drivers/mtd/inftlcore.c

   1 /*
   2  * inftlcore.c -- Linux driver for Inverse Flash Translation Layer (INFTL)
   3  *
   4  * (C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
   5  *
   6  * Based heavily on the nftlcore.c code which is:
   7  * (c) 1999 Machine Vision Holdings, Inc.
   8  * Author: David Woodhouse <dwmw2@infradead.org>
   9  *
  10  * $Id: inftlcore.c,v 1.18 2004/11/16 18:28:59 dwmw2 Exp $
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  */
  26
  27 #include <linux/config.h>
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/delay.h>
  31 #include <linux/slab.h>
  32 #include <linux/sched.h>
  33 #include <linux/init.h>
  34 #include <linux/kmod.h>
  35 #include <linux/hdreg.h>
  36 #include <linux/mtd/mtd.h>
  37 #include <linux/mtd/nftl.h>
  38 #include <linux/mtd/inftl.h>
  39 #include <asm/uaccess.h>
  40 #include <asm/errno.h>
  41 #include <asm/io.h>
  42
  43 /*
  44  * Maximum number of loops while examining next block, to have a
  45  * chance to detect consistency problems (they should never happen
  46  * because of the checks done in the mounting.
  47  */
  48 #define MAX_LOOPS 10000
  49
  50 extern void INFTL_dumptables(struct INFTLrecord *inftl);
  51 extern void INFTL_dumpVUchains(struct INFTLrecord *inftl);
  52
  53 static void inftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
  54 {
  55         struct INFTLrecord *inftl;
  56         unsigned long temp;
  57
  58         if (mtd->type != MTD_NANDFLASH)
  59                 return;
  60         /* OK, this is moderately ugly.  But probably safe.  Alternatives? */
  61         if (memcmp(mtd->name, "DiskOnChip", 10))
  62                 return;
  63
  64         if (!mtd->block_isbad) {
  65                 printk(KERN_ERR
  66 "INFTL no longer supports the old DiskOnChip drivers loaded via docprobe.\n"
  67 "Please use the new diskonchip driver under the NAND subsystem.\n");
  68                 return;
  69         }
  70
  71         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: add_mtd for %s\n", mtd->name);
  72
  73         inftl = kmalloc(sizeof(*inftl), GFP_KERNEL);
  74
  75         if (!inftl) {
  76                 printk(KERN_WARNING "INFTL: Out of memory for data structures\n");
  77                 return;
  78         }
  79         memset(inftl, 0, sizeof(*inftl));
  80
  81         inftl->mbd.mtd = mtd;
  82         inftl->mbd.devnum = -1;
  83         inftl->mbd.blksize = 512;
  84         inftl->mbd.tr = tr;
  85         memcpy(&inftl->oobinfo, &mtd->oobinfo, sizeof(struct nand_oobinfo));
  86         inftl->oobinfo.useecc = MTD_NANDECC_PLACEONLY;
  87
  88         if (INFTL_mount(inftl) < 0) {
  89                 printk(KERN_WARNING "INFTL: could not mount device\n");
  90                 kfree(inftl);
  91                 return;
  92         }
  93
  94         /* OK, it's a new one. Set up all the data structures. */
  95
  96         /* Calculate geometry */
  97         inftl->cylinders = 1024;
  98         inftl->heads = 16;
  99
 100         temp = inftl->cylinders * inftl->heads;
 101         inftl->sectors = inftl->mbd.size / temp;
 102         if (inftl->mbd.size % temp) {
 103                 inftl->sectors++;
 104                 temp = inftl->cylinders * inftl->sectors;
 105                 inftl->heads = inftl->mbd.size / temp;
 106
 107                 if (inftl->mbd.size % temp) {
 108                         inftl->heads++;
 109                         temp = inftl->heads * inftl->sectors;
 110                         inftl->cylinders = inftl->mbd.size / temp;
 111                 }
 112         }
 113
 114         if (inftl->mbd.size != inftl->heads * inftl->cylinders * inftl->sectors) {
 115                 /*
 116                   Oh no we don't have
 117                    mbd.size == heads * cylinders * sectors
 118                 */
 119                 printk(KERN_WARNING "INFTL: cannot calculate a geometry to "
 120                        "match size of 0x%lx.\n", inftl->mbd.size);
 121                 printk(KERN_WARNING "INFTL: using C:%d H:%d S:%d "
 122                         "(== 0x%lx sects)\n",
 123                         inftl->cylinders, inftl->heads , inftl->sectors,
 124                         (long)inftl->cylinders * (long)inftl->heads *
 125                         (long)inftl->sectors );
 126         }
 127
 128         if (add_mtd_blktrans_dev(&inftl->mbd)) {
 129                 if (inftl->PUtable)
 130                         kfree(inftl->PUtable);
 131                 if (inftl->VUtable)
 132                         kfree(inftl->VUtable);
 133                 kfree(inftl);
 134                 return;
 135         }
 136 #ifdef PSYCHO_DEBUG
 137         printk(KERN_INFO "INFTL: Found new nftl%c\n", nftl->mbd.devnum + 'a');
 138 #endif
 139         return;
 140 }
 141
 142 static void inftl_remove_dev(struct mtd_blktrans_dev *dev)
 143 {
 144         struct INFTLrecord *inftl = (void *)dev;
 145
 146         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: remove_dev (i=%d)\n", dev->devnum);
 147
 148         del_mtd_blktrans_dev(dev);
 149
 150         if (inftl->PUtable)
 151                 kfree(inftl->PUtable);
 152         if (inftl->VUtable)
 153                 kfree(inftl->VUtable);
 154         kfree(inftl);
 155 }
 156
 157 /*
 158  * Actual INFTL access routines.
