2 * drivers/mtd/nand_bbt.c
5 * Bad block table support for the NAND driver
7 * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de)
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
15 * When nand_scan_bbt is called, then it tries to find the bad block table
16 * depending on the options in the BBT descriptor(s). If no flash based BBT
17 * (NAND_USE_FLASH_BBT) is specified then the device is scanned for factory
18 * marked good / bad blocks. This information is used to create a memory BBT.
19 * Once a new bad block is discovered then the "factory" information is updated
21 * If a flash based BBT is specified then the function first tries to find the
22 * BBT on flash. If a BBT is found then the contents are read and the memory
23 * based BBT is created. If a mirrored BBT is selected then the mirror is
24 * searched too and the versions are compared. If the mirror has a greater
25 * version number than the mirror BBT is used to build the memory based BBT.
26 * If the tables are not versioned, then we "or" the bad block information.
27 * If one of the BBTs is out of date or does not exist it is (re)created.
28 * If no BBT exists at all then the device is scanned for factory marked
29 * good / bad blocks and the bad block tables are created.
31 * For manufacturer created BBTs like the one found on M-SYS DOC devices
32 * the BBT is searched and read but never created
34 * The auto generated bad block table is located in the last good blocks
35 * of the device. The table is mirrored, so it can be updated eventually.
36 * The table is marked in the OOB area with an ident pattern and a version
37 * number which indicates which of both tables is more up to date. If the NAND
38 * controller needs the complete OOB area for the ECC information then the
39 * option NAND_USE_FLASH_BBT_NO_OOB should be used: it moves the ident pattern
40 * and the version byte into the data area and the OOB area will remain
43 * The table uses 2 bits per block
45 * 00b: block is factory marked bad
46 * 01b, 10b: block is marked bad due to wear
48 * The memory bad block table uses the following scheme:
50 * 01b: block is marked bad due to wear
51 * 10b: block is reserved (to protect the bbt area)
52 * 11b: block is factory marked bad
54 * Multichip devices like DOC store the bad block info per floor.
56 * Following assumptions are made:
57 * - bbts start at a page boundary, if autolocated on a block boundary
58 * - the space necessary for a bbt in FLASH does not exceed a block boundary
64 #include <linux/mtd/compat.h>
65 #include <linux/mtd/mtd.h>
66 #include <linux/mtd/nand.h>
67 #include <linux/mtd/nand_ecc.h>
68 #include <linux/bitops.h>
70 #include <asm/errno.h>
72 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
76 ret = memcmp(buf, td->pattern, td->len);
83 * check_pattern - [GENERIC] check if a pattern is in the buffer
84 * @buf: the buffer to search
85 * @len: the length of buffer to search
86 * @paglen: the pagelength
87 * @td: search pattern descriptor
89 * Check for a pattern at the given place. Used to search bad block
90 * tables and good / bad block identifiers.
91 * If the SCAN_EMPTY option is set then check, if all bytes except the
92 * pattern area contain 0xff
95 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
100 if (td->options & NAND_BBT_NO_OOB)
101 return check_pattern_no_oob(buf, td);
103 end = paglen + td->offs;
104 if (td->options & NAND_BBT_SCANEMPTY) {
105 for (i = 0; i < end; i++) {
112 /* Compare the pattern */
113 for (i = 0; i < td->len; i++) {
114 if (p[i] != td->pattern[i])
118 /* Check both positions 1 and 6 for pattern? */
119 if (td->options & NAND_BBT_SCANBYTE1AND6) {
120 if (td->options & NAND_BBT_SCANEMPTY) {
122 end += NAND_SMALL_BADBLOCK_POS - td->offs;
123 /* Check region between positions 1 and 6 */
124 for (i = 0; i < NAND_SMALL_BADBLOCK_POS - td->offs - td->len;
131 p += NAND_SMALL_BADBLOCK_POS - td->offs;
133 /* Compare the pattern */
134 for (i = 0; i < td->len; i++) {
135 if (p[i] != td->pattern[i])
140 if (td->options & NAND_BBT_SCANEMPTY) {
143 for (i = end; i < len; i++) {
152 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
153 * @buf: the buffer to search
154 * @td: search pattern descriptor
156 * Check for a pattern at the given place. Used to search bad block
157 * tables and good / bad block identifiers. Same as check_pattern, but
158 * no optional empty check
161 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
166 /* Compare the pattern */
167 for (i = 0; i < td->len; i++) {
168 if (p[td->offs + i] != td->pattern[i])
171 /* Need to check location 1 AND 6? */
172 if (td->options & NAND_BBT_SCANBYTE1AND6) {
173 for (i = 0; i < td->len; i++) {
174 if (p[NAND_SMALL_BADBLOCK_POS + i] != td->pattern[i])
182 * add_marker_len - compute the length of the marker in data area
183 * @td: BBT descriptor used for computation
185 * The length will be 0 if the markeris located in OOB area.
