2 * drivers/mtd/nand_bbt.c
5 * Bad block table support for the NAND driver
7 * Copyright (C) 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_USE_FLASH_BBT) 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 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27 * If one of the BBTs is out of date or does not exist it is (re)created.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.
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_USE_FLASH_BBT_NO_OOB should be used: it moves the ident pattern
40 * and the version byte into the data area and the OOB area will remain
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/nand.h>
67 #include <linux/mtd/nand_ecc.h>
68 #include <linux/bitops.h>
70 #include <asm/errno.h>
72 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
76 ret = memcmp(buf, td->pattern, td->len);
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
89 * Check for a pattern at the given place. Used to search bad block
90 * tables and good / bad block identifiers.
91 * If the SCAN_EMPTY option is set then check, if all bytes except the
92 * pattern area contain 0xff
95 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
100 if (td->options & NAND_BBT_NO_OOB)
101 return check_pattern_no_oob(buf, td);
103 end = paglen + td->offs;
104 if (td->options & NAND_BBT_SCANEMPTY) {
105 for (i = 0; i < end; i++) {
112 /* Compare the pattern */
113 for (i = 0; i < td->len; i++) {
114 if (p[i] != td->pattern[i])
118 /* Check both positions 1 and 6 for pattern? */
119 if (td->options & NAND_BBT_SCANBYTE1AND6) {
120 if (td->options & NAND_BBT_SCANEMPTY) {
122 end += NAND_SMALL_BADBLOCK_POS - td->offs;
123 /* Check region between positions 1 and 6 */
124 for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
131 p += NAND_SMALL_BADBLOCK_POS - td->offs;
133 /* Compare the pattern */
134 for (i = 0; i < td->len; i++) {
135 if (p[i] != td->pattern[i])
140 if (td->options & NAND_BBT_SCANEMPTY) {
143 for (i = end; i < len; i++) {
152 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
153 * @buf: the buffer to search
154 * @td: search pattern descriptor
156 * Check for a pattern at the given place. Used to search bad block
157 * tables and good / bad block identifiers. Same as check_pattern, but
158 * no optional empty check
161 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
166 /* Compare the pattern */
167 for (i = 0; i < td->len; i++) {
168 if (p[td->offs + i] != td->pattern[i])
171 /* Need to check location 1 AND 6? */
172 if (td->options & NAND_BBT_SCANBYTE1AND6) {
173 for (i = 0; i < td->len; i++) {
174 if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
182 * add_marker_len - compute the length of the marker in data area
183 * @td: BBT descriptor used for computation
185 * The length will be 0 if the markeris located in OOB area.
187 static u32 add_marker_len(struct nand_bbt_descr *td)
191 if (!(td->options & NAND_BBT_NO_OOB))
195 if (td->options & NAND_BBT_VERSION)
201 * read_bbt - [GENERIC] Read the bad block table starting from page
202 * @mtd: MTD device structure
203 * @buf: temporary buffer
204 * @page: the starting page
205 * @num: the number of bbt descriptors to read
206 * @td: the bbt describtion table
207 * @offs: offset in the memory table
209 * Read the bad block table starting from page.
212 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
213 struct nand_bbt_descr *td, int offs)
215 int res, i, j, act = 0;
216 struct nand_chip *this = mtd->priv;
217 size_t retlen, len, totlen;
219 int bits = td->options & NAND_BBT_NRBITS_MSK;
220 uint8_t msk = (uint8_t) ((1 << bits) - 1);
222 int reserved_block_code = td->reserved_block_code;
224 totlen = (num * bits) >> 3;
225 marker_len = add_marker_len(td);
226 from = ((loff_t) page) << this->page_shift;
229 len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
232 * In case the BBT marker is not in the OOB area it
233 * will be just in the first page.
