1 /* 2 * YAFFS: Yet another FFS. A NAND-flash specific file system. 3 * yaffs_tagscompat.h: Tags compatability layer to use YAFFS1 formatted NAND. 4 * 5 * Copyright (C) 2002 Aleph One Ltd. 6 * 7 * Created by Charles Manning <charles (at) 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 * $Id: yaffs_tagscompat.c,v 1.8 2005/11/29 20:54:32 marty Exp $ 14 */ 15 16 #include "yaffs_guts.h" 17 #include "yaffs_tagscompat.h" 18 #include "yaffs_ecc.h" 19 20 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND); 21 #ifdef NOTYET 22 static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND); 23 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND, 24 const __u8 * data, 25 const yaffs_Spare * spare); 26 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND, 27 const yaffs_Spare * spare); 28 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND); 29 #endif 30 31 static const char yaffs_countBitsTable[256] = { 32 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 33 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 34 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 35 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 36 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 37 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 38 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 39 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 40 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 41 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 42 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 43 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 44 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 45 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 46 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 47 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 48 }; 49 50 static int yaffs_CountBits(__u8 x) 51 { 52 int retVal; 53 retVal = yaffs_countBitsTable[x]; 54 return retVal; 55 } 56 57 /********** Tags ECC calculations *********/ 58 59 void yaffs_CalcECC(const __u8 * data, yaffs_Spare * spare) 60 { 61 yaffs_ECCCalculate(data, spare->ecc1); 62 yaffs_ECCCalculate(&data[256], spare->ecc2); 63 } 64 65 void yaffs_CalcTagsECC(yaffs_Tags * tags) 66 { 67 /* Calculate an ecc */ 68 69 unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes; 70 unsigned i, j; 71 unsigned ecc = 0; 72 unsigned bit = 0; 73 74 tags->ecc = 0; 75 76 for (i = 0; i < 8; i++) { 77 for (j = 1; j & 0xff; j <<= 1) { 78 bit++; 79 if (b[i] & j) { 80 ecc ^= bit; 81 } 82 } 83 } 84 85 tags->ecc = ecc; 86 87 } 88 89 int yaffs_CheckECCOnTags(yaffs_Tags * tags) 90 { 91 unsigned ecc = tags->ecc; 92 93 yaffs_CalcTagsECC(tags); 94 95 ecc ^= tags->ecc; 96 97 if (ecc && ecc <= 64) { 98 /* TODO: Handle the failure better. Retire? */ 99 unsigned char *b = ((yaffs_TagsUnion *) tags)->asBytes; 100 101 ecc--; 102 103 b[ecc / 8] ^= (1 << (ecc & 7)); 104 105 /* Now recvalc the ecc */ 106 yaffs_CalcTagsECC(tags); 107 108 return 1; /* recovered error */ 109 } else if (ecc) { 110 /* Wierd ecc failure value */ 111 /* TODO Need to do somethiong here */ 112 return -1; /* unrecovered error */ 113 } 114 115 return 0; 116 } 117 118 /********** Tags **********/ 119 120 static void yaffs_LoadTagsIntoSpare(yaffs_Spare * sparePtr, 121 yaffs_Tags * tagsPtr) 122 { 123 yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr; 124 125 yaffs_CalcTagsECC(tagsPtr); 126 127 sparePtr->tagByte0 = tu->asBytes[0]; 128 sparePtr->tagByte1 = tu->asBytes[1]; 129 sparePtr->tagByte2 = tu->asBytes[2]; 130 sparePtr->tagByte3 = tu->asBytes[3]; 131 