187 static u32 add_marker_len(struct nand_bbt_descr *td)
191 if (!(td->options & NAND_BBT_NO_OOB))
195 if (td->options & NAND_BBT_VERSION)
201 * read_bbt - [GENERIC] Read the bad block table starting from page
202 * @mtd: MTD device structure
203 * @buf: temporary buffer
204 * @page: the starting page
205 * @num: the number of bbt descriptors to read
206 * @td: the bbt describtion table
207 * @offs: offset in the memory table
209 * Read the bad block table starting from page.
212 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
213 struct nand_bbt_descr *td, int offs)
215 int res, i, j, act = 0;
216 struct nand_chip *this = mtd->priv;
217 size_t retlen, len, totlen;
219 int bits = td->options & NAND_BBT_NRBITS_MSK;
220 uint8_t msk = (uint8_t) ((1 << bits) - 1);
222 int reserved_block_code = td->reserved_block_code;
224 totlen = (num * bits) >> 3;
225 marker_len = add_marker_len(td);
226 from = ((loff_t) page) << this->page_shift;
229 len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
232 * In case the BBT marker is not in the OOB area it
233 * will be just in the first page.
239 res = mtd->read(mtd, from, len, &retlen, buf);
242 printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
245 printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
249 for (i = 0; i < len; i++) {
250 uint8_t dat = buf[i];
251 for (j = 0; j < 8; j += bits, act += 2) {
252 uint8_t tmp = (dat >> j) & msk;
255 if (reserved_block_code && (tmp == reserved_block_code)) {
256 printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n",
257 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
258 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
259 mtd->ecc_stats.bbtblocks++;
262 /* Leave it for now, if its matured we can move this
263 * message to MTD_DEBUG_LEVEL0 */
264 printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n",
265 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
266 /* Factory marked bad or worn out ? */
268 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
270 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
271 mtd->ecc_stats.badblocks++;
281 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
282 * @mtd: MTD device structure
283 * @buf: temporary buffer
284 * @td: descriptor for the bad block table
285 * @chip: read the table for a specific chip, -1 read all chips.
286 * Applies only if NAND_BBT_PERCHIP option is set
288 * Read the bad block table for all chips starting at a given page
289 * We assume that the bbt bits are in consecutive order.
291 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
293 struct nand_chip *this = mtd->priv;
296 if (td->options & NAND_BBT_PERCHIP) {
298 for (i = 0; i < this->numchips; i++) {
299 if (chip == -1 || chip == i)
300 res = read_bbt(mtd, buf, td->pages[i],
301 this->chipsize >> this->bbt_erase_shift,
305 offs += this->chipsize >> (this->bbt_erase_shift + 2);
308 res = read_bbt(mtd, buf, td->pages[0],
309 mtd->size >> this->bbt_erase_shift, td, 0);
317 * BBT marker is in the first page, no OOB.
