3 * Bad block table support for the NAND driver
5 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
13 * When nand_scan_bbt is called, then it tries to find the bad block table
14 * depending on the options in the BBT descriptor(s). If no flash based BBT
15 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
16 * marked good / bad blocks. This information is used to create a memory BBT.
17 * Once a new bad block is discovered then the "factory" information is updated
19 * If a flash based BBT is specified then the function first tries to find the
20 * BBT on flash. If a BBT is found then the contents are read and the memory
21 * based BBT is created. If a mirrored BBT is selected then the mirror is
22 * searched too and the versions are compared. If the mirror has a greater
23 * version number, then the mirror BBT is used to build the memory based BBT.
24 * If the tables are not versioned, then we "or" the bad block information.
25 * If one of the BBTs is out of date or does not exist it is (re)created.
26 * If no BBT exists at all then the device is scanned for factory marked
27 * good / bad blocks and the bad block tables are created.
29 * For manufacturer created BBTs like the one found on M-SYS DOC devices
30 * the BBT is searched and read but never created
32 * The auto generated bad block table is located in the last good blocks
33 * of the device. The table is mirrored, so it can be updated eventually.
34 * The table is marked in the OOB area with an ident pattern and a version
35 * number which indicates which of both tables is more up to date. If the NAND
36 * controller needs the complete OOB area for the ECC information then the
37 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
38 * course): it moves the ident pattern and the version byte into the data area
39 * and the OOB area will remain untouched.
41 * The table uses 2 bits per block
43 * 00b: block is factory marked bad
44 * 01b, 10b: block is marked bad due to wear
46 * The memory bad block table uses the following scheme:
48 * 01b: block is marked bad due to wear
49 * 10b: block is reserved (to protect the bbt area)
50 * 11b: block is factory marked bad
52 * Multichip devices like DOC store the bad block info per floor.
54 * Following assumptions are made:
55 * - bbts start at a page boundary, if autolocated on a block boundary
56 * - the space necessary for a bbt in FLASH does not exceed a block boundary
62 #include <linux/compat.h>
63 #include <linux/mtd/mtd.h>
64 #include <linux/mtd/bbm.h>
65 #include <linux/mtd/nand.h>
66 #include <linux/bitops.h>
67 #include <linux/string.h>
69 #define BBT_BLOCK_GOOD 0x00
70 #define BBT_BLOCK_WORN 0x01
71 #define BBT_BLOCK_RESERVED 0x02
72 #define BBT_BLOCK_FACTORY_BAD 0x03
74 #define BBT_ENTRY_MASK 0x03
75 #define BBT_ENTRY_SHIFT 2
77 static int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
);
79 static inline uint8_t bbt_get_entry(struct nand_chip
*chip
, int block
)
81 uint8_t entry
= chip
->bbt
[block
>> BBT_ENTRY_SHIFT
];
82 entry
>>= (block
& BBT_ENTRY_MASK
) * 2;
83 return entry
& BBT_ENTRY_MASK
;
86 static inline void bbt_mark_entry(struct nand_chip
*chip
, int block
,
89 uint8_t msk
= (mark
& BBT_ENTRY_MASK
) << ((block
& BBT_ENTRY_MASK
) * 2);
90 chip
->bbt
[block
>> BBT_ENTRY_SHIFT
] |= msk
;
93 static int check_pattern_no_oob(uint8_t *buf
, struct nand_bbt_descr
*td
)
95 if (memcmp(buf
, td
->pattern
, td
->len
))
101 * check_pattern - [GENERIC] check if a pattern is in the buffer
102 * @buf: the buffer to search
103 * @len: the length of buffer to search
104 * @paglen: the pagelength
105 * @td: search pattern descriptor
107 * Check for a pattern at the given place. Used to search bad block tables and
108 * good / bad block identifiers.
110 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
112 if (td
->options
& NAND_BBT_NO_OOB
)
113 return check_pattern_no_oob(buf
, td
);
115 /* Compare the pattern */
116 if (memcmp(buf
+ paglen
+ td
->offs
, td
->pattern
, td
->len
))
123 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
124 * @buf: the buffer to search
125 * @td: search pattern descriptor
127 * Check for a pattern at the given place. Used to search bad block tables and
128 * good / bad block identifiers. Same as check_pattern, but no optional empty
131 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
133 /* Compare the pattern */
134 if (memcmp(buf
+ td
->offs
, td
->pattern
, td
->len
))
140 * add_marker_len - compute the length of the marker in data area
141 * @td: BBT descriptor used for computation
143 * The length will be 0 if the marker is located in OOB area.
