drivers/mtd/inftlmount.c

   1 /*
   2  * inftlmount.c -- INFTL mount code with extensive checks.
   3  *
   4  * Author: Greg Ungerer (gerg@snapgear.com)
   5  * 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 © 2000 Netgem S.A.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <asm/errno.h>
  29 #include <asm/io.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/delay.h>
  32 #include <linux/slab.h>
  33 #include <linux/mtd/mtd.h>
  34 #include <linux/mtd/nftl.h>
  35 #include <linux/mtd/inftl.h>
  36
  37 /*
  38  * find_boot_record: Find the INFTL Media Header and its Spare copy which
  39  *      contains the various device information of the INFTL partition and
  40  *      Bad Unit Table. Update the PUtable[] table according to the Bad
  41  *      Unit Table. PUtable[] is used for management of Erase Unit in
  42  *      other routines in inftlcore.c and inftlmount.c.
  43  */
  44 static int find_boot_record(struct INFTLrecord *inftl)
  45 {
  46         struct inftl_unittail h1;
  47         //struct inftl_oob oob;
  48         unsigned int i, block;
  49         u8 buf[SECTORSIZE];
  50         struct INFTLMediaHeader *mh = &inftl->MediaHdr;
  51         struct mtd_info *mtd = inftl->mbd.mtd;
  52         struct INFTLPartition *ip;
  53         size_t retlen;
  54
  55         pr_debug("INFTL: find_boot_record(inftl=%p)\n", inftl);
  56
  57         /*
  58          * Assume logical EraseSize == physical erasesize for starting the
  59          * scan. We'll sort it out later if we find a MediaHeader which says
  60          * otherwise.
  61          */
  62         inftl->EraseSize = inftl->mbd.mtd->erasesize;
  63         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
  64
  65         inftl->MediaUnit = BLOCK_NIL;
  66
  67         /* Search for a valid boot record */
  68         for (block = 0; block < inftl->nb_blocks; block++) {
  69                 int ret;
  70
  71                 /*
  72                  * Check for BNAND header first. Then whinge if it's found
  73                  * but later checks fail.
  74                  */
  75                 ret = mtd_read(mtd, block * inftl->EraseSize, SECTORSIZE,
  76                                &retlen, buf);
  77                 /* We ignore ret in case the ECC of the MediaHeader is invalid
  78                    (which is apparently acceptable) */
  79                 if (retlen != SECTORSIZE) {
  80                         static int warncount = 5;
  81
  82                         if (warncount) {
  83                                 printk(KERN_WARNING "INFTL: block read at 0x%x "
  84                                         "of mtd%d failed: %d\n",
  85                                         block * inftl->EraseSize,
  86                                         inftl->mbd.mtd->index, ret);
  87                                 if (!--warncount)
  88                                         printk(KERN_WARNING "INFTL: further "
  89                                                 "failures for this block will "
  90                                                 "not be printed\n");
  91                         }
  92                         continue;
  93                 }
  94
  95                 if (retlen < 6 || memcmp(buf, "BNAND", 6)) {
  96                         /* BNAND\0 not found. Continue */
  97                         continue;
  98                 }
  99
 100                 /* To be safer with BIOS, also use erase mark as discriminant */
 101                 ret = inftl_read_oob(mtd,
 102                                      block * inftl->EraseSize + SECTORSIZE + 8,
 103                                      8, &retlen,(char *)&h1);
 104                 if (ret < 0) {
 105                         printk(KERN_WARNING "INFTL: ANAND header found at "
 106                                 "0x%x in mtd%d, but OOB data read failed "
 107                                 "(err %d)\n", block * inftl->EraseSize,
 108                                 inftl->mbd.mtd->index, ret);
 109                         continue;
 110                 }
 111
 112
 113                 /*
 114                  * This is the first we've seen.
 115                  * Copy the media header structure into place.
