2 * drivers/mtd/nand_bbt.c
5 * Bad block table support for the NAND driver
7 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
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.
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
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, then 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27 * If one of the BBTs is out of date or does not exist it is (re)created.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.
31 * For manufacturer created BBTs like the one found on M-SYS DOC devices
32 * the BBT is searched and read but never created
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.
43 * The table uses 2 bits per block
45 * 00b: block is factory marked bad
46 * 01b, 10b: block is marked bad due to wear
48 * The memory bad block table uses the following scheme:
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
54 * Multichip devices like DOC store the bad block info per floor.
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
64 #include <linux/compat.h>
65 #include <linux/mtd/mtd.h>
66 #include <linux/mtd/bbm.h>
67 #include <linux/mtd/nand.h>
68 #include <linux/mtd/nand_ecc.h>
69 #include <linux/bitops.h>
70 #include <linux/string.h>
72 #include <asm/errno.h>
74 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
76 if (memcmp(buf, td->pattern, td->len))
82 * check_pattern - [GENERIC] check if a pattern is in the buffer
83 * @buf: the buffer to search
84 * @len: the length of buffer to search
85 * @paglen: the pagelength
86 * @td: search pattern descriptor
88 * Check for a pattern at the given place. Used to search bad block tables and
89 * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if
90 * all bytes except the pattern area contain 0xff.
92 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
97 if (td->options & NAND_BBT_NO_OOB)
98 return check_pattern_no_oob(buf, td);
100 end = paglen + td->offs;
101 if (td->options & NAND_BBT_SCANEMPTY)
102 if (memchr_inv(p, 0xff, end))
106 /* Compare the pattern */
107 if (memcmp(p, td->pattern, td->len))
110 if (td->options & NAND_BBT_SCANEMPTY) {
113 if (memchr_inv(p, 0xff, len - end))
120 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
121 * @buf: the buffer to search
122 * @td: search pattern descriptor
124 * Check for a pattern at the given place. Used to search bad block tables and
125 * good / bad block identifiers. Same as check_pattern, but no optional empty
128 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
130 /* Compare the pattern */
131 if (memcmp(buf + td->offs, td->pattern, td->len))
137 * add_marker_len - compute the length of the marker in data area
138 * @td: BBT descriptor used for computation
140 * The length will be 0 if the marker is located in OOB area.
142 static u32 add_marker_len(struct nand_bbt_descr *td)
146 if (!(td->options & NAND_BBT_NO_OOB))
150 if (td->options & NAND_BBT_VERSION)
156 * read_bbt - [GENERIC] Read the bad block table starting from page
157 * @mtd: MTD device structure
158 * @buf: temporary buffer
159 * @page: the starting page
160 * @num: the number of bbt descriptors to read
161 * @td: the bbt describtion table
162 * @offs: offset in the memory table
164 * Read the bad block table starting from page.
166 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
167 struct nand_bbt_descr *td, int offs)
169 int res, ret = 0, i, j, act = 0;
170 struct nand_chip *this = mtd->priv;
171 size_t retlen, len, totlen;
173 int bits = td->options & NAND_BBT_NRBITS_MSK;
174 uint8_t msk = (uint8_t)((1 << bits) - 1);
176 int reserved_block_code = td->reserved_block_code;
178 totlen = (num * bits) >> 3;
179 marker_len = add_marker_len(td);
180 from = ((loff_t)page) << this->page_shift;
183 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
186 * In case the BBT marker is not in the OOB area it
187 * will be just in the first page.
