target/linux/generic-2.6/files/fs/yaffs2/yaffs_tagscompat.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2007 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include "yaffs_guts.h"
  15 #include "yaffs_tagscompat.h"
  16 #include "yaffs_ecc.h"
  17 #include "yaffs_getblockinfo.h"
  18
  19 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND);
  20 #ifdef NOTYET
  21 static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND);
  22 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
  23                                      const __u8 * data,
  24                                      const yaffs_Spare * spare);
  25 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
  26                                     const yaffs_Spare * spare);
  27 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND);
  28 #endif
  29
  30 static const char yaffs_countBitsTable[256] = {
  31         0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4,
  32         1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  33         1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  34         2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  35         1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  36         2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  37         2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  38         3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  39         1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,
  40         2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  41         2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  42         3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  43         2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,
  44         3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  45         3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,
  46         4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8
  47 };
  48
  49 int yaffs_CountBits(__u8 x)
  50 {
  51         int retVal;
  52         retVal = yaffs_countBitsTable[x];
  53         return retVal;
  54 }
  55
  56 /********** Tags ECC calculations  *********/
  57
  58 void yaffs_CalcECC(const __u8 * data, yaffs_Spare * spare)
  59 {
  60         yaffs_ECCCalculate(data, spare->ecc1);
  61         yaffs_ECCCalculate(&data[256], spare->ecc2);
  62 }
  63
  64 void yaffs_CalcTagsECC(yaffs_Tags * tags)
  65 {
  66         /* Calculate an ecc */
  67
  68         unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
  69         unsigned i, j;
  70         unsigned ecc = 0;
  71         unsigned bit = 0;
  72
  73         tags->ecc = 0;
  74
  75         for (i = 0; i < 8; i++) {
  76                 for (j = 1; j & 0xff; j <<= 1) {
  77                         bit++;
  78                         if (b[i] & j) {
  79                                 ecc ^= bit;
  80                         }
  81                 }
  82         }
  83
  84         tags->ecc = ecc;
  85
  86 }
  87
  88 int yaffs_CheckECCOnTags(yaffs_Tags * tags)
  89 {
  90         unsigned ecc = tags->ecc;
  91
  92         yaffs_CalcTagsECC(tags);
  93
  94         ecc ^= tags->ecc;
  95
  96         if (ecc && ecc <= 64) {
  97                 /* TODO: Handle the failure better. Retire? */
  98                 unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes;
  99
 100                 ecc--;
 101
 102                 b[ecc / 8] ^= (1 << (ecc & 7));
 103
 104                 /* Now recvalc the ecc */
 105                 yaffs_CalcTagsECC(tags);
 106
 107                 return 1;       /* recovered error */
 108         } else if (ecc) {
 109                 /* Wierd ecc failure value */
 110                 /* TODO Need to do somethiong here */
 111                 return -1;      /* unrecovered error */
 112         }
 113
 114         return 0;
 115 }
 116
 117 /********** Tags **********/
 118
 119 static void yaffs_LoadTagsIntoSpare(yaffs_Spare * sparePtr,
 120                                     yaffs_Tags * tagsPtr)
 121 {
 122         yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
 123
 124         yaffs_CalcTagsECC(tagsPtr);
 125
 126         sparePtr->tagByte0 = tu->asBytes[0];