 159  */
 160
 161 /*
 162  * INFTL_findfreeblock: Find a free Erase Unit on the INFTL partition.
 163  *      This function is used when the give Virtual Unit Chain.
 164  */
 165 static u16 INFTL_findfreeblock(struct INFTLrecord *inftl, int desperate)
 166 {
 167         u16 pot = inftl->LastFreeEUN;
 168         int silly = inftl->nb_blocks;
 169
 170         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findfreeblock(inftl=%p,"
 171                 "desperate=%d)\n", inftl, desperate);
 172
 173         /*
 174          * Normally, we force a fold to happen before we run out of free
 175          * blocks completely.
 176          */
 177         if (!desperate && inftl->numfreeEUNs < 2) {
 178                 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: there are too few free "
 179                         "EUNs (%d)\n", inftl->numfreeEUNs);
 180                 return 0xffff;
 181         }
 182
 183         /* Scan for a free block */
 184         do {
 185                 if (inftl->PUtable[pot] == BLOCK_FREE) {
 186                         inftl->LastFreeEUN = pot;
 187                         return pot;
 188                 }
 189
 190                 if (++pot > inftl->lastEUN)
 191                         pot = 0;
 192
 193                 if (!silly--) {
 194                         printk(KERN_WARNING "INFTL: no free blocks found!  "
 195                                 "EUN range = %d - %d\n", 0, inftl->LastFreeEUN);
 196                         return BLOCK_NIL;
 197                 }
 198         } while (pot != inftl->LastFreeEUN);
 199
 200         return BLOCK_NIL;
 201 }
 202
 203 static u16 INFTL_foldchain(struct INFTLrecord *inftl, unsigned thisVUC, unsigned pendingblock)
 204 {
 205         u16 BlockMap[MAX_SECTORS_PER_UNIT];
 206         unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
 207         unsigned int thisEUN, prevEUN, status;
 208         int block, silly;
 209         unsigned int targetEUN;
 210         struct inftl_oob oob;
 211         size_t retlen;
 212
 213         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_foldchain(inftl=%p,thisVUC=%d,"
 214                 "pending=%d)\n", inftl, thisVUC, pendingblock);
 215
 216         memset(BlockMap, 0xff, sizeof(BlockMap));
 217         memset(BlockDeleted, 0, sizeof(BlockDeleted));
 218
 219         thisEUN = targetEUN = inftl->VUtable[thisVUC];
 220
 221         if (thisEUN == BLOCK_NIL) {
 222                 printk(KERN_WARNING "INFTL: trying to fold non-existent "
 223                        "Virtual Unit Chain %d!\n", thisVUC);
 224                 return BLOCK_NIL;
 225         }
 226
 227         /*
 228          * Scan to find the Erase Unit which holds the actual data for each
 229          * 512-byte block within the Chain.
