1/* 2 * drivers/mtd/nand_bbt.c 3 * 4 * Overview: 5 * Bad block table support for the NAND driver 6 * 7 * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de) 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 * Description: 14 * 15 * When nand_scan_bbt is called, then it tries to find the bad block table 16 * depending on the options in the BBT descriptor(s). If no flash based BBT 17 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory 18 * marked good / bad blocks. This information is used to create a memory BBT. 19 * Once a new bad block is discovered then the "factory" information is updated 20 * on the device. 21 * If a flash based BBT is specified then the function first tries to find the 22 * BBT on flash. If a BBT is found then the contents are read and the memory 23 * based BBT is created. If a mirrored BBT is selected then the mirror is 24 * searched too and the versions are compared. If the mirror has a greater 25 * version number than the mirror BBT is used to build the memory based BBT. 26 * If the tables are not versioned, then we "or" the bad block information. 27 * If one of the BBTs is out of date or does not exist it is (re)created. 28 * If no BBT exists at all then the device is scanned for factory marked 29 * good / bad blocks and the bad block tables are created. 30 * 31 * For manufacturer created BBTs like the one found on M-SYS DOC devices 32 * the BBT is searched and read but never created 33 * 34 * The auto generated bad block table is located in the last good blocks 35 * of the device. The table is mirrored, so it can be updated eventually. 36 * The table is marked in the OOB area with an ident pattern and a version 37 * number which indicates which of both tables is more up to date. If the NAND 38 * controller needs the complete OOB area for the ECC information then the 39 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of 40 * course): it moves the ident pattern and the version byte into the data area 41 * and the OOB area will remain untouched. 42 * 43 * The table uses 2 bits per block 44 * 11b: block is good 45 * 00b: block is factory marked bad 46 * 01b, 10b: block is marked bad due to wear 47 * 48 * The memory bad block table uses the following scheme: 49 * 00b: block is good 50 * 01b: block is marked bad due to wear 51 * 10b: block is reserved (to protect the bbt area) 52 * 11b: block is factory marked bad 53 * 54 * Multichip devices like DOC store the bad block info per floor. 55 * 56 * Following assumptions are made: 57 * - bbts start at a page boundary, if autolocated on a block boundary 58 * - the space necessary for a bbt in FLASH does not exceed a block boundary 59 * 60 */ 61 62#include <linux/slab.h> 63#include <linux/types.h> 64#include <linux/mtd/mtd.h> 65#include <linux/mtd/nand.h> 66#include <linux/mtd/nand_ecc.h> 67#include <linux/bitops.h> 68#include <linux/delay.h> 69#include <linux/vmalloc.h> 70#include <linux/export.h> 71 72static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td) 73{ 74 int ret; 75 76 ret = memcmp(buf, td->pattern, td->len); 77 if (!ret) 78 return ret; 79 return -1; 80} 81 82/** 83 * check_pattern - [GENERIC] check if a pattern is in the buffer 84 * @buf: the buffer to search 85 * @len: the length of buffer to search 86 * @paglen: the pagelength 87 * @td: search pattern descriptor 88 * 89 * Check for a pattern at the given place. Used to search bad block tables and 90 * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if 91 * all bytes except the pattern area contain 0xff. 92 */ 93static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td) 94{ 95 int i, end = 0; 96 uint8_t *p = buf; 97 98 if (td->options & NAND_BBT_NO_OOB) 99 return check_pattern_no_oob(buf, td); 100 101 end = paglen + td->offs; 102 if (td->options & NAND_BBT_SCANEMPTY) { 103 for (i = 0; i < end; i++) { 104 if (p[i] != 0xff) 105 return -1; 106 } 107 } 108 p += end; 109 110 /* Compare the pattern */ 111 if (memcmp(p, td->pattern, td->len)) 112 return -1; 113 114 if (td->options & NAND_BBT_SCANEMPTY) { 115 p += td->len; 116 end += td->len; 117 for (i = end; i < len; i++) { 118 if (*p++ != 0xff) 119 return -1; 120 } 121 } 122 return 0; 123} 124 125/** 126 * check_short_pattern - [GENERIC] check if a pattern is in the buffer 127 * @buf: the buffer to search 128 * @td: search pattern descriptor 129 * 130 * Check for a pattern at the given place. Used to search bad block tables and 131 * good / bad block identifiers. Same as check_pattern, but no optional empty 132 * check. 133 */ 134static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td) 135{ 136 int i; 137 uint8_t *p = buf; 138 139 /* Compare the pattern */ 140 for (i = 0; i < td->len; i++) { 141 if (p[td->offs + i] != td->pattern[i]) 142 return -1; 143 } 144 return 0; 145} 146 147/** 148 * add_marker_len - compute the length of the marker in data area 149 * @td: BBT descriptor used for computation 150 * 151 * The length will be 0 if the marker is located in OOB area. 152 */ 153static u32 add_marker_len(struct nand_bbt_descr *td) 154{ 155 u32 len; 156 157 if (!