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 a bbt is found
17 * then the contents are read and the memory based bbt is created. If a
18 * mirrored bbt is selected then the mirror is searched too and the
19 * versions are compared. If the mirror has a greater version number
20 * than the mirror bbt is used to build the memory based bbt.
21 * If the tables are not versioned, then we "or" the bad block information.
22 * If one of the bbt's is out of date or does not exist it is (re)created.
23 * If no bbt exists at all then the device is scanned for factory marked
24 * good / bad blocks and the bad block tables are created.
26 * For manufacturer created bbts like the one found on M-SYS DOC devices
27 * the bbt is searched and read but never created
29 * The autogenerated bad block table is located in the last good blocks
30 * of the device. The table is mirrored, so it can be updated eventually.
31 * The table is marked in the oob area with an ident pattern and a version
32 * number which indicates which of both tables is more up to date.
34 * The table uses 2 bits per block
36 * 00b: block is factory marked bad
37 * 01b, 10b: block is marked bad due to wear
39 * The memory bad block table uses the following scheme:
41 * 01b: block is marked bad due to wear
42 * 10b: block is reserved (to protect the bbt area)
43 * 11b: block is factory marked bad
45 * Multichip devices like DOC store the bad block info per floor.
47 * Following assumptions are made:
48 * - bbts start at a page boundary, if autolocated on a block boundary
49 * - the space necessary for a bbt in FLASH does not exceed a block boundary
55 #include <linux/mtd/compat.h>
56 #include <linux/mtd/mtd.h>
57 #include <linux/mtd/nand.h>
59 #include <asm/errno.h>
62 * check_pattern - [GENERIC] check if a pattern is in the buffer
63 * @buf: the buffer to search
64 * @len: the length of buffer to search
65 * @paglen: the pagelength
66 * @td: search pattern descriptor
68 * Check for a pattern at the given place. Used to search bad block
69 * tables and good / bad block identifiers.
70 * If the SCAN_EMPTY option is set then check, if all bytes except the
71 * pattern area contain 0xff
74 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
79 end = paglen + td->offs;
80 if (td->options & NAND_BBT_SCANEMPTY) {
81 for (i = 0; i < end; i++) {
88 /* Compare the pattern */
89 for (i = 0; i < td->len; i++) {
90 if (p[i] != td->pattern[i])
94 if (td->options & NAND_BBT_SCANEMPTY) {
97 for (i = end; i < len; i++) {
106 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
107 * @buf: the buffer to search
108 * @td: search pattern descriptor
110 * Check for a pattern at the given place. Used to search bad block
111 * tables and good / bad block identifiers. Same as check_pattern, but
112 * no optional empty check
115 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
120 /* Compare the pattern */
121 for (i = 0; i < td->len; i++) {
122 if (p[td->offs + i] != td->pattern[i])
129 * read_bbt - [GENERIC] Read the bad block table starting from page
130 * @mtd: MTD device structure
131 * @buf: temporary buffer
132 * @page: the starting page
133 * @num: the number of bbt descriptors to read
134 * @bits: number of bits per block
135 * @offs: offset in the memory table
136 * @reserved_block_code: Pattern to identify reserved blocks
138 * Read the bad block table starting from page.
141 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
142 int bits, int offs, int reserved_block_code)
144 int res, i, j, act = 0;
145 struct nand_chip *this = mtd->priv;
146 size_t retlen, len, totlen;
148 uint8_t msk = (uint8_t) ((1 << bits) - 1);
150 totlen = (num * bits) >> 3;
151 from = ((loff_t) page) << this->page_shift;
154 len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
155 res = mtd->read(mtd, from, len, &retlen, buf);
158 printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
161 printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
165 for (i = 0; i < len; i++) {
166 uint8_t dat = buf[i];
167 for (j = 0; j < 8; j += bits, act += 2) {
168 uint8_t tmp = (dat >> j) & msk;
171 if (reserved_block_code && (tmp == reserved_block_code)) {
172 printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n",
173 (loff_t)((offs << 2) +
175 this->bbt_erase_shift);
176 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
177 mtd->ecc_stats.bbtblocks++;
180 /* Leave it for now, if its matured we can move this
181 * message to MTD_DEBUG_LEVEL0 */
182 printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n",
183 (loff_t)((offs << 2) + (act >> 1)) <<
184 this->bbt_erase_shift);
185 /* Factory marked bad or worn out ? */
187 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
189 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
190 mtd->ecc_stats.badblocks++;
200 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
201 * @mtd: MTD device structure
202 * @buf: temporary buffer
203 * @td: descriptor for the bad block table
204 * @chip: read the table for a specific chip, -1 read all chips.