319 static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
320 struct nand_bbt_descr *td)
326 if (td->options & NAND_BBT_VERSION)
329 return mtd->read(mtd, offs, len, &retlen, buf);
333 * Scan read raw data from flash
335 static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
338 struct mtd_oob_ops ops;
341 ops.mode = MTD_OOB_RAW;
343 ops.ooblen = mtd->oobsize;
347 if (len <= mtd->writesize) {
348 ops.oobbuf = buf + len;
351 return mtd->read_oob(mtd, offs, &ops);
353 ops.oobbuf = buf + mtd->writesize;
355 ops.len = mtd->writesize;
356 res = mtd->read_oob(mtd, offs, &ops);
362 buf += mtd->oobsize + mtd->writesize;
363 len -= mtd->writesize;
368 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
369 size_t len, struct nand_bbt_descr *td)
371 if (td->options & NAND_BBT_NO_OOB)
372 return scan_read_raw_data(mtd, buf, offs, td);
374 return scan_read_raw_oob(mtd, buf, offs, len);
378 * Scan write data with oob to flash
380 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
381 uint8_t *buf, uint8_t *oob)
383 struct mtd_oob_ops ops;
385 ops.mode = MTD_OOB_PLACE;
387 ops.ooblen = mtd->oobsize;
392 return mtd->write_oob(mtd, offs, &ops);
395 static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
397 u32 ver_offs = td->veroffs;
399 if (!(td->options & NAND_BBT_NO_OOB))
400 ver_offs += mtd->writesize;
405 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
406 * @mtd: MTD device structure
407 * @buf: temporary buffer
408 * @td: descriptor for the bad block table
409 * @md: descriptor for the bad block table mirror
411 * Read the bad block table(s) for all chips starting at a given page
412 * We assume that the bbt bits are in consecutive order.
415 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
416 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
418 struct nand_chip *this = mtd->priv;
420 /* Read the primary version, if available */
421 if (td->options & NAND_BBT_VERSION) {
422 scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
424 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
425 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
426 td->pages[0], td->version[0]);
429 /* Read the mirror version, if available */
430 if (md && (md->options & NAND_BBT_VERSION)) {
431 scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
433 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
434 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
435 md->pages[0], md->version[0]);
441 * Scan a given block full
443 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
444 loff_t offs, uint8_t *buf, size_t readlen,
445 int scanlen, int len)
449 ret = scan_read_raw_oob(mtd, buf, offs, readlen);
453 for (j = 0; j < len; j++, buf += scanlen) {
454 if (check_pattern(buf, scanlen, mtd->writesize, bd))
461 * Scan a given block partially
463 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
464 loff_t offs, uint8_t *buf, int len)
466 struct mtd_oob_ops ops;
469 ops.ooblen = mtd->oobsize;
473 ops.mode = MTD_OOB_PLACE;
475 for (j = 0; j < len; j++) {
477 * Read the full oob until read_oob is fixed to
478 * handle single byte reads for 16 bit
481 ret = mtd->read_oob(mtd, offs, &ops);
485 if (check_short_pattern(buf, bd))
488 offs += mtd->writesize;
494 * create_bbt - [GENERIC] Create a bad block table by scanning the device
495 * @mtd: MTD device structure
496 * @buf: temporary buffer
497 * @bd: descriptor for the good/bad block search pattern
498 * @chip: create the table for a specific chip, -1 read all chips.
499 * Applies only if NAND_BBT_PERCHIP option is set
501 * Create a bad block table by scanning the device
502 * for the given good/bad block identify pattern
504 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
505 struct nand_bbt_descr *bd, int chip)
507 struct nand_chip *this = mtd->priv;
508 int i, numblocks, len, scanlen;
513 MTDDEBUG(MTD_DEBUG_LEVEL0, "Scanning device for bad blocks\n");
515 if (bd->options & NAND_BBT_SCANALLPAGES)
516 len = 1 << (this->bbt_erase_shift - this->page_shift);
517 else if (bd->options & NAND_BBT_SCAN2NDPAGE)
522 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
523 /* We need only read few bytes from the OOB area */
527 /* Full page content should be read */
528 scanlen = mtd->writesize + mtd->oobsize;
529 readlen = len * mtd->writesize;
533 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
534 * below as it makes shifting and masking less painful */
535 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
539 if (chip >= this->numchips) {
540 printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
541 chip + 1, this->numchips);
544 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
545 startblock = chip * numblocks;
546 numblocks += startblock;
547 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
550 if (this->options & NAND_BBT_SCANLASTPAGE)
551 from += mtd->erasesize - (mtd->writesize * len);
553 for (i = startblock; i < numblocks;) {
556 BUG_ON(bd->options & NAND_BBT_NO_OOB);
558 if (bd->options & NAND_BBT_SCANALLPAGES)
559 ret = scan_block_full(mtd, bd, from, buf, readlen,
562 ret = scan_block_fast(mtd, bd, from, buf, len);
568 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
569 MTDDEBUG(MTD_DEBUG_LEVEL0,
570 "Bad eraseblock %d at 0x%012llx\n",
571 i >> 1, (unsigned long long)from);
572 mtd->ecc_stats.badblocks++;
576 from += (1 << this->bbt_erase_shift);
582 * search_bbt - [GENERIC] scan the device for a specific bad block table
583 * @mtd: MTD device structure
584 * @buf: temporary buffer
585 * @td: descriptor for the bad block table
587 * Read the bad block table by searching for a given ident pattern.
