1 /*
2 * Overview:
3 * Bad block table support for the NAND driver
4 *
5 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * Description:
12 *
13 * When nand_scan_bbt is called, then it tries to find the bad block table
14 * depending on the options in the BBT descriptor(s). If no flash based BBT
15 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
16 * marked good / bad blocks. This information is used to create a memory BBT.
17 * Once a new bad block is discovered then the "factory" information is updated
18 * on the device.
19 * If a flash based BBT is specified then the function first tries to find the
20 * BBT on flash. If a BBT is found then the contents are read and the memory
21 * based BBT is created. If a mirrored BBT is selected then the mirror is
22 * searched too and the versions are compared. If the mirror has a greater
23 * version number, then the mirror BBT is used to build the memory based BBT.
24 * If the tables are not versioned, then we "or" the bad block information.
25 * If one of the BBTs is out of date or does not exist it is (re)created.
26 * If no BBT exists at all then the device is scanned for factory marked
27 * good / bad blocks and the bad block tables are created.
28 *
29 * For manufacturer created BBTs like the one found on M-SYS DOC devices
30 * the BBT is searched and read but never created
31 *
32 * The auto generated bad block table is located in the last good blocks
33 * of the device. The table is mirrored, so it can be updated eventually.
34 * The table is marked in the OOB area with an ident pattern and a version
35 * number which indicates which of both tables is more up to date. If the NAND
36 * controller needs the complete OOB area for the ECC information then the
37 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
38 * course): it moves the ident pattern and the version byte into the data area
39 * and the OOB area will remain untouched.
40 *
41 * The table uses 2 bits per block
42 * 11b: block is good
43 * 00b: block is factory marked bad
44 * 01b, 10b: block is marked bad due to wear
45 *
46 * The memory bad block table uses the following scheme:
47 * 00b: block is good
48 * 01b: block is marked bad due to wear
49 * 10b: block is reserved (to protect the bbt area)
50 * 11b: block is factory marked bad
51 *
52 * Multichip devices like DOC store the bad block info per floor.
53 *
54 * Following assumptions are made:
55 * - bbts start at a page boundary, if autolocated on a block boundary
56 * - the space necessary for a bbt in FLASH does not exceed a block boundary
57 *
58 */
59
60 #include <common.h>
61 #include <malloc.h>
62 #include <linux/compat.h>
63 #include <linux/mtd/mtd.h>
64 #include <linux/mtd/bbm.h>
65 #include <linux/mtd/rawnand.h>
66 #include <linux/bitops.h>
67 #include <linux/string.h>
68
69 #define BBT_BLOCK_GOOD 0x00
70 #define BBT_BLOCK_WORN 0x01
71 #define BBT_BLOCK_RESERVED 0x02
72 #define BBT_BLOCK_FACTORY_BAD 0x03
73
74 #define BBT_ENTRY_MASK 0x03
75 #define BBT_ENTRY_SHIFT 2
76
77 static int nand_update_bbt(struct mtd_info *mtd, loff_t offs);
78
bbt_get_entry(struct nand_chip * chip,int block)79 static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)
80 {
81 uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];
82 entry >>= (block & BBT_ENTRY_MASK) * 2;
83 return entry & BBT_ENTRY_MASK;
84 }
85
bbt_mark_entry(struct nand_chip * chip,int block,uint8_t mark)86 static inline void bbt_mark_entry(struct nand_chip *chip, int block,
87 uint8_t mark)
88 {
89 uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
90 chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
91 }
92
check_pattern_no_oob(uint8_t * buf,struct nand_bbt_descr * td)93 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
94 {
95 if (memcmp(buf, td->pattern, td->len))
96 return -1;
97 return 0;
98 }
99
100 /**
101 * check_pattern - [GENERIC] check if a pattern is in the buffer
102 * @buf: the buffer to search
103 * @len: the length of buffer to search
104 * @paglen: the pagelength
105 * @td: search pattern descriptor
106 *
107 * Check for a pattern at the given place. Used to search bad block tables and
108 * good / bad block identifiers.
109 */
check_pattern(uint8_t * buf,int len,int paglen,struct nand_bbt_descr * td)110 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
111 {
112 if (td->options & NAND_BBT_NO_OOB)
113 return check_pattern_no_oob(buf, td);
114
115 /* Compare the pattern */
116 if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
117 return -1;
118
119 return 0;
120 }
121
122 /**
123 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
124 * @buf: the buffer to search
125 * @td: search pattern descriptor
126 *
127 * Check for a pattern at the given place. Used to search bad block tables and
128 * good / bad block identifiers. Same as check_pattern, but no optional empty
129 * check.
130 */
check_short_pattern(uint8_t * buf,struct nand_bbt_descr * td)131 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
132 {
133 /* Compare the pattern */
134 if (memcmp(buf + td->offs, td->pattern, td->len))
135 return -1;
136 return 0;
137 }
138
139 /**
140 * add_marker_len - compute the length of the marker in data area
141 * @td: BBT descriptor used for computation
142 *
143 * The length will be 0 if the marker is located in OOB area.
144 */
add_marker_len(struct nand_bbt_descr * td)145 static u32 add_marker_len(struct nand_bbt_descr *td)
146 {
147 u32 len;
148
149 if (!(td->options & NAND_BBT_NO_OOB))
150 return 0;
151
152 len = td->len;
153 if (td->options & NAND_BBT_VERSION)
154 len++;
155 return len;
156 }
157
158 /**
159 * read_bbt - [GENERIC] Read the bad block table starting from page
160 * @mtd: MTD device structure
161 * @buf: temporary buffer
162 * @page: the starting page
163 * @num: the number of bbt descriptors to read
164 * @td: the bbt describtion table
165 * @offs: block number offset in the table
166 *
167 * Read the bad block table starting from page.
