlockMultiplierBits);
187                         return -1;
188                 } else if (mh->BlockMultiplierBits == 1) {
189                         printk(KERN_WARNING "INFTL: support for INFTL with "
190                                 "UnitSizeFactor 0x%02x is experimental\n",
191                                 mh->BlockMultiplierBits);
192                         inftl->EraseSize = inftl->mbd.mtd->erasesize <<
193                                 mh->BlockMultiplierBits;
194                         inftl->nb_blocks = inftl->mbd.mtd->size / inftl->EraseSize;
195                         block >>= mh->BlockMultiplierBits;
196                 }
197
198                 /* Scan the partitions */
199                 for (i = 0; (i < 4); i++) {
200                         ip = &mh->Partitions[i];
201                         ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
202                         ip->firstUnit = le32_to_cpu(ip->firstUnit);
203                         ip->lastUnit = le32_to_cpu(ip->lastUnit);
204                         ip->flags = le32_to_cpu(ip->flags);
205                         ip->spareUnits = le32_to_cpu(ip->spareUnits);
206                         ip->Reserved0 = le32_to_cpu(ip->Reserved0);
207
208 #ifdef CONFIG_MTD_DEBUG_VERBOSE
209                         if (CONFIG_MTD_DEBUG_VERBOSE >= 2) {
210                                 printk("    PARTITION[%d] ->\n"
211                                         "        virtualUnits    = %d\n"
212                                         "        firstUnit       = %d\n"
213                                         "        lastUnit        = %d\n"
214                                         "        flags           = 0x%x\n"
215                                         "        spareUnits      = %d\n",
216                                         i, ip->virtualUnits, ip->firstUnit,
217                                         ip->lastUnit, ip->flags,
218                                         ip->spareUnits);
219                         }
220 #endif
221
222                         if (ip->Reserved0 != ip->firstUnit) {
223                                 struct erase_info *instr = &inftl->instr;
224
225                                 instr->mtd = inftl->mbd.mtd;
226
227                                 /*
228                                  *      Most likely this is using the
229                                  *      undocumented qiuck mount feature.
230                                  *      We don't support that, we will need
231                                  *      to erase the hidden block for full
232                                  *      compatibility.
233                                  */
234                                 instr->addr = ip->Reserved0 * inftl->EraseSize;
235                                 instr->len = inftl->EraseSize;
236                                 MTD_ERASE(inftl->mbd.mtd, instr);
237                         }
238                         if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
239                                 printk(KERN_WARNING "INFTL: Media Header "
240                                         "Partition %d sanity check failed\n"
241                                         "    firstUnit %d : lastUnit %d  >  "
242                                         "virtualUnits %d\n", i, ip->lastUnit,
243                                         ip->firstUnit, ip->Reserved0);
244                                 return -1;
245                         }
246                         if (ip->Reserved1 != 0) {
247                                 printk(KERN_WARNING "INFTL: Media Header "
248                                         "Partition %d sanity check failed: "
249                                         "Reserved1 %d != 0\n",
250                                         i, ip->Reserved1);
251                                 return -1;
252                         }
253
254                         if (ip->flags & INFTL_BDTL)
255                                 break;
256                 }
257
258                 if (i >= 4) {
259                         printk(KERN_WARNING "INFTL: Media Header Partition "
260                                 "sanity check failed:\n       No partition "
261                                 "marked as Disk Partition\n");
262                         return -1;
263                 }
264
265                 inftl->nb_boot_blocks = ip->firstUnit;
266                 inftl->numvunits = ip->virtualUnits;
267                 if (inftl->numvunits > (inftl->nb_blocks -
268                     inftl->nb_boot_blocks - 2)) {
269                         printk(KERN_WARNING "INFTL: Media Header sanity check "
270                                 "failed:\n        numvunits (%d) > nb_blocks "
271                                 "(%d) - nb_boot_blocks(%d) - 2\n",
272                                 inftl->numvunits, inftl->nb_blocks,
273                                 inftl->nb_boot_blocks);
274                         return -1;
275                 }
276                 
277                 inftl->mbd.size  = inftl->numvunits *
278                         (inftl->EraseSize / SECTORSIZE);
279
280                 /*
281                  * Block count is set to last used EUN (we won't need to keep
282                  * any meta-data past that point).