sparePtr->tagByte4 = tu->asBytes[4]; 132 sparePtr->tagByte5 = tu->asBytes[5]; 133 sparePtr->tagByte6 = tu->asBytes[6]; 134 sparePtr->tagByte7 = tu->asBytes[7]; 135 } 136 137 static void yaffs_GetTagsFromSpare(yaffs_Device * dev, yaffs_Spare * sparePtr, 138 yaffs_Tags * tagsPtr) 139 { 140 yaffs_TagsUnion *tu = (yaffs_TagsUnion *) tagsPtr; 141 int result; 142 143 tu->asBytes[0] = sparePtr->tagByte0; 144 tu->asBytes[1] = sparePtr->tagByte1; 145 tu->asBytes[2] = sparePtr->tagByte2; 146 tu->asBytes[3] = sparePtr->tagByte3; 147 tu->asBytes[4] = sparePtr->tagByte4; 148 tu->asBytes[5] = sparePtr->tagByte5; 149 tu->asBytes[6] = sparePtr->tagByte6; 150 tu->asBytes[7] = sparePtr->tagByte7; 151 152 result = yaffs_CheckECCOnTags(tagsPtr); 153 if (result > 0) { 154 dev->tagsEccFixed++; 155 } else if (result < 0) { 156 dev->tagsEccUnfixed++; 157 } 158 } 159 160 static void yaffs_SpareInitialise(yaffs_Spare * spare) 161 { 162 memset(spare, 0xFF, sizeof(yaffs_Spare)); 163 } 164 165 static int yaffs_WriteChunkToNAND(struct yaffs_DeviceStruct *dev, 166 int chunkInNAND, const __u8 * data, 167 yaffs_Spare * spare) 168 { 169 if (chunkInNAND < dev->startBlock * dev->nChunksPerBlock) { 170 T(YAFFS_TRACE_ERROR, 171 (TSTR("**>> yaffs chunk %d is not valid" TENDSTR), 172 chunkInNAND)); 173 return YAFFS_FAIL; 174 } 175 176 dev->nPageWrites++; 177 return dev->writeChunkToNAND(dev, chunkInNAND, data, spare); 178 } 179 180 static int yaffs_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev, 181 int chunkInNAND, 182 __u8 * data, 183 yaffs_Spare * spare, 184 yaffs_ECCResult * eccResult, 185 int doErrorCorrection) 186 { 187 int retVal; 188 yaffs_Spare localSpare; 189 190 dev->nPageReads++; 191 192 if (!spare && data) { 193 /* If we don't have a real spare, then we use a local one. */ 194 /* Need this for the calculation of the ecc */ 195 spare = &localSpare; 196 } 197 198 if (!dev->useNANDECC) { 199 retVal = dev->readChunkFromNAND(dev, chunkInNAND, data, spare); 200 if (data && doErrorCorrection) { 201 /* Do ECC correction */ 202 /* Todo handle any errors */ 203 int eccResult1, eccResult2; 204 __u8 calcEcc[3]; 205 206 yaffs_ECCCalculate(data, calcEcc); 207 eccResult1 = 208 yaffs_ECCCorrect(data, spare->ecc1, calcEcc); 209 yaffs_ECCCalculate(&data[256], calcEcc); 210 eccResult2 = 211 yaffs_ECCCorrect(&data[256], spare->ecc2, calcEcc); 212 213 if (eccResult1 > 0) { 214 T(YAFFS_TRACE_ERROR, 215 (TSTR 216 ("**>>yaffs ecc error fix performed on chunk %d:0" 217 TENDSTR), chunkInNAND)); 218 dev->eccFixed++; 219 } else if (eccResult1 < 0) { 220 T(YAFFS_TRACE_ERROR, 221 (TSTR 222 ("**>>yaffs ecc error unfixed on chunk %d:0" 223 TENDSTR), chunkInNAND)); 224 dev->eccUnfixed++; 225 } 226 227 if (eccResult2 > 0) { 228 T(YAFFS_TRACE_ERROR, 229 (TSTR 230 ("**>>yaffs ecc error fix performed on chunk %d:1" 231 TENDSTR), chunkInNAND)); 232 dev->eccFixed++; 233 } else if (eccResult2 < 0) { 234 T(YAFFS_TRACE_ERROR, 235 (TSTR 236 ("**>>yaffs ecc error unfixed on chunk %d:1" 237 TENDSTR), chunkInNAND)); 238 dev->eccUnfixed++; 239 } 240 241 if (eccResult1 || eccResult2) { 242 /* We had a data problem on this page */ 243 yaffs_HandleReadDataError(dev, chunkInNAND); 244 } 245 246 if (eccResult1 < 0 || eccResult2 < 0) 247 *eccResult = YAFFS_ECC_RESULT_UNFIXED; 248 else if (eccResult1 > 0 || eccResult2 > 0) 249 *eccResult = YAFFS_ECC_RESULT_FIXED; 250 else 251 *eccResult = YAFFS_ECC_RESULT_NO_ERROR; 252 } 253 } else { 254 /* Must allocate enough memory for spare+2*sizeof(int) */ 255 /* for ecc results from device. */ 256 struct yaffs_NANDSpare nspare; 257 retVal = 258 