(td->options & NAND_BBT_NO_OOB)) 158 return 0; 159 160 len = td->len; 161 if (td->options & NAND_BBT_VERSION) 162 len++; 163 return len; 164} 165 166/** 167 * read_bbt - [GENERIC] Read the bad block table starting from page 168 * @mtd: MTD device structure 169 * @buf: temporary buffer 170 * @page: the starting page 171 * @num: the number of bbt descriptors to read 172 * @td: the bbt describtion table 173 * @offs: offset in the memory table 174 * 175 * Read the bad block table starting from page. 176 */ 177static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num, 178 struct nand_bbt_descr *td, int offs) 179{ 180 int res, ret = 0, i, j, act = 0; 181 struct nand_chip *this = mtd->priv; 182 size_t retlen, len, totlen; 183 loff_t from; 184 int bits = td->options & NAND_BBT_NRBITS_MSK; 185 uint8_t msk = (uint8_t)((1 << bits) - 1); 186 u32 marker_len; 187 int reserved_block_code = td->reserved_block_code; 188 189 totlen = (num * bits) >> 3; 190 marker_len = add_marker_len(td); 191 from = ((loff_t)page) << this->page_shift; 192 193 while (totlen) { 194 len = min(totlen, (size_t)(1 << this->bbt_erase_shift)); 195 if (marker_len) { 196 /* 197 * In case the BBT marker is not in the OOB area it 198 * will be just in the first page. 199 */ 200 len -= marker_len; 201 from += marker_len; 202 marker_len = 0; 203 } 204 res = mtd_read(mtd, from, len, &retlen, buf); 205 if (res < 0) { 206 if (mtd_is_eccerr(res)) { 207 pr_info("nand_bbt: ECC error in BBT at " 208 "0x%012llx\n", from & ~mtd->writesize); 209 return res; 210 } else if (mtd_is_bitflip(res)) { 211 pr_info("nand_bbt: corrected error in BBT at " 212 "0x%012llx\n", from & ~mtd->writesize); 213 ret = res; 214 } else { 215 pr_info("nand_bbt: error reading BBT\n"); 216 return res; 217 } 218 } 219 220 /* Analyse data */ 221 for (i = 0; i < len; i++) { 222 uint8_t dat = buf[i]; 223 for (j = 0; j < 8; j += bits, act += 2) { 224 uint8_t tmp = (dat >> j) & msk; 225 if (tmp == msk) 226 continue; 227 if (reserved_block_code && (tmp == reserved_block_code)) { 228 pr_info("nand_read_bbt: reserved block at 0x%012llx\n", 229 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); 230 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06); 231 mtd->ecc_stats.bbtblocks++; 232 continue; 233 } 234 /* 235 * Leave it for now, if it's matured we can 236 * move this message to pr_debug. 237 */ 238 pr_info("nand_read_bbt: bad block at 0x%012llx\n", 239 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); 240 /* Factory marked bad or worn out? */ 241 if (tmp == 0) 242 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06); 243 else 244 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06); 245 mtd->ecc_stats.badblocks++; 246 } 247 } 248 totlen -= len; 249 from += len; 250 } 251 return ret; 252} 253 254/** 255 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page 256 * @mtd: MTD device structure 257 * @buf: temporary buffer 258 * @td: descriptor for the bad block table 259 * @chip: read the table for a specific chip, -1 read all chips; applies only if 260 * NAND_BBT_PERCHIP option is set 261 * 262 * Read the bad block table for all chips starting at a given page. We assume 263 * that the bbt bits are in consecutive order. 264 */ 265static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip) 266{ 267 struct nand_chip *this = mtd->priv; 268 int res = 0, i; 269 270 if (td->options & NAND_BBT_PERCHIP) { 271 int offs = 0; 272 for (i = 0; i < this->numchips; i++) { 273 if (chip == -1 || chip == i) 274 res = read_bbt(mtd, buf, td->pages[i], 275 this->chipsize >> this->bbt_erase_shift, 276 td, offs); 277 if (res) 278 return res; 279 offs += this->chipsize >> (this->bbt_erase_shift + 2); 280 } 281 } else { 282 res = read_bbt(mtd, buf, td->pages[0], 283 mtd->size >> this->bbt_erase_shift, td, 0); 284 if (res) 285 return res; 286 } 287 return 0; 288} 289 290/* BBT marker is in the first page, no OOB */ 291static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs, 292 struct nand_bbt_descr *td) 293{ 294 size_t retlen; 295 size_t len; 296 297 len = td->len; 298 if (td->options & NAND_BBT_VERSION) 299 len++; 300 301 return mtd_read(mtd, offs, len, &retlen, buf); 302} 303 304/* Scan read raw data from flash */ 305static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs, 306 size_t len) 307{ 308 struct mtd_oob_ops ops; 309 int res; 310 311 ops.mode = MTD_OPS_RAW; 312 ops.ooboffs = 0; 313 ops.ooblen = mtd->oobsize; 314 315 while (len > 0) { 316 ops.datbuf = buf; 317 ops.len = min(len, (size_t)mtd->writesize); 318 ops.oobbuf = buf + ops.len; 319 320 res = mtd_read_oob(mtd, offs, &ops); 321 322 if (res) 323 return res; 324 325 buf += mtd->oobsize + mtd->writesize; 326 len -= mtd->writesize; 327 offs += mtd->writesize; 328 } 329 return 0; 330} 331 332static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs, 333 size_t len, struct nand_bbt_descr *td) 334{ 335 if (td->options & NAND_BBT_NO_OOB) 336 return scan_read_raw_data(mtd, buf, offs, td); 337 else 338 return scan_read_raw_oob(mtd, buf, offs, len); 339} 340 341/* Scan write data with oob to flash */ 342static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len, 343 uint8_t *buf, uint8_t *oob) 344{ 345 struct mtd_oob_ops ops; 346 347 ops.mode = MTD_OPS_PLACE_OOB; 348 ops.ooboffs = 0; 349 ops.ooblen = mtd->oobsize; 350 ops.datbuf = buf; 351 ops.oobbuf = oob; 352 ops.len = len; 353 354 return mtd_write_oob(mtd, offs, &ops); 355} 356 357static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td) 358{ 359 u32 ver_offs = td->veroffs; 360 361 if (!