239 res = mtd->read(mtd, from, len, &retlen, buf);
242 printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
245 printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
249 for (i = 0; i < len; i++) {
250 uint8_t dat = buf[i];
251 for (j = 0; j < 8; j += bits, act += 2) {
252 uint8_t tmp = (dat >> j) & msk;
255 if (reserved_block_code && (tmp == reserved_block_code)) {
256 printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n",
257 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
258 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
259 mtd->ecc_stats.bbtblocks++;
262 MTDDEBUG(MTD_DEBUG_LEVEL0, "nand_read_bbt: Bad block at 0x%012llx\n",
263 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
264 /* Factory marked bad or worn out ? */
266 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
268 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
269 mtd->ecc_stats.badblocks++;
279 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
280 * @mtd: MTD device structure
281 * @buf: temporary buffer
282 * @td: descriptor for the bad block table
283 * @chip: read the table for a specific chip, -1 read all chips.
284 * Applies only if NAND_BBT_PERCHIP option is set
286 * Read the bad block table for all chips starting at a given page
287 * We assume that the bbt bits are in consecutive order.
289 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
291 struct nand_chip *this = mtd->priv;
294 if (td->options & NAND_BBT_PERCHIP) {
296 for (i = 0; i < this->numchips; i++) {
297 if (chip == -1 || chip == i)
298 res = read_bbt(mtd, buf, td->pages[i],
299 this->chipsize >> this->bbt_erase_shift,
303 offs += this->chipsize >> (this->bbt_erase_shift + 2);
306 res = read_bbt(mtd, buf, td->pages[0],
307 mtd->size >> this->bbt_erase_shift, td, 0);
315 * BBT marker is in the first page, no OOB.
317 static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
318 struct nand_bbt_descr *td)
324 if (td->options & NAND_BBT_VERSION)
327 return mtd->read(mtd, offs, len, &retlen, buf);
331 * Scan read raw data from flash
333 static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
336 struct mtd_oob_ops ops;
339 ops.mode = MTD_OOB_RAW;
341 ops.ooblen = mtd->oobsize;
345 if (len <= mtd->writesize) {
346 ops.oobbuf = buf + len;
349 return mtd->read_oob(mtd, offs, &ops);
351 ops.oobbuf = buf + mtd->writesize;
353 ops.len = mtd->writesize;
354 res = mtd->read_oob(mtd, offs, &ops);
360 buf += mtd->oobsize + mtd->writesize;
361 len -= mtd->writesize;
366 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
367 size_t len, struct nand_bbt_descr *td)
369 if (td->options & NAND_BBT_NO_OOB)
370 return scan_read_raw_data(mtd, buf, offs, td);
372 return scan_read_raw_oob(mtd, buf, offs, len);
376 * Scan write data with oob to flash
378 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
379 uint8_t *buf, uint8_t *oob)
381 struct mtd_oob_ops ops;
383 ops.mode = MTD_OOB_PLACE;
385 ops.ooblen = mtd->oobsize;
390 return mtd->write_oob(mtd, offs, &ops);
393 static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
395 u32 ver_offs = td->veroffs;
397 if (!(td->options & NAND_BBT_NO_OOB))
398 ver_offs += mtd->writesize;
403 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
404 * @mtd: MTD device structure
405 * @buf: temporary buffer
406 * @td: descriptor for the bad block table
407 * @md: descriptor for the bad block table mirror
409 * Read the bad block table(s) for all chips starting at a given page
410 * We assume that the bbt bits are in consecutive order.