 230          */
 231         silly = MAX_LOOPS;
 232         while (thisEUN < inftl->nb_blocks) {
 233                 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block ++) {
 234                         if ((BlockMap[block] != 0xffff) || BlockDeleted[block])
 235                                 continue;
 236
 237                         if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize)
 238                              + (block * SECTORSIZE), 16 , &retlen,
 239                              (char *)&oob) < 0)
 240                                 status = SECTOR_IGNORE;
 241                         else
 242                                 status = oob.b.Status | oob.b.Status1;
 243
 244                         switch(status) {
 245                         case SECTOR_FREE:
 246                         case SECTOR_IGNORE:
 247                                 break;
 248                         case SECTOR_USED:
 249                                 BlockMap[block] = thisEUN;
 250                                 continue;
 251                         case SECTOR_DELETED:
 252                                 BlockDeleted[block] = 1;
 253                                 continue;
 254                         default:
 255                                 printk(KERN_WARNING "INFTL: unknown status "
 256                                         "for block %d in EUN %d: %x\n",
 257                                         block, thisEUN, status);
 258                                 break;
 259                         }
 260                 }
 261
 262                 if (!silly--) {
 263                         printk(KERN_WARNING "INFTL: infinite loop in Virtual "
 264                                 "Unit Chain 0x%x\n", thisVUC);
 265                         return BLOCK_NIL;
 266                 }
 267
 268                 thisEUN = inftl->PUtable[thisEUN];
 269         }
 270
 271         /*
 272          * OK. We now know the location of every block in the Virtual Unit
 273          * Chain, and the Erase Unit into which we are supposed to be copying.
 274          * Go for it.
 275          */
 276         DEBUG(MTD_DEBUG_LEVEL1, "INFTL: folding chain %d into unit %d\n",
 277                 thisVUC, targetEUN);
 278
 279         for (block = 0; block < inftl->EraseSize/SECTORSIZE ; block++) {
 280                 unsigned char movebuf[SECTORSIZE];
 281                 int ret;
 282
 283                 /*
 284                  * If it's in the target EUN already, or if it's pending write,
 285                  * do nothing.
 286                  */
 287                 if (BlockMap[block] == targetEUN || (pendingblock ==
 288                     (thisVUC * (inftl->EraseSize / SECTORSIZE) + block))) {
 289                         continue;
 290                 }
 291
 292                 /*
 293                  * Copy only in non free block (free blocks can only
 294                  * happen in case of media errors or deleted blocks).
 295                  */
 296                 if (BlockMap[block] == BLOCK_NIL)
 297                         continue;
 298
 299                 ret = MTD_READ(inftl->mbd.mtd, (inftl->EraseSize *
 300                         BlockMap[block]) + (block * SECTORSIZE), SECTORSIZE,
 301                         &retlen, movebuf);
 302                 if (ret < 0) {
 303                         ret = MTD_READ(inftl->mbd.mtd, (inftl->EraseSize *
 304                                 BlockMap[block]) + (block * SECTORSIZE),
 305                                 SECTORSIZE, &retlen, movebuf);
 306                         if (ret != -EIO)
 307                                 DEBUG(MTD_DEBUG_LEVEL1, "INFTL: error went "
 308                                         "away on retry?\n");
 309                 }
 310                 memset(&oob, 0xff, sizeof(struct inftl_oob));
 311                 oob.b.Status = oob.b.Status1 = SECTOR_USED;
 312                 MTD_WRITEECC(inftl->mbd.mtd, (inftl->EraseSize * targetEUN) +
 313                         (block * SECTORSIZE), SECTORSIZE, &retlen,
 314                         movebuf, (char *)&oob, &inftl->oobinfo);
 315         }
 316
 317         /*
 318          * Newest unit in chain now contains data from _all_ older units.
 319          * So go through and erase each unit in chain, oldest first. (This
 320          * is important, by doing oldest first if we crash/reboot then it
 321          * it is relatively simple to clean up the mess).
 322          */
 323         DEBUG(MTD_DEBUG_LEVEL1, "INFTL: want to erase virtual chain %d\n",
 324                 thisVUC);
 325
 326         for (;;) {
 327                 /* Find oldest unit in chain. */
 328                 thisEUN = inftl->VUtable[thisVUC];
 329                 prevEUN = BLOCK_NIL;
 330                 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
 331                         prevEUN = thisEUN;
 332                         thisEUN = inftl->PUtable[thisEUN];
 333                 }
 334
 335                 /* Check if we are all done */
 336                 if (thisEUN == targetEUN)
 337                         break;
 338
 339                 if (INFTL_formatblock(inftl, thisEUN) < 0) {
 340                         /*
 341                          * Could not erase : mark block as reserved.
 342                          */
 343                         inftl->PUtable[thisEUN] = BLOCK_RESERVED;
 344                 } else {
 345                         /* Correctly erased : mark it as free */
 346                         inftl->PUtable[thisEUN] = BLOCK_FREE;
 347                         inftl->PUtable[prevEUN] = BLOCK_NIL;
 348                         inftl->numfreeEUNs++;
 349                 }
 350         }
 351
 352         return targetEUN;
 353 }
 354
 355 static u16 INFTL_makefreeblock(struct INFTLrecord *inftl, unsigned pendingblock)
 356 {
 357         /*
 358          * This is the part that needs some cleverness applied.
