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1/*
2 * drivers/mtd/nand_bbt.c
3 *
4 * Overview:
5 * Bad block table support for the NAND driver
6 *
7 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * Description:
14 *
15 * When nand_scan_bbt is called, then it tries to find the bad block table
16 * depending on the options in the BBT descriptor(s). If no flash based BBT
17 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
18 * marked good / bad blocks. This information is used to create a memory BBT.
19 * Once a new bad block is discovered then the "factory" information is updated
20 * on the device.
21 * If a flash based BBT is specified then the function first tries to find the
22 * BBT on flash. If a BBT is found then the contents are read and the memory
23 * based BBT is created. If a mirrored BBT is selected then the mirror is
24 * searched too and the versions are compared. If the mirror has a greater
25 * version number, then the mirror BBT is used to build the memory based BBT.
26 * If the tables are not versioned, then we "or" the bad block information.
27 * If one of the BBTs is out of date or does not exist it is (re)created.
28 * If no BBT exists at all then the device is scanned for factory marked
29 * good / bad blocks and the bad block tables are created.
30 *
31 * For manufacturer created BBTs like the one found on M-SYS DOC devices
32 * the BBT is searched and read but never created
33 *
34 * The auto generated bad block table is located in the last good blocks
35 * of the device. The table is mirrored, so it can be updated eventually.
36 * The table is marked in the OOB area with an ident pattern and a version
37 * number which indicates which of both tables is more up to date. If the NAND
38 * controller needs the complete OOB area for the ECC information then the
39 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
40 * course): it moves the ident pattern and the version byte into the data area
41 * and the OOB area will remain untouched.
42 *
43 * The table uses 2 bits per block
44 * 11b: block is good
45 * 00b: block is factory marked bad
46 * 01b, 10b: block is marked bad due to wear
47 *
48 * The memory bad block table uses the following scheme:
49 * 00b: block is good
50 * 01b: block is marked bad due to wear
51 * 10b: block is reserved (to protect the bbt area)
52 * 11b: block is factory marked bad
53 *
54 * Multichip devices like DOC store the bad block info per floor.
55 *
56 * Following assumptions are made:
57 * - bbts start at a page boundary, if autolocated on a block boundary
58 * - the space necessary for a bbt in FLASH does not exceed a block boundary
59 *
60 */
61
62#include <linux/slab.h>
63#include <linux/types.h>
64#include <linux/mtd/mtd.h>
65#include <linux/mtd/bbm.h>
66#include <linux/mtd/nand.h>
67#include <linux/mtd/nand_ecc.h>
68#include <linux/bitops.h>
69#include <linux/delay.h>
70#include <linux/vmalloc.h>
71#include <linux/export.h>
72#include <linux/string.h>
73
74#define BBT_BLOCK_GOOD 0x00
75#define BBT_BLOCK_WORN 0x01
76#define BBT_BLOCK_RESERVED 0x02
77#define BBT_BLOCK_FACTORY_BAD 0x03
78
79#define BBT_ENTRY_MASK 0x03
80#define BBT_ENTRY_SHIFT 2
81
82static int nand_update_bbt(struct mtd_info *mtd, loff_t offs);
83
84static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)
85{
86 uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];
87 entry >>= (block & BBT_ENTRY_MASK) * 2;
88 return entry & BBT_ENTRY_MASK;
89}
90
91static inline void bbt_mark_entry(struct nand_chip *chip, int block,
92 uint8_t mark)
93{
94 uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
95 chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
96}
97
98static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
99{
100 if (memcmp(buf, td->pattern, td->len))
101 return -1;
102 return 0;
103}
104
105/**
106 * check_pattern - [GENERIC] check if a pattern is in the buffer
107 * @buf: the buffer to search
108 * @len: the length of buffer to search
109 * @paglen: the pagelength
110 * @td: search pattern descriptor
111 *
112 * Check for a pattern at the given place. Used to search bad block tables and
113 * good / bad block identifiers.
114 */
115static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
116{
117 if (td->options & NAND_BBT_NO_OOB)
118 return check_pattern_no_oob(buf, td);
119
120 /* Compare the pattern */
121 if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
122 return -1;
123
124 return 0;
125}
126
127/**
128 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
129 * @buf: the buffer to search
130 * @td: search pattern descriptor
131 *
132 * Check for a pattern at the given place. Used to search bad block tables and
133 * good / bad block identifiers. Same as check_pattern, but no optional empty
134 * check.
135 */
136static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
137{
138 /* Compare the pattern */
139 if (memcmp(buf + td->offs, td->pattern, td->len))
140 return -1;
141 return 0;
142}
143
144/**
145 * add_marker_len - compute the length of the marker in data area
146 * @td: BBT descriptor used for computation
147 *
148 * The length will be 0 if the marker is located in OOB area.
149 */
150static u32 add_marker_len(struct nand_bbt_descr *td)
151{
152 u32 len;
153
154 if (!(td->options & NAND_BBT_NO_OOB))
155 return 0;
156
157 len = td->len;
158 if (td->options & NAND_BBT_VERSION)
159 len++;
160 return len;
161}
162
163/**
164 * read_bbt - [GENERIC] Read the bad block table starting from page
165 * @mtd: MTD device structure
166 * @buf: temporary buffer
167 * @page: the starting page
168 * @num: the number of bbt descriptors to read
169 * @td: the bbt describtion table
170 * @offs: block number offset in the table
171 *
172 * Read the bad block table starting from page.