 127         sparePtr->tagByte1 = tu->asBytes[1];
 128         sparePtr->tagByte2 = tu->asBytes[2];
 129         sparePtr->tagByte3 = tu->asBytes[3];
 130         sparePtr->tagByte4 = tu->asBytes[4];
 131         sparePtr->tagByte5 = tu->asBytes[5];
 132         sparePtr->tagByte6 = tu->asBytes[6];
 133         sparePtr->tagByte7 = tu->asBytes[7];
 134 }
 135
 136 static void yaffs_GetTagsFromSpare(yaffs_Device * dev, yaffs_Spare * sparePtr,
 137                                    yaffs_Tags * tagsPtr)
 138 {
 139         yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr;
 140         int result;
 141
 142         tu->asBytes[0] = sparePtr->tagByte0;
 143         tu->asBytes[1] = sparePtr->tagByte1;
 144         tu->asBytes[2] = sparePtr->tagByte2;
 145         tu->asBytes[3] = sparePtr->tagByte3;
 146         tu->asBytes[4] = sparePtr->tagByte4;
 147         tu->asBytes[5] = sparePtr->tagByte5;
 148         tu->asBytes[6] = sparePtr->tagByte6;
 149         tu->asBytes[7] = sparePtr->tagByte7;
 150
 151         result = yaffs_CheckECCOnTags(tagsPtr);
 152         if (result > 0) {
 153                 dev->tagsEccFixed++;
 154         } else if (result < 0) {
 155                 dev->tagsEccUnfixed++;
 156         }
 157 }
 158
 159 static void yaffs_SpareInitialise(yaffs_Spare * spare)
 160 {
 161         memset(spare, 0xFF, sizeof(yaffs_Spare));
 162 }
 163
 164 static int yaffs_WriteChunkToNAND(struct yaffs_DeviceStruct *dev,
 165                                   int chunkInNAND, const __u8 * data,
 166                                   yaffs_Spare * spare)
 167 {
 168         if (chunkInNAND < dev->startBlock * dev->nChunksPerBlock) {
 169                 T(YAFFS_TRACE_ERROR,
 170                   (TSTR("**>> yaffs chunk %d is not valid" TENDSTR),
 171                    chunkInNAND));
 172                 return YAFFS_FAIL;
 173         }
 174
 175         dev->nPageWrites++;
 176         return dev->writeChunkToNAND(dev, chunkInNAND, data, spare);
 177 }
 178
 179 static int yaffs_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,
 180                                    int chunkInNAND,
 181                                    __u8 * data,
 182                                    yaffs_Spare * spare,
 183                                    yaffs_ECCResult * eccResult,
 184                                    int doErrorCorrection)
 185 {
 186         int retVal;
 187         yaffs_Spare localSpare;
 188
 189         dev->nPageReads++;
 190
 191         if (!spare && data) {
 192                 /* If we don't have a real spare, then we use a local one. */
 193                 /* Need this for the calculation of the ecc */
 194                 spare = &localSpare;
 195         }
 196
 197         if (!dev->useNANDECC) {
 198                 retVal = dev->readChunkFromNAND(dev, chunkInNAND, data, spare);
 199                 if (data && doErrorCorrection) {
 200                         /* Do ECC correction */
 201                         /* Todo handle any errors */
 202                         int eccResult1, eccResult2;
 203                         __u8 calcEcc[3];
 204
 205                         yaffs_ECCCalculate(data, calcEcc);
 206                         eccResult1 =
 207                             yaffs_ECCCorrect(data, spare->ecc1, calcEcc);
 208                         yaffs_ECCCalculate(&data[256], calcEcc);
 209                         eccResult2 =
 210                             yaffs_ECCCorrect(&data[256], spare->ecc2, calcEcc);
 211
 212                         if (eccResult1 > 0) {
 213                                 T(YAFFS_TRACE_ERROR,
 214                                   (TSTR
 215                                    ("**>>yaffs ecc error fix performed on chunk %d:0"
 216                                     TENDSTR), chunkInNAND));
 217                                 dev->eccFixed++;
 218                         } else if (eccResult1 < 0) {
 219                                 T(YAFFS_TRACE_ERROR,
 220                                   (TSTR
 221                                    ("**>>yaffs ecc error unfixed on chunk %d:0"
 222                                     TENDSTR), chunkInNAND));