168 */
read_bbt(struct mtd_info * mtd,uint8_t * buf,int page,int num,struct nand_bbt_descr * td,int offs)169 static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
170 struct nand_bbt_descr *td, int offs)
171 {
172 int res, ret = 0, i, j, act = 0;
173 struct nand_chip *this = mtd_to_nand(mtd);
174 size_t retlen, len, totlen;
175 loff_t from;
176 int bits = td->options & NAND_BBT_NRBITS_MSK;
177 uint8_t msk = (uint8_t)((1 << bits) - 1);
178 u32 marker_len;
179 int reserved_block_code = td->reserved_block_code;
180
181 totlen = (num * bits) >> 3;
182 marker_len = add_marker_len(td);
183 from = ((loff_t)page) << this->page_shift;
184
185 while (totlen) {
186 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
187 if (marker_len) {
188 /*
189 * In case the BBT marker is not in the OOB area it
190 * will be just in the first page.
191 */
192 len -= marker_len;
193 from += marker_len;
194 marker_len = 0;
195 }
196 res = mtd_read(mtd, from, len, &retlen, buf);
197 if (res < 0) {
198 if (mtd_is_eccerr(res)) {
199 pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
200 from & ~mtd->writesize);
201 return res;
202 } else if (mtd_is_bitflip(res)) {
203 pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
204 from & ~mtd->writesize);
205 ret = res;
206 } else {
207 pr_info("nand_bbt: error reading BBT\n");
208 return res;
209 }
210 }
211
212 /* Analyse data */
213 for (i = 0; i < len; i++) {
214 uint8_t dat = buf[i];
215 for (j = 0; j < 8; j += bits, act++) {
216 uint8_t tmp = (dat >> j) & msk;
217 if (tmp == msk)
218 continue;
219 if (reserved_block_code && (tmp == reserved_block_code)) {
220 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
221 (loff_t)(offs + act) <<
222 this->bbt_erase_shift);
223 bbt_mark_entry(this, offs + act,
224 BBT_BLOCK_RESERVED);
225 mtd->ecc_stats.bbtblocks++;
226 continue;
227 }
228 /*
229 * Leave it for now, if it's matured we can
230 * move this message to pr_debug.
231 */
232 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
233 (loff_t)(offs + act) <<
234 this->bbt_erase_shift);
235 /* Factory marked bad or worn out? */
236 if (tmp == 0)
237 bbt_mark_entry(this, offs + act,
238 BBT_BLOCK_FACTORY_BAD);
239 else
240 bbt_mark_entry(this, offs + act,
241 BBT_BLOCK_WORN);
242 mtd->ecc_stats.badblocks++;
243 }
244 }
245 totlen -= len;
246 from += len;
247 }
248 return ret;
249 }
250
251 /**
252 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
253 * @mtd: MTD device structure
254 * @buf: temporary buffer
255 * @td: descriptor for the bad block table
256 * @chip: read the table for a specific chip, -1 read all chips; applies only if
257 * NAND_BBT_PERCHIP option is set
258 *
259 * Read the bad block table for all chips starting at a given page. We assume
260 * that the bbt bits are in consecutive order.
261 */
read_abs_bbt(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * td,int chip)262 static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
263 {
264 struct nand_chip *this = mtd_to_nand(mtd);
265 int res = 0, i;
266
267 if (td->options & NAND_BBT_PERCHIP) {
268 int offs = 0;
269 for (i = 0; i < this->numchips; i++) {
270 if (chip == -1 || chip == i)
271 res = read_bbt(mtd, buf, td->pages[i],
272 this->chipsize >> this->bbt_erase_shift,
273 td, offs);
274 if (res)
275 return res;
276 offs += this->chipsize >> this->bbt_erase_shift;
277 }
278 } else {
279 res = read_bbt(mtd, buf, td->pages[0],
280 mtd->size >> this->bbt_erase_shift, td, 0);
281 if (res)
282 return res;
283 }
284 return 0;
285 }
286
287 /* BBT marker is in the first page, no OOB */
scan_read_data(struct mtd_info * mtd,uint8_t * buf,loff_t offs,struct nand_bbt_descr * td)288 static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
289 struct nand_bbt_descr *td)
290 {
291 size_t retlen;
292 size_t len;
293
294 len = td->len;
295 if (td->options & NAND_BBT_VERSION)
296 len++;
297
298 return mtd_read(mtd, offs, len, &retlen, buf);
299 }
300
301 /**
302 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
303 * @mtd: MTD device structure
304 * @buf: temporary buffer
305 * @offs: offset at which to scan
306 * @len: length of data region to read
307 *
308 * Scan read data from data+OOB. May traverse multiple pages, interleaving
309 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
310 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
311 */
scan_read_oob(struct mtd_info * mtd,uint8_t * buf,loff_t offs,size_t len)312 static int scan_read_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
313 size_t len)
314 {
315 struct mtd_oob_ops ops;
316 int res, ret = 0;
317
318 ops.mode = MTD_OPS_PLACE_OOB;
319 ops.ooboffs = 0;
320 ops.ooblen = mtd->oobsize;
321
322 while (len > 0) {
323 ops.datbuf = buf;
324 ops.len = min(len, (size_t)mtd->writesize);
325 ops.oobbuf = buf + ops.len;
326
327 res = mtd_read_oob(mtd, offs, &ops);
328 if (res) {
329 if (!mtd_is_bitflip_or_eccerr(res))
330 return res;
331 else if (mtd_is_eccerr(res) || !ret)
332 ret = res;
333 }
334
335 buf += mtd->oobsize + mtd->writesize;
336 len -= mtd->writesize;
337 offs += mtd->writesize;
338 }
339 return ret;
340 }
341
scan_read(struct mtd_info * mtd,uint8_t * buf,loff_t offs,size_t len,struct nand_bbt_descr * td)342 static int scan_read(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
343 size_t len, struct nand_bbt_descr *td)
344 {
345 if (td->options & NAND_BBT_NO_OOB)
346 return scan_read_data(mtd, buf, offs, td);
347 else
348 return scan_read_oob(mtd, buf, offs, len);
349 }
350
351 /* Scan write data with oob to flash */