173 */
174static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
175 struct nand_bbt_descr *td, int offs)
176{
177 int res, ret = 0, i, j, act = 0;
178 struct nand_chip *this = mtd->priv;
179 size_t retlen, len, totlen;
180 loff_t from;
181 int bits = td->options & NAND_BBT_NRBITS_MSK;
182 uint8_t msk = (uint8_t)((1 << bits) - 1);
183 u32 marker_len;
184 int reserved_block_code = td->reserved_block_code;
185
186 totlen = (num * bits) >> 3;
187 marker_len = add_marker_len(td);
188 from = ((loff_t)page) << this->page_shift;
189
190 while (totlen) {
191 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
192 if (marker_len) {
193 /*
194 * In case the BBT marker is not in the OOB area it
195 * will be just in the first page.
196 */
197 len -= marker_len;
198 from += marker_len;
199 marker_len = 0;
200 }
201 res = mtd_read(mtd, from, len, &retlen, buf);
202 if (res < 0) {
203 if (mtd_is_eccerr(res)) {
204 pr_info("nand_bbt: ECC error in BBT at "
205 "0x%012llx\n", from & ~mtd->writesize);
206 return res;
207 } else if (mtd_is_bitflip(res)) {
208 pr_info("nand_bbt: corrected error in BBT at "
209 "0x%012llx\n", from & ~mtd->writesize);
210 ret = res;
211 } else {
212 pr_info("nand_bbt: error reading BBT\n");
213 return res;
214 }
215 }
216
217 /* Analyse data */
218 for (i = 0; i < len; i++) {
219 uint8_t dat = buf[i];
220 for (j = 0; j < 8; j += bits, act++) {
221 uint8_t tmp = (dat >> j) & msk;
222 if (tmp == msk)
223 continue;
224 if (reserved_block_code && (tmp == reserved_block_code)) {
225 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
226 (loff_t)(offs + act) <<
227 this->bbt_erase_shift);
228 bbt_mark_entry(this, offs + act,
229 BBT_BLOCK_RESERVED);
230 mtd->ecc_stats.bbtblocks++;
231 continue;
232 }
233 /*
234 * Leave it for now, if it's matured we can
235 * move this message to pr_debug.
236 */
237 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
238 (loff_t)(offs + act) <<
239 this->bbt_erase_shift);
240 /* Factory marked bad or worn out? */
241 if (tmp == 0)
242 bbt_mark_entry(this, offs + act,
243 BBT_BLOCK_FACTORY_BAD);
244 else
245 bbt_mark_entry(this, offs + act,
246 BBT_BLOCK_WORN);
247 mtd->ecc_stats.badblocks++;
248 }
249 }
250 totlen -= len;
251 from += len;
252 }
253 return ret;
254}
255
256/**
257 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
258 * @mtd: MTD device structure
259 * @buf: temporary buffer
260 * @td: descriptor for the bad block table
261 * @chip: read the table for a specific chip, -1 read all chips; applies only if
262 * NAND_BBT_PERCHIP option is set
263 *
264 * Read the bad block table for all chips starting at a given page. We assume
265 * that the bbt bits are in consecutive order.
266 */
267static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
268{
269 struct nand_chip *this = mtd->priv;
270 int res = 0, i;
271
272 if (td->options & NAND_BBT_PERCHIP) {
273 int offs = 0;
274 for (i = 0; i < this->numchips; i++) {
275 if (chip == -1 || chip == i)
276 res = read_bbt(mtd, buf, td->pages[i],
277 this->chipsize >> this->bbt_erase_shift,
278 td, offs);
279 if (res)
280 return res;
281 offs += this->chipsize >> this->bbt_erase_shift;
282 }
283 } else {
284 res = read_bbt(mtd, buf, td->pages[0],
285 mtd->size >> this->bbt_erase_shift, td, 0);
286 if (res)
287 return res;
288 }
289 return 0;
290}
291
292/* BBT marker is in the first page, no OOB */
293static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
294 struct nand_bbt_descr *td)
295{
296 size_t retlen;
297 size_t len;
298
299 len = td->len;
300 if (td->options & NAND_BBT_VERSION)
301 len++;
302
303 return mtd_read(mtd, offs, len, &retlen, buf);
304}
305
306/**
307 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
308 * @mtd: MTD device structure
309 * @buf: temporary buffer
310 * @offs: offset at which to scan
311 * @len: length of data region to read
312 *
313 * Scan read data from data+OOB. May traverse multiple pages, interleaving
314 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
315 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
316 */
317static int scan_read_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
318 size_t len)
319{
320 struct mtd_oob_ops ops;
321 int res, ret = 0;
322
323 ops.mode = MTD_OPS_PLACE_OOB;
324 ops.ooboffs = 0;
325 ops.ooblen = mtd->oobsize;
326
327 while (len > 0) {
328 ops.datbuf = buf;
329 ops.len = min(len, (size_t)mtd->writesize);
330 ops.oobbuf = buf + ops.len;
331
332 res = mtd_read_oob(mtd, offs, &ops);
333 if (res) {
334 if (!mtd_is_bitflip_or_eccerr(res))
335 return res;
336 else if (mtd_is_eccerr(res) || !ret)
337 ret = res;
338 }
339
340 buf += mtd->oobsize + mtd->writesize;
341 len -= mtd->writesize;
342 offs += mtd->writesize;
343 }
344 return ret;
345}
346
347static int scan_read(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
348 size_t len, struct nand_bbt_descr *td)
349{
350 if (td->options & NAND_BBT_NO_OOB)
351 return scan_read_data(mtd, buf, offs, td);
352 else
353 return scan_read_oob(mtd, buf, offs, len);
354}
355
356/* Scan write data with oob to flash */
357static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
358 uint8_t *buf, uint8_t *oob)
359{
360 struct mtd_oob_ops ops;
361
362 ops.mode = MTD_OPS_PLACE_OOB;
363 ops.ooboffs = 0;
364 ops.ooblen = mtd->oobsize;
365 ops.datbuf = buf;
366 ops.oobbuf = oob;
367 ops.len = len;
368
369 return mtd_write_oob(mtd, offs, &ops);
370}
371
372static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
373{
374 u32 ver_offs = td->veroffs;
375
376 if (!(td->options & NAND_BBT_NO_OOB))
377 ver_offs += mtd->writesize;
378 return ver_offs;
379}
380
381/**
382 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
383 * @mtd: MTD device structure
384 * @buf: temporary buffer
385 * @td: descriptor for the bad block table
386 * @md: descriptor for the bad block table mirror
387 *
388 * Read the bad block table(s) for all chips starting at a given page. We
389 * assume that the bbt bits are in consecutive order.
