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 1.33 2005/06/14 15:47:56 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24 * If one of the bbt's is out of date or does not exist it is (re)created.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 neccecary for a bbt in FLASH does not exceed a block boundary
55 #include <linux/slab.h>
56 #include <linux/types.h>
57 #include <linux/mtd/mtd.h>
58 #include <linux/mtd/nand.h>
59 #include <linux/mtd/nand_ecc.h>
60 #include <linux/mtd/compatmac.h>
61 #include <linux/bitops.h>
62 #include <linux/delay.h>
66 * check_pattern - [GENERIC] check if a pattern is in the buffer
67 * @buf: the buffer to search
68 * @len: the length of buffer to search
69 * @paglen: the pagelength
70 * @td: search pattern descriptor
72 * Check for a pattern at the given place. Used to search bad block
73 * tables and good / bad block identifiers.
74 * If the SCAN_EMPTY option is set then check, if all bytes except the
75 * pattern area contain 0xff
78 static int check_pattern (uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
83 end = paglen + td->offs;
84 if (td->options & NAND_BBT_SCANEMPTY) {
85 for (i = 0; i < end; i++) {
92 /* Compare the pattern */
93 for (i = 0; i < td->len; i++) {
94 if (p[i] != td->pattern[i])
98 if (td->options & NAND_BBT_SCANEMPTY) {
101 for (i = end; i < len; i++) {
110 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
111 * @buf: the buffer to search
112 * @len: the length of buffer to search
113 * @paglen: the pagelength
114 * @td: search pattern descriptor
116 * Check for a pattern at the given place. Used to search bad block
117 * tables and good / bad block identifiers. Same as check_pattern, but
118 * no optional empty check and the pattern is expected to start
122 static int check_short_pattern (uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
127 /* Compare the pattern */
128 for (i = 0; i < td->len; i++) {
129 if (p[i] != td->pattern[i])
136 * read_bbt - [GENERIC] Read the bad block table starting from page
137 * @mtd: MTD device structure
138 * @buf: temporary buffer
139 * @page: the starting page
140 * @num: the number of bbt descriptors to read
141 * @bits: number of bits per block
142 * @offs: offset in the memory table
143 * @reserved_block_code: Pattern to identify reserved blocks
145 * Read the bad block table starting from page.
148 static int read_bbt (struct mtd_info *mtd, uint8_t *buf, int page, int num,
149 int bits, int offs, int reserved_block_code)
151 int res, i, j, act = 0;
152 struct nand_chip *this = mtd->priv;
153 size_t retlen, len, totlen;
155 uint8_t msk = (uint8_t) ((1 << bits) - 1);
157 totlen = (num * bits) >> 3;
158 from = ((loff_t)page) << this->page_shift;
161 len = min (totlen, (size_t) (1 << this->bbt_erase_shift));
162 res = mtd->read_ecc (mtd, from, len, &retlen, buf, NULL, this->autooob);
165 printk (KERN_INFO "nand_bbt: Error reading bad block table\n");
168 printk (KERN_WARNING "nand_bbt: ECC error while reading bad block table\n");
172 for (i = 0; i < len; i++) {
173 uint8_t dat = buf[i];
174 for (j = 0; j < 8; j += bits, act += 2) {
175 uint8_t tmp = (dat >> j) & msk;
178 if (reserved_block_code &&
179 (tmp == reserved_block_code)) {
180 printk (KERN_DEBUG "nand_read_bbt: Reserved block at 0x%08x\n",
181 ((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
182 this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06);
185 /* Leave it for now, if its matured we can move this
186 * message to MTD_DEBUG_LEVEL0 */
187 printk (KERN_DEBUG "nand_read_bbt: Bad block at 0x%08x\n",
188 ((offs << 2) + (act >> 1)) << this->bbt_erase_shift);
189 /* Factory marked bad or worn out ? */
191 this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06);
193 this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06);
203 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
204 * @mtd: MTD device structure
205 * @buf: temporary buffer
206 * @td: descriptor for the bad block table
207 * @chip: read the table for a specific chip, -1 read all chips.
208 * Applies only if NAND_BBT_PERCHIP option is set
210 * Read the bad block table for all chips starting at a given page
211 * We assume that the bbt bits are in consecutive order.
