1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Overview:
4 * Bad block table support for the NAND driver
5 *
6 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
7 *
8 * Description:
9 *
10 * When nand_scan_bbt is called, then it tries to find the bad block table
11 * depending on the options in the BBT descriptor(s). If no flash based BBT
12 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
13 * marked good / bad blocks. This information is used to create a memory BBT.
14 * Once a new bad block is discovered then the "factory" information is updated
15 * on the device.
16 * If a flash based BBT is specified then the function first tries to find the
17 * BBT on flash. If a BBT is found then the contents are read and the memory
18 * based BBT is created. If a mirrored BBT is selected then the mirror is
19 * searched too and the versions are compared. If the mirror has a greater
20 * version number, then the mirror BBT is used to build the memory based BBT.
21 * If the tables are not versioned, then we "or" the bad block information.
22 * If one of the BBTs is out of date or does not exist it is (re)created.
23 * If no BBT exists at all then the device is scanned for factory marked
24 * good / bad blocks and the bad block tables are created.
25 *
26 * For manufacturer created BBTs like the one found on M-SYS DOC devices
27 * the BBT is searched and read but never created
28 *
29 * The auto generated bad block table is located in the last good blocks
30 * of the device. The table is mirrored, so it can be updated eventually.
31 * The table is marked in the OOB area with an ident pattern and a version
32 * number which indicates which of both tables is more up to date. If the NAND
33 * controller needs the complete OOB area for the ECC information then the
34 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
35 * course): it moves the ident pattern and the version byte into the data area
36 * and the OOB area will remain untouched.
37 *
38 * The table uses 2 bits per block
39 * 11b: block is good
40 * 00b: block is factory marked bad
41 * 01b, 10b: block is marked bad due to wear
42 *
43 * The memory bad block table uses the following scheme:
44 * 00b: block is good
45 * 01b: block is marked bad due to wear
46 * 10b: block is reserved (to protect the bbt area)
47 * 11b: block is factory marked bad
48 *
49 * Multichip devices like DOC store the bad block info per floor.
50 *
51 * Following assumptions are made:
52 * - bbts start at a page boundary, if autolocated on a block boundary
53 * - the space necessary for a bbt in FLASH does not exceed a block boundary
54 */
55
56 #include <linux/slab.h>
57 #include <linux/types.h>
58 #include <linux/mtd/mtd.h>
59 #include <linux/mtd/bbm.h>
60 #include <linux/bitops.h>
61 #include <linux/delay.h>
62 #include <linux/vmalloc.h>
63 #include <linux/export.h>
64 #include <linux/string.h>
65
66 #include "internals.h"
67
68 #define BBT_BLOCK_GOOD 0x00
69 #define BBT_BLOCK_WORN 0x01
70 #define BBT_BLOCK_RESERVED 0x02
71 #define BBT_BLOCK_FACTORY_BAD 0x03
72
73 #define BBT_ENTRY_MASK 0x03
74 #define BBT_ENTRY_SHIFT 2
75
bbt_get_entry(struct nand_chip * chip,int block)76 static inline uint8_t bbt_get_entry(struct nand_chip *chip, int block)
77 {
78 uint8_t entry = chip->bbt[block >> BBT_ENTRY_SHIFT];
79 entry >>= (block & BBT_ENTRY_MASK) * 2;
80 return entry & BBT_ENTRY_MASK;
81 }
82
bbt_mark_entry(struct nand_chip * chip,int block,uint8_t mark)83 static inline void bbt_mark_entry(struct nand_chip *chip, int block,
84 uint8_t mark)
85 {
86 uint8_t msk = (mark & BBT_ENTRY_MASK) << ((block & BBT_ENTRY_MASK) * 2);
87 chip->bbt[block >> BBT_ENTRY_SHIFT] |= msk;
88 }
89
check_pattern_no_oob(uint8_t * buf,struct nand_bbt_descr * td)90 static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
91 {
92 if (memcmp(buf, td->pattern, td->len))
93 return -1;
94 return 0;
95 }
96
97 /**
98 * check_pattern - [GENERIC] check if a pattern is in the buffer
99 * @buf: the buffer to search
100 * @len: the length of buffer to search
101 * @paglen: the pagelength
102 * @td: search pattern descriptor
103 *
104 * Check for a pattern at the given place. Used to search bad block tables and
105 * good / bad block identifiers.
106 */
check_pattern(uint8_t * buf,int len,int paglen,struct nand_bbt_descr * td)107 static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td)
108 {
109 if (td->options & NAND_BBT_NO_OOB)
110 return check_pattern_no_oob(buf, td);
111
112 /* Compare the pattern */
113 if (memcmp(buf + paglen + td->offs, td->pattern, td->len))
114 return -1;
115
116 return 0;
117 }
118
119 /**
120 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
121 * @buf: the buffer to search
122 * @td: search pattern descriptor
123 *
124 * Check for a pattern at the given place. Used to search bad block tables and
125 * good / bad block identifiers. Same as check_pattern, but no optional empty
126 * check.
127 */
check_short_pattern(uint8_t * buf,struct nand_bbt_descr * td)128 static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
129 {
130 /* Compare the pattern */
131 if (memcmp(buf + td->offs, td->pattern, td->len))
132 return -1;
133 return 0;
134 }
135
136 /**
137 * add_marker_len - compute the length of the marker in data area
138 * @td: BBT descriptor used for computation
139 *
140 * The length will be 0 if the marker is located in OOB area.
141 */
add_marker_len(struct nand_bbt_descr * td)142 static u32 add_marker_len(struct nand_bbt_descr *td)
143 {
144 u32 len;
145
146 if (!(td->options & NAND_BBT_NO_OOB))
147 return 0;
148
149 len = td->len;
150 if (td->options & NAND_BBT_VERSION)
151 len++;
152 return len;
153 }
154
155 /**
156 * read_bbt - [GENERIC] Read the bad block table starting from page
157 * @this: NAND chip object
158 * @buf: temporary buffer
159 * @page: the starting page
160 * @num: the number of bbt descriptors to read
161 * @td: the bbt describtion table
162 * @offs: block number offset in the table
163 *
164 * Read the bad block table starting from page.