(td->options & NAND_BBT_NO_OOB)) 362 ver_offs += mtd->writesize; 363 return ver_offs; 364} 365 366/** 367 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page 368 * @mtd: MTD device structure 369 * @buf: temporary buffer 370 * @td: descriptor for the bad block table 371 * @md: descriptor for the bad block table mirror 372 * 373 * Read the bad block table(s) for all chips starting at a given page. We 374 * assume that the bbt bits are in consecutive order. 375 */ 376static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf, 377 struct nand_bbt_descr *td, struct nand_bbt_descr *md) 378{ 379 struct nand_chip *this = mtd->priv; 380 381 /* Read the primary version, if available */ 382 if (td->options & NAND_BBT_VERSION) { 383 scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift, 384 mtd->writesize, td); 385 td->version[0] = buf[bbt_get_ver_offs(mtd, td)]; 386 pr_info("Bad block table at page %d, version 0x%02X\n", 387 td->pages[0], td->version[0]); 388 } 389 390 /* Read the mirror version, if available */ 391 if (md && (md->options & NAND_BBT_VERSION)) { 392 scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift, 393 mtd->writesize, td); 394 md->version[0] = buf[bbt_get_ver_offs(mtd, md)]; 395 pr_info("Bad block table at page %d, version 0x%02X\n", 396 md->pages[0], md->version[0]); 397 } 398 return 1; 399} 400 401/* Scan a given block full */ 402static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd, 403 loff_t offs, uint8_t *buf, size_t readlen, 404 int scanlen, int len) 405{ 406 int ret, j; 407 408 ret = scan_read_raw_oob(mtd, buf, offs, readlen); 409 /* Ignore ECC errors when checking for BBM */ 410 if (ret && !mtd_is_bitflip_or_eccerr(ret)) 411 return ret; 412 413 for (j = 0; j < len; j++, buf += scanlen) { 414 if (check_pattern(buf, scanlen, mtd->writesize, bd)) 415 return 1; 416 } 417 return 0; 418} 419 420/* Scan a given block partially */ 421static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd, 422 loff_t offs, uint8_t *buf, int len) 423{ 424 struct mtd_oob_ops ops; 425 int j, ret; 426 427 ops.ooblen = mtd->oobsize; 428 ops.oobbuf = buf; 429 ops.ooboffs = 0; 430 ops.datbuf = NULL; 431 ops.mode = MTD_OPS_PLACE_OOB; 432 433 for (j = 0; j < len; j++) { 434 /* 435 * Read the full oob until read_oob is fixed to handle single 436 * byte reads for 16 bit buswidth. 437 */ 438 ret = mtd_read_oob(mtd, offs, &ops); 439 /* Ignore ECC errors when checking for BBM */ 440 if (ret && !mtd_is_bitflip_or_eccerr(ret)) 441 return ret; 442 443 if (check_short_pattern(buf, bd)) 444 return 1; 445 446 offs += mtd->writesize; 447 } 448 return 0; 449} 450 451/** 452 * create_bbt - [GENERIC] Create a bad block table by scanning the device 453 * @mtd: MTD device structure 454 * @buf: temporary buffer 455 * @bd: descriptor for the good/bad block search pattern 456 * @chip: create the table for a specific chip, -1 read all chips; applies only 457 * if NAND_BBT_PERCHIP option is set 458 * 459 * Create a bad block table by scanning the device for the given good/bad block 460 * identify pattern. 461 */ 462static int create_bbt(struct mtd_info *mtd, uint8_t *buf, 463 struct nand_bbt_descr *bd, int chip) 464{ 465 struct nand_chip *this = mtd->priv; 466 int i, numblocks, len, scanlen; 467 int startblock; 468 loff_t from; 469 size_t readlen; 470 471 pr_info("Scanning device for bad blocks\n"); 472 473 if (bd->options & NAND_BBT_SCANALLPAGES) 474 len = 1 << (this->bbt_erase_shift - this->page_shift); 475 else if (bd->options & NAND_BBT_SCAN2NDPAGE) 476 len = 2; 477 else 478 len = 1; 479 480 if (!(bd->options & NAND_BBT_SCANEMPTY)) { 481 /* We need only read few bytes from the OOB area */ 482 scanlen = 0; 483 readlen = bd->len; 484 } else { 485 /* Full page content should be read */ 486 scanlen = mtd->writesize + mtd->oobsize; 487 readlen = len * mtd->writesize; 488 } 489 490 if (chip == -1) { 491 /* 492 * Note that numblocks is 2 * (real numblocks) here, see i+=2 493 * below as it makes shifting and masking less painful 494 */ 495 numblocks = mtd->size >> (this->bbt_erase_shift - 1); 496 startblock = 0; 497 from = 0; 498 } else { 499 if (chip >= this->numchips) { 500 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n", 501 chip + 1, this->numchips); 502 return -EINVAL; 503 } 504 numblocks = this->chipsize >> (this->bbt_erase_shift - 1); 505 startblock = chip * numblocks; 506 numblocks += startblock; 507 from = (loff_t)startblock << (this->bbt_erase_shift - 1); 508 } 509 510 if (this->bbt_options & NAND_BBT_SCANLASTPAGE) 511 from += mtd->erasesize - (mtd->writesize * len); 512 513 for (i = startblock; i < numblocks;) { 514 int ret; 515 516 BUG_ON(bd->options & NAND_BBT_NO_OOB); 517 518 if (bd->options & NAND_BBT_SCANALLPAGES) 519 ret = scan_block_full(mtd, bd, from, buf, readlen, 520 scanlen, len); 521 else 522 ret = scan_block_fast(mtd, bd, from, buf, len); 523 524 if (ret < 0) 525 return ret; 526 527 if (ret) { 528 this->bbt[i >> 3] |= 0x03 << (i & 0x6); 529 pr_warn("Bad eraseblock %d at 0x%012llx\n", 530 i >> 1, (unsigned long long)from); 531 mtd->ecc_stats.badblocks++; 532 } 533 534 i += 2; 535 from += (1 << this->bbt_erase_shift); 536 } 537 return 0; 538} 539 540/** 541 * search_bbt - [GENERIC] scan the device for a specific bad block table 542 * @mtd: MTD device structure 543 * @buf: temporary buffer 544 * @td: descriptor for the bad block table 545 * 546 * Read the bad block table by searching for a given ident pattern. Search is 547 * preformed either from the beginning up or from the end of the device 548 * downwards. The search starts always at the start of a block. If the option 549 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains 550 * the bad block information of this chip. This is necessary to provide support 551 * for certain DOC devices. 