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_BBT_USE_FLASH) 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27 * If one of the BBTs is out of date or does not exist it is (re)created.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_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
40 * course): it moves the ident pattern and the version byte into the data area
41 * and the OOB area will remain untouched.
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
62 #include <linux/slab.h>
63 #include <linux/types.h>
64 #include <linux/mtd/mtd.h>
65 #include <linux/mtd/nand.h>
66 #include <linux/mtd/nand_ecc.h>
67 #include <linux/bitops.h>
68 #include <linux/delay.h>
69 #include <linux/vmalloc.h>
71 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
75 ret = memcmp(buf, td->pattern, td->len);
82 * check_pattern - [GENERIC] check if a pattern is in the buffer
83 * @buf: the buffer to search
84 * @len: the length of buffer to search
85 * @paglen: the pagelength
86 * @td: search pattern descriptor
88 * Check for a pattern at the given place. Used to search bad block tables and
89 * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if
90 * all bytes except the pattern area contain 0xff.
92 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
97 if (td->options & NAND_BBT_NO_OOB)
98 return check_pattern_no_oob(buf, td);
100 end = paglen + td->offs;
101 if (td->options & NAND_BBT_SCANEMPTY) {
102 for (i = 0; i < end; i++) {
109 /* Compare the pattern */
110 for (i = 0; i < td->len; i++) {
111 if (p[i] != td->pattern[i])
115 if (td->options & NAND_BBT_SCANEMPTY) {
118 for (i = end; i < len; i++) {
127 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
128 * @buf: the buffer to search
129 * @td: search pattern descriptor
131 * Check for a pattern at the given place. Used to search bad block tables and
132 * good / bad block identifiers. Same as check_pattern, but no optional empty
135 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
140 /* Compare the pattern */
141 for (i = 0; i < td->len; i++) {
142 if (p[td->offs + i] != td->pattern[i])
149 * add_marker_len - compute the length of the marker in data area
150 * @td: BBT descriptor used for computation
152 * The length will be 0 if the marker is located in OOB area.
154 static u32 add_marker_len(struct nand_bbt_descr *td)
158 if (!(td->options & NAND_BBT_NO_OOB))
162 if (td->options & NAND_BBT_VERSION)
168 * read_bbt - [GENERIC] Read the bad block table starting from page
169 * @mtd: MTD device structure
170 * @buf: temporary buffer
171 * @page: the starting page
172 * @num: the number of bbt descriptors to read
173 * @td: the bbt describtion table
174 * @offs: offset in the memory table
176 * Read the bad block table starting from page.
178 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
179 struct nand_bbt_descr *td, int offs)
181 int res, i, j, act = 0;
182 struct nand_chip *this = mtd->priv;
183 size_t retlen, len, totlen;
185 int bits = td->options & NAND_BBT_NRBITS_MSK;
186 uint8_t msk = (uint8_t)((1 << bits) - 1);
188 int reserved_block_code = td->reserved_block_code;
190 totlen = (num * bits) >> 3;
191 marker_len = add_marker_len(td);
192 from = ((loff_t)page) << this->page_shift;
195 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
198 * In case the BBT marker is not in the OOB area it
199 * will be just in the first page.
205 res = mtd->read(mtd, from, len, &retlen, buf);
208 pr_info("nand_bbt: error reading bad block table\n");
211 pr_warn("nand_bbt: ECC error while reading bad block table\n");
215 for (i = 0; i < len; i++) {
216 uint8_t dat = buf[i];
217 for (j = 0; j < 8; j += bits, act += 2) {
218 uint8_t tmp = (dat >> j) & msk;
221 if (reserved_block_code && (tmp == reserved_block_code)) {
222 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
223 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
224 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
225 mtd->ecc_stats.bbtblocks++;
229 * Leave it for now, if it's matured we can
230 * move this message to pr_debug.
232 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
233 (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
234 /* Factory marked bad or worn out? */
236 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
238 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
239 mtd->ecc_stats.badblocks++;
249 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
250 * @mtd: MTD device structure
251 * @buf: temporary buffer
252 * @td: descriptor for the bad block table
253 * @chip: read the table for a specific chip, -1 read all chips; applies only if
254 * NAND_BBT_PERCHIP option is set
256 * Read the bad block table for all chips starting at a given page. We assume
257 * that the bbt bits are in consecutive order.
