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 * $Id: nand_bbt.c,v 1.36 2005/11/07 11:14:30 gleixner Exp $
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
17 * When nand_scan_bbt is called, then it tries to find the bad block table
18 * depending on the options in the bbt descriptor(s). If a bbt is found
19 * then the contents are read and the memory based bbt is created. If a
20 * mirrored bbt is selected then the mirror is searched too and the
21 * versions are compared. If the mirror has a greater version number
22 * than the mirror bbt is used to build the memory based bbt.
23 * If the tables are not versioned, then we "or" the bad block information.
24 * If one of the bbt's is out of date or does not exist it is (re)created.
25 * If no bbt exists at all then the device is scanned for factory marked
26 * good / bad blocks and the bad block tables are created.
28 * For manufacturer created bbts like the one found on M-SYS DOC devices
29 * the bbt is searched and read but never created
31 * The autogenerated bad block table is located in the last good blocks
32 * of the device. The table is mirrored, so it can be updated eventually.
33 * The table is marked in the oob area with an ident pattern and a version
34 * number which indicates which of both tables is more up to date.
36 * The table uses 2 bits per block
38 * 00b: block is factory marked bad
39 * 01b, 10b: block is marked bad due to wear
41 * The memory bad block table uses the following scheme:
43 * 01b: block is marked bad due to wear
44 * 10b: block is reserved (to protect the bbt area)
45 * 11b: block is factory marked bad
47 * Multichip devices like DOC store the bad block info per floor.
49 * Following assumptions are made:
50 * - bbts start at a page boundary, if autolocated on a block boundary
51 * - the space necessary for a bbt in FLASH does not exceed a block boundary
57 #if defined(CONFIG_CMD_NAND) && !defined(CFG_NAND_LEGACY)
60 #include <linux/mtd/compat.h>
61 #include <linux/mtd/mtd.h>
62 #include <linux/mtd/nand.h>
64 #include <asm/errno.h>
68 #include <linux/slab.h>
69 #include <linux/types.h>
70 #include <linux/mtd/mtd.h>
71 #include <linux/mtd/nand.h>
72 #include <linux/mtd/nand_ecc.h>
73 #include <linux/mtd/compatmac.h>
74 #include <linux/bitops.h>
75 #include <linux/delay.h>
76 #include <linux/vmalloc.h>
80 * check_pattern - [GENERIC] check if a pattern is in the buffer
81 * @buf: the buffer to search
82 * @len: the length of buffer to search
83 * @paglen: the pagelength
84 * @td: search pattern descriptor
86 * Check for a pattern at the given place. Used to search bad block
87 * tables and good / bad block identifiers.
88 * If the SCAN_EMPTY option is set then check, if all bytes except the
89 * pattern area contain 0xff
92 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
97 end = paglen + td->offs;
98 if (td->options & NAND_BBT_SCANEMPTY) {
99 for (i = 0; i < end; i++) {
106 /* Compare the pattern */
107 for (i = 0; i < td->len; i++) {
108 if (p[i] != td->pattern[i])
112 if (td->options & NAND_BBT_SCANEMPTY) {
115 for (i = end; i < len; i++) {
124 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
125 * @buf: the buffer to search
126 * @td: search pattern descriptor
128 * Check for a pattern at the given place. Used to search bad block
129 * tables and good / bad block identifiers. Same as check_pattern, but
130 * no optional empty check
133 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
138 /* Compare the pattern */
139 for (i = 0; i < td->len; i++) {
140 if (p[td->offs + i] != td->pattern[i])
147 * read_bbt - [GENERIC] Read the bad block table starting from page
148 * @mtd: MTD device structure
149 * @buf: temporary buffer
150 * @page: the starting page
151 * @num: the number of bbt descriptors to read
152 * @bits: number of bits per block
153 * @offs: offset in the memory table
154 * @reserved_block_code: Pattern to identify reserved blocks
156 * Read the bad block table starting from page.