588 * Search is preformed either from the beginning up or from the end of
589 * the device downwards. The search starts always at the start of a
591 * If the option NAND_BBT_PERCHIP is given, each chip is searched
592 * for a bbt, which contains the bad block information of this chip.
593 * This is necessary to provide support for certain DOC devices.
595 * The bbt ident pattern resides in the oob area of the first page
598 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
600 struct nand_chip *this = mtd->priv;
602 int startblock, block, dir;
603 int scanlen = mtd->writesize + mtd->oobsize;
605 int blocktopage = this->bbt_erase_shift - this->page_shift;
607 /* Search direction top -> down ? */
608 if (td->options & NAND_BBT_LASTBLOCK) {
609 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
616 /* Do we have a bbt per chip ? */
617 if (td->options & NAND_BBT_PERCHIP) {
618 chips = this->numchips;
619 bbtblocks = this->chipsize >> this->bbt_erase_shift;
620 startblock &= bbtblocks - 1;
623 bbtblocks = mtd->size >> this->bbt_erase_shift;
626 for (i = 0; i < chips; i++) {
627 /* Reset version information */
630 /* Scan the maximum number of blocks */
631 for (block = 0; block < td->maxblocks; block++) {
633 int actblock = startblock + dir * block;
634 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
636 /* Read first page */
637 scan_read_raw(mtd, buf, offs, mtd->writesize, td);
638 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
639 td->pages[i] = actblock << blocktopage;
640 if (td->options & NAND_BBT_VERSION) {
641 offs = bbt_get_ver_offs(mtd, td);
642 td->version[i] = buf[offs];
647 startblock += this->chipsize >> this->bbt_erase_shift;
649 /* Check, if we found a bbt for each requested chip */
650 for (i = 0; i < chips; i++) {
651 if (td->pages[i] == -1)
652 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
654 printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i],
661 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
662 * @mtd: MTD device structure
663 * @buf: temporary buffer
664 * @td: descriptor for the bad block table
665 * @md: descriptor for the bad block table mirror
667 * Search and read the bad block table(s)
669 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
671 /* Search the primary table */
672 search_bbt(mtd, buf, td);
674 /* Search the mirror table */
676 search_bbt(mtd, buf, md);
678 /* Force result check */
683 * write_bbt - [GENERIC] (Re)write the bad block table
685 * @mtd: MTD device structure
686 * @buf: temporary buffer
687 * @td: descriptor for the bad block table
688 * @md: descriptor for the bad block table mirror
689 * @chipsel: selector for a specific chip, -1 for all
691 * (Re)write the bad block table
694 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
695 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
698 struct nand_chip *this = mtd->priv;
699 struct erase_info einfo;
700 int i, j, res, chip = 0;
701 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
702 int nrchips, bbtoffs, pageoffs, ooboffs;
704 uint8_t rcode = td->reserved_block_code;
705 size_t retlen, len = 0;
707 struct mtd_oob_ops ops;
709 ops.ooblen = mtd->oobsize;
712 ops.mode = MTD_OOB_PLACE;
716 /* Write bad block table per chip rather than per device ? */
717 if (td->options & NAND_BBT_PERCHIP) {
718 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
719 /* Full device write or specific chip ? */
721 nrchips = this->numchips;
723 nrchips = chipsel + 1;
727 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
731 /* Loop through the chips */
732 for (; chip < nrchips; chip++) {
734 /* There was already a version of the table, reuse the page
735 * This applies for absolute placement too, as we have the
736 * page nr. in td->pages.