205 * Applies only if NAND_BBT_PERCHIP option is set
207 * Read the bad block table for all chips starting at a given page
208 * We assume that the bbt bits are in consecutive order.
210 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
212 struct nand_chip *this = mtd->priv;
216 bits = td->options & NAND_BBT_NRBITS_MSK;
217 if (td->options & NAND_BBT_PERCHIP) {
219 for (i = 0; i < this->numchips; i++) {
220 if (chip == -1 || chip == i)
221 res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
224 offs += this->chipsize >> (this->bbt_erase_shift + 2);
227 res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
235 * Scan read raw data from flash
237 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
240 struct mtd_oob_ops ops;
242 ops.mode = MTD_OOB_RAW;
244 ops.ooblen = mtd->oobsize;
249 return mtd->read_oob(mtd, offs, &ops);
253 * Scan write data with oob to flash
255 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
256 uint8_t *buf, uint8_t *oob)
258 struct mtd_oob_ops ops;
260 ops.mode = MTD_OOB_PLACE;
262 ops.ooblen = mtd->oobsize;
267 return mtd->write_oob(mtd, offs, &ops);
271 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
272 * @mtd: MTD device structure
273 * @buf: temporary buffer
274 * @td: descriptor for the bad block table
275 * @md: descriptor for the bad block table mirror
277 * Read the bad block table(s) for all chips starting at a given page
278 * We assume that the bbt bits are in consecutive order.
281 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
282 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
284 struct nand_chip *this = mtd->priv;
286 /* Read the primary version, if available */
287 if (td->options & NAND_BBT_VERSION) {
288 scan_read_raw(mtd, buf, (loff_t)td->pages[0] <<
289 this->page_shift, mtd->writesize);
290 td->version[0] = buf[mtd->writesize + td->veroffs];
291 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
292 td->pages[0], td->version[0]);
295 /* Read the mirror version, if available */
296 if (md && (md->options & NAND_BBT_VERSION)) {
297 scan_read_raw(mtd, buf, (loff_t)md->pages[0] <<
298 this->page_shift, mtd->writesize);
299 md->version[0] = buf[mtd->writesize + md->veroffs];
300 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
301 md->pages[0], md->version[0]);
307 * Scan a given block full
309 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
310 loff_t offs, uint8_t *buf, size_t readlen,
311 int scanlen, int len)
315 ret = scan_read_raw(mtd, buf, offs, readlen);
319 for (j = 0; j < len; j++, buf += scanlen) {
320 if (check_pattern(buf, scanlen, mtd->writesize, bd))
327 * Scan a given block partially
329 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
330 loff_t offs, uint8_t *buf, int len)
332 struct mtd_oob_ops ops;
335 ops.ooblen = mtd->oobsize;
339 ops.mode = MTD_OOB_PLACE;
341 for (j = 0; j < len; j++) {
343 * Read the full oob until read_oob is fixed to
344 * handle single byte reads for 16 bit
347 ret = mtd->read_oob(mtd, offs, &ops);
351 if (check_short_pattern(buf, bd))
354 offs += mtd->writesize;
360 * create_bbt - [GENERIC] Create a bad block table by scanning the device
361 * @mtd: MTD device structure
362 * @buf: temporary buffer
363 * @bd: descriptor for the good/bad block search pattern
364 * @chip: create the table for a specific chip, -1 read all chips.