193 res = mtd_read(mtd, from, len, &retlen, buf);
195 if (mtd_is_eccerr(res)) {
196 pr_info("nand_bbt: ECC error in BBT at "
197 "0x%012llx\n", from & ~mtd->writesize);
199 } else if (mtd_is_bitflip(res)) {
200 pr_info("nand_bbt: corrected error in BBT at "
201 "0x%012llx\n", from & ~mtd->writesize);
204 pr_info("nand_bbt: error reading BBT\n");
210 for (i = 0; i < len; i++) {
211 uint8_t dat = buf[i];
212 for (j = 0; j < 8; j += bits, act += 2) {
213 uint8_t tmp = (dat >> j) & msk;
216 if (reserved_block_code && (tmp == reserved_block_code)) {
217 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
218 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
219 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
220 mtd->ecc_stats.bbtblocks++;
223 pr_info("nand_read_bbt: Bad block at 0x%012llx\n",
224 (loff_t)((offs << 2) + (act >> 1))
225 << this->bbt_erase_shift);
226 /* Factory marked bad or worn out? */
228 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
230 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
231 mtd->ecc_stats.badblocks++;
241 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
242 * @mtd: MTD device structure
243 * @buf: temporary buffer
244 * @td: descriptor for the bad block table
245 * @chip: read the table for a specific chip, -1 read all chips; applies only if
246 * NAND_BBT_PERCHIP option is set
248 * Read the bad block table for all chips starting at a given page. We assume
249 * that the bbt bits are in consecutive order.
251 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
253 struct nand_chip *this = mtd->priv;
256 if (td->options & NAND_BBT_PERCHIP) {
258 for (i = 0; i < this->numchips; i++) {
259 if (chip == -1 || chip == i)
260 res = read_bbt(mtd, buf, td->pages[i],
261 this->chipsize >> this->bbt_erase_shift,
265 offs += this->chipsize >> (this->bbt_erase_shift + 2);
268 res = read_bbt(mtd, buf, td->pages[0],
269 mtd->size >> this->bbt_erase_shift, td, 0);
276 /* BBT marker is in the first page, no OOB */
277 static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
278 struct nand_bbt_descr *td)
284 if (td->options & NAND_BBT_VERSION)
287 return mtd_read(mtd, offs, len, &retlen, buf);
291 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
292 * @mtd: MTD device structure
293 * @buf: temporary buffer
294 * @offs: offset at which to scan
295 * @len: length of data region to read
297 * Scan read data from data+OOB. May traverse multiple pages, interleaving
298 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
299 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
301 static int scan_read_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
304 struct mtd_oob_ops ops;
307 ops.mode = MTD_OPS_PLACE_OOB;
309 ops.ooblen = mtd->oobsize;
313 ops.len = min(len, (size_t)mtd->writesize);
314 ops.oobbuf = buf + ops.len;
316 res = mtd_read_oob(mtd, offs, &ops);
318 if (!mtd_is_bitflip_or_eccerr(res))
320 else if (mtd_is_eccerr(res) || !ret)
324 buf += mtd->oobsize + mtd->writesize;
325 len -= mtd->writesize;
326 offs += mtd->writesize;
331 static int scan_read(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
332 size_t len, struct nand_bbt_descr *td)
334 if (td->options & NAND_BBT_NO_OOB)
335 return scan_read_data(mtd, buf, offs, td);
337 return scan_read_oob(mtd, buf, offs, len);
340 /* Scan write data with oob to flash */
341 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
342 uint8_t *buf, uint8_t *oob)
344 struct mtd_oob_ops ops;
346 ops.mode = MTD_OPS_PLACE_OOB;
348 ops.ooblen = mtd->oobsize;
353 return mtd_write_oob(mtd, offs, &ops);
356 static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
358 u32 ver_offs = td->veroffs;
360 if (!(td->options & NAND_BBT_NO_OOB))
361 ver_offs += mtd->writesize;
366 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
367 * @mtd: MTD device structure
368 * @buf: temporary buffer
369 * @td: descriptor for the bad block table
370 * @md: descriptor for the bad block table mirror
372 * Read the bad block table(s) for all chips starting at a given page. We
373 * assume that the bbt bits are in consecutive order.
