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22 * If one of the BBTs is out of date or does not exist it is (re)created.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
76static 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
83static 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
90static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td)
91{
92 if (memcmp(p: buf, q: td->pattern, size: 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 */
107static 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(p: buf + paglen + td->offs, q: td->pattern, size: 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 */
128static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td)
129{
130 /* Compare the pattern */
131 if (memcmp(p: buf + td->offs, q: td->pattern, size: 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 */
142static 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 */
166static 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(chip: 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: &retlen, buf);
194 if (res < 0) {
195 if (mtd_is_eccerr(err: 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(err: 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(chip: this, block: 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(chip: this, block: offs + act,
235 BBT_BLOCK_FACTORY_BAD);
236 else
237 bbt_mark_entry(chip: this, block: 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 */
259static 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(chip: this);
263 u64 targetsize = nanddev_target_size(nand: &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(nand: &this->base); i++) {
269 if (chip == -1 || chip == i)
270 res = read_bbt(this, buf, page: td->pages[i],
271 num: 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, page: td->pages[0],
279 num: mtd->size >> this->bbt_erase_shift, td, offs: 0);
280 if (res)
281 return res;
282 }
283 return 0;
284}
285
286/* BBT marker is in the first page, no OOB */
287static 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(chip: 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, from: offs, len, retlen: &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 */
312static 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(chip: 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, from: offs, ops: &ops);
329 if (res) {
330 if (!mtd_is_bitflip_or_eccerr(err: res))
331 return res;
332 else if (mtd_is_eccerr(err: 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
343static 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 */
353static 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(chip: 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, to: offs, ops: &ops);
367}
368
369static u32 bbt_get_ver_offs(struct nand_chip *this, struct nand_bbt_descr *td)
370{
371 struct mtd_info *mtd = nand_to_mtd(chip: 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 */
389static 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(chip: this);
393
394 /* Read the primary version, if available */
395 if (td->options & NAND_BBT_VERSION) {
396 scan_read(this, buf, offs: (loff_t)td->pages[0] << this->page_shift,
397 len: 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, offs: (loff_t)md->pages[0] << this->page_shift,
406 len: mtd->writesize, td: md);
407 md->version[0] = buf[bbt_get_ver_offs(this, td: 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 */
414static 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(chip: 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(chip: this, page: 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, from: offs + (page_offset * mtd->writesize),
436 ops: &ops);
437 /* Ignore ECC errors when checking for BBM */
438 if (ret && !mtd_is_bitflip_or_eccerr(err: ret))
439 return ret;
440
441 if (check_short_pattern(buf, td: bd))
442 return 1;
443
444 page_offset = nand_bbm_get_next_page(chip: this, page: page_offset + 1);
445 }
446
447 return 0;
448}
449
450/* Check if a potential BBT block is marked as bad */
451static 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 */
490static 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(nand: &this->base);
494 struct mtd_info *mtd = nand_to_mtd(chip: 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(nand: &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, offs: from, buf);
522 if (ret < 0)
523 return ret;
524
525 if (ret) {
526 bbt_mark_entry(chip: this, block: 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 */
552static int search_bbt(struct nand_chip *this, uint8_t *buf,
553 struct nand_bbt_descr *td)
554{
555 u64 targetsize = nanddev_target_size(nand: &this->base);
556 struct mtd_info *mtd = nand_to_mtd(chip: 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(nand: &this->base);
575 bbtblocks = targetsize >> this->bbt_erase_shift;
576 startblock &= bbtblocks - 1;
577 } else {
578 chips = 1;
579 }
580
581 for (i = 0; i < chips; i++) {
582 /* Reset version information */
583 td->version[i] = 0;
584 td->pages[i] = -1;
585 /* Scan the maximum number of blocks */
586 for (block = 0; block < td->maxblocks; block++) {
587
588 int actblock = startblock + dir * block;
589 loff_t offs = (loff_t)actblock << this->bbt_erase_shift;
590
591 /* Check if block is marked bad */
592 if (bbt_block_checkbad(this, td, offs, buf))
593 continue;
594
595 /* Read first page */
596 scan_read(this, buf, offs, len: mtd->writesize, td);
597 if (!check_pattern(buf, len: scanlen, paglen: mtd->writesize, td)) {
598 td->pages[i] = actblock << blocktopage;
599 if (td->options & NAND_BBT_VERSION) {
600 offs = bbt_get_ver_offs(this, td);
601 td->version[i] = buf[offs];
602 }
603 break;
604 }
605 }
606 startblock += targetsize >> this->bbt_erase_shift;
607 }
608 /* Check, if we found a bbt for each requested chip */
609 for (i = 0; i < chips; i++) {
610 if (td->pages[i] == -1)
611 pr_warn("Bad block table not found for chip %d\n", i);
612 else
613 pr_info("Bad block table found at page %d, version 0x%02X\n",
614 td->pages[i], td->version[i]);
615 }
616 return 0;
617}
618
619/**
620 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
621 * @this: NAND chip object
622 * @buf: temporary buffer
623 * @td: descriptor for the bad block table
624 * @md: descriptor for the bad block table mirror
625 *
626 * Search and read the bad block table(s).
