2 * drivers/mtd/nand_bbt.c
5 * Bad block table support for the NAND driver
7 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
15 * When nand_scan_bbt is called, then it tries to find the bad block table
16 * depending on the options in the BBT descriptor(s). If no flash based BBT
17 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
18 * marked good / bad blocks. This information is used to create a memory BBT.
19 * Once a new bad block is discovered then the "factory" information is updated
21 * If a flash based BBT is specified then the function first tries to find the
22 * BBT on flash. If a BBT is found then the contents are read and the memory
23 * based BBT is created. If a mirrored BBT is selected then the mirror is
24 * searched too and the versions are compared. If the mirror has a greater
25 * version number, then the mirror BBT is used to build the memory based BBT.
26 * If the tables are not versioned, then we "or" the bad block information.
27 * If one of the BBTs is out of date or does not exist it is (re)created.
28 * If no BBT exists at all then the device is scanned for factory marked
29 * good / bad blocks and the bad block tables are created.
31 * For manufacturer created BBTs like the one found on M-SYS DOC devices
32 * the BBT is searched and read but never created
34 * The auto generated bad block table is located in the last good blocks
35 * of the device. The table is mirrored, so it can be updated eventually.
36 * The table is marked in the OOB area with an ident pattern and a version
37 * number which indicates which of both tables is more up to date. If the NAND
38 * controller needs the complete OOB area for the ECC information then the
39 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
40 * course): it moves the ident pattern and the version byte into the data area
41 * and the OOB area will remain untouched.
43 * The table uses 2 bits per block
45 * 00b: block is factory marked bad
46 * 01b, 10b: block is marked bad due to wear
48 * The memory bad block table uses the following scheme:
50 * 01b: block is marked bad due to wear
51 * 10b: block is reserved (to protect the bbt area)
52 * 11b: block is factory marked bad
54 * Multichip devices like DOC store the bad block info per floor.
56 * Following assumptions are made:
57 * - bbts start at a page boundary, if autolocated on a block boundary
58 * - the space necessary for a bbt in FLASH does not exceed a block boundary
62 #include <linux/slab.h>
63 #include <linux/types.h>
64 #include <linux/mtd/mtd.h>
65 #include <linux/mtd/bbm.h>
66 #include <linux/mtd/nand.h>
67 #include <linux/mtd/nand_ecc.h>
68 #include <linux/bitops.h>
69 #include <linux/delay.h>
70 #include <linux/vmalloc.h>
71 #include <linux/export.h>
72 #include <linux/string.h>
74 #define BBT_BLOCK_GOOD 0x00
75 #define BBT_BLOCK_WORN 0x01
76 #define BBT_BLOCK_RESERVED 0x02
77 #define BBT_BLOCK_FACTORY_BAD 0x03
79 #define BBT_ENTRY_MASK 0x03
80 #define BBT_ENTRY_SHIFT 2
82 static inline uint8_t bbt_get_entry(struct nand_chip
*chip
, int block
)
84 uint8_t entry
= chip
->bbt
[block
>> BBT_ENTRY_SHIFT
];
85 entry
>>= (block
& BBT_ENTRY_MASK
) * 2;
86 return entry
& BBT_ENTRY_MASK
;
89 static inline void bbt_mark_entry(struct nand_chip
*chip
, int block
,
92 uint8_t msk
= (mark
& BBT_ENTRY_MASK
) << ((block
& BBT_ENTRY_MASK
) * 2);
93 chip
->bbt
[block
>> BBT_ENTRY_SHIFT
] |= msk
;
96 static int check_pattern_no_oob(uint8_t *buf
, struct nand_bbt_descr
*td
)
98 if (memcmp(buf
, td
->pattern
, td
->len
))
104 * check_pattern - [GENERIC] check if a pattern is in the buffer
105 * @buf: the buffer to search
106 * @len: the length of buffer to search
107 * @paglen: the pagelength
108 * @td: search pattern descriptor
110 * Check for a pattern at the given place. Used to search bad block tables and
111 * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if
112 * all bytes except the pattern area contain 0xff.
