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22 * If one of the bbt's is out of date or does not exist it is (re)created.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 bits, 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 /* Number of bits for each erase block in the bbt */
490 bits = td->options & NAND_BBT_NRBITS_MSK;
492 for (i = 0; i < chips; i++) {
493 /* Reset version information */
496 /* Scan the maximum number of blocks */
497 for (block = 0; block < td->maxblocks; block++) {
499 int actblock = startblock + dir * block;
500 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
502 /* Read first page */
503 scan_read_raw(mtd, buf, offs, mtd->writesize);
504 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
505 td->pages[i] = actblock << blocktopage;
506 if (td->options & NAND_BBT_VERSION) {
507 td->version[i] = buf[mtd->writesize + td->veroffs];
512 startblock += this->chipsize >> this->bbt_erase_shift;
514 /* Check, if we found a bbt for each requested chip */
515 for (i = 0; i < chips; i++) {
516 if (td->pages[i] == -1)
517 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
519 printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i],
526 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
527 * @mtd: MTD device structure
528 * @buf: temporary buffer
529 * @td: descriptor for the bad block table
530 * @md: descriptor for the bad block table mirror
532 * Search and read the bad block table(s)
534 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
536 /* Search the primary table */
537 search_bbt(mtd, buf, td);
539 /* Search the mirror table */
541 search_bbt(mtd, buf, md);
543 /* Force result check */
548 * write_bbt - [GENERIC] (Re)write the bad block table
550 * @mtd: MTD device structure
551 * @buf: temporary buffer
552 * @td: descriptor for the bad block table
553 * @md: descriptor for the bad block table mirror
554 * @chipsel: selector for a specific chip, -1 for all
556 * (Re)write the bad block table
559 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
560 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
563 struct nand_chip *this = mtd->priv;
564 struct erase_info einfo;
565 int i, j, res, chip = 0;
566 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
567 int nrchips, bbtoffs, pageoffs, ooboffs;
569 uint8_t rcode = td->reserved_block_code;
570 size_t retlen, len = 0;
572 struct mtd_oob_ops ops;
574 ops.ooblen = mtd->oobsize;
577 ops.mode = MTD_OOB_PLACE;
581 /* Write bad block table per chip rather than per device ? */
582 if (td->options & NAND_BBT_PERCHIP) {
583 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
584 /* Full device write or specific chip ? */
586 nrchips = this->numchips;
588 nrchips = chipsel + 1;
592 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
596 /* Loop through the chips */
597 for (; chip < nrchips; chip++) {
599 /* There was already a version of the table, reuse the page
600 * This applies for absolute placement too, as we have the
601 * page nr. in td->pages.
603 if (td->pages[chip] != -1) {
604 page = td->pages[chip];
608 /* Automatic placement of the bad block table */
609 /* Search direction top -> down ? */
610 if (td->options & NAND_BBT_LASTBLOCK) {
611 startblock = numblocks * (chip + 1) - 1;
614 startblock = chip * numblocks;
618 for (i = 0; i < td->maxblocks; i++) {
619 int block = startblock + dir * i;
620 /* Check, if the block is bad */
621 switch ((this->bbt[block >> 2] >>
622 (2 * (block & 0x03))) & 0x03) {
628 (this->bbt_erase_shift - this->page_shift);
629 /* Check, if the block is used by the mirror table */
630 if (!md || md->pages[chip] != page)
633 printk(KERN_ERR "No space left to write bad block table\n");
637 /* Set up shift count and masks for the flash table */
638 bits = td->options & NAND_BBT_NRBITS_MSK;
641 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
644 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
647 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
650 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
653 default: return -EINVAL;
656 bbtoffs = chip * (numblocks >> 2);
658 to = ((loff_t) page) << this->page_shift;
660 /* Must we save the block contents ? */
661 if (td->options & NAND_BBT_SAVECONTENT) {
662 /* Make it block aligned */