390 */
391static void read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
392 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
393{
394 struct nand_chip *this = mtd->priv;
395
396 /* Read the primary version, if available */
397 if (td->options & NAND_BBT_VERSION) {
398 scan_read(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
399 mtd->writesize, td);
400 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
401 pr_info("Bad block table at page %d, version 0x%02X\n",
402 td->pages[0], td->version[0]);
403 }
404
405 /* Read the mirror version, if available */
406 if (md && (md->options & NAND_BBT_VERSION)) {
407 scan_read(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
408 mtd->writesize, md);
409 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
410 pr_info("Bad block table at page %d, version 0x%02X\n",
411 md->pages[0], md->version[0]);
412 }
413}
414
415/* Scan a given block partially */
416static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
417 loff_t offs, uint8_t *buf, int numpages)
418{
419 struct mtd_oob_ops ops;
420 int j, ret;
421
422 ops.ooblen = mtd->oobsize;
423 ops.oobbuf = buf;
424 ops.ooboffs = 0;
425 ops.datbuf = NULL;
426 ops.mode = MTD_OPS_PLACE_OOB;
427
428 for (j = 0; j < numpages; j++) {
429 /*
430 * Read the full oob until read_oob is fixed to handle single
431 * byte reads for 16 bit buswidth.
432 */
433 ret = mtd_read_oob(mtd, offs, &ops);
434 /* Ignore ECC errors when checking for BBM */
435 if (ret && !mtd_is_bitflip_or_eccerr(ret))
436 return ret;
437
438 if (check_short_pattern(buf, bd))
439 return 1;
440
441 offs += mtd->writesize;
442 }
443 return 0;
444}
445
446/**
447 * create_bbt - [GENERIC] Create a bad block table by scanning the device
448 * @mtd: MTD device structure
449 * @buf: temporary buffer
450 * @bd: descriptor for the good/bad block search pattern
451 * @chip: create the table for a specific chip, -1 read all chips; applies only
452 * if NAND_BBT_PERCHIP option is set
453 *
454 * Create a bad block table by scanning the device for the given good/bad block
455 * identify pattern.
456 */
457static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
458 struct nand_bbt_descr *bd, int chip)
459{
460 struct nand_chip *this = mtd->priv;
461 int i, numblocks, numpages;
462 int startblock;
463 loff_t from;
464
465 pr_info("Scanning device for bad blocks\n");
466
467 if (bd->options & NAND_BBT_SCAN2NDPAGE)
468 numpages = 2;
469 else
470 numpages = 1;
471
472 if (chip == -1) {
473 numblocks = mtd->size >> this->bbt_erase_shift;
474 startblock = 0;
475 from = 0;
476 } else {
477 if (chip >= this->numchips) {
478 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
479 chip + 1, this->numchips);
480 return -EINVAL;
481 }
482 numblocks = this->chipsize >> this->bbt_erase_shift;
483 startblock = chip * numblocks;
484 numblocks += startblock;
485 from = (loff_t)startblock << this->bbt_erase_shift;
486 }
487
488 if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
489 from += mtd->erasesize - (mtd->writesize * numpages);
490
491 for (i = startblock; i < numblocks; i++) {
492 int ret;
493
494 BUG_ON(bd->options & NAND_BBT_NO_OOB);
495
496 ret = scan_block_fast(mtd, bd, from, buf, numpages);
497 if (ret < 0)
498 return ret;
499
500 if (ret) {
501 bbt_mark_entry(this, i, BBT_BLOCK_FACTORY_BAD);
502 pr_warn("Bad eraseblock %d at 0x%012llx\n",
503 i, (unsigned long long)from);
504 mtd->ecc_stats.badblocks++;
505 }
506
507 from += (1 << this->bbt_erase_shift);
508 }
509 return 0;
510}
511
512/**
513 * search_bbt - [GENERIC] scan the device for a specific bad block table
514 * @mtd: MTD device structure
515 * @buf: temporary buffer
516 * @td: descriptor for the bad block table
517 *
518 * Read the bad block table by searching for a given ident pattern. Search is
519 * preformed either from the beginning up or from the end of the device
520 * downwards. The search starts always at the start of a block. If the option
521 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
522 * the bad block information of this chip. This is necessary to provide support
523 * for certain DOC devices.
