· 7 years ago · Feb 26, 2019, 12:22 PM
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25 * If one of the BBTs is out of date or does not exist it is (re)created.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 <linux/slab.h>
61#include <linux/types.h>
62#include <linux/mtd/mtd.h>
63#include <linux/mtd/bbm.h>
64#include <linux/mtd/rawnand.h>
65#include <linux/bitops.h>
66#include <linux/delay.h>
67#include <linux/vmalloc.h>
68#include <linux/export.h>
69#include <linux/string.h>
70
71#define BBT_BLOCK_GOOD 0x00
72#define BBT_BLOCK_WORN 0x01
73#define BBT_BLOCK_RESERVED 0x02
74#define BBT_BLOCK_FACTORY_BAD 0x03
75
76#define BBT_ENTRY_MASK 0x03
77#define BBT_ENTRY_SHIFT 2
78
79#define CUSTOMIZED_BBT 1
80#if CUSTOMIZED_BBT
81 #define BAD_BLK_OOB_MARK_START 4
82 #define BAD_BLK_OOB_MARK_END 5
83 #define BAD_BLK_OOB_MARK_PATT 0xFF
84
85
86#include <linux/mtd/rawnand.h>
87#include <linux/of.h>
88
89static bool of_get_customized_bbt_from_mtd(struct mtd_info *mtd)
90{
91 struct nand_chip *chip = mtd_to_nand(mtd);
92 struct device_node *dn = nand_get_flash_node(chip);
93 return of_property_read_bool(dn, "customized-samsung-K9F4G08U0x");
94}
95
96static bool of_get_customized_bbt_from_chip(struct nand_chip *chip)
97{
98 struct device_node *dn = nand_get_flash_node(chip);
99 return of_property_read_bool(dn, "customized-samsung-K9F4G08U0x");
100}
101
102#endif
103
104
105static int nand_update_bbt(struct mtd_info *mtd, loff_t offs);
106
107static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)
108{
109 uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];
110 entry >>= (block & BBT_ENTRY_MASK) * 2;
111 return entry & BBT_ENTRY_MASK;
112}
113
114static inline void bbt_mark_entry(struct nand_chip *chip, int block,
115 uint8_t mark)
116{
117 uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
118 chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
119}
120
121static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
122{
123 if (memcmp(buf, td->pattern, td->len))
124 return -1;
125 return 0;
126}
127
128/**
129 * check_pattern - [GENERIC] check if a pattern is in the buffer
130 * @buf: the buffer to search
131 * @len: the length of buffer to search
132 * @paglen: the pagelength
133 * @td: search pattern descriptor
134 *
135 * Check for a pattern at the given place. Used to search bad block tables and
136 * good / bad block identifiers.
137 */
138#if CUSTOMIZED_BBT
139static int check_pattern(struct mtd_info *mtd, uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
140{
141 int i;
142 uint8_t *p = buf;
143#else
144static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
145{
146#endif
147 if (td->options & NAND_BBT_NO_OOB)
148 return check_pattern_no_oob(buf, td);
149
150 /* Compare the pattern */
151 if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
152 return -1;
153
154#if CUSTOMIZED_BBT /*ctc*/
155 if (of_get_customized_bbt_from_mtd(mtd)) {
156 for (i = BAD_BLK_OOB_MARK_START, p=buf+paglen; i <= BAD_BLK_OOB_MARK_END; i++) {
157 if (p[i] != BAD_BLK_OOB_MARK_PATT)
158 return -1;
159 }
160 }
161#endif
162
163 return 0;
164}
165
166/**
167 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
168 * @buf: the buffer to search
169 * @td: search pattern descriptor
170 *
171 * Check for a pattern at the given place. Used to search bad block tables and
172 * good / bad block identifiers. Same as check_pattern, but no optional empty
173 * check.
174 */
175static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
176{
177 /* Compare the pattern */
178 if (memcmp(buf + td->offs, td->pattern, td->len))
179 return -1;
180 return 0;
181}
182
183/**
184 * add_marker_len - compute the length of the marker in data area
185 * @td: BBT descriptor used for computation
186 *
187 * The length will be 0 if the marker is located in OOB area.
188 */
189static u32 add_marker_len(struct nand_bbt_descr *td)
190{
191 u32 len;
192
193 if (!(td->options & NAND_BBT_NO_OOB))
194 return 0;
195
196 len = td->len;
197 if (td->options & NAND_BBT_VERSION)
198 len++;
199 return len;
200}
201
202/**
203 * read_bbt - [GENERIC] Read the bad block table starting from page
204 * @mtd: MTD device structure
205 * @buf: temporary buffer
206 * @page: the starting page
207 * @num: the number of bbt descriptors to read
208 * @td: the bbt describtion table
209 * @offs: block number offset in the table
210 *
211 * Read the bad block table starting from page.
212 */
213static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num,
214 struct nand_bbt_descr *td, int offs)
215{
216 int res, ret = 0, i, j, act = 0;
217 struct nand_chip *this = mtd_to_nand(mtd);
218 size_t retlen, len, totlen;
219 loff_t from;
220 int bits = td->options & NAND_BBT_NRBITS_MSK;
221 uint8_t msk = (uint8_t)((1 << bits) - 1);
222 u32 marker_len;
223 int reserved_block_code = td->reserved_block_code;
224
225 totlen = (num * bits) >> 3;
226 marker_len = add_marker_len(td);
227 from = ((loff_t)page) << this->page_shift;
228
229 while (totlen) {
230 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
231 if (marker_len) {
232 /*
233 * In case the BBT marker is not in the OOB area it
234 * will be just in the first page.
