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22 * If one of the bbt's is out of date or does not exist it is (re)created.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
53 #include <linux/slab.h>
54 #include <linux/types.h>
55 #include <linux/mtd/mtd.h>
56 #include <linux/mtd/nand.h>
57 #include <linux/mtd/nand_ecc.h>
58 #include <linux/mtd/compatmac.h>
59 #include <linux/bitops.h>
60 #include <linux/delay.h>
61 #include <linux/vmalloc.h>
64 * check_pattern - [GENERIC] check if a pattern is in the buffer
65 * @buf: the buffer to search
66 * @len: the length of buffer to search
67 * @paglen: the pagelength
68 * @td: search pattern descriptor
70 * Check for a pattern at the given place. Used to search bad block
71 * tables and good / bad block identifiers.
72 * If the SCAN_EMPTY option is set then check, if all bytes except the
73 * pattern area contain 0xff
76 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
81 end = paglen + td->offs;
82 if (td->options & NAND_BBT_SCANEMPTY) {
83 for (i = 0; i < end; i++) {
90 /* Compare the pattern */
91 for (i = 0; i < td->len; i++) {
92 if (p[i] != td->pattern[i])
96 /* Check both positions 1 and 6 for pattern? */
97 if (td->options & NAND_BBT_SCANBYTE1AND6) {
98 if (td->options & NAND_BBT_SCANEMPTY) {
100 end += NAND_SMALL_BADBLOCK_POS - td->offs;
101 /* Check region between positions 1 and 6 */
102 for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
109 p += NAND_SMALL_BADBLOCK_POS - td->offs;
111 /* Compare the pattern */
112 for (i = 0; i < td->len; i++) {
113 if (p[i] != td->pattern[i])
118 if (td->options & NAND_BBT_SCANEMPTY) {
121 for (i = end; i < len; i++) {
130 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
131 * @buf: the buffer to search
132 * @td: search pattern descriptor
134 * Check for a pattern at the given place. Used to search bad block
135 * tables and good / bad block identifiers. Same as check_pattern, but
136 * no optional empty check
139 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
144 /* Compare the pattern */
145 for (i = 0; i < td->len; i++) {
146 if (p[td->offs + i] != td->pattern[i])
149 /* Need to check location 1 AND 6? */
150 if (td->options & NAND_BBT_SCANBYTE1AND6) {
151 for (i = 0; i < td->len; i++) {
152 if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
160 * read_bbt - [GENERIC] Read the bad block table starting from page
161 * @mtd: MTD device structure
162 * @buf: temporary buffer
163 * @page: the starting page
164 * @num: the number of bbt descriptors to read
165 * @bits: number of bits per block
166 * @offs: offset in the memory table
167 * @reserved_block_code: Pattern to identify reserved blocks
169 * Read the bad block table starting from page.
172 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
173 int bits, int offs, int reserved_block_code)
175 int res, i, j, act = 0;
176 struct nand_chip *this = mtd->priv;
177 size_t retlen, len, totlen;
179 uint8_t msk = (uint8_t) ((1 << bits) - 1);
181 totlen = (num * bits) >> 3;
182 from = ((loff_t) page) << this->page_shift;
185 len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
186 res = mtd->read(mtd, from, len, &retlen, buf);
189 printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
192 printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
196 for (i = 0; i < len; i++) {
197 uint8_t dat = buf[i];
198 for (j = 0; j < 8; j += bits, act += 2) {
199 uint8_t tmp = (dat >> j) & msk;
202 if (reserved_block_code && (tmp == reserved_block_code)) {
203 printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n",
204 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
205 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
206 mtd->ecc_stats.bbtblocks++;
209 /* Leave it for now, if its matured we can move this
210 * message to MTD_DEBUG_LEVEL0 */
211 printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n",
212 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
213 /* Factory marked bad or worn out ? */
215 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
217 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
218 mtd->ecc_stats.badblocks++;
228 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
229 * @mtd: MTD device structure
230 * @buf: temporary buffer
231 * @td: descriptor for the bad block table
232 * @chip: read the table for a specific chip, -1 read all chips.