 116                  */
 117                 memcpy(mh, buf, sizeof(struct INFTLMediaHeader));
 118
 119                 /* Read the spare media header at offset 4096 */
 120                 mtd_read(mtd, block * inftl->EraseSize + 4096, SECTORSIZE,
 121                          &retlen, buf);
 122                 if (retlen != SECTORSIZE) {
 123                         printk(KERN_WARNING "INFTL: Unable to read spare "
 124                                "Media Header\n");
 125                         return -1;
 126                 }
 127                 /* Check if this one is the same as the first one we found. */
 128                 if (memcmp(mh, buf, sizeof(struct INFTLMediaHeader))) {
 129                         printk(KERN_WARNING "INFTL: Primary and spare Media "
 130                                "Headers disagree.\n");
 131                         return -1;
 132                 }
 133
 134                 mh->NoOfBootImageBlocks = le32_to_cpu(mh->NoOfBootImageBlocks);
 135                 mh->NoOfBinaryPartitions = le32_to_cpu(mh->NoOfBinaryPartitions);
 136                 mh->NoOfBDTLPartitions = le32_to_cpu(mh->NoOfBDTLPartitions);
 137                 mh->BlockMultiplierBits = le32_to_cpu(mh->BlockMultiplierBits);
 138                 mh->FormatFlags = le32_to_cpu(mh->FormatFlags);
 139                 mh->PercentUsed = le32_to_cpu(mh->PercentUsed);
 140
 141                 pr_debug("INFTL: Media Header ->\n"
 142                          "    bootRecordID          = %s\n"
 143                          "    NoOfBootImageBlocks   = %d\n"
 144                          "    NoOfBinaryPartitions  = %d\n"
 145                          "    NoOfBDTLPartitions    = %d\n"
 146                          "    BlockMultiplerBits    = %d\n"
 147                          "    FormatFlgs            = %d\n"
 148                          "    OsakVersion           = 0x%x\n"
 149                          "    PercentUsed           = %d\n",
 150                          mh->bootRecordID, mh->NoOfBootImageBlocks,
 151                          mh->NoOfBinaryPartitions,
 152                          mh->NoOfBDTLPartitions,
 153                          mh->BlockMultiplierBits, mh->FormatFlags,
 154                          mh->OsakVersion, mh->PercentUsed);
 155
 156                 if (mh->NoOfBDTLPartitions == 0) {
 157                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 158                                 "failed: NoOfBDTLPartitions (%d) == 0, "
 159                                 "must be at least 1\n", mh->NoOfBDTLPartitions);
 160                         return -1;
 161                 }
 162
 163                 if ((mh->NoOfBDTLPartitions + mh->NoOfBinaryPartitions) > 4) {
 164                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 165                                 "failed: Total Partitions (%d) > 4, "
 166                                 "BDTL=%d Binary=%d\n", mh->NoOfBDTLPartitions +
 167                                 mh->NoOfBinaryPartitions,
 168                                 mh->NoOfBDTLPartitions,
 169                                 mh->NoOfBinaryPartitions);
 170                         return -1;
 171                 }
 172
 173                 if (mh->BlockMultiplierBits > 1) {
 174                         printk(KERN_WARNING "INFTL: sorry, we don't support "
 175                                 "UnitSizeFactor 0x%02x\n",
 176                                 mh->BlockMultiplierBits);
 177                         return -1;
 178                 } else if (mh->BlockMultiplierBits == 1) {
 179                         printk(KERN_WARNING "INFTL: support for INFTL with "
 180                                 "UnitSizeFactor 0x%02x is experimental\n",
 181                                 mh->BlockMultiplierBits);
 182                         inftl->EraseSize = inftl->mbd.mtd->erasesize <<
 183                                 mh->BlockMultiplierBits;
 184                         inftl->nb_blocks = (u32)inftl->mbd.mtd->size / inftl->EraseSize;
 185                         block >>= mh->BlockMultiplierBits;
 186                 }
 187
 188                 /* Scan the partitions */
 189                 for (i = 0; (i < 4); i++) {
 190                         ip = &mh->Partitions[i];
 191                         ip->virtualUnits = le32_to_cpu(ip->virtualUnits);
 192                         ip->firstUnit = le32_to_cpu(ip->firstUnit);
 193                         ip->lastUnit = le32_to_cpu(ip->lastUnit);
 194                         ip->flags = le32_to_cpu(ip->flags);
 195                         ip->spareUnits = le32_to_cpu(ip->spareUnits);
 196                         ip->Reserved0 = le32_to_cpu(ip->Reserved0);
 197
 198                         pr_debug("    PARTITION[%d] ->\n"
 199                                  "        virtualUnits    = %d\n"
 200                                  "        firstUnit       = %d\n"
 201                                  "        lastUnit        = %d\n"
 202                                  "        flags           = 0x%x\n"
 203                                  "        spareUnits      = %d\n",
 204                                  i, ip->virtualUnits, ip->firstUnit,
 205                                  ip->lastUnit, ip->flags,
 206                                  ip->spareUnits);
 207
 208                         if (ip->Reserved0 != ip->firstUnit) {
 209                                 struct erase_info *instr = &inftl->instr;
 210
 211                                 /*
 212                                  *      Most likely this is using the
 213                                  *      undocumented qiuck mount feature.