235 */
236 len -= marker_len;
237 from += marker_len;
238 marker_len = 0;
239 }
240 res = mtd_read(mtd, from, len, &retlen, buf);
241 if (res < 0) {
242 if (mtd_is_eccerr(res)) {
243 pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
244 from & ~mtd->writesize);
245 return res;
246 } else if (mtd_is_bitflip(res)) {
247 pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
248 from & ~mtd->writesize);
249 ret = res;
250 } else {
251 pr_info("nand_bbt: error reading BBT\n");
252 return res;
253 }
254 }
255
256 /* Analyse data */
257 for (i = 0; i < len; i++) {
258 uint8_t dat = buf[i];
259 for (j = 0; j < 8; j += bits, act++) {
260 uint8_t tmp = (dat >> j) & msk;
261 if (tmp == msk)
262 continue;
263 if (reserved_block_code && (tmp == reserved_block_code)) {
264 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
265 (loff_t)(offs + act) <<
266 this->bbt_erase_shift);
267 bbt_mark_entry(this, offs + act,
268 BBT_BLOCK_RESERVED);
269 mtd->ecc_stats.bbtblocks++;
270 continue;
271 }
272 /*
273 * Leave it for now, if it's matured we can
274 * move this message to pr_debug.
275 */
276 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
277 (loff_t)(offs + act) <<
278 this->bbt_erase_shift);
279 /* Factory marked bad or worn out? */
280 if (tmp == 0)
281 bbt_mark_entry(this, offs + act,
282 BBT_BLOCK_FACTORY_BAD);
283 else
284 bbt_mark_entry(this, offs + act,
285 BBT_BLOCK_WORN);
286 mtd->ecc_stats.badblocks++;
287 }
288 }
289 totlen -= len;
290 from += len;
291 }
292 return ret;
293}
294
295/**
296 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
297 * @mtd: MTD device structure
298 * @buf: temporary buffer
299 * @td: descriptor for the bad block table
300 * @chip: read the table for a specific chip, -1 read all chips; applies only if
301 * NAND_BBT_PERCHIP option is set
302 *
303 * Read the bad block table for all chips starting at a given page. We assume
304 * that the bbt bits are in consecutive order.
305 */
306static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip)
307{
308 struct nand_chip *this = mtd_to_nand(mtd);
309 int res = 0, i;
310
311 if (td->options & NAND_BBT_PERCHIP) {
312 int offs = 0;
313 for (i = 0; i < this->numchips; i++) {
314 if (chip == -1 || chip == i)
315 res = read_bbt(mtd, buf, td->pages[i],
316 this->chipsize >> this->bbt_erase_shift,
317 td, offs);
318 if (res)
319 return res;
320 offs += this->chipsize >> this->bbt_erase_shift;
321 }
322 } else {
323 res = read_bbt(mtd, buf, td->pages[0],
324 mtd->size >> this->bbt_erase_shift, td, 0);
325 if (res)
326 return res;
327 }
328 return 0;
329}
330
331/* BBT marker is in the first page, no OOB */
332static int scan_read_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
333 struct nand_bbt_descr *td)
334{
335 size_t retlen;
336 size_t len;
337
338 len = td->len;
339 if (td->options & NAND_BBT_VERSION)
340 len++;
341
342 return mtd_read(mtd, offs, len, &retlen, buf);
343}
344
345/**
346 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
347 * @mtd: MTD device structure
348 * @buf: temporary buffer
349 * @offs: offset at which to scan
350 * @len: length of data region to read
351 *
352 * Scan read data from data+OOB. May traverse multiple pages, interleaving
353 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
354 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
355 */
356static int scan_read_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
357 size_t len)
358{
359 struct mtd_oob_ops ops;
360 int res, ret = 0;
361
362 ops.mode = MTD_OPS_PLACE_OOB;
363 ops.ooboffs = 0;
364 ops.ooblen = mtd->oobsize;
365
366 while (len > 0) {
367 ops.datbuf = buf;
368 ops.len = min(len, (size_t)mtd->writesize);
369 ops.oobbuf = buf + ops.len;
370
371 res = mtd_read_oob(mtd, offs, &ops);
372 if (res) {
373 if (!mtd_is_bitflip_or_eccerr(res))
374 return res;
375 else if (mtd_is_eccerr(res) || !ret)
376 ret = res;
377 }
378
379 buf += mtd->oobsize + mtd->writesize;
380 len -= mtd->writesize;
381 offs += mtd->writesize;
382 }
383 return ret;
384}
385
386static int scan_read(struct mtd_info *mtd, uint8_t *buf, loff_t offs,
387 size_t len, struct nand_bbt_descr *td)
388{
389 if (td->options & NAND_BBT_NO_OOB)
390 return scan_read_data(mtd, buf, offs, td);
391 else
392 return scan_read_oob(mtd, buf, offs, len);
393}
394
395/* Scan write data with oob to flash */
396static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len,
397 uint8_t *buf, uint8_t *oob)
398{
399 struct mtd_oob_ops ops;
400
401 ops.mode = MTD_OPS_PLACE_OOB;
402 ops.ooboffs = 0;
403 ops.ooblen = mtd->oobsize;
404 ops.datbuf = buf;
405 ops.oobbuf = oob;
406 ops.len = len;
407
408 return mtd_write_oob(mtd, offs, &ops);
409}
410
411static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td)
412{
413 u32 ver_offs = td->veroffs;
414
415 if (!(td->options & NAND_BBT_NO_OOB))
416 ver_offs += mtd->writesize;
417 return ver_offs;
418}
419
420/**
421 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
422 * @mtd: MTD device structure
423 * @buf: temporary buffer
424 * @td: descriptor for the bad block table
425 * @md: descriptor for the bad block table mirror
426 *
427 * Read the bad block table(s) for all chips starting at a given page. We
428 * assume that the bbt bits are in consecutive order.