365 * Applies only if NAND_BBT_PERCHIP option is set
367 * Create a bad block table by scanning the device
368 * for the given good/bad block identify pattern
370 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
371 struct nand_bbt_descr *bd, int chip)
373 struct nand_chip *this = mtd->priv;
374 int i, numblocks, len, scanlen;
379 MTDDEBUG (MTD_DEBUG_LEVEL0, "Scanning device for bad blocks\n");
381 if (bd->options & NAND_BBT_SCANALLPAGES)
382 len = 1 << (this->bbt_erase_shift - this->page_shift);
384 if (bd->options & NAND_BBT_SCAN2NDPAGE)
390 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
391 /* We need only read few bytes from the OOB area */
395 /* Full page content should be read */
396 scanlen = mtd->writesize + mtd->oobsize;
397 readlen = len * mtd->writesize;
401 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
402 * below as it makes shifting and masking less painful */
403 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
407 if (chip >= this->numchips) {
408 printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
409 chip + 1, this->numchips);
412 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
413 startblock = chip * numblocks;
414 numblocks += startblock;
415 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
418 for (i = startblock; i < numblocks;) {
421 if (bd->options & NAND_BBT_SCANALLPAGES)
422 ret = scan_block_full(mtd, bd, from, buf, readlen,
425 ret = scan_block_fast(mtd, bd, from, buf, len);
431 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
432 MTDDEBUG (MTD_DEBUG_LEVEL0,
433 "Bad eraseblock %d at 0x%012llx\n",
434 i >> 1, (unsigned long long)from);
435 mtd->ecc_stats.badblocks++;
439 from += (1 << this->bbt_erase_shift);
445 * search_bbt - [GENERIC] scan the device for a specific bad block table
446 * @mtd: MTD device structure
447 * @buf: temporary buffer
448 * @td: descriptor for the bad block table
450 * Read the bad block table by searching for a given ident pattern.
451 * Search is preformed either from the beginning up or from the end of
452 * the device downwards. The search starts always at the start of a
454 * If the option NAND_BBT_PERCHIP is given, each chip is searched
455 * for a bbt, which contains the bad block information of this chip.
456 * This is necessary to provide support for certain DOC devices.
458 * The bbt ident pattern resides in the oob area of the first page
461 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
463 struct nand_chip *this = mtd->priv;
465 int startblock, block, dir;
466 int scanlen = mtd->writesize + mtd->oobsize;
468 int blocktopage = this->bbt_erase_shift - this->page_shift;
470 /* Search direction top -> down ? */
471 if (td->options & NAND_BBT_LASTBLOCK) {
472 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
479 /* Do we have a bbt per chip ? */
480 if (td->options & NAND_BBT_PERCHIP) {
481 chips = this->numchips;
482 bbtblocks = this->chipsize >> this->bbt_erase_shift;
483 startblock &= bbtblocks - 1;
486 bbtblocks = mtd->size >> this->bbt_erase_shift;
489 for (i = 0; i < chips; i++) {
490 /* Reset version information */
493 /* Scan the maximum number of blocks */
494 for (block = 0; block < td->maxblocks; block++) {
496 int actblock = startblock + dir * block;
497 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
499 /* Read first page */
500 scan_read_raw(mtd, buf, offs, mtd->writesize);
501 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
502 td->pages[i] = actblock << blocktopage;
503 if (td->options & NAND_BBT_VERSION) {
504 td->version[i] = buf[mtd->writesize + td->veroffs];
509 startblock += this->chipsize >> this->bbt_erase_shift;
511 /* Check, if we found a bbt for each requested chip */
512 for (i = 0; i < chips; i++) {
513 if (td->pages[i] == -1)
514 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
516 printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i],
523 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
524 * @mtd: MTD device structure