627 */
628static void search_read_bbts(struct nand_chip *this, uint8_t *buf,
629 struct nand_bbt_descr *td,
630 struct nand_bbt_descr *md)
631{
632 /* Search the primary table */
633 search_bbt(this, buf, td);
634
635 /* Search the mirror table */
636 if (md)
637 search_bbt(this, buf, td: md);
638}
639
640/**
641 * get_bbt_block - Get the first valid eraseblock suitable to store a BBT
642 * @this: the NAND device
643 * @td: the BBT description
644 * @md: the mirror BBT descriptor
645 * @chip: the CHIP selector
646 *
647 * This functions returns a positive block number pointing a valid eraseblock
648 * suitable to store a BBT (i.e. in the range reserved for BBT), or -ENOSPC if
649 * all blocks are already used of marked bad. If td->pages[chip] was already
650 * pointing to a valid block we re-use it, otherwise we search for the next
651 * valid one.
652 */
653static int get_bbt_block(struct nand_chip *this, struct nand_bbt_descr *td,
654 struct nand_bbt_descr *md, int chip)
655{
656 u64 targetsize = nanddev_target_size(nand: &this->base);
657 int startblock, dir, page, numblocks, i;
658
659 /*
660 * There was already a version of the table, reuse the page. This
661 * applies for absolute placement too, as we have the page number in
662 * td->pages.
663 */
664 if (td->pages[chip] != -1)
665 return td->pages[chip] >>
666 (this->bbt_erase_shift - this->page_shift);
667
668 numblocks = (int)(targetsize >> this->bbt_erase_shift);
669 if (!(td->options & NAND_BBT_PERCHIP))
670 numblocks *= nanddev_ntargets(nand: &this->base);
671
672 /*
673 * Automatic placement of the bad block table. Search direction
674 * top -> down?
675 */
676 if (td->options & NAND_BBT_LASTBLOCK) {
677 startblock = numblocks * (chip + 1) - 1;
678 dir = -1;
679 } else {
680 startblock = chip * numblocks;
681 dir = 1;
682 }
683
684 for (i = 0; i < td->maxblocks; i++) {
685 int block = startblock + dir * i;
686
687 /* Check, if the block is bad */
688 switch (bbt_get_entry(chip: this, block)) {
689 case BBT_BLOCK_WORN:
690 case BBT_BLOCK_FACTORY_BAD:
691 continue;
692 }
693
694 page = block << (this->bbt_erase_shift - this->page_shift);
695
696 /* Check, if the block is used by the mirror table */
697 if (!md || md->pages[chip] != page)
698 return block;
699 }
700
701 return -ENOSPC;
702}
703
704/**
705 * mark_bbt_block_bad - Mark one of the block reserved for BBT bad
706 * @this: the NAND device
707 * @td: the BBT description
708 * @chip: the CHIP selector
709 * @block: the BBT block to mark
710 *
711 * Blocks reserved for BBT can become bad. This functions is an helper to mark
712 * such blocks as bad. It takes care of updating the in-memory BBT, marking the
713 * block as bad using a bad block marker and invalidating the associated
714 * td->pages[] entry.
715 */
716static void mark_bbt_block_bad(struct nand_chip *this,
717 struct nand_bbt_descr *td,
718 int chip, int block)
719{
720 loff_t to;
721 int res;
722
723 bbt_mark_entry(chip: this, block, BBT_BLOCK_WORN);
724
725 to = (loff_t)block << this->bbt_erase_shift;
726 res = nand_markbad_bbm(chip: this, ofs: to);
727 if (res)
728 pr_warn("nand_bbt: error %d while marking block %d bad\n",
729 res, block);
730
731 td->pages[chip] = -1;
732}
733
734/**
735 * write_bbt - [GENERIC] (Re)write the bad block table
736 * @this: NAND chip object
737 * @buf: temporary buffer
738 * @td: descriptor for the bad block table
739 * @md: descriptor for the bad block table mirror
740 * @chipsel: selector for a specific chip, -1 for all
741 *
742 * (Re)write the bad block table.