429 */
430static void read_abs_bbts(struct mtd_info *mtd, uint8_t *buf,
431 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
432{
433 struct nand_chip *this = mtd_to_nand(mtd);
434
435 /* Read the primary version, if available */
436 if (td->options & NAND_BBT_VERSION) {
437 scan_read(mtd, buf, (loff_t)td->pages[0] << this->page_shift,
438 mtd->writesize, td);
439 td->version[0] = buf[bbt_get_ver_offs(mtd, td)];
440 pr_info("Bad block table at page %d, version 0x%02X\n",
441 td->pages[0], td->version[0]);
442 }
443
444 /* Read the mirror version, if available */
445 if (md && (md->options & NAND_BBT_VERSION)) {
446 scan_read(mtd, buf, (loff_t)md->pages[0] << this->page_shift,
447 mtd->writesize, md);
448 md->version[0] = buf[bbt_get_ver_offs(mtd, md)];
449 pr_info("Bad block table at page %d, version 0x%02X\n",
450 md->pages[0], md->version[0]);
451 }
452}
453
454/* Scan a given block partially */
455static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd,
456 loff_t offs, uint8_t *buf, int numpages)
457{
458 struct mtd_oob_ops ops;
459 int j, ret;
460
461 ops.ooblen = mtd->oobsize;
462 ops.oobbuf = buf;
463 ops.ooboffs = 0;
464 ops.datbuf = NULL;
465 ops.mode = MTD_OPS_PLACE_OOB;
466
467 for (j = 0; j < numpages; j++) {
468 /*
469 * Read the full oob until read_oob is fixed to handle single
470 * byte reads for 16 bit buswidth.
471 */
472 ret = mtd_read_oob(mtd, offs, &ops);
473 /* Ignore ECC errors when checking for BBM */
474 if (ret && !mtd_is_bitflip_or_eccerr(ret))
475 return ret;
476
477 if (check_short_pattern(buf, bd))
478 return 1;
479
480 offs += mtd->writesize;
481 }
482 return 0;
483}
484
485/**
486 * create_bbt - [GENERIC] Create a bad block table by scanning the device
487 * @mtd: MTD device structure
488 * @buf: temporary buffer
489 * @bd: descriptor for the good/bad block search pattern
490 * @chip: create the table for a specific chip, -1 read all chips; applies only
491 * if NAND_BBT_PERCHIP option is set
492 *
493 * Create a bad block table by scanning the device for the given good/bad block
494 * identify pattern.
495 */
496static int create_bbt(struct mtd_info *mtd, uint8_t *buf,
497 struct nand_bbt_descr *bd, int chip)
498{
499 struct nand_chip *this = mtd_to_nand(mtd);
500 int i, numblocks, numpages;
501 int startblock;
502 loff_t from;
503
504 pr_info("Scanning device for bad blocks\n");
505
506 if (bd->options & NAND_BBT_SCAN2NDPAGE)
507 numpages = 2;
508 else
509 numpages = 1;
510
511 if (chip == -1) {
512 numblocks = mtd->size >> this->bbt_erase_shift;
513 startblock = 0;
514 from = 0;
515 } else {
516 if (chip >= this->numchips) {
517 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
518 chip + 1, this->numchips);
519 return -EINVAL;
520 }
521 numblocks = this->chipsize >> this->bbt_erase_shift;
522 startblock = chip * numblocks;
523 numblocks += startblock;
524 from = (loff_t)startblock << this->bbt_erase_shift;
525 }
526
527 if (this->bbt_options & NAND_BBT_SCANLASTPAGE)
528 from += mtd->erasesize - (mtd->writesize * numpages);
529
530 for (i = startblock; i < numblocks; i++) {
531 int ret;
532
533 BUG_ON(bd->options & NAND_BBT_NO_OOB);
534
535 ret = scan_block_fast(mtd, bd, from, buf, numpages);
536 if (ret < 0)
537 return ret;
538
539 if (ret) {
540 bbt_mark_entry(this, i, BBT_BLOCK_FACTORY_BAD);
541 pr_warn("Bad eraseblock %d at 0x%012llx\n",
542 i, (unsigned long long)from);
543 mtd->ecc_stats.badblocks++;
544 }
545
546 from += (1 << this->bbt_erase_shift);
547 }
548 return 0;
549}
550
551/**
552 * search_bbt - [GENERIC] scan the device for a specific bad block table
553 * @mtd: MTD device structure
554 * @buf: temporary buffer
555 * @td: descriptor for the bad block table
556 *
557 * Read the bad block table by searching for a given ident pattern. Search is
558 * preformed either from the beginning up or from the end of the device
559 * downwards. The search starts always at the start of a block. If the option
560 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
561 * the bad block information of this chip. This is necessary to provide support
562 * for certain DOC devices.
563 *
564 * The bbt ident pattern resides in the oob area of the first page in a block.
565 */
566static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td)
567{
568 struct nand_chip *this = mtd_to_nand(mtd);
569 int i, chips;
570 int startblock, block, dir;
571 int scanlen = mtd->writesize + mtd->oobsize;
572 int bbtblocks;
573 int blocktopage = this->bbt_erase_shift - this->page_shift;
574
575 /* Search direction top -> down? */
576 if (td->options & NAND_BBT_LASTBLOCK) {
577 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
578 dir = -1;
579 } else {
580 startblock = 0;
581 dir = 1;
582 }
583
584 /* Do we have a bbt per chip? */
585 if (td->options & NAND_BBT_PERCHIP) {
586 chips = this->numchips;
587 bbtblocks = this->chipsize >> this->bbt_erase_shift;
588 startblock &= bbtblocks - 1;
589 } else {
590 chips = 1;
591 bbtblocks = mtd->size >> this->bbt_erase_shift;
592 }
593
594 for (i = 0; i < chips; i++) {
595 /* Reset version information */
596 td->version[i] = 0;
597 td->pages[i] = -1;
598 /* Scan the maximum number of blocks */
599 for (block = 0; block < td->maxblocks; block++) {
600
601 int actblock = startblock + dir * block;
602 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
603
604 /* Read first page */
605 scan_read(mtd, buf, offs, mtd->writesize, td);
606#if CUSTOMIZED_BBT
607 if (!check_pattern(mtd, buf, scanlen, mtd->writesize, td)) {
608#else
609 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
610#endif
611 td->pages[i] = actblock << blocktopage;
612 if (td->options & NAND_BBT_VERSION) {
613 offs = bbt_get_ver_offs(mtd, td);
614 td->version[i] = buf[offs];
615 }
616 break;
617 }
618 }
619 startblock += this->chipsize >> this->bbt_erase_shift;
620 }
621 /* Check, if we found a bbt for each requested chip */
622 for (i = 0; i < chips; i++) {
623 if (td->pages[i] == -1)
624 pr_warn("Bad block table not found for chip %d\n", i);
625 else
626 pr_info("Bad block table found at page %d, version 0x%02X\n",
627 td->pages[i], td->version[i]);
628 }
629 return 0;
630}
631
632/**
633 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
634 * @mtd: MTD device structure
635 * @buf: temporary buffer
636 * @td: descriptor for the bad block table
637 * @md: descriptor for the bad block table mirror
638 *
639 * Search and read the bad block table(s).