165 */
read_bbt(struct nand_chip * this,uint8_t * buf,int page,int num,struct nand_bbt_descr * td,int offs)166 static int read_bbt(struct nand_chip *this, uint8_t *buf, int page, int num,
167 struct nand_bbt_descr *td, int offs)
168 {
169 struct mtd_info *mtd = nand_to_mtd(this);
170 int res, ret = 0, i, j, act = 0;
171 size_t retlen, len, totlen;
172 loff_t from;
173 int bits = td->options & NAND_BBT_NRBITS_MSK;
174 uint8_t msk = (uint8_t)((1 << bits) - 1);
175 u32 marker_len;
176 int reserved_block_code = td->reserved_block_code;
177
178 totlen = (num * bits) >> 3;
179 marker_len = add_marker_len(td);
180 from = ((loff_t)page) << this->page_shift;
181
182 while (totlen) {
183 len = min(totlen, (size_t)(1 << this->bbt_erase_shift));
184 if (marker_len) {
185 /*
186 * In case the BBT marker is not in the OOB area it
187 * will be just in the first page.
188 */
189 len -= marker_len;
190 from += marker_len;
191 marker_len = 0;
192 }
193 res = mtd_read(mtd, from, len, &retlen, buf);
194 if (res < 0) {
195 if (mtd_is_eccerr(res)) {
196 pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
197 from & ~mtd->writesize);
198 return res;
199 } else if (mtd_is_bitflip(res)) {
200 pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
201 from & ~mtd->writesize);
202 ret = res;
203 } else {
204 pr_info("nand_bbt: error reading BBT\n");
205 return res;
206 }
207 }
208
209 /* Analyse data */
210 for (i = 0; i < len; i++) {
211 uint8_t dat = buf[i];
212 for (j = 0; j < 8; j += bits, act++) {
213 uint8_t tmp = (dat >> j) & msk;
214 if (tmp == msk)
215 continue;
216 if (reserved_block_code && (tmp == reserved_block_code)) {
217 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
218 (loff_t)(offs + act) <<
219 this->bbt_erase_shift);
220 bbt_mark_entry(this, offs + act,
221 BBT_BLOCK_RESERVED);
222 mtd->ecc_stats.bbtblocks++;
223 continue;
224 }
225 /*
226 * Leave it for now, if it's matured we can
227 * move this message to pr_debug.
228 */
229 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
230 (loff_t)(offs + act) <<
231 this->bbt_erase_shift);
232 /* Factory marked bad or worn out? */
233 if (tmp == 0)
234 bbt_mark_entry(this, offs + act,
235 BBT_BLOCK_FACTORY_BAD);
236 else
237 bbt_mark_entry(this, offs + act,
238 BBT_BLOCK_WORN);
239 mtd->ecc_stats.badblocks++;
240 }
241 }
242 totlen -= len;
243 from += len;
244 }
245 return ret;
246 }
247
248 /**
249 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
250 * @this: NAND chip object
251 * @buf: temporary buffer
252 * @td: descriptor for the bad block table
253 * @chip: read the table for a specific chip, -1 read all chips; applies only if
254 * NAND_BBT_PERCHIP option is set
255 *
256 * Read the bad block table for all chips starting at a given page. We assume
257 * that the bbt bits are in consecutive order.
258 */
read_abs_bbt(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * td,int chip)259 static int read_abs_bbt(struct nand_chip *this, uint8_t *buf,
260 struct nand_bbt_descr *td, int chip)
261 {
262 struct mtd_info *mtd = nand_to_mtd(this);
263 u64 targetsize = nanddev_target_size(&this->base);
264 int res = 0, i;
265
266 if (td->options & NAND_BBT_PERCHIP) {
267 int offs = 0;
268 for (i = 0; i < nanddev_ntargets(&this->base); i++) {
269 if (chip == -1 || chip == i)
270 res = read_bbt(this, buf, td->pages[i],
271 targetsize >> this->bbt_erase_shift,
272 td, offs);
273 if (res)
274 return res;
275 offs += targetsize >> this->bbt_erase_shift;
276 }
277 } else {
278 res = read_bbt(this, buf, td->pages[0],
279 mtd->size >> this->bbt_erase_shift, td, 0);
280 if (res)
281 return res;
282 }
283 return 0;
284 }
285
286 /* BBT marker is in the first page, no OOB */
scan_read_data(struct nand_chip * this,uint8_t * buf,loff_t offs,struct nand_bbt_descr * td)287 static int scan_read_data(struct nand_chip *this, uint8_t *buf, loff_t offs,
288 struct nand_bbt_descr *td)
289 {
290 struct mtd_info *mtd = nand_to_mtd(this);
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 * @this: NAND chip object
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 nand_chip * this,uint8_t * buf,loff_t offs,size_t len)312 static int scan_read_oob(struct nand_chip *this, uint8_t *buf, loff_t offs,
313 size_t len)
314 {
315 struct mtd_info *mtd = nand_to_mtd(this);
316 struct mtd_oob_ops ops = { };
317 int res, ret = 0;
318
319 ops.mode = MTD_OPS_PLACE_OOB;
320 ops.ooboffs = 0;
321 ops.ooblen = mtd->oobsize;
322
323 while (len > 0) {
324 ops.datbuf = buf;
325 ops.len = min(len, (size_t)mtd->writesize);
326 ops.oobbuf = buf + ops.len;
327
328 res = mtd_read_oob(mtd, offs, &ops);
329 if (res) {
330 if (!mtd_is_bitflip_or_eccerr(res))
331 return res;
332 else if (mtd_is_eccerr(res) || !ret)
333 ret = res;
334 }
335
336 buf += mtd->oobsize + mtd->writesize;
337 len -= mtd->writesize;
338 offs += mtd->writesize;
339 }
340 return ret;
341 }
342
scan_read(struct nand_chip * this,uint8_t * buf,loff_t offs,size_t len,struct nand_bbt_descr * td)343 static int scan_read(struct nand_chip *this, uint8_t *buf, loff_t offs,
344 size_t len, struct nand_bbt_descr *td)
345 {
346 if (td->options & NAND_BBT_NO_OOB)
347 return scan_read_data(this, buf, offs, td);
348 else
349 return scan_read_oob(this, buf, offs, len);
350 }
351
352 /* Scan write data with oob to flash */
scan_write_bbt(struct nand_chip * this,loff_t offs,size_t len,uint8_t * buf,uint8_t * oob)353 static int scan_write_bbt(struct nand_chip *this, loff_t offs, size_t len,
354 uint8_t *buf, uint8_t *oob)
355 {
356 struct mtd_info *mtd = nand_to_mtd(this);
357 struct mtd_oob_ops ops = { };
358
359 ops.mode = MTD_OPS_PLACE_OOB;
360 ops.ooboffs = 0;
361 ops.ooblen = mtd->oobsize;
362 ops.datbuf = buf;
363 ops.oobbuf = oob;
364 ops.len = len;
365
366 return mtd_write_oob(mtd, offs, &ops);
367 }
368
bbt_get_ver_offs(struct nand_chip * this,struct nand_bbt_descr * td)369 static u32 bbt_get_ver_offs(struct nand_chip *this, struct nand_bbt_descr *td)
370 {
371 struct mtd_info *mtd = nand_to_mtd(this);
372 u32 ver_offs = td->veroffs;
373
374 if (!(td->options & NAND_BBT_NO_OOB))
375 ver_offs += mtd->writesize;
376 return ver_offs;
377 }
378
379 /**
380 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
381 * @this: NAND chip object
382 * @buf: temporary buffer
383 * @td: descriptor for the bad block table
384 * @md: descriptor for the bad block table mirror
385 *
386 * Read the bad block table(s) for all chips starting at a given page. We
387 * assume that the bbt bits are in consecutive order.