 359          * For now, I'm doing the minimum applicable to actually
 360          * get the thing to work.
 361          * Wear-levelling and other clever stuff needs to be implemented
 362          * and we also need to do some assessment of the results when
 363          * the system loses power half-way through the routine.
 364          */
 365         u16 LongestChain = 0;
 366         u16 ChainLength = 0, thislen;
 367         u16 chain, EUN;
 368
 369         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_makefreeblock(inftl=%p,"
 370                 "pending=%d)\n", inftl, pendingblock);
 371
 372         for (chain = 0; chain < inftl->nb_blocks; chain++) {
 373                 EUN = inftl->VUtable[chain];
 374                 thislen = 0;
 375
 376                 while (EUN <= inftl->lastEUN) {
 377                         thislen++;
 378                         EUN = inftl->PUtable[EUN];
 379                         if (thislen > 0xff00) {
 380                                 printk(KERN_WARNING "INFTL: endless loop in "
 381                                         "Virtual Chain %d: Unit %x\n",
 382                                         chain, EUN);
 383                                 /*
 384                                  * Actually, don't return failure.
 385                                  * Just ignore this chain and get on with it.
 386                                  */
 387                                 thislen = 0;
 388                                 break;
 389                         }
 390                 }
 391
 392                 if (thislen > ChainLength) {
 393                         ChainLength = thislen;
 394                         LongestChain = chain;
 395                 }
 396         }
 397
 398         if (ChainLength < 2) {
 399                 printk(KERN_WARNING "INFTL: no Virtual Unit Chains available "
 400                         "for folding. Failing request\n");
 401                 return BLOCK_NIL;
 402         }
 403
 404         return INFTL_foldchain(inftl, LongestChain, pendingblock);
 405 }
 406
 407 static int nrbits(unsigned int val, int bitcount)
 408 {
 409         int i, total = 0;
 410
 411         for (i = 0; (i < bitcount); i++)
 412                 total += (((0x1 << i) & val) ? 1 : 0);
 413         return total;
 414 }
 415
 416 /*
 417  * INFTL_findwriteunit: Return the unit number into which we can write
 418  *                      for this block. Make it available if it isn't already.
 419  */
 420 static inline u16 INFTL_findwriteunit(struct INFTLrecord *inftl, unsigned block)
 421 {
 422         unsigned int thisVUC = block / (inftl->EraseSize / SECTORSIZE);
 423         unsigned int thisEUN, writeEUN, prev_block, status;
 424         unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize -1);
 425         struct inftl_oob oob;
 426         struct inftl_bci bci;
 427         unsigned char anac, nacs, parity;
 428         size_t retlen;
 429         int silly, silly2 = 3;
 430
 431         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_findwriteunit(inftl=%p,"
 432                 "block=%d)\n", inftl, block);
 433
 434         do {
 435                 /*
 436                  * Scan the media to find a unit in the VUC which has
 437                  * a free space for the block in question.
 438                  */
 439                 writeEUN = BLOCK_NIL;
 440                 thisEUN = inftl->VUtable[thisVUC];
 441                 silly = MAX_LOOPS;
 442
 443                 while (thisEUN <= inftl->lastEUN) {
 444                         MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
 445                                 blockofs, 8, &retlen, (char *)&bci);
 446
 447                         status = bci.Status | bci.Status1;
 448                         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: status of block %d in "
 449                                 "EUN %d is %x\n", block , writeEUN, status);
 450
 451                         switch(status) {
 452                         case SECTOR_FREE:
 453                                 writeEUN = thisEUN;
 454                                 break;
 455                         case SECTOR_DELETED:
 456                         case SECTOR_USED:
 457                                 /* Can't go any further */
 458                                 goto hitused;
 459                         case SECTOR_IGNORE:
 460                                 break;
 461                         default:
 462                                 /*
 463                                  * Invalid block. Don't use it any more.
 464                                  * Must implement.
 465                                  */
 466                                 break;
 467                         }
 468
 469                         if (!silly--) {
 470                                 printk(KERN_WARNING "INFTL: infinite loop in "
 471                                         "Virtual Unit Chain 0x%x\n", thisVUC);
 472                                 return 0xffff;
 473                         }
 474
 475                         /* Skip to next block in chain */
 476                         thisEUN = inftl->PUtable[thisEUN];
 477                 }
 478
 479 hitused:
 480                 if (writeEUN != BLOCK_NIL)
 481                         return writeEUN;
 482
 483
 484                 /*
 485                  * OK. We didn't find one in the existing chain, or there
 486                  * is no existing chain. Allocate a new one.