213 static int read_abs_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
215 struct nand_chip *this = mtd->priv;
219 bits = td->options & NAND_BBT_NRBITS_MSK;
220 if (td->options & NAND_BBT_PERCHIP) {
222 for (i = 0; i < this->numchips; i++) {
223 if (chip == -1 || chip == i)
224 res = read_bbt (mtd, buf, td->pages[i], this->chipsize >> this->bbt_erase_shift, bits, offs, td->reserved_block_code);
227 offs += this->chipsize >> (this->bbt_erase_shift + 2);
230 res = read_bbt (mtd, buf, td->pages[0], mtd->size >> this->bbt_erase_shift, bits, 0, td->reserved_block_code);
238 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
239 * @mtd: MTD device structure
240 * @buf: temporary buffer
241 * @td: descriptor for the bad block table
242 * @md: descriptor for the bad block table mirror
244 * Read the bad block table(s) for all chips starting at a given page
245 * We assume that the bbt bits are in consecutive order.
248 static int read_abs_bbts (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td,
249 struct nand_bbt_descr *md)
251 struct nand_chip *this = mtd->priv;
253 /* Read the primary version, if available */
254 if (td->options & NAND_BBT_VERSION) {
255 nand_read_raw (mtd, buf, td->pages[0] << this->page_shift, mtd->oobblock, mtd->oobsize);
256 td->version[0] = buf[mtd->oobblock + td->veroffs];
257 printk (KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", td->pages[0], td->version[0]);
260 /* Read the mirror version, if available */
261 if (md && (md->options & NAND_BBT_VERSION)) {
262 nand_read_raw (mtd, buf, md->pages[0] << this->page_shift, mtd->oobblock, mtd->oobsize);
263 md->version[0] = buf[mtd->oobblock + md->veroffs];
264 printk (KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", md->pages[0], md->version[0]);
271 * create_bbt - [GENERIC] Create a bad block table by scanning the device
272 * @mtd: MTD device structure
273 * @buf: temporary buffer
274 * @bd: descriptor for the good/bad block search pattern
275 * @chip: create the table for a specific chip, -1 read all chips.
276 * Applies only if NAND_BBT_PERCHIP option is set
278 * Create a bad block table by scanning the device
279 * for the given good/bad block identify pattern
281 static int create_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd, int chip)
283 struct nand_chip *this = mtd->priv;
284 int i, j, numblocks, len, scanlen;
287 size_t readlen, ooblen;
289 printk (KERN_INFO "Scanning device for bad blocks\n");
291 if (bd->options & NAND_BBT_SCANALLPAGES)
292 len = 1 << (this->bbt_erase_shift - this->page_shift);
294 if (bd->options & NAND_BBT_SCAN2NDPAGE)
300 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
301 /* We need only read few bytes from the OOB area */
302 scanlen = ooblen = 0;
305 /* Full page content should be read */
306 scanlen = mtd->oobblock + mtd->oobsize;
307 readlen = len * mtd->oobblock;
308 ooblen = len * mtd->oobsize;
312 /* Note that numblocks is 2 * (real numblocks) here, see i+=2 below as it
313 * makes shifting and masking less painful */
314 numblocks = mtd->size >> (this->bbt_erase_shift - 1);
318 if (chip >= this->numchips) {
319 printk (KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n",
320 chip + 1, this->numchips);
323 numblocks = this->chipsize >> (this->bbt_erase_shift - 1);
324 startblock = chip * numblocks;
325 numblocks += startblock;
326 from = startblock << (this->bbt_erase_shift - 1);
329 for (i = startblock; i < numblocks;) {
332 if (bd->options & NAND_BBT_SCANEMPTY)
333 if ((ret = nand_read_raw (mtd, buf, from, readlen, ooblen)))
336 for (j = 0; j < len; j++) {
337 if (!(bd->options & NAND_BBT_SCANEMPTY)) {
340 /* No need to read pages fully, just read required OOB bytes */
341 ret = mtd->read_oob(mtd, from + j * mtd->oobblock + bd->offs,
342 readlen, &retlen, &buf[0]);
346 if (check_short_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
347 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
348 printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
349 i >> 1, (unsigned int) from);
353 if (check_pattern (&buf[j * scanlen], scanlen, mtd->oobblock, bd)) {
354 this->bbt[i >> 3] |= 0x03 << (i & 0x6);
355 printk (KERN_WARNING "Bad eraseblock %d at 0x%08x\n",
356 i >> 1, (unsigned int) from);
362 from += (1 << this->bbt_erase_shift);
368 * search_bbt - [GENERIC] scan the device for a specific bad block table
369 * @mtd: MTD device structure
370 * @buf: temporary buffer
371 * @td: descriptor for the bad block table
373 * Read the bad block table by searching for a given ident pattern.