640 */
641static void search_read_bbts(struct mtd_info *mtd, uint8_t *buf,
642 struct nand_bbt_descr *td,
643 struct nand_bbt_descr *md)
644{
645 /* Search the primary table */
646 search_bbt(mtd, buf, td);
647
648 /* Search the mirror table */
649 if (md)
650 search_bbt(mtd, buf, md);
651}
652
653/**
654 * get_bbt_block - Get the first valid eraseblock suitable to store a BBT
655 * @this: the NAND device
656 * @td: the BBT description
657 * @md: the mirror BBT descriptor
658 * @chip: the CHIP selector
659 *
660 * This functions returns a positive block number pointing a valid eraseblock
661 * suitable to store a BBT (i.e. in the range reserved for BBT), or -ENOSPC if
662 * all blocks are already used of marked bad. If td->pages[chip] was already
663 * pointing to a valid block we re-use it, otherwise we search for the next
664 * valid one.
665 */
666static int get_bbt_block(struct nand_chip *this, struct nand_bbt_descr *td,
667 struct nand_bbt_descr *md, int chip)
668{
669 int startblock, dir, page, numblocks, i;
670
671 /*
672 * There was already a version of the table, reuse the page. This
673 * applies for absolute placement too, as we have the page number in
674 * td->pages.
675 */
676 if (td->pages[chip] != -1)
677 return td->pages[chip] >>
678 (this->bbt_erase_shift - this->page_shift);
679
680 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
681 if (!(td->options & NAND_BBT_PERCHIP))
682 numblocks *= this->numchips;
683
684 /*
685 * Automatic placement of the bad block table. Search direction
686 * top -> down?
687 */
688 if (td->options & NAND_BBT_LASTBLOCK) {
689 startblock = numblocks * (chip + 1) - 1;
690 dir = -1;
691 } else {
692 startblock = chip * numblocks;
693 dir = 1;
694 }
695
696 for (i = 0; i < td->maxblocks; i++) {
697 int block = startblock + dir * i;
698
699 /* Check, if the block is bad */
700 switch (bbt_get_entry(this, block)) {
701 case BBT_BLOCK_WORN:
702 case BBT_BLOCK_FACTORY_BAD:
703 continue;
704 }
705
706 page = block << (this->bbt_erase_shift - this->page_shift);
707
708 /* Check, if the block is used by the mirror table */
709 if (!md || md->pages[chip] != page)
710 return block;
711 }
712
713 return -ENOSPC;
714}
715
716/**
717 * mark_bbt_block_bad - Mark one of the block reserved for BBT bad
718 * @this: the NAND device
719 * @td: the BBT description
720 * @chip: the CHIP selector
721 * @block: the BBT block to mark
722 *
723 * Blocks reserved for BBT can become bad. This functions is an helper to mark
724 * such blocks as bad. It takes care of updating the in-memory BBT, marking the
725 * block as bad using a bad block marker and invalidating the associated
726 * td->pages[] entry.
727 */
728static void mark_bbt_block_bad(struct nand_chip *this,
729 struct nand_bbt_descr *td,
730 int chip, int block)
731{
732 struct mtd_info *mtd = nand_to_mtd(this);
733 loff_t to;
734 int res;
735
736 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
737
738 to = (loff_t)block << this->bbt_erase_shift;
739 res = this->block_markbad(mtd, to);
740 if (res)
741 pr_warn("nand_bbt: error %d while marking block %d bad\n",
742 res, block);
743
744 td->pages[chip] = -1;
745}
746
747/**
748 * write_bbt - [GENERIC] (Re)write the bad block table
749 * @mtd: MTD device structure
750 * @buf: temporary buffer
751 * @td: descriptor for the bad block table
752 * @md: descriptor for the bad block table mirror
753 * @chipsel: selector for a specific chip, -1 for all
754 *
755 * (Re)write the bad block table.
756 */
757static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
758 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
759 int chipsel)
760{
761 struct nand_chip *this = mtd_to_nand(mtd);
762 struct erase_info einfo;
763 int i, res, chip = 0;
764 int bits, page, offs, numblocks, sft, sftmsk;
765 int nrchips, pageoffs, ooboffs;
766 uint8_t msk[4];
767 uint8_t rcode = td->reserved_block_code;
768 size_t retlen, len = 0;
769 loff_t to;
770 struct mtd_oob_ops ops;
771
772 ops.ooblen = mtd->oobsize;
773 ops.ooboffs = 0;
774 ops.datbuf = NULL;
775 ops.mode = MTD_OPS_PLACE_OOB;
776
777 if (!rcode)
778 rcode = 0xff;
779 /* Write bad block table per chip rather than per device? */
780 if (td->options & NAND_BBT_PERCHIP) {
781 numblocks = (int)(this->chipsize >> this->bbt_erase_shift);
782 /* Full device write or specific chip? */
783 if (chipsel == -1) {
784 nrchips = this->numchips;
785 } else {
786 nrchips = chipsel + 1;
787 chip = chipsel;
788 }
789 } else {
790 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
791 nrchips = 1;
792 }
793
794 /* Loop through the chips */
795 while (chip < nrchips) {
796 int block;
797
798 block = get_bbt_block(this, td, md, chip);
799 if (block < 0) {
800 pr_err("No space left to write bad block table\n");
801 res = block;
802 goto outerr;
803 }
804
805 /*
806 * get_bbt_block() returns a block number, shift the value to
807 * get a page number.
