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22 * If one of the bbt's is out of date or does not exist it is (re)created.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/bitops.h>
59 #include <linux/delay.h>
60 #include <linux/vmalloc.h>
63 * check_pattern - [GENERIC] check if a pattern is in the buffer
64 * @buf: the buffer to search
65 * @len: the length of buffer to search
66 * @paglen: the pagelength
67 * @td: search pattern descriptor
69 * Check for a pattern at the given place. Used to search bad block
70 * tables and good / bad block identifiers.
71 * If the SCAN_EMPTY option is set then check, if all bytes except the
72 * pattern area contain 0xff
75 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
80 end = paglen + td->offs;
81 if (td->options & NAND_BBT_SCANEMPTY) {
82 for (i = 0; i < end; i++) {
89 /* Compare the pattern */
90 for (i = 0; i < td->len; i++) {
91 if (p[i] != td->pattern[i])
95 /* Check both positions 1 and 6 for pattern? */
96 if (td->options & NAND_BBT_SCANBYTE1AND6) {
97 if (td->options & NAND_BBT_SCANEMPTY) {
99 end += NAND_SMALL_BADBLOCK_POS - td->offs;
100 /* Check region between positions 1 and 6 */
101 for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
108 p += NAND_SMALL_BADBLOCK_POS - td->offs;
110 /* Compare the pattern */
111 for (i = 0; i < td->len; i++) {
112 if (p[i] != td->pattern[i])
117 if (td->options & NAND_BBT_SCANEMPTY) {
120 for (i = end; i < len; i++) {
129 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
130 * @buf: the buffer to search
131 * @td: search pattern descriptor
133 * Check for a pattern at the given place. Used to search bad block
134 * tables and good / bad block identifiers. Same as check_pattern, but
135 * no optional empty check
138 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
143 /* Compare the pattern */
144 for (i = 0; i < td->len; i++) {
145 if (p[td->offs + i] != td->pattern[i])
148 /* Need to check location 1 AND 6? */
149 if (td->options & NAND_BBT_SCANBYTE1AND6) {
150 for (i = 0; i < td->len; i++) {
151 if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
159 * read_bbt - [GENERIC] Read the bad block table starting from page
160 * @mtd: MTD device structure
161 * @buf: temporary buffer
162 * @page: the starting page
163 * @num: the number of bbt descriptors to read
164 * @bits: number of bits per block
165 * @offs: offset in the memory table
166 * @reserved_block_code: Pattern to identify reserved blocks
168 * Read the bad block table starting from page.
171 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
172 int bits, int offs, int reserved_block_code)
174 int res, i, j, act = 0;
175 struct nand_chip *this = mtd->priv;
176 size_t retlen, len, totlen;
178 uint8_t msk = (uint8_t) ((1 << bits) - 1);
180 totlen = (num * bits) >> 3;
181 from = ((loff_t) page) << this->page_shift;
184 len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
185 res = mtd->read(mtd, from, len, &retlen, buf);
188 printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
191 printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
195 for (i = 0; i < len; i++) {
196 uint8_t dat = buf[i];
197 for (j = 0; j < 8; j += bits, act += 2) {
198 uint8_t tmp = (dat >> j) & msk;
201 if (reserved_block_code && (tmp == reserved_block_code)) {
202 printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n",
203 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
204 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
205 mtd->ecc_stats.bbtblocks++;
208 /* Leave it for now, if its matured we can move this
209 * message to MTD_DEBUG_LEVEL0 */
210 printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n",
211 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
212 /* Factory marked bad or worn out ? */
214 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
216 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
217 mtd->ecc_stats.badblocks++;
227 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
228 * @mtd: MTD device structure
229 * @buf: temporary buffer
230 * @td: descriptor for the bad block table
231 * @chip: read the table for a specific chip, -1 read all chips.
232 * Applies only if NAND_BBT_PERCHIP option is set
234 * Read the bad block table for all chips starting at a given page
235 * We assume that the bbt bits are in consecutive order.