374 * Search is preformed either from the beginning up or from the end of
375 * the device downwards. The search starts always at the start of a
377 * If the option NAND_BBT_PERCHIP is given, each chip is searched
378 * for a bbt, which contains the bad block information of this chip.
379 * This is neccecary to provide support for certain DOC devices.
381 * The bbt ident pattern resides in the oob area of the first page
384 static int search_bbt (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
386 struct nand_chip *this = mtd->priv;
388 int bits, startblock, block, dir;
389 int scanlen = mtd->oobblock + mtd->oobsize;
392 /* Search direction top -> down ? */
393 if (td->options & NAND_BBT_LASTBLOCK) {
394 startblock = (mtd->size >> this->bbt_erase_shift) -1;
401 /* Do we have a bbt per chip ? */
402 if (td->options & NAND_BBT_PERCHIP) {
403 chips = this->numchips;
404 bbtblocks = this->chipsize >> this->bbt_erase_shift;
405 startblock &= bbtblocks - 1;
408 bbtblocks = mtd->size >> this->bbt_erase_shift;
411 /* Number of bits for each erase block in the bbt */
412 bits = td->options & NAND_BBT_NRBITS_MSK;
414 for (i = 0; i < chips; i++) {
415 /* Reset version information */
418 /* Scan the maximum number of blocks */
419 for (block = 0; block < td->maxblocks; block++) {
420 int actblock = startblock + dir * block;
421 /* Read first page */
422 nand_read_raw (mtd, buf, actblock << this->bbt_erase_shift, mtd->oobblock, mtd->oobsize);
423 if (!check_pattern(buf, scanlen, mtd->oobblock, td)) {
424 td->pages[i] = actblock << (this->bbt_erase_shift - this->page_shift);
425 if (td->options & NAND_BBT_VERSION) {
426 td->version[i] = buf[mtd->oobblock + td->veroffs];
431 startblock += this->chipsize >> this->bbt_erase_shift;
433 /* Check, if we found a bbt for each requested chip */
434 for (i = 0; i < chips; i++) {
435 if (td->pages[i] == -1)
436 printk (KERN_WARNING "Bad block table not found for chip %d\n", i);
438 printk (KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i], td->version[i]);
444 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
445 * @mtd: MTD device structure
446 * @buf: temporary buffer
447 * @td: descriptor for the bad block table
448 * @md: descriptor for the bad block table mirror
450 * Search and read the bad block table(s)
452 static int search_read_bbts (struct mtd_info *mtd, uint8_t *buf,
453 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
455 /* Search the primary table */
456 search_bbt (mtd, buf, td);
458 /* Search the mirror table */
460 search_bbt (mtd, buf, md);
462 /* Force result check */
468 * write_bbt - [GENERIC] (Re)write the bad block table
470 * @mtd: MTD device structure
471 * @buf: temporary buffer
472 * @td: descriptor for the bad block table
473 * @md: descriptor for the bad block table mirror
474 * @chipsel: selector for a specific chip, -1 for all
476 * (Re)write the bad block table
479 static int write_bbt (struct mtd_info *mtd, uint8_t *buf,
480 struct nand_bbt_descr *td, struct nand_bbt_descr *md, int chipsel)
482 struct nand_chip *this = mtd->priv;
483 struct nand_oobinfo oobinfo;
484 struct erase_info einfo;
485 int i, j, res, chip = 0;
486 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
487 int nrchips, bbtoffs, pageoffs;
489 uint8_t rcode = td->reserved_block_code;
490 size_t retlen, len = 0;
495 /* Write bad block table per chip rather than per device ? */
496 if (td->options & NAND_BBT_PERCHIP) {
497 numblocks = (int) (this->chipsize >> this->bbt_erase_shift);
498 /* Full device write or specific chip ? */
500 nrchips = this->numchips;
502 nrchips = chipsel + 1;
506 numblocks = (int) (mtd->size >> this->bbt_erase_shift);
510 /* Loop through the chips */
511 for (; chip < nrchips; chip++) {
513 /* There was already a version of the table, reuse the page
514 * This applies for absolute placement too, as we have the
515 * page nr. in td->pages.