 214                                  *      We don't support that, we will need
 215                                  *      to erase the hidden block for full
 216                                  *      compatibility.
 217                                  */
 218                                 instr->addr = ip->Reserved0 * inftl->EraseSize;
 219                                 instr->len = inftl->EraseSize;
 220                                 mtd_erase(mtd, instr);
 221                         }
 222                         if ((ip->lastUnit - ip->firstUnit + 1) < ip->virtualUnits) {
 223                                 printk(KERN_WARNING "INFTL: Media Header "
 224                                         "Partition %d sanity check failed\n"
 225                                         "    firstUnit %d : lastUnit %d  >  "
 226                                         "virtualUnits %d\n", i, ip->lastUnit,
 227                                         ip->firstUnit, ip->Reserved0);
 228                                 return -1;
 229                         }
 230                         if (ip->Reserved1 != 0) {
 231                                 printk(KERN_WARNING "INFTL: Media Header "
 232                                         "Partition %d sanity check failed: "
 233                                         "Reserved1 %d != 0\n",
 234                                         i, ip->Reserved1);
 235                                 return -1;
 236                         }
 237
 238                         if (ip->flags & INFTL_BDTL)
 239                                 break;
 240                 }
 241
 242                 if (i >= 4) {
 243                         printk(KERN_WARNING "INFTL: Media Header Partition "
 244                                 "sanity check failed:\n       No partition "
 245                                 "marked as Disk Partition\n");
 246                         return -1;
 247                 }
 248
 249                 inftl->nb_boot_blocks = ip->firstUnit;
 250                 inftl->numvunits = ip->virtualUnits;
 251                 if (inftl->numvunits > (inftl->nb_blocks -
 252                     inftl->nb_boot_blocks - 2)) {
 253                         printk(KERN_WARNING "INFTL: Media Header sanity check "
 254                                 "failed:\n        numvunits (%d) > nb_blocks "
 255                                 "(%d) - nb_boot_blocks(%d) - 2\n",
 256                                 inftl->numvunits, inftl->nb_blocks,
 257                                 inftl->nb_boot_blocks);
 258                         return -1;
 259                 }
 260
 261                 inftl->mbd.size  = inftl->numvunits *
 262                         (inftl->EraseSize / SECTORSIZE);
 263
 264                 /*
 265                  * Block count is set to last used EUN (we won't need to keep
 266                  * any meta-data past that point).