375 static void read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
376 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
378 struct nand_chip *this = mtd->priv;
380 /* Read the primary version, if available */
381 if (td->options & NAND_BBT_VERSION) {
382 scan_read(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
384 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
385 pr_info("Bad block table at page %d, version 0x%02X\n",
386 td->pages[0], td->version[0]);
389 /* Read the mirror version, if available */
390 if (md && (md->options & NAND_BBT_VERSION)) {
391 scan_read(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
393 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
394 pr_info("Bad block table at page %d, version 0x%02X\n",
395 md->pages[0], md->version[0]);
399 /* Scan a given block full */
400 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
401 loff_t offs, uint8_t *buf, size_t readlen,
402 int scanlen, int numpages)
406 ret = scan_read_oob(mtd, buf, offs, readlen);
407 /* Ignore ECC errors when checking for BBM */
408 if (ret && !mtd_is_bitflip_or_eccerr(ret))
411 for (j = 0; j < numpages; j++, buf += scanlen) {
412 if (check_pattern(buf, scanlen, mtd->writesize, bd))
418 /* Scan a given block partially */
419 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
420 loff_t offs, uint8_t *buf, int numpages)
422 struct mtd_oob_ops ops;
425 ops.ooblen = mtd->oobsize;
429 ops.mode = MTD_OPS_PLACE_OOB;
431 for (j = 0; j < numpages; j++) {
433 * Read the full oob until read_oob is fixed to handle single
434 * byte reads for 16 bit buswidth.
436 ret = mtd_read_oob(mtd, offs, &ops);
437 /* Ignore ECC errors when checking for BBM */
438 if (ret && !mtd_is_bitflip_or_eccerr(ret))
441 if (check_short_pattern(buf, bd))
444 offs += mtd->writesize;
450 * create_bbt - [GENERIC] Create a bad block table by scanning the device
451 * @mtd: MTD device structure
452 * @buf: temporary buffer
453 * @bd: descriptor for the good/bad block search pattern
454 * @chip: create the table for a specific chip, -1 read all chips; applies only
455 * if NAND_BBT_PERCHIP option is set
457 * Create a bad block table by scanning the device for the given good/bad block
460 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
461 struct nand_bbt_descr *bd, int chip)
463 struct nand_chip *this = mtd->priv;
464 int i, numblocks, numpages, scanlen;
469 pr_info("Scanning device for bad blocks\n");
471 if (bd->options & NAND_BBT_SCANALLPAGES)
472 numpages = 1 << (this->bbt_erase_shift - this->page_shift);
473 else if (bd->options & NAND_BBT_SCAN2NDPAGE)
478 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
479 /* We need only read few bytes from the OOB area */
483 /* Full page content should be read */
484 scanlen = mtd->writesize + mtd->oobsize;
485 readlen = numpages * mtd->writesize;
490 * Note that numblocks is 2 * (real numblocks) here, see i+=2
491 * below as it makes shifting and masking less painful
493 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
497 if (chip >= this->numchips) {
498 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
499 chip + 1, this->numchips);
502 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
503 startblock = chip * numblocks;
504 numblocks += startblock;
505 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
508 if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
509 from += mtd->erasesize - (mtd->writesize * numpages);
511 for (i = startblock; i < numblocks;) {
514 BUG_ON(bd->options & NAND_BBT_NO_OOB);
516 if (bd->options & NAND_BBT_SCANALLPAGES)
517 ret = scan_block_full(mtd, bd, from, buf, readlen,
520 ret = scan_block_fast(mtd, bd, from, buf, numpages);
526 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
527 pr_warn("Bad eraseblock %d at 0x%012llx\n",
528 i >> 1, (unsigned long long)from);
529 mtd->ecc_stats.badblocks++;
533 from += (1 << this->bbt_erase_shift);
539 * search_bbt - [GENERIC] scan the device for a specific bad block table
540 * @mtd: MTD device structure
541 * @buf: temporary buffer
542 * @td: descriptor for the bad block table
544 * Read the bad block table by searching for a given ident pattern. Search is
545 * preformed either from the beginning up or from the end of the device
546 * downwards. The search starts always at the start of a block. If the option
547 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
548 * the bad block information of this chip. This is necessary to provide support
549 * for certain DOC devices.