517 if (td->pages[chip] != -1) {
518 page = td->pages[chip];
522 /* Automatic placement of the bad block table */
523 /* Search direction top -> down ? */
524 if (td->options & NAND_BBT_LASTBLOCK) {
525 startblock = numblocks * (chip + 1) - 1;
528 startblock = chip * numblocks;
532 for (i = 0; i < td->maxblocks; i++) {
533 int block = startblock + dir * i;
534 /* Check, if the block is bad */
535 switch ((this->bbt[block >> 2] >> (2 * (block & 0x03))) & 0x03) {
540 page = block << (this->bbt_erase_shift - this->page_shift);
541 /* Check, if the block is used by the mirror table */
542 if (!md || md->pages[chip] != page)
545 printk (KERN_ERR "No space left to write bad block table\n");
549 /* Set up shift count and masks for the flash table */
550 bits = td->options & NAND_BBT_NRBITS_MSK;
552 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; msk[2] = ~rcode; msk[3] = 0x01; break;
553 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; msk[2] = ~rcode; msk[3] = 0x03; break;
554 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; msk[2] = ~rcode; msk[3] = 0x0f; break;
555 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; msk[2] = ~rcode; msk[3] = 0xff; break;
556 default: return -EINVAL;
559 bbtoffs = chip * (numblocks >> 2);
561 to = ((loff_t) page) << this->page_shift;
563 memcpy (&oobinfo, this->autooob, sizeof(oobinfo));
564 oobinfo.useecc = MTD_NANDECC_PLACEONLY;
566 /* Must we save the block contents ? */
567 if (td->options & NAND_BBT_SAVECONTENT) {
568 /* Make it block aligned */
569 to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1));
570 len = 1 << this->bbt_erase_shift;
571 res = mtd->read_ecc (mtd, to, len, &retlen, buf, &buf[len], &oobinfo);
574 printk (KERN_INFO "nand_bbt: Error reading block for writing the bad block table\n");
577 printk (KERN_WARNING "nand_bbt: ECC error while reading block for writing bad block table\n");
579 /* Calc the byte offset in the buffer */
580 pageoffs = page - (int)(to >> this->page_shift);
581 offs = pageoffs << this->page_shift;
582 /* Preset the bbt area with 0xff */
583 memset (&buf[offs], 0xff, (size_t)(numblocks >> sft));
584 /* Preset the bbt's oob area with 0xff */
585 memset (&buf[len + pageoffs * mtd->oobsize], 0xff,
586 ((len >> this->page_shift) - pageoffs) * mtd->oobsize);
587 if (td->options & NAND_BBT_VERSION) {
588 buf[len + (pageoffs * mtd->oobsize) + td->veroffs] = td->version[chip];
592 len = (size_t) (numblocks >> sft);
593 /* Make it page aligned ! */
594 len = (len + (mtd->oobblock-1)) & ~(mtd->oobblock-1);
595 /* Preset the buffer with 0xff */
596 memset (buf, 0xff, len + (len >> this->page_shift) * mtd->oobsize);
598 /* Pattern is located in oob area of first page */
599 memcpy (&buf[len + td->offs], td->pattern, td->len);
600 if (td->options & NAND_BBT_VERSION) {
601 buf[len + td->veroffs] = td->version[chip];
605 /* walk through the memory table */
606 for (i = 0; i < numblocks; ) {
608 dat = this->bbt[bbtoffs + (i >> 2)];
609 for (j = 0; j < 4; j++ , i++) {
610 int sftcnt = (i << (3 - sft)) & sftmsk;
611 /* Do not store the reserved bbt blocks ! */
612 buf[offs + (i >> sft)] &= ~(msk[dat & 0x03] << sftcnt);
617 memset (&einfo, 0, sizeof (einfo));
619 einfo.addr = (unsigned long) to;
620 einfo.len = 1 << this->bbt_erase_shift;
621 res = nand_erase_nand (mtd, &einfo, 1);
623 printk (KERN_WARNING "nand_bbt: Error during block erase: %d\n", res);
627 res = mtd->write_ecc (mtd, to, len, &retlen, buf, &buf[len], &oobinfo);
629 printk (KERN_WARNING "nand_bbt: Error while writing bad block table %d\n", res);
632 printk (KERN_DEBUG "Bad block table written to 0x%08x, version 0x%02X\n",
633 (unsigned int) to, td->version[chip]);
635 /* Mark it as used */
636 td->pages[chip] = page;