233 * Applies only if NAND_BBT_PERCHIP option is set
235 * Read the bad block table for all chips starting at a given page
236 * We assume that the bbt bits are in consecutive order.
238 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
240 struct nand_chip *this = mtd->priv;
244 bits = td->options & NAND_BBT_NRBITS_MSK;
245 if (td->options & NAND_BBT_PERCHIP) {
247 for (i = 0; i < this->numchips; i++) {
248 if (chip == -1 || chip == i)
249 res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
252 offs += this->chipsize >> (this->bbt_erase_shift + 2);
255 res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
263 * Scan read raw data from flash
265 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
268 struct mtd_oob_ops ops;
271 ops.mode = MTD_OOB_RAW;
273 ops.ooblen = mtd->oobsize;
277 if (len <= mtd->writesize) {
278 ops.oobbuf = buf + len;
281 return mtd->read_oob(mtd, offs, &ops);
283 ops.oobbuf = buf + mtd->writesize;
285 ops.len = mtd->writesize;
286 res = mtd->read_oob(mtd, offs, &ops);
292 buf += mtd->oobsize + mtd->writesize;
293 len -= mtd->writesize;
299 * Scan write data with oob to flash
301 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
302 uint8_t *buf, uint8_t *oob)
304 struct mtd_oob_ops ops;
306 ops.mode = MTD_OOB_PLACE;
308 ops.ooblen = mtd->oobsize;
313 return mtd->write_oob(mtd, offs, &ops);
317 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
318 * @mtd: MTD device structure
319 * @buf: temporary buffer
320 * @td: descriptor for the bad block table
321 * @md: descriptor for the bad block table mirror
323 * Read the bad block table(s) for all chips starting at a given page
324 * We assume that the bbt bits are in consecutive order.
327 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
328 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
330 struct nand_chip *this = mtd->priv;
332 /* Read the primary version, if available */
333 if (td->options & NAND_BBT_VERSION) {
334 scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
336 td->version[0] = buf[mtd->writesize + td->veroffs];
337 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
338 td->pages[0], td->version[0]);
341 /* Read the mirror version, if available */
342 if (md && (md->options & NAND_BBT_VERSION)) {
343 scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
345 md->version[0] = buf[mtd->writesize + md->veroffs];
346 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
347 md->pages[0], md->version[0]);
353 * Scan a given block full
355 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
356 loff_t offs, uint8_t *buf, size_t readlen,
357 int scanlen, int len)
361 ret = scan_read_raw(mtd, buf, offs, readlen);
365 for (j = 0; j < len; j++, buf += scanlen) {
366 if (check_pattern(buf, scanlen, mtd->writesize, bd))
373 * Scan a given block partially
375 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
376 loff_t offs, uint8_t *buf, int len)
378 struct mtd_oob_ops ops;
381 ops.ooblen = mtd->oobsize;
385 ops.mode = MTD_OOB_PLACE;
387 for (j = 0; j < len; j++) {
389 * Read the full oob until read_oob is fixed to
390 * handle single byte reads for 16 bit
393 ret = mtd->read_oob(mtd, offs, &ops);
397 if (check_short_pattern(buf, bd))
400 offs += mtd->writesize;
406 * create_bbt - [GENERIC] Create a bad block table by scanning the device
407 * @mtd: MTD device structure
408 * @buf: temporary buffer
409 * @bd: descriptor for the good/bad block search pattern
410 * @chip: create the table for a specific chip, -1 read all chips.
