1 // SPDX-License-Identifier: GPL-2.0-only
4 * Bad block table support for the NAND driver
6 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
10 * When nand_scan_bbt is called, then it tries to find the bad block table
11 * depending on the options in the BBT descriptor(s). If no flash based BBT
12 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
13 * marked good / bad blocks. This information is used to create a memory BBT.
14 * Once a new bad block is discovered then the "factory" information is updated
16 * If a flash based BBT is specified then the function first tries to find the
17 * BBT on flash. If a BBT is found then the contents are read and the memory
18 * based BBT is created. If a mirrored BBT is selected then the mirror is
19 * searched too and the versions are compared. If the mirror has a greater
20 * version number, then 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22 * If one of the BBTs is out of date or does not exist it is (re)created.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 auto generated 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. If the NAND
33 * controller needs the complete OOB area for the ECC information then the
34 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
35 * course): it moves the ident pattern and the version byte into the data area
36 * and the OOB area will remain untouched.
38 * The table uses 2 bits per block
40 * 00b: block is factory marked bad
41 * 01b, 10b: block is marked bad due to wear
43 * The memory bad block table uses the following scheme:
45 * 01b: block is marked bad due to wear
46 * 10b: block is reserved (to protect the bbt area)
47 * 11b: block is factory marked bad
49 * Multichip devices like DOC store the bad block info per floor.
51 * Following assumptions are made:
52 * - bbts start at a page boundary, if autolocated on a block boundary
53 * - the space necessary for a bbt in FLASH does not exceed a block boundary
56 #include <linux/slab.h>
57 #include <linux/types.h>
58 #include <linux/mtd/mtd.h>
59 #include <linux/mtd/bbm.h>
60 #include <linux/bitops.h>
61 #include <linux/delay.h>
62 #include <linux/vmalloc.h>
63 #include <linux/export.h>
64 #include <linux/string.h>
66 #include "internals.h"
68 #define BBT_BLOCK_GOOD 0x00
69 #define BBT_BLOCK_WORN 0x01
70 #define BBT_BLOCK_RESERVED 0x02
71 #define BBT_BLOCK_FACTORY_BAD 0x03
73 #define BBT_ENTRY_MASK 0x03
74 #define BBT_ENTRY_SHIFT 2
76 static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)
78 uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];
79 entry >>= (block & BBT_ENTRY_MASK) * 2;
80 return entry & BBT_ENTRY_MASK;
83 static inline void bbt_mark_entry(struct nand_chip *chip, int block,
86 uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
87 chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
90 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
92 if (memcmp(buf, td->pattern, td->len))
98 * check_pattern - [GENERIC] check if a pattern is in the buffer
99 * @buf: the buffer to search
100 * @len: the length of buffer to search
101 * @paglen: the pagelength
102 * @td: search pattern descriptor
104 * Check for a pattern at the given place. Used to search bad block tables and
105 * good / bad block identifiers.
107 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
109 if (td->options & NAND_BBT_NO_OOB)
110 return check_pattern_no_oob(buf, td);
112 /* Compare the pattern */
113 if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
120 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
121 * @buf: the buffer to search
122 * @td: search pattern descriptor
124 * Check for a pattern at the given place. Used to search bad block tables and
125 * good / bad block identifiers. Same as check_pattern, but no optional empty
128 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
130 /* Compare the pattern */
131 if (memcmp(buf + td->offs, td->pattern, td->len))
137 * add_marker_len - compute the length of the marker in data area
138 * @td: BBT descriptor used for computation
140 * The length will be 0 if the marker is located in OOB area.
142 static u32 add_marker_len(struct nand_bbt_descr *td)
146 if (!(td->options & NAND_BBT_NO_OOB))
150 if (td->options & NAND_BBT_VERSION)
156 * read_bbt - [GENERIC] Read the bad block table starting from page
157 * @this: NAND chip object
158 * @buf: temporary buffer
159 * @page: the starting page
160 * @num: the number of bbt descriptors to read
161 * @td: the bbt describtion table
162 * @offs: block number offset in the table
164 * Read the bad block table starting from page.
166 static int read_bbt(struct nand_chip *this, uint8_t *buf, int page, int num,
167 struct nand_bbt_descr *td, int offs)
169 struct mtd_info *mtd = nand_to_mtd(this);
170 int res, ret = 0, i, j, act = 0;
171 size_t retlen, len, totlen;
173 int bits = td->options & NAND_BBT_NRBITS_MSK;
174 uint8_t msk = (uint8_t)((1 << bits) - 1);
176 int reserved_block_code = td->reserved_block_code;
178 totlen = (num * bits) >> 3;
179 marker_len = add_marker_len(td);
180 from = ((loff_t)page) << this->page_shift;
183 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
186 * In case the BBT marker is not in the OOB area it
187 * will be just in the first page.