524 *
525 * The bbt ident pattern resides in the oob area of the first page in a block.
526 */
527static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
528{
529 struct nand_chip *this = mtd->priv;
530 int i, chips;
531 int bits, startblock, block, dir;
532 int scanlen = mtd->writesize + mtd->oobsize;
533 int bbtblocks;
534 int blocktopage = this->bbt_erase_shift - this->page_shift;
535
536 /* Search direction top -> down? */
537 if (td->options & NAND_BBT_LASTBLOCK) {
538 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
539 dir = -1;
540 } else {
541 startblock = 0;
542 dir = 1;
543 }
544
545 /* Do we have a bbt per chip? */
546 if (td->options & NAND_BBT_PERCHIP) {
547 chips = this->numchips;
548 bbtblocks = this->chipsize >> this->bbt_erase_shift;
549 startblock &= bbtblocks - 1;
550 } else {
551 chips = 1;
552 bbtblocks = mtd->size >> this->bbt_erase_shift;
553 }
554
555 /* Number of bits for each erase block in the bbt */
556 bits = td->options & NAND_BBT_NRBITS_MSK;
557
558 for (i = 0; i < chips; i++) {
559 /* Reset version information */
560 td->version[i] = 0;
561 td->pages[i] = -1;
562 /* Scan the maximum number of blocks */
563 for (block = 0; block < td->maxblocks; block++) {
564
565 int actblock = startblock + dir * block;
566 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
567
568 /* Read first page */
569 scan_read(mtd, buf, offs, mtd->writesize, td);
570 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
571 td->pages[i] = actblock << blocktopage;
572 if (td->options & NAND_BBT_VERSION) {
573 offs = bbt_get_ver_offs(mtd, td);
574 td->version[i] = buf[offs];
575 }
576 break;
577 }
578 }
579 startblock += this->chipsize >> this->bbt_erase_shift;
580 }
581 /* Check, if we found a bbt for each requested chip */
582 for (i = 0; i < chips; i++) {
583 if (td->pages[i] == -1)
584 pr_warn("Bad block table not found for chip %d\n", i);
585 else
586 pr_info("Bad block table found at page %d, version "
587 "0x%02X\n", td->pages[i], td->version[i]);
588 }
589 return 0;
590}
591
592/**
593 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
594 * @mtd: MTD device structure
595 * @buf: temporary buffer
596 * @td: descriptor for the bad block table
597 * @md: descriptor for the bad block table mirror
598 *
599 * Search and read the bad block table(s).
600 */
601static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf,
602 struct nand_bbt_descr *td,
603 struct nand_bbt_descr *md)
604{
605 /* Search the primary table */
606 search_bbt(mtd, buf, td);
607
608 /* Search the mirror table */
609 if (md)
610 search_bbt(mtd, buf, md);
611}
612
613/**
614 * write_bbt - [GENERIC] (Re)write the bad block table
615 * @mtd: MTD device structure
616 * @buf: temporary buffer
617 * @td: descriptor for the bad block table
618 * @md: descriptor for the bad block table mirror
619 * @chipsel: selector for a specific chip, -1 for all
620 *
621 * (Re)write the bad block table.
622 */
623static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
624 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
625 int chipsel)
626{
627 struct nand_chip *this = mtd->priv;
628 struct erase_info einfo;
629 int i, res, chip = 0;
630 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
631 int nrchips, pageoffs, ooboffs;
632 uint8_t msk[4];
633 uint8_t rcode = td->reserved_block_code;
634 size_t retlen, len = 0;
635 loff_t to;
636 struct mtd_oob_ops ops;
637
638 ops.ooblen = mtd->oobsize;
639 ops.ooboffs = 0;
640 ops.datbuf = NULL;
641 ops.mode = MTD_OPS_PLACE_OOB;
642
643 if (!rcode)
644 rcode = 0xff;
645 /* Write bad block table per chip rather than per device? */
646 if (td->options & NAND_BBT_PERCHIP) {
647 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
648 /* Full device write or specific chip? */
649 if (chipsel == -1) {
650 nrchips = this->numchips;
651 } else {
652 nrchips = chipsel + 1;
653 chip = chipsel;
654 }
655 } else {
656 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
657 nrchips = 1;
658 }
659
660 /* Loop through the chips */
661 for (; chip < nrchips; chip++) {
662 /*
663 * There was already a version of the table, reuse the page
664 * This applies for absolute placement too, as we have the
665 * page nr. in td->pages.
666 */
667 if (td->pages[chip] != -1) {
668 page = td->pages[chip];
669 goto write;
670 }
671
672 /*
673 * Automatic placement of the bad block table. Search direction
674 * top -> down?