114 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
119 if (td
->options
& NAND_BBT_NO_OOB
)
120 return check_pattern_no_oob(buf
, td
);
122 end
= paglen
+ td
->offs
;
123 if (td
->options
& NAND_BBT_SCANEMPTY
)
124 if (memchr_inv(p
, 0xff, end
))
128 /* Compare the pattern */
129 if (memcmp(p
, td
->pattern
, td
->len
))
132 if (td
->options
& NAND_BBT_SCANEMPTY
) {
135 if (memchr_inv(p
, 0xff, len
- end
))
142 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
143 * @buf: the buffer to search
144 * @td: search pattern descriptor
146 * Check for a pattern at the given place. Used to search bad block tables and
147 * good / bad block identifiers. Same as check_pattern, but no optional empty
150 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
152 /* Compare the pattern */
153 if (memcmp(buf
+ td
->offs
, td
->pattern
, td
->len
))
159 * add_marker_len - compute the length of the marker in data area
160 * @td: BBT descriptor used for computation
162 * The length will be 0 if the marker is located in OOB area.
164 static u32
add_marker_len(struct nand_bbt_descr
*td
)
168 if (!(td
->options
& NAND_BBT_NO_OOB
))
172 if (td
->options
& NAND_BBT_VERSION
)
178 * read_bbt - [GENERIC] Read the bad block table starting from page
179 * @mtd: MTD device structure
180 * @buf: temporary buffer
181 * @page: the starting page
182 * @num: the number of bbt descriptors to read
183 * @td: the bbt describtion table
184 * @offs: block number offset in the table
186 * Read the bad block table starting from page.
188 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
189 struct nand_bbt_descr
*td
, int offs
)
191 int res
, ret
= 0, i
, j
, act
= 0;
192 struct nand_chip
*this = mtd
->priv
;
193 size_t retlen
, len
, totlen
;
195 int bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
196 uint8_t msk
= (uint8_t)((1 << bits
) - 1);
198 int reserved_block_code
= td
->reserved_block_code
;
200 totlen
= (num
* bits
) >> 3;
201 marker_len
= add_marker_len(td
);
202 from
= ((loff_t
)page
) << this->page_shift
;
205 len
= min(totlen
, (size_t)(1 << this->bbt_erase_shift
));
208 * In case the BBT marker is not in the OOB area it
209 * will be just in the first page.
215 res
= mtd_read(mtd
, from
, len
, &retlen
, buf
);
217 if (mtd_is_eccerr(res
)) {
218 pr_info("nand_bbt: ECC error in BBT at "
219 "0x%012llx\n", from
& ~mtd
->writesize
);
221 } else if (mtd_is_bitflip(res
)) {
222 pr_info("nand_bbt: corrected error in BBT at "
223 "0x%012llx\n", from
& ~mtd
->writesize
);
226 pr_info("nand_bbt: error reading BBT\n");
232 for (i
= 0; i
< len
; i
++) {
233 uint8_t dat
= buf
[i
];
234 for (j
= 0; j
< 8; j
+= bits
, act
++) {
235 uint8_t tmp
= (dat
>> j
) & msk
;
238 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
239 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
240 (loff_t
)(offs
+ act
) <<
241 this->bbt_erase_shift
);
242 bbt_mark_entry(this, offs
+ act
,
244 mtd
->ecc_stats
.bbtblocks
++;
248 * Leave it for now, if it's matured we can
249 * move this message to pr_debug.
251 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
252 (loff_t
)(offs
+ act
) <<
253 this->bbt_erase_shift
);
254 /* Factory marked bad or worn out? */
256 bbt_mark_entry(this, offs
+ act
,
257 BBT_BLOCK_FACTORY_BAD
);
259 bbt_mark_entry(this, offs
+ act
,
261 mtd
->ecc_stats
.badblocks
++;
271 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
272 * @mtd: MTD device structure
273 * @buf: temporary buffer
274 * @td: descriptor for the bad block table
275 * @chip: read the table for a specific chip, -1 read all chips; applies only if
276 * NAND_BBT_PERCHIP option is set
278 * Read the bad block table for all chips starting at a given page. We assume
279 * that the bbt bits are in consecutive order.