743 */
744static int write_bbt(struct nand_chip *this, uint8_t *buf,
745 struct nand_bbt_descr *td, struct nand_bbt_descr *md,
746 int chipsel)
747{
748 u64 targetsize = nanddev_target_size(nand: &this->base);
749 struct mtd_info *mtd = nand_to_mtd(chip: this);
750 struct erase_info einfo;
751 int i, res, chip = 0;
752 int bits, page, offs, numblocks, sft, sftmsk;
753 int nrchips, pageoffs, ooboffs;
754 uint8_t msk[4];
755 uint8_t rcode = td->reserved_block_code;
756 size_t retlen, len = 0;
757 loff_t to;
758 struct mtd_oob_ops ops = { };
759
760 ops.ooblen = mtd->oobsize;
761 ops.ooboffs = 0;
762 ops.datbuf = NULL;
763 ops.mode = MTD_OPS_PLACE_OOB;
764
765 if (!rcode)
766 rcode = 0xff;
767 /* Write bad block table per chip rather than per device? */
768 if (td->options & NAND_BBT_PERCHIP) {
769 numblocks = (int)(targetsize >> this->bbt_erase_shift);
770 /* Full device write or specific chip? */
771 if (chipsel == -1) {
772 nrchips = nanddev_ntargets(nand: &this->base);
773 } else {
774 nrchips = chipsel + 1;
775 chip = chipsel;
776 }
777 } else {
778 numblocks = (int)(mtd->size >> this->bbt_erase_shift);
779 nrchips = 1;
780 }
781
782 /* Loop through the chips */
783 while (chip < nrchips) {
784 int block;
785
786 block = get_bbt_block(this, td, md, chip);
787 if (block < 0) {
788 pr_err("No space left to write bad block table\n");
789 res = block;
790 goto outerr;
791 }
792
793 /*
794 * get_bbt_block() returns a block number, shift the value to
795 * get a page number.
796 */
797 page = block << (this->bbt_erase_shift - this->page_shift);
798
799 /* Set up shift count and masks for the flash table */
800 bits = td->options & NAND_BBT_NRBITS_MSK;
801 msk[2] = ~rcode;
802 switch (bits) {
803 case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01;
804 msk[3] = 0x01;
805 break;
806 case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01;
807 msk[3] = 0x03;
808 break;
809 case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C;
810 msk[3] = 0x0f;
811 break;
812 case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F;
813 msk[3] = 0xff;
814 break;
815 default: return -EINVAL;
816 }
817
818 to = ((loff_t)page) << this->page_shift;
819
820 /* Must we save the block contents? */
821 if (td->options & NAND_BBT_SAVECONTENT) {
822 /* Make it block aligned */
823 to &= ~(((loff_t)1 << this->bbt_erase_shift) - 1);
824 len = 1 << this->bbt_erase_shift;
825 res = mtd_read(mtd, from: to, len, retlen: &retlen, buf);
826 if (res < 0) {
827 if (retlen != len) {
828 pr_info("nand_bbt: error reading block for writing the bad block table\n");
829 return res;
830 }
831 pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
832 }
833 /* Read oob data */
834 ops.ooblen = (len >> this->page_shift) * mtd->oobsize;
835 ops.oobbuf = &buf[len];
836 res = mtd_read_oob(mtd, from: to + mtd->writesize, ops: &ops);
837 if (res < 0 || ops.oobretlen != ops.ooblen)
838 goto outerr;
839
840 /* Calc the byte offset in the buffer */
841 pageoffs = page - (int)(to >> this->page_shift);
842 offs = pageoffs << this->page_shift;
843 /* Preset the bbt area with 0xff */
844 memset(&buf[offs], 0xff, (size_t)(numblocks >> sft));
845 ooboffs = len + (pageoffs * mtd->oobsize);
846