411 * Applies only if NAND_BBT_PERCHIP option is set
413 * Create a bad block table by scanning the device
414 * for the given good/bad block identify pattern
416 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
417 struct nand_bbt_descr *bd, int chip)
419 struct nand_chip *this = mtd->priv;
420 int i, numblocks, len, scanlen;
425 printk(KERN_INFO "Scanning device for bad blocks\n");
427 if (bd->options & NAND_BBT_SCANALLPAGES)
428 len = 1 << (this->bbt_erase_shift - this->page_shift);
429 else if (bd->options & NAND_BBT_SCAN2NDPAGE)
434 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
435 /* We need only read few bytes from the OOB area */
439 /* Full page content should be read */
440 scanlen = mtd->writesize + mtd->oobsize;
441 readlen = len * mtd->writesize;
445 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
446 * below as it makes shifting and masking less painful */
447 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
451 if (chip >= this->numchips) {
452 printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
453 chip + 1, this->numchips);
456 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
457 startblock = chip * numblocks;
458 numblocks += startblock;
459 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
462 if (this->options & NAND_BBT_SCANLASTPAGE)
463 from += mtd->erasesize - (mtd->writesize * len);
465 for (i = startblock; i < numblocks;) {
468 if (bd->options & NAND_BBT_SCANALLPAGES)
469 ret = scan_block_full(mtd, bd, from, buf, readlen,
472 ret = scan_block_fast(mtd, bd, from, buf, len);
478 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
479 printk(KERN_WARNING "Bad eraseblock %d at 0x%012llx\n",
480 i >> 1, (unsigned long long)from);
481 mtd->ecc_stats.badblocks++;
485 from += (1 << this->bbt_erase_shift);
491 * search_bbt - [GENERIC] scan the device for a specific bad block table
492 * @mtd: MTD device structure
493 * @buf: temporary buffer
494 * @td: descriptor for the bad block table
496 * Read the bad block table by searching for a given ident pattern.
497 * Search is preformed either from the beginning up or from the end of
498 * the device downwards. The search starts always at the start of a
500 * If the option NAND_BBT_PERCHIP is given, each chip is searched
501 * for a bbt, which contains the bad block information of this chip.
502 * This is necessary to provide support for certain DOC devices.
504 * The bbt ident pattern resides in the oob area of the first page
507 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
509 struct nand_chip *this = mtd->priv;
511 int bits, startblock, block, dir;
512 int scanlen = mtd->writesize + mtd->oobsize;
514 int blocktopage = this->bbt_erase_shift - this->page_shift;
516 /* Search direction top -> down ? */
517 if (td->options & NAND_BBT_LASTBLOCK) {
518 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
525 /* Do we have a bbt per chip ? */
526 if (td->options & NAND_BBT_PERCHIP) {
527 chips = this->numchips;
528 bbtblocks = this->chipsize >> this->bbt_erase_shift;
529 startblock &= bbtblocks - 1;
532 bbtblocks = mtd->size >> this->bbt_erase_shift;
535 /* Number of bits for each erase block in the bbt */
536 bits = td->options & NAND_BBT_NRBITS_MSK;
538 for (i = 0; i < chips; i++) {
539 /* Reset version information */
542 /* Scan the maximum number of blocks */
543 for (block = 0; block < td->maxblocks; block++) {
545 int actblock = startblock + dir * block;
546 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
548 /* Read first page */
549 scan_read_raw(mtd, buf, offs, mtd->writesize);
550 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
551 td->pages[i] = actblock << blocktopage;
552 if (td->options & NAND_BBT_VERSION) {
553 td->version[i] = buf[mtd->writesize + td->veroffs];
558 startblock += this->chipsize >> this->bbt_erase_shift;
560 /* Check, if we found a bbt for each requested chip */
561 for (i = 0; i < chips; i++) {
562 if (td->pages[i] == -1)
563 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
565 printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i],
572 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
573 * @mtd: MTD device structure
574 * @buf: temporary buffer
575 * @td: descriptor for the bad block table
576 * @md: descriptor for the bad block table mirror
578 * Search and read the bad block table(s)
580 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
582 /* Search the primary table */
583 search_bbt(mtd, buf, td);
585 /* Search the mirror table */
587 search_bbt(mtd, buf, md);
589 /* Force result check */
594 * write_bbt - [GENERIC] (Re)write the bad block table
596 * @mtd: MTD device structure
597 * @buf: temporary buffer
598 * @td: descriptor for the bad block table
599 * @md: descriptor for the bad block table mirror
600 * @chipsel: selector for a specific chip, -1 for all
602 * (Re)write the bad block table
605 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
606 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
609 struct nand_chip *this = mtd->priv;
610 struct erase_info einfo;
611 int i, j, res, chip = 0;
612 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
613 int nrchips, bbtoffs, pageoffs, ooboffs;
615 uint8_t rcode = td->reserved_block_code;
616 size_t retlen, len = 0;
618 struct mtd_oob_ops ops;
620 ops.ooblen = mtd->oobsize;
623 ops.mode = MTD_OOB_PLACE;
627 /* Write bad block table per chip rather than per device ? */
628 if (td->options & NAND_BBT_PERCHIP) {
629 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
630 /* Full device write or specific chip ? */
632 nrchips = this->numchips;
634 nrchips = chipsel + 1;
638 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
642 /* Loop through the chips */
643 for (; chip < nrchips; chip++) {
645 /* There was already a version of the table, reuse the page
646 * This applies for absolute placement too, as we have the
647 * page nr. in td->pages.