388 */
read_abs_bbts(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * td,struct nand_bbt_descr * md)389 static void read_abs_bbts(struct nand_chip *this, uint8_t *buf,
390 struct nand_bbt_descr *td, struct nand_bbt_descr *md)
391 {
392 struct mtd_info *mtd = nand_to_mtd(this);
393
394 /* Read the primary version, if available */
395 if (td->options & NAND_BBT_VERSION) {
396 scan_read(this, buf, (loff_t)td->pages[0] << this->page_shift,
397 mtd->writesize, td);
398 td->version[0] = buf[bbt_get_ver_offs(this, td)];
399 pr_info("Bad block table at page %d, version 0x%02X\n",
400 td->pages[0], td->version[0]);
401 }
402
403 /* Read the mirror version, if available */
404 if (md && (md->options & NAND_BBT_VERSION)) {
405 scan_read(this, buf, (loff_t)md->pages[0] << this->page_shift,
406 mtd->writesize, md);
407 md->version[0] = buf[bbt_get_ver_offs(this, md)];
408 pr_info("Bad block table at page %d, version 0x%02X\n",
409 md->pages[0], md->version[0]);
410 }
411 }
412
413 /* Scan a given block partially */
scan_block_fast(struct nand_chip * this,struct nand_bbt_descr * bd,loff_t offs,uint8_t * buf)414 static int scan_block_fast(struct nand_chip *this, struct nand_bbt_descr *bd,
415 loff_t offs, uint8_t *buf)
416 {
417 struct mtd_info *mtd = nand_to_mtd(this);
418
419 struct mtd_oob_ops ops = { };
420 int ret, page_offset;
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 page_offset = nand_bbm_get_next_page(this, 0);
429
430 while (page_offset >= 0) {
431 /*
432 * Read the full oob until read_oob is fixed to handle single
433 * byte reads for 16 bit buswidth.
434 */
435 ret = mtd_read_oob(mtd, offs + (page_offset * mtd->writesize),
436 &ops);
437 /* Ignore ECC errors when checking for BBM */
438 if (ret && !mtd_is_bitflip_or_eccerr(ret))
439 return ret;
440
441 if (check_short_pattern(buf, bd))
442 return 1;
443
444 page_offset = nand_bbm_get_next_page(this, page_offset + 1);
445 }
446
447 return 0;
448 }
449
450 /* Check if a potential BBT block is marked as bad */
bbt_block_checkbad(struct nand_chip * this,struct nand_bbt_descr * td,loff_t offs,uint8_t * buf)451 static int bbt_block_checkbad(struct nand_chip *this, struct nand_bbt_descr *td,
452 loff_t offs, uint8_t *buf)
453 {
454 struct nand_bbt_descr *bd = this->badblock_pattern;
455
456 /*
457 * No need to check for a bad BBT block if the BBM area overlaps with
458 * the bad block table marker area in OOB since writing a BBM here
459 * invalidates the bad block table marker anyway.
460 */
461 if (!(td->options & NAND_BBT_NO_OOB) &&
462 td->offs >= bd->offs && td->offs < bd->offs + bd->len)
463 return 0;
464
465 /*
466 * There is no point in checking for a bad block marker if writing
467 * such marker is not supported
468 */
469 if (this->bbt_options & NAND_BBT_NO_OOB_BBM ||
470 this->options & NAND_NO_BBM_QUIRK)
471 return 0;
472
473 if (scan_block_fast(this, bd, offs, buf) > 0)
474 return 1;
475
476 return 0;
477 }
478
479 /**
480 * create_bbt - [GENERIC] Create a bad block table by scanning the device
481 * @this: NAND chip object
482 * @buf: temporary buffer
483 * @bd: descriptor for the good/bad block search pattern
484 * @chip: create the table for a specific chip, -1 read all chips; applies only
485 * if NAND_BBT_PERCHIP option is set
486 *
487 * Create a bad block table by scanning the device for the given good/bad block
488 * identify pattern.
489 */
create_bbt(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * bd,int chip)490 static int create_bbt(struct nand_chip *this, uint8_t *buf,
491 struct nand_bbt_descr *bd, int chip)
492 {
493 u64 targetsize = nanddev_target_size(&this->base);
494 struct mtd_info *mtd = nand_to_mtd(this);
495 int i, numblocks, startblock;
496 loff_t from;
497
498 pr_info("Scanning device for bad blocks\n");
499
500 if (chip == -1) {
501 numblocks = mtd->size >> this->bbt_erase_shift;
502 startblock = 0;
503 from = 0;
504 } else {
505 if (chip >= nanddev_ntargets(&this->base)) {
506 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
507 chip + 1, nanddev_ntargets(&this->base));
508 return -EINVAL;
509 }
510 numblocks = targetsize >> this->bbt_erase_shift;
511 startblock = chip * numblocks;
512 numblocks += startblock;
513 from = (loff_t)startblock << this->bbt_erase_shift;
514 }
515
516 for (i = startblock; i < numblocks; i++) {
517 int ret;
518
519 BUG_ON(bd->options & NAND_BBT_NO_OOB);
520
521 ret = scan_block_fast(this, bd, from, buf);
522 if (ret < 0)
523 return ret;
524
525 if (ret) {
526 bbt_mark_entry(this, i, BBT_BLOCK_FACTORY_BAD);
527 pr_warn("Bad eraseblock %d at 0x%012llx\n",
528 i, (unsigned long long)from);
529 mtd->ecc_stats.badblocks++;
530 }
531
532 from += (1 << this->bbt_erase_shift);
533 }
534 return 0;
535 }
536
537 /**
538 * search_bbt - [GENERIC] scan the device for a specific bad block table
539 * @this: NAND chip object
540 * @buf: temporary buffer
541 * @td: descriptor for the bad block table
542 *
543 * Read the bad block table by searching for a given ident pattern. Search is
544 * preformed either from the beginning up or from the end of the device
545 * downwards. The search starts always at the start of a block. If the option
546 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
547 * the bad block information of this chip. This is necessary to provide support
548 * for certain DOC devices.