193 res = mtd_read(mtd, from, len, &retlen, buf);
195 if (mtd_is_eccerr(res)) {
196 pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
197 from & ~mtd->writesize);
199 } else if (mtd_is_bitflip(res)) {
200 pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
201 from & ~mtd->writesize);
204 pr_info("nand_bbt: error reading BBT\n");
210 for (i = 0; i < len; i++) {
211 uint8_t dat = buf[i];
212 for (j = 0; j < 8; j += bits, act++) {
213 uint8_t tmp = (dat >> j) & msk;
216 if (reserved_block_code && (tmp == reserved_block_code)) {
217 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
218 (loff_t)(offs + act) <<
219 this->bbt_erase_shift);
220 bbt_mark_entry(this, offs + act,
222 mtd->ecc_stats.bbtblocks++;
226 * Leave it for now, if it's matured we can
227 * move this message to pr_debug.
229 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
230 (loff_t)(offs + act) <<
231 this->bbt_erase_shift);
232 /* Factory marked bad or worn out? */
234 bbt_mark_entry(this, offs + act,
235 BBT_BLOCK_FACTORY_BAD);
237 bbt_mark_entry(this, offs + act,
239 mtd->ecc_stats.badblocks++;
249 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
250 * @this: NAND chip object
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 nand_chip *this, uint8_t *buf,
260 struct nand_bbt_descr *td, int chip)
262 struct mtd_info *mtd = nand_to_mtd(this);
263 u64 targetsize = nanddev_target_size(&this->base);
266 if (td->options & NAND_BBT_PERCHIP) {
268 for (i = 0; i < nanddev_ntargets(&this->base); i++) {
269 if (chip == -1 || chip == i)
270 res = read_bbt(this, buf, td->pages[i],
271 targetsize >> this->bbt_erase_shift,
275 offs += targetsize >> this->bbt_erase_shift;
278 res = read_bbt(this, buf, td->pages[0],
279 mtd->size >> this->bbt_erase_shift, td, 0);
286 /* BBT marker is in the first page, no OOB */
287 static int scan_read_data(struct nand_chip *this, uint8_t *buf, loff_t offs,
288 struct nand_bbt_descr *td)
290 struct mtd_info *mtd = nand_to_mtd(this);
295 if (td->options & NAND_BBT_VERSION)
298 return mtd_read(mtd, offs, len, &retlen, buf);
302 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
303 * @this: NAND chip object
304 * @buf: temporary buffer
305 * @offs: offset at which to scan
306 * @len: length of data region to read
308 * Scan read data from data+OOB. May traverse multiple pages, interleaving
309 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
310 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
312 static int scan_read_oob(struct nand_chip *this, uint8_t *buf, loff_t offs,
315 struct mtd_info *mtd = nand_to_mtd(this);
316 struct mtd_oob_ops ops;
319 ops.mode = MTD_OPS_PLACE_OOB;
321 ops.ooblen = mtd->oobsize;
325 ops.len = min(len, (size_t)mtd->writesize);
326 ops.oobbuf = buf + ops.len;
328 res = mtd_read_oob(mtd, offs, &ops);
330 if (!mtd_is_bitflip_or_eccerr(res))
332 else if (mtd_is_eccerr(res) || !ret)
336 buf += mtd->oobsize + mtd->writesize;
337 len -= mtd->writesize;
338 offs += mtd->writesize;
343 static int scan_read(struct nand_chip *this, uint8_t *buf, loff_t offs,
344 size_t len, struct nand_bbt_descr *td)
346 if (td->options & NAND_BBT_NO_OOB)
347 return scan_read_data(this, buf, offs, td);
349 return scan_read_oob(this, buf, offs, len);
352 /* Scan write data with oob to flash */
353 static int scan_write_bbt(struct nand_chip *this, loff_t offs, size_t len,
354 uint8_t *buf, uint8_t *oob)
356 struct mtd_info *mtd = nand_to_mtd(this);
357 struct mtd_oob_ops ops;
359 ops.mode = MTD_OPS_PLACE_OOB;
361 ops.ooblen = mtd->oobsize;
366 return mtd_write_oob(mtd, offs, &ops);
369 static u32 bbt_get_ver_offs(struct nand_chip *this, struct nand_bbt_descr *td)
371 struct mtd_info *mtd = nand_to_mtd(this);
372 u32 ver_offs = td->veroffs;
374 if (!(td->options & NAND_BBT_NO_OOB))
375 ver_offs += mtd->writesize;
380 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
381 * @this: NAND chip object
382 * @buf: temporary buffer
383 * @td: descriptor for the bad block table
384 * @md: descriptor for the bad block table mirror
386 * Read the bad block table(s) for all chips starting at a given page. We
387 * assume that the bbt bits are in consecutive order.