281 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
283 struct nand_chip
*this = mtd
->priv
;
286 if (td
->options
& NAND_BBT_PERCHIP
) {
288 for (i
= 0; i
< this->numchips
; i
++) {
289 if (chip
== -1 || chip
== i
)
290 res
= read_bbt(mtd
, buf
, td
->pages
[i
],
291 this->chipsize
>> this->bbt_erase_shift
,
295 offs
+= this->chipsize
>> this->bbt_erase_shift
;
298 res
= read_bbt(mtd
, buf
, td
->pages
[0],
299 mtd
->size
>> this->bbt_erase_shift
, td
, 0);
306 /* BBT marker is in the first page, no OOB */
307 static int scan_read_data(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
308 struct nand_bbt_descr
*td
)
314 if (td
->options
& NAND_BBT_VERSION
)
317 return mtd_read(mtd
, offs
, len
, &retlen
, buf
);
321 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
322 * @mtd: MTD device structure
323 * @buf: temporary buffer
324 * @offs: offset at which to scan
325 * @len: length of data region to read
327 * Scan read data from data+OOB. May traverse multiple pages, interleaving
328 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
329 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
331 static int scan_read_oob(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
334 struct mtd_oob_ops ops
;
337 ops
.mode
= MTD_OPS_PLACE_OOB
;
339 ops
.ooblen
= mtd
->oobsize
;
343 ops
.len
= min(len
, (size_t)mtd
->writesize
);
344 ops
.oobbuf
= buf
+ ops
.len
;
346 res
= mtd_read_oob(mtd
, offs
, &ops
);
348 if (!mtd_is_bitflip_or_eccerr(res
))
350 else if (mtd_is_eccerr(res
) || !ret
)
354 buf
+= mtd
->oobsize
+ mtd
->writesize
;
355 len
-= mtd
->writesize
;
356 offs
+= mtd
->writesize
;
361 static int scan_read(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
362 size_t len
, struct nand_bbt_descr
*td
)
364 if (td
->options
& NAND_BBT_NO_OOB
)
365 return scan_read_data(mtd
, buf
, offs
, td
);
367 return scan_read_oob(mtd
, buf
, offs
, len
);
370 /* Scan write data with oob to flash */
371 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
372 uint8_t *buf
, uint8_t *oob
)
374 struct mtd_oob_ops ops
;
376 ops
.mode
= MTD_OPS_PLACE_OOB
;
378 ops
.ooblen
= mtd
->oobsize
;
383 return mtd_write_oob(mtd
, offs
, &ops
);
386 static u32
bbt_get_ver_offs(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
388 u32 ver_offs
= td
->veroffs
;
390 if (!(td
->options
& NAND_BBT_NO_OOB
))
391 ver_offs
+= mtd
->writesize
;
396 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
397 * @mtd: MTD device structure
398 * @buf: temporary buffer
399 * @td: descriptor for the bad block table
400 * @md: descriptor for the bad block table mirror
402 * Read the bad block table(s) for all chips starting at a given page. We
403 * assume that the bbt bits are in consecutive order.
405 static void read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
406 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
408 struct nand_chip
*this = mtd
->priv
;
410 /* Read the primary version, if available */
411 if (td
->options
& NAND_BBT_VERSION
) {
412 scan_read(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
414 td
->version
[0] = buf
[bbt_get_ver_offs(mtd
, td
)];
415 pr_info("Bad block table at page %d, version 0x%02X\n",
416 td
->pages
[0], td
->version
[0]);
419 /* Read the mirror version, if available */
420 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
421 scan_read(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
423 md
->version
[0] = buf
[bbt_get_ver_offs(mtd
, md
)];
424 pr_info("Bad block table at page %d, version 0x%02X\n",
425 md
->pages
[0], md
->version
[0]);
429 /* Scan a given block full */
430 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
431 loff_t offs
, uint8_t *buf
, size_t readlen
,
432 int scanlen
, int numpages
)
436 ret
= scan_read_oob(mtd
, buf
, offs
, readlen
);
437 /* Ignore ECC errors when checking for BBM */
438 if (ret
&& !mtd_is_bitflip_or_eccerr(ret
))
441 for (j
= 0; j
< numpages
; j
++, buf
+= scanlen
) {
442 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
448 /* Scan a given block partially */
449 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
450 loff_t offs
, uint8_t *buf
, int numpages
)
452 struct mtd_oob_ops ops
;
455 ops
.ooblen
= mtd
->oobsize
;
459 ops
.mode
= MTD_OPS_PLACE_OOB
;
461 for (j
= 0; j
< numpages
; j
++) {
463 * Read the full oob until read_oob is fixed to handle single
464 * byte reads for 16 bit buswidth.