525 * @buf: temporary buffer
526 * @td: descriptor for the bad block table
527 * @md: descriptor for the bad block table mirror
529 * Search and read the bad block table(s)
531 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
533 /* Search the primary table */
534 search_bbt(mtd, buf, td);
536 /* Search the mirror table */
538 search_bbt(mtd, buf, md);
540 /* Force result check */
545 * write_bbt - [GENERIC] (Re)write the bad block table
547 * @mtd: MTD device structure
548 * @buf: temporary buffer
549 * @td: descriptor for the bad block table
550 * @md: descriptor for the bad block table mirror
551 * @chipsel: selector for a specific chip, -1 for all
553 * (Re)write the bad block table
556 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
557 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
560 struct nand_chip *this = mtd->priv;
561 struct erase_info einfo;
562 int i, j, res, chip = 0;
563 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
564 int nrchips, bbtoffs, pageoffs, ooboffs;
566 uint8_t rcode = td->reserved_block_code;
567 size_t retlen, len = 0;
569 struct mtd_oob_ops ops;
571 ops.ooblen = mtd->oobsize;
574 ops.mode = MTD_OOB_PLACE;
578 /* Write bad block table per chip rather than per device ? */
579 if (td->options & NAND_BBT_PERCHIP) {
580 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
581 /* Full device write or specific chip ? */
583 nrchips = this->numchips;
585 nrchips = chipsel + 1;
589 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
593 /* Loop through the chips */
594 for (; chip < nrchips; chip++) {
596 /* There was already a version of the table, reuse the page
597 * This applies for absolute placement too, as we have the
598 * page nr. in td->pages.
600 if (td->pages[chip] != -1) {
601 page = td->pages[chip];
605 /* Automatic placement of the bad block table */
606 /* Search direction top -> down ? */
607 if (td->options & NAND_BBT_LASTBLOCK) {
608 startblock = numblocks * (chip + 1) - 1;
611 startblock = chip * numblocks;
615 for (i = 0; i < td->maxblocks; i++) {
616 int block = startblock + dir * i;
617 /* Check, if the block is bad */
618 switch ((this->bbt[block >> 2] >>
619 (2 * (block & 0x03))) & 0x03) {
625 (this->bbt_erase_shift - this->page_shift);
626 /* Check, if the block is used by the mirror table */
627 if (!md || md->pages[chip] != page)
630 printk(KERN_ERR "No space left to write bad block table\n");
634 /* Set up shift count and masks for the flash table */
635 bits = td->options & NAND_BBT_NRBITS_MSK;
638 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
641 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
644 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
647 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
650 default: return -EINVAL;
653 bbtoffs = chip * (numblocks >> 2);
655 to = ((loff_t) page) << this->page_shift;
657 /* Must we save the block contents ? */
658 if (td->options & NAND_BBT_SAVECONTENT) {
659 /* Make it block aligned */
660 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
661 len = 1 << this->bbt_erase_shift;
662 res = mtd->read(mtd, to, len, &retlen, buf);
665 printk(KERN_INFO "nand_bbt: Error "
666 "reading block for writing "
667 "the bad block table\n");
670 printk(KERN_WARNING "nand_bbt: ECC error "
671 "while reading block for writing "
672 "bad block table\n");
675 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
676 ops.oobbuf = &buf[len];
677 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
678 if (res < 0 || ops.oobretlen != ops.ooblen)
681 /* Calc the byte offset in the buffer */
682 pageoffs = page - (int)(to >> this->page_shift);
683 offs = pageoffs << this->page_shift;
684 /* Preset the bbt area with 0xff */
685 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
686 ooboffs = len + (pageoffs * mtd->oobsize);
690 len = (size_t) (numblocks >> sft);
691 /* Make it page aligned ! */
692 len = (len + (mtd->writesize - 1)) &
693 ~(mtd->writesize - 1);