283                  */
284                 inftl->firstEUN = ip->firstUnit;
285                 inftl->lastEUN = ip->lastUnit;
286                 inftl->nb_blocks = ip->lastUnit + 1;
287
288                 /* Memory alloc */
289                 inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
290                 if (!inftl->PUtable) {
291                         printk(KERN_WARNING "INFTL: allocation of PUtable "
292                                 "failed (%zd bytes)\n",
293                                 inftl->nb_blocks * sizeof(u16));
294                         return -ENOMEM;
295                 }
296
297                 inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
298                 if (!inftl->VUtable) {
299                         kfree(inftl->PUtable);
300                         printk(KERN_WARNING "INFTL: allocation of VUtable "
301                                 "failed (%zd bytes)\n",
302                                 inftl->nb_blocks * sizeof(u16));
303                         return -ENOMEM;
304                 }
305                 
306                 /* Mark the blocks before INFTL MediaHeader as reserved */
307                 for (i = 0; i < inftl->nb_boot_blocks; i++)
308                         inftl->PUtable[i] = BLOCK_RESERVED;
309                 /* Mark all remaining blocks as potentially containing data */
310                 for (; i < inftl->nb_blocks; i++)
311                         inftl->PUtable[i] = BLOCK_NOTEXPLORED;
312
313                 /* Mark this boot record (NFTL MediaHeader) block as reserved */
314                 inftl->PUtable[block] = BLOCK_RESERVED;
315
316                 /* Read Bad Erase Unit Table and modify PUtable[] accordingly */
317                 for (i = 0; i < inftl->nb_blocks; i++) {
318                         int physblock;
319                         /* If any of the physical eraseblocks are bad, don't
320                            use the unit. */
321                         for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
322                                 if (inftl->mbd.mtd->block_isbad(inftl->mbd.mtd, i * inftl->EraseSize + physblock))
323                                         inftl->PUtable[i] = BLOCK_RESERVED;
324                         }
325                 }
326
327                 inftl->MediaUnit = block;
328                 return 0;
329         }
330
331         /* Not found. */
332         return -1;
333 }
334
335 static int memcmpb(void *a, int c, int n)
336 {
337         int i;
338         for (i = 0; i < n; i++) {
339                 if (c != ((unsigned char *)a)[i])
340                         return 1;
341         }
342         return 0;
343 }
344
345 /*
346  * check_free_sector: check if a free sector is actually FREE,
347  *      i.e. All 0xff in data and oob area.
348  */
349 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
350         int len, int check_oob)
351 {
352         u8 buf[SECTORSIZE + inftl->mbd.mtd->oobsize];
353         size_t retlen;
354         int i;
355
356         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: check_free_sectors(inftl=%p,"
357                 "address=0x%x,len=%d,check_oob=%d)\n", inftl,
358                 address, len, check_oob);
359
360         for (i = 0; i < len; i += SECTORSIZE) {
361                 if (MTD_READECC(inftl->mbd.mtd, address, SECTORSIZE, &retlen, buf, &buf[SECTORSIZE], &inftl->oobinfo) < 0)
362                         return -1;
363                 if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
364                         return -1;
365
366                 if (check_oob) {
367                         if (memcmpb(buf + SECTORSIZE, 0xff, inftl->mbd.mtd->oobsize) != 0)
368                                 return -1;
369                 }
370                 address += SECTORSIZE;
371         }
372
373         return 0;
374 }
375
376 /*
377  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
378  *               Unit and Update INFTL metadata. Each erase operation is
379  *               checked with check_free_sectors.
380  *
381  * Return: 0 when succeed, -1 on error.
382  *
383  * ToDo: 1. Is it neceressary to check_free_sector after erasing ?? 
384  */
385 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
386 {
387         size_t retlen;
388         struct inftl_unittail uci;
389         struct erase_info *instr = &inftl->instr;
390         int physblock;
391
392         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_formatblock(inftl=%p,"
393                 "block=%d)\n", inftl, block);
394
395         memset(instr, 0, sizeof(struct erase_info));
396
397         /* FIXME: Shouldn't we be setting the 'discarded' flag to zero
398            _first_? */
399
400         /* Use async erase interface, test return code */
401         instr->mtd = inftl->mbd.mtd;
402         instr->addr = block * inftl->EraseSize;
403         instr->len = inftl->mbd.mtd->erasesize;
404         /* Erase one physical eraseblock at a time, even though the NAND api
405            allows us to group them.  This way we if we have a failure, we can
406            mark only the failed block in the bbt. */
407         for (physblock = 0; physblock < inftl->EraseSize; physblock += instr->len, instr->addr += instr->len) {
408                 MTD_ERASE(inftl->mbd.mtd, instr);
409
410                 if (instr->state == MTD_ERASE_FAILED) {
411                         printk(KERN_WARNING "INFTL: error while formatting block %d\n",
412                                 block);
413                         goto fail;
414                 }
415
416                 /*
417                 * Check the "freeness" of Erase Unit before updating metadata.