scan_write_bbt(struct mtd_info * mtd,loff_t offs,size_t len,uint8_t * buf,uint8_t * oob)352 static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
353 uint8_t *buf, uint8_t *oob)
354 {
355 struct mtd_oob_ops ops;
356
357 ops.mode = MTD_OPS_PLACE_OOB;
358 ops.ooboffs = 0;
359 ops.ooblen = mtd->oobsize;
360 ops.datbuf = buf;
361 ops.oobbuf = oob;
362 ops.len = len;
363
364 return mtd_write_oob(mtd, offs, &ops);
365 }
366
bbt_get_ver_offs(struct mtd_info * mtd,struct nand_bbt_descr * td)367 static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
368 {
369 u32 ver_offs = td->veroffs;
370
371 if (!(td->options & NAND_BBT_NO_OOB))
372 ver_offs += mtd->writesize;
373 return ver_offs;
374 }
375
376 /**
377 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
378 * @mtd: MTD device structure
379 * @buf: temporary buffer
380 * @td: descriptor for the bad block table
381 * @md: descriptor for the bad block table mirror
382 *
383 * Read the bad block table(s) for all chips starting at a given page. We
384 * assume that the bbt bits are in consecutive order.
385 */
read_abs_bbts(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * td,struct nand_bbt_descr * md)386 static void read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
387 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
388 {
389 struct nand_chip *this = mtd_to_nand(mtd);
390
391 /* Read the primary version, if available */
392 if (td->options & NAND_BBT_VERSION) {
393 scan_read(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
394 mtd->writesize, td);
395 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
396 pr_info("Bad block table at page %d, version 0x%02X\n",
397 td->pages[0], td->version[0]);
398 }
399
400 /* Read the mirror version, if available */
401 if (md && (md->options & NAND_BBT_VERSION)) {
402 scan_read(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
403 mtd->writesize, md);
404 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
405 pr_info("Bad block table at page %d, version 0x%02X\n",
406 md->pages[0], md->version[0]);
407 }
408 }
409
410 /* Scan a given block partially */
scan_block_fast(struct mtd_info * mtd,struct nand_bbt_descr * bd,loff_t offs,uint8_t * buf,int numpages)411 static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
412 loff_t offs, uint8_t *buf, int numpages)
413 {
414 struct mtd_oob_ops ops;
415 int j, ret;
416
417 ops.ooblen = mtd->oobsize;
418 ops.oobbuf = buf;
419 ops.ooboffs = 0;
420 ops.datbuf = NULL;
421 ops.mode = MTD_OPS_PLACE_OOB;
422
423 for (j = 0; j < numpages; j++) {
424 /*
425 * Read the full oob until read_oob is fixed to handle single
426 * byte reads for 16 bit buswidth.
427 */
428 ret = mtd_read_oob(mtd, offs, &ops);
429 /* Ignore ECC errors when checking for BBM */
430 if (ret && !mtd_is_bitflip_or_eccerr(ret))
431 return ret;
432
433 if (check_short_pattern(buf, bd))
434 return 1;
435
436 offs += mtd->writesize;
437 }
438 return 0;
439 }
440
441 /**
442 * create_bbt - [GENERIC] Create a bad block table by scanning the device
443 * @mtd: MTD device structure
444 * @buf: temporary buffer
445 * @bd: descriptor for the good/bad block search pattern
446 * @chip: create the table for a specific chip, -1 read all chips; applies only
447 * if NAND_BBT_PERCHIP option is set
448 *
449 * Create a bad block table by scanning the device for the given good/bad block
450 * identify pattern.
451 */
create_bbt(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * bd,int chip)452 static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
453 struct nand_bbt_descr *bd, int chip)
454 {
455 struct nand_chip *this = mtd_to_nand(mtd);
456 int i, numblocks, numpages;
457 int startblock;
458 loff_t from;
459
460 pr_info("Scanning device for bad blocks\n");
461
462 if (bd->options & NAND_BBT_SCAN2NDPAGE)
463 numpages = 2;
464 else
465 numpages = 1;
466
467 if (chip == -1) {
468 numblocks = mtd->size >> this->bbt_erase_shift;
469 startblock = 0;
470 from = 0;
471 } else {
472 if (chip >= this->numchips) {
473 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
474 chip + 1, this->numchips);
475 return -EINVAL;
476 }
477 numblocks = this->chipsize >> this->bbt_erase_shift;
478 startblock = chip * numblocks;
479 numblocks += startblock;
480 from = (loff_t)startblock << this->bbt_erase_shift;
481 }
482
483 if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
484 from += mtd->erasesize - (mtd->writesize * numpages);
485
486 for (i = startblock; i < numblocks; i++) {
487 int ret;
488
489 BUG_ON(bd->options & NAND_BBT_NO_OOB);
490
491 ret = scan_block_fast(mtd, bd, from, buf, numpages);
492 if (ret < 0)
493 return ret;
494
495 if (ret) {
496 bbt_mark_entry(this, i, BBT_BLOCK_FACTORY_BAD);
497 pr_warn("Bad eraseblock %d at 0x%012llx\n",
498 i, (unsigned long long)from);
499 mtd->ecc_stats.badblocks++;
500 }
501
502 from += (1 << this->bbt_erase_shift);
503 }
504 return 0;
505 }
506
507 /**
508 * search_bbt - [GENERIC] scan the device for a specific bad block table
509 * @mtd: MTD device structure
510 * @buf: temporary buffer
511 * @td: descriptor for the bad block table
512 *
513 * Read the bad block table by searching for a given ident pattern. Search is
514 * preformed either from the beginning up or from the end of the device
515 * downwards. The search starts always at the start of a block. If the option
516 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
517 * the bad block information of this chip. This is necessary to provide support
518 * for certain DOC devices.