466 ret
= mtd_read_oob(mtd
, offs
, &ops
);
467 /* Ignore ECC errors when checking for BBM */
468 if (ret
&& !mtd_is_bitflip_or_eccerr(ret
))
471 if (check_short_pattern(buf
, bd
))
474 offs
+= mtd
->writesize
;
480 * create_bbt - [GENERIC] Create a bad block table by scanning the device
481 * @mtd: MTD device structure
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
487 * Create a bad block table by scanning the device for the given good/bad block
490 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
491 struct nand_bbt_descr
*bd
, int chip
)
493 struct nand_chip
*this = mtd
->priv
;
494 int i
, numblocks
, numpages
, scanlen
;
499 pr_info("Scanning device for bad blocks\n");
501 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
502 numpages
= 1 << (this->bbt_erase_shift
- this->page_shift
);
503 else if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
508 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
509 /* We need only read few bytes from the OOB area */
513 /* Full page content should be read */
514 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
515 readlen
= numpages
* mtd
->writesize
;
519 numblocks
= mtd
->size
>> this->bbt_erase_shift
;
523 if (chip
>= this->numchips
) {
524 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
525 chip
+ 1, this->numchips
);
528 numblocks
= this->chipsize
>> this->bbt_erase_shift
;
529 startblock
= chip
* numblocks
;
530 numblocks
+= startblock
;
531 from
= (loff_t
)startblock
<< this->bbt_erase_shift
;
534 if (this->bbt_options
& NAND_BBT_SCANLASTPAGE
)
535 from
+= mtd
->erasesize
- (mtd
->writesize
* numpages
);
537 for (i
= startblock
; i
< numblocks
; i
++) {
540 BUG_ON(bd
->options
& NAND_BBT_NO_OOB
);
542 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
543 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
546 ret
= scan_block_fast(mtd
, bd
, from
, buf
, numpages
);
552 bbt_mark_entry(this, i
, BBT_BLOCK_FACTORY_BAD
);
553 pr_warn("Bad eraseblock %d at 0x%012llx\n",
554 i
, (unsigned long long)from
);
555 mtd
->ecc_stats
.badblocks
++;
558 from
+= (1 << this->bbt_erase_shift
);
564 * search_bbt - [GENERIC] scan the device for a specific bad block table
565 * @mtd: MTD device structure
566 * @buf: temporary buffer
567 * @td: descriptor for the bad block table
569 * Read the bad block table by searching for a given ident pattern. Search is
570 * preformed either from the beginning up or from the end of the device
571 * downwards. The search starts always at the start of a block. If the option
572 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
573 * the bad block information of this chip. This is necessary to provide support
574 * for certain DOC devices.
576 * The bbt ident pattern resides in the oob area of the first page in a block.