 267                  */
 268                 inftl->firstEUN = ip->firstUnit;
 269                 inftl->lastEUN = ip->lastUnit;
 270                 inftl->nb_blocks = ip->lastUnit + 1;
 271
 272                 /* Memory alloc */
 273                 inftl->PUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
 274                 if (!inftl->PUtable) {
 275                         printk(KERN_WARNING "INFTL: allocation of PUtable "
 276                                 "failed (%zd bytes)\n",
 277                                 inftl->nb_blocks * sizeof(u16));
 278                         return -ENOMEM;
 279                 }
 280
 281                 inftl->VUtable = kmalloc(inftl->nb_blocks * sizeof(u16), GFP_KERNEL);
 282                 if (!inftl->VUtable) {
 283                         kfree(inftl->PUtable);
 284                         printk(KERN_WARNING "INFTL: allocation of VUtable "
 285                                 "failed (%zd bytes)\n",
 286                                 inftl->nb_blocks * sizeof(u16));
 287                         return -ENOMEM;
 288                 }
 289
 290                 /* Mark the blocks before INFTL MediaHeader as reserved */
 291                 for (i = 0; i < inftl->nb_boot_blocks; i++)
 292                         inftl->PUtable[i] = BLOCK_RESERVED;
 293                 /* Mark all remaining blocks as potentially containing data */
 294                 for (; i < inftl->nb_blocks; i++)
 295                         inftl->PUtable[i] = BLOCK_NOTEXPLORED;
 296
 297                 /* Mark this boot record (NFTL MediaHeader) block as reserved */
 298                 inftl->PUtable[block] = BLOCK_RESERVED;
 299
 300                 /* Read Bad Erase Unit Table and modify PUtable[] accordingly */
 301                 for (i = 0; i < inftl->nb_blocks; i++) {
 302                         int physblock;
 303                         /* If any of the physical eraseblocks are bad, don't
 304                            use the unit. */
 305                         for (physblock = 0; physblock < inftl->EraseSize; physblock += inftl->mbd.mtd->erasesize) {
 306                                 if (mtd_block_isbad(inftl->mbd.mtd,
 307                                                     i * inftl->EraseSize + physblock))
 308                                         inftl->PUtable[i] = BLOCK_RESERVED;
 309                         }
 310                 }
 311
 312                 inftl->MediaUnit = block;
 313                 return 0;
 314         }
 315
 316         /* Not found. */
 317         return -1;
 318 }
 319
 320 static int memcmpb(void *a, int c, int n)
 321 {
 322         int i;
 323         for (i = 0; i < n; i++) {
 324                 if (c != ((unsigned char *)a)[i])
 325                         return 1;
 326         }
 327         return 0;
 328 }
 329
 330 /*
 331  * check_free_sector: check if a free sector is actually FREE,
 332  *      i.e. All 0xff in data and oob area.
 333  */
 334 static int check_free_sectors(struct INFTLrecord *inftl, unsigned int address,
 335         int len, int check_oob)
 336 {
 337         struct mtd_info *mtd = inftl->mbd.mtd;
 338         size_t retlen;
 339         int i, ret;
 340         u8 *buf;
 341
 342         buf = kmalloc(SECTORSIZE + mtd->oobsize, GFP_KERNEL);
 343         if (!buf)
 344                 return -1;
 345
 346         ret = -1;
 347         for (i = 0; i < len; i += SECTORSIZE) {
 348                 if (mtd_read(mtd, address, SECTORSIZE, &retlen, buf))
 349                         goto out;
 350                 if (memcmpb(buf, 0xff, SECTORSIZE) != 0)
 351                         goto out;
 352
 353                 if (check_oob) {
 354                         if(inftl_read_oob(mtd, address, mtd->oobsize,
 355                                           &retlen, &buf[SECTORSIZE]) < 0)
 356                                 goto out;
 357                         if (memcmpb(buf + SECTORSIZE, 0xff, mtd->oobsize) != 0)
 358                                 goto out;
 359                 }
 360                 address += SECTORSIZE;
 361         }
 362
 363         ret = 0;
 364
 365 out:
 366         kfree(buf);
 367         return ret;
 368 }
 369
 370 /*
 371  * INFTL_format: format a Erase Unit by erasing ALL Erase Zones in the Erase
 372  *               Unit and Update INFTL metadata. Each erase operation is
 373  *               checked with check_free_sectors.
 374  *
 375  * Return: 0 when succeed, -1 on error.
 376  *
 377  * ToDo: 1. Is it necessary to check_free_sector after erasing ??