145 static u32
add_marker_len(struct nand_bbt_descr
*td
)
149 if (!(td
->options
& NAND_BBT_NO_OOB
))
153 if (td
->options
& NAND_BBT_VERSION
)
159 * read_bbt - [GENERIC] Read the bad block table starting from page
160 * @mtd: MTD device structure
161 * @buf: temporary buffer
162 * @page: the starting page
163 * @num: the number of bbt descriptors to read
164 * @td: the bbt describtion table
165 * @offs: block number offset in the table
167 * Read the bad block table starting from page.
169 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
170 struct nand_bbt_descr
*td
, int offs
)
172 int res
, ret
= 0, i
, j
, act
= 0;
173 struct nand_chip
*this = mtd_to_nand(mtd
);
174 size_t retlen
, len
, totlen
;
176 int bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
177 uint8_t msk
= (uint8_t)((1 << bits
) - 1);
179 int reserved_block_code
= td
->reserved_block_code
;
181 totlen
= (num
* bits
) >> 3;
182 marker_len
= add_marker_len(td
);
183 from
= ((loff_t
)page
) << this->page_shift
;
186 len
= min(totlen
, (size_t)(1 << this->bbt_erase_shift
));
189 * In case the BBT marker is not in the OOB area it
190 * will be just in the first page.
196 res
= mtd_read(mtd
, from
, len
, &retlen
, buf
);
198 if (mtd_is_eccerr(res
)) {
199 pr_info("nand_bbt: ECC error in BBT at 0x%012llx\n",
200 from
& ~mtd
->writesize
);
202 } else if (mtd_is_bitflip(res
)) {
203 pr_info("nand_bbt: corrected error in BBT at 0x%012llx\n",
204 from
& ~mtd
->writesize
);
207 pr_info("nand_bbt: error reading BBT\n");
213 for (i
= 0; i
< len
; i
++) {
214 uint8_t dat
= buf
[i
];
215 for (j
= 0; j
< 8; j
+= bits
, act
++) {
216 uint8_t tmp
= (dat
>> j
) & msk
;
219 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
220 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
221 (loff_t
)(offs
+ act
) <<
222 this->bbt_erase_shift
);
223 bbt_mark_entry(this, offs
+ act
,
225 mtd
->ecc_stats
.bbtblocks
++;
229 * Leave it for now, if it's matured we can
230 * move this message to pr_debug.
232 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
233 (loff_t
)(offs
+ act
) <<
234 this->bbt_erase_shift
);
235 /* Factory marked bad or worn out? */
237 bbt_mark_entry(this, offs
+ act
,
238 BBT_BLOCK_FACTORY_BAD
);
240 bbt_mark_entry(this, offs
+ act
,
242 mtd
->ecc_stats
.badblocks
++;
252 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
253 * @mtd: MTD device structure
254 * @buf: temporary buffer
255 * @td: descriptor for the bad block table
256 * @chip: read the table for a specific chip, -1 read all chips; applies only if
257 * NAND_BBT_PERCHIP option is set
259 * Read the bad block table for all chips starting at a given page. We assume
260 * that the bbt bits are in consecutive order.
262 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
264 struct nand_chip
*this = mtd_to_nand(mtd
);
267 if (td
->options
& NAND_BBT_PERCHIP
) {
269 for (i
= 0; i
< this->numchips
; i
++) {
270 if (chip
== -1 || chip
== i
)
271 res
= read_bbt(mtd
, buf
, td
->pages
[i
],
272 this->chipsize
>> this->bbt_erase_shift
,
276 offs
+= this->chipsize
>> this->bbt_erase_shift
;
279 res
= read_bbt(mtd
, buf
, td
->pages
[0],
280 mtd
->size
>> this->bbt_erase_shift
, td
, 0);
287 /* BBT marker is in the first page, no OOB */
288 static int scan_read_data(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
289 struct nand_bbt_descr
*td
)
295 if (td
->options
& NAND_BBT_VERSION
)
298 return mtd_read(mtd
, offs
, len
, &retlen
, buf
);
302 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
303 * @mtd: MTD device structure
304 * @buf: temporary buffer
305 * @offs: offset at which to scan
306 * @len: length of data region to read
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.