237 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
239 struct nand_chip *this = mtd->priv;
243 bits = td->options & NAND_BBT_NRBITS_MSK;
244 if (td->options & NAND_BBT_PERCHIP) {
246 for (i = 0; i < this->numchips; i++) {
247 if (chip == -1 || chip == i)
248 res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
251 offs += this->chipsize >> (this->bbt_erase_shift + 2);
254 res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
262 * Scan read raw data from flash
264 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
267 struct mtd_oob_ops ops;
270 ops.mode = MTD_OOB_RAW;
272 ops.ooblen = mtd->oobsize;
276 if (len <= mtd->writesize) {
277 ops.oobbuf = buf + len;
280 return mtd->read_oob(mtd, offs, &ops);
282 ops.oobbuf = buf + mtd->writesize;
284 ops.len = mtd->writesize;
285 res = mtd->read_oob(mtd, offs, &ops);
291 buf += mtd->oobsize + mtd->writesize;
292 len -= mtd->writesize;
298 * Scan write data with oob to flash
300 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
301 uint8_t *buf, uint8_t *oob)
303 struct mtd_oob_ops ops;
305 ops.mode = MTD_OOB_PLACE;
307 ops.ooblen = mtd->oobsize;
312 return mtd->write_oob(mtd, offs, &ops);
316 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
317 * @mtd: MTD device structure
318 * @buf: temporary buffer
319 * @td: descriptor for the bad block table
320 * @md: descriptor for the bad block table mirror
322 * Read the bad block table(s) for all chips starting at a given page
323 * We assume that the bbt bits are in consecutive order.
326 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
327 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
329 struct nand_chip *this = mtd->priv;
331 /* Read the primary version, if available */
332 if (td->options & NAND_BBT_VERSION) {
333 scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
335 td->version[0] = buf[mtd->writesize + td->veroffs];
336 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
337 td->pages[0], td->version[0]);
340 /* Read the mirror version, if available */
341 if (md && (md->options & NAND_BBT_VERSION)) {
342 scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
344 md->version[0] = buf[mtd->writesize + md->veroffs];
345 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
346 md->pages[0], md->version[0]);
352 * Scan a given block full
354 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
355 loff_t offs, uint8_t *buf, size_t readlen,
356 int scanlen, int len)
360 ret = scan_read_raw(mtd, buf, offs, readlen);
364 for (j = 0; j < len; j++, buf += scanlen) {
365 if (check_pattern(buf, scanlen, mtd->writesize, bd))
372 * Scan a given block partially
374 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
375 loff_t offs, uint8_t *buf, int len)
377 struct mtd_oob_ops ops;
380 ops.ooblen = mtd->oobsize;
384 ops.mode = MTD_OOB_PLACE;
386 for (j = 0; j < len; j++) {
388 * Read the full oob until read_oob is fixed to
389 * handle single byte reads for 16 bit
392 ret = mtd->read_oob(mtd, offs, &ops);
396 if (check_short_pattern(buf, bd))
399 offs += mtd->writesize;
405 * create_bbt - [GENERIC] Create a bad block table by scanning the device
406 * @mtd: MTD device structure
407 * @buf: temporary buffer
408 * @bd: descriptor for the good/bad block search pattern
409 * @chip: create the table for a specific chip, -1 read all chips.