847 } else if (td->options & NAND_BBT_NO_OOB) {
848 ooboffs = 0;
849 offs = td->len;
850 /* The version byte */
851 if (td->options & NAND_BBT_VERSION)
852 offs++;
853 /* Calc length */
854 len = (size_t)(numblocks >> sft);
855 len += offs;
856 /* Make it page aligned! */
857 len = ALIGN(len, mtd->writesize);
858 /* Preset the buffer with 0xff */
859 memset(buf, 0xff, len);
860 /* Pattern is located at the begin of first page */
861 memcpy(buf, td->pattern, td->len);
862 } else {
863 /* Calc length */
864 len = (size_t)(numblocks >> sft);
865 /* Make it page aligned! */
866 len = ALIGN(len, mtd->writesize);
867 /* Preset the buffer with 0xff */
868 memset(buf, 0xff, len +
869 (len >> this->page_shift)* mtd->oobsize);
870 offs = 0;
871 ooboffs = len;
872 /* Pattern is located in oob area of first page */
873 memcpy(&buf[ooboffs + td->offs], td->pattern, td->len);
874 }
875
876 if (td->options & NAND_BBT_VERSION)
877 buf[ooboffs + td->veroffs] = td->version[chip];
878
879 /* Walk through the memory table */
880 for (i = 0; i < numblocks; i++) {
881 uint8_t dat;
882 int sftcnt = (i << (3 - sft)) & sftmsk;
883 dat = bbt_get_entry(chip: this, block: chip * numblocks + i);
884 /* Do not store the reserved bbt blocks! */
885 buf[offs + (i >> sft)] &= ~(msk[dat] << sftcnt);
886 }
887
888 memset(&einfo, 0, sizeof(einfo));
889 einfo.addr = to;
890 einfo.len = 1 << this->bbt_erase_shift;
891 res = nand_erase_nand(chip: this, instr: &einfo, allowbbt: 1);
892 if (res < 0) {
893 pr_warn("nand_bbt: error while erasing BBT block %d\n",
894 res);
895 mark_bbt_block_bad(this, td, chip, block);
896 continue;
897 }
898
899 res = scan_write_bbt(this, offs: to, len, buf,
900 oob: td->options & NAND_BBT_NO_OOB ?
901 NULL : &buf[len]);
902 if (res < 0) {
903 pr_warn("nand_bbt: error while writing BBT block %d\n",
904 res);
905 mark_bbt_block_bad(this, td, chip, block);
906 continue;
907 }
908
909 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
910 (unsigned long long)to, td->version[chip]);
911
912 /* Mark it as used */
913 td->pages[chip++] = page;
914 }
915 return 0;
916
917 outerr:
918 pr_warn("nand_bbt: error while writing bad block table %d\n", res);
919 return res;
920}
921
922/**
923 * nand_memory_bbt - [GENERIC] create a memory based bad block table
924 * @this: NAND chip object
925 * @bd: descriptor for the good/bad block search pattern
926 *
927 * The function creates a memory based bbt by scanning the device for
928 * manufacturer / software marked good / bad blocks.
929 */
930static inline int nand_memory_bbt(struct nand_chip *this,
931 struct nand_bbt_descr *bd)
932{
933 u8 *pagebuf = nand_get_data_buf(chip: this);
934
935 return create_bbt(this, buf: pagebuf, bd, chip: -1);
936}
937
938/**
939 * check_create - [GENERIC] create and write bbt(s) if necessary
940 * @this: the NAND device
941 * @buf: temporary buffer
942 * @bd: descriptor for the good/bad block search pattern
943 *
944 * The function checks the results of the previous call to read_bbt and creates
945 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
946 * for the chip/device. Update is necessary if one of the tables is missing or
947 * the version nr. of one table is less than the other.