259 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
261 struct nand_chip *this = mtd->priv;
264 if (td->options & NAND_BBT_PERCHIP) {
266 for (i = 0; i < this->numchips; i++) {
267 if (chip == -1 || chip == i)
268 res = read_bbt(mtd, buf, td->pages[i],
269 this->chipsize >> this->bbt_erase_shift,
273 offs += this->chipsize >> (this->bbt_erase_shift + 2);
276 res = read_bbt(mtd, buf, td->pages[0],
277 mtd->size >> this->bbt_erase_shift, td, 0);
284 /* BBT marker is in the first page, no OOB */
285 static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
286 struct nand_bbt_descr *td)
292 if (td->options & NAND_BBT_VERSION)
295 return mtd->read(mtd, offs, len, &retlen, buf);
298 /* Scan read raw data from flash */
299 static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
302 struct mtd_oob_ops ops;
305 ops.mode = MTD_OPS_RAW;
307 ops.ooblen = mtd->oobsize;
311 ops.len = min(len, (size_t)mtd->writesize);
312 ops.oobbuf = buf + ops.len;
314 res = mtd->read_oob(mtd, offs, &ops);
319 buf += mtd->oobsize + mtd->writesize;
320 len -= mtd->writesize;
325 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
326 size_t len, struct nand_bbt_descr *td)
328 if (td->options & NAND_BBT_NO_OOB)
329 return scan_read_raw_data(mtd, buf, offs, td);
331 return scan_read_raw_oob(mtd, buf, offs, len);
334 /* Scan write data with oob to flash */
335 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
336 uint8_t *buf, uint8_t *oob)
338 struct mtd_oob_ops ops;
340 ops.mode = MTD_OPS_PLACE_OOB;
342 ops.ooblen = mtd->oobsize;
347 return mtd->write_oob(mtd, offs, &ops);
350 static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
352 u32 ver_offs = td->veroffs;
354 if (!(td->options & NAND_BBT_NO_OOB))
355 ver_offs += mtd->writesize;
360 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
361 * @mtd: MTD device structure
362 * @buf: temporary buffer
363 * @td: descriptor for the bad block table
364 * @md: descriptor for the bad block table mirror
366 * Read the bad block table(s) for all chips starting at a given page. We
367 * assume that the bbt bits are in consecutive order.
369 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
370 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
372 struct nand_chip *this = mtd->priv;
374 /* Read the primary version, if available */
375 if (td->options & NAND_BBT_VERSION) {
376 scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
378 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
379 pr_info("Bad block table at page %d, version 0x%02X\n",
380 td->pages[0], td->version[0]);
383 /* Read the mirror version, if available */
384 if (md && (md->options & NAND_BBT_VERSION)) {
385 scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
387 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
388 pr_info("Bad block table at page %d, version 0x%02X\n",
389 md->pages[0], md->version[0]);
394 /* Scan a given block full */
395 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
396 loff_t offs, uint8_t *buf, size_t readlen,
397 int scanlen, int len)
401 ret = scan_read_raw_oob(mtd, buf, offs, readlen);
402 /* Ignore ECC errors when checking for BBM */
403 if (ret && ret != -EUCLEAN && ret != -EBADMSG)
406 for (j = 0; j < len; j++, buf += scanlen) {
407 if (check_pattern(buf, scanlen, mtd->writesize, bd))
413 /* Scan a given block partially */
414 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
415 loff_t offs, uint8_t *buf, int len)
417 struct mtd_oob_ops ops;
420 ops.ooblen = mtd->oobsize;
424 ops.mode = MTD_OPS_PLACE_OOB;
426 for (j = 0; j < len; j++) {
428 * Read the full oob until read_oob is fixed to handle single
429 * byte reads for 16 bit buswidth.