413 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
414 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
416 struct nand_chip *this = mtd->priv;
418 /* Read the primary version, if available */
419 if (td->options & NAND_BBT_VERSION) {
420 scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
422 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
423 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
424 td->pages[0], td->version[0]);
427 /* Read the mirror version, if available */
428 if (md && (md->options & NAND_BBT_VERSION)) {
429 scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
431 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
432 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
433 md->pages[0], md->version[0]);
439 * Scan a given block full
441 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
442 loff_t offs, uint8_t *buf, size_t readlen,
443 int scanlen, int len)
447 ret = scan_read_raw_oob(mtd, buf, offs, readlen);
451 for (j = 0; j < len; j++, buf += scanlen) {
452 if (check_pattern(buf, scanlen, mtd->writesize, bd))
459 * Scan a given block partially
461 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
462 loff_t offs, uint8_t *buf, int len)
464 struct mtd_oob_ops ops;
467 ops.ooblen = mtd->oobsize;
471 ops.mode = MTD_OOB_PLACE;
473 for (j = 0; j < len; j++) {
475 * Read the full oob until read_oob is fixed to
476 * handle single byte reads for 16 bit
479 ret = mtd->read_oob(mtd, offs, &ops);
483 if (check_short_pattern(buf, bd))
486 offs += mtd->writesize;
492 * create_bbt - [GENERIC] Create a bad block table by scanning the device
493 * @mtd: MTD device structure
494 * @buf: temporary buffer
495 * @bd: descriptor for the good/bad block search pattern
496 * @chip: create the table for a specific chip, -1 read all chips.
497 * Applies only if NAND_BBT_PERCHIP option is set
499 * Create a bad block table by scanning the device
500 * for the given good/bad block identify pattern
502 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
503 struct nand_bbt_descr *bd, int chip)
505 struct nand_chip *this = mtd->priv;
506 int i, numblocks, len, scanlen;
511 MTDDEBUG(MTD_DEBUG_LEVEL0, "Scanning device for bad blocks\n");
513 if (bd->options & NAND_BBT_SCANALLPAGES)
514 len = 1 << (this->bbt_erase_shift - this->page_shift);
515 else if (bd->options & NAND_BBT_SCAN2NDPAGE)
520 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
521 /* We need only read few bytes from the OOB area */
525 /* Full page content should be read */
526 scanlen = mtd->writesize + mtd->oobsize;
527 readlen = len * mtd->writesize;
531 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
532 * below as it makes shifting and masking less painful */
533 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
537 if (chip >= this->numchips) {
538 printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
539 chip + 1, this->numchips);
542 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
543 startblock = chip * numblocks;
544 numblocks += startblock;
545 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
548 if (this->options & NAND_BBT_SCANLASTPAGE)
549 from += mtd->erasesize - (mtd->writesize * len);
551 for (i = startblock; i < numblocks;) {
554 BUG_ON(bd->options & NAND_BBT_NO_OOB);
556 if (bd->options & NAND_BBT_SCANALLPAGES)
557 ret = scan_block_full(mtd, bd, from, buf, readlen,
560 ret = scan_block_fast(mtd, bd, from, buf, len);
566 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
567 MTDDEBUG(MTD_DEBUG_LEVEL0,
568 "Bad eraseblock %d at 0x%012llx\n",
569 i >> 1, (unsigned long long)from);
570 mtd->ecc_stats.badblocks++;
574 from += (1 << this->bbt_erase_shift);
580 * search_bbt - [GENERIC] scan the device for a specific bad block table
581 * @mtd: MTD device structure
582 * @buf: temporary buffer
583 * @td: descriptor for the bad block table
585 * Read the bad block table by searching for a given ident pattern.
586 * Search is preformed either from the beginning up or from the end of
587 * the device downwards. The search starts always at the start of a
589 * If the option NAND_BBT_PERCHIP is given, each chip is searched
590 * for a bbt, which contains the bad block information of this chip.
591 * This is necessary to provide support for certain DOC devices.