552 * 553 * The bbt ident pattern resides in the oob area of the first page in a block. 554 */ 555static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td) 556{ 557 struct nand_chip *this = mtd->priv; 558 int i, chips; 559 int bits, startblock, block, dir; 560 int scanlen = mtd->writesize + mtd->oobsize; 561 int bbtblocks; 562 int blocktopage = this->bbt_erase_shift - this->page_shift; 563 564 /* Search direction top -> down? */ 565 if (td->options & NAND_BBT_LASTBLOCK) { 566 startblock = (mtd->size >> this->bbt_erase_shift) - 1; 567 dir = -1; 568 } else { 569 startblock = 0; 570 dir = 1; 571 } 572 573 /* Do we have a bbt per chip? */ 574 if (td->options & NAND_BBT_PERCHIP) { 575 chips = this->numchips; 576 bbtblocks = this->chipsize >> this->bbt_erase_shift; 577 startblock &= bbtblocks - 1; 578 } else { 579 chips = 1; 580 bbtblocks = mtd->size >> this->bbt_erase_shift; 581 } 582 583 /* Number of bits for each erase block in the bbt */ 584 bits = td->options & NAND_BBT_NRBITS_MSK; 585 586 for (i = 0; i < chips; i++) { 587 /* Reset version information */ 588 td->version[i] = 0; 589 td->pages[i] = -1; 590 /* Scan the maximum number of blocks */ 591 for (block = 0; block < td->maxblocks; block++) { 592 593 int actblock = startblock + dir * block; 594 loff_t offs = (loff_t)actblock << this->bbt_erase_shift; 595 596 /* Read first page */ 597 scan_read_raw(mtd, buf, offs, mtd->writesize, td); 598 if (!check_pattern(buf, scanlen, mtd->writesize, td)) { 599 td->pages[i] = actblock << blocktopage; 600 if (td->options & NAND_BBT_VERSION) { 601 offs = bbt_get_ver_offs(mtd, td); 602 td->version[i] = buf[offs]; 603 } 604 break; 605 } 606 } 607 startblock += this->chipsize >> this->bbt_erase_shift; 608 } 609 /* Check, if we found a bbt for each requested chip */ 610 for (i = 0; i < chips; i++) { 611 if (td->pages[i] == -1) 612 pr_warn("Bad block table not found for chip %d\n", i); 613 else 614 pr_info("Bad block table found at page %d, version " 615 "0x%02X\n", td->pages[i], td->version[i]); 616 } 617 return 0; 618} 619 620/** 621 * search_read_bbts - [GENERIC] scan the device for bad block table(s) 622 * @mtd: MTD device structure 623 * @buf: temporary buffer 624 * @td: descriptor for the bad block table 625 * @md: descriptor for the bad block table mirror 626 * 627 * Search and read the bad block table(s). 628 */ 629static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md) 630{ 631 /* Search the primary table */ 632 search_bbt(mtd, buf, td); 633 634 /* Search the mirror table */ 635 if (md) 636 search_bbt(mtd, buf, md); 637 638 /* Force result check */ 639 return 1; 640} 641 642/** 643 * write_bbt - [GENERIC] (Re)write the bad block table 644 * @mtd: MTD device structure 645 * @buf: temporary buffer 646 * @td: descriptor for the bad block table 647 * @md: descriptor for the bad block table mirror 648 * @chipsel: selector for a specific chip, -1 for all 649 * 650 * (Re)write the bad block table. 651 */ 652static int write_bbt(struct mtd_info *mtd, uint8_t *buf, 653 struct nand_bbt_descr *td, struct nand_bbt_descr *md, 654 int chipsel) 655{ 656 struct nand_chip *this = mtd->priv; 657 struct erase_info einfo; 658 int i, j, res, chip = 0; 659 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk; 660 int nrchips, bbtoffs, pageoffs, ooboffs; 661 uint8_t msk[4]; 662 uint8_t rcode = td->reserved_block_code; 663 size_t retlen, len = 0; 664 loff_t to; 665 struct mtd_oob_ops ops; 666 667 ops.ooblen = mtd->oobsize; 668 ops.ooboffs = 0; 669 ops.datbuf = NULL; 670 ops.mode = MTD_OPS_PLACE_OOB; 671 672 if (!rcode) 673 rcode = 0xff; 674 /* Write bad block table per chip rather than per device? */ 675 if (td->options & NAND_BBT_PERCHIP) { 676 numblocks = (int)(this->chipsize >> this->bbt_erase_shift); 677 /* Full device write or specific chip? */ 678 if (chipsel == -1) { 679 nrchips = this->numchips; 680 } else { 681 nrchips = chipsel + 1; 682 chip = chipsel; 683 } 684 } else { 685 numblocks = (int)(mtd->size >> this->bbt_erase_shift); 686 nrchips = 1; 687 } 688 689 /* Loop through the chips */ 690 for (; chip < nrchips; chip++) { 691 /* 692 * There was already a version of the table, reuse the page 693 * This applies for absolute placement too, as we have the 694 * page nr. in td->pages. 