663 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
664 len = 1 << this->bbt_erase_shift;
665 res = mtd->read(mtd, to, len, &retlen, buf);
668 printk(KERN_INFO "nand_bbt: Error "
669 "reading block for writing "
670 "the bad block table\n");
673 printk(KERN_WARNING "nand_bbt: ECC error "
674 "while reading block for writing "
675 "bad block table\n");
678 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
679 ops.oobbuf = &buf[len];
680 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
681 if (res < 0 || ops.oobretlen != ops.ooblen)
684 /* Calc the byte offset in the buffer */
685 pageoffs = page - (int)(to >> this->page_shift);
686 offs = pageoffs << this->page_shift;
687 /* Preset the bbt area with 0xff */
688 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
689 ooboffs = len + (pageoffs * mtd->oobsize);
693 len = (size_t) (numblocks >> sft);
694 /* Make it page aligned ! */
695 len = (len + (mtd->writesize - 1)) &
696 ~(mtd->writesize - 1);
697 /* Preset the buffer with 0xff */
698 memset(buf, 0xff, len +
699 (len >> this->page_shift)* mtd->oobsize);
702 /* Pattern is located in oob area of first page */
703 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
706 if (td->options & NAND_BBT_VERSION)
707 buf[ooboffs + td->veroffs] = td->version[chip];
709 /* walk through the memory table */
710 for (i = 0; i < numblocks;) {
712 dat = this->bbt[bbtoffs + (i >> 2)];
713 for (j = 0; j < 4; j++, i++) {
714 int sftcnt = (i << (3 - sft)) & sftmsk;
715 /* Do not store the reserved bbt blocks ! */
716 buf[offs + (i >> sft)] &=
717 ~(msk[dat & 0x03] << sftcnt);
722 memset(&einfo, 0, sizeof(einfo));
725 einfo.len = 1 << this->bbt_erase_shift;
726 res = nand_erase_nand(mtd, &einfo, 1);
730 res = scan_write_bbt(mtd, to, len, buf, &buf[len]);
734 printk(KERN_DEBUG "Bad block table written to 0x%012llx, "
735 "version 0x%02X\n", (unsigned long long)to,
738 /* Mark it as used */
739 td->pages[chip] = page;
745 "nand_bbt: Error while writing bad block table %d\n", res);
750 * nand_memory_bbt - [GENERIC] create a memory based bad block table
751 * @mtd: MTD device structure
752 * @bd: descriptor for the good/bad block search pattern
754 * The function creates a memory based bbt by scanning the device
755 * for manufacturer / software marked good / bad blocks
757 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
759 struct nand_chip *this = mtd->priv;
761 bd->options &= ~NAND_BBT_SCANEMPTY;
762 return create_bbt(mtd, this->buffers->databuf, bd, -1);
766 * check_create - [GENERIC] create and write bbt(s) if necessary
767 * @mtd: MTD device structure
768 * @buf: temporary buffer
769 * @bd: descriptor for the good/bad block search pattern
771 * The function checks the results of the previous call to read_bbt
772 * and creates / updates the bbt(s) if necessary
773 * Creation is necessary if no bbt was found for the chip/device
774 * Update is necessary if one of the tables is missing or the
775 * version nr. of one table is less than the other
777 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
779 int i, chips, writeops, chipsel, res;
780 struct nand_chip *this = mtd->priv;
781 struct nand_bbt_descr *td = this->bbt_td;
782 struct nand_bbt_descr *md = this->bbt_md;
783 struct nand_bbt_descr *rd, *rd2;
785 /* Do we have a bbt per chip ? */
786 if (td->options & NAND_BBT_PERCHIP)
787 chips = this->numchips;
791 for (i = 0; i < chips; i++) {
795 /* Per chip or per device ? */
796 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
797 /* Mirrored table avilable ? */
799 if (td->pages[i] == -1 && md->pages[i] == -1) {
804 if (td->pages[i] == -1) {
806 td->version[i] = md->version[i];
811 if (md->pages[i] == -1) {
813 md->version[i] = td->version[i];
818 if (td->version[i] == md->version[i]) {
820 if (!(td->options & NAND_BBT_VERSION))
825 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
827 md->version[i] = td->version[i];
831 td->version[i] = md->version[i];
838 if (td->pages[i] == -1) {
846 /* Create the bad block table by scanning the device ? */
847 if (!(td->options & NAND_BBT_CREATE))
850 /* Create the table in memory by scanning the chip(s) */
851 create_bbt(mtd, buf, bd, chipsel);
857 /* read back first ? */
859 read_abs_bbt(mtd, buf, rd, chipsel);
860 /* If they weren't versioned, read both. */
862 read_abs_bbt(mtd, buf, rd2, chipsel);