 487                  */
 488                 writeEUN = INFTL_findfreeblock(inftl, 0);
 489
 490                 if (writeEUN == BLOCK_NIL) {
 491                         /*
 492                          * That didn't work - there were no free blocks just
 493                          * waiting to be picked up. We're going to have to fold
 494                          * a chain to make room.
 495                          */
 496                         thisEUN = INFTL_makefreeblock(inftl, 0xffff);
 497
 498                         /*
 499                          * Hopefully we free something, lets try again.
 500                          * This time we are desperate...
 501                          */
 502                         DEBUG(MTD_DEBUG_LEVEL1, "INFTL: using desperate==1 "
 503                                 "to find free EUN to accommodate write to "
 504                                 "VUC %d\n", thisVUC);
 505                         writeEUN = INFTL_findfreeblock(inftl, 1);
 506                         if (writeEUN == BLOCK_NIL) {
 507                                 /*
 508                                  * Ouch. This should never happen - we should
 509                                  * always be able to make some room somehow.
 510                                  * If we get here, we've allocated more storage
 511                                  * space than actual media, or our makefreeblock
 512                                  * routine is missing something.
 513                                  */
 514                                 printk(KERN_WARNING "INFTL: cannot make free "
 515                                         "space.\n");
 516 #ifdef DEBUG
 517                                 INFTL_dumptables(inftl);
 518                                 INFTL_dumpVUchains(inftl);
 519 #endif
 520                                 return BLOCK_NIL;
 521                         }
 522                 }
 523
 524                 /*
 525                  * Insert new block into virtual chain. Firstly update the
 526                  * block headers in flash...
 527                  */
 528                 anac = 0;
 529                 nacs = 0;
 530                 thisEUN = inftl->VUtable[thisVUC];
 531                 if (thisEUN != BLOCK_NIL) {
 532                         MTD_READOOB(inftl->mbd.mtd, thisEUN * inftl->EraseSize
 533                                 + 8, 8, &retlen, (char *)&oob.u);
 534                         anac = oob.u.a.ANAC + 1;
 535                         nacs = oob.u.a.NACs + 1;
 536                 }
 537
 538                 prev_block = inftl->VUtable[thisVUC];
 539                 if (prev_block < inftl->nb_blocks)
 540                         prev_block -= inftl->firstEUN;
 541
 542                 parity = (nrbits(thisVUC, 16) & 0x1) ? 0x1 : 0;
 543                 parity |= (nrbits(prev_block, 16) & 0x1) ? 0x2 : 0;
 544                 parity |= (nrbits(anac, 8) & 0x1) ? 0x4 : 0;
 545                 parity |= (nrbits(nacs, 8) & 0x1) ? 0x8 : 0;
 546
 547                 oob.u.a.virtualUnitNo = cpu_to_le16(thisVUC);
 548                 oob.u.a.prevUnitNo = cpu_to_le16(prev_block);
 549                 oob.u.a.ANAC = anac;
 550                 oob.u.a.NACs = nacs;
 551                 oob.u.a.parityPerField = parity;
 552                 oob.u.a.discarded = 0xaa;
 553
 554                 MTD_WRITEOOB(inftl->mbd.mtd, writeEUN * inftl->EraseSize + 8, 8,
 555                         &retlen, (char *)&oob.u);
 556
 557                 /* Also back up header... */
 558                 oob.u.b.virtualUnitNo = cpu_to_le16(thisVUC);
 559                 oob.u.b.prevUnitNo = cpu_to_le16(prev_block);
 560                 oob.u.b.ANAC = anac;
 561                 oob.u.b.NACs = nacs;
 562                 oob.u.b.parityPerField = parity;
 563                 oob.u.b.discarded = 0xaa;
 564
 565                 MTD_WRITEOOB(inftl->mbd.mtd, writeEUN * inftl->EraseSize +
 566                         SECTORSIZE * 4 + 8, 8, &retlen, (char *)&oob.u);
 567
 568                 inftl->PUtable[writeEUN] = inftl->VUtable[thisVUC];
 569                 inftl->VUtable[thisVUC] = writeEUN;
 570
 571                 inftl->numfreeEUNs--;
 572                 return writeEUN;
 573
 574         } while (silly2--);
 575
 576         printk(KERN_WARNING "INFTL: error folding to make room for Virtual "
 577                 "Unit Chain 0x%x\n", thisVUC);
 578         return 0xffff;
 579 }
 580
 581 /*
 582  * Given a Virtual Unit Chain, see if it can be deleted, and if so do it.