642 * nand_memory_bbt - [GENERIC] create a memory based bad block table
643 * @mtd: MTD device structure
644 * @bd: descriptor for the good/bad block search pattern
646 * The function creates a memory based bbt by scanning the device
647 * for manufacturer / software marked good / bad blocks
649 static inline int nand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd)
651 struct nand_chip *this = mtd->priv;
653 bd->options &= ~NAND_BBT_SCANEMPTY;
654 return create_bbt (mtd, this->data_buf, bd, -1);
658 * check_create - [GENERIC] create and write bbt(s) if neccecary
659 * @mtd: MTD device structure
660 * @buf: temporary buffer
661 * @bd: descriptor for the good/bad block search pattern
663 * The function checks the results of the previous call to read_bbt
664 * and creates / updates the bbt(s) if neccecary
665 * Creation is neccecary if no bbt was found for the chip/device
666 * Update is neccecary if one of the tables is missing or the
667 * version nr. of one table is less than the other
669 static int check_create (struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
671 int i, chips, writeops, chipsel, res;
672 struct nand_chip *this = mtd->priv;
673 struct nand_bbt_descr *td = this->bbt_td;
674 struct nand_bbt_descr *md = this->bbt_md;
675 struct nand_bbt_descr *rd, *rd2;
677 /* Do we have a bbt per chip ? */
678 if (td->options & NAND_BBT_PERCHIP)
679 chips = this->numchips;
683 for (i = 0; i < chips; i++) {
687 /* Per chip or per device ? */
688 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
689 /* Mirrored table avilable ? */
691 if (td->pages[i] == -1 && md->pages[i] == -1) {
696 if (td->pages[i] == -1) {
698 td->version[i] = md->version[i];
703 if (md->pages[i] == -1) {
705 md->version[i] = td->version[i];
710 if (td->version[i] == md->version[i]) {
712 if (!(td->options & NAND_BBT_VERSION))
717 if (((int8_t) (td->version[i] - md->version[i])) > 0) {
719 md->version[i] = td->version[i];
723 td->version[i] = md->version[i];
730 if (td->pages[i] == -1) {
738 /* Create the bad block table by scanning the device ? */
739 if (!(td->options & NAND_BBT_CREATE))
742 /* Create the table in memory by scanning the chip(s) */
743 create_bbt (mtd, buf, bd, chipsel);
749 /* read back first ? */
751 read_abs_bbt (mtd, buf, rd, chipsel);
752 /* If they weren't versioned, read both. */
754 read_abs_bbt (mtd, buf, rd2, chipsel);
756 /* Write the bad block table to the device ? */
757 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
758 res = write_bbt (mtd, buf, td, md, chipsel);
763 /* Write the mirror bad block table to the device ? */
764 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
765 res = write_bbt (mtd, buf, md, td, chipsel);
774 * mark_bbt_regions - [GENERIC] mark the bad block table regions
775 * @mtd: MTD device structure
776 * @td: bad block table descriptor
778 * The bad block table regions are marked as "bad" to prevent
779 * accidental erasures / writes. The regions are identified by
782 static void mark_bbt_region (struct mtd_info *mtd, struct nand_bbt_descr *td)
784 struct nand_chip *this = mtd->priv;
785 int i, j, chips, block, nrblocks, update;
786 uint8_t oldval, newval;
788 /* Do we have a bbt per chip ? */
789 if (td->options & NAND_BBT_PERCHIP) {
790 chips = this->numchips;
791 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
794 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
797 for (i = 0; i < chips; i++) {
798 if ((td->options & NAND_BBT_ABSPAGE) ||
799 !(td->options & NAND_BBT_WRITE)) {
800 if (td->pages[i] == -1) continue;
801 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
803 oldval = this->bbt[(block >> 3)];
804 newval = oldval | (0x2 << (block & 0x06));
805 this->bbt[(block >> 3)] = newval;
806 if ((oldval != newval) && td->reserved_block_code)