808 */
809 page = block << (this->bbt_erase_shift - this->page_shift);
810
811 /* Set up shift count and masks for the flash table */
812 bits = td->options & NAND_BBT_NRBITS_MSK;
813 msk[2] = ~rcode;
814 switch (bits) {
815 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
816 msk[3] = 0x01;
817 break;
818 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
819 msk[3] = 0x03;
820 break;
821 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
822 msk[3] = 0x0f;
823 break;
824 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
825 msk[3] = 0xff;
826 break;
827 default: return -EINVAL;
828 }
829
830 to = ((loff_t)page) << this->page_shift;
831
832 /* Must we save the block contents? */
833 if (td->options & NAND_BBT_SAVECONTENT) {
834 /* Make it block aligned */
835 to &= ~(((loff_t)1 << this->bbt_erase_shift) - 1);
836 len = 1 << this->bbt_erase_shift;
837 res = mtd_read(mtd, to, len, &retlen, buf);
838 if (res < 0) {
839 if (retlen != len) {
840 pr_info("nand_bbt: error reading block for writing the bad block table\n");
841 return res;
842 }
843 pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
844 }
845 /* Read oob data */
846 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
847 ops.oobbuf = &buf[len];
848 res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
849 if (res < 0 || ops.oobretlen != ops.ooblen)
850 goto outerr;
851
852 /* Calc the byte offset in the buffer */
853 pageoffs = page - (int)(to >> this->page_shift);
854 offs = pageoffs << this->page_shift;
855 /* Preset the bbt area with 0xff */
856 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
857 ooboffs = len + (pageoffs * mtd->oobsize);
858
859 } else if (td->options & NAND_BBT_NO_OOB) {
860 ooboffs = 0;
861 offs = td->len;
862 /* The version byte */
863 if (td->options & NAND_BBT_VERSION)
864 offs++;
865 /* Calc length */
866 len = (size_t)(numblocks >> sft);
867 len += offs;
868 /* Make it page aligned! */
869 len = ALIGN(len, mtd->writesize);
870 /* Preset the buffer with 0xff */
871 memset(buf, 0xff, len);
872 /* Pattern is located at the begin of first page */
873 memcpy(buf, td->pattern, td->len);
874 } else {
875 /* Calc length */
876 len = (size_t)(numblocks >> sft);
877 /* Make it page aligned! */
878 len = ALIGN(len, mtd->writesize);
879 /* Preset the buffer with 0xff */
880 memset(buf, 0xff, len +
881 (len >> this->page_shift)* mtd->oobsize);
882 offs = 0;
883 ooboffs = len;
884 /* Pattern is located in oob area of first page */
885 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
886 }
887
888 if (td->options & NAND_BBT_VERSION)
889 buf[ooboffs + td->veroffs] = td->version[chip];
890
891 /* Walk through the memory table */
892 for (i = 0; i < numblocks; i++) {
893 uint8_t dat;
894 int sftcnt = (i << (3 - sft)) & sftmsk;
895 dat = bbt_get_entry(this, chip * numblocks + i);
896 /* Do not store the reserved bbt blocks! */
897 buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
898 }
899
900 memset(&einfo, 0, sizeof(einfo));
901 einfo.mtd = mtd;
902 einfo.addr = to;
903 einfo.len = 1 << this->bbt_erase_shift;
904 res = nand_erase_nand(mtd, &einfo, 1);
905 if (res < 0) {
906 pr_warn("nand_bbt: error while erasing BBT block %d\n",
907 res);
908 mark_bbt_block_bad(this, td, chip, block);
909 continue;
910 }
911
912 res = scan_write_bbt(mtd, to, len, buf,
913 td->options & NAND_BBT_NO_OOB ? NULL :
914 &buf[len]);
915 if (res < 0) {
916 pr_warn("nand_bbt: error while writing BBT block %d\n",
917 res);
918 mark_bbt_block_bad(this, td, chip, block);
919 continue;
920 }
921
922 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
923 (unsigned long long)to, td->version[chip]);
924
925 /* Mark it as used */
926 td->pages[chip++] = page;
927 }
928 return 0;
929
930 outerr:
931 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
932 return res;
933}
934
935/**
936 * nand_memory_bbt - [GENERIC] create a memory based bad block table
937 * @mtd: MTD device structure
938 * @bd: descriptor for the good/bad block search pattern
939 *
940 * The function creates a memory based bbt by scanning the device for
941 * manufacturer / software marked good / bad blocks.
942 */
943static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
944{
945 struct nand_chip *this = mtd_to_nand(mtd);
946
947 return create_bbt(mtd, this->buffers->databuf, bd, -1);
948}
949
950/**
951 * check_create - [GENERIC] create and write bbt(s) if necessary
952 * @mtd: MTD device structure
953 * @buf: temporary buffer
954 * @bd: descriptor for the good/bad block search pattern
955 *
956 * The function checks the results of the previous call to read_bbt and creates
957 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
958 * for the chip/device. Update is necessary if one of the tables is missing or
959 * the version nr. of one table is less than the other.