159 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
160 int bits, int offs, int reserved_block_code)
162 int res, i, j, act = 0;
163 struct nand_chip *this = mtd->priv;
164 size_t retlen, len, totlen;
166 uint8_t msk = (uint8_t) ((1 << bits) - 1);
168 totlen = (num * bits) >> 3;
169 from = ((loff_t) page) << this->page_shift;
172 len = min(totlen, (size_t) (1 << this->bbt_erase_shift));
173 res = mtd->read(mtd, from, len, &retlen, buf);
176 printk(KERN_INFO "nand_bbt: Error reading bad block table\n");
179 printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
183 for (i = 0; i < len; i++) {
184 uint8_t dat = buf[i];
185 for (j = 0; j < 8; j += bits, act += 2) {
186 uint8_t tmp = (dat >> j) & msk;
189 if (reserved_block_code && (tmp == reserved_block_code)) {
190 printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%08x\n",
191 ((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
192 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
193 mtd->ecc_stats.bbtblocks++;
196 /* Leave it for now, if its matured we can move this
197 * message to MTD_DEBUG_LEVEL0 */
198 printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%08x\n",
199 ((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
200 /* Factory marked bad or worn out ? */
202 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
204 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
205 mtd->ecc_stats.badblocks++;
215 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
216 * @mtd: MTD device structure
217 * @buf: temporary buffer
218 * @td: descriptor for the bad block table
219 * @chip: read the table for a specific chip, -1 read all chips.
220 * Applies only if NAND_BBT_PERCHIP option is set
222 * Read the bad block table for all chips starting at a given page
223 * We assume that the bbt bits are in consecutive order.
225 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
227 struct nand_chip *this = mtd->priv;
231 bits = td->options & NAND_BBT_NRBITS_MSK;
232 if (td->options & NAND_BBT_PERCHIP) {
234 for (i = 0; i < this->numchips; i++) {
235 if (chip == -1 || chip == i)
236 res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
239 offs += this->chipsize >> (this->bbt_erase_shift + 2);
242 res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
250 * Scan read raw data from flash
252 static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
255 struct mtd_oob_ops ops;
257 ops.mode = MTD_OOB_RAW;
259 ops.ooblen = mtd->oobsize;
264 return mtd->read_oob(mtd, offs, &ops);
268 * Scan write data with oob to flash
270 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
271 uint8_t *buf, uint8_t *oob)
273 struct mtd_oob_ops ops;
275 ops.mode = MTD_OOB_PLACE;
277 ops.ooblen = mtd->oobsize;
282 return mtd->write_oob(mtd, offs, &ops);
286 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
287 * @mtd: MTD device structure
288 * @buf: temporary buffer
289 * @td: descriptor for the bad block table
290 * @md: descriptor for the bad block table mirror
292 * Read the bad block table(s) for all chips starting at a given page
293 * We assume that the bbt bits are in consecutive order.
296 static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
297 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
299 struct nand_chip *this = mtd->priv;
301 /* Read the primary version, if available */
302 if (td->options & NAND_BBT_VERSION) {
303 scan_read_raw(mtd, buf, td->pages[0] << this->page_shift,
305 td->version[0] = buf[mtd->writesize + td->veroffs];
306 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
307 td->pages[0], td->version[0]);
310 /* Read the mirror version, if available */
311 if (md && (md->options & NAND_BBT_VERSION)) {
312 scan_read_raw(mtd, buf, md->pages[0] << this->page_shift,
314 md->version[0] = buf[mtd->writesize + md->veroffs];
315 printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n",
316 md->pages[0], md->version[0]);
322 * Scan a given block full
324 static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd,
325 loff_t offs, uint8_t *buf, size_t readlen,
326 int scanlen, int len)
330 ret = scan_read_raw(mtd, buf, offs, readlen);
334 for (j = 0; j < len; j++, buf += scanlen) {
335 if (check_pattern(buf, scanlen, mtd->writesize, bd))
342 * Scan a given block partially
344 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
345 loff_t offs, uint8_t *buf, int len)
347 struct mtd_oob_ops ops;
350 ops.ooblen = mtd->oobsize;
354 ops.mode = MTD_OOB_PLACE;
356 for (j = 0; j < len; j++) {
358 * Read the full oob until read_oob is fixed to
359 * handle single byte reads for 16 bit
362 ret = mtd->read_oob(mtd, offs, &ops);
366 if (check_short_pattern(buf, bd))
369 offs += mtd->writesize;
375 * create_bbt - [GENERIC] Create a bad block table by scanning the device
376 * @mtd: MTD device structure
377 * @buf: temporary buffer
378 * @bd: descriptor for the good/bad block search pattern
379 * @chip: create the table for a specific chip, -1 read all chips.