519 *
520 * The bbt ident pattern resides in the oob area of the first page in a block.
521 */
search_bbt(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * td)522 static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
523 {
524 struct nand_chip *this = mtd_to_nand(mtd);
525 int i, chips;
526 int startblock, block, dir;
527 int scanlen = mtd->writesize + mtd->oobsize;
528 int bbtblocks;
529 int blocktopage = this->bbt_erase_shift - this->page_shift;
530
531 /* Search direction top -> down? */
532 if (td->options & NAND_BBT_LASTBLOCK) {
533 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
534 dir = -1;
535 } else {
536 startblock = 0;
537 dir = 1;
538 }
539
540 /* Do we have a bbt per chip? */
541 if (td->options & NAND_BBT_PERCHIP) {
542 chips = this->numchips;
543 bbtblocks = this->chipsize >> this->bbt_erase_shift;
544 startblock &= bbtblocks - 1;
545 } else {
546 chips = 1;
547 bbtblocks = mtd->size >> this->bbt_erase_shift;
548 }
549
550 for (i = 0; i < chips; i++) {
551 /* Reset version information */
552 td->version[i] = 0;
553 td->pages[i] = -1;
554 /* Scan the maximum number of blocks */
555 for (block = 0; block < td->maxblocks; block++) {
556
557 int actblock = startblock + dir * block;
558 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
559
560 /* Read first page */
561 scan_read(mtd, buf, offs, mtd->writesize, td);
562 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
563 td->pages[i] = actblock << blocktopage;
564 if (td->options & NAND_BBT_VERSION) {
565 offs = bbt_get_ver_offs(mtd, td);
566 td->version[i] = buf[offs];
567 }
568 break;
569 }
570 }
571 startblock += this->chipsize >> this->bbt_erase_shift;
572 }
573 /* Check, if we found a bbt for each requested chip */
574 for (i = 0; i < chips; i++) {
575 if (td->pages[i] == -1)
576 pr_warn("Bad block table not found for chip %d\n", i);
577 else
578 pr_info("Bad block table found at page %d, version 0x%02X\n",
579 td->pages[i], td->version[i]);
580 }
581 return 0;
582 }
583
584 /**
585 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
586 * @mtd: MTD device structure
587 * @buf: temporary buffer
588 * @td: descriptor for the bad block table
589 * @md: descriptor for the bad block table mirror
590 *
591 * Search and read the bad block table(s).
592 */
search_read_bbts(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * td,struct nand_bbt_descr * md)593 static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf,
594 struct nand_bbt_descr *td,
595 struct nand_bbt_descr *md)
596 {
597 /* Search the primary table */
598 search_bbt(mtd, buf, td);
599
600 /* Search the mirror table */
601 if (md)
602 search_bbt(mtd, buf, md);
603 }
604
605 /**
606 * write_bbt - [GENERIC] (Re)write the bad block table
607 * @mtd: MTD device structure
608 * @buf: temporary buffer
609 * @td: descriptor for the bad block table
610 * @md: descriptor for the bad block table mirror
611 * @chipsel: selector for a specific chip, -1 for all
612 *
613 * (Re)write the bad block table.
614 */
write_bbt(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * td,struct nand_bbt_descr * md,int chipsel)615 static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
616 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
617 int chipsel)
618 {
619 struct nand_chip *this = mtd_to_nand(mtd);
620 struct erase_info einfo;
621 int i, res, chip = 0;
622 int bits, startblock, dir, page, offs, numblocks, sft, sftmsk;
623 int nrchips, pageoffs, ooboffs;
624 uint8_t msk[4];
625 uint8_t rcode = td->reserved_block_code;
626 size_t retlen, len = 0;
627 loff_t to;
628 struct mtd_oob_ops ops;
629
630 ops.ooblen = mtd->oobsize;
631 ops.ooboffs = 0;
632 ops.datbuf = NULL;
633 ops.mode = MTD_OPS_PLACE_OOB;
634
635 if (!rcode)
636 rcode = 0xff;
637 /* Write bad block table per chip rather than per device? */
638 if (td->options & NAND_BBT_PERCHIP) {
639 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
640 /* Full device write or specific chip? */
641 if (chipsel == -1) {
642 nrchips = this->numchips;
643 } else {
644 nrchips = chipsel + 1;
645 chip = chipsel;
646 }
647 } else {
648 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
649 nrchips = 1;
650 }
651
652 /* Loop through the chips */
653 for (; chip < nrchips; chip++) {
654 /*
655 * There was already a version of the table, reuse the page
656 * This applies for absolute placement too, as we have the
657 * page nr. in td->pages.
658 */
659 if (td->pages[chip] != -1) {
660 page = td->pages[chip];
661 goto write;
662 }
663
664 /*
665 * Automatic placement of the bad block table. Search direction
666 * top -> down?