960 */
961static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd)
962{
963 int i, chips, writeops, create, chipsel, res, res2;
964 struct nand_chip *this = mtd_to_nand(mtd);
965 struct nand_bbt_descr *td = this->bbt_td;
966 struct nand_bbt_descr *md = this->bbt_md;
967 struct nand_bbt_descr *rd, *rd2;
968
969 /* Do we have a bbt per chip? */
970 if (td->options & NAND_BBT_PERCHIP)
971 chips = this->numchips;
972 else
973 chips = 1;
974
975 for (i = 0; i < chips; i++) {
976 writeops = 0;
977 create = 0;
978 rd = NULL;
979 rd2 = NULL;
980 res = res2 = 0;
981 /* Per chip or per device? */
982 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
983 /* Mirrored table available? */
984 if (md) {
985 if (td->pages[i] == -1 && md->pages[i] == -1) {
986 create = 1;
987 writeops = 0x03;
988 } else if (td->pages[i] == -1) {
989 rd = md;
990 writeops = 0x01;
991 } else if (md->pages[i] == -1) {
992 rd = td;
993 writeops = 0x02;
994 } else if (td->version[i] == md->version[i]) {
995 rd = td;
996 if (!(td->options & NAND_BBT_VERSION))
997 rd2 = md;
998 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
999 rd = td;
1000 writeops = 0x02;
1001 } else {
1002 rd = md;
1003 writeops = 0x01;
1004 }
1005 } else {
1006 if (td->pages[i] == -1) {
1007 create = 1;
1008 writeops = 0x01;
1009 } else {
1010 rd = td;
1011 }
1012 }
1013
1014 if (create) {
1015 /* Create the bad block table by scanning the device? */
1016 if (!(td->options & NAND_BBT_CREATE))
1017 continue;
1018
1019 /* Create the table in memory by scanning the chip(s) */
1020 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
1021 create_bbt(mtd, buf, bd, chipsel);
1022
1023 td->version[i] = 1;
1024 if (md)
1025 md->version[i] = 1;
1026 }
1027
1028 /* Read back first? */
1029 if (rd) {
1030 res = read_abs_bbt(mtd, buf, rd, chipsel);
1031 if (mtd_is_eccerr(res)) {
1032 /* Mark table as invalid */
1033 rd->pages[i] = -1;
1034 rd->version[i] = 0;
1035 i--;
1036 continue;
1037 }
1038 }
1039 /* If they weren't versioned, read both */
1040 if (rd2) {
1041 res2 = read_abs_bbt(mtd, buf, rd2, chipsel);
1042 if (mtd_is_eccerr(res2)) {
1043 /* Mark table as invalid */
1044 rd2->pages[i] = -1;
1045 rd2->version[i] = 0;
1046 i--;
1047 continue;
1048 }
1049 }
1050
1051 /* Scrub the flash table(s)? */
1052 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
1053 writeops = 0x03;
1054
1055 /* Update version numbers before writing */
1056 if (md) {
1057 td->version[i] = max(td->version[i], md->version[i]);
1058 md->version[i] = td->version[i];
1059 }
1060
1061 /* Write the bad block table to the device? */
1062 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1063 res = write_bbt(mtd, buf, td, md, chipsel);
1064 if (res < 0)
1065 return res;
1066 }
1067
1068 /* Write the mirror bad block table to the device? */
1069 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1070 res = write_bbt(mtd, buf, md, td, chipsel);
1071 if (res < 0)
1072 return res;
1073 }
1074 }
1075 return 0;
1076}
1077
1078/**
1079 * mark_bbt_regions - [GENERIC] mark the bad block table regions
1080 * @mtd: MTD device structure
1081 * @td: bad block table descriptor
1082 *
1083 * The bad block table regions are marked as "bad" to prevent accidental
1084 * erasures / writes. The regions are identified by the mark 0x02.
1085 */
1086static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td)
1087{
1088 struct nand_chip *this = mtd_to_nand(mtd);
1089 int i, j, chips, block, nrblocks, update;
1090 uint8_t oldval;
1091
1092 /* Do we have a bbt per chip? */
1093 if (td->options & NAND_BBT_PERCHIP) {
1094 chips = this->numchips;
1095 nrblocks = (int)(this->chipsize >> this->bbt_erase_shift);
1096 } else {
1097 chips = 1;
1098 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1099 }
1100
1101 for (i = 0; i < chips; i++) {
1102 if ((td->options & NAND_BBT_ABSPAGE) ||
1103 !(td->options & NAND_BBT_WRITE)) {
1104 if (td->pages[i] == -1)
1105 continue;
1106 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1107 oldval = bbt_get_entry(this, block);
1108 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1109 if ((oldval != BBT_BLOCK_RESERVED) &&
1110 td->reserved_block_code)
1111 nand_update_bbt(mtd, (loff_t)block <<
1112 this->bbt_erase_shift);
1113 continue;
1114 }
1115 update = 0;
1116 if (td->options & NAND_BBT_LASTBLOCK)
1117 block = ((i + 1) * nrblocks) - td->maxblocks;
1118 else
1119 block = i * nrblocks;
1120 for (j = 0; j < td->maxblocks; j++) {
1121 oldval = bbt_get_entry(this, block);
1122 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1123 if (oldval != BBT_BLOCK_RESERVED)
1124 update = 1;
1125 block++;
1126 }
1127 /*
1128 * If we want reserved blocks to be recorded to flash, and some
1129 * new ones have been marked, then we need to update the stored
1130 * bbts. This should only happen once.
1131 */
1132 if (update && td->reserved_block_code)
1133 nand_update_bbt(mtd, (loff_t)(block - 1) <<
1134 this->bbt_erase_shift);
1135 }
1136}
1137
1138/**
1139 * verify_bbt_descr - verify the bad block description
1140 * @mtd: MTD device structure
1141 * @bd: the table to verify
1142 *
1143 * This functions performs a few sanity checks on the bad block description
1144 * table.