 378  */
 379 int INFTL_formatblock(struct INFTLrecord *inftl, int block)
 380 {
 381         size_t retlen;
 382         struct inftl_unittail uci;
 383         struct erase_info *instr = &inftl->instr;
 384         struct mtd_info *mtd = inftl->mbd.mtd;
 385         int physblock;
 386
 387         pr_debug("INFTL: INFTL_formatblock(inftl=%p,block=%d)\n", inftl, block);
 388
 389         memset(instr, 0, sizeof(struct erase_info));
 390
 391         /* FIXME: Shouldn't we be setting the 'discarded' flag to zero
 392            _first_? */
 393
 394         /* Use async erase interface, test return code */
 395         instr->addr = block * inftl->EraseSize;
 396         instr->len = inftl->mbd.mtd->erasesize;
 397         /* Erase one physical eraseblock at a time, even though the NAND api
 398            allows us to group them.  This way we if we have a failure, we can
 399            mark only the failed block in the bbt. */
 400         for (physblock = 0; physblock < inftl->EraseSize;
 401              physblock += instr->len, instr->addr += instr->len) {
 402                 int ret;
 403
 404                 ret = mtd_erase(inftl->mbd.mtd, instr);
 405                 if (ret) {
 406                         printk(KERN_WARNING "INFTL: error while formatting block %d\n",
 407                                 block);
 408                         goto fail;
 409                 }
 410
 411                 /*
 412                  * Check the "freeness" of Erase Unit before updating metadata.
 413                  * FixMe: is this check really necessary? Since we have check
 414                  * the return code after the erase operation.
 415                  */
 416                 if (check_free_sectors(inftl, instr->addr, instr->len, 1) != 0)
 417                         goto fail;
 418         }
 419
 420         uci.EraseMark = cpu_to_le16(ERASE_MARK);
 421         uci.EraseMark1 = cpu_to_le16(ERASE_MARK);
 422         uci.Reserved[0] = 0;
 423         uci.Reserved[1] = 0;
 424         uci.Reserved[2] = 0;
 425         uci.Reserved[3] = 0;
 426         instr->addr = block * inftl->EraseSize + SECTORSIZE * 2;
 427         if (inftl_write_oob(mtd, instr->addr + 8, 8, &retlen, (char *)&uci) < 0)
 428                 goto fail;
 429         return 0;
 430 fail:
 431         /* could not format, update the bad block table (caller is responsible
 432            for setting the PUtable to BLOCK_RESERVED on failure) */
 433         mtd_block_markbad(inftl->mbd.mtd, instr->addr);
 434         return -1;
 435 }
 436
 437 /*
 438  * format_chain: Format an invalid Virtual Unit chain. It frees all the Erase
 439  *      Units in a Virtual Unit Chain, i.e. all the units are disconnected.
 440  *
 441  *      Since the chain is invalid then we will have to erase it from its
 442  *      head (normally for INFTL we go from the oldest). But if it has a
 443  *      loop then there is no oldest...