667 */
668 if (td->options & NAND_BBT_LASTBLOCK) {
669 startblock = numblocks * (chip + 1) - 1;
670 dir = -1;
671 } else {
672 startblock = chip * numblocks;
673 dir = 1;
674 }
675
676 for (i = 0; i < td->maxblocks; i++) {
677 int block = startblock + dir * i;
678 /* Check, if the block is bad */
679 switch (bbt_get_entry(this, block)) {
680 case BBT_BLOCK_WORN:
681 case BBT_BLOCK_FACTORY_BAD:
682 continue;
683 }
684 page = block <<
685 (this->bbt_erase_shift - this->page_shift);
686 /* Check, if the block is used by the mirror table */
687 if (!md || md->pages[chip] != page)
688 goto write;
689 }
690 pr_err("No space left to write bad block table\n");
691 return -ENOSPC;
692 write:
693
694 /* Set up shift count and masks for the flash table */
695 bits = td->options & NAND_BBT_NRBITS_MSK;
696 msk[2] = ~rcode;
697 switch (bits) {
698 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
699 msk[3] = 0x01;
700 break;
701 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
702 msk[3] = 0x03;
703 break;
704 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
705 msk[3] = 0x0f;
706 break;
707 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
708 msk[3] = 0xff;
709 break;
710 default: return -EINVAL;
711 }
712
713 to = ((loff_t)page) << this->page_shift;
714
715 /* Must we save the block contents? */
716 if (td->options & NAND_BBT_SAVECONTENT) {
717 /* Make it block aligned */
718 to &= ~(((loff_t)1 << this->bbt_erase_shift) - 1);
719 len = 1 << this->bbt_erase_shift;
720 res = mtd_read(mtd, to, len, &retlen, buf);
721 if (res < 0) {
722 if (retlen != len) {
723 pr_info("nand_bbt: error reading block for writing the bad block table\n");
724 return res;
725 }
726 pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
727 }
728 /* Read oob data */
729 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
730 ops.oobbuf = &buf[len];
731 res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
732 if (res < 0 || ops.oobretlen != ops.ooblen)
733 goto outerr;
734
735 /* Calc the byte offset in the buffer */
736 pageoffs = page - (int)(to >> this->page_shift);
737 offs = pageoffs << this->page_shift;
738 /* Preset the bbt area with 0xff */
739 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
740 ooboffs = len + (pageoffs * mtd->oobsize);
741
742 } else if (td->options & NAND_BBT_NO_OOB) {
743 ooboffs = 0;
744 offs = td->len;
745 /* The version byte */
746 if (td->options & NAND_BBT_VERSION)
747 offs++;
748 /* Calc length */
749 len = (size_t)(numblocks >> sft);
750 len += offs;
751 /* Make it page aligned! */
752 len = ALIGN(len, mtd->writesize);
753 /* Preset the buffer with 0xff */
754 memset(buf, 0xff, len);
755 /* Pattern is located at the begin of first page */
756 memcpy(buf, td->pattern, td->len);
757 } else {
758 /* Calc length */
759 len = (size_t)(numblocks >> sft);
760 /* Make it page aligned! */
761 len = ALIGN(len, mtd->writesize);
762 /* Preset the buffer with 0xff */
763 memset(buf, 0xff, len +
764 (len >> this->page_shift)* mtd->oobsize);
765 offs = 0;
766 ooboffs = len;
767 /* Pattern is located in oob area of first page */
768 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
769 }
770
771 if (td->options & NAND_BBT_VERSION)
772 buf[ooboffs + td->veroffs] = td->version[chip];
773
774 /* Walk through the memory table */
775 for (i = 0; i < numblocks; i++) {
776 uint8_t dat;
777 int sftcnt = (i << (3 - sft)) & sftmsk;
778 dat = bbt_get_entry(this, chip * numblocks + i);
779 /* Do not store the reserved bbt blocks! */
780 buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
781 }
782
783 memset(&einfo, 0, sizeof(einfo));
784 einfo.mtd = mtd;
785 einfo.addr = to;
786 einfo.len = 1 << this->bbt_erase_shift;
787 res = nand_erase_nand(mtd, &einfo, 1);
788 if (res < 0)
789 goto outerr;
790
791 res = scan_write_bbt(mtd, to, len, buf,
792 td->options & NAND_BBT_NO_OOB ? NULL :
793 &buf[len]);
794 if (res < 0)
795 goto outerr;
796
797 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
798 (unsigned long long)to, td->version[chip]);
799
800 /* Mark it as used */
801 td->pages[chip] = page;
802 }
803 return 0;
804
805 outerr:
806 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
807 return res;
808 }
809
810 /**
811 * nand_memory_bbt - [GENERIC] create a memory based bad block table
812 * @mtd: MTD device structure
813 * @bd: descriptor for the good/bad block search pattern
814 *
815 * The function creates a memory based bbt by scanning the device for
816 * manufacturer / software marked good / bad blocks.
817 */
nand_memory_bbt(struct mtd_info * mtd,struct nand_bbt_descr * bd)818 static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
819 {
820 struct nand_chip *this = mtd_to_nand(mtd);
821
822 return create_bbt(mtd, this->buffers->databuf, bd, -1);
823 }
824
825 /**
826 * check_create - [GENERIC] create and write bbt(s) if necessary
827 * @mtd: MTD device structure
828 * @buf: temporary buffer
829 * @bd: descriptor for the good/bad block search pattern
830 *
831 * The function checks the results of the previous call to read_bbt and creates
832 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
833 * for the chip/device. Update is necessary if one of the tables is missing or
834 * the version nr. of one table is less than the other.