1145 */
1146static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1147{
1148 struct nand_chip *this = mtd_to_nand(mtd);
1149 u32 pattern_len;
1150 u32 bits;
1151 u32 table_size;
1152
1153 if (!bd)
1154 return;
1155
1156 pattern_len = bd->len;
1157 bits = bd->options & NAND_BBT_NRBITS_MSK;
1158
1159 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1160 !(this->bbt_options & NAND_BBT_USE_FLASH));
1161 BUG_ON(!bits);
1162
1163 if (bd->options & NAND_BBT_VERSION)
1164 pattern_len++;
1165
1166 if (bd->options & NAND_BBT_NO_OOB) {
1167 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1168 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1169 BUG_ON(bd->offs);
1170 if (bd->options & NAND_BBT_VERSION)
1171 BUG_ON(bd->veroffs != bd->len);
1172 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1173 }
1174
1175 if (bd->options & NAND_BBT_PERCHIP)
1176 table_size = this->chipsize >> this->bbt_erase_shift;
1177 else
1178 table_size = mtd->size >> this->bbt_erase_shift;
1179 table_size >>= 3;
1180 table_size *= bits;
1181 if (bd->options & NAND_BBT_NO_OOB)
1182 table_size += pattern_len;
1183 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1184}
1185
1186/**
1187 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1188 * @mtd: MTD device structure
1189 * @bd: descriptor for the good/bad block search pattern
1190 *
1191 * The function checks, if a bad block table(s) is/are already available. If
1192 * not it scans the device for manufacturer marked good / bad blocks and writes
1193 * the bad block table(s) to the selected place.
1194 *
1195 * The bad block table memory is allocated here. It must be freed by calling
1196 * the nand_free_bbt function.
1197 */
1198static int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
1199{
1200 struct nand_chip *this = mtd_to_nand(mtd);
1201 int len, res;
1202 uint8_t *buf;
1203 struct nand_bbt_descr *td = this->bbt_td;
1204 struct nand_bbt_descr *md = this->bbt_md;
1205
1206 len = (mtd->size >> (this->bbt_erase_shift + 2)) ? : 1;
1207 /*
1208 * Allocate memory (2bit per block) and clear the memory bad block
1209 * table.
1210 */
1211 this->bbt = kzalloc(len, GFP_KERNEL);
1212 if (!this->bbt)
1213 return -ENOMEM;
1214
1215 /*
1216 * If no primary table decriptor is given, scan the device to build a
1217 * memory based bad block table.
1218 */
1219 if (!td) {
1220 if ((res = nand_memory_bbt(mtd, bd))) {
1221 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1222 goto err;
1223 }
1224 return 0;
1225 }
1226 verify_bbt_descr(mtd, td);
1227 verify_bbt_descr(mtd, md);
1228
1229 /* Allocate a temporary buffer for one eraseblock incl. oob */
1230 len = (1 << this->bbt_erase_shift);
1231 len += (len >> this->page_shift) * mtd->oobsize;
1232 buf = vmalloc(len);
1233 if (!buf) {
1234 res = -ENOMEM;
1235 goto err;
1236 }
1237
1238 /* Is the bbt at a given page? */
1239 if (td->options & NAND_BBT_ABSPAGE) {
1240 read_abs_bbts(mtd, buf, td, md);
1241 } else {
1242 /* Search the bad block table using a pattern in oob */
1243 search_read_bbts(mtd, buf, td, md);
1244 }
1245
1246 res = check_create(mtd, buf, bd);
1247 if (res)
1248 goto err;
1249
1250 /* Prevent the bbt regions from erasing / writing */
1251 mark_bbt_region(mtd, td);
1252 if (md)
1253 mark_bbt_region(mtd, md);
1254
1255 vfree(buf);
1256 return 0;
1257
1258err:
1259 kfree(this->bbt);
1260 this->bbt = NULL;
1261 return res;
1262}
1263
1264/**
1265 * nand_update_bbt - update bad block table(s)
1266 * @mtd: MTD device structure
1267 * @offs: the offset of the newly marked block
1268 *
1269 * The function updates the bad block table(s).
1270 */
1271static int nand_update_bbt(struct mtd_info *mtd, loff_t offs)
1272{
1273 struct nand_chip *this = mtd_to_nand(mtd);
1274 int len, res = 0;
1275 int chip, chipsel;
1276 uint8_t *buf;
1277 struct nand_bbt_descr *td = this->bbt_td;
1278 struct nand_bbt_descr *md = this->bbt_md;
1279
1280 if (!this->bbt || !td)
1281 return -EINVAL;
1282
1283 /* Allocate a temporary buffer for one eraseblock incl. oob */
1284 len = (1 << this->bbt_erase_shift);
1285 len += (len >> this->page_shift) * mtd->oobsize;
1286 buf = kmalloc(len, GFP_KERNEL);
1287 if (!buf)
1288 return -ENOMEM;
1289
1290 /* Do we have a bbt per chip? */
1291 if (td->options & NAND_BBT_PERCHIP) {
1292 chip = (int)(offs >> this->chip_shift);
1293 chipsel = chip;
1294 } else {
1295 chip = 0;
1296 chipsel = -1;
1297 }
1298
1299 td->version[chip]++;
1300 if (md)
1301 md->version[chip]++;
1302
1303 /* Write the bad block table to the device? */
1304 if (td->options & NAND_BBT_WRITE) {
1305 res = write_bbt(mtd, buf, td, md, chipsel);
1306 if (res < 0)
1307 goto out;
1308 }
1309 /* Write the mirror bad block table to the device? */
1310 if (md && (md->options & NAND_BBT_WRITE)) {
1311 res = write_bbt(mtd, buf, md, td, chipsel);
1312 }
1313
1314 out:
1315 kfree(buf);
1316 return res;
1317}
1318
1319/*
1320 * Define some generic bad / good block scan pattern which are used
1321 * while scanning a device for factory marked good / bad blocks.