807 nand_update_bbt(mtd, block << (this->bbt_erase_shift - 1));
811 if (td->options & NAND_BBT_LASTBLOCK)
812 block = ((i + 1) * nrblocks) - td->maxblocks;
814 block = i * nrblocks;
816 for (j = 0; j < td->maxblocks; j++) {
817 oldval = this->bbt[(block >> 3)];
818 newval = oldval | (0x2 << (block & 0x06));
819 this->bbt[(block >> 3)] = newval;
820 if (oldval != newval) update = 1;
823 /* If we want reserved blocks to be recorded to flash, and some
824 new ones have been marked, then we need to update the stored
825 bbts. This should only happen once. */
826 if (update && td->reserved_block_code)
827 nand_update_bbt(mtd, (block - 2) << (this->bbt_erase_shift - 1));
832 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
833 * @mtd: MTD device structure
834 * @bd: descriptor for the good/bad block search pattern
836 * The function checks, if a bad block table(s) is/are already
837 * available. If not it scans the device for manufacturer
838 * marked good / bad blocks and writes the bad block table(s) to
839 * the selected place.
841 * The bad block table memory is allocated here. It must be freed
842 * by calling the nand_free_bbt function.
845 int nand_scan_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd)
847 struct nand_chip *this = mtd->priv;
850 struct nand_bbt_descr *td = this->bbt_td;
851 struct nand_bbt_descr *md = this->bbt_md;
853 len = mtd->size >> (this->bbt_erase_shift + 2);
854 /* Allocate memory (2bit per block) */
855 this->bbt = kmalloc (len, GFP_KERNEL);
857 printk (KERN_ERR "nand_scan_bbt: Out of memory\n");
860 /* Clear the memory bad block table */
861 memset (this->bbt, 0x00, len);
863 /* If no primary table decriptor is given, scan the device
864 * to build a memory based bad block table
867 if ((res = nand_memory_bbt(mtd, bd))) {
868 printk (KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n");
875 /* Allocate a temporary buffer for one eraseblock incl. oob */
876 len = (1 << this->bbt_erase_shift);
877 len += (len >> this->page_shift) * mtd->oobsize;
878 buf = kmalloc (len, GFP_KERNEL);
880 printk (KERN_ERR "nand_bbt: Out of memory\n");
886 /* Is the bbt at a given page ? */
887 if (td->options & NAND_BBT_ABSPAGE) {
888 res = read_abs_bbts (mtd, buf, td, md);
890 /* Search the bad block table using a pattern in oob */
891 res = search_read_bbts (mtd, buf, td, md);
895 res = check_create (mtd, buf, bd);
897 /* Prevent the bbt regions from erasing / writing */
898 mark_bbt_region (mtd, td);
900 mark_bbt_region (mtd, md);
908 * nand_update_bbt - [NAND Interface] update bad block table(s)
909 * @mtd: MTD device structure
910 * @offs: the offset of the newly marked block
912 * The function updates the bad block table(s)
914 int nand_update_bbt (struct mtd_info *mtd, loff_t offs)
916 struct nand_chip *this = mtd->priv;
917 int len, res = 0, writeops = 0;
920 struct nand_bbt_descr *td = this->bbt_td;
921 struct nand_bbt_descr *md = this->bbt_md;
923 if (!this->bbt || !td)
926 len = mtd->size >> (this->bbt_erase_shift + 2);
927 /* Allocate a temporary buffer for one eraseblock incl. oob */
928 len = (1 << this->bbt_erase_shift);
929 len += (len >> this->page_shift) * mtd->oobsize;
930 buf = kmalloc (len, GFP_KERNEL);
932 printk (KERN_ERR "nand_update_bbt: Out of memory\n");
936 writeops = md != NULL ? 0x03 : 0x01;
938 /* Do we have a bbt per chip ? */
939 if (td->options & NAND_BBT_PERCHIP) {
940 chip = (int) (offs >> this->chip_shift);
951 /* Write the bad block table to the device ? */
952 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
953 res = write_bbt (mtd, buf, td, md, chipsel);
957 /* Write the mirror bad block table to the device ? */
958 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