 583  */
 584 static void INFTL_trydeletechain(struct INFTLrecord *inftl, unsigned thisVUC)
 585 {
 586         unsigned char BlockUsed[MAX_SECTORS_PER_UNIT];
 587         unsigned char BlockDeleted[MAX_SECTORS_PER_UNIT];
 588         unsigned int thisEUN, status;
 589         int block, silly;
 590         struct inftl_bci bci;
 591         size_t retlen;
 592
 593         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_trydeletechain(inftl=%p,"
 594                 "thisVUC=%d)\n", inftl, thisVUC);
 595
 596         memset(BlockUsed, 0, sizeof(BlockUsed));
 597         memset(BlockDeleted, 0, sizeof(BlockDeleted));
 598
 599         thisEUN = inftl->VUtable[thisVUC];
 600         if (thisEUN == BLOCK_NIL) {
 601                 printk(KERN_WARNING "INFTL: trying to delete non-existent "
 602                        "Virtual Unit Chain %d!\n", thisVUC);
 603                 return;
 604         }
 605
 606         /*
 607          * Scan through the Erase Units to determine whether any data is in
 608          * each of the 512-byte blocks within the Chain.
 609          */
 610         silly = MAX_LOOPS;
 611         while (thisEUN < inftl->nb_blocks) {
 612                 for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++) {
 613                         if (BlockUsed[block] || BlockDeleted[block])
 614                                 continue;
 615
 616                         if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize)
 617                             + (block * SECTORSIZE), 8 , &retlen,
 618                             (char *)&bci) < 0)
 619                                 status = SECTOR_IGNORE;
 620                         else
 621                                 status = bci.Status | bci.Status1;
 622
 623                         switch(status) {
 624                         case SECTOR_FREE:
 625                         case SECTOR_IGNORE:
 626                                 break;
 627                         case SECTOR_USED:
 628                                 BlockUsed[block] = 1;
 629                                 continue;
 630                         case SECTOR_DELETED:
 631                                 BlockDeleted[block] = 1;
 632                                 continue;
 633                         default:
 634                                 printk(KERN_WARNING "INFTL: unknown status "
 635                                         "for block %d in EUN %d: 0x%x\n",
 636                                         block, thisEUN, status);
 637                         }
 638                 }
 639
 640                 if (!silly--) {
 641                         printk(KERN_WARNING "INFTL: infinite loop in Virtual "
 642                                 "Unit Chain 0x%x\n", thisVUC);
 643                         return;
 644                 }
 645
 646                 thisEUN = inftl->PUtable[thisEUN];
 647         }
 648
 649         for (block = 0; block < inftl->EraseSize/SECTORSIZE; block++)
 650                 if (BlockUsed[block])
 651                         return;
 652
 653         /*
 654          * For each block in the chain free it and make it available
 655          * for future use. Erase from the oldest unit first.
 656          */
 657         DEBUG(MTD_DEBUG_LEVEL1, "INFTL: deleting empty VUC %d\n", thisVUC);
 658
 659         for (;;) {
 660                 u16 *prevEUN = &inftl->VUtable[thisVUC];
 661                 thisEUN = *prevEUN;
 662
 663                 /* If the chain is all gone already, we're done */
 664                 if (thisEUN == BLOCK_NIL) {
 665                         DEBUG(MTD_DEBUG_LEVEL2, "INFTL: Empty VUC %d for deletion was already absent\n", thisEUN);
 666                         return;
 667                 }
 668
 669                 /* Find oldest unit in chain. */
 670                 while (inftl->PUtable[thisEUN] != BLOCK_NIL) {
 671                         BUG_ON(thisEUN >= inftl->nb_blocks);
 672
 673                         prevEUN = &inftl->PUtable[thisEUN];
 674                         thisEUN = *prevEUN;
 675                 }
 676
 677                 DEBUG(MTD_DEBUG_LEVEL3, "Deleting EUN %d from VUC %d\n",
 678                       thisEUN, thisVUC);
 679
 680                 if (INFTL_formatblock(inftl, thisEUN) < 0) {
 681                         /*
 682                          * Could not erase : mark block as reserved.