312 static int scan_read_oob(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
315 struct mtd_oob_ops ops
;
318 ops
.mode
= MTD_OPS_PLACE_OOB
;
320 ops
.ooblen
= mtd
->oobsize
;
324 ops
.len
= min(len
, (size_t)mtd
->writesize
);
325 ops
.oobbuf
= buf
+ ops
.len
;
327 res
= mtd_read_oob(mtd
, offs
, &ops
);
329 if (!mtd_is_bitflip_or_eccerr(res
))
331 else if (mtd_is_eccerr(res
) || !ret
)
335 buf
+= mtd
->oobsize
+ mtd
->writesize
;
336 len
-= mtd
->writesize
;
337 offs
+= mtd
->writesize
;
342 static int scan_read(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
343 size_t len
, struct nand_bbt_descr
*td
)
345 if (td
->options
& NAND_BBT_NO_OOB
)
346 return scan_read_data(mtd
, buf
, offs
, td
);
348 return scan_read_oob(mtd
, buf
, offs
, len
);
351 /* Scan write data with oob to flash */
352 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
353 uint8_t *buf
, uint8_t *oob
)
355 struct mtd_oob_ops ops
;
357 ops
.mode
= MTD_OPS_PLACE_OOB
;
359 ops
.ooblen
= mtd
->oobsize
;
364 return mtd_write_oob(mtd
, offs
, &ops
);
367 static u32
bbt_get_ver_offs(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
369 u32 ver_offs
= td
->veroffs
;
371 if (!(td
->options
& NAND_BBT_NO_OOB
))
372 ver_offs
+= mtd
->writesize
;
377 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
378 * @mtd: MTD device structure
379 * @buf: temporary buffer
380 * @td: descriptor for the bad block table
381 * @md: descriptor for the bad block table mirror
383 * Read the bad block table(s) for all chips starting at a given page. We
384 * assume that the bbt bits are in consecutive order.
386 static void read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
387 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
389 struct nand_chip
*this = mtd_to_nand(mtd
);
391 /* Read the primary version, if available */
392 if (td
->options
& NAND_BBT_VERSION
) {
393 scan_read(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
395 td
->version
[0] = buf
[bbt_get_ver_offs(mtd
, td
)];
396 pr_info("Bad block table at page %d, version 0x%02X\n",
397 td
->pages
[0], td
->version
[0]);
400 /* Read the mirror version, if available */
401 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
402 scan_read(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
404 md
->version
[0] = buf
[bbt_get_ver_offs(mtd
, md
)];
405 pr_info("Bad block table at page %d, version 0x%02X\n",
406 md
->pages
[0], md
->version
[0]);
410 /* Scan a given block partially */
411 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
412 loff_t offs
, uint8_t *buf
, int numpages
)
414 struct mtd_oob_ops ops
;
417 ops
.ooblen
= mtd
->oobsize
;
421 ops
.mode
= MTD_OPS_PLACE_OOB
;
423 for (j
= 0; j
< numpages
; j
++) {
425 * Read the full oob until read_oob is fixed to handle single
426 * byte reads for 16 bit buswidth.
428 ret
= mtd_read_oob(mtd
, offs
, &ops
);
429 /* Ignore ECC errors when checking for BBM */
430 if (ret
&& !mtd_is_bitflip_or_eccerr(ret
))
433 if (check_short_pattern(buf
, bd
))
436 offs
+= mtd
->writesize
;
442 * create_bbt - [GENERIC] Create a bad block table by scanning the device
443 * @mtd: MTD device structure
444 * @buf: temporary buffer
445 * @bd: descriptor for the good/bad block search pattern
446 * @chip: create the table for a specific chip, -1 read all chips; applies only
447 * if NAND_BBT_PERCHIP option is set
449 * Create a bad block table by scanning the device for the given good/bad block
452 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
453 struct nand_bbt_descr
*bd
, int chip
)
455 struct nand_chip
*this = mtd_to_nand(mtd
);
456 int i
, numblocks
, numpages
;
460 pr_info("Scanning device for bad blocks\n");
462 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
468 numblocks
= mtd
->size
>> this->bbt_erase_shift
;
472 if (chip
>= this->numchips
) {
473 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
474 chip
+ 1, this->numchips
);
477 numblocks
= this->chipsize
>> this->bbt_erase_shift
;
478 startblock
= chip
* numblocks
;
479 numblocks
+= startblock
;
480 from
= (loff_t
)startblock
<< this->bbt_erase_shift
;
483 if (this->bbt_options
& NAND_BBT_SCANLASTPAGE
)
484 from
+= mtd
->erasesize
- (mtd
->writesize
* numpages
);
486 for (i
= startblock
; i
< numblocks
; i
++) {
489 BUG_ON(bd
->options
& NAND_BBT_NO_OOB
);
491 ret
= scan_block_fast(mtd
, bd
, from
, buf
, numpages
);
496 bbt_mark_entry(this, i
, BBT_BLOCK_FACTORY_BAD
);
497 pr_warn("Bad eraseblock %d at 0x%012llx\n",
498 i
, (unsigned long long)from
);
499 mtd
->ecc_stats
.badblocks
++;
502 from
+= (1 << this->bbt_erase_shift
);
508 * search_bbt - [GENERIC] scan the device for a specific bad block table
509 * @mtd: MTD device structure
510 * @buf: temporary buffer
511 * @td: descriptor for the bad block table
513 * Read the bad block table by searching for a given ident pattern. Search is
514 * preformed either from the beginning up or from the end of the device
515 * downwards. The search starts always at the start of a block. If the option
516 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
517 * the bad block information of this chip. This is necessary to provide support
518 * for certain DOC devices.