593 * The bbt ident pattern resides in the oob area of the first page
596 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
598 struct nand_chip *this = mtd->priv;
600 int startblock, block, dir;
601 int scanlen = mtd->writesize + mtd->oobsize;
603 int blocktopage = this->bbt_erase_shift - this->page_shift;
605 /* Search direction top -> down ? */
606 if (td->options & NAND_BBT_LASTBLOCK) {
607 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
614 /* Do we have a bbt per chip ? */
615 if (td->options & NAND_BBT_PERCHIP) {
616 chips = this->numchips;
617 bbtblocks = this->chipsize >> this->bbt_erase_shift;
618 startblock &= bbtblocks - 1;
621 bbtblocks = mtd->size >> this->bbt_erase_shift;
624 for (i = 0; i < chips; i++) {
625 /* Reset version information */
628 /* Scan the maximum number of blocks */
629 for (block = 0; block < td->maxblocks; block++) {
631 int actblock = startblock + dir * block;
632 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
634 /* Read first page */
635 scan_read_raw(mtd, buf, offs, mtd->writesize, td);
636 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
637 td->pages[i] = actblock << blocktopage;
638 if (td->options & NAND_BBT_VERSION) {
639 offs = bbt_get_ver_offs(mtd, td);
640 td->version[i] = buf[offs];
645 startblock += this->chipsize >> this->bbt_erase_shift;
647 /* Check, if we found a bbt for each requested chip */
648 for (i = 0; i < chips; i++) {
649 if (td->pages[i] == -1)
650 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
652 MTDDEBUG(MTD_DEBUG_LEVEL0,
653 "Bad block table found at page %d, version 0x%02X\n",
654 td->pages[i], td->version[i]);
660 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
661 * @mtd: MTD device structure
662 * @buf: temporary buffer
663 * @td: descriptor for the bad block table
664 * @md: descriptor for the bad block table mirror
666 * Search and read the bad block table(s)
668 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
670 /* Search the primary table */
671 search_bbt(mtd, buf, td);
673 /* Search the mirror table */
675 search_bbt(mtd, buf, md);
677 /* Force result check */
682 * write_bbt - [GENERIC] (Re)write the bad block table
684 * @mtd: MTD device structure
685 * @buf: temporary buffer
686 * @td: descriptor for the bad block table
687 * @md: descriptor for the bad block table mirror
688 * @chipsel: selector for a specific chip, -1 for all
690 * (Re)write the bad block table
693 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
694 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
697 struct nand_chip *this = mtd->priv;
698 struct erase_info einfo;
699 int i, j, res, chip = 0;
700 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
701 int nrchips, bbtoffs, pageoffs, ooboffs;
703 uint8_t rcode = td->reserved_block_code;
704 size_t retlen, len = 0;
706 struct mtd_oob_ops ops;
708 ops.ooblen = mtd->oobsize;
711 ops.mode = MTD_OOB_PLACE;
715 /* Write bad block table per chip rather than per device ? */
716 if (td->options & NAND_BBT_PERCHIP) {
717 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
718 /* Full device write or specific chip ? */
720 nrchips = this->numchips;
722 nrchips = chipsel + 1;
726 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
730 /* Loop through the chips */
731 for (; chip < nrchips; chip++) {
733 /* There was already a version of the table, reuse the page
734 * This applies for absolute placement too, as we have the
735 * page nr. in td->pages.