694 /* Preset the buffer with 0xff */
695 memset(buf, 0xff, len +
696 (len >> this->page_shift)* mtd->oobsize);
699 /* Pattern is located in oob area of first page */
700 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
703 if (td->options & NAND_BBT_VERSION)
704 buf[ooboffs + td->veroffs] = td->version[chip];
706 /* walk through the memory table */
707 for (i = 0; i < numblocks;) {
709 dat = this->bbt[bbtoffs + (i >> 2)];
710 for (j = 0; j < 4; j++, i++) {
711 int sftcnt = (i << (3 - sft)) & sftmsk;
712 /* Do not store the reserved bbt blocks ! */
713 buf[offs + (i >> sft)] &=
714 ~(msk[dat & 0x03] << sftcnt);
719 memset(&einfo, 0, sizeof(einfo));
722 einfo.len = 1 << this->bbt_erase_shift;
723 res = nand_erase_nand(mtd, &einfo, 1);
727 res = scan_write_bbt(mtd, to, len, buf, &buf[len]);
731 printk(KERN_DEBUG "Bad block table written to 0x%012llx, "
732 "version 0x%02X\n", (unsigned long long)to,
735 /* Mark it as used */
736 td->pages[chip] = page;
742 "nand_bbt: Error while writing bad block table %d\n", res);
747 * nand_memory_bbt - [GENERIC] create a memory based bad block table
748 * @mtd: MTD device structure
749 * @bd: descriptor for the good/bad block search pattern
751 * The function creates a memory based bbt by scanning the device
752 * for manufacturer / software marked good / bad blocks
754 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
756 struct nand_chip *this = mtd->priv;
758 bd->options &= ~NAND_BBT_SCANEMPTY;
759 return create_bbt(mtd, this->buffers->databuf, bd, -1);
763 * check_create - [GENERIC] create and write bbt(s) if necessary
764 * @mtd: MTD device structure
765 * @buf: temporary buffer
766 * @bd: descriptor for the good/bad block search pattern
768 * The function checks the results of the previous call to read_bbt
769 * and creates / updates the bbt(s) if necessary
770 * Creation is necessary if no bbt was found for the chip/device
771 * Update is necessary if one of the tables is missing or the
772 * version nr. of one table is less than the other
774 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
776 int i, chips, writeops, chipsel, res;
777 struct nand_chip *this = mtd->priv;
778 struct nand_bbt_descr *td = this->bbt_td;
779 struct nand_bbt_descr *md = this->bbt_md;
780 struct nand_bbt_descr *rd, *rd2;
782 /* Do we have a bbt per chip ? */
783 if (td->options & NAND_BBT_PERCHIP)
784 chips = this->numchips;
788 for (i = 0; i < chips; i++) {
792 /* Per chip or per device ? */
793 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
794 /* Mirrored table avilable ? */
796 if (td->pages[i] == -1 && md->pages[i] == -1) {
801 if (td->pages[i] == -1) {
803 td->version[i] = md->version[i];
808 if (md->pages[i] == -1) {
810 md->version[i] = td->version[i];
815 if (td->version[i] == md->version[i]) {
817 if (!(td->options & NAND_BBT_VERSION))
822 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
824 md->version[i] = td->version[i];
828 td->version[i] = md->version[i];
835 if (td->pages[i] == -1) {
843 /* Create the bad block table by scanning the device ? */
844 if (!(td->options & NAND_BBT_CREATE))
847 /* Create the table in memory by scanning the chip(s) */
848 create_bbt(mtd, buf, bd, chipsel);
854 /* read back first ? */
856 read_abs_bbt(mtd, buf, rd, chipsel);
857 /* If they weren't versioned, read both. */
859 read_abs_bbt(mtd, buf, rd2, chipsel);
861 /* Write the bad block table to the device ? */
862 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
863 res = write_bbt(mtd, buf, td, md, chipsel);
868 /* Write the mirror bad block table to the device ? */
869 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
870 res = write_bbt(mtd, buf, md, td, chipsel);
879 * mark_bbt_regions - [GENERIC] mark the bad block table regions
880 * @mtd: MTD device structure
881 * @td: bad block table descriptor
883 * The bad block table regions are marked as "bad" to prevent
884 * accidental erasures / writes. The regions are identified by
887 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