738 if (td->pages[chip] != -1) {
739 page = td->pages[chip];
743 /* Automatic placement of the bad block table */
744 /* Search direction top -> down ? */
745 if (td->options & NAND_BBT_LASTBLOCK) {
746 startblock = numblocks * (chip + 1) - 1;
749 startblock = chip * numblocks;
753 for (i = 0; i < td->maxblocks; i++) {
754 int block = startblock + dir * i;
755 /* Check, if the block is bad */
756 switch ((this->bbt[block >> 2] >>
757 (2 * (block & 0x03))) & 0x03) {
763 (this->bbt_erase_shift - this->page_shift);
764 /* Check, if the block is used by the mirror table */
765 if (!md || md->pages[chip] != page)
768 printk(KERN_ERR "No space left to write bad block table\n");
772 /* Set up shift count and masks for the flash table */
773 bits = td->options & NAND_BBT_NRBITS_MSK;
776 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
779 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
782 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
785 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
788 default: return -EINVAL;
791 bbtoffs = chip * (numblocks >> 2);
793 to = ((loff_t) page) << this->page_shift;
795 /* Must we save the block contents ? */
796 if (td->options & NAND_BBT_SAVECONTENT) {
797 /* Make it block aligned */
798 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
799 len = 1 << this->bbt_erase_shift;
800 res = mtd->read(mtd, to, len, &retlen, buf);
803 printk(KERN_INFO "nand_bbt: Error "
804 "reading block for writing "
805 "the bad block table\n");
808 printk(KERN_WARNING "nand_bbt: ECC error "
809 "while reading block for writing "
810 "bad block table\n");
813 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
814 ops.oobbuf = &buf[len];
815 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
816 if (res < 0 || ops.oobretlen != ops.ooblen)
819 /* Calc the byte offset in the buffer */
820 pageoffs = page - (int)(to >> this->page_shift);
821 offs = pageoffs << this->page_shift;
822 /* Preset the bbt area with 0xff */
823 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
824 ooboffs = len + (pageoffs * mtd->oobsize);
826 } else if (td->options & NAND_BBT_NO_OOB) {
829 /* the version byte */
830 if (td->options & NAND_BBT_VERSION)
833 len = (size_t) (numblocks >> sft);
835 /* Make it page aligned ! */
836 len = ALIGN(len, mtd->writesize);
837 /* Preset the buffer with 0xff */
838 memset(buf, 0xff, len);
839 /* Pattern is located at the begin of first page */
840 memcpy(buf, td->pattern, td->len);
843 len = (size_t) (numblocks >> sft);
844 /* Make it page aligned ! */
845 len = ALIGN(len, mtd->writesize);
846 /* Preset the buffer with 0xff */
847 memset(buf, 0xff, len +
848 (len >> this->page_shift)* mtd->oobsize);
851 /* Pattern is located in oob area of first page */
852 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
855 if (td->options & NAND_BBT_VERSION)
856 buf[ooboffs + td->veroffs] = td->version[chip];
858 /* walk through the memory table */
859 for (i = 0; i < numblocks;) {
861 dat = this->bbt[bbtoffs + (i >> 2)];
862 for (j = 0; j < 4; j++, i++) {
863 int sftcnt = (i << (3 - sft)) & sftmsk;
864 /* Do not store the reserved bbt blocks ! */
865 buf[offs + (i >> sft)] &=
866 ~(msk[dat & 0x03] << sftcnt);
871 memset(&einfo, 0, sizeof(einfo));
874 einfo.len = 1 << this->bbt_erase_shift;
875 res = nand_erase_nand(mtd, &einfo, 1);
879 res = scan_write_bbt(mtd, to, len, buf,
880 td->options & NAND_BBT_NO_OOB ? NULL :
885 printk(KERN_DEBUG "Bad block table written to 0x%012llx, version "
886 "0x%02X\n", (unsigned long long)to, td->version[chip]);
888 /* Mark it as used */
889 td->pages[chip] = page;
895 "nand_bbt: Error while writing bad block table %d\n", res);
900 * nand_memory_bbt - [GENERIC] create a memory based bad block table
901 * @mtd: MTD device structure
902 * @bd: descriptor for the good/bad block search pattern
904 * The function creates a memory based bbt by scanning the device
905 * for manufacturer / software marked good / bad blocks
907 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
909 struct nand_chip *this = mtd->priv;
911 bd->options &= ~NAND_BBT_SCANEMPTY;
912 return create_bbt(mtd, this->buffers->databuf, bd, -1);