418                 * FixMe: is this check really necessary? Since we have check the
419                 *        return code after the erase operation.
420                 */
421                 if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
422                         goto fail;
423         }
424
425         uci.EraseMark = cpu_to_le16(ERASE_MARK);
426         uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
427         uci.Reserved[0] = 0;
428         uci.Reserved[1] = 0;
429         uci.Reserved[2] = 0;
430         uci.Reserved[3] = 0;
431         instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
432         if (MTD_WRITEOOB(inftl->mbd.mtd, instr->addr +
433             8, 8, &retlen, (char *)&uci) < 0)
434                 goto fail;
435         return 0;
436 fail:
437         /* could not format, update the bad block table (caller is responsible
438            for setting the PUtable to BLOCK_RESERVED on failure) */
439         inftl->mbd.mtd->block_markbad(inftl->mbd.mtd, instr->addr);
440         return -1;
441 }
442
443 /*
444  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
445  *      Units in a Virtual Unit Chain, i.e. all the units are disconnected.
446  *
447  *      Since the chain is invalid then we will have to erase it from its
448  *      head (normally for INFTL we go from the oldest). But if it has a
449  *      loop then there is no oldest...
450  */
451 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
452 {
453         unsigned int block = first_block, block1;
454
455         printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
456                 first_block);
457
458         for (;;) {
459                 block1 = inftl->PUtable[block];
460
461                 printk(KERN_WARNING "INFTL: formatting block %d\n", block);
462                 if (INFTL_formatblock(inftl, block) < 0) {
463                         /*
464                          * Cannot format !!!! Mark it as Bad Unit,
465                          */
466                         inftl->PUtable[block] = BLOCK_RESERVED;
467                 } else {
468                         inftl->PUtable[block] = BLOCK_FREE;
469                 }
470
471                 /* Goto next block on the chain */
472                 block = block1;
473
474                 if (block == BLOCK_NIL || block >= inftl->lastEUN)
475                         break;
476         }
477 }
478
479 void INFTL_dumptables(struct INFTLrecord *s)
480 {
481         int i;
482
483         printk("-------------------------------------------"
484                 "----------------------------------\n");
485
486         printk("VUtable[%d] ->", s->nb_blocks);
487         for (i = 0; i < s->nb_blocks; i++) {
488                 if ((i % 8) == 0)
489                         printk("\n%04x: ", i);
490                 printk("%04x ", s->VUtable[i]);
491         }
492
493         printk("\n-------------------------------------------"
494                 "----------------------------------\n");
495
496         printk("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
497         for (i = 0; i <= s->lastEUN; i++) {
498                 if ((i % 8) == 0)
499                         printk("\n%04x: ", i);
500                 printk("%04x ", s->PUtable[i]);
501         }
502
503         printk("\n-------------------------------------------"
504                 "----------------------------------\n");
505
506         printk("INFTL ->\n"
507                 "  EraseSize       = %d\n"
508                 "  h/s/c           = %d/%d/%d\n"
509                 "  numvunits       = %d\n"
510                 "  firstEUN        = %d\n"
511                 "  lastEUN         = %d\n"
512                 "  numfreeEUNs     = %d\n"
513                 "  LastFreeEUN     = %d\n"
514                 "  nb_blocks       = %d\n"
515                 "  nb_boot_blocks  = %d",
516                 s->EraseSize, s->heads, s->sectors, s->cylinders,
517                 s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
518                 s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
519
520         printk("\n-------------------------------------------"
521                 "----------------------------------\n");
522 }
523
524 void INFTL_dumpVUchains(struct INFTLrecord *s)
525 {
526         int logical, block, i;
527
528         printk("-------------------------------------------"
529                 "----------------------------------\n");
530
531         printk("INFTL Virtual Unit Chains:\n");
532         for (logical = 0; logical < s->nb_blocks; logical++) {
533                 block = s->VUtable[logical];
534                 if (block > s->nb_blocks)
535                         continue;
536                 printk("  LOGICAL %d --> %d ", logical, block);
537                 for (i = 0; i < s->nb_blocks; i++) {
538                         if (s->PUtable[block] == BLOCK_NIL)
539                                 break;
540                         block = s->PUtable[block];
541                         printk("%d ", block);
542                 }
543                 printk("\n");
544         }
545
546         printk("-------------------------------------------"
547                 "----------------------------------\n");
548 }
549
550 int INFTL_mount(struct INFTLrecord *s)
551 {
552         unsigned int block, first_block, prev_block, last_block;
553         unsigned int first_logical_block, logical_block, erase_mark;
554         int chain_length, do_format_chain;
555         struct inftl_unithead1 h0;
556         struct inftl_unittail h1;
557         size_t retlen;
558         int i;
559         u8 *ANACtable, ANAC;
560
561         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_mount(inftl=%p)\n", s);
562
563         /* Search for INFTL MediaHeader and Spare INFTL Media Header */
564         if (find_boot_record(s) < 0) {
565                 printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
566                 return -1;
567         }
568
569         /* Init the logical to physical table */
570         for (i = 0; i < s->nb_blocks; i++)
571                 s->VUtable[i] = BLOCK_NIL;
572
573         logical_block = block = BLOCK_NIL;
574
575         /* Temporary buffer to store ANAC numbers. */
576         ANACtable = kmalloc(s->nb_blocks * sizeof(u8), GFP_KERNEL);
577         memset(ANACtable, 0, s->nb_blocks);
578
579         /*
580          * First pass is to explore each physical unit, and construct the
581          * virtual chains that exist (newest physical unit goes into VUtable).