 683                          */
 684                         inftl->PUtable[thisEUN] = BLOCK_RESERVED;
 685                 } else {
 686                         /* Correctly erased : mark it as free */
 687                         inftl->PUtable[thisEUN] = BLOCK_FREE;
 688                         inftl->numfreeEUNs++;
 689                 }
 690
 691                 /* Now sort out whatever was pointing to it... */
 692                 *prevEUN = BLOCK_NIL;
 693
 694                 /* Ideally we'd actually be responsive to new
 695                    requests while we're doing this -- if there's
 696                    free space why should others be made to wait? */
 697                 cond_resched();
 698         }
 699
 700         inftl->VUtable[thisVUC] = BLOCK_NIL;
 701 }
 702
 703 static int INFTL_deleteblock(struct INFTLrecord *inftl, unsigned block)
 704 {
 705         unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
 706         unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
 707         unsigned int status;
 708         int silly = MAX_LOOPS;
 709         size_t retlen;
 710         struct inftl_bci bci;
 711
 712         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: INFTL_deleteblock(inftl=%p,"
 713                 "block=%d)\n", inftl, block);
 714
 715         while (thisEUN < inftl->nb_blocks) {
 716                 if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
 717                     blockofs, 8, &retlen, (char *)&bci) < 0)
 718                         status = SECTOR_IGNORE;
 719                 else
 720                         status = bci.Status | bci.Status1;
 721
 722                 switch (status) {
 723                 case SECTOR_FREE:
 724                 case SECTOR_IGNORE:
 725                         break;
 726                 case SECTOR_DELETED:
 727                         thisEUN = BLOCK_NIL;
 728                         goto foundit;
 729                 case SECTOR_USED:
 730                         goto foundit;
 731                 default:
 732                         printk(KERN_WARNING "INFTL: unknown status for "
 733                                 "block %d in EUN %d: 0x%x\n",
 734                                 block, thisEUN, status);
 735                         break;
 736                 }
 737
 738                 if (!silly--) {
 739                         printk(KERN_WARNING "INFTL: infinite loop in Virtual "
 740                                 "Unit Chain 0x%x\n",
 741                                 block / (inftl->EraseSize / SECTORSIZE));
 742                         return 1;
 743                 }
 744                 thisEUN = inftl->PUtable[thisEUN];
 745         }
 746
 747 foundit:
 748         if (thisEUN != BLOCK_NIL) {
 749                 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
 750
 751                 if (MTD_READOOB(inftl->mbd.mtd, ptr, 8, &retlen, (char *)&bci) < 0)
 752                         return -EIO;
 753                 bci.Status = bci.Status1 = SECTOR_DELETED;
 754                 if (MTD_WRITEOOB(inftl->mbd.mtd, ptr, 8, &retlen, (char *)&bci) < 0)
 755                         return -EIO;
 756                 INFTL_trydeletechain(inftl, block / (inftl->EraseSize / SECTORSIZE));
 757         }
 758         return 0;
 759 }
 760
 761 static int inftl_writeblock(struct mtd_blktrans_dev *mbd, unsigned long block,
 762                             char *buffer)
 763 {
 764         struct INFTLrecord *inftl = (void *)mbd;
 765         unsigned int writeEUN;
 766         unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
 767         size_t retlen;
 768         struct inftl_oob oob;
 769         char *p, *pend;
 770
 771         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_writeblock(inftl=%p,block=%ld,"
 772                 "buffer=%p)\n", inftl, block, buffer);
 773
 774         /* Is block all zero? */
 775         pend = buffer + SECTORSIZE;
 776         for (p = buffer; p < pend && !*p; p++)
 777                 ;
 778
 779         if (p < pend) {
 780                 writeEUN = INFTL_findwriteunit(inftl, block);
 781
 782                 if (writeEUN == BLOCK_NIL) {
 783                         printk(KERN_WARNING "inftl_writeblock(): cannot find "
 784                                 "block to write to\n");
 785                         /*
 786                          * If we _still_ haven't got a block to use,
 787                          * we're screwed.