649 if (td->pages[chip] != -1) {
650 page = td->pages[chip];
654 /* Automatic placement of the bad block table */
655 /* Search direction top -> down ? */
656 if (td->options & NAND_BBT_LASTBLOCK) {
657 startblock = numblocks * (chip + 1) - 1;
660 startblock = chip * numblocks;
664 for (i = 0; i < td->maxblocks; i++) {
665 int block = startblock + dir * i;
666 /* Check, if the block is bad */
667 switch ((this->bbt[block >> 2] >>
668 (2 * (block & 0x03))) & 0x03) {
674 (this->bbt_erase_shift - this->page_shift);
675 /* Check, if the block is used by the mirror table */
676 if (!md || md->pages[chip] != page)
679 printk(KERN_ERR "No space left to write bad block table\n");
683 /* Set up shift count and masks for the flash table */
684 bits = td->options & NAND_BBT_NRBITS_MSK;
687 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
690 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
693 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
696 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
699 default: return -EINVAL;
702 bbtoffs = chip * (numblocks >> 2);
704 to = ((loff_t) page) << this->page_shift;
706 /* Must we save the block contents ? */
707 if (td->options & NAND_BBT_SAVECONTENT) {
708 /* Make it block aligned */
709 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
710 len = 1 << this->bbt_erase_shift;
711 res = mtd->read(mtd, to, len, &retlen, buf);
714 printk(KERN_INFO "nand_bbt: Error "
715 "reading block for writing "
716 "the bad block table\n");
719 printk(KERN_WARNING "nand_bbt: ECC error "
720 "while reading block for writing "
721 "bad block table\n");
724 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
725 ops.oobbuf = &buf[len];
726 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
727 if (res < 0 || ops.oobretlen != ops.ooblen)
730 /* Calc the byte offset in the buffer */
731 pageoffs = page - (int)(to >> this->page_shift);
732 offs = pageoffs << this->page_shift;
733 /* Preset the bbt area with 0xff */
734 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
735 ooboffs = len + (pageoffs * mtd->oobsize);
739 len = (size_t) (numblocks >> sft);
740 /* Make it page aligned ! */
741 len = (len + (mtd->writesize - 1)) &
742 ~(mtd->writesize - 1);
743 /* Preset the buffer with 0xff */
744 memset(buf, 0xff, len +
745 (len >> this->page_shift)* mtd->oobsize);
748 /* Pattern is located in oob area of first page */
749 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
752 if (td->options & NAND_BBT_VERSION)
753 buf[ooboffs + td->veroffs] = td->version[chip];
755 /* walk through the memory table */
756 for (i = 0; i < numblocks;) {
758 dat = this->bbt[bbtoffs + (i >> 2)];
759 for (j = 0; j < 4; j++, i++) {
760 int sftcnt = (i << (3 - sft)) & sftmsk;
761 /* Do not store the reserved bbt blocks ! */
762 buf[offs + (i >> sft)] &=
763 ~(msk[dat & 0x03] << sftcnt);
768 memset(&einfo, 0, sizeof(einfo));
771 einfo.len = 1 << this->bbt_erase_shift;
772 res = nand_erase_nand(mtd, &einfo, 1);
776 res = scan_write_bbt(mtd, to, len, buf, &buf[len]);
780 printk(KERN_DEBUG "Bad block table written to 0x%012llx, version "
781 "0x%02X\n", (unsigned long long)to, td->version[chip]);
783 /* Mark it as used */
784 td->pages[chip] = page;
790 "nand_bbt: Error while writing bad block table %d\n", res);
795 * nand_memory_bbt - [GENERIC] create a memory based bad block table
796 * @mtd: MTD device structure
797 * @bd: descriptor for the good/bad block search pattern
799 * The function creates a memory based bbt by scanning the device
800 * for manufacturer / software marked good / bad blocks
802 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
804 struct nand_chip *this = mtd->priv;
806 bd->options &= ~NAND_BBT_SCANEMPTY;
807 return create_bbt(mtd, this->buffers->databuf, bd, -1);
811 * check_create - [GENERIC] create and write bbt(s) if necessary
812 * @mtd: MTD device structure
813 * @buf: temporary buffer
814 * @bd: descriptor for the good/bad block search pattern