389 static void read_abs_bbts(struct nand_chip *this, uint8_t *buf,
390 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
392 struct mtd_info *mtd = nand_to_mtd(this);
394 /* Read the primary version, if available */
395 if (td->options & NAND_BBT_VERSION) {
396 scan_read(this, buf, (loff_t)td->pages[0] << this->page_shift,
398 td->version[0] = buf[bbt_get_ver_offs(this, td)];
399 pr_info("Bad block table at page %d, version 0x%02X\n",
400 td->pages[0], td->version[0]);
403 /* Read the mirror version, if available */
404 if (md && (md->options & NAND_BBT_VERSION)) {
405 scan_read(this, buf, (loff_t)md->pages[0] << this->page_shift,
407 md->version[0] = buf[bbt_get_ver_offs(this, md)];
408 pr_info("Bad block table at page %d, version 0x%02X\n",
409 md->pages[0], md->version[0]);
413 /* Scan a given block partially */
414 static int scan_block_fast(struct nand_chip *this, struct nand_bbt_descr *bd,
415 loff_t offs, uint8_t *buf)
417 struct mtd_info *mtd = nand_to_mtd(this);
419 struct mtd_oob_ops ops;
420 int ret, page_offset;
422 ops.ooblen = mtd->oobsize;
426 ops.mode = MTD_OPS_PLACE_OOB;
428 page_offset = nand_bbm_get_next_page(this, 0);
430 while (page_offset >= 0) {
432 * Read the full oob until read_oob is fixed to handle single
433 * byte reads for 16 bit buswidth.
435 ret = mtd_read_oob(mtd, offs + (page_offset * mtd->writesize),
437 /* Ignore ECC errors when checking for BBM */
438 if (ret && !mtd_is_bitflip_or_eccerr(ret))
441 if (check_short_pattern(buf, bd))
444 page_offset = nand_bbm_get_next_page(this, page_offset + 1);
450 /* Check if a potential BBT block is marked as bad */
451 static int bbt_block_checkbad(struct nand_chip *this, struct nand_bbt_descr *td,
452 loff_t offs, uint8_t *buf)
454 struct nand_bbt_descr *bd = this->badblock_pattern;
457 * No need to check for a bad BBT block if the BBM area overlaps with
458 * the bad block table marker area in OOB since writing a BBM here
459 * invalidates the bad block table marker anyway.
461 if (!(td->options & NAND_BBT_NO_OOB) &&
462 td->offs >= bd->offs && td->offs < bd->offs + bd->len)
466 * There is no point in checking for a bad block marker if writing
467 * such marker is not supported
469 if (this->bbt_options & NAND_BBT_NO_OOB_BBM ||
470 this->options & NAND_NO_BBM_QUIRK)
473 if (scan_block_fast(this, bd, offs, buf) > 0)
480 * create_bbt - [GENERIC] Create a bad block table by scanning the device
481 * @this: NAND chip object
482 * @buf: temporary buffer
483 * @bd: descriptor for the good/bad block search pattern
484 * @chip: create the table for a specific chip, -1 read all chips; applies only
485 * if NAND_BBT_PERCHIP option is set
487 * Create a bad block table by scanning the device for the given good/bad block
490 static int create_bbt(struct nand_chip *this, uint8_t *buf,
491 struct nand_bbt_descr *bd, int chip)
493 u64 targetsize = nanddev_target_size(&this->base);
494 struct mtd_info *mtd = nand_to_mtd(this);
495 int i, numblocks, startblock;
498 pr_info("Scanning device for bad blocks\n");
501 numblocks = mtd->size >> this->bbt_erase_shift;
505 if (chip >= nanddev_ntargets(&this->base)) {
506 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
507 chip + 1, nanddev_ntargets(&this->base));
510 numblocks = targetsize >> this->bbt_erase_shift;
511 startblock = chip * numblocks;
512 numblocks += startblock;
513 from = (loff_t)startblock << this->bbt_erase_shift;
516 for (i = startblock; i < numblocks; i++) {
519 BUG_ON(bd->options & NAND_BBT_NO_OOB);
521 ret = scan_block_fast(this, bd, from, buf);
526 bbt_mark_entry(this, i, BBT_BLOCK_FACTORY_BAD);
527 pr_warn("Bad eraseblock %d at 0x%012llx\n",
528 i, (unsigned long long)from);
529 mtd->ecc_stats.badblocks++;
532 from += (1 << this->bbt_erase_shift);
538 * search_bbt - [GENERIC] scan the device for a specific bad block table
539 * @this: NAND chip object
540 * @buf: temporary buffer
541 * @td: descriptor for the bad block table
543 * Read the bad block table by searching for a given ident pattern. Search is
544 * preformed either from the beginning up or from the end of the device
545 * downwards. The search starts always at the start of a block. If the option
546 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
547 * the bad block information of this chip. This is necessary to provide support
548 * for certain DOC devices.