549 *
550 * The bbt ident pattern resides in the oob area of the first page in a block.
551 */
search_bbt(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * td)552 static int search_bbt(struct nand_chip *this, uint8_t *buf,
553 struct nand_bbt_descr *td)
554 {
555 u64 targetsize = nanddev_target_size(&this->base);
556 struct mtd_info *mtd = nand_to_mtd(this);
557 int i, chips;
558 int startblock, block, dir;
559 int scanlen = mtd->writesize + mtd->oobsize;
560 int bbtblocks;
561 int blocktopage = this->bbt_erase_shift - this->page_shift;
562
563 /* Search direction top -> down? */
564 if (td->options & NAND_BBT_LASTBLOCK) {
565 startblock = (mtd->size >> this->bbt_erase_shift) - 1;
566 dir = -1;
567 } else {
568 startblock = 0;
569 dir = 1;
570 }
571
572 /* Do we have a bbt per chip? */
573 if (td->options & NAND_BBT_PERCHIP) {
574 chips = nanddev_ntargets(&this->base);
575 bbtblocks = targetsize >> this->bbt_erase_shift;
576 startblock &= bbtblocks - 1;
577 } else {
578 chips = 1;
579 bbtblocks = mtd->size >> this->bbt_erase_shift;
580 }
581
582 for (i = 0; i < chips; i++) {
583 /* Reset version information */
584 td->version[i] = 0;
585 td->pages[i] = -1;
586 /* Scan the maximum number of blocks */
587 for (block = 0; block < td->maxblocks; block++) {
588
589 int actblock = startblock + dir * block;
590 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
591
592 /* Check if block is marked bad */
593 if (bbt_block_checkbad(this, td, offs, buf))
594 continue;
595
596 /* Read first page */
597 scan_read(this, buf, offs, mtd->writesize, td);
598 if (!check_pattern(buf, scanlen, mtd->writesize, td)) {
599 td->pages[i] = actblock << blocktopage;
600 if (td->options & NAND_BBT_VERSION) {
601 offs = bbt_get_ver_offs(this, td);
602 td->version[i] = buf[offs];
603 }
604 break;
605 }
606 }
607 startblock += targetsize >> this->bbt_erase_shift;
608 }
609 /* Check, if we found a bbt for each requested chip */
610 for (i = 0; i < chips; i++) {
611 if (td->pages[i] == -1)
612 pr_warn("Bad block table not found for chip %d\n", i);
613 else
614 pr_info("Bad block table found at page %d, version 0x%02X\n",
615 td->pages[i], td->version[i]);
616 }
617 return 0;
618 }
619
620 /**
621 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
622 * @this: NAND chip object
623 * @buf: temporary buffer
624 * @td: descriptor for the bad block table
625 * @md: descriptor for the bad block table mirror
626 *
627 * Search and read the bad block table(s).
628 */
search_read_bbts(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * td,struct nand_bbt_descr * md)629 static void search_read_bbts(struct nand_chip *this, uint8_t *buf,
630 struct nand_bbt_descr *td,
631 struct nand_bbt_descr *md)
632 {
633 /* Search the primary table */
634 search_bbt(this, buf, td);
635
636 /* Search the mirror table */
637 if (md)
638 search_bbt(this, buf, md);
639 }
640
641 /**
642 * get_bbt_block - Get the first valid eraseblock suitable to store a BBT
643 * @this: the NAND device
644 * @td: the BBT description
645 * @md: the mirror BBT descriptor
646 * @chip: the CHIP selector
647 *
648 * This functions returns a positive block number pointing a valid eraseblock
649 * suitable to store a BBT (i.e. in the range reserved for BBT), or -ENOSPC if
650 * all blocks are already used of marked bad. If td->pages[chip] was already
651 * pointing to a valid block we re-use it, otherwise we search for the next
652 * valid one.
653 */
get_bbt_block(struct nand_chip * this,struct nand_bbt_descr * td,struct nand_bbt_descr * md,int chip)654 static int get_bbt_block(struct nand_chip *this, struct nand_bbt_descr *td,
655 struct nand_bbt_descr *md, int chip)
656 {
657 u64 targetsize = nanddev_target_size(&this->base);
658 int startblock, dir, page, numblocks, i;
659
660 /*
661 * There was already a version of the table, reuse the page. This
662 * applies for absolute placement too, as we have the page number in
663 * td->pages.
664 */
665 if (td->pages[chip] != -1)
666 return td->pages[chip] >>
667 (this->bbt_erase_shift - this->page_shift);
668
669 numblocks = (int)(targetsize >> this->bbt_erase_shift);
670 if (!(td->options & NAND_BBT_PERCHIP))
671 numblocks *= nanddev_ntargets(&this->base);
672
673 /*
674 * Automatic placement of the bad block table. Search direction
675 * top -> down?
676 */
677 if (td->options & NAND_BBT_LASTBLOCK) {
678 startblock = numblocks * (chip + 1) - 1;
679 dir = -1;
680 } else {
681 startblock = chip * numblocks;
682 dir = 1;
683 }
684
685 for (i = 0; i < td->maxblocks; i++) {
686 int block = startblock + dir * i;
687
688 /* Check, if the block is bad */
689 switch (bbt_get_entry(this, block)) {
690 case BBT_BLOCK_WORN:
691 case BBT_BLOCK_FACTORY_BAD:
692 continue;
693 }
694
695 page = block << (this->bbt_erase_shift - this->page_shift);
696
697 /* Check, if the block is used by the mirror table */
698 if (!md || md->pages[chip] != page)
699 return block;
700 }
701
702 return -ENOSPC;
703 }
704
705 /**
706 * mark_bbt_block_bad - Mark one of the block reserved for BBT bad
707 * @this: the NAND device
708 * @td: the BBT description
709 * @chip: the CHIP selector
710 * @block: the BBT block to mark
711 *
712 * Blocks reserved for BBT can become bad. This functions is an helper to mark
713 * such blocks as bad. It takes care of updating the in-memory BBT, marking the
714 * block as bad using a bad block marker and invalidating the associated
715 * td->pages[] entry.