948 */
949static int check_create(struct nand_chip *this, uint8_t *buf,
950 struct nand_bbt_descr *bd)
951{
952 int i, chips, writeops, create, chipsel, res, res2;
953 struct nand_bbt_descr *td = this->bbt_td;
954 struct nand_bbt_descr *md = this->bbt_md;
955 struct nand_bbt_descr *rd, *rd2;
956
957 /* Do we have a bbt per chip? */
958 if (td->options & NAND_BBT_PERCHIP)
959 chips = nanddev_ntargets(nand: &this->base);
960 else
961 chips = 1;
962
963 for (i = 0; i < chips; i++) {
964 writeops = 0;
965 create = 0;
966 rd = NULL;
967 rd2 = NULL;
968 res = res2 = 0;
969 /* Per chip or per device? */
970 chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1;
971 /* Mirrored table available? */
972 if (md) {
973 if (td->pages[i] == -1 && md->pages[i] == -1) {
974 create = 1;
975 writeops = 0x03;
976 } else if (td->pages[i] == -1) {
977 rd = md;
978 writeops = 0x01;
979 } else if (md->pages[i] == -1) {
980 rd = td;
981 writeops = 0x02;
982 } else if (td->version[i] == md->version[i]) {
983 rd = td;
984 if (!(td->options & NAND_BBT_VERSION))
985 rd2 = md;
986 } else if (((int8_t)(td->version[i] - md->version[i])) > 0) {
987 rd = td;
988 writeops = 0x02;
989 } else {
990 rd = md;
991 writeops = 0x01;
992 }
993 } else {
994 if (td->pages[i] == -1) {
995 create = 1;
996 writeops = 0x01;
997 } else {
998 rd = td;
999 }
1000 }
1001
1002 if (create) {
1003 /* Create the bad block table by scanning the device? */
1004 if (!(td->options & NAND_BBT_CREATE))
1005 continue;
1006
1007 /* Create the table in memory by scanning the chip(s) */
1008 if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY))
1009 create_bbt(this, buf, bd, chip: chipsel);
1010
1011 td->version[i] = 1;
1012 if (md)
1013 md->version[i] = 1;
1014 }
1015
1016 /* Read back first? */
1017 if (rd) {
1018 res = read_abs_bbt(this, buf, td: rd, chip: chipsel);
1019 if (mtd_is_eccerr(err: res)) {
1020 /* Mark table as invalid */
1021 rd->pages[i] = -1;
1022 rd->version[i] = 0;
1023 i--;
1024 continue;
1025 }
1026 }
1027 /* If they weren't versioned, read both */
1028 if (rd2) {
1029 res2 = read_abs_bbt(this, buf, td: rd2, chip: chipsel);
1030 if (mtd_is_eccerr(err: res2)) {
1031 /* Mark table as invalid */
1032 rd2->pages[i] = -1;
1033 rd2->version[i] = 0;
1034 i--;
1035 continue;
1036 }
1037 }
1038
1039 /* Scrub the flash table(s)? */
1040 if (mtd_is_bitflip(err: res) || mtd_is_bitflip(err: res2))
1041 writeops = 0x03;
1042
1043 /* Update version numbers before writing */
1044 if (md) {
1045 td->version[i] = max(td->version[i], md->version[i]);
1046 md->version[i] = td->version[i];
1047 }
1048
1049 /* Write the bad block table to the device? */
1050 if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) {
1051 res = write_bbt(this, buf, td, md, chipsel);
1052 if (res < 0)
1053 return res;
1054 }
1055
1056 /* Write the mirror bad block table to the device? */
1057 if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) {
1058 res = write_bbt(this, buf, td: md, md: td, chipsel);
1059 if (res < 0)
1060 return res;
1061 }
1062 }
1063 return 0;
1064}
1065
1066/**
1067 * nand_update_bbt - update bad block table(s)
1068 * @this: the NAND device
1069 * @offs: the offset of the newly marked block
1070 *
1071 * The function updates the bad block table(s).
1072 */
1073static int nand_update_bbt(struct nand_chip *this, loff_t offs)
1074{
1075 struct mtd_info *mtd = nand_to_mtd(chip: this);
1076 int len, res = 0;
1077 int chip, chipsel;
1078 uint8_t *buf;
1079 struct nand_bbt_descr *td = this->bbt_td;
1080 struct nand_bbt_descr *md = this->bbt_md;
1081
1082 if (!this->bbt || !td)
1083 return -EINVAL;
1084
1085 /* Allocate a temporary buffer for one eraseblock incl. oob */
1086 len = (1 << this->bbt_erase_shift);
1087 len += (len >> this->page_shift) * mtd->oobsize;
1088 buf = kmalloc(size: len, GFP_KERNEL);
1089 if (!buf)
1090 return -ENOMEM;
1091
1092 /* Do we have a bbt per chip? */
1093 if (td->options & NAND_BBT_PERCHIP) {
1094 chip = (int)(offs >> this->chip_shift);
1095 chipsel = chip;
1096 } else {
1097 chip = 0;
1098 chipsel = -1;
1099 }
1100
1101 td->version[chip]++;
1102 if (md)
1103 md->version[chip]++;
1104
1105 /* Write the bad block table to the device? */
1106 if (td->options & NAND_BBT_WRITE) {
1107 res = write_bbt(this, buf, td, md, chipsel);
1108 if (res < 0)
1109 goto out;
1110 }
1111 /* Write the mirror bad block table to the device? */
1112 if (md && (md->options & NAND_BBT_WRITE)) {
1113 res = write_bbt(this, buf, td: md, md: td, chipsel);
1114 }
1115
1116 out:
1117 kfree(objp: buf);
1118 return res;
1119}
1120
1121/**
1122 * mark_bbt_region - [GENERIC] mark the bad block table regions
1123 * @this: the NAND device
1124 * @td: bad block table descriptor
1125 *
1126 * The bad block table regions are marked as "bad" to prevent accidental
1127 * erasures / writes. The regions are identified by the mark 0x02.