864 /* Write the bad block table to the device ? */
865 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
866 res = write_bbt(mtd, buf, td, md, chipsel);
871 /* Write the mirror bad block table to the device ? */
872 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
873 res = write_bbt(mtd, buf, md, td, chipsel);
882 * mark_bbt_regions - [GENERIC] mark the bad block table regions
883 * @mtd: MTD device structure
884 * @td: bad block table descriptor
886 * The bad block table regions are marked as "bad" to prevent
887 * accidental erasures / writes. The regions are identified by
890 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
892 struct nand_chip *this = mtd->priv;
893 int i, j, chips, block, nrblocks, update;
894 uint8_t oldval, newval;
896 /* Do we have a bbt per chip ? */
897 if (td->options & NAND_BBT_PERCHIP) {
898 chips = this->numchips;
899 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
902 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
905 for (i = 0; i < chips; i++) {
906 if ((td->options & NAND_BBT_ABSPAGE) ||
907 !(td->options & NAND_BBT_WRITE)) {
908 if (td->pages[i] == -1)
910 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
912 oldval = this->bbt[(block >> 3)];
913 newval = oldval | (0x2 << (block & 0x06));
914 this->bbt[(block >> 3)] = newval;
915 if ((oldval != newval) && td->reserved_block_code)
916 nand_update_bbt(mtd, (loff_t)block <<
917 (this->bbt_erase_shift - 1));
921 if (td->options & NAND_BBT_LASTBLOCK)
922 block = ((i + 1) * nrblocks) - td->maxblocks;
924 block = i * nrblocks;
926 for (j = 0; j < td->maxblocks; j++) {
927 oldval = this->bbt[(block >> 3)];
928 newval = oldval | (0x2 << (block & 0x06));
929 this->bbt[(block >> 3)] = newval;
930 if (oldval != newval)
934 /* If we want reserved blocks to be recorded to flash, and some
935 new ones have been marked, then we need to update the stored
936 bbts. This should only happen once. */
937 if (update && td->reserved_block_code)
938 nand_update_bbt(mtd, (loff_t)(block - 2) <<
939 (this->bbt_erase_shift - 1));
944 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
945 * @mtd: MTD device structure
946 * @bd: descriptor for the good/bad block search pattern
948 * The function checks, if a bad block table(s) is/are already
949 * available. If not it scans the device for manufacturer
950 * marked good / bad blocks and writes the bad block table(s) to
951 * the selected place.
953 * The bad block table memory is allocated here. It must be freed
954 * by calling the nand_free_bbt function.
957 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
959 struct nand_chip *this = mtd->priv;
962 struct nand_bbt_descr *td = this->bbt_td;
963 struct nand_bbt_descr *md = this->bbt_md;
965 len = mtd->size >> (this->bbt_erase_shift + 2);
966 /* Allocate memory (2bit per block) and clear the memory bad block table */
967 this->bbt = kzalloc(len, GFP_KERNEL);
969 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
973 /* If no primary table decriptor is given, scan the device
974 * to build a memory based bad block table
977 if ((res = nand_memory_bbt(mtd, bd))) {
978 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
985 /* Allocate a temporary buffer for one eraseblock incl. oob */
986 len = (1 << this->bbt_erase_shift);
987 len += (len >> this->page_shift) * mtd->oobsize;
990 printk(KERN_ERR "nand_bbt: Out of memory\n");
996 /* Is the bbt at a given page ? */
997 if (td->options & NAND_BBT_ABSPAGE) {
998 res = read_abs_bbts(mtd, buf, td, md);
1000 /* Search the bad block table using a pattern in oob */
1001 res = search_read_bbts(mtd, buf, td, md);
1005 res = check_create(mtd, buf, bd);
1007 /* Prevent the bbt regions from erasing / writing */
1008 mark_bbt_region(mtd, td);
1010 mark_bbt_region(mtd, md);
1017 * nand_update_bbt - [NAND Interface] update bad block table(s)
1018 * @mtd: MTD device structure
1019 * @offs: the offset of the newly marked block
1021 * The function updates the bad block table(s)
1023 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1025 struct nand_chip *this = mtd->priv;
1026 int len, res = 0, writeops = 0;
1029 struct nand_bbt_descr *td = this->bbt_td;
1030 struct nand_bbt_descr *md = this->bbt_md;
1032 if (!this->bbt || !td)
1035 /* Allocate a temporary buffer for one eraseblock incl. oob */