695 */ 696 if (td->pages[chip] != -1) { 697 page = td->pages[chip]; 698 goto write; 699 } 700 701 /* 702 * Automatic placement of the bad block table. Search direction 703 * top -> down? 704 */ 705 if (td->options & NAND_BBT_LASTBLOCK) { 706 startblock = numblocks * (chip + 1) - 1; 707 dir = -1; 708 } else { 709 startblock = chip * numblocks; 710 dir = 1; 711 } 712 713 for (i = 0; i < td->maxblocks; i++) { 714 int block = startblock + dir * i; 715 /* Check, if the block is bad */ 716 switch ((this->bbt[block >> 2] >> 717 (2 * (block & 0x03))) & 0x03) { 718 case 0x01: 719 case 0x03: 720 continue; 721 } 722 page = block << 723 (this->bbt_erase_shift - this->page_shift); 724 /* Check, if the block is used by the mirror table */ 725 if (!md || md->pages[chip] != page) 726 goto write; 727 } 728 pr_err("No space left to write bad block table\n"); 729 return -ENOSPC; 730 write: 731 732 /* Set up shift count and masks for the flash table */ 733 bits = td->options & NAND_BBT_NRBITS_MSK; 734 msk[2] = ~rcode; 735 switch (bits) { 736 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; 737 msk[3] = 0x01; 738 break; 739 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; 740 msk[3] = 0x03; 741 break; 742 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; 743 msk[3] = 0x0f; 744 break; 745 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; 746 msk[3] = 0xff; 747 break; 748 default: return -EINVAL; 749 } 750 751 bbtoffs = chip * (numblocks >> 2); 752 753 to = ((loff_t)page) << this->page_shift; 754 755 /* Must we save the block contents? */ 756 if (td->options & NAND_BBT_SAVECONTENT) { 757 /* Make it block aligned */ 758 to &= ~((loff_t)((1 << this->bbt_erase_shift) - 1)); 759 len = 1 << this->bbt_erase_shift; 760 res = mtd_read(mtd, to, len, &retlen, buf); 761 if (res < 0) { 762 if (retlen != len) { 763 pr_info("nand_bbt: error reading block " 764 "for writing the bad block table\n"); 765 return res; 766 } 767 pr_warn("nand_bbt: ECC error while reading " 768 "block for writing bad block table\n"); 769 } 770 /* Read oob data */ 771 ops.ooblen = (len >> this->page_shift) * mtd->oobsize; 772 ops.oobbuf = &buf[len]; 773 res = mtd_read_oob(mtd, to + mtd->writesize, &ops); 774 if (res < 0 || ops.oobretlen != ops.ooblen) 775 goto outerr; 776 777 /* Calc the byte offset in the buffer */ 778 pageoffs = page - (int)(to >> this->page_shift); 779 offs = pageoffs << this->page_shift; 780 /* Preset the bbt area with 0xff */ 781 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft)); 782 ooboffs = len + (pageoffs * mtd->oobsize); 783 784 } else if (td->options & NAND_BBT_NO_OOB) { 785 ooboffs = 0; 786 offs = td->len; 787 /* The version byte */ 788 if (td->options & NAND_BBT_VERSION) 789 offs++; 790 /* Calc length */ 791 len = (size_t)(numblocks >> sft); 792 len += offs; 793 /* Make it page aligned! */ 794 len = ALIGN(len, mtd->writesize); 795 /* Preset the buffer with 0xff */ 796 memset(buf, 0xff, len); 797 /* Pattern is located at the begin of first page */ 798 memcpy(buf, td->pattern, td->len); 799 } else { 800 /* Calc length */ 801 len = (size_t)(numblocks >> sft); 802 /* Make it page aligned! */ 803 len = ALIGN(len, mtd->writesize); 804 /* Preset the buffer with 0xff */ 805 memset(buf, 0xff, len + 806 (len >> this->page_shift)* mtd->oobsize); 807 offs = 0; 808 ooboffs = len; 809 /* Pattern is located in oob area of first page */ 810 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len); 811 } 812 813 if (td->options & NAND_BBT_VERSION) 814 buf[ooboffs + td->veroffs] = td->version[chip]; 815 816 /* Walk through the memory table */ 817 for (i = 0; i < numblocks;) { 818 uint8_t dat; 819 dat = this->bbt[bbtoffs + (i >> 2)]; 820 for (j = 0; j < 4; j++, i++) { 821 int sftcnt = (i << (3 - sft)) & sftmsk; 822 /* Do not store the reserved bbt blocks! */ 823 buf[offs + (i >> sft)] &= 824 ~(msk[dat & 0x03] << sftcnt); 825 dat >>= 2; 826 } 827 } 828 829 memset(&einfo, 0, sizeof(einfo)); 830 einfo.mtd = mtd; 831 einfo.addr = to; 832 einfo.len = 1 << this->bbt_erase_shift; 833 res = nand_erase_nand(mtd, &einfo, 1); 834 if (res < 0) 835 goto outerr; 836 837 res = scan_write_bbt(mtd, to, len, buf, 838 td->options & NAND_BBT_NO_OOB ? NULL : 839 &buf[len]); 840 if (res < 0) 841 goto outerr; 842 843 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n", 844 (unsigned long long)to, td->version[chip]); 845 846 /* Mark it as used */ 847 td->pages[chip] = page; 848 } 849 return 0; 850 851 outerr: 852 pr_warn("nand_bbt: error while writing bad block table %d\n", res); 853 return res; 854} 855 856/** 857 * nand_memory_bbt - [GENERIC] create a memory based bad block table 858 * @mtd: MTD device structure 859 * @bd: descriptor for the good/bad block search pattern 860 * 861 * The function creates a memory based bbt by scanning the device for 862 * manufacturer / software marked good / bad blocks. 863 */ 864static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) 865{ 866 struct nand_chip *this = mtd->priv; 867 868 bd->options &= ~NAND_BBT_SCANEMPTY; 869 return create_bbt(mtd, this->buffers->databuf, bd, -1); 870} 871 872/** 873 * check_create - [GENERIC] create and write bbt(s) if necessary 874 * @mtd: MTD device structure 875 * @buf: temporary buffer 876 * @bd: descriptor for the good/bad block search pattern 877 * 878 * The function checks the results of the previous call to read_bbt and creates 879 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found 880 * for the chip/device. Update is necessary if one of the tables is missing or 881 * the version nr. of one table is less than the other. 