551 * The bbt ident pattern resides in the oob area of the first page in a block.
553 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
555 struct nand_chip *this = mtd->priv;
557 int startblock, block, dir;
558 int scanlen = mtd->writesize + mtd->oobsize;
560 int blocktopage = this->bbt_erase_shift - this->page_shift;
562 /* Search direction top -> down? */
563 if (td->options & NAND_BBT_LASTBLOCK) {
564 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
571 /* Do we have a bbt per chip? */
572 if (td->options & NAND_BBT_PERCHIP) {
573 chips = this->numchips;
574 bbtblocks = this->chipsize >> this->bbt_erase_shift;
575 startblock &= bbtblocks - 1;
578 bbtblocks = mtd->size >> this->bbt_erase_shift;
581 for (i = 0; i < chips; i++) {
582 /* Reset version information */
585 /* Scan the maximum number of blocks */
586 for (block = 0; block < td->maxblocks; block++) {
588 int actblock = startblock + dir * block;
589 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
591 /* Read first page */
592 scan_read(mtd, buf, offs, mtd->writesize, td);
593 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
594 td->pages[i] = actblock << blocktopage;
595 if (td->options & NAND_BBT_VERSION) {
596 offs = bbt_get_ver_offs(mtd, td);
597 td->version[i] = buf[offs];
602 startblock += this->chipsize >> this->bbt_erase_shift;
604 /* Check, if we found a bbt for each requested chip */
605 for (i = 0; i < chips; i++) {
606 if (td->pages[i] == -1)
607 pr_warn("Bad block table not found for chip %d\n", i);
609 pr_info("Bad block table found at page %d, version 0x%02X\n", td->pages[i],
616 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
617 * @mtd: MTD device structure
618 * @buf: temporary buffer
619 * @td: descriptor for the bad block table
620 * @md: descriptor for the bad block table mirror
622 * Search and read the bad block table(s).
624 static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf,
625 struct nand_bbt_descr *td,
626 struct nand_bbt_descr *md)
628 /* Search the primary table */
629 search_bbt(mtd, buf, td);
631 /* Search the mirror table */
633 search_bbt(mtd, buf, md);
637 * write_bbt - [GENERIC] (Re)write the bad block table
638 * @mtd: MTD device structure
639 * @buf: temporary buffer
640 * @td: descriptor for the bad block table
641 * @md: descriptor for the bad block table mirror
642 * @chipsel: selector for a specific chip, -1 for all
644 * (Re)write the bad block table.
646 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
647 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
650 struct nand_chip *this = mtd->priv;
651 struct erase_info einfo;
652 int i, j, res, chip = 0;
653 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
654 int nrchips, bbtoffs, pageoffs, ooboffs;
656 uint8_t rcode = td->reserved_block_code;
657 size_t retlen, len = 0;
659 struct mtd_oob_ops ops;
661 ops.ooblen = mtd->oobsize;
664 ops.mode = MTD_OPS_PLACE_OOB;
668 /* Write bad block table per chip rather than per device? */
669 if (td->options & NAND_BBT_PERCHIP) {
670 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
671 /* Full device write or specific chip? */
673 nrchips = this->numchips;
675 nrchips = chipsel + 1;
679 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
683 /* Loop through the chips */
684 for (; chip < nrchips; chip++) {
686 * There was already a version of the table, reuse the page
687 * This applies for absolute placement too, as we have the
688 * page nr. in td->pages.