578 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
580 struct nand_chip
*this = mtd
->priv
;
582 int bits
, startblock
, block
, dir
;
583 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
585 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
587 /* Search direction top -> down? */
588 if (td
->options
& NAND_BBT_LASTBLOCK
) {
589 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
596 /* Do we have a bbt per chip? */
597 if (td
->options
& NAND_BBT_PERCHIP
) {
598 chips
= this->numchips
;
599 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
600 startblock
&= bbtblocks
- 1;
603 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
606 /* Number of bits for each erase block in the bbt */
607 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
609 for (i
= 0; i
< chips
; i
++) {
610 /* Reset version information */
613 /* Scan the maximum number of blocks */
614 for (block
= 0; block
< td
->maxblocks
; block
++) {
616 int actblock
= startblock
+ dir
* block
;
617 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
619 /* Read first page */
620 scan_read(mtd
, buf
, offs
, mtd
->writesize
, td
);
621 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
622 td
->pages
[i
] = actblock
<< blocktopage
;
623 if (td
->options
& NAND_BBT_VERSION
) {
624 offs
= bbt_get_ver_offs(mtd
, td
);
625 td
->version
[i
] = buf
[offs
];
630 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
632 /* Check, if we found a bbt for each requested chip */
633 for (i
= 0; i
< chips
; i
++) {
634 if (td
->pages
[i
] == -1)
635 pr_warn("Bad block table not found for chip %d\n", i
);
637 pr_info("Bad block table found at page %d, version "
638 "0x%02X\n", td
->pages
[i
], td
->version
[i
]);
644 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
645 * @mtd: MTD device structure
646 * @buf: temporary buffer
647 * @td: descriptor for the bad block table
648 * @md: descriptor for the bad block table mirror
650 * Search and read the bad block table(s).
652 static void search_read_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
653 struct nand_bbt_descr
*td
,
654 struct nand_bbt_descr
*md
)
656 /* Search the primary table */
657 search_bbt(mtd
, buf
, td
);
659 /* Search the mirror table */
661 search_bbt(mtd
, buf
, md
);
665 * write_bbt - [GENERIC] (Re)write the bad block table
666 * @mtd: MTD device structure
667 * @buf: temporary buffer
668 * @td: descriptor for the bad block table
669 * @md: descriptor for the bad block table mirror
670 * @chipsel: selector for a specific chip, -1 for all
672 * (Re)write the bad block table.
674 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
675 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
678 struct nand_chip
*this = mtd
->priv
;
679 struct erase_info einfo
;
680 int i
, res
, chip
= 0;
681 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
682 int nrchips
, pageoffs
, ooboffs
;
684 uint8_t rcode
= td
->reserved_block_code
;
685 size_t retlen
, len
= 0;
687 struct mtd_oob_ops ops
;
689 ops
.ooblen
= mtd
->oobsize
;
692 ops
.mode
= MTD_OPS_PLACE_OOB
;
696 /* Write bad block table per chip rather than per device? */
697 if (td
->options
& NAND_BBT_PERCHIP
) {
698 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
699 /* Full device write or specific chip? */
701 nrchips
= this->numchips
;
703 nrchips
= chipsel
+ 1;
707 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
711 /* Loop through the chips */
712 for (; chip
< nrchips
; chip
++) {
714 * There was already a version of the table, reuse the page
715 * This applies for absolute placement too, as we have the
716 * page nr. in td->pages.
718 if (td
->pages
[chip
] != -1) {
719 page
= td
->pages
[chip
];
724 * Automatic placement of the bad block table. Search direction
727 if (td
->options
& NAND_BBT_LASTBLOCK
) {
728 startblock
= numblocks
* (chip
+ 1) - 1;
731 startblock
= chip
* numblocks
;
735 for (i
= 0; i
< td
->maxblocks
; i
++) {
736 int block
= startblock
+ dir
* i
;
737 /* Check, if the block is bad */
738 switch (bbt_get_entry(this, block
)) {
740 case BBT_BLOCK_FACTORY_BAD
:
744 (this->bbt_erase_shift
- this->page_shift
);