882 */ 883static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd) 884{ 885 int i, chips, writeops, create, chipsel, res, res2; 886 struct nand_chip *this = mtd->priv; 887 struct nand_bbt_descr *td = this->bbt_td; 888 struct nand_bbt_descr *md = this->bbt_md; 889 struct nand_bbt_descr *rd, *rd2; 890 891 /* Do we have a bbt per chip? */ 892 if (td->options & NAND_BBT_PERCHIP) 893 chips = this->numchips; 894 else 895 chips = 1; 896 897 for (i = 0; i < chips; i++) { 898 writeops = 0; 899 create = 0; 900 rd = NULL; 901 rd2 = NULL; 902 res = res2 = 0; 903 /* Per chip or per device? */ 904 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1; 905 /* Mirrored table available? */ 906 if (md) { 907 if (td->pages[i] == -1 && md->pages[i] == -1) { 908 create = 1; 909 writeops = 0x03; 910 } else if (td->pages[i] == -1) { 911 rd = md; 912 writeops = 0x01; 913 } else if (md->pages[i] == -1) { 914 rd = td; 915 writeops = 0x02; 916 } else if (td->version[i] == md->version[i]) { 917 rd = td; 918 if (!(td->options & NAND_BBT_VERSION)) 919 rd2 = md; 920 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) { 921 rd = td; 922 writeops = 0x02; 923 } else { 924 rd = md; 925 writeops = 0x01; 926 } 927 } else { 928 if (td->pages[i] == -1) { 929 create = 1; 930 writeops = 0x01; 931 } else { 932 rd = td; 933 } 934 } 935 936 if (create) { 937 /* Create the bad block table by scanning the device? */ 938 if (!(td->options & NAND_BBT_CREATE)) 939 continue; 940 941 /* Create the table in memory by scanning the chip(s) */ 942 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY)) 943 create_bbt(mtd, buf, bd, chipsel); 944 945 td->version[i] = 1; 946 if (md) 947 md->version[i] = 1; 948 } 949 950 /* Read back first? */ 951 if (rd) { 952 res = read_abs_bbt(mtd, buf, rd, chipsel); 953 if (mtd_is_eccerr(res)) { 954 /* Mark table as invalid */ 955 rd->pages[i] = -1; 956 rd->version[i] = 0; 957 i--; 958 continue; 959 } 960 } 961 /* If they weren't versioned, read both */ 962 if (rd2) { 963 res2 = read_abs_bbt(mtd, buf, rd2, chipsel); 964 if (mtd_is_eccerr(res2)) { 965 /* Mark table as invalid */ 966 rd2->pages[i] = -1; 967 rd2->version[i] = 0; 968 i--; 969 continue; 970 } 971 } 972 973 /* Scrub the flash table(s)? */ 974 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2)) 975 writeops = 0x03; 976 977 /* Update version numbers before writing */ 978 if (md) { 979 td->version[i] = max(td->version[i], md->version[i]); 980 md->version[i] = td->version[i]; 981 } 982 983 /* Write the bad block table to the device? */ 984 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { 985 res = write_bbt(mtd, buf, td, md, chipsel); 986 if (res < 0) 987 return res; 988 } 989 990 /* Write the mirror bad block table to the device? */ 991 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) { 992 res = write_bbt(mtd, buf, md, td, chipsel); 993 if (res < 0) 994 return res; 995 } 996 } 997 return 0; 998} 999 1000/** 1001 * mark_bbt_regions - [GENERIC] mark the bad block table regions 1002 * @mtd: MTD device structure 1003 * @td: bad block table descriptor 1004 * 1005 * The bad block table regions are marked as "bad" to prevent accidental 1006 * erasures / writes. The regions are identified by the mark 0x02. 1007 */ 1008static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) 1009{ 1010 struct nand_chip *this = mtd->priv; 1011 int i, j, chips, block, nrblocks, update; 1012 uint8_t oldval, newval; 1013 1014 /* Do we have a bbt per chip? */ 1015 if (td->options & NAND_BBT_PERCHIP) { 1016 chips = this->numchips; 1017 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift); 1018 } else { 1019 chips = 1; 1020 nrblocks = (int)(mtd->size >> this->bbt_erase_shift); 1021 } 1022 1023 for (i = 0; i < chips; i++) { 1024 if ((td->options & NAND_BBT_ABSPAGE) || 1025 !(td->options & NAND_BBT_WRITE)) { 1026 if (td->pages[i] == -1) 1027 continue; 1028 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift); 1029 block <<= 1; 1030 oldval = this->bbt[(block >> 3)]; 1031 newval = oldval | (0x2 << (block & 0x06)); 1032 this->bbt[(block >> 3)] = newval; 1033 if ((oldval != newval) && td->reserved_block_code) 1034 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1)); 1035 continue; 1036 } 1037 update = 0; 1038 if (td->options & NAND_BBT_LASTBLOCK) 1039 block = ((i + 1) * nrblocks) - td->maxblocks; 1040 else 1041 block = i * nrblocks; 1042 block <<= 1; 1043 for (j = 0; j < td->maxblocks; j++) { 1044 oldval = this->bbt[(block >> 3)]; 1045 newval = oldval | (0x2 << (block & 0x06)); 1046 this->bbt[(block >> 3)] = newval; 1047 if (oldval != newval) 1048 update = 1; 1049 block += 2; 1050 } 1051 /* 1052 * If we want reserved blocks to be recorded to flash, and some 1053 * new ones have been marked, then we need to update the stored 1054 * bbts. This should only happen once. 1055 */ 1056 if (update && td->reserved_block_code) 1057 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1)); 1058 } 1059} 1060 1061/** 1062 * verify_bbt_descr - verify the bad block description 1063 * @mtd: MTD device structure 1064 * @bd: the table to verify 1065 * 1066 * This functions performs a few sanity checks on the bad block description 1067 * table. 