582          * Any block that is in any way invalid will be left in the
583          * NOTEXPLORED state. Then at the end we will try to format it and
584          * mark it as free.
585          */
586         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 1, explore each unit\n");
587         for (first_block = s->firstEUN; first_block <= s->lastEUN; first_block++) {
588                 if (s->PUtable[first_block] != BLOCK_NOTEXPLORED)
589                         continue;
590
591                 do_format_chain = 0;
592                 first_logical_block = BLOCK_NIL;
593                 last_block = BLOCK_NIL;
594                 block = first_block;
595
596                 for (chain_length = 0; ; chain_length++) {
597
598                         if ((chain_length == 0) && 
599                             (s->PUtable[block] != BLOCK_NOTEXPLORED)) {
600                                 /* Nothing to do here, onto next block */
601                                 break;
602                         }
603
604                         if (MTD_READOOB(s->mbd.mtd, block * s->EraseSize + 8,
605                             8, &retlen, (char *)&h0) < 0 ||
606                             MTD_READOOB(s->mbd.mtd, block * s->EraseSize +
607                             2 * SECTORSIZE + 8, 8, &retlen, (char *)&h1) < 0) {
608                                 /* Should never happen? */
609                                 do_format_chain++;
610                                 break;
611                         }
612
613                         logical_block = le16_to_cpu(h0.virtualUnitNo);
614                         prev_block = le16_to_cpu(h0.prevUnitNo);
615                         erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
616                         ANACtable[block] = h0.ANAC;
617
618                         /* Previous block is relative to start of Partition */
619                         if (prev_block < s->nb_blocks)
620                                 prev_block += s->firstEUN;
621
622                         /* Already explored partial chain? */
623                         if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
624                                 /* Check if chain for this logical */
625                                 if (logical_block == first_logical_block) {
626                                         if (last_block != BLOCK_NIL)
627                                                 s->PUtable[last_block] = block;
628                                 }
629                                 break;
630                         }
631
632                         /* Check for invalid block */
633                         if (erase_mark != ERASE_MARK) {
634                                 printk(KERN_WARNING "INFTL: corrupt block %d "
635                                         "in chain %d, chain length %d, erase "
636                                         "mark 0x%x?\n", block, first_block,
637                                         chain_length, erase_mark);
638                                 /*
639                                  * Assume end of chain, probably incomplete
640                                  * fold/erase...
641                                  */
642                                 if (chain_length == 0)
643                                         do_format_chain++;
644                                 break;
645                         }
646
647                         /* Check for it being free already then... */
648                         if ((logical_block == BLOCK_FREE) ||
649                             (logical_block == BLOCK_NIL)) {
650                                 s->PUtable[block] = BLOCK_FREE;
651                                 break;
652                         }
653
654                         /* Sanity checks on block numbers */
655                         if ((logical_block >= s->nb_blocks) ||
656                             ((prev_block >= s->nb_blocks) &&
657                              (prev_block != BLOCK_NIL))) {
658                                 if (chain_length > 0) {
659                                         printk(KERN_WARNING "INFTL: corrupt "
660                                                 "block %d in chain %d?\n",
661                                                 block, first_block);
662                                         do_format_chain++;
663                                 }
664                                 break;
665                         }
666
667                         if (first_logical_block == BLOCK_NIL) {
668                                 first_logical_block = logical_block;
669                         } else {
670                                 if (first_logical_block != logical_block) {
671                                         /* Normal for folded chain... */
672                                         break;
673                                 }
674                         }
675
676                         /*
677                          * Current block is valid, so if we followed a virtual
678                          * chain to get here then we can set the previous
679                          * block pointer in our PUtable now. Then move onto
680                          * the previous block in the chain.