380 * Applies only if NAND_BBT_PERCHIP option is set
382 * Create a bad block table by scanning the device
383 * for the given good/bad block identify pattern
385 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
386 struct nand_bbt_descr *bd, int chip)
388 struct nand_chip *this = mtd->priv;
389 int i, numblocks, len, scanlen;
394 MTDDEBUG (MTD_DEBUG_LEVEL0, "Scanning device for bad blocks\n");
396 if (bd->options & NAND_BBT_SCANALLPAGES)
397 len = 1 << (this->bbt_erase_shift - this->page_shift);
399 if (bd->options & NAND_BBT_SCAN2NDPAGE)
405 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
406 /* We need only read few bytes from the OOB area */
410 /* Full page content should be read */
411 scanlen = mtd->writesize + mtd->oobsize;
412 readlen = len * mtd->writesize;
416 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
417 * below as it makes shifting and masking less painful */
418 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
422 if (chip >= this->numchips) {
423 printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
424 chip + 1, this->numchips);
427 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
428 startblock = chip * numblocks;
429 numblocks += startblock;
430 from = startblock << (this->bbt_erase_shift - 1);
433 for (i = startblock; i < numblocks;) {
436 if (bd->options & NAND_BBT_SCANALLPAGES)
437 ret = scan_block_full(mtd, bd, from, buf, readlen,
440 ret = scan_block_fast(mtd, bd, from, buf, len);
446 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
447 MTDDEBUG (MTD_DEBUG_LEVEL0,
448 "Bad eraseblock %d at 0x%08x\n",
449 i >> 1, (unsigned int)from);
450 mtd->ecc_stats.badblocks++;
454 from += (1 << this->bbt_erase_shift);
460 * search_bbt - [GENERIC] scan the device for a specific bad block table
461 * @mtd: MTD device structure
462 * @buf: temporary buffer
463 * @td: descriptor for the bad block table
465 * Read the bad block table by searching for a given ident pattern.
466 * Search is preformed either from the beginning up or from the end of
467 * the device downwards. The search starts always at the start of a
469 * If the option NAND_BBT_PERCHIP is given, each chip is searched
470 * for a bbt, which contains the bad block information of this chip.
471 * This is necessary to provide support for certain DOC devices.
473 * The bbt ident pattern resides in the oob area of the first page
476 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
478 struct nand_chip *this = mtd->priv;
480 int bits, startblock, block, dir;
481 int scanlen = mtd->writesize + mtd->oobsize;
483 int blocktopage = this->bbt_erase_shift - this->page_shift;
485 /* Search direction top -> down ? */
486 if (td->options & NAND_BBT_LASTBLOCK) {
487 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
494 /* Do we have a bbt per chip ? */
495 if (td->options & NAND_BBT_PERCHIP) {
496 chips = this->numchips;
497 bbtblocks = this->chipsize >> this->bbt_erase_shift;
498 startblock &= bbtblocks - 1;
501 bbtblocks = mtd->size >> this->bbt_erase_shift;
504 /* Number of bits for each erase block in the bbt */
505 bits = td->options & NAND_BBT_NRBITS_MSK;
507 for (i = 0; i < chips; i++) {
508 /* Reset version information */
511 /* Scan the maximum number of blocks */
512 for (block = 0; block < td->maxblocks; block++) {
514 int actblock = startblock + dir * block;
515 loff_t offs = actblock << this->bbt_erase_shift;
517 /* Read first page */
518 scan_read_raw(mtd, buf, offs, mtd->writesize);
519 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
520 td->pages[i] = actblock << blocktopage;
521 if (td->options & NAND_BBT_VERSION) {
522 td->version[i] = buf[mtd->writesize + td->veroffs];
527 startblock += this->chipsize >> this->bbt_erase_shift;
529 /* Check, if we found a bbt for each requested chip */
530 for (i = 0; i < chips; i++) {
531 if (td->pages[i] == -1)
532 printk(KERN_WARNING "Bad block table not found for chip %d\n", i);
534 printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i],
541 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