1068 */ 1069static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd) 1070{ 1071 struct nand_chip *this = mtd->priv; 1072 u32 pattern_len; 1073 u32 bits; 1074 u32 table_size; 1075 1076 if (!bd) 1077 return; 1078 1079 pattern_len = bd->len; 1080 bits = bd->options & NAND_BBT_NRBITS_MSK; 1081 1082 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) && 1083 !(this->bbt_options & NAND_BBT_USE_FLASH)); 1084 BUG_ON(!bits); 1085 1086 if (bd->options & NAND_BBT_VERSION) 1087 pattern_len++; 1088 1089 if (bd->options & NAND_BBT_NO_OOB) { 1090 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH)); 1091 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB)); 1092 BUG_ON(bd->offs); 1093 if (bd->options & NAND_BBT_VERSION) 1094 BUG_ON(bd->veroffs != bd->len); 1095 BUG_ON(bd->options & NAND_BBT_SAVECONTENT); 1096 } 1097 1098 if (bd->options & NAND_BBT_PERCHIP) 1099 table_size = this->chipsize >> this->bbt_erase_shift; 1100 else 1101 table_size = mtd->size >> this->bbt_erase_shift; 1102 table_size >>= 3; 1103 table_size *= bits; 1104 if (bd->options & NAND_BBT_NO_OOB) 1105 table_size += pattern_len; 1106 BUG_ON(table_size > (1 << this->bbt_erase_shift)); 1107} 1108 1109/** 1110 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s) 1111 * @mtd: MTD device structure 1112 * @bd: descriptor for the good/bad block search pattern 1113 * 1114 * The function checks, if a bad block table(s) is/are already available. If 1115 * not it scans the device for manufacturer marked good / bad blocks and writes 1116 * the bad block table(s) to the selected place. 1117 * 1118 * The bad block table memory is allocated here. It must be freed by calling 1119 * the nand_free_bbt function. 1120 */ 1121int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) 1122{ 1123 struct nand_chip *this = mtd->priv; 1124 int len, res = 0; 1125 uint8_t *buf; 1126 struct nand_bbt_descr *td = this->bbt_td; 1127 struct nand_bbt_descr *md = this->bbt_md; 1128 1129 len = mtd->size >> (this->bbt_erase_shift + 2); 1130 /* 1131 * Allocate memory (2bit per block) and clear the memory bad block 1132 * table. 1133 */ 1134 this->bbt = kzalloc(len, GFP_KERNEL); 1135 if (!this->bbt) 1136 return -ENOMEM; 1137 1138 /* 1139 * If no primary table decriptor is given, scan the device to build a 1140 * memory based bad block table. 1141 */ 1142 if (!td) { 1143 if ((res = nand_memory_bbt(mtd, bd))) { 1144 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n"); 1145 kfree(this->bbt); 1146 this->bbt = NULL; 1147 } 1148 return res; 1149 } 1150 verify_bbt_descr(mtd, td); 1151 verify_bbt_descr(mtd, md); 1152 1153 /* Allocate a temporary buffer for one eraseblock incl. oob */ 1154 len = (1 << this->bbt_erase_shift); 1155 len += (len >> this->page_shift) * mtd->oobsize; 1156 buf = vmalloc(len); 1157 if (!buf) { 1158 kfree(this->bbt); 1159 this->bbt = NULL; 1160 return -ENOMEM; 1161 } 1162 1163 /* Is the bbt at a given page? */ 1164 if (td->options & NAND_BBT_ABSPAGE) { 1165 res = read_abs_bbts(mtd, buf, td, md); 1166 } else { 1167 /* Search the bad block table using a pattern in oob */ 1168 res = search_read_bbts(mtd, buf, td, md); 1169 } 1170 1171 if (res) 1172 res = check_create(mtd, buf, bd); 1173 1174 /* Prevent the bbt regions from erasing / writing */ 1175 mark_bbt_region(mtd, td); 1176 if (md) 1177 mark_bbt_region(mtd, md); 1178 1179 vfree(buf); 1180 return res; 1181} 1182 1183/** 1184 * nand_update_bbt - [NAND Interface] update bad block table(s) 1185 * @mtd: MTD device structure 1186 * @offs: the offset of the newly marked block 1187 * 1188 * The function updates the bad block table(s). 1189 */ 1190int nand_update_bbt(struct mtd_info *mtd, loff_t offs) 1191{ 1192 struct nand_chip *this = mtd->priv; 1193 int len, res = 0; 1194 int chip, chipsel; 1195 uint8_t *buf; 1196 struct nand_bbt_descr *td = this->bbt_td; 1197 struct nand_bbt_descr *md = this->bbt_md; 1198 1199 if (!this->bbt || !td) 1200 return -EINVAL; 1201 1202 /* Allocate a temporary buffer for one eraseblock incl. oob */ 1203 len = (1 << this->bbt_erase_shift); 1204 len += (len >> this->page_shift) * mtd->oobsize; 1205 buf = kmalloc(len, GFP_KERNEL); 1206 if (!buf) 1207 return -ENOMEM; 1208 1209 /* Do we have a bbt per chip? */ 1210 if (td->options & NAND_BBT_PERCHIP) { 1211 chip = (int)(offs >> this->chip_shift); 1212 chipsel = chip; 1213 } else { 1214 chip = 0; 1215 chipsel = -1; 1216 } 1217 1218 td->version[chip]++; 1219 if (md) 1220 md->version[chip]++; 1221 1222 /* Write the bad block table to the device? */ 1223 if (td->options & NAND_BBT_WRITE) { 1224 res = write_bbt(mtd, buf, td, md, chipsel); 1225 if (res < 0) 1226 goto out; 1227 } 1228 /* Write the mirror bad block table to the device? */ 1229 if (md && (md->options & NAND_BBT_WRITE)) { 1230 res = write_bbt(mtd, buf, md, td, chipsel); 1231 } 1232 1233 out: 1234 kfree(buf); 1235 return res; 1236} 1237 1238/* 1239 * Define some generic bad / good block scan pattern which are used 1240 * while scanning a device for factory marked good / bad blocks. 