431 ret = mtd->read_oob(mtd, offs, &ops);
432 /* Ignore ECC errors when checking for BBM */
433 if (ret && ret != -EUCLEAN && ret != -EBADMSG)
436 if (check_short_pattern(buf, bd))
439 offs += mtd->writesize;
445 * create_bbt - [GENERIC] Create a bad block table by scanning the device
446 * @mtd: MTD device structure
447 * @buf: temporary buffer
448 * @bd: descriptor for the good/bad block search pattern
449 * @chip: create the table for a specific chip, -1 read all chips; applies only
450 * if NAND_BBT_PERCHIP option is set
452 * Create a bad block table by scanning the device for the given good/bad block
455 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
456 struct nand_bbt_descr *bd, int chip)
458 struct nand_chip *this = mtd->priv;
459 int i, numblocks, len, scanlen;
464 pr_info("Scanning device for bad blocks\n");
466 if (bd->options & NAND_BBT_SCANALLPAGES)
467 len = 1 << (this->bbt_erase_shift - this->page_shift);
468 else if (bd->options & NAND_BBT_SCAN2NDPAGE)
473 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
474 /* We need only read few bytes from the OOB area */
478 /* Full page content should be read */
479 scanlen = mtd->writesize + mtd->oobsize;
480 readlen = len * mtd->writesize;
485 * Note that numblocks is 2 * (real numblocks) here, see i+=2
486 * below as it makes shifting and masking less painful
488 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
492 if (chip >= this->numchips) {
493 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
494 chip + 1, this->numchips);
497 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
498 startblock = chip * numblocks;
499 numblocks += startblock;
500 from = (loff_t)startblock << (this->bbt_erase_shift - 1);
503 if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
504 from += mtd->erasesize - (mtd->writesize * len);
506 for (i = startblock; i < numblocks;) {
509 BUG_ON(bd->options & NAND_BBT_NO_OOB);
511 if (bd->options & NAND_BBT_SCANALLPAGES)
512 ret = scan_block_full(mtd, bd, from, buf, readlen,
515 ret = scan_block_fast(mtd, bd, from, buf, len);
521 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
522 pr_warn("Bad eraseblock %d at 0x%012llx\n",
523 i >> 1, (unsigned long long)from);
524 mtd->ecc_stats.badblocks++;
528 from += (1 << this->bbt_erase_shift);
534 * search_bbt - [GENERIC] scan the device for a specific bad block table
535 * @mtd: MTD device structure
536 * @buf: temporary buffer
537 * @td: descriptor for the bad block table
539 * Read the bad block table by searching for a given ident pattern. Search is
540 * preformed either from the beginning up or from the end of the device
541 * downwards. The search starts always at the start of a block. If the option
542 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
543 * the bad block information of this chip. This is necessary to provide support
544 * for certain DOC devices.
546 * The bbt ident pattern resides in the oob area of the first page in a block.
548 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
550 struct nand_chip *this = mtd->priv;
552 int bits, startblock, block, dir;
553 int scanlen = mtd->writesize + mtd->oobsize;
555 int blocktopage = this->bbt_erase_shift - this->page_shift;
557 /* Search direction top -> down? */
558 if (td->options & NAND_BBT_LASTBLOCK) {
559 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
566 /* Do we have a bbt per chip? */
567 if (td->options & NAND_BBT_PERCHIP) {
568 chips = this->numchips;
569 bbtblocks = this->chipsize >> this->bbt_erase_shift;
570 startblock &= bbtblocks - 1;
573 bbtblocks = mtd->size >> this->bbt_erase_shift;
576 /* Number of bits for each erase block in the bbt */
577 bits = td->options & NAND_BBT_NRBITS_MSK;
579 for (i = 0; i < chips; i++) {
580 /* Reset version information */
583 /* Scan the maximum number of blocks */
584 for (block = 0; block < td->maxblocks; block++) {
586 int actblock = startblock + dir * block;
587 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
589 /* Read first page */
590 scan_read_raw(mtd, buf, offs, mtd->writesize, td);
591 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
592 td->pages[i] = actblock << blocktopage;
593 if (td->options & NAND_BBT_VERSION) {
594 offs = bbt_get_ver_offs(mtd, td);
595 td->version[i] = buf[offs];
600 startblock += this->chipsize >> this->bbt_erase_shift;
602 /* Check, if we found a bbt for each requested chip */
603 for (i = 0; i < chips; i++) {
604 if (td->pages[i] == -1)
605 pr_warn("Bad block table not found for chip %d\n", i);
607 pr_info("Bad block table found at page %d, version "
608 "0x%02X\n", td->pages[i], td->version[i]);
614 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
615 * @mtd: MTD device structure
616 * @buf: temporary buffer
617 * @td: descriptor for the bad block table
618 * @md: descriptor for the bad block table mirror
620 * Search and read the bad block table(s).