737 if (td->pages[chip] != -1) {
738 page = td->pages[chip];
742 /* Automatic placement of the bad block table */
743 /* Search direction top -> down ? */
744 if (td->options & NAND_BBT_LASTBLOCK) {
745 startblock = numblocks * (chip + 1) - 1;
748 startblock = chip * numblocks;
752 for (i = 0; i < td->maxblocks; i++) {
753 int block = startblock + dir * i;
754 /* Check, if the block is bad */
755 switch ((this->bbt[block >> 2] >>
756 (2 * (block & 0x03))) & 0x03) {
762 (this->bbt_erase_shift - this->page_shift);
763 /* Check, if the block is used by the mirror table */
764 if (!md || md->pages[chip] != page)
767 printk(KERN_ERR "No space left to write bad block table\n");
771 /* Set up shift count and masks for the flash table */
772 bits = td->options & NAND_BBT_NRBITS_MSK;
775 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
778 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
781 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
784 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
787 default: return -EINVAL;
790 bbtoffs = chip * (numblocks >> 2);
792 to = ((loff_t) page) << this->page_shift;
794 /* Must we save the block contents ? */
795 if (td->options & NAND_BBT_SAVECONTENT) {
796 /* Make it block aligned */
797 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
798 len = 1 << this->bbt_erase_shift;
799 res = mtd->read(mtd, to, len, &retlen, buf);
802 printk(KERN_INFO "nand_bbt: Error "
803 "reading block for writing "
804 "the bad block table\n");
807 printk(KERN_WARNING "nand_bbt: ECC error "
808 "while reading block for writing "
809 "bad block table\n");
812 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
813 ops.oobbuf = &buf[len];
814 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
815 if (res < 0 || ops.oobretlen != ops.ooblen)
818 /* Calc the byte offset in the buffer */
819 pageoffs = page - (int)(to >> this->page_shift);
820 offs = pageoffs << this->page_shift;
821 /* Preset the bbt area with 0xff */
822 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
823 ooboffs = len + (pageoffs * mtd->oobsize);
825 } else if (td->options & NAND_BBT_NO_OOB) {
828 /* the version byte */
829 if (td->options & NAND_BBT_VERSION)
832 len = (size_t) (numblocks >> sft);
834 /* Make it page aligned ! */
835 len = ALIGN(len, mtd->writesize);
836 /* Preset the buffer with 0xff */
837 memset(buf, 0xff, len);
838 /* Pattern is located at the begin of first page */
839 memcpy(buf, td->pattern, td->len);
842 len = (size_t) (numblocks >> sft);
843 /* Make it page aligned ! */
844 len = ALIGN(len, mtd->writesize);
845 /* Preset the buffer with 0xff */
846 memset(buf, 0xff, len +
847 (len >> this->page_shift)* mtd->oobsize);
850 /* Pattern is located in oob area of first page */
851 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
854 if (td->options & NAND_BBT_VERSION)
855 buf[ooboffs + td->veroffs] = td->version[chip];
857 /* walk through the memory table */
858 for (i = 0; i < numblocks;) {
860 dat = this->bbt[bbtoffs + (i >> 2)];
861 for (j = 0; j < 4; j++, i++) {
862 int sftcnt = (i << (3 - sft)) & sftmsk;
863 /* Do not store the reserved bbt blocks ! */
864 buf[offs + (i >> sft)] &=
865 ~(msk[dat & 0x03] << sftcnt);
870 memset(&einfo, 0, sizeof(einfo));
873 einfo.len = 1 << this->bbt_erase_shift;
874 res = nand_erase_nand(mtd, &einfo, 1);
878 res = scan_write_bbt(mtd, to, len, buf,
879 td->options & NAND_BBT_NO_OOB ? NULL :
884 printk(KERN_DEBUG "Bad block table written to 0x%012llx, version "
885 "0x%02X\n", (unsigned long long)to, td->version[chip]);
887 /* Mark it as used */
888 td->pages[chip] = page;
894 "nand_bbt: Error while writing bad block table %d\n", res);
899 * nand_memory_bbt - [GENERIC] create a memory based bad block table
900 * @mtd: MTD device structure
901 * @bd: descriptor for the good/bad block search pattern
903 * The function creates a memory based bbt by scanning the device
904 * for manufacturer / software marked good / bad blocks
906 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
908 struct nand_chip *this = mtd->priv;
910 bd->options &= ~NAND_BBT_SCANEMPTY;
911 return create_bbt(mtd, this->buffers->databuf, bd, -1);
915 * check_create - [GENERIC] create and write bbt(s) if necessary
916 * @mtd: MTD device structure
917 * @buf: temporary buffer
918 * @bd: descriptor for the good/bad block search pattern
920 * The function checks the results of the previous call to read_bbt
921 * and creates / updates the bbt(s) if necessary
922 * Creation is necessary if no bbt was found for the chip/device
923 * Update is necessary if one of the tables is missing or the
924 * version nr. of one table is less than the other
926 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
928 int i, chips, writeops, chipsel, res;
929 struct nand_chip *this = mtd->priv;