816 * The function checks the results of the previous call to read_bbt
817 * and creates / updates the bbt(s) if necessary
818 * Creation is necessary if no bbt was found for the chip/device
819 * Update is necessary if one of the tables is missing or the
820 * version nr. of one table is less than the other
822 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
824 int i, chips, writeops, chipsel, res;
825 struct nand_chip *this = mtd->priv;
826 struct nand_bbt_descr *td = this->bbt_td;
827 struct nand_bbt_descr *md = this->bbt_md;
828 struct nand_bbt_descr *rd, *rd2;
830 /* Do we have a bbt per chip ? */
831 if (td->options & NAND_BBT_PERCHIP)
832 chips = this->numchips;
836 for (i = 0; i < chips; i++) {
840 /* Per chip or per device ? */
841 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
842 /* Mirrored table avilable ? */
844 if (td->pages[i] == -1 && md->pages[i] == -1) {
849 if (td->pages[i] == -1) {
851 td->version[i] = md->version[i];
856 if (md->pages[i] == -1) {
858 md->version[i] = td->version[i];
863 if (td->version[i] == md->version[i]) {
865 if (!(td->options & NAND_BBT_VERSION))
870 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
872 md->version[i] = td->version[i];
876 td->version[i] = md->version[i];
883 if (td->pages[i] == -1) {
891 /* Create the bad block table by scanning the device ? */
892 if (!(td->options & NAND_BBT_CREATE))
895 /* Create the table in memory by scanning the chip(s) */
896 create_bbt(mtd, buf, bd, chipsel);
902 /* read back first ? */
904 read_abs_bbt(mtd, buf, rd, chipsel);
905 /* If they weren't versioned, read both. */
907 read_abs_bbt(mtd, buf, rd2, chipsel);
909 /* Write the bad block table to the device ? */
910 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
911 res = write_bbt(mtd, buf, td, md, chipsel);
916 /* Write the mirror bad block table to the device ? */
917 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
918 res = write_bbt(mtd, buf, md, td, chipsel);
927 * mark_bbt_regions - [GENERIC] mark the bad block table regions
928 * @mtd: MTD device structure
929 * @td: bad block table descriptor
931 * The bad block table regions are marked as "bad" to prevent
932 * accidental erasures / writes. The regions are identified by
935 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
937 struct nand_chip *this = mtd->priv;
938 int i, j, chips, block, nrblocks, update;
939 uint8_t oldval, newval;
941 /* Do we have a bbt per chip ? */
942 if (td->options & NAND_BBT_PERCHIP) {
943 chips = this->numchips;
944 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
947 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
950 for (i = 0; i < chips; i++) {
951 if ((td->options & NAND_BBT_ABSPAGE) ||
952 !(td->options & NAND_BBT_WRITE)) {
953 if (td->pages[i] == -1)
955 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
957 oldval = this->bbt[(block >> 3)];
958 newval = oldval | (0x2 << (block & 0x06));
959 this->bbt[(block >> 3)] = newval;
960 if ((oldval != newval) && td->reserved_block_code)
961 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
965 if (td->options & NAND_BBT_LASTBLOCK)
966 block = ((i + 1) * nrblocks) - td->maxblocks;
968 block = i * nrblocks;
970 for (j = 0; j < td->maxblocks; j++) {
971 oldval = this->bbt[(block >> 3)];
972 newval = oldval | (0x2 << (block & 0x06));
973 this->bbt[(block >> 3)] = newval;
974 if (oldval != newval)
978 /* If we want reserved blocks to be recorded to flash, and some
979 new ones have been marked, then we need to update the stored
980 bbts. This should only happen once. */
981 if (update && td->reserved_block_code)
982 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
987 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
988 * @mtd: MTD device structure
989 * @bd: descriptor for the good/bad block search pattern
991 * The function checks, if a bad block table(s) is/are already
992 * available. If not it scans the device for manufacturer
993 * marked good / bad blocks and writes the bad block table(s) to
994 * the selected place.