542 * @mtd: MTD device structure
543 * @buf: temporary buffer
544 * @td: descriptor for the bad block table
545 * @md: descriptor for the bad block table mirror
547 * Search and read the bad block table(s)
549 static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md)
551 /* Search the primary table */
552 search_bbt(mtd, buf, td);
554 /* Search the mirror table */
556 search_bbt(mtd, buf, md);
558 /* Force result check */
563 * write_bbt - [GENERIC] (Re)write the bad block table
565 * @mtd: MTD device structure
566 * @buf: temporary buffer
567 * @td: descriptor for the bad block table
568 * @md: descriptor for the bad block table mirror
569 * @chipsel: selector for a specific chip, -1 for all
571 * (Re)write the bad block table
574 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
575 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
578 struct nand_chip *this = mtd->priv;
579 struct erase_info einfo;
580 int i, j, res, chip = 0;
581 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
582 int nrchips, bbtoffs, pageoffs, ooboffs;
584 uint8_t rcode = td->reserved_block_code;
585 size_t retlen, len = 0;
587 struct mtd_oob_ops ops;
589 ops.ooblen = mtd->oobsize;
592 ops.mode = MTD_OOB_PLACE;
596 /* Write bad block table per chip rather than per device ? */
597 if (td->options & NAND_BBT_PERCHIP) {
598 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
599 /* Full device write or specific chip ? */
601 nrchips = this->numchips;
603 nrchips = chipsel + 1;
607 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
611 /* Loop through the chips */
612 for (; chip < nrchips; chip++) {
614 /* There was already a version of the table, reuse the page
615 * This applies for absolute placement too, as we have the
616 * page nr. in td->pages.
618 if (td->pages[chip] != -1) {
619 page = td->pages[chip];
623 /* Automatic placement of the bad block table */
624 /* Search direction top -> down ? */
625 if (td->options & NAND_BBT_LASTBLOCK) {
626 startblock = numblocks * (chip + 1) - 1;
629 startblock = chip * numblocks;
633 for (i = 0; i < td->maxblocks; i++) {
634 int block = startblock + dir * i;
635 /* Check, if the block is bad */
636 switch ((this->bbt[block >> 2] >>
637 (2 * (block & 0x03))) & 0x03) {
643 (this->bbt_erase_shift - this->page_shift);
644 /* Check, if the block is used by the mirror table */
645 if (!md || md->pages[chip] != page)
648 printk(KERN_ERR "No space left to write bad block table\n");
652 /* Set up shift count and masks for the flash table */
653 bits = td->options & NAND_BBT_NRBITS_MSK;
656 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
659 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
662 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
665 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
668 default: return -EINVAL;
671 bbtoffs = chip * (numblocks >> 2);
673 to = ((loff_t) page) << this->page_shift;
675 /* Must we save the block contents ? */
676 if (td->options & NAND_BBT_SAVECONTENT) {
677 /* Make it block aligned */
678 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
679 len = 1 << this->bbt_erase_shift;
680 res = mtd->read(mtd, to, len, &retlen, buf);
683 printk(KERN_INFO "nand_bbt: Error "
684 "reading block for writing "
685 "the bad block table\n");
688 printk(KERN_WARNING "nand_bbt: ECC error "
689 "while reading block for writing "
690 "bad block table\n");
693 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
694 ops.oobbuf = &buf[len];
695 res = mtd->read_oob(mtd, to + mtd->writesize, &ops);
696 if (res < 0 || ops.oobretlen != ops.ooblen)
699 /* Calc the byte offset in the buffer */
700 pageoffs = page - (int)(to >> this->page_shift);
701 offs = pageoffs << this->page_shift;
702 /* Preset the bbt area with 0xff */
703 memset(&buf[offs], 0xff, (size_t) (numblocks >> sft));
704 ooboffs = len + (pageoffs * mtd->oobsize);
708 len = (size_t) (numblocks >> sft);
709 /* Make it page aligned ! */
710 len = (len + (mtd->writesize - 1)) &
711 ~(mtd->writesize - 1);
712 /* Preset the buffer with 0xff */