520 * The bbt ident pattern resides in the oob area of the first page in a block.
522 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
524 struct nand_chip
*this = mtd_to_nand(mtd
);
526 int startblock
, block
, dir
;
527 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
529 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
531 /* Search direction top -> down? */
532 if (td
->options
& NAND_BBT_LASTBLOCK
) {
533 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
540 /* Do we have a bbt per chip? */
541 if (td
->options
& NAND_BBT_PERCHIP
) {
542 chips
= this->numchips
;
543 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
544 startblock
&= bbtblocks
- 1;
547 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
550 for (i
= 0; i
< chips
; i
++) {
551 /* Reset version information */
554 /* Scan the maximum number of blocks */
555 for (block
= 0; block
< td
->maxblocks
; block
++) {
557 int actblock
= startblock
+ dir
* block
;
558 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
560 /* Read first page */
561 scan_read(mtd
, buf
, offs
, mtd
->writesize
, td
);
562 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
563 td
->pages
[i
] = actblock
<< blocktopage
;
564 if (td
->options
& NAND_BBT_VERSION
) {
565 offs
= bbt_get_ver_offs(mtd
, td
);
566 td
->version
[i
] = buf
[offs
];
571 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
573 /* Check, if we found a bbt for each requested chip */
574 for (i
= 0; i
< chips
; i
++) {
575 if (td
->pages
[i
] == -1)
576 pr_warn("Bad block table not found for chip %d\n", i
);
578 pr_info("Bad block table found at page %d, version 0x%02X\n",
579 td
->pages
[i
], td
->version
[i
]);
585 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
586 * @mtd: MTD device structure
587 * @buf: temporary buffer
588 * @td: descriptor for the bad block table
589 * @md: descriptor for the bad block table mirror
591 * Search and read the bad block table(s).
593 static void search_read_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
594 struct nand_bbt_descr
*td
,
595 struct nand_bbt_descr
*md
)
597 /* Search the primary table */
598 search_bbt(mtd
, buf
, td
);
600 /* Search the mirror table */
602 search_bbt(mtd
, buf
, md
);
606 * write_bbt - [GENERIC] (Re)write the bad block table
607 * @mtd: MTD device structure
608 * @buf: temporary buffer
609 * @td: descriptor for the bad block table
610 * @md: descriptor for the bad block table mirror
611 * @chipsel: selector for a specific chip, -1 for all
613 * (Re)write the bad block table.
615 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
616 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
619 struct nand_chip
*this = mtd_to_nand(mtd
);
620 struct erase_info einfo
;
621 int i
, res
, chip
= 0;
622 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
623 int nrchips
, pageoffs
, ooboffs
;
625 uint8_t rcode
= td
->reserved_block_code
;
626 size_t retlen
, len
= 0;
628 struct mtd_oob_ops ops
;
630 ops
.ooblen
= mtd
->oobsize
;
633 ops
.mode
= MTD_OPS_PLACE_OOB
;
637 /* Write bad block table per chip rather than per device? */
638 if (td
->options
& NAND_BBT_PERCHIP
) {
639 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
640 /* Full device write or specific chip? */
642 nrchips
= this->numchips
;
644 nrchips
= chipsel
+ 1;
648 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
652 /* Loop through the chips */
653 for (; chip
< nrchips
; chip
++) {
655 * There was already a version of the table, reuse the page
656 * This applies for absolute placement too, as we have the
657 * page nr. in td->pages.