745 /* Check, if the block is used by the mirror table */
746 if (!md
|| md
->pages
[chip
] != page
)
749 pr_err("No space left to write bad block table\n");
753 /* Set up shift count and masks for the flash table */
754 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
757 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
760 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
763 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
766 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
769 default: return -EINVAL
;
772 to
= ((loff_t
)page
) << this->page_shift
;
774 /* Must we save the block contents? */
775 if (td
->options
& NAND_BBT_SAVECONTENT
) {
776 /* Make it block aligned */
777 to
&= ~((loff_t
)((1 << this->bbt_erase_shift
) - 1));
778 len
= 1 << this->bbt_erase_shift
;
779 res
= mtd_read(mtd
, to
, len
, &retlen
, buf
);
782 pr_info("nand_bbt: error reading block "
783 "for writing the bad block table\n");
786 pr_warn("nand_bbt: ECC error while reading "
787 "block for writing bad block table\n");
790 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
791 ops
.oobbuf
= &buf
[len
];
792 res
= mtd_read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
793 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
796 /* Calc the byte offset in the buffer */
797 pageoffs
= page
- (int)(to
>> this->page_shift
);
798 offs
= pageoffs
<< this->page_shift
;
799 /* Preset the bbt area with 0xff */
800 memset(&buf
[offs
], 0xff, (size_t)(numblocks
>> sft
));
801 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
803 } else if (td
->options
& NAND_BBT_NO_OOB
) {
806 /* The version byte */
807 if (td
->options
& NAND_BBT_VERSION
)
810 len
= (size_t)(numblocks
>> sft
);
812 /* Make it page aligned! */
813 len
= ALIGN(len
, mtd
->writesize
);
814 /* Preset the buffer with 0xff */
815 memset(buf
, 0xff, len
);
816 /* Pattern is located at the begin of first page */
817 memcpy(buf
, td
->pattern
, td
->len
);
820 len
= (size_t)(numblocks
>> sft
);
821 /* Make it page aligned! */
822 len
= ALIGN(len
, mtd
->writesize
);
823 /* Preset the buffer with 0xff */
824 memset(buf
, 0xff, len
+
825 (len
>> this->page_shift
)* mtd
->oobsize
);
828 /* Pattern is located in oob area of first page */
829 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
832 if (td
->options
& NAND_BBT_VERSION
)
833 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
835 /* Walk through the memory table */
836 for (i
= 0; i
< numblocks
; i
++) {
838 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
839 dat
= bbt_get_entry(this, chip
* numblocks
+ i
);
840 /* Do not store the reserved bbt blocks! */
841 buf
[offs
+ (i
>> sft
)] &= ~(msk
[dat
] << sftcnt
);
844 memset(&einfo
, 0, sizeof(einfo
));
847 einfo
.len
= 1 << this->bbt_erase_shift
;
848 res
= nand_erase_nand(mtd
, &einfo
, 1);
852 res
= scan_write_bbt(mtd
, to
, len
, buf
,
853 td
->options
& NAND_BBT_NO_OOB
? NULL
:
858 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
859 (unsigned long long)to
, td
->version
[chip
]);
861 /* Mark it as used */
862 td
->pages
[chip
] = page
;
867 pr_warn("nand_bbt: error while writing bad block table %d\n", res
);
872 * nand_memory_bbt - [GENERIC] create a memory based bad block table
873 * @mtd: MTD device structure
874 * @bd: descriptor for the good/bad block search pattern
876 * The function creates a memory based bbt by scanning the device for
877 * manufacturer / software marked good / bad blocks.
879 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
881 struct nand_chip
*this = mtd
->priv
;
883 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
884 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
888 * check_create - [GENERIC] create and write bbt(s) if necessary
889 * @mtd: MTD device structure
890 * @buf: temporary buffer
891 * @bd: descriptor for the good/bad block search pattern
893 * The function checks the results of the previous call to read_bbt and creates
894 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
895 * for the chip/device. Update is necessary if one of the tables is missing or
896 * the version nr. of one table is less than the other.