713 memset(buf, 0xff, len +
714 (len >> this->page_shift)* mtd->oobsize);
717 /* Pattern is located in oob area of first page */
718 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
721 if (td->options & NAND_BBT_VERSION)
722 buf[ooboffs + td->veroffs] = td->version[chip];
724 /* walk through the memory table */
725 for (i = 0; i < numblocks;) {
727 dat = this->bbt[bbtoffs + (i >> 2)];
728 for (j = 0; j < 4; j++, i++) {
729 int sftcnt = (i << (3 - sft)) & sftmsk;
730 /* Do not store the reserved bbt blocks ! */
731 buf[offs + (i >> sft)] &=
732 ~(msk[dat & 0x03] << sftcnt);
737 memset(&einfo, 0, sizeof(einfo));
739 einfo.addr = (unsigned long)to;
740 einfo.len = 1 << this->bbt_erase_shift;
741 res = nand_erase_nand(mtd, &einfo, 1);
745 res = scan_write_bbt(mtd, to, len, buf, &buf[len]);
749 printk(KERN_DEBUG "Bad block table written to 0x%08x, version "
750 "0x%02X\n", (unsigned int)to, td->version[chip]);
752 /* Mark it as used */
753 td->pages[chip] = page;
759 "nand_bbt: Error while writing bad block table %d\n", res);
764 * nand_memory_bbt - [GENERIC] create a memory based bad block table
765 * @mtd: MTD device structure
766 * @bd: descriptor for the good/bad block search pattern
768 * The function creates a memory based bbt by scanning the device
769 * for manufacturer / software marked good / bad blocks
771 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
773 struct nand_chip *this = mtd->priv;
775 bd->options &= ~NAND_BBT_SCANEMPTY;
776 return create_bbt(mtd, this->buffers->databuf, bd, -1);
780 * check_create - [GENERIC] create and write bbt(s) if necessary
781 * @mtd: MTD device structure
782 * @buf: temporary buffer
783 * @bd: descriptor for the good/bad block search pattern
785 * The function checks the results of the previous call to read_bbt
786 * and creates / updates the bbt(s) if necessary
787 * Creation is necessary if no bbt was found for the chip/device
788 * Update is necessary if one of the tables is missing or the
789 * version nr. of one table is less than the other
791 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
793 int i, chips, writeops, chipsel, res;
794 struct nand_chip *this = mtd->priv;
795 struct nand_bbt_descr *td = this->bbt_td;
796 struct nand_bbt_descr *md = this->bbt_md;
797 struct nand_bbt_descr *rd, *rd2;
799 /* Do we have a bbt per chip ? */
800 if (td->options & NAND_BBT_PERCHIP)
801 chips = this->numchips;
805 for (i = 0; i < chips; i++) {
809 /* Per chip or per device ? */
810 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
811 /* Mirrored table avilable ? */
813 if (td->pages[i] == -1 && md->pages[i] == -1) {
818 if (td->pages[i] == -1) {
820 td->version[i] = md->version[i];
825 if (md->pages[i] == -1) {
827 md->version[i] = td->version[i];
832 if (td->version[i] == md->version[i]) {
834 if (!(td->options & NAND_BBT_VERSION))
839 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
841 md->version[i] = td->version[i];
845 td->version[i] = md->version[i];
852 if (td->pages[i] == -1) {
860 /* Create the bad block table by scanning the device ? */
861 if (!(td->options & NAND_BBT_CREATE))
864 /* Create the table in memory by scanning the chip(s) */
865 create_bbt(mtd, buf, bd, chipsel);
871 /* read back first ? */
873 read_abs_bbt(mtd, buf, rd, chipsel);
874 /* If they weren't versioned, read both. */
876 read_abs_bbt(mtd, buf, rd2, chipsel);
878 /* Write the bad block table to the device ? */
879 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
880 res = write_bbt(mtd, buf, td, md, chipsel);
885 /* Write the mirror bad block table to the device ? */
886 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
887 res = write_bbt(mtd, buf, md, td, chipsel);
896 * mark_bbt_regions - [GENERIC] mark the bad block table regions
897 * @mtd: MTD device structure
898 * @td: bad block table descriptor
900 * The bad block table regions are marked as "bad" to prevent
901 * accidental erasures / writes. The regions are identified by
904 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