675 */
676 if (td->options & NAND_BBT_LASTBLOCK) {
677 startblock = numblocks * (chip + 1) - 1;
678 dir = -1;
679 } else {
680 startblock = chip * numblocks;
681 dir = 1;
682 }
683
684 for (i = 0; i < td->maxblocks; i++) {
685 int block = startblock + dir * i;
686 /* Check, if the block is bad */
687 switch (bbt_get_entry(this, block)) {
688 case BBT_BLOCK_WORN:
689 case BBT_BLOCK_FACTORY_BAD:
690 continue;
691 }
692 page = block <<
693 (this->bbt_erase_shift - this->page_shift);
694 /* Check, if the block is used by the mirror table */
695 if (!md || md->pages[chip] != page)
696 goto write;
697 }
698 pr_err("No space left to write bad block table\n");
699 return -ENOSPC;
700 write:
701
702 /* Set up shift count and masks for the flash table */
703 bits = td->options & NAND_BBT_NRBITS_MSK;
704 msk[2] = ~rcode;
705 switch (bits) {
706 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
707 msk[3] = 0x01;
708 break;
709 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
710 msk[3] = 0x03;
711 break;
712 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
713 msk[3] = 0x0f;
714 break;
715 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
716 msk[3] = 0xff;
717 break;
718 default: return -EINVAL;
719 }
720
721 to = ((loff_t)page) << this->page_shift;
722
723 /* Must we save the block contents? */
724 if (td->options & NAND_BBT_SAVECONTENT) {
725 /* Make it block aligned */
726 to &= ~((loff_t)((1 << this->bbt_erase_shift) - 1));
727 len = 1 << this->bbt_erase_shift;
728 res = mtd_read(mtd, to, len, &retlen, buf);
729 if (res < 0) {
730 if (retlen != len) {
731 pr_info("nand_bbt: error reading block "
732 "for writing the bad block table\n");
733 return res;
734 }
735 pr_warn("nand_bbt: ECC error while reading "
736 "block for writing bad block table\n");
737 }
738 /* Read oob data */
739 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
740 ops.oobbuf = &buf[len];
741 res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
742 if (res < 0 || ops.oobretlen != ops.ooblen)
743 goto outerr;
744
745 /* Calc the byte offset in the buffer */
746 pageoffs = page - (int)(to >> this->page_shift);
747 offs = pageoffs << this->page_shift;
748 /* Preset the bbt area with 0xff */
749 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
750 ooboffs = len + (pageoffs * mtd->oobsize);
751
752 } else if (td->options & NAND_BBT_NO_OOB) {
753 ooboffs = 0;
754 offs = td->len;
755 /* The version byte */
756 if (td->options & NAND_BBT_VERSION)
757 offs++;
758 /* Calc length */
759 len = (size_t)(numblocks >> sft);
760 len += offs;
761 /* Make it page aligned! */
762 len = ALIGN(len, mtd->writesize);
763 /* Preset the buffer with 0xff */
764 memset(buf, 0xff, len);
765 /* Pattern is located at the begin of first page */
766 memcpy(buf, td->pattern, td->len);
767 } else {
768 /* Calc length */
769 len = (size_t)(numblocks >> sft);
770 /* Make it page aligned! */
771 len = ALIGN(len, mtd->writesize);
772 /* Preset the buffer with 0xff */
773 memset(buf, 0xff, len +
774 (len >> this->page_shift)* mtd->oobsize);
775 offs = 0;
776 ooboffs = len;
777 /* Pattern is located in oob area of first page */
778 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
779 }
780
781 if (td->options & NAND_BBT_VERSION)
782 buf[ooboffs + td->veroffs] = td->version[chip];
783
784 /* Walk through the memory table */
785 for (i = 0; i < numblocks; i++) {
786 uint8_t dat;
787 int sftcnt = (i << (3 - sft)) & sftmsk;
788 dat = bbt_get_entry(this, chip * numblocks + i);
789 /* Do not store the reserved bbt blocks! */
790 buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
791 }
792
793 memset(&einfo, 0, sizeof(einfo));
794 einfo.mtd = mtd;
795 einfo.addr = to;
796 einfo.len = 1 << this->bbt_erase_shift;
797 res = nand_erase_nand(mtd, &einfo, 1);
798 if (res < 0)
799 goto outerr;
800
801 res = scan_write_bbt(mtd, to, len, buf,
802 td->options & NAND_BBT_NO_OOB ? NULL :
803 &buf[len]);
804 if (res < 0)
805 goto outerr;
806
807 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
808 (unsigned long long)to, td->version[chip]);
809
810 /* Mark it as used */
811 td->pages[chip] = page;
812 }
813 return 0;
814
815 outerr:
816 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
817 return res;
818}
819
820/**
821 * nand_memory_bbt - [GENERIC] create a memory based bad block table
822 * @mtd: MTD device structure
823 * @bd: descriptor for the good/bad block search pattern
824 *
825 * The function creates a memory based bbt by scanning the device for
826 * manufacturer / software marked good / bad blocks.
827 */
828static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
829{
830 struct nand_chip *this = mtd->priv;
831
832 return create_bbt(mtd, this->buffers->databuf, bd, -1);
833}
834
835/**
836 * check_create - [GENERIC] create and write bbt(s) if necessary
837 * @mtd: MTD device structure
838 * @buf: temporary buffer
839 * @bd: descriptor for the good/bad block search pattern
840 *
841 * The function checks the results of the previous call to read_bbt and creates
842 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
843 * for the chip/device. Update is necessary if one of the tables is missing or
844 * the version nr. of one table is less than the other.