 444  */
 445 static void format_chain(struct INFTLrecord *inftl, unsigned int first_block)
 446 {
 447         unsigned int block = first_block, block1;
 448
 449         printk(KERN_WARNING "INFTL: formatting chain at block %d\n",
 450                 first_block);
 451
 452         for (;;) {
 453                 block1 = inftl->PUtable[block];
 454
 455                 printk(KERN_WARNING "INFTL: formatting block %d\n", block);
 456                 if (INFTL_formatblock(inftl, block) < 0) {
 457                         /*
 458                          * Cannot format !!!! Mark it as Bad Unit,
 459                          */
 460                         inftl->PUtable[block] = BLOCK_RESERVED;
 461                 } else {
 462                         inftl->PUtable[block] = BLOCK_FREE;
 463                 }
 464
 465                 /* Goto next block on the chain */
 466                 block = block1;
 467
 468                 if (block == BLOCK_NIL || block >= inftl->lastEUN)
 469                         break;
 470         }
 471 }
 472
 473 void INFTL_dumptables(struct INFTLrecord *s)
 474 {
 475         int i;
 476
 477         pr_debug("-------------------------------------------"
 478                 "----------------------------------\n");
 479
 480         pr_debug("VUtable[%d] ->", s->nb_blocks);
 481         for (i = 0; i < s->nb_blocks; i++) {
 482                 if ((i % 8) == 0)
 483                         pr_debug("\n%04x: ", i);
 484                 pr_debug("%04x ", s->VUtable[i]);
 485         }
 486
 487         pr_debug("\n-------------------------------------------"
 488                 "----------------------------------\n");
 489
 490         pr_debug("PUtable[%d-%d=%d] ->", s->firstEUN, s->lastEUN, s->nb_blocks);
 491         for (i = 0; i <= s->lastEUN; i++) {
 492                 if ((i % 8) == 0)
 493                         pr_debug("\n%04x: ", i);
 494                 pr_debug("%04x ", s->PUtable[i]);
 495         }
 496
 497         pr_debug("\n-------------------------------------------"
 498                 "----------------------------------\n");
 499
 500         pr_debug("INFTL ->\n"
 501                 "  EraseSize       = %d\n"
 502                 "  h/s/c           = %d/%d/%d\n"
 503                 "  numvunits       = %d\n"
 504                 "  firstEUN        = %d\n"
 505                 "  lastEUN         = %d\n"
 506                 "  numfreeEUNs     = %d\n"
 507                 "  LastFreeEUN     = %d\n"
 508                 "  nb_blocks       = %d\n"
 509                 "  nb_boot_blocks  = %d",
 510                 s->EraseSize, s->heads, s->sectors, s->cylinders,
 511                 s->numvunits, s->firstEUN, s->lastEUN, s->numfreeEUNs,
 512                 s->LastFreeEUN, s->nb_blocks, s->nb_boot_blocks);
 513
 514         pr_debug("\n-------------------------------------------"
 515                 "----------------------------------\n");
 516 }
 517
 518 void INFTL_dumpVUchains(struct INFTLrecord *s)
 519 {
 520         int logical, block, i;
 521
 522         pr_debug("-------------------------------------------"
 523                 "----------------------------------\n");
 524
 525         pr_debug("INFTL Virtual Unit Chains:\n");
 526         for (logical = 0; logical < s->nb_blocks; logical++) {
 527                 block = s->VUtable[logical];
 528                 if (block >= s->nb_blocks)
 529                         continue;
 530                 pr_debug("  LOGICAL %d --> %d ", logical, block);
 531                 for (i = 0; i < s->nb_blocks; i++) {
 532                         if (s->PUtable[block] == BLOCK_NIL)
 533                                 break;
 534                         block = s->PUtable[block];
 535                         pr_debug("%d ", block);
 536                 }
 537                 pr_debug("\n");
 538         }
 539
 540         pr_debug("-------------------------------------------"
 541                 "----------------------------------\n");
 542 }
 543
 544 int INFTL_mount(struct INFTLrecord *s)
 545 {
 546         struct mtd_info *mtd = s->mbd.mtd;
 547         unsigned int block, first_block, prev_block, last_block;
 548         unsigned int first_logical_block, logical_block, erase_mark;
 549         int chain_length, do_format_chain;
 550         struct inftl_unithead1 h0;
 551         struct inftl_unittail h1;
 552         size_t retlen;
 553         int i;
 554         u8 *ANACtable, ANAC;
 555
 556         pr_debug("INFTL: INFTL_mount(inftl=%p)\n", s);
 557
 558         /* Search for INFTL MediaHeader and Spare INFTL Media Header */
 559         if (find_boot_record(s) < 0) {
 560                 printk(KERN_WARNING "INFTL: could not find valid boot record?\n");
 561                 return -ENXIO;
 562         }
 563
 564         /* Init the logical to physical table */
 565         for (i = 0; i < s->nb_blocks; i++)
 566                 s->VUtable[i] = BLOCK_NIL;
 567