835 */
check_create(struct mtd_info * mtd,uint8_t * buf,struct nand_bbt_descr * bd)836 static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
837 {
838 int i, chips, writeops, create, chipsel, res, res2;
839 struct nand_chip *this = mtd_to_nand(mtd);
840 struct nand_bbt_descr *td = this->bbt_td;
841 struct nand_bbt_descr *md = this->bbt_md;
842 struct nand_bbt_descr *rd, *rd2;
843
844 /* Do we have a bbt per chip? */
845 if (td->options & NAND_BBT_PERCHIP)
846 chips = this->numchips;
847 else
848 chips = 1;
849
850 for (i = 0; i < chips; i++) {
851 writeops = 0;
852 create = 0;
853 rd = NULL;
854 rd2 = NULL;
855 res = res2 = 0;
856 /* Per chip or per device? */
857 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
858 /* Mirrored table available? */
859 if (md) {
860 if (td->pages[i] == -1 && md->pages[i] == -1) {
861 create = 1;
862 writeops = 0x03;
863 } else if (td->pages[i] == -1) {
864 rd = md;
865 writeops = 0x01;
866 } else if (md->pages[i] == -1) {
867 rd = td;
868 writeops = 0x02;
869 } else if (td->version[i] == md->version[i]) {
870 rd = td;
871 if (!(td->options & NAND_BBT_VERSION))
872 rd2 = md;
873 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
874 rd = td;
875 writeops = 0x02;
876 } else {
877 rd = md;
878 writeops = 0x01;
879 }
880 } else {
881 if (td->pages[i] == -1) {
882 create = 1;
883 writeops = 0x01;
884 } else {
885 rd = td;
886 }
887 }
888
889 if (create) {
890 /* Create the bad block table by scanning the device? */
891 if (!(td->options & NAND_BBT_CREATE))
892 continue;
893
894 /* Create the table in memory by scanning the chip(s) */
895 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
896 create_bbt(mtd, buf, bd, chipsel);
897
898 td->version[i] = 1;
899 if (md)
900 md->version[i] = 1;
901 }
902
903 /* Read back first? */
904 if (rd) {
905 res = read_abs_bbt(mtd, buf, rd, chipsel);
906 if (mtd_is_eccerr(res)) {
907 /* Mark table as invalid */
908 rd->pages[i] = -1;
909 rd->version[i] = 0;
910 i--;
911 continue;
912 }
913 }
914 /* If they weren't versioned, read both */
915 if (rd2) {
916 res2 = read_abs_bbt(mtd, buf, rd2, chipsel);
917 if (mtd_is_eccerr(res2)) {
918 /* Mark table as invalid */
919 rd2->pages[i] = -1;
920 rd2->version[i] = 0;
921 i--;
922 continue;
923 }
924 }
925
926 /* Scrub the flash table(s)? */
927 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
928 writeops = 0x03;
929
930 /* Update version numbers before writing */
931 if (md) {
932 td->version[i] = max(td->version[i], md->version[i]);
933 md->version[i] = td->version[i];
934 }
935
936 /* Write the bad block table to the device? */
937 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
938 res = write_bbt(mtd, buf, td, md, chipsel);
939 if (res < 0)
940 return res;
941 }
942
943 /* Write the mirror bad block table to the device? */
944 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
945 res = write_bbt(mtd, buf, md, td, chipsel);
946 if (res < 0)
947 return res;
948 }
949 }
950 return 0;
951 }
952
953 /**
954 * mark_bbt_regions - [GENERIC] mark the bad block table regions
955 * @mtd: MTD device structure
956 * @td: bad block table descriptor
957 *
958 * The bad block table regions are marked as "bad" to prevent accidental
959 * erasures / writes. The regions are identified by the mark 0x02.
960 */
mark_bbt_region(struct mtd_info * mtd,struct nand_bbt_descr * td)961 static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
962 {
963 struct nand_chip *this = mtd_to_nand(mtd);
964 int i, j, chips, block, nrblocks, update;
965 uint8_t oldval;
966
967 /* Do we have a bbt per chip? */
968 if (td->options & NAND_BBT_PERCHIP) {
969 chips = this->numchips;
970 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
971 } else {
972 chips = 1;
973 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
974 }
975
976 for (i = 0; i < chips; i++) {
977 if ((td->options & NAND_BBT_ABSPAGE) ||
978 !(td->options & NAND_BBT_WRITE)) {
979 if (td->pages[i] == -1)
980 continue;
981 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
982 oldval = bbt_get_entry(this, block);
983 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
984 if ((oldval != BBT_BLOCK_RESERVED) &&
985 td->reserved_block_code)
986 nand_update_bbt(mtd, (loff_t)block <<
987 this->bbt_erase_shift);
988 continue;
989 }
990 update = 0;
991 if (td->options & NAND_BBT_LASTBLOCK)
992 block = ((i + 1) * nrblocks) - td->maxblocks;
993 else
994 block = i * nrblocks;
995 for (j = 0; j < td->maxblocks; j++) {
996 oldval = bbt_get_entry(this, block);
997 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
998 if (oldval != BBT_BLOCK_RESERVED)
999 update = 1;
1000 block++;
1001 }
1002 /*
1003 * If we want reserved blocks to be recorded to flash, and some
1004 * new ones have been marked, then we need to update the stored
1005 * bbts. This should only happen once.
1006 */
1007 if (update && td->reserved_block_code)
1008 nand_update_bbt(mtd, (loff_t)(block - 1) <<
1009 this->bbt_erase_shift);
1010 }
1011 }
1012
1013 /**
1014 * verify_bbt_descr - verify the bad block description
1015 * @mtd: MTD device structure
1016 * @bd: the table to verify
1017 *
1018 * This functions performs a few sanity checks on the bad block description
1019 * table.