550 * The bbt ident pattern resides in the oob area of the first page in a block.
552 static int search_bbt(struct nand_chip *this, uint8_t *buf,
553 struct nand_bbt_descr *td)
555 u64 targetsize = nanddev_target_size(&this->base);
556 struct mtd_info *mtd = nand_to_mtd(this);
558 int startblock, block, dir;
559 int scanlen = mtd->writesize + mtd->oobsize;
561 int blocktopage = this->bbt_erase_shift - this->page_shift;
563 /* Search direction top -> down? */
564 if (td->options & NAND_BBT_LASTBLOCK) {
565 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
572 /* Do we have a bbt per chip? */
573 if (td->options & NAND_BBT_PERCHIP) {
574 chips = nanddev_ntargets(&this->base);
575 bbtblocks = targetsize >> this->bbt_erase_shift;
576 startblock &= bbtblocks - 1;
579 bbtblocks = mtd->size >> this->bbt_erase_shift;
582 for (i = 0; i < chips; i++) {
583 /* Reset version information */
586 /* Scan the maximum number of blocks */
587 for (block = 0; block < td->maxblocks; block++) {
589 int actblock = startblock + dir * block;
590 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
592 /* Check if block is marked bad */
593 if (bbt_block_checkbad(this, td, offs, buf))
596 /* Read first page */
597 scan_read(this, buf, offs, mtd->writesize, td);
598 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
599 td->pages[i] = actblock << blocktopage;
600 if (td->options & NAND_BBT_VERSION) {
601 offs = bbt_get_ver_offs(this, td);
602 td->version[i] = buf[offs];
607 startblock += targetsize >> this->bbt_erase_shift;
609 /* Check, if we found a bbt for each requested chip */
610 for (i = 0; i < chips; i++) {
611 if (td->pages[i] == -1)
612 pr_warn("Bad block table not found for chip %d\n", i);
614 pr_info("Bad block table found at page %d, version 0x%02X\n",
615 td->pages[i], td->version[i]);
621 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
622 * @this: NAND chip object
623 * @buf: temporary buffer
624 * @td: descriptor for the bad block table
625 * @md: descriptor for the bad block table mirror
627 * Search and read the bad block table(s).
629 static void search_read_bbts(struct nand_chip *this, uint8_t *buf,
630 struct nand_bbt_descr *td,
631 struct nand_bbt_descr *md)
633 /* Search the primary table */
634 search_bbt(this, buf, td);
636 /* Search the mirror table */
638 search_bbt(this, buf, md);
642 * get_bbt_block - Get the first valid eraseblock suitable to store a BBT
643 * @this: the NAND device
644 * @td: the BBT description
645 * @md: the mirror BBT descriptor
646 * @chip: the CHIP selector
648 * This functions returns a positive block number pointing a valid eraseblock
649 * suitable to store a BBT (i.e. in the range reserved for BBT), or -ENOSPC if
650 * all blocks are already used of marked bad. If td->pages[chip] was already
651 * pointing to a valid block we re-use it, otherwise we search for the next
654 static int get_bbt_block(struct nand_chip *this, struct nand_bbt_descr *td,
655 struct nand_bbt_descr *md, int chip)
657 u64 targetsize = nanddev_target_size(&this->base);
658 int startblock, dir, page, numblocks, i;
661 * There was already a version of the table, reuse the page. This
662 * applies for absolute placement too, as we have the page number in
665 if (td->pages[chip] != -1)
666 return td->pages[chip] >>
667 (this->bbt_erase_shift - this->page_shift);
669 numblocks = (int)(targetsize >> this->bbt_erase_shift);
670 if (!(td->options & NAND_BBT_PERCHIP))
671 numblocks *= nanddev_ntargets(&this->base);
674 * Automatic placement of the bad block table. Search direction
677 if (td->options & NAND_BBT_LASTBLOCK) {
678 startblock = numblocks * (chip + 1) - 1;
681 startblock = chip * numblocks;
685 for (i = 0; i < td->maxblocks; i++) {
686 int block = startblock + dir * i;
688 /* Check, if the block is bad */
689 switch (bbt_get_entry(this, block)) {
691 case BBT_BLOCK_FACTORY_BAD:
695 page = block << (this->bbt_erase_shift - this->page_shift);
697 /* Check, if the block is used by the mirror table */
698 if (!md || md->pages[chip] != page)
706 * mark_bbt_block_bad - Mark one of the block reserved for BBT bad
707 * @this: the NAND device
708 * @td: the BBT description
709 * @chip: the CHIP selector
710 * @block: the BBT block to mark
712 * Blocks reserved for BBT can become bad. This functions is an helper to mark
713 * such blocks as bad. It takes care of updating the in-memory BBT, marking the
714 * block as bad using a bad block marker and invalidating the associated
717 static void mark_bbt_block_bad(struct nand_chip *this,
718 struct nand_bbt_descr *td,
724 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
726 to = (loff_t)block << this->bbt_erase_shift;
727 res = nand_markbad_bbm(this, to);
729 pr_warn("nand_bbt: error %d while marking block %d bad\n",
732 td->pages[chip] = -1;
736 * write_bbt - [GENERIC] (Re)write the bad block table
737 * @this: NAND chip object
738 * @buf: temporary buffer
739 * @td: descriptor for the bad block table
740 * @md: descriptor for the bad block table mirror
741 * @chipsel: selector for a specific chip, -1 for all
743 * (Re)write the bad block table.