916 * check_create - [GENERIC] create and write bbt(s) if necessary
917 * @mtd: MTD device structure
918 * @buf: temporary buffer
919 * @bd: descriptor for the good/bad block search pattern
921 * The function checks the results of the previous call to read_bbt
922 * and creates / updates the bbt(s) if necessary
923 * Creation is necessary if no bbt was found for the chip/device
924 * Update is necessary if one of the tables is missing or the
925 * version nr. of one table is less than the other
927 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
929 int i, chips, writeops, chipsel, res;
930 struct nand_chip *this = mtd->priv;
931 struct nand_bbt_descr *td = this->bbt_td;
932 struct nand_bbt_descr *md = this->bbt_md;
933 struct nand_bbt_descr *rd, *rd2;
935 /* Do we have a bbt per chip ? */
936 if (td->options & NAND_BBT_PERCHIP)
937 chips = this->numchips;
941 for (i = 0; i < chips; i++) {
945 /* Per chip or per device ? */
946 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
947 /* Mirrored table available ? */
949 if (td->pages[i] == -1 && md->pages[i] == -1) {
954 if (td->pages[i] == -1) {
956 td->version[i] = md->version[i];
961 if (md->pages[i] == -1) {
963 md->version[i] = td->version[i];
968 if (td->version[i] == md->version[i]) {
970 if (!(td->options & NAND_BBT_VERSION))
975 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
977 md->version[i] = td->version[i];
981 td->version[i] = md->version[i];
988 if (td->pages[i] == -1) {
996 /* Create the bad block table by scanning the device ? */
997 if (!(td->options & NAND_BBT_CREATE))
1000 /* Create the table in memory by scanning the chip(s) */
1001 if (!(this->options & NAND_CREATE_EMPTY_BBT))
1002 create_bbt(mtd, buf, bd, chipsel);
1008 /* read back first ? */
1010 read_abs_bbt(mtd, buf, rd, chipsel);
1011 /* If they weren't versioned, read both. */
1013 read_abs_bbt(mtd, buf, rd2, chipsel);
1015 /* Write the bad block table to the device ? */
1016 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1017 res = write_bbt(mtd, buf, td, md, chipsel);
1022 /* Write the mirror bad block table to the device ? */
1023 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1024 res = write_bbt(mtd, buf, md, td, chipsel);
1033 * mark_bbt_regions - [GENERIC] mark the bad block table regions
1034 * @mtd: MTD device structure
1035 * @td: bad block table descriptor
1037 * The bad block table regions are marked as "bad" to prevent
1038 * accidental erasures / writes. The regions are identified by
1041 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
1043 struct nand_chip *this = mtd->priv;
1044 int i, j, chips, block, nrblocks, update;
1045 uint8_t oldval, newval;
1047 /* Do we have a bbt per chip ? */
1048 if (td->options & NAND_BBT_PERCHIP) {
1049 chips = this->numchips;
1050 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
1053 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1056 for (i = 0; i < chips; i++) {
1057 if ((td->options & NAND_BBT_ABSPAGE) ||
1058 !(td->options & NAND_BBT_WRITE)) {
1059 if (td->pages[i] == -1)
1061 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1063 oldval = this->bbt[(block >> 3)];
1064 newval = oldval | (0x2 << (block & 0x06));
1065 this->bbt[(block >> 3)] = newval;
1066 if ((oldval != newval) && td->reserved_block_code)
1067 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
1071 if (td->options & NAND_BBT_LASTBLOCK)
1072 block = ((i + 1) * nrblocks) - td->maxblocks;
1074 block = i * nrblocks;
1076 for (j = 0; j < td->maxblocks; j++) {
1077 oldval = this->bbt[(block >> 3)];
1078 newval = oldval | (0x2 << (block & 0x06));
1079 this->bbt[(block >> 3)] = newval;
1080 if (oldval != newval)
1084 /* If we want reserved blocks to be recorded to flash, and some
1085 new ones have been marked, then we need to update the stored
1086 bbts. This should only happen once. */
1087 if (update && td->reserved_block_code)
1088 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
1093 * verify_bbt_descr - verify the bad block description
1094 * @mtd: MTD device structure
1095 * @bd: the table to verify
1097 * This functions performs a few sanity checks on the bad block description
1100 static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1102 struct nand_chip *this = mtd->priv;