930 struct nand_bbt_descr *td = this->bbt_td;
931 struct nand_bbt_descr *md = this->bbt_md;
932 struct nand_bbt_descr *rd, *rd2;
934 /* Do we have a bbt per chip ? */
935 if (td->options & NAND_BBT_PERCHIP)
936 chips = this->numchips;
940 for (i = 0; i < chips; i++) {
944 /* Per chip or per device ? */
945 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
946 /* Mirrored table available ? */
948 if (td->pages[i] == -1 && md->pages[i] == -1) {
953 if (td->pages[i] == -1) {
955 td->version[i] = md->version[i];
960 if (md->pages[i] == -1) {
962 md->version[i] = td->version[i];
967 if (td->version[i] == md->version[i]) {
969 if (!(td->options & NAND_BBT_VERSION))
974 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
976 md->version[i] = td->version[i];
980 td->version[i] = md->version[i];
987 if (td->pages[i] == -1) {
995 /* Create the bad block table by scanning the device ? */
996 if (!(td->options & NAND_BBT_CREATE))
999 /* Create the table in memory by scanning the chip(s) */
1000 if (!(this->options & NAND_CREATE_EMPTY_BBT))
1001 create_bbt(mtd, buf, bd, chipsel);
1007 /* read back first ? */
1009 read_abs_bbt(mtd, buf, rd, chipsel);
1010 /* If they weren't versioned, read both. */
1012 read_abs_bbt(mtd, buf, rd2, chipsel);
1014 /* Write the bad block table to the device ? */
1015 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1016 res = write_bbt(mtd, buf, td, md, chipsel);
1021 /* Write the mirror bad block table to the device ? */
1022 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1023 res = write_bbt(mtd, buf, md, td, chipsel);
1032 * mark_bbt_regions - [GENERIC] mark the bad block table regions
1033 * @mtd: MTD device structure
1034 * @td: bad block table descriptor
1036 * The bad block table regions are marked as "bad" to prevent
1037 * accidental erasures / writes. The regions are identified by
1040 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
1042 struct nand_chip *this = mtd->priv;
1043 int i, j, chips, block, nrblocks, update;
1044 uint8_t oldval, newval;
1046 /* Do we have a bbt per chip ? */
1047 if (td->options & NAND_BBT_PERCHIP) {
1048 chips = this->numchips;
1049 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
1052 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1055 for (i = 0; i < chips; i++) {
1056 if ((td->options & NAND_BBT_ABSPAGE) ||
1057 !(td->options & NAND_BBT_WRITE)) {
1058 if (td->pages[i] == -1)
1060 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1062 oldval = this->bbt[(block >> 3)];
1063 newval = oldval | (0x2 << (block & 0x06));
1064 this->bbt[(block >> 3)] = newval;
1065 if ((oldval != newval) && td->reserved_block_code)
1066 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
1070 if (td->options & NAND_BBT_LASTBLOCK)
1071 block = ((i + 1) * nrblocks) - td->maxblocks;
1073 block = i * nrblocks;
1075 for (j = 0; j < td->maxblocks; j++) {
1076 oldval = this->bbt[(block >> 3)];
1077 newval = oldval | (0x2 << (block & 0x06));
1078 this->bbt[(block >> 3)] = newval;
1079 if (oldval != newval)
1083 /* If we want reserved blocks to be recorded to flash, and some
1084 new ones have been marked, then we need to update the stored
1085 bbts. This should only happen once. */
1086 if (update && td->reserved_block_code)
1087 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
1092 * verify_bbt_descr - verify the bad block description
1093 * @mtd: MTD device structure
1094 * @bd: the table to verify
1096 * This functions performs a few sanity checks on the bad block description
1099 static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1101 struct nand_chip *this = mtd->priv;
1109 pattern_len = bd->len;
1110 bits = bd->options & NAND_BBT_NRBITS_MSK;
1112 BUG_ON((this->options & NAND_USE_FLASH_BBT_NO_OOB) &&
1113 !(this->options & NAND_USE_FLASH_BBT));
1116 if (bd->options & NAND_BBT_VERSION)
1119 if (bd->options & NAND_BBT_NO_OOB) {
1120 BUG_ON(!(this->options & NAND_USE_FLASH_BBT));
1121 BUG_ON(!(this->options & NAND_USE_FLASH_BBT_NO_OOB));
1123 if (bd->options & NAND_BBT_VERSION)
1124 BUG_ON(bd->veroffs != bd->len);
1125 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1128 if (bd->options & NAND_BBT_PERCHIP)
1129 table_size = this->chipsize >> this->bbt_erase_shift;
1131 table_size = mtd->size >> this->bbt_erase_shift;
1134 if (bd->options & NAND_BBT_NO_OOB)
1135 table_size += pattern_len;
1136 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1140 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1141 * @mtd: MTD device structure
1142 * @bd: descriptor for the good/bad block search pattern
1144 * The function checks, if a bad block table(s) is/are already
1145 * available. If not it scans the device for manufacturer
1146 * marked good / bad blocks and writes the bad block table(s) to
1147 * the selected place.