690 if (td->pages[chip] != -1) {
691 page = td->pages[chip];
696 * Automatic placement of the bad block table. Search direction
699 if (td->options & NAND_BBT_LASTBLOCK) {
700 startblock = numblocks * (chip + 1) - 1;
703 startblock = chip * numblocks;
707 for (i = 0; i < td->maxblocks; i++) {
708 int block = startblock + dir * i;
709 /* Check, if the block is bad */
710 switch ((this->bbt[block >> 2] >>
711 (2 * (block & 0x03))) & 0x03) {
717 (this->bbt_erase_shift - this->page_shift);
718 /* Check, if the block is used by the mirror table */
719 if (!md || md->pages[chip] != page)
722 pr_err("No space left to write bad block table\n");
726 /* Set up shift count and masks for the flash table */
727 bits = td->options & NAND_BBT_NRBITS_MSK;
730 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
733 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
736 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
739 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
742 default: return -EINVAL;
745 bbtoffs = chip * (numblocks >> 2);
747 to = ((loff_t)page) << this->page_shift;
749 /* Must we save the block contents? */
750 if (td->options & NAND_BBT_SAVECONTENT) {
751 /* Make it block aligned */
752 to &= ~((loff_t)((1 << this->bbt_erase_shift) - 1));
753 len = 1 << this->bbt_erase_shift;
754 res = mtd_read(mtd, to, len, &retlen, buf);
757 pr_info("nand_bbt: error reading block "
758 "for writing the bad block table\n");
761 pr_warn("nand_bbt: ECC error while reading "
762 "block for writing bad block table\n");
765 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
766 ops.oobbuf = &buf[len];
767 res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
768 if (res < 0 || ops.oobretlen != ops.ooblen)
771 /* Calc the byte offset in the buffer */
772 pageoffs = page - (int)(to >> this->page_shift);
773 offs = pageoffs << this->page_shift;
774 /* Preset the bbt area with 0xff */
775 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
776 ooboffs = len + (pageoffs * mtd->oobsize);
778 } else if (td->options & NAND_BBT_NO_OOB) {
781 /* The version byte */
782 if (td->options & NAND_BBT_VERSION)
785 len = (size_t)(numblocks >> sft);
787 /* Make it page aligned! */
788 len = ALIGN(len, mtd->writesize);
789 /* Preset the buffer with 0xff */
790 memset(buf, 0xff, len);
791 /* Pattern is located at the begin of first page */
792 memcpy(buf, td->pattern, td->len);
795 len = (size_t)(numblocks >> sft);
796 /* Make it page aligned! */
797 len = ALIGN(len, mtd->writesize);
798 /* Preset the buffer with 0xff */
799 memset(buf, 0xff, len +
800 (len >> this->page_shift)* mtd->oobsize);
803 /* Pattern is located in oob area of first page */
804 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
807 if (td->options & NAND_BBT_VERSION)
808 buf[ooboffs + td->veroffs] = td->version[chip];
810 /* Walk through the memory table */
811 for (i = 0; i < numblocks;) {
813 dat = this->bbt[bbtoffs + (i >> 2)];
814 for (j = 0; j < 4; j++, i++) {
815 int sftcnt = (i << (3 - sft)) & sftmsk;
816 /* Do not store the reserved bbt blocks! */
817 buf[offs + (i >> sft)] &=
818 ~(msk[dat & 0x03] << sftcnt);
823 memset(&einfo, 0, sizeof(einfo));
826 einfo.len = 1 << this->bbt_erase_shift;
827 res = nand_erase_nand(mtd, &einfo, 1);
831 res = scan_write_bbt(mtd, to, len, buf,
832 td->options & NAND_BBT_NO_OOB ? NULL :
837 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
838 (unsigned long long)to, td->version[chip]);
840 /* Mark it as used */
841 td->pages[chip] = page;
846 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
851 * nand_memory_bbt - [GENERIC] create a memory based bad block table
852 * @mtd: MTD device structure
853 * @bd: descriptor for the good/bad block search pattern
855 * The function creates a memory based bbt by scanning the device for
856 * manufacturer / software marked good / bad blocks.