659 if (td
->pages
[chip
] != -1) {
660 page
= td
->pages
[chip
];
665 * Automatic placement of the bad block table. Search direction
668 if (td
->options
& NAND_BBT_LASTBLOCK
) {
669 startblock
= numblocks
* (chip
+ 1) - 1;
672 startblock
= chip
* numblocks
;
676 for (i
= 0; i
< td
->maxblocks
; i
++) {
677 int block
= startblock
+ dir
* i
;
678 /* Check, if the block is bad */
679 switch (bbt_get_entry(this, block
)) {
681 case BBT_BLOCK_FACTORY_BAD
:
685 (this->bbt_erase_shift
- this->page_shift
);
686 /* Check, if the block is used by the mirror table */
687 if (!md
|| md
->pages
[chip
] != page
)
690 pr_err("No space left to write bad block table\n");
694 /* Set up shift count and masks for the flash table */
695 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
698 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
701 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
704 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
707 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
710 default: return -EINVAL
;
713 to
= ((loff_t
)page
) << this->page_shift
;
715 /* Must we save the block contents? */
716 if (td
->options
& NAND_BBT_SAVECONTENT
) {
717 /* Make it block aligned */
718 to
&= ~(((loff_t
)1 << this->bbt_erase_shift
) - 1);
719 len
= 1 << this->bbt_erase_shift
;
720 res
= mtd_read(mtd
, to
, len
, &retlen
, buf
);
723 pr_info("nand_bbt: error reading block for writing the bad block table\n");
726 pr_warn("nand_bbt: ECC error while reading block for writing bad block table\n");
729 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
730 ops
.oobbuf
= &buf
[len
];
731 res
= mtd_read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
732 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
735 /* Calc the byte offset in the buffer */
736 pageoffs
= page
- (int)(to
>> this->page_shift
);
737 offs
= pageoffs
<< this->page_shift
;
738 /* Preset the bbt area with 0xff */
739 memset(&buf
[offs
], 0xff, (size_t)(numblocks
>> sft
));
740 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
742 } else if (td
->options
& NAND_BBT_NO_OOB
) {
745 /* The version byte */
746 if (td
->options
& NAND_BBT_VERSION
)
749 len
= (size_t)(numblocks
>> sft
);
751 /* Make it page aligned! */
752 len
= ALIGN(len
, mtd
->writesize
);
753 /* Preset the buffer with 0xff */
754 memset(buf
, 0xff, len
);
755 /* Pattern is located at the begin of first page */
756 memcpy(buf
, td
->pattern
, td
->len
);
759 len
= (size_t)(numblocks
>> sft
);
760 /* Make it page aligned! */
761 len
= ALIGN(len
, mtd
->writesize
);
762 /* Preset the buffer with 0xff */
763 memset(buf
, 0xff, len
+
764 (len
>> this->page_shift
)* mtd
->oobsize
);
767 /* Pattern is located in oob area of first page */
768 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
771 if (td
->options
& NAND_BBT_VERSION
)
772 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
774 /* Walk through the memory table */
775 for (i
= 0; i
< numblocks
; i
++) {
777 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
778 dat
= bbt_get_entry(this, chip
* numblocks
+ i
);
779 /* Do not store the reserved bbt blocks! */
780 buf
[offs
+ (i
>> sft
)] &= ~(msk
[dat
] << sftcnt
);
783 memset(&einfo
, 0, sizeof(einfo
));
786 einfo
.len
= 1 << this->bbt_erase_shift
;
787 res
= nand_erase_nand(mtd
, &einfo
, 1);
791 res
= scan_write_bbt(mtd
, to
, len
, buf
,
792 td
->options
& NAND_BBT_NO_OOB
? NULL
:
797 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
798 (unsigned long long)to
, td
->version
[chip
]);
800 /* Mark it as used */
801 td
->pages
[chip
] = page
;
806 pr_warn("nand_bbt: error while writing bad block table %d\n", res
);
811 * nand_memory_bbt - [GENERIC] create a memory based bad block table
812 * @mtd: MTD device structure
813 * @bd: descriptor for the good/bad block search pattern
815 * The function creates a memory based bbt by scanning the device for
816 * manufacturer / software marked good / bad blocks.