410 * Applies only if NAND_BBT_PERCHIP option is set
412 * Create a bad block table by scanning the device
413 * for the given good/bad block identify pattern
415 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
416 struct nand_bbt_descr *bd, int chip)
418 struct nand_chip *this = mtd->priv;
419 int i, numblocks, len, scanlen;
424 printk(KERN_INFO "Scanning device for bad blocks\n");
426 if (bd->options & NAND_BBT_SCANALLPAGES)
427 len = 1 << (this->bbt_erase_shift - this->page_shift);
428 else if (bd->options & NAND_BBT_SCAN2NDPAGE)
433 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
434 /* We need only read few bytes from the OOB area */
438 /* Full page content should be read */
439 scanlen = mtd->writesize + mtd->oobsize;
440 readlen = len * mtd->writesize;
444 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
445 * below as it makes shifting and masking less painful */
446 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
450 if (chip >= this->numchips) {
451 printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
452 chip + 1, this->numchips);
455 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
456 startblock = chip * numblocks;
457 numblocks += startblock;
458 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
461 if (this->options & NAND_BBT_SCANLASTPAGE)
462 from += mtd->erasesize - (mtd->writesize * len);
464 for (i = startblock; i < numblocks;) {
467 if (bd->options & NAND_BBT_SCANALLPAGES)
468 ret = scan_block_full(mtd, bd, from, buf, readlen,
471 ret = scan_block_fast(mtd, bd, from, buf, len);
477 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
478 printk(KERN_WARNING "Bad eraseblock %d at 0x%012llx\n",
479 i >> 1, (unsigned long long)from);
480 mtd->ecc_stats.badblocks++;
484 from += (1 << this->bbt_erase_shift);
490 * search_bbt - [GENERIC] scan the device for a specific bad block table
491 * @mtd: MTD device structure
492 * @buf: temporary buffer
493 * @td: descriptor for the bad block table
495 * Read the bad block table by searching for a given ident pattern.
496 * Search is preformed either from the beginning up or from the end of
497 * the device downwards. The search starts always at the start of a
499 * If the option NAND_BBT_PERCHIP is given, each chip is searched
500 * for a bbt, which contains the bad block information of this chip.
501 * This is necessary to provide support for certain DOC devices.
503 * The bbt ident pattern resides in the oob area of the first page
506 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
508 struct nand_chip *this = mtd->priv;
510 int bits, startblock, block, dir;
511 int scanlen = mtd->writesize + mtd->oobsize;
513 int blocktopage = this->bbt_erase_shift - this->page_shift;
515 /* Search direction top -> down ? */
516 if (td->options & NAND_BBT_LASTBLOCK) {
517 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
524 /* Do we have a bbt per chip ? */
525 if (td->options & NAND_BBT_PERCHIP) {
526 chips = this->numchips;
527 bbtblocks = this->chipsize >> this->bbt_erase_shift;
528 startblock &= bbtblocks - 1;
531 bbtblocks = mtd->size >> this->bbt_erase_shift;
534 /* Number of bits for each erase block in the bbt */
535 bits = td->options & NAND_BBT_NRBITS_MSK;
537 for (i = 0; i < chips; i++) {
538 /* Reset version information */
541 /* Scan the maximum number of blocks */
542 for (block = 0; block < td->maxblocks; block++) {
544 int actblock = startblock + dir * block;
545 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
547 /* Read first page */
548 scan_read_raw(mtd, buf, offs, mtd->writesize);
549 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
550 td->pages[i] = actblock << blocktopage;
551 if (td->options & NAND_BBT_VERSION) {
552 td->version[i] = buf[mtd->writesize + td->veroffs];
557 startblock += this->chipsize >> this->bbt_erase_shift;
559 /* Check, if we found a bbt for each requested chip */
560 for (i = 0; i < chips; i++) {
561 if (td->pages[i] == -1)
562 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
564 printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i],
571 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
572 * @mtd: MTD device structure
573 * @buf: temporary buffer
574 * @td: descriptor for the bad block table
575 * @md: descriptor for the bad block table mirror
577 * Search and read the bad block table(s)
579 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
581 /* Search the primary table */
582 search_bbt(mtd, buf, td);
584 /* Search the mirror table */
586 search_bbt(mtd, buf, md);
588 /* Force result check */
593 * write_bbt - [GENERIC] (Re)write the bad block table
595 * @mtd: MTD device structure
596 * @buf: temporary buffer
597 * @td: descriptor for the bad block table
598 * @md: descriptor for the bad block table mirror
599 * @chipsel: selector for a specific chip, -1 for all
601 * (Re)write the bad block table
604 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
605 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
608 struct nand_chip *this = mtd->priv;
609 struct erase_info einfo;
610 int i, j, res, chip = 0;
611 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
612 int nrchips, bbtoffs, pageoffs, ooboffs;
614 uint8_t rcode = td->reserved_block_code;
615 size_t retlen, len = 0;
617 struct mtd_oob_ops ops;
619 ops.ooblen = mtd->oobsize;
622 ops.mode = MTD_OOB_PLACE;
626 /* Write bad block table per chip rather than per device ? */
627 if (td->options & NAND_BBT_PERCHIP) {
628 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
629 /* Full device write or specific chip ? */
631 nrchips = this->numchips;
633 nrchips = chipsel + 1;
637 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
641 /* Loop through the chips */
642 for (; chip < nrchips; chip++) {
644 /* There was already a version of the table, reuse the page
645 * This applies for absolute placement too, as we have the
646 * page nr. in td->pages.