1110 pattern_len = bd->len;
1111 bits = bd->options & NAND_BBT_NRBITS_MSK;
1113 BUG_ON((this->options & NAND_USE_FLASH_BBT_NO_OOB) &&
1114 !(this->options & NAND_USE_FLASH_BBT));
1117 if (bd->options & NAND_BBT_VERSION)
1120 if (bd->options & NAND_BBT_NO_OOB) {
1121 BUG_ON(!(this->options & NAND_USE_FLASH_BBT));
1122 BUG_ON(!(this->options & NAND_USE_FLASH_BBT_NO_OOB));
1124 if (bd->options & NAND_BBT_VERSION)
1125 BUG_ON(bd->veroffs != bd->len);
1126 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1129 if (bd->options & NAND_BBT_PERCHIP)
1130 table_size = this->chipsize >> this->bbt_erase_shift;
1132 table_size = mtd->size >> this->bbt_erase_shift;
1135 if (bd->options & NAND_BBT_NO_OOB)
1136 table_size += pattern_len;
1137 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1141 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1142 * @mtd: MTD device structure
1143 * @bd: descriptor for the good/bad block search pattern
1145 * The function checks, if a bad block table(s) is/are already
1146 * available. If not it scans the device for manufacturer
1147 * marked good / bad blocks and writes the bad block table(s) to
1148 * the selected place.
1150 * The bad block table memory is allocated here. It must be freed
1151 * by calling the nand_free_bbt function.
1154 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1156 struct nand_chip *this = mtd->priv;
1159 struct nand_bbt_descr *td = this->bbt_td;
1160 struct nand_bbt_descr *md = this->bbt_md;
1162 len = mtd->size >> (this->bbt_erase_shift + 2);
1163 /* Allocate memory (2bit per block) and clear the memory bad block table */
1164 this->bbt = kzalloc(len, GFP_KERNEL);
1166 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
1170 /* If no primary table decriptor is given, scan the device
1171 * to build a memory based bad block table
1174 if ((res = nand_memory_bbt(mtd, bd))) {
1175 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1181 verify_bbt_descr(mtd, td);
1182 verify_bbt_descr(mtd, md);
1184 /* Allocate a temporary buffer for one eraseblock incl. oob */
1185 len = (1 << this->bbt_erase_shift);
1186 len += (len >> this->page_shift) * mtd->oobsize;
1189 printk(KERN_ERR "nand_bbt: Out of memory\n");
1195 /* Is the bbt at a given page ? */
1196 if (td->options & NAND_BBT_ABSPAGE) {
1197 res = read_abs_bbts(mtd, buf, td, md);
1199 /* Search the bad block table using a pattern in oob */
1200 res = search_read_bbts(mtd, buf, td, md);
1204 res = check_create(mtd, buf, bd);
1206 /* Prevent the bbt regions from erasing / writing */
1207 mark_bbt_region(mtd, td);
1209 mark_bbt_region(mtd, md);
1216 * nand_update_bbt - [NAND Interface] update bad block table(s)
1217 * @mtd: MTD device structure
1218 * @offs: the offset of the newly marked block
1220 * The function updates the bad block table(s)
1222 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1224 struct nand_chip *this = mtd->priv;
1225 int len, res = 0, writeops = 0;
1228 struct nand_bbt_descr *td = this->bbt_td;
1229 struct nand_bbt_descr *md = this->bbt_md;
1231 if (!this->bbt || !td)
1234 /* Allocate a temporary buffer for one eraseblock incl. oob */
1235 len = (1 << this->bbt_erase_shift);
1236 len += (len >> this->page_shift) * mtd->oobsize;
1237 buf = kmalloc(len, GFP_KERNEL);
1239 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1243 writeops = md != NULL ? 0x03 : 0x01;
1245 /* Do we have a bbt per chip ? */
1246 if (td->options & NAND_BBT_PERCHIP) {
1247 chip = (int)(offs >> this->chip_shift);
1254 td->version[chip]++;
1256 md->version[chip]++;
1258 /* Write the bad block table to the device ? */
1259 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1260 res = write_bbt(mtd, buf, td, md, chipsel);
1264 /* Write the mirror bad block table to the device ? */
1265 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1266 res = write_bbt(mtd, buf, md, td, chipsel);
1274 /* Define some generic bad / good block scan pattern which are used
1275 * while scanning a device for factory marked good / bad blocks. */
1276 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1278 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1280 static struct nand_bbt_descr agand_flashbased = {