681                          */
682                         s->PUtable[block] = BLOCK_NIL;
683                         if (last_block != BLOCK_NIL)
684                                 s->PUtable[last_block] = block;
685                         last_block = block;
686                         block = prev_block;
687
688                         /* Check for end of chain */
689                         if (block == BLOCK_NIL)
690                                 break;
691
692                         /* Validate next block before following it... */
693                         if (block > s->lastEUN) {
694                                 printk(KERN_WARNING "INFTL: invalid previous "
695                                         "block %d in chain %d?\n", block,
696                                         first_block);
697                                 do_format_chain++;
698                                 break;
699                         }
700                 }
701
702                 if (do_format_chain) {
703                         format_chain(s, first_block);
704                         continue;
705                 }
706
707                 /*
708                  * Looks like a valid chain then. It may not really be the
709                  * newest block in the chain, but it is the newest we have
710                  * found so far. We might update it in later iterations of
711                  * this loop if we find something newer.
712                  */
713                 s->VUtable[first_logical_block] = first_block;
714                 logical_block = BLOCK_NIL;
715         }
716
717 #ifdef CONFIG_MTD_DEBUG_VERBOSE
718         if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
719                 INFTL_dumptables(s);
720 #endif
721
722         /*
723          * Second pass, check for infinite loops in chains. These are
724          * possible because we don't update the previous pointers when
725          * we fold chains. No big deal, just fix them up in PUtable.
726          */
727         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 2, validate virtual chains\n");
728         for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
729                 block = s->VUtable[logical_block];
730                 last_block = BLOCK_NIL;
731
732                 /* Check for free/reserved/nil */
733                 if (block >= BLOCK_RESERVED)
734                         continue;
735
736                 ANAC = ANACtable[block];
737                 for (i = 0; i < s->numvunits; i++) {
738                         if (s->PUtable[block] == BLOCK_NIL)
739                                 break;
740                         if (s->PUtable[block] > s->lastEUN) {
741                                 printk(KERN_WARNING "INFTL: invalid prev %d, "
742                                         "in virtual chain %d\n",
743                                         s->PUtable[block], logical_block);
744                                 s->PUtable[block] = BLOCK_NIL;
745                                         
746                         }
747                         if (ANACtable[block] != ANAC) {
748                                 /*
749                                  * Chain must point back to itself. This is ok,
750                                  * but we will need adjust the tables with this
751                                  * newest block and oldest block.
752                                  */
753                                 s->VUtable[logical_block] = block;
754                                 s->PUtable[last_block] = BLOCK_NIL;
755                                 break;
756                         }
757
758                         ANAC--;
759                         last_block = block;
760                         block = s->PUtable[block];
761                 }
762
763                 if (i >= s->nb_blocks) {
764                         /*
765                          * Uhoo, infinite chain with valid ANACS!
766                          * Format whole chain...
767                          */
768                         format_chain(s, first_block);
769                 }
770         }
771
772 #ifdef CONFIG_MTD_DEBUG_VERBOSE
773         if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
774                 INFTL_dumptables(s);
775         if (CONFIG_MTD_DEBUG_VERBOSE >= 2)
776                 INFTL_dumpVUchains(s);
777 #endif
778
779         /*
780          * Third pass, format unreferenced blocks and init free block count.
781          */
782         s->numfreeEUNs = 0;
783         s->LastFreeEUN = BLOCK_NIL;
784
785         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: pass 3, format unused blocks\n");
786         for (block = s->firstEUN; block <= s->lastEUN; block++) {
787                 if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
788                         printk("INFTL: unreferenced block %d, formatting it\n",
789                                 block);
790                         if (INFTL_formatblock(s, block) < 0)
791                                 s->PUtable[block] = BLOCK_RESERVED;
792                         else
793                                 s->PUtable[block] = BLOCK_FREE;
794                 }
795                 if (s->PUtable[block] == BLOCK_FREE) {
796                         s->numfreeEUNs++;
797                         if (s->LastFreeEUN == BLOCK_NIL)
798                                 s->LastFreeEUN = block;
799                 }
800         }
801
802         kfree(ANACtable);
803         return 0;
804 }