648 if (td->pages[chip] != -1) {
649 page = td->pages[chip];
653 /* Automatic placement of the bad block table */
654 /* Search direction top -> down ? */
655 if (td->options & NAND_BBT_LASTBLOCK) {
656 startblock = numblocks * (chip + 1) - 1;
659 startblock = chip * numblocks;
663 for (i = 0; i < td->maxblocks; i++) {
664 int block = startblock + dir * i;
665 /* Check, if the block is bad */
666 switch ((this->bbt[block >> 2] >>
667 (2 * (block & 0x03))) & 0x03) {
673 (this->bbt_erase_shift - this->page_shift);
674 /* Check, if the block is used by the mirror table */
675 if (!md || md->pages[chip] != page)
678 printk(KERN_ERR "No space left to write bad block table\n");
682 /* Set up shift count and masks for the flash table */
683 bits = td->options & NAND_BBT_NRBITS_MSK;
686 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
689 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
692 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
695 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
698 default: return -EINVAL;
701 bbtoffs = chip * (numblocks >> 2);
703 to = ((loff_t) page) << this->page_shift;
705 /* Must we save the block contents ? */
706 if (td->options & NAND_BBT_SAVECONTENT) {
707 /* Make it block aligned */
708 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
709 len = 1 << this->bbt_erase_shift;
710 res = mtd->read(mtd, to, len, &retlen, buf);
713 printk(KERN_INFO "nand_bbt: Error "
714 "reading block for writing "
715 "the bad block table\n");
718 printk(KERN_WARNING "nand_bbt: ECC error "
719 "while reading block for writing "
720 "bad block table\n");
723 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
724 ops.oobbuf = &buf[len];
725 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
726 if (res < 0 || ops.oobretlen != ops.ooblen)
729 /* Calc the byte offset in the buffer */
730 pageoffs = page - (int)(to >> this->page_shift);
731 offs = pageoffs << this->page_shift;
732 /* Preset the bbt area with 0xff */
733 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
734 ooboffs = len + (pageoffs * mtd->oobsize);
738 len = (size_t) (numblocks >> sft);
739 /* Make it page aligned ! */
740 len = (len + (mtd->writesize - 1)) &
741 ~(mtd->writesize - 1);
742 /* Preset the buffer with 0xff */
743 memset(buf, 0xff, len +
744 (len >> this->page_shift)* mtd->oobsize);
747 /* Pattern is located in oob area of first page */
748 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
751 if (td->options & NAND_BBT_VERSION)
752 buf[ooboffs + td->veroffs] = td->version[chip];
754 /* walk through the memory table */
755 for (i = 0; i < numblocks;) {
757 dat = this->bbt[bbtoffs + (i >> 2)];
758 for (j = 0; j < 4; j++, i++) {
759 int sftcnt = (i << (3 - sft)) & sftmsk;
760 /* Do not store the reserved bbt blocks ! */
761 buf[offs + (i >> sft)] &=
762 ~(msk[dat & 0x03] << sftcnt);
767 memset(&einfo, 0, sizeof(einfo));
770 einfo.len = 1 << this->bbt_erase_shift;
771 res = nand_erase_nand(mtd, &einfo, 1);
775 res = scan_write_bbt(mtd, to, len, buf, &buf[len]);
779 printk(KERN_DEBUG "Bad block table written to 0x%012llx, version "
780 "0x%02X\n", (unsigned long long)to, td->version[chip]);
782 /* Mark it as used */
783 td->pages[chip] = page;
789 "nand_bbt: Error while writing bad block table %d\n", res);
794 * nand_memory_bbt - [GENERIC] create a memory based bad block table
795 * @mtd: MTD device structure
796 * @bd: descriptor for the good/bad block search pattern
798 * The function creates a memory based bbt by scanning the device
799 * for manufacturer / software marked good / bad blocks
801 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
803 struct nand_chip *this = mtd->priv;
805 bd->options &= ~NAND_BBT_SCANEMPTY;
806 return create_bbt(mtd, this->buffers->databuf, bd, -1);
810 * check_create - [GENERIC] create and write bbt(s) if necessary
811 * @mtd: MTD device structure
812 * @buf: temporary buffer
813 * @bd: descriptor for the good/bad block search pattern