716 */
mark_bbt_block_bad(struct nand_chip * this,struct nand_bbt_descr * td,int chip,int block)717 static void mark_bbt_block_bad(struct nand_chip *this,
718 struct nand_bbt_descr *td,
719 int chip, int block)
720 {
721 loff_t to;
722 int res;
723
724 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
725
726 to = (loff_t)block << this->bbt_erase_shift;
727 res = nand_markbad_bbm(this, to);
728 if (res)
729 pr_warn("nand_bbt: error %d while marking block %d bad\n",
730 res, block);
731
732 td->pages[chip] = -1;
733 }
734
735 /**
736 * write_bbt - [GENERIC] (Re)write the bad block table
737 * @this: NAND chip object
738 * @buf: temporary buffer
739 * @td: descriptor for the bad block table
740 * @md: descriptor for the bad block table mirror
741 * @chipsel: selector for a specific chip, -1 for all
742 *
743 * (Re)write the bad block table.
744 */
write_bbt(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * td,struct nand_bbt_descr * md,int chipsel)745 static int write_bbt(struct nand_chip *this, uint8_t *buf,
746 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
747 int chipsel)
748 {
749 u64 targetsize = nanddev_target_size(&this->base);
750 struct mtd_info *mtd = nand_to_mtd(this);
751 struct erase_info einfo;
752 int i, res, chip = 0;
753 int bits, page, offs, numblocks, sft, sftmsk;
754 int nrchips, pageoffs, ooboffs;
755 uint8_t msk[4];
756 uint8_t rcode = td->reserved_block_code;
757 size_t retlen, len = 0;
758 loff_t to;
759 struct mtd_oob_ops ops = { };
760
761 ops.ooblen = mtd->oobsize;
762 ops.ooboffs = 0;
763 ops.datbuf = NULL;
764 ops.mode = MTD_OPS_PLACE_OOB;
765
766 if (!rcode)
767 rcode = 0xff;
768 /* Write bad block table per chip rather than per device? */
769 if (td->options & NAND_BBT_PERCHIP) {
770 numblocks = (int)(targetsize >> this->bbt_erase_shift);
771 /* Full device write or specific chip? */
772 if (chipsel == -1) {
773 nrchips = nanddev_ntargets(&this->base);
774 } else {
775 nrchips = chipsel + 1;
776 chip = chipsel;
777 }
778 } else {
779 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
780 nrchips = 1;
781 }
782
783 /* Loop through the chips */
784 while (chip < nrchips) {
785 int block;
786
787 block = get_bbt_block(this, td, md, chip);
788 if (block < 0) {
789 pr_err("No space left to write bad block table\n");
790 res = block;
791 goto outerr;
792 }
793
794 /*
795 * get_bbt_block() returns a block number, shift the value to
796 * get a page number.
797 */
798 page = block << (this->bbt_erase_shift - this->page_shift);
799
800 /* Set up shift count and masks for the flash table */
801 bits = td->options & NAND_BBT_NRBITS_MSK;
802 msk[2] = ~rcode;
803 switch (bits) {
804 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
805 msk[3] = 0x01;
806 break;
807 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
808 msk[3] = 0x03;
809 break;
810 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
811 msk[3] = 0x0f;
812 break;
813 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
814 msk[3] = 0xff;
815 break;
816 default: return -EINVAL;
817 }
818
819 to = ((loff_t)page) << this->page_shift;
820
821 /* Must we save the block contents? */
822 if (td->options & NAND_BBT_SAVECONTENT) {
823 /* Make it block aligned */
824 to &= ~(((loff_t)1 << this->bbt_erase_shift) - 1);
825 len = 1 << this->bbt_erase_shift;
826 res = mtd_read(mtd, to, len, &retlen, buf);
827 if (res < 0) {
828 if (retlen != len) {
829 pr_info("nand_bbt: error reading block for writing the bad block table\n");
830 return res;
831 }
832 pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
833 }
834 /* Read oob data */
835 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
836 ops.oobbuf = &buf[len];
837 res = mtd_read_oob(mtd, to + mtd->writesize, &ops);
838 if (res < 0 || ops.oobretlen != ops.ooblen)
839 goto outerr;
840
841 /* Calc the byte offset in the buffer */
842 pageoffs = page - (int)(to >> this->page_shift);
843 offs = pageoffs << this->page_shift;
844 /* Preset the bbt area with 0xff */
845 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
846 ooboffs = len + (pageoffs * mtd->oobsize);
847
848 } else if (td->options & NAND_BBT_NO_OOB) {
849 ooboffs = 0;
850 offs = td->len;
851 /* The version byte */
852 if (td->options & NAND_BBT_VERSION)
853 offs++;
854 /* Calc length */
855 len = (size_t)(numblocks >> sft);
856 len += offs;
857 /* Make it page aligned! */
858 len = ALIGN(len, mtd->writesize);
859 /* Preset the buffer with 0xff */
860 memset(buf, 0xff, len);
861 /* Pattern is located at the begin of first page */
862 memcpy(buf, td->pattern, td->len);
863 } else {
864 /* Calc length */
865 len = (size_t)(numblocks >> sft);
866 /* Make it page aligned! */
867 len = ALIGN(len, mtd->writesize);
868 /* Preset the buffer with 0xff */
869 memset(buf, 0xff, len +
870 (len >> this->page_shift)* mtd->oobsize);
871 offs = 0;
872 ooboffs = len;
873 /* Pattern is located in oob area of first page */
874 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
875 }
876
877 if (td->options & NAND_BBT_VERSION)
878 buf[ooboffs + td->veroffs] = td->version[chip];
879
880 /* Walk through the memory table */
881 for (i = 0; i < numblocks; i++) {
882 uint8_t dat;
883 int sftcnt = (i << (3 - sft)) & sftmsk;
884 dat = bbt_get_entry(this, chip * numblocks + i);
885 /* Do not store the reserved bbt blocks! */
886 buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
887 }
888
889 memset(&einfo, 0, sizeof(einfo));
890 einfo.addr = to;
891 einfo.len = 1 << this->bbt_erase_shift;
892 res = nand_erase_nand(this, &einfo, 1);
893 if (res < 0) {
894 pr_warn("nand_bbt: error while erasing BBT block %d\n",
895 res);
896 mark_bbt_block_bad(this, td, chip, block);
897 continue;
898 }
899
900 res = scan_write_bbt(this, to, len, buf,
901 td->options & NAND_BBT_NO_OOB ?