622 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
624 /* Search the primary table */
625 search_bbt(mtd, buf, td);
627 /* Search the mirror table */
629 search_bbt(mtd, buf, md);
631 /* Force result check */
636 * write_bbt - [GENERIC] (Re)write the bad block table
637 * @mtd: MTD device structure
638 * @buf: temporary buffer
639 * @td: descriptor for the bad block table
640 * @md: descriptor for the bad block table mirror
641 * @chipsel: selector for a specific chip, -1 for all
643 * (Re)write the bad block table.
645 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
646 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
649 struct nand_chip *this = mtd->priv;
650 struct erase_info einfo;
651 int i, j, res, chip = 0;
652 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
653 int nrchips, bbtoffs, pageoffs, ooboffs;
655 uint8_t rcode = td->reserved_block_code;
656 size_t retlen, len = 0;
658 struct mtd_oob_ops ops;
660 ops.ooblen = mtd->oobsize;
663 ops.mode = MTD_OPS_PLACE_OOB;
667 /* Write bad block table per chip rather than per device? */
668 if (td->options & NAND_BBT_PERCHIP) {
669 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
670 /* Full device write or specific chip? */
672 nrchips = this->numchips;
674 nrchips = chipsel + 1;
678 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
682 /* Loop through the chips */
683 for (; chip < nrchips; chip++) {
685 * There was already a version of the table, reuse the page
686 * This applies for absolute placement too, as we have the
687 * page nr. in td->pages.
689 if (td->pages[chip] != -1) {
690 page = td->pages[chip];
695 * Automatic placement of the bad block table. Search direction
698 if (td->options & NAND_BBT_LASTBLOCK) {
699 startblock = numblocks * (chip + 1) - 1;
702 startblock = chip * numblocks;
706 for (i = 0; i < td->maxblocks; i++) {
707 int block = startblock + dir * i;
708 /* Check, if the block is bad */
709 switch ((this->bbt[block >> 2] >>
710 (2 * (block & 0x03))) & 0x03) {
716 (this->bbt_erase_shift - this->page_shift);
717 /* Check, if the block is used by the mirror table */
718 if (!md || md->pages[chip] != page)
721 pr_err("No space left to write bad block table\n");
725 /* Set up shift count and masks for the flash table */
726 bits = td->options & NAND_BBT_NRBITS_MSK;
729 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
732 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
735 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
738 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
741 default: return -EINVAL;
744 bbtoffs = chip * (numblocks >> 2);
746 to = ((loff_t)page) << this->page_shift;
748 /* Must we save the block contents? */
749 if (td->options & NAND_BBT_SAVECONTENT) {
750 /* Make it block aligned */
751 to &= ~((loff_t)((1 << this->bbt_erase_shift) - 1));
752 len = 1 << this->bbt_erase_shift;
753 res = mtd->read(mtd, to, len, &retlen, buf);
756 pr_info("nand_bbt: error reading block "
757 "for writing the bad block table\n");
760 pr_warn("nand_bbt: ECC error while reading "
761 "block for writing bad block table\n");
764 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
765 ops.oobbuf = &buf[len];
766 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
767 if (res < 0 || ops.oobretlen != ops.ooblen)
770 /* Calc the byte offset in the buffer */
771 pageoffs = page - (int)(to >> this->page_shift);
772 offs = pageoffs << this->page_shift;
773 /* Preset the bbt area with 0xff */
774 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
775 ooboffs = len + (pageoffs * mtd->oobsize);
777 } else if (td->options & NAND_BBT_NO_OOB) {
780 /* The version byte */
781 if (td->options & NAND_BBT_VERSION)
784 len = (size_t)(numblocks >> sft);
786 /* Make it page aligned! */
787 len = ALIGN(len, mtd->writesize);
788 /* Preset the buffer with 0xff */
789 memset(buf, 0xff, len);
790 /* Pattern is located at the begin of first page */
791 memcpy(buf, td->pattern, td->len);
794 len = (size_t)(numblocks >> sft);
795 /* Make it page aligned! */
796 len = ALIGN(len, mtd->writesize);
797 /* Preset the buffer with 0xff */
798 memset(buf, 0xff, len +
799 (len >> this->page_shift)* mtd->oobsize);
802 /* Pattern is located in oob area of first page */
803 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
806 if (td->options & NAND_BBT_VERSION)
807 buf[ooboffs + td->veroffs] = td->version[chip];
809 /* Walk through the memory table */
810 for (i = 0; i < numblocks;) {
812 dat = this->bbt[bbtoffs + (i >> 2)];
813 for (j = 0; j < 4; j++, i++) {
814 int sftcnt = (i << (3 - sft)) & sftmsk;
815 /* Do not store the reserved bbt blocks! */
816 buf[offs + (i >> sft)] &=
817 ~(msk[dat & 0x03] << sftcnt);
822 memset(&einfo, 0, sizeof(einfo));
825 einfo.len = 1 << this->bbt_erase_shift;
826 res = nand_erase_nand(mtd, &einfo, 1);
830 res = scan_write_bbt(mtd, to, len, buf,
831 td->options & NAND_BBT_NO_OOB ? NULL :
836 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
837 (unsigned long long)to, td->version[chip]);
839 /* Mark it as used */
840 td->pages[chip] = page;
845 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
850 * nand_memory_bbt - [GENERIC] create a memory based bad block table
851 * @mtd: MTD device structure
852 * @bd: descriptor for the good/bad block search pattern
854 * The function creates a memory based bbt by scanning the device for
855 * manufacturer / software marked good / bad blocks.