1036 len = (1 << this->bbt_erase_shift);
1037 len += (len >> this->page_shift) * mtd->oobsize;
1038 buf = kmalloc(len, GFP_KERNEL);
1040 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1044 writeops = md != NULL ? 0x03 : 0x01;
1046 /* Do we have a bbt per chip ? */
1047 if (td->options & NAND_BBT_PERCHIP) {
1048 chip = (int)(offs >> this->chip_shift);
1055 td->version[chip]++;
1057 md->version[chip]++;
1059 /* Write the bad block table to the device ? */
1060 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1061 res = write_bbt(mtd, buf, td, md, chipsel);
1065 /* Write the mirror bad block table to the device ? */
1066 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1067 res = write_bbt(mtd, buf, md, td, chipsel);
1075 /* Define some generic bad / good block scan pattern which are used
1076 * while scanning a device for factory marked good / bad blocks. */
1077 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1079 static struct nand_bbt_descr smallpage_memorybased = {
1080 .options = NAND_BBT_SCAN2NDPAGE,
1083 .pattern = scan_ff_pattern
1086 static struct nand_bbt_descr largepage_memorybased = {
1090 .pattern = scan_ff_pattern
1093 static struct nand_bbt_descr smallpage_flashbased = {
1094 .options = NAND_BBT_SCAN2NDPAGE,
1097 .pattern = scan_ff_pattern
1100 static struct nand_bbt_descr largepage_flashbased = {
1101 .options = NAND_BBT_SCAN2NDPAGE,
1104 .pattern = scan_ff_pattern
1107 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1109 static struct nand_bbt_descr agand_flashbased = {
1110 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1113 .pattern = scan_agand_pattern
1116 /* Generic flash bbt decriptors
1118 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1119 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1121 static struct nand_bbt_descr bbt_main_descr = {
1122 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1123 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1128 .pattern = bbt_pattern
1131 static struct nand_bbt_descr bbt_mirror_descr = {
1132 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1133 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1138 .pattern = mirror_pattern
1142 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1143 * @mtd: MTD device structure
1145 * This function selects the default bad block table
1146 * support for the device and calls the nand_scan_bbt function
1149 int nand_default_bbt(struct mtd_info *mtd)
1151 struct nand_chip *this = mtd->priv;
1153 /* Default for AG-AND. We must use a flash based
1154 * bad block table as the devices have factory marked
1155 * _good_ blocks. Erasing those blocks leads to loss
1156 * of the good / bad information, so we _must_ store
1157 * this information in a good / bad table during
1160 if (this->options & NAND_IS_AND) {
1161 /* Use the default pattern descriptors */
1162 if (!this->bbt_td) {
1163 this->bbt_td = &bbt_main_descr;
1164 this->bbt_md = &bbt_mirror_descr;
1166 this->options |= NAND_USE_FLASH_BBT;
1167 return nand_scan_bbt(mtd, &agand_flashbased);
1170 /* Is a flash based bad block table requested ? */
1171 if (this->options & NAND_USE_FLASH_BBT) {
1172 /* Use the default pattern descriptors */
1173 if (!this->bbt_td) {
1174 this->bbt_td = &bbt_main_descr;
1175 this->bbt_md = &bbt_mirror_descr;
1177 if (!this->badblock_pattern) {
1178 this->badblock_pattern = (mtd->writesize > 512) ? &largepage_flashbased : &smallpage_flashbased;
1181 this->bbt_td = NULL;
1182 this->bbt_md = NULL;
1183 if (!this->badblock_pattern) {
1184 this->badblock_pattern = (mtd->writesize > 512) ?
1185 &largepage_memorybased : &smallpage_memorybased;
1188 return nand_scan_bbt(mtd, this->badblock_pattern);
1192 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1193 * @mtd: MTD device structure
1194 * @offs: offset in the device
1195 * @allowbbt: allow access to bad block table region
1198 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1200 struct nand_chip *this = mtd->priv;
1204 /* Get block number * 2 */
1205 block = (int)(offs >> (this->bbt_erase_shift - 1));
1206 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1208 MTDDEBUG (MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1209 "(block %d) 0x%02x\n", (unsigned int)offs, res, block >> 1);
1217 return allowbbt ? 0 : 1;