 568         logical_block = block = BLOCK_NIL;
 569
 570         /* Temporary buffer to store ANAC numbers. */
 571         ANACtable = kcalloc(s->nb_blocks, sizeof(u8), GFP_KERNEL);
 572         if (!ANACtable) {
 573                 printk(KERN_WARNING "INFTL: allocation of ANACtable "
 574                                 "failed (%zd bytes)\n",
 575                                 s->nb_blocks * sizeof(u8));
 576                 return -ENOMEM;
 577         }
 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         pr_debug("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 (inftl_read_oob(mtd, block * s->EraseSize + 8,
 605                                            8, &retlen, (char *)&h0) < 0 ||
 606                             inftl_read_oob(mtd, block * s->EraseSize +
 607                                            2 * SECTORSIZE + 8, 8, &retlen,
 608                                            (char *)&h1) < 0) {
 609                                 /* Should never happen? */
 610                                 do_format_chain++;
 611                                 break;
 612                         }
 613
 614                         logical_block = le16_to_cpu(h0.virtualUnitNo);
 615                         prev_block = le16_to_cpu(h0.prevUnitNo);
 616                         erase_mark = le16_to_cpu((h1.EraseMark | h1.EraseMark1));
 617                         ANACtable[block] = h0.ANAC;
 618
 619                         /* Previous block is relative to start of Partition */
 620                         if (prev_block < s->nb_blocks)
 621                                 prev_block += s->firstEUN;
 622
 623                         /* Already explored partial chain? */
 624                         if (s->PUtable[block] != BLOCK_NOTEXPLORED) {
 625                                 /* Check if chain for this logical */
 626                                 if (logical_block == first_logical_block) {
 627                                         if (last_block != BLOCK_NIL)
 628                                                 s->PUtable[last_block] = block;
 629                                 }
 630                                 break;
 631                         }
 632
 633                         /* Check for invalid block */
 634                         if (erase_mark != ERASE_MARK) {
 635                                 printk(KERN_WARNING "INFTL: corrupt block %d "
 636                                         "in chain %d, chain length %d, erase "
 637                                         "mark 0x%x?\n", block, first_block,
 638                                         chain_length, erase_mark);
 639                                 /*
 640                                  * Assume end of chain, probably incomplete
 641                                  * fold/erase...
 642                                  */
 643                                 if (chain_length == 0)
 644                                         do_format_chain++;
 645                                 break;
 646                         }
 647
 648                         /* Check for it being free already then... */
 649                         if ((logical_block == BLOCK_FREE) ||
 650                             (logical_block == BLOCK_NIL)) {
 651                                 s->PUtable[block] = BLOCK_FREE;
 652                                 break;
 653                         }
 654
 655                         /* Sanity checks on block numbers */
 656                         if ((logical_block >= s->nb_blocks) ||
 657                             ((prev_block >= s->nb_blocks) &&
 658                              (prev_block != BLOCK_NIL))) {
 659                                 if (chain_length > 0) {
 660                                         printk(KERN_WARNING "INFTL: corrupt "
 661                                                 "block %d in chain %d?\n",
 662                                                 block, first_block);
 663                                         do_format_chain++;
 664                                 }
 665                                 break;
 666                         }
 667
 668                         if (first_logical_block == BLOCK_NIL) {
 669                                 first_logical_block = logical_block;
 670                         } else {
 671                                 if (first_logical_block != logical_block) {
 672                                         /* Normal for folded chain... */
 673                                         break;
 674                                 }
 675                         }
 676
 677                         /*
 678                          * Current block is valid, so if we followed a virtual
 679                          * chain to get here then we can set the previous
 680                          * block pointer in our PUtable now. Then move onto
 681                          * the previous block in the chain.