889 struct nand_chip *this = mtd->priv;
890 int i, j, chips, block, nrblocks, update;
891 uint8_t oldval, newval;
893 /* Do we have a bbt per chip ? */
894 if (td->options & NAND_BBT_PERCHIP) {
895 chips = this->numchips;
896 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
899 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
902 for (i = 0; i < chips; i++) {
903 if ((td->options & NAND_BBT_ABSPAGE) ||
904 !(td->options & NAND_BBT_WRITE)) {
905 if (td->pages[i] == -1)
907 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
909 oldval = this->bbt[(block >> 3)];
910 newval = oldval | (0x2 << (block & 0x06));
911 this->bbt[(block >> 3)] = newval;
912 if ((oldval != newval) && td->reserved_block_code)
913 nand_update_bbt(mtd, (loff_t)block <<
914 (this->bbt_erase_shift - 1));
918 if (td->options & NAND_BBT_LASTBLOCK)
919 block = ((i + 1) * nrblocks) - td->maxblocks;
921 block = i * nrblocks;
923 for (j = 0; j < td->maxblocks; j++) {
924 oldval = this->bbt[(block >> 3)];
925 newval = oldval | (0x2 << (block & 0x06));
926 this->bbt[(block >> 3)] = newval;
927 if (oldval != newval)
931 /* If we want reserved blocks to be recorded to flash, and some
932 new ones have been marked, then we need to update the stored
933 bbts. This should only happen once. */
934 if (update && td->reserved_block_code)
935 nand_update_bbt(mtd, (loff_t)(block - 2) <<
936 (this->bbt_erase_shift - 1));
941 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
942 * @mtd: MTD device structure
943 * @bd: descriptor for the good/bad block search pattern
945 * The function checks, if a bad block table(s) is/are already
946 * available. If not it scans the device for manufacturer
947 * marked good / bad blocks and writes the bad block table(s) to
948 * the selected place.
950 * The bad block table memory is allocated here. It must be freed
951 * by calling the nand_free_bbt function.
954 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
956 struct nand_chip *this = mtd->priv;
959 struct nand_bbt_descr *td = this->bbt_td;
960 struct nand_bbt_descr *md = this->bbt_md;
962 len = mtd->size >> (this->bbt_erase_shift + 2);
963 /* Allocate memory (2bit per block) and clear the memory bad block table */
964 this->bbt = kzalloc(len, GFP_KERNEL);
966 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
970 /* If no primary table decriptor is given, scan the device
971 * to build a memory based bad block table
974 if ((res = nand_memory_bbt(mtd, bd))) {
975 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
982 /* Allocate a temporary buffer for one eraseblock incl. oob */
983 len = (1 << this->bbt_erase_shift);
984 len += (len >> this->page_shift) * mtd->oobsize;
987 printk(KERN_ERR "nand_bbt: Out of memory\n");
993 /* Is the bbt at a given page ? */
994 if (td->options & NAND_BBT_ABSPAGE) {
995 res = read_abs_bbts(mtd, buf, td, md);
997 /* Search the bad block table using a pattern in oob */
998 res = search_read_bbts(mtd, buf, td, md);
1002 res = check_create(mtd, buf, bd);
1004 /* Prevent the bbt regions from erasing / writing */
1005 mark_bbt_region(mtd, td);
1007 mark_bbt_region(mtd, md);
1014 * nand_update_bbt - [NAND Interface] update bad block table(s)
1015 * @mtd: MTD device structure
1016 * @offs: the offset of the newly marked block
1018 * The function updates the bad block table(s)
1020 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1022 struct nand_chip *this = mtd->priv;
1023 int len, res = 0, writeops = 0;
1026 struct nand_bbt_descr *td = this->bbt_td;
1027 struct nand_bbt_descr *md = this->bbt_md;
1029 if (!this->bbt || !td)
1032 /* Allocate a temporary buffer for one eraseblock incl. oob */
1033 len = (1 << this->bbt_erase_shift);
1034 len += (len >> this->page_shift) * mtd->oobsize;
1035 buf = kmalloc(len, GFP_KERNEL);
1037 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1041 writeops = md != NULL ? 0x03 : 0x01;
1043 /* Do we have a bbt per chip ? */
1044 if (td->options & NAND_BBT_PERCHIP) {