857 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
859 struct nand_chip *this = mtd->priv;
861 bd->options &= ~NAND_BBT_SCANEMPTY;
862 return create_bbt(mtd, this->buffers->databuf, bd, -1);
866 * check_create - [GENERIC] create and write bbt(s) if necessary
867 * @mtd: MTD device structure
868 * @buf: temporary buffer
869 * @bd: descriptor for the good/bad block search pattern
871 * The function checks the results of the previous call to read_bbt and creates
872 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
873 * for the chip/device. Update is necessary if one of the tables is missing or
874 * the version nr. of one table is less than the other.
876 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
878 int i, chips, writeops, chipsel, res;
879 struct nand_chip *this = mtd->priv;
880 struct nand_bbt_descr *td = this->bbt_td;
881 struct nand_bbt_descr *md = this->bbt_md;
882 struct nand_bbt_descr *rd, *rd2;
884 /* Do we have a bbt per chip? */
885 if (td->options & NAND_BBT_PERCHIP)
886 chips = this->numchips;
890 for (i = 0; i < chips; i++) {
894 /* Per chip or per device? */
895 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
896 /* Mirrored table available? */
898 if (td->pages[i] == -1 && md->pages[i] == -1) {
903 if (td->pages[i] == -1) {
905 td->version[i] = md->version[i];
910 if (md->pages[i] == -1) {
912 md->version[i] = td->version[i];
917 if (td->version[i] == md->version[i]) {
919 if (!(td->options & NAND_BBT_VERSION))
924 if (((int8_t)(td->version[i] - md->version[i])) > 0) {
926 md->version[i] = td->version[i];
930 td->version[i] = md->version[i];
937 if (td->pages[i] == -1) {
945 /* Create the bad block table by scanning the device? */
946 if (!(td->options & NAND_BBT_CREATE))
949 /* Create the table in memory by scanning the chip(s) */
950 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
951 create_bbt(mtd, buf, bd, chipsel);
957 /* Read back first? */
959 read_abs_bbt(mtd, buf, rd, chipsel);
960 /* If they weren't versioned, read both */
962 read_abs_bbt(mtd, buf, rd2, chipsel);
964 /* Write the bad block table to the device? */
965 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
966 res = write_bbt(mtd, buf, td, md, chipsel);
971 /* Write the mirror bad block table to the device? */
972 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
973 res = write_bbt(mtd, buf, md, td, chipsel);
982 * mark_bbt_regions - [GENERIC] mark the bad block table regions
983 * @mtd: MTD device structure
984 * @td: bad block table descriptor
986 * The bad block table regions are marked as "bad" to prevent accidental
987 * erasures / writes. The regions are identified by the mark 0x02.
989 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
991 struct nand_chip *this = mtd->priv;
992 int i, j, chips, block, nrblocks, update;
993 uint8_t oldval, newval;
995 /* Do we have a bbt per chip? */
996 if (td->options & NAND_BBT_PERCHIP) {
997 chips = this->numchips;
998 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
1001 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1004 for (i = 0; i < chips; i++) {
1005 if ((td->options & NAND_BBT_ABSPAGE) ||
1006 !(td->options & NAND_BBT_WRITE)) {
1007 if (td->pages[i] == -1)
1009 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1011 oldval = this->bbt[(block >> 3)];
1012 newval = oldval | (0x2 << (block & 0x06));
1013 this->bbt[(block >> 3)] = newval;
1014 if ((oldval != newval) && td->reserved_block_code)
1015 nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1));
1019 if (td->options & NAND_BBT_LASTBLOCK)
1020 block = ((i + 1) * nrblocks) - td->maxblocks;
1022 block = i * nrblocks;
1024 for (j = 0; j < td->maxblocks; j++) {
1025 oldval = this->bbt[(block >> 3)];
1026 newval = oldval | (0x2 << (block & 0x06));
1027 this->bbt[(block >> 3)] = newval;
1028 if (oldval != newval)
1033 * If we want reserved blocks to be recorded to flash, and some
1034 * new ones have been marked, then we need to update the stored
1035 * bbts. This should only happen once.