1020 */
verify_bbt_descr(struct mtd_info * mtd,struct nand_bbt_descr * bd)1021 static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1022 {
1023 struct nand_chip *this = mtd_to_nand(mtd);
1024 u32 pattern_len;
1025 u32 bits;
1026 u32 table_size;
1027
1028 if (!bd)
1029 return;
1030
1031 pattern_len = bd->len;
1032 bits = bd->options & NAND_BBT_NRBITS_MSK;
1033
1034 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1035 !(this->bbt_options & NAND_BBT_USE_FLASH));
1036 BUG_ON(!bits);
1037
1038 if (bd->options & NAND_BBT_VERSION)
1039 pattern_len++;
1040
1041 if (bd->options & NAND_BBT_NO_OOB) {
1042 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1043 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1044 BUG_ON(bd->offs);
1045 if (bd->options & NAND_BBT_VERSION)
1046 BUG_ON(bd->veroffs != bd->len);
1047 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1048 }
1049
1050 if (bd->options & NAND_BBT_PERCHIP)
1051 table_size = this->chipsize >> this->bbt_erase_shift;
1052 else
1053 table_size = mtd->size >> this->bbt_erase_shift;
1054 table_size >>= 3;
1055 table_size *= bits;
1056 if (bd->options & NAND_BBT_NO_OOB)
1057 table_size += pattern_len;
1058 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1059 }
1060
1061 /**
1062 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1063 * @mtd: MTD device structure
1064 * @bd: descriptor for the good/bad block search pattern
1065 *
1066 * The function checks, if a bad block table(s) is/are already available. If
1067 * not it scans the device for manufacturer marked good / bad blocks and writes
1068 * the bad block table(s) to the selected place.
1069 *
1070 * The bad block table memory is allocated here. It must be freed by calling
1071 * the nand_free_bbt function.
1072 */
nand_scan_bbt(struct mtd_info * mtd,struct nand_bbt_descr * bd)1073 static int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1074 {
1075 struct nand_chip *this = mtd_to_nand(mtd);
1076 int len, res;
1077 uint8_t *buf;
1078 struct nand_bbt_descr *td = this->bbt_td;
1079 struct nand_bbt_descr *md = this->bbt_md;
1080
1081 len = (mtd->size >> (this->bbt_erase_shift + 2)) ? : 1;
1082 /*
1083 * Allocate memory (2bit per block) and clear the memory bad block
1084 * table.
1085 */
1086 this->bbt = kzalloc(len, GFP_KERNEL);
1087 if (!this->bbt)
1088 return -ENOMEM;
1089
1090 /*
1091 * If no primary table decriptor is given, scan the device to build a
1092 * memory based bad block table.
1093 */
1094 if (!td) {
1095 if ((res = nand_memory_bbt(mtd, bd))) {
1096 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1097 goto err;
1098 }
1099 return 0;
1100 }
1101 verify_bbt_descr(mtd, td);
1102 verify_bbt_descr(mtd, md);
1103
1104 /* Allocate a temporary buffer for one eraseblock incl. oob */
1105 len = (1 << this->bbt_erase_shift);
1106 len += (len >> this->page_shift) * mtd->oobsize;
1107 buf = vmalloc(len);
1108 if (!buf) {
1109 res = -ENOMEM;
1110 goto err;
1111 }
1112
1113 /* Is the bbt at a given page? */
1114 if (td->options & NAND_BBT_ABSPAGE) {
1115 read_abs_bbts(mtd, buf, td, md);
1116 } else {
1117 /* Search the bad block table using a pattern in oob */
1118 search_read_bbts(mtd, buf, td, md);
1119 }
1120
1121 res = check_create(mtd, buf, bd);
1122 if (res)
1123 goto err;
1124
1125 /* Prevent the bbt regions from erasing / writing */
1126 mark_bbt_region(mtd, td);
1127 if (md)
1128 mark_bbt_region(mtd, md);
1129
1130 vfree(buf);
1131 return 0;
1132
1133 err:
1134 kfree(this->bbt);
1135 this->bbt = NULL;
1136 return res;
1137 }
1138
1139 /**
1140 * nand_update_bbt - update bad block table(s)
1141 * @mtd: MTD device structure
1142 * @offs: the offset of the newly marked block
1143 *
1144 * The function updates the bad block table(s).
1145 */
nand_update_bbt(struct mtd_info * mtd,loff_t offs)1146 static int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1147 {
1148 struct nand_chip *this = mtd_to_nand(mtd);
1149 int len, res = 0;
1150 int chip, chipsel;
1151 uint8_t *buf;
1152 struct nand_bbt_descr *td = this->bbt_td;
1153 struct nand_bbt_descr *md = this->bbt_md;
1154
1155 if (!this->bbt || !td)
1156 return -EINVAL;
1157
1158 /* Allocate a temporary buffer for one eraseblock incl. oob */
1159 len = (1 << this->bbt_erase_shift);
1160 len += (len >> this->page_shift) * mtd->oobsize;
1161 buf = kmalloc(len, GFP_KERNEL);
1162 if (!buf)
1163 return -ENOMEM;
1164
1165 /* Do we have a bbt per chip? */
1166 if (td->options & NAND_BBT_PERCHIP) {
1167 chip = (int)(offs >> this->chip_shift);
1168 chipsel = chip;
1169 } else {
1170 chip = 0;
1171 chipsel = -1;
1172 }
1173
1174 td->version[chip]++;
1175 if (md)
1176 md->version[chip]++;
1177
1178 /* Write the bad block table to the device? */
1179 if (td->options & NAND_BBT_WRITE) {
1180 res = write_bbt(mtd, buf, td, md, chipsel);
1181 if (res < 0)
1182 goto out;
1183 }
1184 /* Write the mirror bad block table to the device? */
1185 if (md && (md->options & NAND_BBT_WRITE)) {
1186 res = write_bbt(mtd, buf, md, td, chipsel);
1187 }
1188
1189 out:
1190 kfree(buf);
1191 return res;
1192 }
1193
1194 /*
1195 * Define some generic bad / good block scan pattern which are used
1196 * while scanning a device for factory marked good / bad blocks.