 682                          */
 683                         s->PUtable[block] = BLOCK_NIL;
 684                         if (last_block != BLOCK_NIL)
 685                                 s->PUtable[last_block] = block;
 686                         last_block = block;
 687                         block = prev_block;
 688
 689                         /* Check for end of chain */
 690                         if (block == BLOCK_NIL)
 691                                 break;
 692
 693                         /* Validate next block before following it... */
 694                         if (block > s->lastEUN) {
 695                                 printk(KERN_WARNING "INFTL: invalid previous "
 696                                         "block %d in chain %d?\n", block,
 697                                         first_block);
 698                                 do_format_chain++;
 699                                 break;
 700                         }
 701                 }
 702
 703                 if (do_format_chain) {
 704                         format_chain(s, first_block);
 705                         continue;
 706                 }
 707
 708                 /*
 709                  * Looks like a valid chain then. It may not really be the
 710                  * newest block in the chain, but it is the newest we have
 711                  * found so far. We might update it in later iterations of
 712                  * this loop if we find something newer.
 713                  */
 714                 s->VUtable[first_logical_block] = first_block;
 715                 logical_block = BLOCK_NIL;
 716         }
 717
 718         INFTL_dumptables(s);
 719
 720         /*
 721          * Second pass, check for infinite loops in chains. These are
 722          * possible because we don't update the previous pointers when
 723          * we fold chains. No big deal, just fix them up in PUtable.
 724          */
 725         pr_debug("INFTL: pass 2, validate virtual chains\n");
 726         for (logical_block = 0; logical_block < s->numvunits; logical_block++) {
 727                 block = s->VUtable[logical_block];
 728                 last_block = BLOCK_NIL;
 729
 730                 /* Check for free/reserved/nil */
 731                 if (block >= BLOCK_RESERVED)
 732                         continue;
 733
 734                 ANAC = ANACtable[block];
 735                 for (i = 0; i < s->numvunits; i++) {
 736                         if (s->PUtable[block] == BLOCK_NIL)
 737                                 break;
 738                         if (s->PUtable[block] > s->lastEUN) {
 739                                 printk(KERN_WARNING "INFTL: invalid prev %d, "
 740                                         "in virtual chain %d\n",
 741                                         s->PUtable[block], logical_block);
 742                                 s->PUtable[block] = BLOCK_NIL;
 743
 744                         }
 745                         if (ANACtable[block] != ANAC) {
 746                                 /*
 747                                  * Chain must point back to itself. This is ok,
 748                                  * but we will need adjust the tables with this
 749                                  * newest block and oldest block.
 750                                  */
 751                                 s->VUtable[logical_block] = block;
 752                                 s->PUtable[last_block] = BLOCK_NIL;
 753                                 break;
 754                         }
 755
 756                         ANAC--;
 757                         last_block = block;
 758                         block = s->PUtable[block];
 759                 }
 760
 761                 if (i >= s->nb_blocks) {
 762                         /*
 763                          * Uhoo, infinite chain with valid ANACS!
 764                          * Format whole chain...
 765                          */
 766                         format_chain(s, first_block);
 767                 }
 768         }
 769
 770         INFTL_dumptables(s);
 771         INFTL_dumpVUchains(s);
 772
 773         /*
 774          * Third pass, format unreferenced blocks and init free block count.
 775          */
 776         s->numfreeEUNs = 0;
 777         s->LastFreeEUN = BLOCK_NIL;
 778
 779         pr_debug("INFTL: pass 3, format unused blocks\n");
 780         for (block = s->firstEUN; block <= s->lastEUN; block++) {
 781                 if (s->PUtable[block] == BLOCK_NOTEXPLORED) {
 782                         printk("INFTL: unreferenced block %d, formatting it\n",
 783                                 block);
 784                         if (INFTL_formatblock(s, block) < 0)
 785                                 s->PUtable[block] = BLOCK_RESERVED;
 786                         else
 787                                 s->PUtable[block] = BLOCK_FREE;
 788                 }
 789                 if (s->PUtable[block] == BLOCK_FREE) {
 790                         s->numfreeEUNs++;
 791                         if (s->LastFreeEUN == BLOCK_NIL)
 792                                 s->LastFreeEUN = block;
 793                 }
 794         }
 795
 796         kfree(ANACtable);
 797         return 0;
 798 }