818 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
820 struct nand_chip
*this = mtd_to_nand(mtd
);
822 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
826 * check_create - [GENERIC] create and write bbt(s) if necessary
827 * @mtd: MTD device structure
828 * @buf: temporary buffer
829 * @bd: descriptor for the good/bad block search pattern
831 * The function checks the results of the previous call to read_bbt and creates
832 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
833 * for the chip/device. Update is necessary if one of the tables is missing or
834 * the version nr. of one table is less than the other.
836 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
838 int i
, chips
, writeops
, create
, chipsel
, res
, res2
;
839 struct nand_chip
*this = mtd_to_nand(mtd
);
840 struct nand_bbt_descr
*td
= this->bbt_td
;
841 struct nand_bbt_descr
*md
= this->bbt_md
;
842 struct nand_bbt_descr
*rd
, *rd2
;
844 /* Do we have a bbt per chip? */
845 if (td
->options
& NAND_BBT_PERCHIP
)
846 chips
= this->numchips
;
850 for (i
= 0; i
< chips
; i
++) {
856 /* Per chip or per device? */
857 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
858 /* Mirrored table available? */
860 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
863 } else if (td
->pages
[i
] == -1) {
866 } else if (md
->pages
[i
] == -1) {
869 } else if (td
->version
[i
] == md
->version
[i
]) {
871 if (!(td
->options
& NAND_BBT_VERSION
))
873 } else if (((int8_t)(td
->version
[i
] - md
->version
[i
])) > 0) {
881 if (td
->pages
[i
] == -1) {
890 /* Create the bad block table by scanning the device? */
891 if (!(td
->options
& NAND_BBT_CREATE
))
894 /* Create the table in memory by scanning the chip(s) */
895 if (!(this->bbt_options
& NAND_BBT_CREATE_EMPTY
))
896 create_bbt(mtd
, buf
, bd
, chipsel
);
903 /* Read back first? */
905 res
= read_abs_bbt(mtd
, buf
, rd
, chipsel
);
906 if (mtd_is_eccerr(res
)) {
907 /* Mark table as invalid */
914 /* If they weren't versioned, read both */
916 res2
= read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
917 if (mtd_is_eccerr(res2
)) {
918 /* Mark table as invalid */
926 /* Scrub the flash table(s)? */
927 if (mtd_is_bitflip(res
) || mtd_is_bitflip(res2
))
930 /* Update version numbers before writing */
932 td
->version
[i
] = max(td
->version
[i
], md
->version
[i
]);
933 md
->version
[i
] = td
->version
[i
];
936 /* Write the bad block table to the device? */
937 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
938 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
943 /* Write the mirror bad block table to the device? */
944 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
945 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
954 * mark_bbt_regions - [GENERIC] mark the bad block table regions
955 * @mtd: MTD device structure
956 * @td: bad block table descriptor
958 * The bad block table regions are marked as "bad" to prevent accidental
959 * erasures / writes. The regions are identified by the mark 0x02.
961 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
963 struct nand_chip
*this = mtd_to_nand(mtd
);
964 int i
, j
, chips
, block
, nrblocks
, update
;
967 /* Do we have a bbt per chip? */
968 if (td
->options
& NAND_BBT_PERCHIP
) {
969 chips
= this->numchips
;
970 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
973 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
976 for (i
= 0; i
< chips
; i
++) {
977 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
978 !(td
->options
& NAND_BBT_WRITE
)) {
979 if (td
->pages
[i
] == -1)
981 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
982 oldval
= bbt_get_entry(this, block
);
983 bbt_mark_entry(this, block
, BBT_BLOCK_RESERVED
);
984 if ((oldval
!= BBT_BLOCK_RESERVED
) &&
985 td
->reserved_block_code
)
986 nand_update_bbt(mtd
, (loff_t
)block
<<
987 this->bbt_erase_shift
);
991 if (td
->options
& NAND_BBT_LASTBLOCK
)
992 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
994 block
= i
* nrblocks
;
995 for (j
= 0; j
< td
->maxblocks
; j
++) {
996 oldval
= bbt_get_entry(this, block
);
997 bbt_mark_entry(this, block
, BBT_BLOCK_RESERVED
);
998 if (oldval
!= BBT_BLOCK_RESERVED
)
1003 * If we want reserved blocks to be recorded to flash, and some
1004 * new ones have been marked, then we need to update the stored
1005 * bbts. This should only happen once.