1322 */
1323static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1324
1325/* Generic flash bbt descriptors */
1326//#if CUSTOMIZED_BBT /*ctc*/
1327//static uint8_t bbt_pattern[] = {'A', 'R', 'C', 'A' };
1328//static uint8_t mirror_pattern[] = {'a', 'c', 'r', 'a' };
1329//#else
1330static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1331static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1332//#endif
1333
1334static struct nand_bbt_descr bbt_main_descr = {
1335 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1336 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1337 .offs = 8,
1338 .len = 4,
1339 .veroffs = 12,
1340 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1341 .pattern = bbt_pattern
1342};
1343
1344static struct nand_bbt_descr bbt_mirror_descr = {
1345 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1346 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1347 .offs = 8,
1348 .len = 4,
1349 .veroffs = 12,
1350 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1351 .pattern = mirror_pattern
1352};
1353
1354static struct nand_bbt_descr bbt_main_no_oob_descr = {
1355 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1356 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1357 | NAND_BBT_NO_OOB,
1358 .len = 4,
1359 .veroffs = 4,
1360 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1361 .pattern = bbt_pattern
1362};
1363
1364static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1365 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1366 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1367 | NAND_BBT_NO_OOB,
1368 .len = 4,
1369 .veroffs = 4,
1370 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1371 .pattern = mirror_pattern
1372};
1373
1374#define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1375/**
1376 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1377 * @this: NAND chip to create descriptor for
1378 *
1379 * This function allocates and initializes a nand_bbt_descr for BBM detection
1380 * based on the properties of @this. The new descriptor is stored in
1381 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1382 * passed to this function.
1383 */
1384static int nand_create_badblock_pattern(struct nand_chip *this)
1385{
1386 struct nand_bbt_descr *bd;
1387 if (this->badblock_pattern) {
1388 pr_warn("Bad block pattern already allocated; not replacing\n");
1389 return -EINVAL;
1390 }
1391 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1392 if (!bd)
1393 return -ENOMEM;
1394
1395#if CUSTOMIZED_BBT /*ctc*/
1396 if (of_get_customized_bbt_from_chip(this)) {
1397 bd->options = 0 & BADBLOCK_SCAN_MASK;
1398 } else {
1399 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1400 }
1401#else
1402 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1403#endif
1404 bd->offs = this->badblockpos;
1405 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1406 bd->pattern = scan_ff_pattern;
1407 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1408 this->badblock_pattern = bd;
1409 return 0;
1410}
1411
1412/**
1413 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1414 * @mtd: MTD device structure
1415 *
1416 * This function selects the default bad block table support for the device and
1417 * calls the nand_scan_bbt function.
1418 */
1419int nand_default_bbt(struct mtd_info *mtd)
1420{
1421 struct nand_chip *this = mtd_to_nand(mtd);
1422 int ret;
1423/* change the generic bad / good block scan pattern if of_get_customized_bbt_from_chip(this) true */
1424#if CUSTOMIZED_BBT
1425 if(of_get_customized_bbt_from_chip(this)) {
1426 bbt_pattern[0] = 'A';
1427 bbt_pattern[1] = 'R';
1428 bbt_pattern[2] = 'C';
1429 bbt_pattern[3] = 'A';
1430 mirror_pattern[0] = 'a';
1431 mirror_pattern[1] = 'c';
1432 mirror_pattern[2] = 'r';
1433 mirror_pattern[3] = 'a';
1434 }
1435#endif
1436
1437 /* Is a flash based bad block table requested? */
1438 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1439 /* Use the default pattern descriptors */
1440 if (!this->bbt_td) {
1441 if (this->bbt_options & NAND_BBT_NO_OOB) {
1442 this->bbt_td = &bbt_main_no_oob_descr;
1443 this->bbt_md = &bbt_mirror_no_oob_descr;
1444 } else {
1445 this->bbt_td = &bbt_main_descr;
1446 this->bbt_md = &bbt_mirror_descr;
1447 }
1448 }
1449 } else {
1450 this->bbt_td = NULL;
1451 this->bbt_md = NULL;
1452 }
1453
1454 if (!this->badblock_pattern) {
1455 ret = nand_create_badblock_pattern(this);
1456 if (ret)
1457 return ret;
1458 }
1459
1460 return nand_scan_bbt(mtd, this->badblock_pattern);
1461}
1462
1463/**
1464 * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
1465 * @mtd: MTD device structure
1466 * @offs: offset in the device
1467 */
1468int nand_isreserved_bbt(struct mtd_info *mtd, loff_t offs)
1469{
1470 struct nand_chip *this = mtd_to_nand(mtd);
1471 int block;
1472
1473 block = (int)(offs >> this->bbt_erase_shift);
1474 return bbt_get_entry(this, block) == BBT_BLOCK_RESERVED;
1475}
1476
1477/**
1478 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1479 * @mtd: MTD device structure
1480 * @offs: offset in the device
1481 * @allowbbt: allow access to bad block table region
1482 */
1483int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
1484{
1485 struct nand_chip *this = mtd_to_nand(mtd);
1486 int block, res;
1487
1488 block = (int)(offs >> this->bbt_erase_shift);
1489 res = bbt_get_entry(this, block);
1490
1491 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1492 (unsigned int)offs, block, res);
1493
1494 switch (res) {
1495 case BBT_BLOCK_GOOD:
1496 return 0;
1497 case BBT_BLOCK_WORN:
1498 return 1;
1499 case BBT_BLOCK_RESERVED:
1500 return allowbbt ? 0 : 1;
1501 }
1502 return 1;
1503}
1504
1505/**
1506 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1507 * @mtd: MTD device structure
1508 * @offs: offset of the bad block
1509 */
1510int nand_markbad_bbt(struct mtd_info *mtd, loff_t offs)
1511{
1512 struct nand_chip *this = mtd_to_nand(mtd);
1513 int block, ret = 0;
1514
1515 block = (int)(offs >> this->bbt_erase_shift);
1516
1517 /* Mark bad block in memory */
1518 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
1519
1520 /* Update flash-based bad block table */
1521 if (this->bbt_options & NAND_BBT_USE_FLASH)
1522 ret = nand_update_bbt(mtd, offs);
1523
1524 return ret;
1525}