745 static int write_bbt(struct nand_chip *this, uint8_t *buf,
746 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
749 u64 targetsize = nanddev_target_size(&this->base);
750 struct mtd_info *mtd = nand_to_mtd(this);
751 struct erase_info einfo;
752 int i, res, chip = 0;
753 int bits, page, offs, numblocks, sft, sftmsk;
754 int nrchips, pageoffs, ooboffs;
756 uint8_t rcode = td->reserved_block_code;
757 size_t retlen, len = 0;
759 struct mtd_oob_ops ops;
761 ops.ooblen = mtd->oobsize;
764 ops.mode = MTD_OPS_PLACE_OOB;
768 /* Write bad block table per chip rather than per device? */
769 if (td->options & NAND_BBT_PERCHIP) {
770 numblocks = (int)(targetsize >> this->bbt_erase_shift);
771 /* Full device write or specific chip? */
773 nrchips = nanddev_ntargets(&this->base);
775 nrchips = chipsel + 1;
779 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
783 /* Loop through the chips */
784 while (chip < nrchips) {
787 block = get_bbt_block(this, td, md, chip);
789 pr_err("No space left to write bad block table\n");
795 * get_bbt_block() returns a block number, shift the value to
798 page = block << (this->bbt_erase_shift - this->page_shift);
800 /* Set up shift count and masks for the flash table */
801 bits = td->options & NAND_BBT_NRBITS_MSK;
804 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
807 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
810 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
813 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
816 default: return -EINVAL;
819 to = ((loff_t)page) << this->page_shift;
821 /* Must we save the block contents? */
822 if (td->options & NAND_BBT_SAVECONTENT) {
823 /* Make it block aligned */
824 to &= ~(((loff_t)1 << this->bbt_erase_shift) - 1);
825 len = 1 << this->bbt_erase_shift;
826 res = mtd_read(mtd, to, len, &retlen, buf);
829 pr_info("nand_bbt: error reading block for writing the bad block table\n");
832 pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
835 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
836 ops.oobbuf = &buf[len];
837 res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
838 if (res < 0 || ops.oobretlen != ops.ooblen)
841 /* Calc the byte offset in the buffer */
842 pageoffs = page - (int)(to >> this->page_shift);
843 offs = pageoffs << this->page_shift;
844 /* Preset the bbt area with 0xff */
845 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
846 ooboffs = len + (pageoffs * mtd->oobsize);
848 } else if (td->options & NAND_BBT_NO_OOB) {
851 /* The version byte */
852 if (td->options & NAND_BBT_VERSION)
855 len = (size_t)(numblocks >> sft);
857 /* Make it page aligned! */
858 len = ALIGN(len, mtd->writesize);
859 /* Preset the buffer with 0xff */
860 memset(buf, 0xff, len);
861 /* Pattern is located at the begin of first page */
862 memcpy(buf, td->pattern, td->len);
865 len = (size_t)(numblocks >> sft);
866 /* Make it page aligned! */
867 len = ALIGN(len, mtd->writesize);
868 /* Preset the buffer with 0xff */
869 memset(buf, 0xff, len +
870 (len >> this->page_shift)* mtd->oobsize);
873 /* Pattern is located in oob area of first page */
874 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
877 if (td->options & NAND_BBT_VERSION)
878 buf[ooboffs + td->veroffs] = td->version[chip];
880 /* Walk through the memory table */
881 for (i = 0; i < numblocks; i++) {
883 int sftcnt = (i << (3 - sft)) & sftmsk;
884 dat = bbt_get_entry(this, chip * numblocks + i);
885 /* Do not store the reserved bbt blocks! */
886 buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
889 memset(&einfo, 0, sizeof(einfo));
891 einfo.len = 1 << this->bbt_erase_shift;
892 res = nand_erase_nand(this, &einfo, 1);
894 pr_warn("nand_bbt: error while erasing BBT block %d\n",
896 mark_bbt_block_bad(this, td, chip, block);
900 res = scan_write_bbt(this, to, len, buf,
901 td->options & NAND_BBT_NO_OOB ?