815 * The function checks the results of the previous call to read_bbt
816 * and creates / updates the bbt(s) if necessary
817 * Creation is necessary if no bbt was found for the chip/device
818 * Update is necessary if one of the tables is missing or the
819 * version nr. of one table is less than the other
821 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
823 int i, chips, writeops, chipsel, res;
824 struct nand_chip *this = mtd->priv;
825 struct nand_bbt_descr *td = this->bbt_td;
826 struct nand_bbt_descr *md = this->bbt_md;
827 struct nand_bbt_descr *rd, *rd2;
829 /* Do we have a bbt per chip ? */
830 if (td->options & NAND_BBT_PERCHIP)
831 chips = this->numchips;
835 for (i = 0; i < chips; i++) {
839 /* Per chip or per device ? */
840 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
841 /* Mirrored table avilable ? */
843 if (td->pages[i] == -1 && md->pages[i] == -1) {
848 if (td->pages[i] == -1) {
850 td->version[i] = md->version[i];
855 if (md->pages[i] == -1) {
857 md->version[i] = td->version[i];
862 if (td->version[i] == md->version[i]) {
864 if (!(td->options & NAND_BBT_VERSION))
869 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
871 md->version[i] = td->version[i];
875 td->version[i] = md->version[i];
882 if (td->pages[i] == -1) {
890 /* Create the bad block table by scanning the device ? */
891 if (!(td->options & NAND_BBT_CREATE))
894 /* Create the table in memory by scanning the chip(s) */
895 create_bbt(mtd, buf, bd, chipsel);
901 /* read back first ? */
903 read_abs_bbt(mtd, buf, rd, chipsel);
904 /* If they weren't versioned, read both. */
906 read_abs_bbt(mtd, buf, rd2, chipsel);
908 /* Write the bad block table to the device ? */
909 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
910 res = write_bbt(mtd, buf, td, md, chipsel);
915 /* Write the mirror bad block table to the device ? */
916 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
917 res = write_bbt(mtd, buf, md, td, chipsel);
926 * mark_bbt_regions - [GENERIC] mark the bad block table regions
927 * @mtd: MTD device structure
928 * @td: bad block table descriptor
930 * The bad block table regions are marked as "bad" to prevent
931 * accidental erasures / writes. The regions are identified by
934 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
936 struct nand_chip *this = mtd->priv;
937 int i, j, chips, block, nrblocks, update;
938 uint8_t oldval, newval;
940 /* Do we have a bbt per chip ? */
941 if (td->options & NAND_BBT_PERCHIP) {
942 chips = this->numchips;
943 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
946 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
949 for (i = 0; i < chips; i++) {
950 if ((td->options & NAND_BBT_ABSPAGE) ||
951 !(td->options & NAND_BBT_WRITE)) {
952 if (td->pages[i] == -1)
954 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
956 oldval = this->bbt[(block >> 3)];
957 newval = oldval | (0x2 << (block & 0x06));
958 this->bbt[(block >> 3)] = newval;
959 if ((oldval != newval) && td->reserved_block_code)
960 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
964 if (td->options & NAND_BBT_LASTBLOCK)
965 block = ((i + 1) * nrblocks) - td->maxblocks;
967 block = i * nrblocks;
969 for (j = 0; j < td->maxblocks; j++) {
970 oldval = this->bbt[(block >> 3)];
971 newval = oldval | (0x2 << (block & 0x06));
972 this->bbt[(block >> 3)] = newval;
973 if (oldval != newval)
977 /* If we want reserved blocks to be recorded to flash, and some
978 new ones have been marked, then we need to update the stored
979 bbts. This should only happen once. */
980 if (update && td->reserved_block_code)
981 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
986 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
987 * @mtd: MTD device structure
988 * @bd: descriptor for the good/bad block search pattern
990 * The function checks, if a bad block table(s) is/are already
991 * available. If not it scans the device for manufacturer
992 * marked good / bad blocks and writes the bad block table(s) to
993 * the selected place.