902 NULL : &buf[len]);
903 if (res < 0) {
904 pr_warn("nand_bbt: error while writing BBT block %d\n",
905 res);
906 mark_bbt_block_bad(this, td, chip, block);
907 continue;
908 }
909
910 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
911 (unsigned long long)to, td->version[chip]);
912
913 /* Mark it as used */
914 td->pages[chip++] = page;
915 }
916 return 0;
917
918 outerr:
919 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
920 return res;
921 }
922
923 /**
924 * nand_memory_bbt - [GENERIC] create a memory based bad block table
925 * @this: NAND chip object
926 * @bd: descriptor for the good/bad block search pattern
927 *
928 * The function creates a memory based bbt by scanning the device for
929 * manufacturer / software marked good / bad blocks.
930 */
nand_memory_bbt(struct nand_chip * this,struct nand_bbt_descr * bd)931 static inline int nand_memory_bbt(struct nand_chip *this,
932 struct nand_bbt_descr *bd)
933 {
934 u8 *pagebuf = nand_get_data_buf(this);
935
936 return create_bbt(this, pagebuf, bd, -1);
937 }
938
939 /**
940 * check_create - [GENERIC] create and write bbt(s) if necessary
941 * @this: the NAND device
942 * @buf: temporary buffer
943 * @bd: descriptor for the good/bad block search pattern
944 *
945 * The function checks the results of the previous call to read_bbt and creates
946 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
947 * for the chip/device. Update is necessary if one of the tables is missing or
948 * the version nr. of one table is less than the other.
949 */
check_create(struct nand_chip * this,uint8_t * buf,struct nand_bbt_descr * bd)950 static int check_create(struct nand_chip *this, uint8_t *buf,
951 struct nand_bbt_descr *bd)
952 {
953 int i, chips, writeops, create, chipsel, res, res2;
954 struct nand_bbt_descr *td = this->bbt_td;
955 struct nand_bbt_descr *md = this->bbt_md;
956 struct nand_bbt_descr *rd, *rd2;
957
958 /* Do we have a bbt per chip? */
959 if (td->options & NAND_BBT_PERCHIP)
960 chips = nanddev_ntargets(&this->base);
961 else
962 chips = 1;
963
964 for (i = 0; i < chips; i++) {
965 writeops = 0;
966 create = 0;
967 rd = NULL;
968 rd2 = NULL;
969 res = res2 = 0;
970 /* Per chip or per device? */
971 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
972 /* Mirrored table available? */
973 if (md) {
974 if (td->pages[i] == -1 && md->pages[i] == -1) {
975 create = 1;
976 writeops = 0x03;
977 } else if (td->pages[i] == -1) {
978 rd = md;
979 writeops = 0x01;
980 } else if (md->pages[i] == -1) {
981 rd = td;
982 writeops = 0x02;
983 } else if (td->version[i] == md->version[i]) {
984 rd = td;
985 if (!(td->options & NAND_BBT_VERSION))
986 rd2 = md;
987 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
988 rd = td;
989 writeops = 0x02;
990 } else {
991 rd = md;
992 writeops = 0x01;
993 }
994 } else {
995 if (td->pages[i] == -1) {
996 create = 1;
997 writeops = 0x01;
998 } else {
999 rd = td;
1000 }
1001 }
1002
1003 if (create) {
1004 /* Create the bad block table by scanning the device? */
1005 if (!(td->options & NAND_BBT_CREATE))
1006 continue;
1007
1008 /* Create the table in memory by scanning the chip(s) */
1009 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
1010 create_bbt(this, buf, bd, chipsel);
1011
1012 td->version[i] = 1;
1013 if (md)
1014 md->version[i] = 1;
1015 }
1016
1017 /* Read back first? */
1018 if (rd) {
1019 res = read_abs_bbt(this, buf, rd, chipsel);
1020 if (mtd_is_eccerr(res)) {
1021 /* Mark table as invalid */
1022 rd->pages[i] = -1;
1023 rd->version[i] = 0;
1024 i--;
1025 continue;
1026 }
1027 }
1028 /* If they weren't versioned, read both */
1029 if (rd2) {
1030 res2 = read_abs_bbt(this, buf, rd2, chipsel);
1031 if (mtd_is_eccerr(res2)) {
1032 /* Mark table as invalid */
1033 rd2->pages[i] = -1;
1034 rd2->version[i] = 0;
1035 i--;
1036 continue;
1037 }
1038 }
1039
1040 /* Scrub the flash table(s)? */
1041 if (mtd_is_bitflip(res) || mtd_is_bitflip(res2))
1042 writeops = 0x03;
1043
1044 /* Update version numbers before writing */
1045 if (md) {
1046 td->version[i] = max(td->version[i], md->version[i]);
1047 md->version[i] = td->version[i];
1048 }
1049
1050 /* Write the bad block table to the device? */
1051 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1052 res = write_bbt(this, buf, td, md, chipsel);
1053 if (res < 0)
1054 return res;
1055 }
1056
1057 /* Write the mirror bad block table to the device? */
1058 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1059 res = write_bbt(this, buf, md, td, chipsel);
1060 if (res < 0)
1061 return res;
1062 }
1063 }
1064 return 0;
1065 }
1066
1067 /**
1068 * nand_update_bbt - update bad block table(s)
1069 * @this: the NAND device
1070 * @offs: the offset of the newly marked block
1071 *
1072 * The function updates the bad block table(s).
1073 */
nand_update_bbt(struct nand_chip * this,loff_t offs)1074 static int nand_update_bbt(struct nand_chip *this, loff_t offs)
1075 {
1076 struct mtd_info *mtd = nand_to_mtd(this);
1077 int len, res = 0;
1078 int chip, chipsel;
1079 uint8_t *buf;
1080 struct nand_bbt_descr *td = this->bbt_td;
1081 struct nand_bbt_descr *md = this->bbt_md;
1082
1083 if (!this->bbt || !td)
1084 return -EINVAL;
1085
1086 /* Allocate a temporary buffer for one eraseblock incl. oob */
1087 len = (1 << this->bbt_erase_shift);
1088 len += (len >> this->page_shift) * mtd->oobsize;
1089 buf = kmalloc(len, GFP_KERNEL);
1090 if (!buf)
1091 return -ENOMEM;
1092
1093 /* Do we have a bbt per chip? */
1094 if (td->options & NAND_BBT_PERCHIP) {
1095 chip = (int)(offs >> this->chip_shift);
1096 chipsel = chip;
1097 } else {
1098 chip = 0;
1099 chipsel = -1;
1100 }
1101
1102 td->version[chip]++;
1103 if (md)
1104 md->version[chip]++;
1105
1106 /* Write the bad block table to the device? */
1107 if (td->options & NAND_BBT_WRITE) {
1108 res = write_bbt(this, buf, td, md, chipsel);
1109 if (res < 0)
1110 goto out;
1111 }
1112 /* Write the mirror bad block table to the device? */
1113 if (md && (md->options & NAND_BBT_WRITE)) {
1114 res = write_bbt(this, buf, md, td, chipsel);
1115 }
1116
1117 out:
1118 kfree(buf);
1119 return res;
1120 }
1121
1122 /**
1123 * mark_bbt_region - [GENERIC] mark the bad block table regions
1124 * @this: the NAND device
1125 * @td: bad block table descriptor
1126 *
1127 * The bad block table regions are marked as "bad" to prevent accidental
1128 * erasures / writes. The regions are identified by the mark 0x02.