904 pr_warn("nand_bbt: error while writing BBT block %d\n",
906 mark_bbt_block_bad(this, td, chip, block);
910 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
911 (unsigned long long)to, td->version[chip]);
913 /* Mark it as used */
914 td->pages[chip++] = page;
919 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
924 * nand_memory_bbt - [GENERIC] create a memory based bad block table
925 * @this: NAND chip object
926 * @bd: descriptor for the good/bad block search pattern
928 * The function creates a memory based bbt by scanning the device for
929 * manufacturer / software marked good / bad blocks.
931 static inline int nand_memory_bbt(struct nand_chip *this,
932 struct nand_bbt_descr *bd)
934 u8 *pagebuf = nand_get_data_buf(this);
936 return create_bbt(this, pagebuf, bd, -1);
940 * check_create - [GENERIC] create and write bbt(s) if necessary
941 * @this: the NAND device
942 * @buf: temporary buffer
943 * @bd: descriptor for the good/bad block search pattern
945 * The function checks the results of the previous call to read_bbt and creates
946 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
947 * for the chip/device. Update is necessary if one of the tables is missing or
948 * the version nr. of one table is less than the other.
950 static int check_create(struct nand_chip *this, uint8_t *buf,
951 struct nand_bbt_descr *bd)
953 int i, chips, writeops, create, chipsel, res, res2;
954 struct nand_bbt_descr *td = this->bbt_td;
955 struct nand_bbt_descr *md = this->bbt_md;
956 struct nand_bbt_descr *rd, *rd2;
958 /* Do we have a bbt per chip? */
959 if (td->options & NAND_BBT_PERCHIP)
960 chips = nanddev_ntargets(&this->base);
964 for (i = 0; i < chips; i++) {
970 /* Per chip or per device? */
971 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
972 /* Mirrored table available? */
974 if (td->pages[i] == -1 && md->pages[i] == -1) {
977 } else if (td->pages[i] == -1) {
980 } else if (md->pages[i] == -1) {
983 } else if (td->version[i] == md->version[i]) {
985 if (!(td->options & NAND_BBT_VERSION))
987 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
995 if (td->pages[i] == -1) {
1004 /* Create the bad block table by scanning the device? */
1005 if (!(td->options & NAND_BBT_CREATE))
1008 /* Create the table in memory by scanning the chip(s) */
1009 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
1010 create_bbt(this, buf, bd, chipsel);
1017 /* Read back first? */
1019 res = read_abs_bbt(this, buf, rd, chipsel);
1020 if (mtd_is_eccerr(res)) {
1021 /* Mark table as invalid */
1028 /* If they weren't versioned, read both */
1030 res2 = read_abs_bbt(this, buf, rd2, chipsel);
1031 if (mtd_is_eccerr(res2)) {
1032 /* Mark table as invalid */
1034 rd2->version[i] = 0;
1040 /* Scrub the flash table(s)? */
1041 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
1044 /* Update version numbers before writing */
1046 td->version[i] = max(td->version[i], md->version[i]);
1047 md->version[i] = td->version[i];
1050 /* Write the bad block table to the device? */
1051 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1052 res = write_bbt(this, buf, td, md, chipsel);
1057 /* Write the mirror bad block table to the device? */
1058 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1059 res = write_bbt(this, buf, md, td, chipsel);
1068 * nand_update_bbt - update bad block table(s)
1069 * @this: the NAND device
1070 * @offs: the offset of the newly marked block
1072 * The function updates the bad block table(s).