996 * The bad block table memory is allocated here. It must be freed
997 * by calling the nand_free_bbt function.
1000 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1002 struct nand_chip *this = mtd->priv;
1005 struct nand_bbt_descr *td = this->bbt_td;
1006 struct nand_bbt_descr *md = this->bbt_md;
1008 len = mtd->size >> (this->bbt_erase_shift + 2);
1009 /* Allocate memory (2bit per block) and clear the memory bad block table */
1010 this->bbt = kzalloc(len, GFP_KERNEL);
1012 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
1016 /* If no primary table decriptor is given, scan the device
1017 * to build a memory based bad block table
1020 if ((res = nand_memory_bbt(mtd, bd))) {
1021 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1028 /* Allocate a temporary buffer for one eraseblock incl. oob */
1029 len = (1 << this->bbt_erase_shift);
1030 len += (len >> this->page_shift) * mtd->oobsize;
1033 printk(KERN_ERR "nand_bbt: Out of memory\n");
1039 /* Is the bbt at a given page ? */
1040 if (td->options & NAND_BBT_ABSPAGE) {
1041 res = read_abs_bbts(mtd, buf, td, md);
1043 /* Search the bad block table using a pattern in oob */
1044 res = search_read_bbts(mtd, buf, td, md);
1048 res = check_create(mtd, buf, bd);
1050 /* Prevent the bbt regions from erasing / writing */
1051 mark_bbt_region(mtd, td);
1053 mark_bbt_region(mtd, md);
1060 * nand_update_bbt - [NAND Interface] update bad block table(s)
1061 * @mtd: MTD device structure
1062 * @offs: the offset of the newly marked block
1064 * The function updates the bad block table(s)
1066 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1068 struct nand_chip *this = mtd->priv;
1069 int len, res = 0, writeops = 0;
1072 struct nand_bbt_descr *td = this->bbt_td;
1073 struct nand_bbt_descr *md = this->bbt_md;
1075 if (!this->bbt || !td)
1078 /* Allocate a temporary buffer for one eraseblock incl. oob */
1079 len = (1 << this->bbt_erase_shift);
1080 len += (len >> this->page_shift) * mtd->oobsize;
1081 buf = kmalloc(len, GFP_KERNEL);
1083 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1087 writeops = md != NULL ? 0x03 : 0x01;
1089 /* Do we have a bbt per chip ? */
1090 if (td->options & NAND_BBT_PERCHIP) {
1091 chip = (int)(offs >> this->chip_shift);
1098 td->version[chip]++;
1100 md->version[chip]++;
1102 /* Write the bad block table to the device ? */
1103 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1104 res = write_bbt(mtd, buf, td, md, chipsel);
1108 /* Write the mirror bad block table to the device ? */
1109 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1110 res = write_bbt(mtd, buf, md, td, chipsel);
1118 /* Define some generic bad / good block scan pattern which are used
1119 * while scanning a device for factory marked good / bad blocks. */
1120 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1122 static struct nand_bbt_descr smallpage_flashbased = {
1123 .options = NAND_BBT_SCAN2NDPAGE,
1124 .offs = NAND_SMALL_BADBLOCK_POS,
1126 .pattern = scan_ff_pattern
1129 static struct nand_bbt_descr largepage_flashbased = {
1130 .options = NAND_BBT_SCAN2NDPAGE,
1131 .offs = NAND_LARGE_BADBLOCK_POS,
1133 .pattern = scan_ff_pattern
1136 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1138 static struct nand_bbt_descr agand_flashbased = {
1139 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1142 .pattern = scan_agand_pattern
1145 /* Generic flash bbt decriptors
1147 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1148 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1150 static struct nand_bbt_descr bbt_main_descr = {
1151 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1152 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1157 .pattern = bbt_pattern
1160 static struct nand_bbt_descr bbt_mirror_descr = {
1161 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1162 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1167 .pattern = mirror_pattern
1170 #define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
1171 NAND_BBT_SCANBYTE1AND6)
1173 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1174 * @this: NAND chip to create descriptor for
1176 * This function allocates and initializes a nand_bbt_descr for BBM detection
1177 * based on the properties of "this". The new descriptor is stored in
1178 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1179 * passed to this function.