906 struct nand_chip *this = mtd->priv;
907 int i, j, chips, block, nrblocks, update;
908 uint8_t oldval, newval;
910 /* Do we have a bbt per chip ? */
911 if (td->options & NAND_BBT_PERCHIP) {
912 chips = this->numchips;
913 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
916 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
919 for (i = 0; i < chips; i++) {
920 if ((td->options & NAND_BBT_ABSPAGE) ||
921 !(td->options & NAND_BBT_WRITE)) {
922 if (td->pages[i] == -1)
924 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
926 oldval = this->bbt[(block >> 3)];
927 newval = oldval | (0x2 << (block & 0x06));
928 this->bbt[(block >> 3)] = newval;
929 if ((oldval != newval) && td->reserved_block_code)
930 nand_update_bbt(mtd, block << (this->bbt_erase_shift - 1));
934 if (td->options & NAND_BBT_LASTBLOCK)
935 block = ((i + 1) * nrblocks) - td->maxblocks;
937 block = i * nrblocks;
939 for (j = 0; j < td->maxblocks; j++) {
940 oldval = this->bbt[(block >> 3)];
941 newval = oldval | (0x2 << (block & 0x06));
942 this->bbt[(block >> 3)] = newval;
943 if (oldval != newval)
947 /* If we want reserved blocks to be recorded to flash, and some
948 new ones have been marked, then we need to update the stored
949 bbts. This should only happen once. */
950 if (update && td->reserved_block_code)
951 nand_update_bbt(mtd, (block - 2) << (this->bbt_erase_shift - 1));
956 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
957 * @mtd: MTD device structure
958 * @bd: descriptor for the good/bad block search pattern
960 * The function checks, if a bad block table(s) is/are already
961 * available. If not it scans the device for manufacturer
962 * marked good / bad blocks and writes the bad block table(s) to
963 * the selected place.
965 * The bad block table memory is allocated here. It must be freed
966 * by calling the nand_free_bbt function.
969 int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
971 struct nand_chip *this = mtd->priv;
974 struct nand_bbt_descr *td = this->bbt_td;
975 struct nand_bbt_descr *md = this->bbt_md;
977 len = mtd->size >> (this->bbt_erase_shift + 2);
978 /* Allocate memory (2bit per block) and clear the memory bad block table */
979 this->bbt = kzalloc(len, GFP_KERNEL);
981 printk(KERN_ERR "nand_scan_bbt: Out of memory\n");
985 /* If no primary table decriptor is given, scan the device
986 * to build a memory based bad block table
989 if ((res = nand_memory_bbt(mtd, bd))) {
990 printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
997 /* Allocate a temporary buffer for one eraseblock incl. oob */
998 len = (1 << this->bbt_erase_shift);
999 len += (len >> this->page_shift) * mtd->oobsize;
1002 printk(KERN_ERR "nand_bbt: Out of memory\n");
1008 /* Is the bbt at a given page ? */
1009 if (td->options & NAND_BBT_ABSPAGE) {
1010 res = read_abs_bbts(mtd, buf, td, md);
1012 /* Search the bad block table using a pattern in oob */
1013 res = search_read_bbts(mtd, buf, td, md);
1017 res = check_create(mtd, buf, bd);
1019 /* Prevent the bbt regions from erasing / writing */
1020 mark_bbt_region(mtd, td);
1022 mark_bbt_region(mtd, md);
1029 * nand_update_bbt - [NAND Interface] update bad block table(s)
1030 * @mtd: MTD device structure
1031 * @offs: the offset of the newly marked block
1033 * The function updates the bad block table(s)
1035 int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1037 struct nand_chip *this = mtd->priv;
1038 int len, res = 0, writeops = 0;
1041 struct nand_bbt_descr *td = this->bbt_td;
1042 struct nand_bbt_descr *md = this->bbt_md;
1044 if (!this->bbt || !td)
1047 len = mtd->size >> (this->bbt_erase_shift + 2);
1048 /* Allocate a temporary buffer for one eraseblock incl. oob */
1049 len = (1 << this->bbt_erase_shift);
1050 len += (len >> this->page_shift) * mtd->oobsize;
1051 buf = kmalloc(len, GFP_KERNEL);
1053 printk(KERN_ERR "nand_update_bbt: Out of memory\n");
1057 writeops = md != NULL ? 0x03 : 0x01;
1059 /* Do we have a bbt per chip ? */
1060 if (td->options & NAND_BBT_PERCHIP) {
1061 chip = (int)(offs >> this->chip_shift);