 223                                 dev->eccUnfixed++;
 224                         }
 225
 226                         if (eccResult2 > 0) {
 227                                 T(YAFFS_TRACE_ERROR,
 228                                   (TSTR
 229                                    ("**>>yaffs ecc error fix performed on chunk %d:1"
 230                                     TENDSTR), chunkInNAND));
 231                                 dev->eccFixed++;
 232                         } else if (eccResult2 < 0) {
 233                                 T(YAFFS_TRACE_ERROR,
 234                                   (TSTR
 235                                    ("**>>yaffs ecc error unfixed on chunk %d:1"
 236                                     TENDSTR), chunkInNAND));
 237                                 dev->eccUnfixed++;
 238                         }
 239
 240                         if (eccResult1 || eccResult2) {
 241                                 /* We had a data problem on this page */
 242                                 yaffs_HandleReadDataError(dev, chunkInNAND);
 243                         }
 244
 245                         if (eccResult1 < 0 || eccResult2 < 0)
 246                                 *eccResult = YAFFS_ECC_RESULT_UNFIXED;
 247                         else if (eccResult1 > 0 || eccResult2 > 0)
 248                                 *eccResult = YAFFS_ECC_RESULT_FIXED;
 249                         else
 250                                 *eccResult = YAFFS_ECC_RESULT_NO_ERROR;
 251                 }
 252         } else {
 253                 /* Must allocate enough memory for spare+2*sizeof(int) */
 254                 /* for ecc results from device. */
 255                 struct yaffs_NANDSpare nspare;
 256                 retVal =
 257                     dev->readChunkFromNAND(dev, chunkInNAND, data,
 258                                            (yaffs_Spare *) & nspare);
 259                 memcpy(spare, &nspare, sizeof(yaffs_Spare));
 260                 if (data && doErrorCorrection) {
 261                         if (nspare.eccres1 > 0) {
 262                                 T(YAFFS_TRACE_ERROR,
 263                                   (TSTR
 264                                    ("**>>mtd ecc error fix performed on chunk %d:0"
 265                                     TENDSTR), chunkInNAND));
 266                         } else if (nspare.eccres1 < 0) {
 267                                 T(YAFFS_TRACE_ERROR,
 268                                   (TSTR
 269                                    ("**>>mtd ecc error unfixed on chunk %d:0"
 270                                     TENDSTR), chunkInNAND));
 271                         }
 272
 273                         if (nspare.eccres2 > 0) {
 274                                 T(YAFFS_TRACE_ERROR,
 275                                   (TSTR
 276                                    ("**>>mtd ecc error fix performed on chunk %d:1"
 277                                     TENDSTR), chunkInNAND));
 278                         } else if (nspare.eccres2 < 0) {
 279                                 T(YAFFS_TRACE_ERROR,
 280                                   (TSTR
 281                                    ("**>>mtd ecc error unfixed on chunk %d:1"
 282                                     TENDSTR), chunkInNAND));
 283                         }
 284
 285                         if (nspare.eccres1 || nspare.eccres2) {
 286                                 /* We had a data problem on this page */
 287                                 yaffs_HandleReadDataError(dev, chunkInNAND);
 288                         }
 289
 290                         if (nspare.eccres1 < 0 || nspare.eccres2 < 0)
 291                                 *eccResult = YAFFS_ECC_RESULT_UNFIXED;
 292                         else if (nspare.eccres1 > 0 || nspare.eccres2 > 0)
 293                                 *eccResult = YAFFS_ECC_RESULT_FIXED;
 294                         else
 295                                 *eccResult = YAFFS_ECC_RESULT_NO_ERROR;
 296
 297                 }
 298         }
 299         return retVal;
 300 }
 301
 302 #ifdef NOTYET
 303 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev,