1149 * The bad block table memory is allocated here. It must be freed
1150 * by calling the nand_free_bbt function.
1153 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1155 struct nand_chip *this = mtd->priv;
1158 struct nand_bbt_descr *td = this->bbt_td;
1159 struct nand_bbt_descr *md = this->bbt_md;
1161 len = mtd->size >> (this->bbt_erase_shift + 2);
1162 /* Allocate memory (2bit per block) and clear the memory bad block table */
1163 this->bbt = kzalloc(len, GFP_KERNEL);
1165 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
1169 /* If no primary table decriptor is given, scan the device
1170 * to build a memory based bad block table
1173 if ((res = nand_memory_bbt(mtd, bd))) {
1174 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1180 verify_bbt_descr(mtd, td);
1181 verify_bbt_descr(mtd, md);
1183 /* Allocate a temporary buffer for one eraseblock incl. oob */
1184 len = (1 << this->bbt_erase_shift);
1185 len += (len >> this->page_shift) * mtd->oobsize;
1188 printk(KERN_ERR "nand_bbt: Out of memory\n");
1194 /* Is the bbt at a given page ? */
1195 if (td->options & NAND_BBT_ABSPAGE) {
1196 res = read_abs_bbts(mtd, buf, td, md);
1198 /* Search the bad block table using a pattern in oob */
1199 res = search_read_bbts(mtd, buf, td, md);
1203 res = check_create(mtd, buf, bd);
1205 /* Prevent the bbt regions from erasing / writing */
1206 mark_bbt_region(mtd, td);
1208 mark_bbt_region(mtd, md);
1215 * nand_update_bbt - [NAND Interface] update bad block table(s)
1216 * @mtd: MTD device structure
1217 * @offs: the offset of the newly marked block
1219 * The function updates the bad block table(s)
1221 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1223 struct nand_chip *this = mtd->priv;
1224 int len, res = 0, writeops = 0;
1227 struct nand_bbt_descr *td = this->bbt_td;
1228 struct nand_bbt_descr *md = this->bbt_md;
1230 if (!this->bbt || !td)
1233 /* Allocate a temporary buffer for one eraseblock incl. oob */
1234 len = (1 << this->bbt_erase_shift);
1235 len += (len >> this->page_shift) * mtd->oobsize;
1236 buf = kmalloc(len, GFP_KERNEL);
1238 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1242 writeops = md != NULL ? 0x03 : 0x01;
1244 /* Do we have a bbt per chip ? */
1245 if (td->options & NAND_BBT_PERCHIP) {
1246 chip = (int)(offs >> this->chip_shift);
1253 td->version[chip]++;
1255 md->version[chip]++;
1257 /* Write the bad block table to the device ? */
1258 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1259 res = write_bbt(mtd, buf, td, md, chipsel);
1263 /* Write the mirror bad block table to the device ? */
1264 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1265 res = write_bbt(mtd, buf, md, td, chipsel);
1273 /* Define some generic bad / good block scan pattern which are used
1274 * while scanning a device for factory marked good / bad blocks. */
1275 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1277 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1279 static struct nand_bbt_descr agand_flashbased = {
1280 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1283 .pattern = scan_agand_pattern
1286 /* Generic flash bbt decriptors
1288 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1289 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1291 static struct nand_bbt_descr bbt_main_descr = {
1292 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1293 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1298 .pattern = bbt_pattern
1301 static struct nand_bbt_descr bbt_mirror_descr = {