858 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
860 struct nand_chip *this = mtd->priv;
862 bd->options &= ~NAND_BBT_SCANEMPTY;
863 return create_bbt(mtd, this->buffers->databuf, bd, -1);
867 * check_create - [GENERIC] create and write bbt(s) if necessary
868 * @mtd: MTD device structure
869 * @buf: temporary buffer
870 * @bd: descriptor for the good/bad block search pattern
872 * The function checks the results of the previous call to read_bbt and creates
873 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
874 * for the chip/device. Update is necessary if one of the tables is missing or
875 * the version nr. of one table is less than the other.
877 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
879 int i, chips, writeops, create, chipsel, res, res2;
880 struct nand_chip *this = mtd->priv;
881 struct nand_bbt_descr *td = this->bbt_td;
882 struct nand_bbt_descr *md = this->bbt_md;
883 struct nand_bbt_descr *rd, *rd2;
885 /* Do we have a bbt per chip? */
886 if (td->options & NAND_BBT_PERCHIP)
887 chips = this->numchips;
891 for (i = 0; i < chips; i++) {
897 /* Per chip or per device? */
898 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
899 /* Mirrored table available? */
901 if (td->pages[i] == -1 && md->pages[i] == -1) {
904 } else if (td->pages[i] == -1) {
907 } else if (md->pages[i] == -1) {
910 } else if (td->version[i] == md->version[i]) {
912 if (!(td->options & NAND_BBT_VERSION))
914 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
922 if (td->pages[i] == -1) {
931 /* Create the bad block table by scanning the device? */
932 if (!(td->options & NAND_BBT_CREATE))
935 /* Create the table in memory by scanning the chip(s) */
936 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
937 create_bbt(mtd, buf, bd, chipsel);
944 /* Read back first? */
946 res = read_abs_bbt(mtd, buf, rd, chipsel);
947 if (mtd_is_eccerr(res)) {
948 /* Mark table as invalid */
955 /* If they weren't versioned, read both */
957 res2 = read_abs_bbt(mtd, buf, rd2, chipsel);
958 if (mtd_is_eccerr(res2)) {
959 /* Mark table as invalid */
967 /* Scrub the flash table(s)? */
968 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
971 /* Update version numbers before writing */
973 td->version[i] = max(td->version[i], md->version[i]);
974 md->version[i] = td->version[i];
977 /* Write the bad block table to the device? */
978 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
979 res = write_bbt(mtd, buf, td, md, chipsel);
984 /* Write the mirror bad block table to the device? */
985 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
986 res = write_bbt(mtd, buf, md, td, chipsel);
995 * mark_bbt_regions - [GENERIC] mark the bad block table regions
996 * @mtd: MTD device structure
997 * @td: bad block table descriptor
999 * The bad block table regions are marked as "bad" to prevent accidental
1000 * erasures / writes. The regions are identified by the mark 0x02.
1002 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
1004 struct nand_chip *this = mtd->priv;
1005 int i, j, chips, block, nrblocks, update;
1006 uint8_t oldval, newval;
1008 /* Do we have a bbt per chip? */
1009 if (td->options & NAND_BBT_PERCHIP) {
1010 chips = this->numchips;
1011 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
1014 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1017 for (i = 0; i < chips; i++) {
1018 if ((td->options & NAND_BBT_ABSPAGE) ||
1019 !(td->options & NAND_BBT_WRITE)) {
1020 if (td->pages[i] == -1)
1022 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1024 oldval = this->bbt[(block >> 3)];
1025 newval = oldval | (0x2 << (block & 0x06));
1026 this->bbt[(block >> 3)] = newval;
1027 if ((oldval != newval) && td->reserved_block_code)
1028 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
1032 if (td->options & NAND_BBT_LASTBLOCK)
1033 block = ((i + 1) * nrblocks) - td->maxblocks;
1035 block = i * nrblocks;
1037 for (j = 0; j < td->maxblocks; j++) {
1038 oldval = this->bbt[(block >> 3)];
1039 newval = oldval | (0x2 << (block & 0x06));
1040 this->bbt[(block >> 3)] = newval;
1041 if (oldval != newval)
1046 * If we want reserved blocks to be recorded to flash, and some
1047 * new ones have been marked, then we need to update the stored
1048 * bbts. This should only happen once.