1007 if (update
&& td
->reserved_block_code
)
1008 nand_update_bbt(mtd
, (loff_t
)(block
- 1) <<
1009 this->bbt_erase_shift
);
1014 * verify_bbt_descr - verify the bad block description
1015 * @mtd: MTD device structure
1016 * @bd: the table to verify
1018 * This functions performs a few sanity checks on the bad block description
1021 static void verify_bbt_descr(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1023 struct nand_chip
*this = mtd_to_nand(mtd
);
1031 pattern_len
= bd
->len
;
1032 bits
= bd
->options
& NAND_BBT_NRBITS_MSK
;
1034 BUG_ON((this->bbt_options
& NAND_BBT_NO_OOB
) &&
1035 !(this->bbt_options
& NAND_BBT_USE_FLASH
));
1038 if (bd
->options
& NAND_BBT_VERSION
)
1041 if (bd
->options
& NAND_BBT_NO_OOB
) {
1042 BUG_ON(!(this->bbt_options
& NAND_BBT_USE_FLASH
));
1043 BUG_ON(!(this->bbt_options
& NAND_BBT_NO_OOB
));
1045 if (bd
->options
& NAND_BBT_VERSION
)
1046 BUG_ON(bd
->veroffs
!= bd
->len
);
1047 BUG_ON(bd
->options
& NAND_BBT_SAVECONTENT
);
1050 if (bd
->options
& NAND_BBT_PERCHIP
)
1051 table_size
= this->chipsize
>> this->bbt_erase_shift
;
1053 table_size
= mtd
->size
>> this->bbt_erase_shift
;
1056 if (bd
->options
& NAND_BBT_NO_OOB
)
1057 table_size
+= pattern_len
;
1058 BUG_ON(table_size
> (1 << this->bbt_erase_shift
));
1062 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1063 * @mtd: MTD device structure
1064 * @bd: descriptor for the good/bad block search pattern
1066 * The function checks, if a bad block table(s) is/are already available. If
1067 * not it scans the device for manufacturer marked good / bad blocks and writes
1068 * the bad block table(s) to the selected place.
1070 * The bad block table memory is allocated here. It must be freed by calling
1071 * the nand_free_bbt function.
1073 static int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1075 struct nand_chip
*this = mtd_to_nand(mtd
);
1078 struct nand_bbt_descr
*td
= this->bbt_td
;
1079 struct nand_bbt_descr
*md
= this->bbt_md
;
1081 len
= (mtd
->size
>> (this->bbt_erase_shift
+ 2)) ? : 1;
1083 * Allocate memory (2bit per block) and clear the memory bad block
1086 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1091 * If no primary table decriptor is given, scan the device to build a
1092 * memory based bad block table.
1095 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1096 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1101 verify_bbt_descr(mtd
, td
);
1102 verify_bbt_descr(mtd
, md
);
1104 /* Allocate a temporary buffer for one eraseblock incl. oob */
1105 len
= (1 << this->bbt_erase_shift
);
1106 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1113 /* Is the bbt at a given page? */
1114 if (td
->options
& NAND_BBT_ABSPAGE
) {
1115 read_abs_bbts(mtd
, buf
, td
, md
);
1117 /* Search the bad block table using a pattern in oob */
1118 search_read_bbts(mtd
, buf
, td
, md
);
1121 res
= check_create(mtd
, buf
, bd
);
1125 /* Prevent the bbt regions from erasing / writing */
1126 mark_bbt_region(mtd
, td
);
1128 mark_bbt_region(mtd
, md
);
1140 * nand_update_bbt - update bad block table(s)
1141 * @mtd: MTD device structure
1142 * @offs: the offset of the newly marked block
1144 * The function updates the bad block table(s).
1146 static int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1148 struct nand_chip
*this = mtd_to_nand(mtd
);
1152 struct nand_bbt_descr
*td
= this->bbt_td
;
1153 struct nand_bbt_descr
*md
= this->bbt_md
;
1155 if (!this->bbt
|| !td
)
1158 /* Allocate a temporary buffer for one eraseblock incl. oob */
1159 len
= (1 << this->bbt_erase_shift
);
1160 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1161 buf
= kmalloc(len
, GFP_KERNEL
);
1165 /* Do we have a bbt per chip? */
1166 if (td
->options
& NAND_BBT_PERCHIP
) {
1167 chip
= (int)(offs
>> this->chip_shift
);
1174 td
->version
[chip
]++;
1176 md
->version
[chip
]++;
1178 /* Write the bad block table to the device? */
1179 if (td
->options
& NAND_BBT_WRITE
) {
1180 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1184 /* Write the mirror bad block table to the device? */
1185 if (md
&& (md
->options
& NAND_BBT_WRITE
)) {
1186 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1195 * Define some generic bad / good block scan pattern which are used
1196 * while scanning a device for factory marked good / bad blocks.