845 */
846static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
847{
848 int i, chips, writeops, create, chipsel, res, res2;
849 struct nand_chip *this = mtd->priv;
850 struct nand_bbt_descr *td = this->bbt_td;
851 struct nand_bbt_descr *md = this->bbt_md;
852 struct nand_bbt_descr *rd, *rd2;
853
854 /* Do we have a bbt per chip? */
855 if (td->options & NAND_BBT_PERCHIP)
856 chips = this->numchips;
857 else
858 chips = 1;
859
860 for (i = 0; i < chips; i++) {
861 writeops = 0;
862 create = 0;
863 rd = NULL;
864 rd2 = NULL;
865 res = res2 = 0;
866 /* Per chip or per device? */
867 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
868 /* Mirrored table available? */
869 if (md) {
870 if (td->pages[i] == -1 && md->pages[i] == -1) {
871 create = 1;
872 writeops = 0x03;
873 } else if (td->pages[i] == -1) {
874 rd = md;
875 writeops = 0x01;
876 } else if (md->pages[i] == -1) {
877 rd = td;
878 writeops = 0x02;
879 } else if (td->version[i] == md->version[i]) {
880 rd = td;
881 if (!(td->options & NAND_BBT_VERSION))
882 rd2 = md;
883 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
884 rd = td;
885 writeops = 0x02;
886 } else {
887 rd = md;
888 writeops = 0x01;
889 }
890 } else {
891 if (td->pages[i] == -1) {
892 create = 1;
893 writeops = 0x01;
894 } else {
895 rd = td;
896 }
897 }
898
899 if (create) {
900 /* Create the bad block table by scanning the device? */
901 if (!(td->options & NAND_BBT_CREATE))
902 continue;
903
904 /* Create the table in memory by scanning the chip(s) */
905 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
906 create_bbt(mtd, buf, bd, chipsel);
907
908 td->version[i] = 1;
909 if (md)
910 md->version[i] = 1;
911 }
912
913 /* Read back first? */
914 if (rd) {
915 res = read_abs_bbt(mtd, buf, rd, chipsel);
916 if (mtd_is_eccerr(res)) {
917 /* Mark table as invalid */
918 rd->pages[i] = -1;
919 rd->version[i] = 0;
920 i--;
921 continue;
922 }
923 }
924 /* If they weren't versioned, read both */
925 if (rd2) {
926 res2 = read_abs_bbt(mtd, buf, rd2, chipsel);
927 if (mtd_is_eccerr(res2)) {
928 /* Mark table as invalid */
929 rd2->pages[i] = -1;
930 rd2->version[i] = 0;
931 i--;
932 continue;
933 }
934 }
935
936 /* Scrub the flash table(s)? */
937 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
938 writeops = 0x03;
939
940 /* Update version numbers before writing */
941 if (md) {
942 td->version[i] = max(td->version[i], md->version[i]);
943 md->version[i] = td->version[i];
944 }
945
946 /* Write the bad block table to the device? */
947 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
948 res = write_bbt(mtd, buf, td, md, chipsel);
949 if (res < 0)
950 return res;
951 }
952
953 /* Write the mirror bad block table to the device? */
954 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
955 res = write_bbt(mtd, buf, md, td, chipsel);
956 if (res < 0)
957 return res;
958 }
959 }
960 return 0;
961}
962
963/**
964 * mark_bbt_regions - [GENERIC] mark the bad block table regions
965 * @mtd: MTD device structure
966 * @td: bad block table descriptor
967 *
968 * The bad block table regions are marked as "bad" to prevent accidental
969 * erasures / writes. The regions are identified by the mark 0x02.
970 */
971static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
972{
973 struct nand_chip *this = mtd->priv;
974 int i, j, chips, block, nrblocks, update;
975 uint8_t oldval;
976
977 /* Do we have a bbt per chip? */
978 if (td->options & NAND_BBT_PERCHIP) {
979 chips = this->numchips;
980 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
981 } else {
982 chips = 1;
983 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
984 }
985
986 for (i = 0; i < chips; i++) {
987 if ((td->options & NAND_BBT_ABSPAGE) ||
988 !(td->options & NAND_BBT_WRITE)) {
989 if (td->pages[i] == -1)
990 continue;
991 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
992 oldval = bbt_get_entry(this, block);
993 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
994 if ((oldval != BBT_BLOCK_RESERVED) &&
995 td->reserved_block_code)
996 nand_update_bbt(mtd, (loff_t)block <<
997 this->bbt_erase_shift);
998 continue;
999 }
1000 update = 0;
1001 if (td->options & NAND_BBT_LASTBLOCK)
1002 block = ((i + 1) * nrblocks) - td->maxblocks;
1003 else
1004 block = i * nrblocks;
1005 for (j = 0; j < td->maxblocks; j++) {
1006 oldval = bbt_get_entry(this, block);
1007 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1008 if (oldval != BBT_BLOCK_RESERVED)
1009 update = 1;
1010 block++;
1011 }
1012 /*
1013 * If we want reserved blocks to be recorded to flash, and some
1014 * new ones have been marked, then we need to update the stored
1015 * bbts. This should only happen once.