1050 if (update && td->reserved_block_code)
1051 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
1056 * verify_bbt_descr - verify the bad block description
1057 * @mtd: MTD device structure
1058 * @bd: the table to verify
1060 * This functions performs a few sanity checks on the bad block description
1063 static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1065 struct nand_chip *this = mtd->priv;
1073 pattern_len = bd->len;
1074 bits = bd->options & NAND_BBT_NRBITS_MSK;
1076 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1077 !(this->bbt_options & NAND_BBT_USE_FLASH));
1080 if (bd->options & NAND_BBT_VERSION)
1083 if (bd->options & NAND_BBT_NO_OOB) {
1084 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1085 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1087 if (bd->options & NAND_BBT_VERSION)
1088 BUG_ON(bd->veroffs != bd->len);
1089 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1092 if (bd->options & NAND_BBT_PERCHIP)
1093 table_size = this->chipsize >> this->bbt_erase_shift;
1095 table_size = mtd->size >> this->bbt_erase_shift;
1098 if (bd->options & NAND_BBT_NO_OOB)
1099 table_size += pattern_len;
1100 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1104 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1105 * @mtd: MTD device structure
1106 * @bd: descriptor for the good/bad block search pattern
1108 * The function checks, if a bad block table(s) is/are already available. If
1109 * not it scans the device for manufacturer marked good / bad blocks and writes
1110 * the bad block table(s) to the selected place.
1112 * The bad block table memory is allocated here. It must be freed by calling
1113 * the nand_free_bbt function.
1115 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1117 struct nand_chip *this = mtd->priv;
1120 struct nand_bbt_descr *td = this->bbt_td;
1121 struct nand_bbt_descr *md = this->bbt_md;
1123 len = mtd->size >> (this->bbt_erase_shift + 2);
1125 * Allocate memory (2bit per block) and clear the memory bad block
1128 this->bbt = kzalloc(len, GFP_KERNEL);
1133 * If no primary table decriptor is given, scan the device to build a
1134 * memory based bad block table.
1137 if ((res = nand_memory_bbt(mtd, bd))) {
1138 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1144 verify_bbt_descr(mtd, td);
1145 verify_bbt_descr(mtd, md);
1147 /* Allocate a temporary buffer for one eraseblock incl. oob */
1148 len = (1 << this->bbt_erase_shift);
1149 len += (len >> this->page_shift) * mtd->oobsize;
1157 /* Is the bbt at a given page? */
1158 if (td->options & NAND_BBT_ABSPAGE) {
1159 read_abs_bbts(mtd, buf, td, md);
1161 /* Search the bad block table using a pattern in oob */
1162 search_read_bbts(mtd, buf, td, md);
1165 res = check_create(mtd, buf, bd);
1167 /* Prevent the bbt regions from erasing / writing */
1168 mark_bbt_region(mtd, td);
1170 mark_bbt_region(mtd, md);
1177 * nand_update_bbt - [NAND Interface] update bad block table(s)
1178 * @mtd: MTD device structure
1179 * @offs: the offset of the newly marked block
1181 * The function updates the bad block table(s).
1183 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1185 struct nand_chip *this = mtd->priv;
1189 struct nand_bbt_descr *td = this->bbt_td;
1190 struct nand_bbt_descr *md = this->bbt_md;
1192 if (!this->bbt || !td)
1195 /* Allocate a temporary buffer for one eraseblock incl. oob */
1196 len = (1 << this->bbt_erase_shift);
1197 len += (len >> this->page_shift) * mtd->oobsize;
1198 buf = kmalloc(len, GFP_KERNEL);
1202 /* Do we have a bbt per chip? */
1203 if (td->options & NAND_BBT_PERCHIP) {
1204 chip = (int)(offs >> this->chip_shift);
1211 td->version[chip]++;
1213 md->version[chip]++;
1215 /* Write the bad block table to the device? */
1216 if (td->options & NAND_BBT_WRITE) {
1217 res = write_bbt(mtd, buf, td, md, chipsel);
1221 /* Write the mirror bad block table to the device? */
1222 if (md && (md->options & NAND_BBT_WRITE)) {
1223 res = write_bbt(mtd, buf, md, td, chipsel);
1232 * Define some generic bad / good block scan pattern which are used
1233 * while scanning a device for factory marked good / bad blocks.