1074 static int nand_update_bbt(struct nand_chip *this, loff_t offs)
1076 struct mtd_info *mtd = nand_to_mtd(this);
1080 struct nand_bbt_descr *td = this->bbt_td;
1081 struct nand_bbt_descr *md = this->bbt_md;
1083 if (!this->bbt || !td)
1086 /* Allocate a temporary buffer for one eraseblock incl. oob */
1087 len = (1 << this->bbt_erase_shift);
1088 len += (len >> this->page_shift) * mtd->oobsize;
1089 buf = kmalloc(len, GFP_KERNEL);
1093 /* Do we have a bbt per chip? */
1094 if (td->options & NAND_BBT_PERCHIP) {
1095 chip = (int)(offs >> this->chip_shift);
1102 td->version[chip]++;
1104 md->version[chip]++;
1106 /* Write the bad block table to the device? */
1107 if (td->options & NAND_BBT_WRITE) {
1108 res = write_bbt(this, buf, td, md, chipsel);
1112 /* Write the mirror bad block table to the device? */
1113 if (md && (md->options & NAND_BBT_WRITE)) {
1114 res = write_bbt(this, buf, md, td, chipsel);
1123 * mark_bbt_region - [GENERIC] mark the bad block table regions
1124 * @this: the NAND device
1125 * @td: bad block table descriptor
1127 * The bad block table regions are marked as "bad" to prevent accidental
1128 * erasures / writes. The regions are identified by the mark 0x02.
1130 static void mark_bbt_region(struct nand_chip *this, struct nand_bbt_descr *td)
1132 u64 targetsize = nanddev_target_size(&this->base);
1133 struct mtd_info *mtd = nand_to_mtd(this);
1134 int i, j, chips, block, nrblocks, update;
1137 /* Do we have a bbt per chip? */
1138 if (td->options & NAND_BBT_PERCHIP) {
1139 chips = nanddev_ntargets(&this->base);
1140 nrblocks = (int)(targetsize >> this->bbt_erase_shift);
1143 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1146 for (i = 0; i < chips; i++) {
1147 if ((td->options & NAND_BBT_ABSPAGE) ||
1148 !(td->options & NAND_BBT_WRITE)) {
1149 if (td->pages[i] == -1)
1151 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1152 oldval = bbt_get_entry(this, block);
1153 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1154 if ((oldval != BBT_BLOCK_RESERVED) &&
1155 td->reserved_block_code)
1156 nand_update_bbt(this, (loff_t)block <<
1157 this->bbt_erase_shift);
1161 if (td->options & NAND_BBT_LASTBLOCK)
1162 block = ((i + 1) * nrblocks) - td->maxblocks;
1164 block = i * nrblocks;
1165 for (j = 0; j < td->maxblocks; j++) {
1166 oldval = bbt_get_entry(this, block);
1167 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1168 if (oldval != BBT_BLOCK_RESERVED)
1173 * If we want reserved blocks to be recorded to flash, and some
1174 * new ones have been marked, then we need to update the stored
1175 * bbts. This should only happen once.
1177 if (update && td->reserved_block_code)
1178 nand_update_bbt(this, (loff_t)(block - 1) <<
1179 this->bbt_erase_shift);
1184 * verify_bbt_descr - verify the bad block description
1185 * @this: the NAND device
1186 * @bd: the table to verify
1188 * This functions performs a few sanity checks on the bad block description
1191 static void verify_bbt_descr(struct nand_chip *this, struct nand_bbt_descr *bd)
1193 u64 targetsize = nanddev_target_size(&this->base);
1194 struct mtd_info *mtd = nand_to_mtd(this);
1202 pattern_len = bd->len;
1203 bits = bd->options & NAND_BBT_NRBITS_MSK;
1205 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1206 !(this->bbt_options & NAND_BBT_USE_FLASH));
1209 if (bd->options & NAND_BBT_VERSION)
1212 if (bd->options & NAND_BBT_NO_OOB) {
1213 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1214 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1216 if (bd->options & NAND_BBT_VERSION)
1217 BUG_ON(bd->veroffs != bd->len);
1218 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1221 if (bd->options & NAND_BBT_PERCHIP)
1222 table_size = targetsize >> this->bbt_erase_shift;
1224 table_size = mtd->size >> this->bbt_erase_shift;
1227 if (bd->options & NAND_BBT_NO_OOB)
1228 table_size += pattern_len;
1229 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1233 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1234 * @this: the NAND device
1235 * @bd: descriptor for the good/bad block search pattern
1237 * The function checks, if a bad block table(s) is/are already available. If
1238 * not it scans the device for manufacturer marked good / bad blocks and writes
1239 * the bad block table(s) to the selected place.
1241 * The bad block table memory is allocated here. It must be freed by calling
1242 * the nand_free_bbt function.
1244 static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
1246 struct mtd_info *mtd = nand_to_mtd(this);
1249 struct nand_bbt_descr *td = this->bbt_td;
1250 struct nand_bbt_descr *md = this->bbt_md;
1252 len = (mtd->size >> (this->bbt_erase_shift + 2)) ? : 1;
1254 * Allocate memory (2bit per block) and clear the memory bad block
1257 this->bbt = kzalloc(len, GFP_KERNEL);
1262 * If no primary table descriptor is given, scan the device to build a
1263 * memory based bad block table.