959 res = write_bbt (mtd, buf, md, td, chipsel);
967 /* Define some generic bad / good block scan pattern which are used
968 * while scanning a device for factory marked good / bad blocks. */
969 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
971 static struct nand_bbt_descr smallpage_memorybased = {
972 .options = NAND_BBT_SCAN2NDPAGE,
975 .pattern = scan_ff_pattern
978 static struct nand_bbt_descr largepage_memorybased = {
982 .pattern = scan_ff_pattern
985 static struct nand_bbt_descr smallpage_flashbased = {
986 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
989 .pattern = scan_ff_pattern
992 static struct nand_bbt_descr largepage_flashbased = {
993 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
996 .pattern = scan_ff_pattern
999 static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1001 static struct nand_bbt_descr agand_flashbased = {
1002 .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
1005 .pattern = scan_agand_pattern
1008 /* Generic flash bbt decriptors
1010 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1011 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1013 static struct nand_bbt_descr bbt_main_descr = {
1014 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1015 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1020 .pattern = bbt_pattern
1023 static struct nand_bbt_descr bbt_mirror_descr = {
1024 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1025 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1030 .pattern = mirror_pattern
1034 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1035 * @mtd: MTD device structure
1037 * This function selects the default bad block table
1038 * support for the device and calls the nand_scan_bbt function
1041 int nand_default_bbt (struct mtd_info *mtd)
1043 struct nand_chip *this = mtd->priv;
1045 /* Default for AG-AND. We must use a flash based
1046 * bad block table as the devices have factory marked
1047 * _good_ blocks. Erasing those blocks leads to loss
1048 * of the good / bad information, so we _must_ store
1049 * this information in a good / bad table during
1052 if (this->options & NAND_IS_AND) {
1053 /* Use the default pattern descriptors */
1054 if (!this->bbt_td) {
1055 this->bbt_td = &bbt_main_descr;
1056 this->bbt_md = &bbt_mirror_descr;
1058 this->options |= NAND_USE_FLASH_BBT;
1059 return nand_scan_bbt (mtd, &agand_flashbased);
1063 /* Is a flash based bad block table requested ? */
1064 if (this->options & NAND_USE_FLASH_BBT) {
1065 /* Use the default pattern descriptors */
1066 if (!this->bbt_td) {
1067 this->bbt_td = &bbt_main_descr;
1068 this->bbt_md = &bbt_mirror_descr;
1070 if (!this->badblock_pattern) {
1071 this->badblock_pattern = (mtd->oobblock > 512) ?
1072 &largepage_flashbased : &smallpage_flashbased;
1075 this->bbt_td = NULL;
1076 this->bbt_md = NULL;
1077 if (!this->badblock_pattern) {
1078 this->badblock_pattern = (mtd->oobblock > 512) ?
1079 &largepage_memorybased : &smallpage_memorybased;
1082 return nand_scan_bbt (mtd, this->badblock_pattern);
1086 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1087 * @mtd: MTD device structure
1088 * @offs: offset in the device
1089 * @allowbbt: allow access to bad block table region
1092 int nand_isbad_bbt (struct mtd_info *mtd, loff_t offs, int allowbbt)
1094 struct nand_chip *this = mtd->priv;
1098 /* Get block number * 2 */
1099 block = (int) (offs >> (this->bbt_erase_shift - 1));
1100 res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03;
1102 DEBUG (MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1103 (unsigned int)offs, block >> 1, res);
1106 case 0x00: return 0;
1107 case 0x01: return 1;
1108 case 0x02: return allowbbt ? 0 : 1;
1113 EXPORT_SYMBOL (nand_scan_bbt);
1114 EXPORT_SYMBOL (nand_default_bbt);