1197 */
1198 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1199
1200 /* Generic flash bbt descriptors */
1201 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1202 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1203
1204 static struct nand_bbt_descr bbt_main_descr = {
1205 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1206 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1207 .offs = 8,
1208 .len = 4,
1209 .veroffs = 12,
1210 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1211 .pattern = bbt_pattern
1212 };
1213
1214 static struct nand_bbt_descr bbt_mirror_descr = {
1215 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1216 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1217 .offs = 8,
1218 .len = 4,
1219 .veroffs = 12,
1220 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1221 .pattern = mirror_pattern
1222 };
1223
1224 static struct nand_bbt_descr bbt_main_no_oob_descr = {
1225 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1226 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1227 | NAND_BBT_NO_OOB,
1228 .len = 4,
1229 .veroffs = 4,
1230 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1231 .pattern = bbt_pattern
1232 };
1233
1234 static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1235 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1236 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1237 | NAND_BBT_NO_OOB,
1238 .len = 4,
1239 .veroffs = 4,
1240 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1241 .pattern = mirror_pattern
1242 };
1243
1244 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1245 /**
1246 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1247 * @this: NAND chip to create descriptor for
1248 *
1249 * This function allocates and initializes a nand_bbt_descr for BBM detection
1250 * based on the properties of @this. The new descriptor is stored in
1251 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1252 * passed to this function.
1253 */
nand_create_badblock_pattern(struct nand_chip * this)1254 static int nand_create_badblock_pattern(struct nand_chip *this)
1255 {
1256 struct nand_bbt_descr *bd;
1257 if (this->badblock_pattern) {
1258 pr_warn("Bad block pattern already allocated; not replacing\n");
1259 return -EINVAL;
1260 }
1261 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1262 if (!bd)
1263 return -ENOMEM;
1264 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1265 bd->offs = this->badblockpos;
1266 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1267 bd->pattern = scan_ff_pattern;
1268 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1269 this->badblock_pattern = bd;
1270 return 0;
1271 }
1272
1273 /**
1274 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1275 * @mtd: MTD device structure
1276 *
1277 * This function selects the default bad block table support for the device and
1278 * calls the nand_scan_bbt function.
1279 */
nand_default_bbt(struct mtd_info * mtd)1280 int nand_default_bbt(struct mtd_info *mtd)
1281 {
1282 struct nand_chip *this = mtd_to_nand(mtd);
1283 int ret;
1284
1285 /* Is a flash based bad block table requested? */
1286 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1287 /* Use the default pattern descriptors */
1288 if (!this->bbt_td) {
1289 if (this->bbt_options & NAND_BBT_NO_OOB) {
1290 this->bbt_td = &bbt_main_no_oob_descr;
1291 this->bbt_md = &bbt_mirror_no_oob_descr;
1292 } else {
1293 this->bbt_td = &bbt_main_descr;
1294 this->bbt_md = &bbt_mirror_descr;
1295 }
1296 }
1297 } else {
1298 this->bbt_td = NULL;
1299 this->bbt_md = NULL;
1300 }
1301
1302 if (!this->badblock_pattern) {
1303 ret = nand_create_badblock_pattern(this);
1304 if (ret)
1305 return ret;
1306 }
1307
1308 return nand_scan_bbt(mtd, this->badblock_pattern);
1309 }
1310
1311 /**
1312 * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
1313 * @mtd: MTD device structure
1314 * @offs: offset in the device
1315 */
nand_isreserved_bbt(struct mtd_info * mtd,loff_t offs)1316 int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs)
1317 {
1318 struct nand_chip *this = mtd_to_nand(mtd);
1319 int block;
1320
1321 block = (int)(offs >> this->bbt_erase_shift);
1322 return bbt_get_entry(this, block) == BBT_BLOCK_RESERVED;
1323 }
1324
1325 /**
1326 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1327 * @mtd: MTD device structure
1328 * @offs: offset in the device
1329 * @allowbbt: allow access to bad block table region
1330 */
nand_isbad_bbt(struct mtd_info * mtd,loff_t offs,int allowbbt)1331 int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1332 {
1333 struct nand_chip *this = mtd_to_nand(mtd);
1334 int block, res;
1335
1336 block = (int)(offs >> this->bbt_erase_shift);
1337 res = bbt_get_entry(this, block);
1338
1339 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1340 (unsigned int)offs, block, res);
1341
1342 switch (res) {
1343 case BBT_BLOCK_GOOD:
1344 return 0;
1345 case BBT_BLOCK_WORN:
1346 return 1;
1347 case BBT_BLOCK_RESERVED:
1348 return allowbbt ? 0 : 1;
1349 }
1350 return 1;
1351 }
1352
1353 /**
1354 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1355 * @mtd: MTD device structure
1356 * @offs: offset of the bad block
1357 */
nand_markbad_bbt(struct mtd_info * mtd,loff_t offs)1358 int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs)
1359 {
1360 struct nand_chip *this = mtd_to_nand(mtd);
1361 int block, ret = 0;
1362
1363 block = (int)(offs >> this->bbt_erase_shift);
1364
1365 /* Mark bad block in memory */
1366 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
1367
1368 /* Update flash-based bad block table */
1369 if (this->bbt_options & NAND_BBT_USE_FLASH)
1370 ret = nand_update_bbt(mtd, offs);
1371
1372 return ret;
1373 }
1374