 304                                   int chunkInNAND)
 305 {
 306
 307         static int init = 0;
 308         static __u8 cmpbuf[YAFFS_BYTES_PER_CHUNK];
 309         static __u8 data[YAFFS_BYTES_PER_CHUNK];
 310         /* Might as well always allocate the larger size for */
 311         /* dev->useNANDECC == true; */
 312         static __u8 spare[sizeof(struct yaffs_NANDSpare)];
 313
 314         dev->readChunkFromNAND(dev, chunkInNAND, data, (yaffs_Spare *) spare);
 315
 316         if (!init) {
 317                 memset(cmpbuf, 0xff, YAFFS_BYTES_PER_CHUNK);
 318                 init = 1;
 319         }
 320
 321         if (memcmp(cmpbuf, data, YAFFS_BYTES_PER_CHUNK))
 322                 return YAFFS_FAIL;
 323         if (memcmp(cmpbuf, spare, 16))
 324                 return YAFFS_FAIL;
 325
 326         return YAFFS_OK;
 327
 328 }
 329 #endif
 330
 331 /*
 332  * Functions for robustisizing
 333  */
 334
 335 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND)
 336 {
 337         int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
 338
 339         /* Mark the block for retirement */
 340         yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
 341         T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS,
 342           (TSTR("**>>Block %d marked for retirement" TENDSTR), blockInNAND));
 343
 344         /* TODO:
 345          * Just do a garbage collection on the affected block
 346          * then retire the block
 347          * NB recursion
 348          */
 349 }
 350
 351 #ifdef NOTYET
 352 static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND)
 353 {
 354 }
 355
 356 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND,
 357                                      const __u8 * data,
 358                                      const yaffs_Spare * spare)
 359 {
 360 }
 361
 362 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND,
 363                                     const yaffs_Spare * spare)
 364 {
 365 }
 366
 367 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND)
 368 {
 369         int blockInNAND = chunkInNAND / dev->nChunksPerBlock;
 370
 371         /* Mark the block for retirement */
 372         yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1;
 373         /* Delete the chunk */
 374         yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__);
 375 }
 376
 377 static int yaffs_VerifyCompare(const __u8 * d0, const __u8 * d1,
 378                                const yaffs_Spare * s0, const yaffs_Spare * s1)
 379 {
 380
 381         if (memcmp(d0, d1, YAFFS_BYTES_PER_CHUNK) != 0 ||
 382             s0->tagByte0 != s1->tagByte0 ||
 383             s0->tagByte1 != s1->tagByte1 ||
 384             s0->tagByte2 != s1->tagByte2 ||
 385             s0->tagByte3 != s1->tagByte3 ||
 386             s0->tagByte4 != s1->tagByte4 ||
 387             s0->tagByte5 != s1->tagByte5 ||
 388             s0->tagByte6 != s1->tagByte6 ||
 389             s0->tagByte7 != s1->tagByte7 ||
 390             s0->ecc1[0] != s1->ecc1[0] ||
 391             s0->ecc1[1] != s1->ecc1[1] ||
 392             s0->ecc1[2] != s1->ecc1[2] ||
 393             s0->ecc2[0] != s1->ecc2[0] ||
 394             s0->ecc2[1] != s1->ecc2[1] || s0->ecc2[2] != s1->ecc2[2]) {
 395                 return 0;
 396         }
 397
 398         return 1;
 399 }
 400 #endif                          /* NOTYET */
 401
 402 int yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(yaffs_Device * dev,
 403                                                     int chunkInNAND,
 404                                                     const __u8 * data,
 405                                                     const yaffs_ExtendedTags *
 406                                                     eTags)
 407 {
 408         yaffs_Spare spare;
 409         yaffs_Tags tags;
 410
 411         yaffs_SpareInitialise(&spare);
 412
 413         if (eTags->chunkDeleted) {
 414                 spare.pageStatus = 0;
 415         } else {
 416                 tags.objectId = eTags->objectId;
 417                 tags.chunkId = eTags->chunkId;
 418                 tags.byteCount = eTags->byteCount;
 419                 tags.serialNumber = eTags->serialNumber;
 420