1198 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1200 /* Generic flash bbt descriptors */
1201 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1202 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1204 static struct nand_bbt_descr bbt_main_descr
= {
1205 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1206 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1210 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1211 .pattern
= bbt_pattern
1214 static struct nand_bbt_descr bbt_mirror_descr
= {
1215 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1216 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1220 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1221 .pattern
= mirror_pattern
1224 static struct nand_bbt_descr bbt_main_no_oob_descr
= {
1225 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1226 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1230 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1231 .pattern
= bbt_pattern
1234 static struct nand_bbt_descr bbt_mirror_no_oob_descr
= {
1235 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1236 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1240 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1241 .pattern
= mirror_pattern
1244 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1246 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1247 * @this: NAND chip to create descriptor for
1249 * This function allocates and initializes a nand_bbt_descr for BBM detection
1250 * based on the properties of @this. The new descriptor is stored in
1251 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1252 * passed to this function.
1254 static int nand_create_badblock_pattern(struct nand_chip
*this)
1256 struct nand_bbt_descr
*bd
;
1257 if (this->badblock_pattern
) {
1258 pr_warn("Bad block pattern already allocated; not replacing\n");
1261 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1264 bd
->options
= this->bbt_options
& BADBLOCK_SCAN_MASK
;
1265 bd
->offs
= this->badblockpos
;
1266 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1267 bd
->pattern
= scan_ff_pattern
;
1268 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1269 this->badblock_pattern
= bd
;
1274 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1275 * @mtd: MTD device structure
1277 * This function selects the default bad block table support for the device and
1278 * calls the nand_scan_bbt function.
1280 int nand_default_bbt(struct mtd_info
*mtd
)
1282 struct nand_chip
*this = mtd_to_nand(mtd
);
1285 /* Is a flash based bad block table requested? */
1286 if (this->bbt_options
& NAND_BBT_USE_FLASH
) {
1287 /* Use the default pattern descriptors */
1288 if (!this->bbt_td
) {
1289 if (this->bbt_options
& NAND_BBT_NO_OOB
) {
1290 this->bbt_td
= &bbt_main_no_oob_descr
;
1291 this->bbt_md
= &bbt_mirror_no_oob_descr
;
1293 this->bbt_td
= &bbt_main_descr
;
1294 this->bbt_md
= &bbt_mirror_descr
;
1298 this->bbt_td
= NULL
;
1299 this->bbt_md
= NULL
;
1302 if (!this->badblock_pattern
) {
1303 ret
= nand_create_badblock_pattern(this);
1308 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1312 * nand_isreserved_bbt - [NAND Interface] Check if a block is reserved
1313 * @mtd: MTD device structure
1314 * @offs: offset in the device
1316 int nand_isreserved_bbt(struct mtd_info
*mtd
, loff_t offs
)
1318 struct nand_chip
*this = mtd_to_nand(mtd
);
1321 block
= (int)(offs
>> this->bbt_erase_shift
);
1322 return bbt_get_entry(this, block
) == BBT_BLOCK_RESERVED
;
1326 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1327 * @mtd: MTD device structure
1328 * @offs: offset in the device
1329 * @allowbbt: allow access to bad block table region
1331 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1333 struct nand_chip
*this = mtd_to_nand(mtd
);
1336 block
= (int)(offs
>> this->bbt_erase_shift
);
1337 res
= bbt_get_entry(this, block
);
1339 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1340 (unsigned int)offs
, block
, res
);
1343 case BBT_BLOCK_GOOD
:
1345 case BBT_BLOCK_WORN
:
1347 case BBT_BLOCK_RESERVED
:
1348 return allowbbt
? 0 : 1;
1354 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1355 * @mtd: MTD device structure
1356 * @offs: offset of the bad block
1358 int nand_markbad_bbt(struct mtd_info
*mtd
, loff_t offs
)
1360 struct nand_chip
*this = mtd_to_nand(mtd
);
1363 block
= (int)(offs
>> this->bbt_erase_shift
);
1365 /* Mark bad block in memory */
1366 bbt_mark_entry(this, block
, BBT_BLOCK_WORN
);
1368 /* Update flash-based bad block table */
1369 if (this->bbt_options
& NAND_BBT_USE_FLASH
)
1370 ret
= nand_update_bbt(mtd
, offs
);