1045 chip = (int)(offs >> this->chip_shift);
1052 td->version[chip]++;
1054 md->version[chip]++;
1056 /* Write the bad block table to the device ? */
1057 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1058 res = write_bbt(mtd, buf, td, md, chipsel);
1062 /* Write the mirror bad block table to the device ? */
1063 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1064 res = write_bbt(mtd, buf, md, td, chipsel);
1072 /* Define some generic bad / good block scan pattern which are used
1073 * while scanning a device for factory marked good / bad blocks. */
1074 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1076 static struct nand_bbt_descr smallpage_memorybased = {
1077 .options = NAND_BBT_SCAN2NDPAGE,
1080 .pattern = scan_ff_pattern
1083 static struct nand_bbt_descr largepage_memorybased = {
1087 .pattern = scan_ff_pattern
1090 static struct nand_bbt_descr smallpage_flashbased = {
1091 .options = NAND_BBT_SCAN2NDPAGE,
1094 .pattern = scan_ff_pattern
1097 static struct nand_bbt_descr largepage_flashbased = {
1098 .options = NAND_BBT_SCAN2NDPAGE,
1101 .pattern = scan_ff_pattern
1104 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1106 static struct nand_bbt_descr agand_flashbased = {
1107 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1110 .pattern = scan_agand_pattern
1113 /* Generic flash bbt decriptors
1115 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1116 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1118 static struct nand_bbt_descr bbt_main_descr = {
1119 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1120 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1125 .pattern = bbt_pattern
1128 static struct nand_bbt_descr bbt_mirror_descr = {
1129 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1130 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1135 .pattern = mirror_pattern
1139 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1140 * @mtd: MTD device structure
1142 * This function selects the default bad block table
1143 * support for the device and calls the nand_scan_bbt function
1146 int nand_default_bbt(struct mtd_info *mtd)
1148 struct nand_chip *this = mtd->priv;
1150 /* Default for AG-AND. We must use a flash based
1151 * bad block table as the devices have factory marked
1152 * _good_ blocks. Erasing those blocks leads to loss
1153 * of the good / bad information, so we _must_ store
1154 * this information in a good / bad table during
1157 if (this->options & NAND_IS_AND) {
1158 /* Use the default pattern descriptors */
1159 if (!this->bbt_td) {
1160 this->bbt_td = &bbt_main_descr;
1161 this->bbt_md = &bbt_mirror_descr;
1163 this->options |= NAND_USE_FLASH_BBT;
1164 return nand_scan_bbt(mtd, &agand_flashbased);
1167 /* Is a flash based bad block table requested ? */
1168 if (this->options & NAND_USE_FLASH_BBT) {
1169 /* Use the default pattern descriptors */
1170 if (!this->bbt_td) {
1171 this->bbt_td = &bbt_main_descr;
1172 this->bbt_md = &bbt_mirror_descr;
1174 if (!this->badblock_pattern) {
1175 this->badblock_pattern = (mtd->writesize > 512) ? &largepage_flashbased : &smallpage_flashbased;
1178 this->bbt_td = NULL;
1179 this->bbt_md = NULL;
1180 if (!this->badblock_pattern) {
1181 this->badblock_pattern = (mtd->writesize > 512) ?
1182 &largepage_memorybased : &smallpage_memorybased;
1185 return nand_scan_bbt(mtd, this->badblock_pattern);
1189 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1190 * @mtd: MTD device structure
1191 * @offs: offset in the device
1192 * @allowbbt: allow access to bad block table region
1195 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1197 struct nand_chip *this = mtd->priv;
1201 /* Get block number * 2 */
1202 block = (int)(offs >> (this->bbt_erase_shift - 1));
1203 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1205 MTDDEBUG (MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1206 "(block %d) 0x%02x\n", (unsigned int)offs, res, block >> 1);
1214 return allowbbt ? 0 : 1;