1129 */
mark_bbt_region(struct nand_chip * this,struct nand_bbt_descr * td)1130 static void mark_bbt_region(struct nand_chip *this, struct nand_bbt_descr *td)
1131 {
1132 u64 targetsize = nanddev_target_size(&this->base);
1133 struct mtd_info *mtd = nand_to_mtd(this);
1134 int i, j, chips, block, nrblocks, update;
1135 uint8_t oldval;
1136
1137 /* Do we have a bbt per chip? */
1138 if (td->options & NAND_BBT_PERCHIP) {
1139 chips = nanddev_ntargets(&this->base);
1140 nrblocks = (int)(targetsize >> this->bbt_erase_shift);
1141 } else {
1142 chips = 1;
1143 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1144 }
1145
1146 for (i = 0; i < chips; i++) {
1147 if ((td->options & NAND_BBT_ABSPAGE) ||
1148 !(td->options & NAND_BBT_WRITE)) {
1149 if (td->pages[i] == -1)
1150 continue;
1151 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1152 oldval = bbt_get_entry(this, block);
1153 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1154 if ((oldval != BBT_BLOCK_RESERVED) &&
1155 td->reserved_block_code)
1156 nand_update_bbt(this, (loff_t)block <<
1157 this->bbt_erase_shift);
1158 continue;
1159 }
1160 update = 0;
1161 if (td->options & NAND_BBT_LASTBLOCK)
1162 block = ((i + 1) * nrblocks) - td->maxblocks;
1163 else
1164 block = i * nrblocks;
1165 for (j = 0; j < td->maxblocks; j++) {
1166 oldval = bbt_get_entry(this, block);
1167 bbt_mark_entry(this, block, BBT_BLOCK_RESERVED);
1168 if (oldval != BBT_BLOCK_RESERVED)
1169 update = 1;
1170 block++;
1171 }
1172 /*
1173 * If we want reserved blocks to be recorded to flash, and some
1174 * new ones have been marked, then we need to update the stored
1175 * bbts. This should only happen once.
1176 */
1177 if (update && td->reserved_block_code)
1178 nand_update_bbt(this, (loff_t)(block - 1) <<
1179 this->bbt_erase_shift);
1180 }
1181 }
1182
1183 /**
1184 * verify_bbt_descr - verify the bad block description
1185 * @this: the NAND device
1186 * @bd: the table to verify
1187 *
1188 * This functions performs a few sanity checks on the bad block description
1189 * table.
1190 */
verify_bbt_descr(struct nand_chip * this,struct nand_bbt_descr * bd)1191 static void verify_bbt_descr(struct nand_chip *this, struct nand_bbt_descr *bd)
1192 {
1193 u64 targetsize = nanddev_target_size(&this->base);
1194 struct mtd_info *mtd = nand_to_mtd(this);
1195 u32 pattern_len;
1196 u32 bits;
1197 u32 table_size;
1198
1199 if (!bd)
1200 return;
1201
1202 pattern_len = bd->len;
1203 bits = bd->options & NAND_BBT_NRBITS_MSK;
1204
1205 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1206 !(this->bbt_options & NAND_BBT_USE_FLASH));
1207 BUG_ON(!bits);
1208
1209 if (bd->options & NAND_BBT_VERSION)
1210 pattern_len++;
1211
1212 if (bd->options & NAND_BBT_NO_OOB) {
1213 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1214 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1215 BUG_ON(bd->offs);
1216 if (bd->options & NAND_BBT_VERSION)
1217 BUG_ON(bd->veroffs != bd->len);
1218 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1219 }
1220
1221 if (bd->options & NAND_BBT_PERCHIP)
1222 table_size = targetsize >> this->bbt_erase_shift;
1223 else
1224 table_size = mtd->size >> this->bbt_erase_shift;
1225 table_size >>= 3;
1226 table_size *= bits;
1227 if (bd->options & NAND_BBT_NO_OOB)
1228 table_size += pattern_len;
1229 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1230 }
1231
1232 /**
1233 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1234 * @this: the NAND device
1235 * @bd: descriptor for the good/bad block search pattern
1236 *
1237 * The function checks, if a bad block table(s) is/are already available. If
1238 * not it scans the device for manufacturer marked good / bad blocks and writes
1239 * the bad block table(s) to the selected place.
1240 *
1241 * The bad block table memory is allocated here. It must be freed by calling
1242 * the nand_free_bbt function.
1243 */
nand_scan_bbt(struct nand_chip * this,struct nand_bbt_descr * bd)1244 static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
1245 {
1246 struct mtd_info *mtd = nand_to_mtd(this);
1247 int len, res;
1248 uint8_t *buf;
1249 struct nand_bbt_descr *td = this->bbt_td;
1250 struct nand_bbt_descr *md = this->bbt_md;
1251
1252 len = (mtd->size >> (this->bbt_erase_shift + 2)) ? : 1;
1253 /*
1254 * Allocate memory (2bit per block) and clear the memory bad block
1255 * table.
1256 */
1257 this->bbt = kzalloc(len, GFP_KERNEL);
1258 if (!this->bbt)
1259 return -ENOMEM;
1260
1261 /*
1262 * If no primary table descriptor is given, scan the device to build a
1263 * memory based bad block table.