1281 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1284 .pattern = scan_agand_pattern
1287 /* Generic flash bbt decriptors
1289 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1290 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1292 static struct nand_bbt_descr bbt_main_descr = {
1293 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1294 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1299 .pattern = bbt_pattern
1302 static struct nand_bbt_descr bbt_mirror_descr = {
1303 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1304 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1309 .pattern = mirror_pattern
1312 static struct nand_bbt_descr bbt_main_no_bbt_descr = {
1313 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1314 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1319 .pattern = bbt_pattern
1322 static struct nand_bbt_descr bbt_mirror_no_bbt_descr = {
1323 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1324 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1329 .pattern = mirror_pattern
1332 #define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
1333 NAND_BBT_SCANBYTE1AND6)
1335 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1336 * @this: NAND chip to create descriptor for
1338 * This function allocates and initializes a nand_bbt_descr for BBM detection
1339 * based on the properties of "this". The new descriptor is stored in
1340 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1341 * passed to this function.
1344 static int nand_create_default_bbt_descr(struct nand_chip *this)
1346 struct nand_bbt_descr *bd;
1347 if (this->badblock_pattern) {
1348 printk(KERN_WARNING "BBT descr already allocated; not replacing.\n");
1351 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1353 printk(KERN_ERR "nand_create_default_bbt_descr: Out of memory\n");
1356 bd->options = this->options & BBT_SCAN_OPTIONS;
1357 bd->offs = this->badblockpos;
1358 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1359 bd->pattern = scan_ff_pattern;
1360 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1361 this->badblock_pattern = bd;
1366 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1367 * @mtd: MTD device structure
1369 * This function selects the default bad block table
1370 * support for the device and calls the nand_scan_bbt function
1373 int nand_default_bbt(struct mtd_info *mtd)
1375 struct nand_chip *this = mtd->priv;
1377 /* Default for AG-AND. We must use a flash based
1378 * bad block table as the devices have factory marked
1379 * _good_ blocks. Erasing those blocks leads to loss
1380 * of the good / bad information, so we _must_ store
1381 * this information in a good / bad table during
1384 if (this->options & NAND_IS_AND) {
1385 /* Use the default pattern descriptors */
1386 if (!this->bbt_td) {
1387 this->bbt_td = &bbt_main_descr;
1388 this->bbt_md = &bbt_mirror_descr;
1390 this->options |= NAND_USE_FLASH_BBT;
1391 return nand_scan_bbt(mtd, &agand_flashbased);
1394 /* Is a flash based bad block table requested ? */
1395 if (this->options & NAND_USE_FLASH_BBT) {
1396 /* Use the default pattern descriptors */
1397 if (!this->bbt_td) {
1398 if (this->options & NAND_USE_FLASH_BBT_NO_OOB) {
1399 this->bbt_td = &bbt_main_no_bbt_descr;
1400 this->bbt_md = &bbt_mirror_no_bbt_descr;
1402 this->bbt_td = &bbt_main_descr;
1403 this->bbt_md = &bbt_mirror_descr;
1407 this->bbt_td = NULL;
1408 this->bbt_md = NULL;
1411 if (!this->badblock_pattern)
1412 nand_create_default_bbt_descr(this);
1414 return nand_scan_bbt(mtd, this->badblock_pattern);
1418 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1419 * @mtd: MTD device structure
1420 * @offs: offset in the device
1421 * @allowbbt: allow access to bad block table region
1424 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1426 struct nand_chip *this = mtd->priv;
1430 /* Get block number * 2 */
1431 block = (int)(offs >> (this->bbt_erase_shift - 1));
1432 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1434 MTDDEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1435 (unsigned int)offs, block >> 1, res);
1443 return allowbbt ? 0 : 1;