1128 */
1129static void mark_bbt_region(struct nand_chip *this, struct nand_bbt_descr *td)
1130{
1131 u64 targetsize = nanddev_target_size(nand: &this->base);
1132 struct mtd_info *mtd = nand_to_mtd(chip: this);
1133 int i, j, chips, block, nrblocks, update;
1134 uint8_t oldval;
1135
1136 /* Do we have a bbt per chip? */
1137 if (td->options & NAND_BBT_PERCHIP) {
1138 chips = nanddev_ntargets(nand: &this->base);
1139 nrblocks = (int)(targetsize >> this->bbt_erase_shift);
1140 } else {
1141 chips = 1;
1142 nrblocks = (int)(mtd->size >> this->bbt_erase_shift);
1143 }
1144
1145 for (i = 0; i < chips; i++) {
1146 if ((td->options & NAND_BBT_ABSPAGE) ||
1147 !(td->options & NAND_BBT_WRITE)) {
1148 if (td->pages[i] == -1)
1149 continue;
1150 block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift);
1151 oldval = bbt_get_entry(chip: this, block);
1152 bbt_mark_entry(chip: this, block, BBT_BLOCK_RESERVED);
1153 if ((oldval != BBT_BLOCK_RESERVED) &&
1154 td->reserved_block_code)
1155 nand_update_bbt(this, offs: (loff_t)block <<
1156 this->bbt_erase_shift);
1157 continue;
1158 }
1159 update = 0;
1160 if (td->options & NAND_BBT_LASTBLOCK)
1161 block = ((i + 1) * nrblocks) - td->maxblocks;
1162 else
1163 block = i * nrblocks;
1164 for (j = 0; j < td->maxblocks; j++) {
1165 oldval = bbt_get_entry(chip: this, block);
1166 bbt_mark_entry(chip: this, block, BBT_BLOCK_RESERVED);
1167 if (oldval != BBT_BLOCK_RESERVED)
1168 update = 1;
1169 block++;
1170 }
1171 /*
1172 * If we want reserved blocks to be recorded to flash, and some
1173 * new ones have been marked, then we need to update the stored
1174 * bbts. This should only happen once.
1175 */
1176 if (update && td->reserved_block_code)
1177 nand_update_bbt(this, offs: (loff_t)(block - 1) <<
1178 this->bbt_erase_shift);
1179 }
1180}
1181
1182/**
1183 * verify_bbt_descr - verify the bad block description
1184 * @this: the NAND device
1185 * @bd: the table to verify
1186 *
1187 * This functions performs a few sanity checks on the bad block description
1188 * table.
1189 */
1190static void verify_bbt_descr(struct nand_chip *this, struct nand_bbt_descr *bd)
1191{
1192 u64 targetsize = nanddev_target_size(nand: &this->base);
1193 struct mtd_info *mtd = nand_to_mtd(chip: this);
1194 u32 pattern_len;
1195 u32 bits;
1196 u32 table_size;
1197
1198 if (!bd)
1199 return;
1200
1201 pattern_len = bd->len;
1202 bits = bd->options & NAND_BBT_NRBITS_MSK;
1203
1204 BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) &&
1205 !(this->bbt_options & NAND_BBT_USE_FLASH));
1206 BUG_ON(!bits);
1207
1208 if (bd->options & NAND_BBT_VERSION)
1209 pattern_len++;
1210
1211 if (bd->options & NAND_BBT_NO_OOB) {
1212 BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH));
1213 BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB));
1214 BUG_ON(bd->offs);
1215 if (bd->options & NAND_BBT_VERSION)
1216 BUG_ON(bd->veroffs != bd->len);
1217 BUG_ON(bd->options & NAND_BBT_SAVECONTENT);
1218 }
1219
1220 if (bd->options & NAND_BBT_PERCHIP)
1221 table_size = targetsize >> this->bbt_erase_shift;
1222 else
1223 table_size = mtd->size >> this->bbt_erase_shift;
1224 table_size >>= 3;
1225 table_size *= bits;
1226 if (bd->options & NAND_BBT_NO_OOB)
1227 table_size += pattern_len;
1228 BUG_ON(table_size > (1 << this->bbt_erase_shift));
1229}
1230
1231/**
1232 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1233 * @this: the NAND device
1234 * @bd: descriptor for the good/bad block search pattern
1235 *
1236 * The function checks, if a bad block table(s) is/are already available. If
1237 * not it scans the device for manufacturer marked good / bad blocks and writes
1238 * the bad block table(s) to the selected place.