1264 */
1265 if (!td) {
1266 if ((res = nand_memory_bbt(this, bd))) {
1267 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1268 goto err_free_bbt;
1269 }
1270 return 0;
1271 }
1272 verify_bbt_descr(this, td);
1273 verify_bbt_descr(this, md);
1274
1275 /* Allocate a temporary buffer for one eraseblock incl. oob */
1276 len = (1 << this->bbt_erase_shift);
1277 len += (len >> this->page_shift) * mtd->oobsize;
1278 buf = vmalloc(len);
1279 if (!buf) {
1280 res = -ENOMEM;
1281 goto err_free_bbt;
1282 }
1283
1284 /* Is the bbt at a given page? */
1285 if (td->options & NAND_BBT_ABSPAGE) {
1286 read_abs_bbts(this, buf, td, md);
1287 } else {
1288 /* Search the bad block table using a pattern in oob */
1289 search_read_bbts(this, buf, td, md);
1290 }
1291
1292 res = check_create(this, buf, bd);
1293 if (res)
1294 goto err_free_buf;
1295
1296 /* Prevent the bbt regions from erasing / writing */
1297 mark_bbt_region(this, td);
1298 if (md)
1299 mark_bbt_region(this, md);
1300
1301 vfree(buf);
1302 return 0;
1303
1304 err_free_buf:
1305 vfree(buf);
1306 err_free_bbt:
1307 kfree(this->bbt);
1308 this->bbt = NULL;
1309 return res;
1310 }
1311
1312 /*
1313 * Define some generic bad / good block scan pattern which are used
1314 * while scanning a device for factory marked good / bad blocks.
1315 */
1316 static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1317
1318 /* Generic flash bbt descriptors */
1319 static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1320 static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1321
1322 static struct nand_bbt_descr bbt_main_descr = {
1323 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1324 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1325 .offs = 8,
1326 .len = 4,
1327 .veroffs = 12,
1328 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1329 .pattern = bbt_pattern
1330 };
1331
1332 static struct nand_bbt_descr bbt_mirror_descr = {
1333 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1334 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1335 .offs = 8,
1336 .len = 4,
1337 .veroffs = 12,
1338 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1339 .pattern = mirror_pattern
1340 };
1341
1342 static struct nand_bbt_descr bbt_main_no_oob_descr = {
1343 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1344 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1345 | NAND_BBT_NO_OOB,
1346 .len = 4,
1347 .veroffs = 4,
1348 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1349 .pattern = bbt_pattern
1350 };
1351
1352 static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1353 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1354 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1355 | NAND_BBT_NO_OOB,
1356 .len = 4,
1357 .veroffs = 4,
1358 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1359 .pattern = mirror_pattern
1360 };
1361
1362 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1363 /**
1364 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1365 * @this: NAND chip to create descriptor for
1366 *
1367 * This function allocates and initializes a nand_bbt_descr for BBM detection
1368 * based on the properties of @this. The new descriptor is stored in
1369 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1370 * passed to this function.
1371 */
nand_create_badblock_pattern(struct nand_chip * this)1372 static int nand_create_badblock_pattern(struct nand_chip *this)
1373 {
1374 struct nand_bbt_descr *bd;
1375 if (this->badblock_pattern) {
1376 pr_warn("Bad block pattern already allocated; not replacing\n");
1377 return -EINVAL;
1378 }
1379 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
1380 if (!bd)
1381 return -ENOMEM;
1382 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1383 bd->offs = this->badblockpos;
1384 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1385 bd->pattern = scan_ff_pattern;
1386 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1387 this->badblock_pattern = bd;
1388 return 0;
1389 }
1390
1391 /**
1392 * nand_create_bbt - [NAND Interface] Select a default bad block table for the device
1393 * @this: NAND chip object
1394 *
1395 * This function selects the default bad block table support for the device and
1396 * calls the nand_scan_bbt function.
1397 */
nand_create_bbt(struct nand_chip * this)1398 int nand_create_bbt(struct nand_chip *this)
1399 {
1400 int ret;
1401
1402 /* Is a flash based bad block table requested? */
1403 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1404 /* Use the default pattern descriptors */
1405 if (!this->bbt_td) {
1406 if (this->bbt_options & NAND_BBT_NO_OOB) {
1407 this->bbt_td = &bbt_main_no_oob_descr;
1408 this->bbt_md = &bbt_mirror_no_oob_descr;
1409 } else {
1410 this->bbt_td = &bbt_main_descr;
1411 this->bbt_md = &bbt_mirror_descr;
1412 }
1413 }
1414 } else {
1415 this->bbt_td = NULL;
1416 this->bbt_md = NULL;
1417 }
1418
1419 if (!this->badblock_pattern) {
1420 ret = nand_create_badblock_pattern(this);
1421 if (ret)
1422 return ret;
1423 }
1424
1425 return nand_scan_bbt(this, this->badblock_pattern);
1426 }
1427 EXPORT_SYMBOL(nand_create_bbt);
1428
1429 /**
1430 * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
1431 * @this: NAND chip object
1432 * @offs: offset in the device
1433 */
nand_isreserved_bbt(struct nand_chip * this,loff_t offs)1434 int nand_isreserved_bbt(struct nand_chip *this, loff_t offs)
1435 {
1436 int block;
1437
1438 block = (int)(offs >> this->bbt_erase_shift);
1439 return bbt_get_entry(this, block) == BBT_BLOCK_RESERVED;
1440 }
1441
1442 /**
1443 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1444 * @this: NAND chip object
1445 * @offs: offset in the device
1446 * @allowbbt: allow access to bad block table region
1447 */
nand_isbad_bbt(struct nand_chip * this,loff_t offs,int allowbbt)1448 int nand_isbad_bbt(struct nand_chip *this, loff_t offs, int allowbbt)
1449 {
1450 int block, res;
1451
1452 block = (int)(offs >> this->bbt_erase_shift);
1453 res = bbt_get_entry(this, block);
1454
1455 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1456 (unsigned int)offs, block, res);
1457
1458 if (mtd_check_expert_analysis_mode())
1459 return 0;
1460
1461 switch (res) {
1462 case BBT_BLOCK_GOOD:
1463 return 0;
1464 case BBT_BLOCK_WORN:
1465 return 1;
1466 case BBT_BLOCK_RESERVED:
1467 return allowbbt ? 0 : 1;
1468 }
1469 return 1;
1470 }
1471
1472 /**
1473 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1474 * @this: NAND chip object
1475 * @offs: offset of the bad block
1476 */
nand_markbad_bbt(struct nand_chip * this,loff_t offs)1477 int nand_markbad_bbt(struct nand_chip *this, loff_t offs)
1478 {
1479 int block, ret = 0;
1480
1481 block = (int)(offs >> this->bbt_erase_shift);
1482
1483 /* Mark bad block in memory */
1484 bbt_mark_entry(this, block, BBT_BLOCK_WORN);
1485
1486 /* Update flash-based bad block table */
1487 if (this->bbt_options & NAND_BBT_USE_FLASH)
1488 ret = nand_update_bbt(this, offs);
1489
1490 return ret;
1491 }
1492