1266 if ((res = nand_memory_bbt(this, bd))) {
1267 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1272 verify_bbt_descr(this, td);
1273 verify_bbt_descr(this, md);
1275 /* Allocate a temporary buffer for one eraseblock incl. oob */
1276 len = (1 << this->bbt_erase_shift);
1277 len += (len >> this->page_shift) * mtd->oobsize;
1284 /* Is the bbt at a given page? */
1285 if (td->options & NAND_BBT_ABSPAGE) {
1286 read_abs_bbts(this, buf, td, md);
1288 /* Search the bad block table using a pattern in oob */
1289 search_read_bbts(this, buf, td, md);
1292 res = check_create(this, buf, bd);
1296 /* Prevent the bbt regions from erasing / writing */
1297 mark_bbt_region(this, td);
1299 mark_bbt_region(this, md);
1313 * Define some generic bad / good block scan pattern which are used
1314 * while scanning a device for factory marked good / bad blocks.
1316 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1318 /* Generic flash bbt descriptors */
1319 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1320 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1322 static struct nand_bbt_descr bbt_main_descr = {
1323 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1324 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1328 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1329 .pattern = bbt_pattern
1332 static struct nand_bbt_descr bbt_mirror_descr = {
1333 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1334 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1338 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1339 .pattern = mirror_pattern
1342 static struct nand_bbt_descr bbt_main_no_oob_descr = {
1343 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1344 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1348 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1349 .pattern = bbt_pattern
1352 static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1353 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1354 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1358 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1359 .pattern = mirror_pattern
1362 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1364 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1365 * @this: NAND chip to create descriptor for
1367 * This function allocates and initializes a nand_bbt_descr for BBM detection
1368 * based on the properties of @this. The new descriptor is stored in
1369 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1370 * passed to this function.
1372 static int nand_create_badblock_pattern(struct nand_chip *this)
1374 struct nand_bbt_descr *bd;
1375 if (this->badblock_pattern) {
1376 pr_warn("Bad block pattern already allocated; not replacing\n");
1379 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1382 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1383 bd->offs = this->badblockpos;
1384 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1385 bd->pattern = scan_ff_pattern;
1386 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1387 this->badblock_pattern = bd;
1392 * nand_create_bbt - [NAND Interface] Select a default bad block table for the device
1393 * @this: NAND chip object
1395 * This function selects the default bad block table support for the device and
1396 * calls the nand_scan_bbt function.
1398 int nand_create_bbt(struct nand_chip *this)
1402 /* Is a flash based bad block table requested? */
1403 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1404 /* Use the default pattern descriptors */
1405 if (!this->bbt_td) {
1406 if (this->bbt_options & NAND_BBT_NO_OOB) {
1407 this->bbt_td = &bbt_main_no_oob_descr;
1408 this->bbt_md = &bbt_mirror_no_oob_descr;
1410 this->bbt_td = &bbt_main_descr;
1411 this->bbt_md = &bbt_mirror_descr;
1415 this->bbt_td = NULL;
1416 this->bbt_md = NULL;
1419 if (!this->badblock_pattern) {
1420 ret = nand_create_badblock_pattern(this);
1425 return nand_scan_bbt(this, this->badblock_pattern);
1427 EXPORT_SYMBOL(nand_create_bbt);
1430 * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
1431 * @this: NAND chip object
1432 * @offs: offset in the device
1434 int nand_isreserved_bbt(struct nand_chip *this, loff_t offs)
1438 block = (int)(offs >> this->bbt_erase_shift);
1439 return bbt_get_entry(this, block) == BBT_BLOCK_RESERVED;
1443 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1444 * @this: NAND chip object
1445 * @offs: offset in the device
1446 * @allowbbt: allow access to bad block table region
1448 int nand_isbad_bbt(struct nand_chip *this, loff_t offs, int allowbbt)
1452 block = (int)(offs >> this->bbt_erase_shift);
1453 res = bbt_get_entry(this, block);
1455 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1456 (unsigned int)offs, block, res);
1458 if (mtd_check_expert_analysis_mode())
1462 case BBT_BLOCK_GOOD:
1464 case BBT_BLOCK_WORN:
1466 case BBT_BLOCK_RESERVED:
1467 return allowbbt ? 0 : 1;
1473 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1474 * @this: NAND chip object
1475 * @offs: offset of the bad block
1477 int nand_markbad_bbt(struct nand_chip *this, loff_t offs)
1481 block = (int)(offs >> this->bbt_erase_shift);
1483 /* Mark bad block in memory */
1484 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
1486 /* Update flash-based bad block table */
1487 if (this->bbt_options & NAND_BBT_USE_FLASH)
1488 ret = nand_update_bbt(this, offs);