1239 *
1240 * The bad block table memory is allocated here. It must be freed by calling
1241 * the nand_free_bbt function.
1242 */
1243static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
1244{
1245 struct mtd_info *mtd = nand_to_mtd(chip: this);
1246 int len, res;
1247 uint8_t *buf;
1248 struct nand_bbt_descr *td = this->bbt_td;
1249 struct nand_bbt_descr *md = this->bbt_md;
1250
1251 len = (mtd->size >> (this->bbt_erase_shift + 2)) ? : 1;
1252 /*
1253 * Allocate memory (2bit per block) and clear the memory bad block
1254 * table.
1255 */
1256 this->bbt = kzalloc(size: len, GFP_KERNEL);
1257 if (!this->bbt)
1258 return -ENOMEM;
1259
1260 /*
1261 * If no primary table descriptor is given, scan the device to build a
1262 * memory based bad block table.
1263 */
1264 if (!td) {
1265 if ((res = nand_memory_bbt(this, bd))) {
1266 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1267 goto err_free_bbt;
1268 }
1269 return 0;
1270 }
1271 verify_bbt_descr(this, bd: td);
1272 verify_bbt_descr(this, bd: md);
1273
1274 /* Allocate a temporary buffer for one eraseblock incl. oob */
1275 len = (1 << this->bbt_erase_shift);
1276 len += (len >> this->page_shift) * mtd->oobsize;
1277 buf = vmalloc(size: len);
1278 if (!buf) {
1279 res = -ENOMEM;
1280 goto err_free_bbt;
1281 }
1282
1283 /* Is the bbt at a given page? */
1284 if (td->options & NAND_BBT_ABSPAGE) {
1285 read_abs_bbts(this, buf, td, md);
1286 } else {
1287 /* Search the bad block table using a pattern in oob */
1288 search_read_bbts(this, buf, td, md);
1289 }
1290
1291 res = check_create(this, buf, bd);
1292 if (res)
1293 goto err_free_buf;
1294
1295 /* Prevent the bbt regions from erasing / writing */
1296 mark_bbt_region(this, td);
1297 if (md)
1298 mark_bbt_region(this, td: md);
1299
1300 vfree(addr: buf);
1301 return 0;
1302
1303err_free_buf:
1304 vfree(addr: buf);
1305err_free_bbt:
1306 kfree(objp: this->bbt);
1307 this->bbt = NULL;
1308 return res;
1309}
1310
1311/*
1312 * Define some generic bad / good block scan pattern which are used
1313 * while scanning a device for factory marked good / bad blocks.
1314 */
1315static uint8_t scan_ff_pattern[] = { 0xff, 0xff };
1316
1317/* Generic flash bbt descriptors */
1318static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' };
1319static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' };
1320
1321static struct nand_bbt_descr bbt_main_descr = {
1322 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1323 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1324 .offs = 8,
1325 .len = 4,
1326 .veroffs = 12,
1327 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1328 .pattern = bbt_pattern
1329};
1330
1331static struct nand_bbt_descr bbt_mirror_descr = {
1332 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1333 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
1334 .offs = 8,
1335 .len = 4,
1336 .veroffs = 12,
1337 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1338 .pattern = mirror_pattern
1339};
1340
1341static struct nand_bbt_descr bbt_main_no_oob_descr = {
1342 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1343 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1344 | NAND_BBT_NO_OOB,
1345 .len = 4,
1346 .veroffs = 4,
1347 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1348 .pattern = bbt_pattern
1349};
1350
1351static struct nand_bbt_descr bbt_mirror_no_oob_descr = {
1352 .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
1353 | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP
1354 | NAND_BBT_NO_OOB,
1355 .len = 4,
1356 .veroffs = 4,
1357 .maxblocks = NAND_BBT_SCAN_MAXBLOCKS,
1358 .pattern = mirror_pattern
1359};
1360
1361#define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1362/**
1363 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1364 * @this: NAND chip to create descriptor for
1365 *
1366 * This function allocates and initializes a nand_bbt_descr for BBM detection
1367 * based on the properties of @this. The new descriptor is stored in
1368 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1369 * passed to this function.