1181 * TODO: Handle other flags, replace other static structs
1182 * (e.g. handle NAND_BBT_FLASH for flash-based BBT,
1183 * replace smallpage_flashbased)
1186 static int nand_create_default_bbt_descr(struct nand_chip *this)
1188 struct nand_bbt_descr *bd;
1189 if (this->badblock_pattern) {
1190 printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
1193 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1195 printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
1198 bd->options = this->options & BBT_SCAN_OPTIONS;
1199 bd->offs = this->badblockpos;
1200 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1201 bd->pattern = scan_ff_pattern;
1202 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1203 this->badblock_pattern = bd;
1208 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1209 * @mtd: MTD device structure
1211 * This function selects the default bad block table
1212 * support for the device and calls the nand_scan_bbt function
1215 int nand_default_bbt(struct mtd_info *mtd)
1217 struct nand_chip *this = mtd->priv;
1219 /* Default for AG-AND. We must use a flash based
1220 * bad block table as the devices have factory marked
1221 * _good_ blocks. Erasing those blocks leads to loss
1222 * of the good / bad information, so we _must_ store
1223 * this information in a good / bad table during
1226 if (this->options & NAND_IS_AND) {
1227 /* Use the default pattern descriptors */
1228 if (!this->bbt_td) {
1229 this->bbt_td = &bbt_main_descr;
1230 this->bbt_md = &bbt_mirror_descr;
1232 this->options |= NAND_USE_FLASH_BBT;
1233 return nand_scan_bbt(mtd, &agand_flashbased);
1236 /* Is a flash based bad block table requested ? */
1237 if (this->options & NAND_USE_FLASH_BBT) {
1238 /* Use the default pattern descriptors */
1239 if (!this->bbt_td) {
1240 this->bbt_td = &bbt_main_descr;
1241 this->bbt_md = &bbt_mirror_descr;
1243 if (!this->badblock_pattern) {
1244 this->badblock_pattern = (mtd->writesize > 512) ? &largepage_flashbased : &smallpage_flashbased;
1247 this->bbt_td = NULL;
1248 this->bbt_md = NULL;
1249 if (!this->badblock_pattern)
1250 nand_create_default_bbt_descr(this);
1252 return nand_scan_bbt(mtd, this->badblock_pattern);
1256 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1257 * @mtd: MTD device structure
1258 * @offs: offset in the device
1259 * @allowbbt: allow access to bad block table region
1262 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1264 struct nand_chip *this = mtd->priv;
1268 /* Get block number * 2 */
1269 block = (int)(offs >> (this->bbt_erase_shift - 1));
1270 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1272 DEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1273 (unsigned int)offs, block >> 1, res);
1281 return allowbbt ? 0 : 1;
1286 EXPORT_SYMBOL(nand_scan_bbt);
1287 EXPORT_SYMBOL(nand_default_bbt);