1037 if (update && td->reserved_block_code)
1038 nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1));
1043 * verify_bbt_descr - verify the bad block description
1044 * @mtd: MTD device structure
1045 * @bd: the table to verify
1047 * This functions performs a few sanity checks on the bad block description
1050 static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1052 struct nand_chip *this = mtd->priv;
1060 pattern_len = bd->len;
1061 bits = bd->options & NAND_BBT_NRBITS_MSK;
1063 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1064 !(this->bbt_options & NAND_BBT_USE_FLASH));
1067 if (bd->options & NAND_BBT_VERSION)
1070 if (bd->options & NAND_BBT_NO_OOB) {
1071 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1072 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1074 if (bd->options & NAND_BBT_VERSION)
1075 BUG_ON(bd->veroffs != bd->len);
1076 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1079 if (bd->options & NAND_BBT_PERCHIP)
1080 table_size = this->chipsize >> this->bbt_erase_shift;
1082 table_size = mtd->size >> this->bbt_erase_shift;
1085 if (bd->options & NAND_BBT_NO_OOB)
1086 table_size += pattern_len;
1087 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1091 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1092 * @mtd: MTD device structure
1093 * @bd: descriptor for the good/bad block search pattern
1095 * The function checks, if a bad block table(s) is/are already available. If
1096 * not it scans the device for manufacturer marked good / bad blocks and writes
1097 * the bad block table(s) to the selected place.
1099 * The bad block table memory is allocated here. It must be freed by calling
1100 * the nand_free_bbt function.
1102 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1104 struct nand_chip *this = mtd->priv;
1107 struct nand_bbt_descr *td = this->bbt_td;
1108 struct nand_bbt_descr *md = this->bbt_md;
1110 len = mtd->size >> (this->bbt_erase_shift + 2);
1112 * Allocate memory (2bit per block) and clear the memory bad block
1115 this->bbt = kzalloc(len, GFP_KERNEL);
1120 * If no primary table decriptor is given, scan the device to build a
1121 * memory based bad block table.
1124 if ((res = nand_memory_bbt(mtd, bd))) {
1125 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1131 verify_bbt_descr(mtd, td);
1132 verify_bbt_descr(mtd, md);
1134 /* Allocate a temporary buffer for one eraseblock incl. oob */
1135 len = (1 << this->bbt_erase_shift);
1136 len += (len >> this->page_shift) * mtd->oobsize;
1144 /* Is the bbt at a given page? */
1145 if (td->options & NAND_BBT_ABSPAGE) {
1146 res = read_abs_bbts(mtd, buf, td, md);
1148 /* Search the bad block table using a pattern in oob */
1149 res = search_read_bbts(mtd, buf, td, md);
1153 res = check_create(mtd, buf, bd);
1155 /* Prevent the bbt regions from erasing / writing */
1156 mark_bbt_region(mtd, td);
1158 mark_bbt_region(mtd, md);
1165 * nand_update_bbt - [NAND Interface] update bad block table(s)
1166 * @mtd: MTD device structure
1167 * @offs: the offset of the newly marked block
1169 * The function updates the bad block table(s).
1171 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1173 struct nand_chip *this = mtd->priv;
1177 struct nand_bbt_descr *td = this->bbt_td;
1178 struct nand_bbt_descr *md = this->bbt_md;
1180 if (!this->bbt || !td)
1183 /* Allocate a temporary buffer for one eraseblock incl. oob */
1184 len = (1 << this->bbt_erase_shift);
1185 len += (len >> this->page_shift) * mtd->oobsize;
1186 buf = kmalloc(len, GFP_KERNEL);
1190 /* Do we have a bbt per chip? */
1191 if (td->options & NAND_BBT_PERCHIP) {
1192 chip = (int)(offs >> this->chip_shift);
1199 td->version[chip]++;
1201 md->version[chip]++;
1203 /* Write the bad block table to the device? */
1204 if (td->options & NAND_BBT_WRITE) {
1205 res = write_bbt(mtd, buf, td, md, chipsel);
1209 /* Write the mirror bad block table to the device? */
1210 if (md && (md->options & NAND_BBT_WRITE)) {
1211 res = write_bbt(mtd, buf, md, td, chipsel);
1220 * Define some generic bad / good block scan pattern which are used
1221 * while scanning a device for factory marked good / bad blocks.