995 * The bad block table memory is allocated here. It must be freed
996 * by calling the nand_free_bbt function.
999 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1001 struct nand_chip *this = mtd->priv;
1004 struct nand_bbt_descr *td = this->bbt_td;
1005 struct nand_bbt_descr *md = this->bbt_md;
1007 len = mtd->size >> (this->bbt_erase_shift + 2);
1008 /* Allocate memory (2bit per block) and clear the memory bad block table */
1009 this->bbt = kzalloc(len, GFP_KERNEL);
1011 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
1015 /* If no primary table decriptor is given, scan the device
1016 * to build a memory based bad block table
1019 if ((res = nand_memory_bbt(mtd, bd))) {
1020 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1027 /* Allocate a temporary buffer for one eraseblock incl. oob */
1028 len = (1 << this->bbt_erase_shift);
1029 len += (len >> this->page_shift) * mtd->oobsize;
1032 printk(KERN_ERR "nand_bbt: Out of memory\n");
1038 /* Is the bbt at a given page ? */
1039 if (td->options & NAND_BBT_ABSPAGE) {
1040 res = read_abs_bbts(mtd, buf, td, md);
1042 /* Search the bad block table using a pattern in oob */
1043 res = search_read_bbts(mtd, buf, td, md);
1047 res = check_create(mtd, buf, bd);
1049 /* Prevent the bbt regions from erasing / writing */
1050 mark_bbt_region(mtd, td);
1052 mark_bbt_region(mtd, md);
1059 * nand_update_bbt - [NAND Interface] update bad block table(s)
1060 * @mtd: MTD device structure
1061 * @offs: the offset of the newly marked block
1063 * The function updates the bad block table(s)
1065 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1067 struct nand_chip *this = mtd->priv;
1068 int len, res = 0, writeops = 0;
1071 struct nand_bbt_descr *td = this->bbt_td;
1072 struct nand_bbt_descr *md = this->bbt_md;
1074 if (!this->bbt || !td)
1077 /* Allocate a temporary buffer for one eraseblock incl. oob */
1078 len = (1 << this->bbt_erase_shift);
1079 len += (len >> this->page_shift) * mtd->oobsize;
1080 buf = kmalloc(len, GFP_KERNEL);
1082 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1086 writeops = md != NULL ? 0x03 : 0x01;
1088 /* Do we have a bbt per chip ? */
1089 if (td->options & NAND_BBT_PERCHIP) {
1090 chip = (int)(offs >> this->chip_shift);
1097 td->version[chip]++;
1099 md->version[chip]++;
1101 /* Write the bad block table to the device ? */
1102 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1103 res = write_bbt(mtd, buf, td, md, chipsel);
1107 /* Write the mirror bad block table to the device ? */
1108 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1109 res = write_bbt(mtd, buf, md, td, chipsel);
1117 /* Define some generic bad / good block scan pattern which are used
1118 * while scanning a device for factory marked good / bad blocks. */
1119 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1121 static struct nand_bbt_descr smallpage_flashbased = {
1122 .options = NAND_BBT_SCAN2NDPAGE,
1123 .offs = NAND_SMALL_BADBLOCK_POS,
1125 .pattern = scan_ff_pattern
1128 static struct nand_bbt_descr largepage_flashbased = {
1129 .options = NAND_BBT_SCAN2NDPAGE,
1130 .offs = NAND_LARGE_BADBLOCK_POS,
1132 .pattern = scan_ff_pattern
1135 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1137 static struct nand_bbt_descr agand_flashbased = {
1138 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1141 .pattern = scan_agand_pattern
1144 /* Generic flash bbt decriptors
1146 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1147 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1149 static struct nand_bbt_descr bbt_main_descr = {
1150 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1151 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1156 .pattern = bbt_pattern
1159 static struct nand_bbt_descr bbt_mirror_descr = {
1160 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1161 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1166 .pattern = mirror_pattern
1169 #define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
1170 NAND_BBT_SCANBYTE1AND6)
1172 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1173 * @this: NAND chip to create descriptor for
1175 * This function allocates and initializes a nand_bbt_descr for BBM detection
1176 * based on the properties of "this". The new descriptor is stored in
1177 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1178 * passed to this function.