1302 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1303 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1308 .pattern = mirror_pattern
1311 static struct nand_bbt_descr bbt_main_no_bbt_descr = {
1312 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1313 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1318 .pattern = bbt_pattern
1321 static struct nand_bbt_descr bbt_mirror_no_bbt_descr = {
1322 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1323 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1328 .pattern = mirror_pattern
1331 #define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
1332 NAND_BBT_SCANBYTE1AND6)
1334 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1335 * @this: NAND chip to create descriptor for
1337 * This function allocates and initializes a nand_bbt_descr for BBM detection
1338 * based on the properties of "this". The new descriptor is stored in
1339 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1340 * passed to this function.
1343 static int nand_create_default_bbt_descr(struct nand_chip *this)
1345 struct nand_bbt_descr *bd;
1346 if (this->badblock_pattern) {
1347 printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
1350 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1352 printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
1355 bd->options = this->options & BBT_SCAN_OPTIONS;
1356 bd->offs = this->badblockpos;
1357 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1358 bd->pattern = scan_ff_pattern;
1359 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1360 this->badblock_pattern = bd;
1365 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1366 * @mtd: MTD device structure
1368 * This function selects the default bad block table
1369 * support for the device and calls the nand_scan_bbt function
1372 int nand_default_bbt(struct mtd_info *mtd)
1374 struct nand_chip *this = mtd->priv;
1376 /* Default for AG-AND. We must use a flash based
1377 * bad block table as the devices have factory marked
1378 * _good_ blocks. Erasing those blocks leads to loss
1379 * of the good / bad information, so we _must_ store
1380 * this information in a good / bad table during
1383 if (this->options & NAND_IS_AND) {
1384 /* Use the default pattern descriptors */
1385 if (!this->bbt_td) {
1386 this->bbt_td = &bbt_main_descr;
1387 this->bbt_md = &bbt_mirror_descr;
1389 this->options |= NAND_USE_FLASH_BBT;
1390 return nand_scan_bbt(mtd, &agand_flashbased);
1393 /* Is a flash based bad block table requested ? */
1394 if (this->options & NAND_USE_FLASH_BBT) {
1395 /* Use the default pattern descriptors */
1396 if (!this->bbt_td) {
1397 if (this->options & NAND_USE_FLASH_BBT_NO_OOB) {
1398 this->bbt_td = &bbt_main_no_bbt_descr;
1399 this->bbt_md = &bbt_mirror_no_bbt_descr;
1401 this->bbt_td = &bbt_main_descr;
1402 this->bbt_md = &bbt_mirror_descr;
1406 this->bbt_td = NULL;
1407 this->bbt_md = NULL;
1410 if (!this->badblock_pattern)
1411 nand_create_default_bbt_descr(this);
1413 return nand_scan_bbt(mtd, this->badblock_pattern);
1417 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1418 * @mtd: MTD device structure
1419 * @offs: offset in the device
1420 * @allowbbt: allow access to bad block table region
1423 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1425 struct nand_chip *this = mtd->priv;
1429 /* Get block number * 2 */
1430 block = (int)(offs >> (this->bbt_erase_shift - 1));
1431 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1433 MTDDEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1434 (unsigned int)offs, block >> 1, res);
1442 return allowbbt ? 0 : 1;