1223 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1225 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1227 static struct nand_bbt_descr agand_flashbased = {
1228 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1231 .pattern = scan_agand_pattern
1234 /* Generic flash bbt descriptors */
1235 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1236 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1238 static struct nand_bbt_descr bbt_main_descr = {
1239 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1240 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1245 .pattern = bbt_pattern
1248 static struct nand_bbt_descr bbt_mirror_descr = {
1249 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1250 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1255 .pattern = mirror_pattern
1258 static struct nand_bbt_descr bbt_main_no_bbt_descr = {
1259 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1260 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1265 .pattern = bbt_pattern
1268 static struct nand_bbt_descr bbt_mirror_no_bbt_descr = {
1269 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1270 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1275 .pattern = mirror_pattern
1279 * nand_create_default_bbt_descr - [INTERN] Creates a BBT descriptor structure
1280 * @this: NAND chip to create descriptor for
1282 * This function allocates and initializes a nand_bbt_descr for BBM detection
1283 * based on the properties of "this". The new descriptor is stored in
1284 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1285 * passed to this function.
1287 static int nand_create_default_bbt_descr(struct nand_chip *this)
1289 struct nand_bbt_descr *bd;
1290 if (this->badblock_pattern) {
1291 pr_warn("BBT descr already allocated; not replacing\n");
1294 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1297 bd->options = this->bbt_options;
1298 bd->offs = this->badblockpos;
1299 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1300 bd->pattern = scan_ff_pattern;
1301 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1302 this->badblock_pattern = bd;
1307 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1308 * @mtd: MTD device structure
1310 * This function selects the default bad block table support for the device and
1311 * calls the nand_scan_bbt function.
1313 int nand_default_bbt(struct mtd_info *mtd)
1315 struct nand_chip *this = mtd->priv;
1318 * Default for AG-AND. We must use a flash based bad block table as the
1319 * devices have factory marked _good_ blocks. Erasing those blocks
1320 * leads to loss of the good / bad information, so we _must_ store this
1321 * information in a good / bad table during startup.
1323 if (this->options & NAND_IS_AND) {
1324 /* Use the default pattern descriptors */
1325 if (!this->bbt_td) {
1326 this->bbt_td = &bbt_main_descr;
1327 this->bbt_md = &bbt_mirror_descr;
1329 this->bbt_options |= NAND_BBT_USE_FLASH;
1330 return nand_scan_bbt(mtd, &agand_flashbased);
1333 /* Is a flash based bad block table requested? */
1334 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1335 /* Use the default pattern descriptors */
1336 if (!this->bbt_td) {
1337 if (this->bbt_options & NAND_BBT_NO_OOB) {
1338 this->bbt_td = &bbt_main_no_bbt_descr;
1339 this->bbt_md = &bbt_mirror_no_bbt_descr;
1341 this->bbt_td = &bbt_main_descr;
1342 this->bbt_md = &bbt_mirror_descr;
1346 this->bbt_td = NULL;
1347 this->bbt_md = NULL;
1350 if (!this->badblock_pattern)
1351 nand_create_default_bbt_descr(this);
1353 return nand_scan_bbt(mtd, this->badblock_pattern);
1357 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1358 * @mtd: MTD device structure
1359 * @offs: offset in the device
1360 * @allowbbt: allow access to bad block table region
1362 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1364 struct nand_chip *this = mtd->priv;
1368 /* Get block number * 2 */
1369 block = (int)(offs >> (this->bbt_erase_shift - 1));
1370 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1372 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: "
1373 "(block %d) 0x%02x\n",
1374 (unsigned int)offs, block >> 1, res);
1382 return allowbbt ? 0 : 1;
1387 EXPORT_SYMBOL(nand_scan_bbt);
1388 EXPORT_SYMBOL(nand_default_bbt);