1180 * TODO: Handle other flags, replace other static structs
1181 * (e.g. handle NAND_BBT_FLASH for flash-based BBT,
1182 * replace smallpage_flashbased)
1185 static int nand_create_default_bbt_descr(struct nand_chip *this)
1187 struct nand_bbt_descr *bd;
1188 if (this->badblock_pattern) {
1189 printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
1192 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1194 printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
1197 bd->options = this->options & BBT_SCAN_OPTIONS;
1198 bd->offs = this->badblockpos;
1199 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1200 bd->pattern = scan_ff_pattern;
1201 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1202 this->badblock_pattern = bd;
1207 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1208 * @mtd: MTD device structure
1210 * This function selects the default bad block table
1211 * support for the device and calls the nand_scan_bbt function
1214 int nand_default_bbt(struct mtd_info *mtd)
1216 struct nand_chip *this = mtd->priv;
1218 /* Default for AG-AND. We must use a flash based
1219 * bad block table as the devices have factory marked
1220 * _good_ blocks. Erasing those blocks leads to loss
1221 * of the good / bad information, so we _must_ store
1222 * this information in a good / bad table during
1225 if (this->options & NAND_IS_AND) {
1226 /* Use the default pattern descriptors */
1227 if (!this->bbt_td) {
1228 this->bbt_td = &bbt_main_descr;
1229 this->bbt_md = &bbt_mirror_descr;
1231 this->options |= NAND_USE_FLASH_BBT;
1232 return nand_scan_bbt(mtd, &agand_flashbased);
1235 /* Is a flash based bad block table requested ? */
1236 if (this->options & NAND_USE_FLASH_BBT) {
1237 /* Use the default pattern descriptors */
1238 if (!this->bbt_td) {
1239 this->bbt_td = &bbt_main_descr;
1240 this->bbt_md = &bbt_mirror_descr;
1242 if (!this->badblock_pattern) {
1243 this->badblock_pattern = (mtd->writesize > 512) ? &largepage_flashbased : &smallpage_flashbased;
1246 this->bbt_td = NULL;
1247 this->bbt_md = NULL;
1248 if (!this->badblock_pattern)
1249 nand_create_default_bbt_descr(this);
1251 return nand_scan_bbt(mtd, this->badblock_pattern);
1255 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1256 * @mtd: MTD device structure
1257 * @offs: offset in the device
1258 * @allowbbt: allow access to bad block table region
1261 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1263 struct nand_chip *this = mtd->priv;
1267 /* Get block number * 2 */
1268 block = (int)(offs >> (this->bbt_erase_shift - 1));
1269 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1271 DEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1272 (unsigned int)offs, block >> 1, res);
1280 return allowbbt ? 0 : 1;
1285 EXPORT_SYMBOL(nand_scan_bbt);
1286 EXPORT_SYMBOL(nand_default_bbt);