 788                          */
 789                         return 1;
 790                 }
 791
 792                 memset(&oob, 0xff, sizeof(struct inftl_oob));
 793                 oob.b.Status = oob.b.Status1 = SECTOR_USED;
 794                 MTD_WRITEECC(inftl->mbd.mtd, (writeEUN * inftl->EraseSize) +
 795                         blockofs, SECTORSIZE, &retlen, (char *)buffer,
 796                         (char *)&oob, &inftl->oobinfo);
 797                 /*
 798                  * need to write SECTOR_USED flags since they are not written
 799                  * in mtd_writeecc
 800                  */
 801         } else {
 802                 INFTL_deleteblock(inftl, block);
 803         }
 804
 805         return 0;
 806 }
 807
 808 static int inftl_readblock(struct mtd_blktrans_dev *mbd, unsigned long block,
 809                            char *buffer)
 810 {
 811         struct INFTLrecord *inftl = (void *)mbd;
 812         unsigned int thisEUN = inftl->VUtable[block / (inftl->EraseSize / SECTORSIZE)];
 813         unsigned long blockofs = (block * SECTORSIZE) & (inftl->EraseSize - 1);
 814         unsigned int status;
 815         int silly = MAX_LOOPS;
 816         struct inftl_bci bci;
 817         size_t retlen;
 818
 819         DEBUG(MTD_DEBUG_LEVEL3, "INFTL: inftl_readblock(inftl=%p,block=%ld,"
 820                 "buffer=%p)\n", inftl, block, buffer);
 821
 822         while (thisEUN < inftl->nb_blocks) {
 823                 if (MTD_READOOB(inftl->mbd.mtd, (thisEUN * inftl->EraseSize) +
 824                      blockofs, 8, &retlen, (char *)&bci) < 0)
 825                         status = SECTOR_IGNORE;
 826                 else
 827                         status = bci.Status | bci.Status1;
 828
 829                 switch (status) {
 830                 case SECTOR_DELETED:
 831                         thisEUN = BLOCK_NIL;
 832                         goto foundit;
 833                 case SECTOR_USED:
 834                         goto foundit;
 835                 case SECTOR_FREE:
 836                 case SECTOR_IGNORE:
 837                         break;
 838                 default:
 839                         printk(KERN_WARNING "INFTL: unknown status for "
 840                                 "block %ld in EUN %d: 0x%04x\n",
 841                                 block, thisEUN, status);
 842                         break;
 843                 }
 844
 845                 if (!silly--) {
 846                         printk(KERN_WARNING "INFTL: infinite loop in "
 847                                 "Virtual Unit Chain 0x%lx\n",
 848                                 block / (inftl->EraseSize / SECTORSIZE));
 849                         return 1;
 850                 }
 851
 852                 thisEUN = inftl->PUtable[thisEUN];
 853         }
 854
 855 foundit:
 856         if (thisEUN == BLOCK_NIL) {
 857                 /* The requested block is not on the media, return all 0x00 */
 858                 memset(buffer, 0, SECTORSIZE);
 859         } else {
 860                 size_t retlen;
 861                 loff_t ptr = (thisEUN * inftl->EraseSize) + blockofs;
 862                 if (MTD_READ(inftl->mbd.mtd, ptr, SECTORSIZE, &retlen,
 863                     buffer))
 864                         return -EIO;
 865         }
 866         return 0;
 867 }
 868
 869 static int inftl_getgeo(struct mtd_blktrans_dev *dev, struct hd_geometry *geo)
 870 {
 871         struct INFTLrecord *inftl = (void *)dev;
 872
 873         geo->heads = inftl->heads;
 874         geo->sectors = inftl->sectors;
 875         geo->cylinders = inftl->cylinders;
 876
 877         return 0;
 878 }
 879
 880 static struct mtd_blktrans_ops inftl_tr = {
 881         .name           = "inftl",
 882         .major          = INFTL_MAJOR,
 883         .part_bits      = INFTL_PARTN_BITS,
 884         .getgeo         = inftl_getgeo,
 885         .readsect       = inftl_readblock,
 886         .writesect      = inftl_writeblock,
 887         .add_mtd        = inftl_add_mtd,
 888         .remove_dev     = inftl_remove_dev,
 889         .owner          = THIS_MODULE,
 890 };
 891
 892 extern char inftlmountrev[];
 893
 894 static int __init init_inftl(void)
 895 {
 896         printk(KERN_INFO "INFTL: inftlcore.c $Revision: 1.18 $, "
 897                 "inftlmount.c %s\n", inftlmountrev);
 898
 899         return register_mtd_blktrans(&inftl_tr);
 900 }
 901
 902 static void __exit cleanup_inftl(void)
 903 {
 904         deregister_mtd_blktrans(&inftl_tr);
 905 }
 906
 907 module_init(init_inftl);
 908 module_exit(cleanup_inftl);
 909
 910 MODULE_LICENSE("GPL");
 911 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>, David Woodhouse <dwmw2@infradead.org>, Fabrice Bellard <fabrice.bellard@netgem.com> et al.");
 912 MODULE_DESCRIPTION("Support code for Inverse Flash Translation Layer, used on M-Systems DiskOnChip 2000, Millennium and Millennium Plus");