898 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
900 int i
, chips
, writeops
, create
, chipsel
, res
, res2
;
901 struct nand_chip
*this = mtd
->priv
;
902 struct nand_bbt_descr
*td
= this->bbt_td
;
903 struct nand_bbt_descr
*md
= this->bbt_md
;
904 struct nand_bbt_descr
*rd
, *rd2
;
906 /* Do we have a bbt per chip? */
907 if (td
->options
& NAND_BBT_PERCHIP
)
908 chips
= this->numchips
;
912 for (i
= 0; i
< chips
; i
++) {
918 /* Per chip or per device? */
919 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
920 /* Mirrored table available? */
922 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
925 } else if (td
->pages
[i
] == -1) {
928 } else if (md
->pages
[i
] == -1) {
931 } else if (td
->version
[i
] == md
->version
[i
]) {
933 if (!(td
->options
& NAND_BBT_VERSION
))
935 } else if (((int8_t)(td
->version
[i
] - md
->version
[i
])) > 0) {
943 if (td
->pages
[i
] == -1) {
952 /* Create the bad block table by scanning the device? */
953 if (!(td
->options
& NAND_BBT_CREATE
))
956 /* Create the table in memory by scanning the chip(s) */
957 if (!(this->bbt_options
& NAND_BBT_CREATE_EMPTY
))
958 create_bbt(mtd
, buf
, bd
, chipsel
);
965 /* Read back first? */
967 res
= read_abs_bbt(mtd
, buf
, rd
, chipsel
);
968 if (mtd_is_eccerr(res
)) {
969 /* Mark table as invalid */
976 /* If they weren't versioned, read both */
978 res2
= read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
979 if (mtd_is_eccerr(res2
)) {
980 /* Mark table as invalid */
988 /* Scrub the flash table(s)? */
989 if (mtd_is_bitflip(res
) || mtd_is_bitflip(res2
))
992 /* Update version numbers before writing */
994 td
->version
[i
] = max(td
->version
[i
], md
->version
[i
]);
995 md
->version
[i
] = td
->version
[i
];
998 /* Write the bad block table to the device? */
999 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1000 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1005 /* Write the mirror bad block table to the device? */
1006 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1007 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1016 * mark_bbt_regions - [GENERIC] mark the bad block table regions
1017 * @mtd: MTD device structure
1018 * @td: bad block table descriptor
1020 * The bad block table regions are marked as "bad" to prevent accidental
1021 * erasures / writes. The regions are identified by the mark 0x02.
1023 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
1025 struct nand_chip
*this = mtd
->priv
;
1026 int i
, j
, chips
, block
, nrblocks
, update
;
1029 /* Do we have a bbt per chip? */
1030 if (td
->options
& NAND_BBT_PERCHIP
) {
1031 chips
= this->numchips
;
1032 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
1035 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
1038 for (i
= 0; i
< chips
; i
++) {
1039 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
1040 !(td
->options
& NAND_BBT_WRITE
)) {
1041 if (td
->pages
[i
] == -1)
1043 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
1044 oldval
= bbt_get_entry(this, block
);
1045 bbt_mark_entry(this, block
, BBT_BLOCK_RESERVED
);
1046 if ((oldval
!= BBT_BLOCK_RESERVED
) &&
1047 td
->reserved_block_code
)
1048 nand_update_bbt(mtd
, (loff_t
)block
<<
1049 this->bbt_erase_shift
);
1053 if (td
->options
& NAND_BBT_LASTBLOCK
)
1054 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
1056 block
= i
* nrblocks
;
1057 for (j
= 0; j
< td
->maxblocks
; j
++) {
1058 oldval
= bbt_get_entry(this, block
);
1059 bbt_mark_entry(this, block
, BBT_BLOCK_RESERVED
);
1060 if (oldval
!= BBT_BLOCK_RESERVED
)
1065 * If we want reserved blocks to be recorded to flash, and some
1066 * new ones have been marked, then we need to update the stored
1067 * bbts. This should only happen once.