 421                 if (!dev->useNANDECC && data) {
 422                         yaffs_CalcECC(data, &spare);
 423                 }
 424                 yaffs_LoadTagsIntoSpare(&spare, &tags);
 425
 426         }
 427
 428         return yaffs_WriteChunkToNAND(dev, chunkInNAND, data, &spare);
 429 }
 430
 431 int yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(yaffs_Device * dev,
 432                                                      int chunkInNAND,
 433                                                      __u8 * data,
 434                                                      yaffs_ExtendedTags * eTags)
 435 {
 436
 437         yaffs_Spare spare;
 438         yaffs_Tags tags;
 439         yaffs_ECCResult eccResult;
 440
 441         static yaffs_Spare spareFF;
 442         static int init = 0;
 443
 444         if (!init) {
 445                 memset(&spareFF, 0xFF, sizeof(spareFF));
 446                 init = 1;
 447         }
 448
 449         if (yaffs_ReadChunkFromNAND
 450             (dev, chunkInNAND, data, &spare, &eccResult, 1)) {
 451                 /* eTags may be NULL */
 452                 if (eTags) {
 453
 454                         int deleted =
 455                             (yaffs_CountBits(spare.pageStatus) < 7) ? 1 : 0;
 456
 457                         eTags->chunkDeleted = deleted;
 458                         eTags->eccResult = eccResult;
 459                         eTags->blockBad = 0;    /* We're reading it */
 460                         /* therefore it is not a bad block */
 461                         eTags->chunkUsed =
 462                             (memcmp(&spareFF, &spare, sizeof(spareFF)) !=
 463                              0) ? 1 : 0;
 464
 465                         if (eTags->chunkUsed) {
 466                                 yaffs_GetTagsFromSpare(dev, &spare, &tags);
 467
 468                                 eTags->objectId = tags.objectId;
 469                                 eTags->chunkId = tags.chunkId;
 470                                 eTags->byteCount = tags.byteCount;
 471                                 eTags->serialNumber = tags.serialNumber;
 472                         }
 473                 }
 474
 475                 return YAFFS_OK;
 476         } else {
 477                 return YAFFS_FAIL;
 478         }
 479 }
 480
 481 int yaffs_TagsCompatabilityMarkNANDBlockBad(struct yaffs_DeviceStruct *dev,
 482                                             int blockInNAND)
 483 {
 484
 485         yaffs_Spare spare;
 486
 487         memset(&spare, 0xff, sizeof(yaffs_Spare));
 488
 489         spare.blockStatus = 'Y';
 490
 491         yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock, NULL,
 492                                &spare);
 493         yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock + 1,
 494                                NULL, &spare);
 495
 496         return YAFFS_OK;
 497
 498 }
 499
 500 int yaffs_TagsCompatabilityQueryNANDBlock(struct yaffs_DeviceStruct *dev,
 501                                           int blockNo,
 502                                           yaffs_BlockState *state,
 503                                           __u32 *sequenceNumber)
 504 {
 505
 506         yaffs_Spare spare0, spare1;
 507         static yaffs_Spare spareFF;
 508         static int init;
 509         yaffs_ECCResult dummy;
 510
 511         if (!init) {
 512                 memset(&spareFF, 0xFF, sizeof(spareFF));
 513                 init = 1;
 514         }
 515
 516         *sequenceNumber = 0;
 517
 518         yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock, NULL,
 519                                 &spare0, &dummy, 1);
 520         yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock + 1, NULL,
 521                                 &spare1, &dummy, 1);
 522
 523         if (yaffs_CountBits(spare0.blockStatus & spare1.blockStatus) < 7)
 524                 *state = YAFFS_BLOCK_STATE_DEAD;
 525         else if (memcmp(&spareFF, &spare0, sizeof(spareFF)) == 0)
 526                 *state = YAFFS_BLOCK_STATE_EMPTY;
 527         else
 528                 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING;
 529
 530         return YAFFS_OK;
 531 }