1016 */
1017 if (update && td->reserved_block_code)
1018 nand_update_bbt(mtd, (loff_t)(block - 1) <<
1019 this->bbt_erase_shift);
1020 }
1021}
1022
1023/**
1024 * verify_bbt_descr - verify the bad block description
1025 * @mtd: MTD device structure
1026 * @bd: the table to verify
1027 *
1028 * This functions performs a few sanity checks on the bad block description
1029 * table.
1030 */
1031static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1032{
1033 struct nand_chip *this = mtd->priv;
1034 u32 pattern_len;
1035 u32 bits;
1036 u32 table_size;
1037
1038 if (!bd)
1039 return;
1040
1041 pattern_len = bd->len;
1042 bits = bd->options & NAND_BBT_NRBITS_MSK;
1043
1044 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1045 !(this->bbt_options & NAND_BBT_USE_FLASH));
1046 BUG_ON(!bits);
1047
1048 if (bd->options & NAND_BBT_VERSION)
1049 pattern_len++;
1050
1051 if (bd->options & NAND_BBT_NO_OOB) {
1052 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1053 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1054 BUG_ON(bd->offs);
1055 if (bd->options & NAND_BBT_VERSION)
1056 BUG_ON(bd->veroffs != bd->len);
1057 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1058 }
1059
1060 if (bd->options & NAND_BBT_PERCHIP)
1061 table_size = this->chipsize >> this->bbt_erase_shift;
1062 else
1063 table_size = mtd->size >> this->bbt_erase_shift;
1064 table_size >>= 3;
1065 table_size *= bits;
1066 if (bd->options & NAND_BBT_NO_OOB)
1067 table_size += pattern_len;
1068 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1069}
1070
1071/**
1072 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1073 * @mtd: MTD device structure
1074 * @bd: descriptor for the good/bad block search pattern
1075 *
1076 * The function checks, if a bad block table(s) is/are already available. If
1077 * not it scans the device for manufacturer marked good / bad blocks and writes
1078 * the bad block table(s) to the selected place.
1079 *
1080 * The bad block table memory is allocated here. It must be freed by calling
1081 * the nand_free_bbt function.
1082 */
1083int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1084{
1085 struct nand_chip *this = mtd->priv;
1086 int len, res = 0;
1087 uint8_t *buf;
1088 struct nand_bbt_descr *td = this->bbt_td;
1089 struct nand_bbt_descr *md = this->bbt_md;
1090
1091 len = mtd->size >> (this->bbt_erase_shift + 2);
1092 /*
1093 * Allocate memory (2bit per block) and clear the memory bad block
1094 * table.
1095 */
1096 this->bbt = kzalloc(len, GFP_KERNEL);
1097 if (!this->bbt)
1098 return -ENOMEM;
1099
1100 /*
1101 * If no primary table decriptor is given, scan the device to build a
1102 * memory based bad block table.
1103 */
1104 if (!td) {
1105 if ((res = nand_memory_bbt(mtd, bd))) {
1106 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1107 kfree(this->bbt);
1108 this->bbt = NULL;
1109 }
1110 return res;
1111 }
1112 verify_bbt_descr(mtd, td);
1113 verify_bbt_descr(mtd, md);
1114
1115 /* Allocate a temporary buffer for one eraseblock incl. oob */
1116 len = (1 << this->bbt_erase_shift);
1117 len += (len >> this->page_shift) * mtd->oobsize;
1118 buf = vmalloc(len);
1119 if (!buf) {
1120 kfree(this->bbt);
1121 this->bbt = NULL;
1122 return -ENOMEM;
1123 }
1124
1125 /* Is the bbt at a given page? */
1126 if (td->options & NAND_BBT_ABSPAGE) {
1127 read_abs_bbts(mtd, buf, td, md);
1128 } else {
1129 /* Search the bad block table using a pattern in oob */
1130 search_read_bbts(mtd, buf, td, md);
1131 }
1132
1133 res = check_create(mtd, buf, bd);
1134
1135 /* Prevent the bbt regions from erasing / writing */
1136 mark_bbt_region(mtd, td);
1137 if (md)
1138 mark_bbt_region(mtd, md);
1139
1140 vfree(buf);
1141 return res;
1142}
1143
1144/**
1145 * nand_update_bbt - update bad block table(s)
1146 * @mtd: MTD device structure
1147 * @offs: the offset of the newly marked block
1148 *
1149 * The function updates the bad block table(s).
1150 */
1151static int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1152{
1153 struct nand_chip *this = mtd->priv;
1154 int len, res = 0;
1155 int chip, chipsel;
1156 uint8_t *buf;
1157 struct nand_bbt_descr *td = this->bbt_td;
1158 struct nand_bbt_descr *md = this->bbt_md;
1159
1160 if (!this->bbt || !td)
1161 return -EINVAL;
1162
1163 /* Allocate a temporary buffer for one eraseblock incl. oob */
1164 len = (1 << this->bbt_erase_shift);
1165 len += (len >> this->page_shift) * mtd->oobsize;
1166 buf = kmalloc(len, GFP_KERNEL);
1167 if (!buf)
1168 return -ENOMEM;
1169
1170 /* Do we have a bbt per chip? */
1171 if (td->options & NAND_BBT_PERCHIP) {
1172 chip = (int)(offs >> this->chip_shift);
1173 chipsel = chip;
1174 } else {
1175 chip = 0;
1176 chipsel = -1;
1177 }
1178
1179 td->version[chip]++;
1180 if (md)
1181 md->version[chip]++;
1182
1183 /* Write the bad block table to the device? */
1184 if (td->options & NAND_BBT_WRITE) {
1185 res = write_bbt(mtd, buf, td, md, chipsel);
1186 if (res < 0)
1187 goto out;
1188 }
1189 /* Write the mirror bad block table to the device? */
1190 if (md && (md->options & NAND_BBT_WRITE)) {
1191 res = write_bbt(mtd, buf, md, td, chipsel);
1192 }
1193
1194 out:
1195 kfree(buf);
1196 return res;
1197}
1198
1199/*
1200 * Define some generic bad / good block scan pattern which are used
1201 * while scanning a device for factory marked good / bad blocks.