1068 td->version[chip]++;
1070 md->version[chip]++;
1072 /* Write the bad block table to the device ? */
1073 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1074 res = write_bbt(mtd, buf, td, md, chipsel);
1078 /* Write the mirror bad block table to the device ? */
1079 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1080 res = write_bbt(mtd, buf, md, td, chipsel);
1088 /* Define some generic bad / good block scan pattern which are used
1089 * while scanning a device for factory marked good / bad blocks. */
1090 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1092 static struct nand_bbt_descr smallpage_memorybased = {
1093 .options = NAND_BBT_SCAN2NDPAGE,
1096 .pattern = scan_ff_pattern
1099 static struct nand_bbt_descr largepage_memorybased = {
1103 .pattern = scan_ff_pattern
1106 static struct nand_bbt_descr smallpage_flashbased = {
1107 .options = NAND_BBT_SCAN2NDPAGE,
1110 .pattern = scan_ff_pattern
1113 static struct nand_bbt_descr largepage_flashbased = {
1114 .options = NAND_BBT_SCAN2NDPAGE,
1117 .pattern = scan_ff_pattern
1120 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1122 static struct nand_bbt_descr agand_flashbased = {
1123 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1126 .pattern = scan_agand_pattern
1129 /* Generic flash bbt decriptors
1131 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1132 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1134 static struct nand_bbt_descr bbt_main_descr = {
1135 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1136 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1141 .pattern = bbt_pattern
1144 static struct nand_bbt_descr bbt_mirror_descr = {
1145 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1146 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1151 .pattern = mirror_pattern
1155 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1156 * @mtd: MTD device structure
1158 * This function selects the default bad block table
1159 * support for the device and calls the nand_scan_bbt function
1162 int nand_default_bbt(struct mtd_info *mtd)
1164 struct nand_chip *this = mtd->priv;
1166 /* Default for AG-AND. We must use a flash based
1167 * bad block table as the devices have factory marked
1168 * _good_ blocks. Erasing those blocks leads to loss
1169 * of the good / bad information, so we _must_ store
1170 * this information in a good / bad table during
1173 if (this->options & NAND_IS_AND) {
1174 /* Use the default pattern descriptors */
1175 if (!this->bbt_td) {
1176 this->bbt_td = &bbt_main_descr;
1177 this->bbt_md = &bbt_mirror_descr;
1179 this->options |= NAND_USE_FLASH_BBT;
1180 return nand_scan_bbt(mtd, &agand_flashbased);
1183 /* Is a flash based bad block table requested ? */
1184 if (this->options & NAND_USE_FLASH_BBT) {
1185 /* Use the default pattern descriptors */
1186 if (!this->bbt_td) {
1187 this->bbt_td = &bbt_main_descr;
1188 this->bbt_md = &bbt_mirror_descr;
1190 if (!this->badblock_pattern) {
1191 this->badblock_pattern = (mtd->writesize > 512) ? &largepage_flashbased : &smallpage_flashbased;
1194 this->bbt_td = NULL;
1195 this->bbt_md = NULL;
1196 if (!this->badblock_pattern) {
1197 this->badblock_pattern = (mtd->writesize > 512) ?
1198 &largepage_memorybased : &smallpage_memorybased;
1201 return nand_scan_bbt(mtd, this->badblock_pattern);
1205 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1206 * @mtd: MTD device structure
1207 * @offs: offset in the device
1208 * @allowbbt: allow access to bad block table region
1211 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1213 struct nand_chip *this = mtd->priv;
1217 /* Get block number * 2 */
1218 block = (int)(offs >> (this->bbt_erase_shift - 1));
1219 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1221 MTDDEBUG (MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1222 "(block %d) 0x%02x\n", (unsigned int)offs, res, block >> 1);
1230 return allowbbt ? 0 : 1;
1235 /* XXX U-BOOT XXX */
1237 EXPORT_SYMBOL(nand_scan_bbt);
1238 EXPORT_SYMBOL(nand_default_bbt);