dev->readChunkFromNAND(dev, chunkInNAND, data, 259 (yaffs_Spare *) & nspare); 260 memcpy(spare, &nspare, sizeof(yaffs_Spare)); 261 if (data && doErrorCorrection) { 262 if (nspare.eccres1 > 0) { 263 T(YAFFS_TRACE_ERROR, 264 (TSTR 265 ("**>>mtd ecc error fix performed on chunk %d:0" 266 TENDSTR), chunkInNAND)); 267 } else if (nspare.eccres1 < 0) { 268 T(YAFFS_TRACE_ERROR, 269 (TSTR 270 ("**>>mtd ecc error unfixed on chunk %d:0" 271 TENDSTR), chunkInNAND)); 272 } 273 274 if (nspare.eccres2 > 0) { 275 T(YAFFS_TRACE_ERROR, 276 (TSTR 277 ("**>>mtd ecc error fix performed on chunk %d:1" 278 TENDSTR), chunkInNAND)); 279 } else if (nspare.eccres2 < 0) { 280 T(YAFFS_TRACE_ERROR, 281 (TSTR 282 ("**>>mtd ecc error unfixed on chunk %d:1" 283 TENDSTR), chunkInNAND)); 284 } 285 286 if (nspare.eccres1 || nspare.eccres2) { 287 /* We had a data problem on this page */ 288 yaffs_HandleReadDataError(dev, chunkInNAND); 289 } 290 291 if (nspare.eccres1 < 0 || nspare.eccres2 < 0) 292 *eccResult = YAFFS_ECC_RESULT_UNFIXED; 293 else if (nspare.eccres1 > 0 || nspare.eccres2 > 0) 294 *eccResult = YAFFS_ECC_RESULT_FIXED; 295 else 296 *eccResult = YAFFS_ECC_RESULT_NO_ERROR; 297 298 } 299 } 300 return retVal; 301 } 302 303 #ifdef NOTYET 304 static int yaffs_CheckChunkErased(struct yaffs_DeviceStruct *dev, 305 int chunkInNAND) 306 { 307 308 static int init = 0; 309 static __u8 cmpbuf[YAFFS_BYTES_PER_CHUNK]; 310 static __u8 data[YAFFS_BYTES_PER_CHUNK]; 311 /* Might as well always allocate the larger size for */ 312 /* dev->useNANDECC == true; */ 313 static __u8 spare[sizeof(struct yaffs_NANDSpare)]; 314 315 dev->readChunkFromNAND(dev, chunkInNAND, data, (yaffs_Spare *) spare); 316 317 if (!init) { 318 memset(cmpbuf, 0xff, YAFFS_BYTES_PER_CHUNK); 319 init = 1; 320 } 321 322 if (memcmp(cmpbuf, data, YAFFS_BYTES_PER_CHUNK)) 323 return YAFFS_FAIL; 324 if (memcmp(cmpbuf, spare, 16)) 325 return YAFFS_FAIL; 326 327 return YAFFS_OK; 328 329 } 330 #endif 331 332 /* 333 * Functions for robustisizing 334 */ 335 336 static void yaffs_HandleReadDataError(yaffs_Device * dev, int chunkInNAND) 337 { 338 int blockInNAND = chunkInNAND / dev->nChunksPerBlock; 339 340 /* Mark the block for retirement */ 341 yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1; 342 T(YAFFS_TRACE_ERROR | YAFFS_TRACE_BAD_BLOCKS, 343 (TSTR("**>>Block %d marked for retirement" TENDSTR), blockInNAND)); 344 345 /* TODO: 346 * Just do a garbage collection on the affected block 347 * then retire the block 348 * NB recursion 349 */ 350 } 351 352 #ifdef NOTYET 353 static void yaffs_CheckWrittenBlock(yaffs_Device * dev, int chunkInNAND) 354 { 355 } 356 357 static void yaffs_HandleWriteChunkOk(yaffs_Device * dev, int chunkInNAND, 358 const __u8 * data, 359 const yaffs_Spare * spare) 360 { 361 } 362 363 static void yaffs_HandleUpdateChunk(yaffs_Device * dev, int chunkInNAND, 364 const yaffs_Spare * spare) 365 { 366 } 367 368 static void yaffs_HandleWriteChunkError(yaffs_Device * dev, int chunkInNAND) 369 { 370 int blockInNAND = chunkInNAND / dev->nChunksPerBlock; 371 372 /* Mark the block for retirement */ 373 yaffs_GetBlockInfo(dev, blockInNAND)->needsRetiring = 1; 374 /* Delete the chunk */ 375 yaffs_DeleteChunk(dev, chunkInNAND, 1, __LINE__); 376 } 377 378 static int yaffs_VerifyCompare(const __u8 * d0, const __u8 * d1, 379 const yaffs_Spare * s0, const yaffs_Spare * s1) 380 { 381 382 if (memcmp(d0, d1, YAFFS_BYTES_PER_CHUNK) != 0 || 383 s0->tagByte0 != s1->tagByte0 || 384 s0->tagByte1 != s1->tagByte1 || 385 s0->tagByte2 != s1->tagByte2 || 386 s0->tagByte3 != s1->tagByte3 || 387 s0->tagByte4 != s1->tagByte4 || 388 s0->tagByte5 != s1->tagByte5 || 389 s0->tagByte6 != s1->tagByte6 || 390 s0->tagByte7 != s1->tagByte7 || 391 s0->ecc1[0] != s1->ecc1[0] || 392 s0->ecc1[1] != s1->ecc1[1] || 393 s0->ecc1[2] != s1->ecc1[2] || 394 s0->ecc2[0] != s1->ecc2[0] || 395 s0->ecc2[1] != s1->ecc2[1] || s0->ecc2[2] != s1->ecc2[2]) { 396 return 0; 397 } 398 399 return 1; 400 } 401 #endif /* NOTYET */ 402 403 int yaffs_TagsCompatabilityWriteChunkWithTagsToNAND(yaffs_Device * dev, 404 int chunkInNAND, 405 const __u8 * data, 406 const yaffs_ExtendedTags * 407 eTags) 408 { 409 yaffs_Spare spare; 410 yaffs_Tags tags; 411 412 yaffs_SpareInitialise(&spare); 413 414 if (eTags->chunkDeleted) { 415 spare.pageStatus = 0; 416 } else { 417 tags.objectId = eTags->objectId; 418 tags.chunkId = eTags->chunkId; 419 tags.byteCount = eTags->byteCount; 420 tags.serialNumber = eTags->serialNumber; 421 422 if (!dev->useNANDECC && data) { 423 yaffs_CalcECC(data, &spare); 424 } 425 yaffs_LoadTagsIntoSpare(&spare, &tags); 426 427 } 428 429 return yaffs_WriteChunkToNAND(dev, chunkInNAND, data, &spare); 430 } 431 432 int yaffs_TagsCompatabilityReadChunkWithTagsFromNAND(yaffs_Device * dev, 433 int chunkInNAND, 434 __u8 * data, 435 yaffs_ExtendedTags * eTags) 436 { 437 438 yaffs_Spare spare; 439 yaffs_Tags tags; 440 yaffs_ECCResult eccResult; 441 442 static yaffs_Spare spareFF; 443 static int init; 444 445 if (!init) { 446 memset(&spareFF, 0xFF, sizeof(spareFF)); 447 init = 1; 448 } 449 450 if (yaffs_ReadChunkFromNAND 451 (dev, chunkInNAND, data, &spare, &eccResult, 1)) { 452 /* eTags may be NULL */ 453 if (eTags) { 454 455 int deleted = 456 (yaffs_CountBits(spare.pageStatus) < 7) ? 1 : 0; 457 458 eTags->chunkDeleted = deleted; 459 eTags->eccResult = eccResult; 460 eTags->blockBad = 0; /* We're reading it */ 461 /* therefore it is not a bad block */ 462 eTags->chunkUsed = 463 (memcmp(&spareFF, &spare, sizeof(spareFF)) != 464 0) ? 1 : 0; 465 466 if (eTags->chunkUsed) { 467 yaffs_GetTagsFromSpare(dev, &spare, &tags); 468 469 eTags->objectId = tags.objectId; 470 eTags->chunkId = tags.chunkId; 471 eTags->byteCount = tags.byteCount; 472 eTags->serialNumber = tags.serialNumber; 473 } 474 } 475 476 return YAFFS_OK; 477 } else { 478 return YAFFS_FAIL; 479 } 480 } 481 482 int yaffs_TagsCompatabilityMarkNANDBlockBad(struct yaffs_DeviceStruct *dev, 483 int blockInNAND) 484 { 485 486 yaffs_Spare spare; 487 488 memset(&spare, 0xff, sizeof(yaffs_Spare)); 489 490 spare.blockStatus = 'Y'; 491 492 yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock, NULL, 493 &spare); 494 yaffs_WriteChunkToNAND(dev, blockInNAND * dev->nChunksPerBlock + 1, 495 NULL, &spare); 496 497 return YAFFS_OK; 498 499 } 500 501 int yaffs_TagsCompatabilityQueryNANDBlock(struct yaffs_DeviceStruct *dev, 502 int blockNo, yaffs_BlockState * 503 state, 504 int *sequenceNumber) 505 { 506 507 yaffs_Spare spare0, spare1; 508 static yaffs_Spare spareFF; 509 static int init; 510 yaffs_ECCResult dummy; 511 512 if (!init) { 513 memset(&spareFF, 0xFF, sizeof(spareFF)); 514 init = 1; 515 } 516 517 *sequenceNumber = 0; 518 519 yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock, NULL, 520 &spare0, &dummy, 1); 521 yaffs_ReadChunkFromNAND(dev, blockNo * dev->nChunksPerBlock + 1, NULL, 522 &spare1, &dummy, 1); 523 524 if (yaffs_CountBits(spare0.blockStatus & spare1.blockStatus) < 7) 525 *state = YAFFS_BLOCK_STATE_DEAD; 526 else if (memcmp(&spareFF, &spare0, sizeof(spareFF)) == 0) 527 *state = YAFFS_BLOCK_STATE_EMPTY; 528 else 529 *state = YAFFS_BLOCK_STATE_NEEDS_SCANNING; 530 531 return YAFFS_OK; 532 } 533