1241 */ 1242static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; 1243 1244static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 }; 1245 1246static struct nand_bbt_descr agand_flashbased = { 1247 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES, 1248 .offs = 0x20, 1249 .len = 6, 1250 .pattern = scan_agand_pattern 1251}; 1252 1253/* Generic flash bbt descriptors */ 1254static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' }; 1255static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' }; 1256 1257static struct nand_bbt_descr bbt_main_descr = { 1258 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE 1259 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP, 1260 .offs = 8, 1261 .len = 4, 1262 .veroffs = 12, 1263 .maxblocks = 4, 1264 .pattern = bbt_pattern 1265}; 1266 1267static struct nand_bbt_descr bbt_mirror_descr = { 1268 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE 1269 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP, 1270 .offs = 8, 1271 .len = 4, 1272 .veroffs = 12, 1273 .maxblocks = 4, 1274 .pattern = mirror_pattern 1275}; 1276 1277static struct nand_bbt_descr bbt_main_no_bbt_descr = { 1278 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE 1279 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP 1280 | NAND_BBT_NO_OOB, 1281 .len = 4, 1282 .veroffs = 4, 1283 .maxblocks = 4, 1284 .pattern = bbt_pattern 1285}; 1286 1287static struct nand_bbt_descr bbt_mirror_no_bbt_descr = { 1288 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE 1289 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP 1290 | NAND_BBT_NO_OOB, 1291 .len = 4, 1292 .veroffs = 4, 1293 .maxblocks = 4, 1294 .pattern = mirror_pattern 1295}; 1296 1297#define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB) 1298/** 1299 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure 1300 * @this: NAND chip to create descriptor for 1301 * 1302 * This function allocates and initializes a nand_bbt_descr for BBM detection 1303 * based on the properties of @this. The new descriptor is stored in 1304 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when 1305 * passed to this function. 1306 */ 1307static int nand_create_badblock_pattern(struct nand_chip *this) 1308{ 1309 struct nand_bbt_descr *bd; 1310 if (this->badblock_pattern) { 1311 pr_warn("Bad block pattern already allocated; not replacing\n"); 1312 return -EINVAL; 1313 } 1314 bd = kzalloc(sizeof(*bd), GFP_KERNEL); 1315 if (!bd) 1316 return -ENOMEM; 1317 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK; 1318 bd->offs = this->badblockpos; 1319 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1; 1320 bd->pattern = scan_ff_pattern; 1321 bd->options |= NAND_BBT_DYNAMICSTRUCT; 1322 this->badblock_pattern = bd; 1323 return 0; 1324} 1325 1326/** 1327 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device 1328 * @mtd: MTD device structure 1329 * 1330 * This function selects the default bad block table support for the device and 1331 * calls the nand_scan_bbt function. 1332 */ 1333int nand_default_bbt(struct mtd_info *mtd) 1334{ 1335 struct nand_chip *this = mtd->priv; 1336 1337 /* 1338 * Default for AG-AND. We must use a flash based bad block table as the 1339 * devices have factory marked _good_ blocks. Erasing those blocks 1340 * leads to loss of the good / bad information, so we _must_ store this 1341 * information in a good / bad table during startup. 1342 */ 1343 if (this->options & NAND_IS_AND) { 1344 /* Use the default pattern descriptors */ 1345 if (!this->bbt_td) { 1346 this->bbt_td = &bbt_main_descr; 1347 this->bbt_md = &bbt_mirror_descr; 1348 } 1349 this->bbt_options |= NAND_BBT_USE_FLASH; 1350 return nand_scan_bbt(mtd, &agand_flashbased); 1351 } 1352 1353 /* Is a flash based bad block table requested? */ 1354 if (this->bbt_options & NAND_BBT_USE_FLASH) { 1355 /* Use the default pattern descriptors */ 1356 if (!this->bbt_td) { 1357 if (this->bbt_options & NAND_BBT_NO_OOB) { 1358 this->bbt_td = &bbt_main_no_bbt_descr; 1359 this->bbt_md = &bbt_mirror_no_bbt_descr; 1360 } else { 1361 this->bbt_td = &bbt_main_descr; 1362 this->bbt_md = &bbt_mirror_descr; 1363 } 1364 } 1365 } else { 1366 this->bbt_td = NULL; 1367 this->bbt_md = NULL; 1368 } 1369 1370 if (!this->badblock_pattern) 1371 nand_create_badblock_pattern(this); 1372 1373 return nand_scan_bbt(mtd, this->badblock_pattern); 1374} 1375 1376/** 1377 * nand_isbad_bbt - [NAND Interface] Check if a block is bad 1378 * @mtd: MTD device structure 1379 * @offs: offset in the device 1380 * @allowbbt: allow access to bad block table region 1381 */ 1382int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) 1383{ 1384 struct nand_chip *this = mtd->priv; 1385 int block; 1386 uint8_t res; 1387 1388 /* Get block number * 2 */ 1389 block = (int)(offs >> (this->bbt_erase_shift - 1)); 1390 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03; 1391 1392 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: " 1393 "(block %d) 0x%02x\n", 1394 (unsigned int)offs, block >> 1, res); 1395 1396 switch ((int)res) { 1397 case 0x00: 1398 return 0; 1399 case 0x01: 1400 return 1; 1401 case 0x02: 1402 return allowbbt ? 0 : 1; 1403 } 1404 return 1; 1405} 1406 1407EXPORT_SYMBOL(nand_scan_bbt); 1408EXPORT_SYMBOL(nand_default_bbt); 1409