1202 */
1203static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1204
1205/* Generic flash bbt descriptors */
1206static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1207static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1208
1209static struct nand_bbt_descr bbt_main_descr = {
1210 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1211 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1212 .offs = 8,
1213 .len = 4,
1214 .veroffs = 12,
1215 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1216 .pattern = bbt_pattern
1217};
1218
1219static struct nand_bbt_descr bbt_mirror_descr = {
1220 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1221 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1222 .offs = 8,
1223 .len = 4,
1224 .veroffs = 12,
1225 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1226 .pattern = mirror_pattern
1227};
1228
1229static struct nand_bbt_descr bbt_main_no_oob_descr = {
1230 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1231 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1232 | NAND_BBT_NO_OOB,
1233 .len = 4,
1234 .veroffs = 4,
1235 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1236 .pattern = bbt_pattern
1237};
1238
1239static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1240 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1241 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1242 | NAND_BBT_NO_OOB,
1243 .len = 4,
1244 .veroffs = 4,
1245 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1246 .pattern = mirror_pattern
1247};
1248
1249#define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1250/**
1251 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1252 * @this: NAND chip to create descriptor for
1253 *
1254 * This function allocates and initializes a nand_bbt_descr for BBM detection
1255 * based on the properties of @this. The new descriptor is stored in
1256 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1257 * passed to this function.
1258 */
1259static int nand_create_badblock_pattern(struct nand_chip *this)
1260{
1261 struct nand_bbt_descr *bd;
1262 if (this->badblock_pattern) {
1263 pr_warn("Bad block pattern already allocated; not replacing\n");
1264 return -EINVAL;
1265 }
1266 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1267 if (!bd)
1268 return -ENOMEM;
1269 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1270 bd->offs = this->badblockpos;
1271 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1272 bd->pattern = scan_ff_pattern;
1273 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1274 this->badblock_pattern = bd;
1275 return 0;
1276}
1277
1278/**
1279 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1280 * @mtd: MTD device structure
1281 *
1282 * This function selects the default bad block table support for the device and
1283 * calls the nand_scan_bbt function.
1284 */
1285int nand_default_bbt(struct mtd_info *mtd)
1286{
1287 struct nand_chip *this = mtd->priv;
1288
1289 /* Is a flash based bad block table requested? */
1290 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1291 /* Use the default pattern descriptors */
1292 if (!this->bbt_td) {
1293 if (this->bbt_options & NAND_BBT_NO_OOB) {
1294 this->bbt_td = &bbt_main_no_oob_descr;
1295 this->bbt_md = &bbt_mirror_no_oob_descr;
1296 } else {
1297 this->bbt_td = &bbt_main_descr;
1298 this->bbt_md = &bbt_mirror_descr;
1299 }
1300 }
1301 } else {
1302 this->bbt_td = NULL;
1303 this->bbt_md = NULL;
1304 }
1305
1306 if (!this->badblock_pattern)
1307 nand_create_badblock_pattern(this);
1308
1309 return nand_scan_bbt(mtd, this->badblock_pattern);
1310}
1311
1312/**
1313 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1314 * @mtd: MTD device structure
1315 * @offs: offset in the device
1316 * @allowbbt: allow access to bad block table region
1317 */
1318int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1319{
1320 struct nand_chip *this = mtd->priv;
1321 int block, res;
1322
1323 block = (int)(offs >> this->bbt_erase_shift);
1324 res = bbt_get_entry(this, block);
1325
1326 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: "
1327 "(block %d) 0x%02x\n",
1328 (unsigned int)offs, block, res);
1329
1330 switch (res) {
1331 case BBT_BLOCK_GOOD:
1332 return 0;
1333 case BBT_BLOCK_WORN:
1334 return 1;
1335 case BBT_BLOCK_RESERVED:
1336 return allowbbt ? 0 : 1;
1337 }
1338 return 1;
1339}
1340
1341/**
1342 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1343 * @mtd: MTD device structure
1344 * @offs: offset of the bad block
1345 */
1346int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs)
1347{
1348 struct nand_chip *this = mtd->priv;
1349 int block, ret = 0;
1350
1351 block = (int)(offs >> this->bbt_erase_shift);
1352
1353 /* Mark bad block in memory */
1354 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
1355
1356 /* Update flash-based bad block table */
1357 if (this->bbt_options & NAND_BBT_USE_FLASH)
1358 ret = nand_update_bbt(mtd, offs);
1359
1360 return ret;
1361}
1362
1363EXPORT_SYMBOL(nand_scan_bbt);