1370 */
1371static int nand_create_badblock_pattern(struct nand_chip *this)
1372{
1373 struct nand_bbt_descr *bd;
1374 if (this->badblock_pattern) {
1375 pr_warn("Bad block pattern already allocated; not replacing\n");
1376 return -EINVAL;
1377 }
1378 bd = kzalloc(size: sizeof(*bd), GFP_KERNEL);
1379 if (!bd)
1380 return -ENOMEM;
1381 bd->options = this->bbt_options & BADBLOCK_SCAN_MASK;
1382 bd->offs = this->badblockpos;
1383 bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1;
1384 bd->pattern = scan_ff_pattern;
1385 bd->options |= NAND_BBT_DYNAMICSTRUCT;
1386 this->badblock_pattern = bd;
1387 return 0;
1388}
1389
1390/**
1391 * nand_create_bbt - [NAND Interface] Select a default bad block table for the device
1392 * @this: NAND chip object
1393 *
1394 * This function selects the default bad block table support for the device and
1395 * calls the nand_scan_bbt function.
1396 */
1397int nand_create_bbt(struct nand_chip *this)
1398{
1399 int ret;
1400
1401 /* Is a flash based bad block table requested? */
1402 if (this->bbt_options & NAND_BBT_USE_FLASH) {
1403 /* Use the default pattern descriptors */
1404 if (!this->bbt_td) {
1405 if (this->bbt_options & NAND_BBT_NO_OOB) {
1406 this->bbt_td = &bbt_main_no_oob_descr;
1407 this->bbt_md = &bbt_mirror_no_oob_descr;
1408 } else {
1409 this->bbt_td = &bbt_main_descr;
1410 this->bbt_md = &bbt_mirror_descr;
1411 }
1412 }
1413 } else {
1414 this->bbt_td = NULL;
1415 this->bbt_md = NULL;
1416 }
1417
1418 if (!this->badblock_pattern) {
1419 ret = nand_create_badblock_pattern(this);
1420 if (ret)
1421 return ret;
1422 }
1423
1424 return nand_scan_bbt(this, bd: this->badblock_pattern);
1425}
1426EXPORT_SYMBOL(nand_create_bbt);
1427
1428/**
1429 * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
1430 * @this: NAND chip object
1431 * @offs: offset in the device
1432 */
1433int nand_isreserved_bbt(struct nand_chip *this, loff_t offs)
1434{
1435 int block;
1436
1437 block = (int)(offs >> this->bbt_erase_shift);
1438 return bbt_get_entry(chip: this, block) == BBT_BLOCK_RESERVED;
1439}
1440
1441/**
1442 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1443 * @this: NAND chip object
1444 * @offs: offset in the device
1445 * @allowbbt: allow access to bad block table region
1446 */
1447int nand_isbad_bbt(struct nand_chip *this, loff_t offs, int allowbbt)
1448{
1449 int block, res;
1450
1451 block = (int)(offs >> this->bbt_erase_shift);
1452 res = bbt_get_entry(chip: this, block);
1453
1454 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1455 (unsigned int)offs, block, res);
1456
1457 if (mtd_check_expert_analysis_mode())
1458 return 0;
1459
1460 switch (res) {
1461 case BBT_BLOCK_GOOD:
1462 return 0;
1463 case BBT_BLOCK_WORN:
1464 return 1;
1465 case BBT_BLOCK_RESERVED:
1466 return allowbbt ? 0 : 1;
1467 }
1468 return 1;
1469}
1470
1471/**
1472 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1473 * @this: NAND chip object
1474 * @offs: offset of the bad block
1475 */
1476int nand_markbad_bbt(struct nand_chip *this, loff_t offs)
1477{
1478 int block, ret = 0;
1479
1480 block = (int)(offs >> this->bbt_erase_shift);
1481
1482 /* Mark bad block in memory */
1483 bbt_mark_entry(chip: this, block, BBT_BLOCK_WORN);
1484
1485 /* Update flash-based bad block table */
1486 if (this->bbt_options & NAND_BBT_USE_FLASH)
1487 ret = nand_update_bbt(this, offs);
1488
1489 return ret;
1490}
1491

source code of linux/drivers/mtd/nand/raw/nand_bbt.c