1235 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1237 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1239 static struct nand_bbt_descr agand_flashbased = {
1240 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1243 .pattern = scan_agand_pattern
1246 /* Generic flash bbt descriptors */
1247 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1248 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1250 static struct nand_bbt_descr bbt_main_descr = {
1251 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1252 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1256 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1257 .pattern = bbt_pattern
1260 static struct nand_bbt_descr bbt_mirror_descr = {
1261 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1262 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1266 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1267 .pattern = mirror_pattern
1270 static struct nand_bbt_descr bbt_main_no_oob_descr = {
1271 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1272 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1276 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1277 .pattern = bbt_pattern
1280 static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1281 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1282 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1286 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1287 .pattern = mirror_pattern
1290 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1292 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1293 * @this: NAND chip to create descriptor for
1295 * This function allocates and initializes a nand_bbt_descr for BBM detection
1296 * based on the properties of @this. The new descriptor is stored in
1297 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1298 * passed to this function.
1300 static int nand_create_badblock_pattern(struct nand_chip *this)
1302 struct nand_bbt_descr *bd;
1303 if (this->badblock_pattern) {
1304 pr_warn("Bad block pattern already allocated; not replacing\n");
1307 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1310 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1311 bd->offs = this->badblockpos;
1312 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1313 bd->pattern = scan_ff_pattern;
1314 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1315 this->badblock_pattern = bd;
1320 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1321 * @mtd: MTD device structure
1323 * This function selects the default bad block table support for the device and
1324 * calls the nand_scan_bbt function.
1326 int nand_default_bbt(struct mtd_info *mtd)
1328 struct nand_chip *this = mtd->priv;
1331 * Default for AG-AND. We must use a flash based bad block table as the
1332 * devices have factory marked _good_ blocks. Erasing those blocks
1333 * leads to loss of the good / bad information, so we _must_ store this
1334 * information in a good / bad table during startup.
1336 if (this->options & NAND_IS_AND) {
1337 /* Use the default pattern descriptors */
1338 if (!this->bbt_td) {
1339 this->bbt_td = &bbt_main_descr;
1340 this->bbt_md = &bbt_mirror_descr;
1342 this->bbt_options |= NAND_BBT_USE_FLASH;
1343 return nand_scan_bbt(mtd, &agand_flashbased);
1346 /* Is a flash based bad block table requested? */
1347 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1348 /* Use the default pattern descriptors */
1349 if (!this->bbt_td) {
1350 if (this->bbt_options & NAND_BBT_NO_OOB) {
1351 this->bbt_td = &bbt_main_no_oob_descr;
1352 this->bbt_md = &bbt_mirror_no_oob_descr;
1354 this->bbt_td = &bbt_main_descr;
1355 this->bbt_md = &bbt_mirror_descr;
1359 this->bbt_td = NULL;
1360 this->bbt_md = NULL;
1363 if (!this->badblock_pattern)
1364 nand_create_badblock_pattern(this);
1366 return nand_scan_bbt(mtd, this->badblock_pattern);
1370 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1371 * @mtd: MTD device structure
1372 * @offs: offset in the device
1373 * @allowbbt: allow access to bad block table region
1375 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1377 struct nand_chip *this = mtd->priv;
1381 /* Get block number * 2 */
1382 block = (int)(offs >> (this->bbt_erase_shift - 1));
1383 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1385 MTDDEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1386 (unsigned int)offs, block >> 1, res);
1394 return allowbbt ? 0 : 1;