1069 if (update
&& td
->reserved_block_code
)
1070 nand_update_bbt(mtd
, (loff_t
)(block
- 1) <<
1071 this->bbt_erase_shift
);
1076 * verify_bbt_descr - verify the bad block description
1077 * @mtd: MTD device structure
1078 * @bd: the table to verify
1080 * This functions performs a few sanity checks on the bad block description
1083 static void verify_bbt_descr(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1085 struct nand_chip
*this = mtd
->priv
;
1093 pattern_len
= bd
->len
;
1094 bits
= bd
->options
& NAND_BBT_NRBITS_MSK
;
1096 BUG_ON((this->bbt_options
& NAND_BBT_NO_OOB
) &&
1097 !(this->bbt_options
& NAND_BBT_USE_FLASH
));
1100 if (bd
->options
& NAND_BBT_VERSION
)
1103 if (bd
->options
& NAND_BBT_NO_OOB
) {
1104 BUG_ON(!(this->bbt_options
& NAND_BBT_USE_FLASH
));
1105 BUG_ON(!(this->bbt_options
& NAND_BBT_NO_OOB
));
1107 if (bd
->options
& NAND_BBT_VERSION
)
1108 BUG_ON(bd
->veroffs
!= bd
->len
);
1109 BUG_ON(bd
->options
& NAND_BBT_SAVECONTENT
);
1112 if (bd
->options
& NAND_BBT_PERCHIP
)
1113 table_size
= this->chipsize
>> this->bbt_erase_shift
;
1115 table_size
= mtd
->size
>> this->bbt_erase_shift
;
1118 if (bd
->options
& NAND_BBT_NO_OOB
)
1119 table_size
+= pattern_len
;
1120 BUG_ON(table_size
> (1 << this->bbt_erase_shift
));
1124 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1125 * @mtd: MTD device structure
1126 * @bd: descriptor for the good/bad block search pattern
1128 * The function checks, if a bad block table(s) is/are already available. If
1129 * not it scans the device for manufacturer marked good / bad blocks and writes
1130 * the bad block table(s) to the selected place.
1132 * The bad block table memory is allocated here. It must be freed by calling
1133 * the nand_free_bbt function.
1135 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1137 struct nand_chip
*this = mtd
->priv
;
1140 struct nand_bbt_descr
*td
= this->bbt_td
;
1141 struct nand_bbt_descr
*md
= this->bbt_md
;
1143 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1145 * Allocate memory (2bit per block) and clear the memory bad block
1148 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1153 * If no primary table decriptor is given, scan the device to build a
1154 * memory based bad block table.
1157 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1158 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1164 verify_bbt_descr(mtd
, td
);
1165 verify_bbt_descr(mtd
, md
);
1167 /* Allocate a temporary buffer for one eraseblock incl. oob */
1168 len
= (1 << this->bbt_erase_shift
);
1169 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1177 /* Is the bbt at a given page? */
1178 if (td
->options
& NAND_BBT_ABSPAGE
) {
1179 read_abs_bbts(mtd
, buf
, td
, md
);
1181 /* Search the bad block table using a pattern in oob */
1182 search_read_bbts(mtd
, buf
, td
, md
);
1185 res
= check_create(mtd
, buf
, bd
);
1187 /* Prevent the bbt regions from erasing / writing */
1188 mark_bbt_region(mtd
, td
);
1190 mark_bbt_region(mtd
, md
);
1197 * nand_update_bbt - [NAND Interface] update bad block table(s)
1198 * @mtd: MTD device structure
1199 * @offs: the offset of the newly marked block
1201 * The function updates the bad block table(s).
1203 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1205 struct nand_chip
*this = mtd
->priv
;
1209 struct nand_bbt_descr
*td
= this->bbt_td
;
1210 struct nand_bbt_descr
*md
= this->bbt_md
;
1212 if (!this->bbt
|| !td
)
1215 /* Allocate a temporary buffer for one eraseblock incl. oob */
1216 len
= (1 << this->bbt_erase_shift
);
1217 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1218 buf
= kmalloc(len
, GFP_KERNEL
);
1222 /* Do we have a bbt per chip? */
1223 if (td
->options
& NAND_BBT_PERCHIP
) {
1224 chip
= (int)(offs
>> this->chip_shift
);
1231 td
->version
[chip
]++;
1233 md
->version
[chip
]++;
1235 /* Write the bad block table to the device? */
1236 if (td
->options
& NAND_BBT_WRITE
) {
1237 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1241 /* Write the mirror bad block table to the device? */
1242 if (md
&& (md
->options
& NAND_BBT_WRITE
)) {
1243 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1252 * Define some generic bad / good block scan pattern which are used
1253 * while scanning a device for factory marked good / bad blocks.
1255 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1257 /* Generic flash bbt descriptors */
1258 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1259 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1261 static struct nand_bbt_descr bbt_main_descr
= {
1262 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1263 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1267 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1268 .pattern
= bbt_pattern
1271 static struct nand_bbt_descr bbt_mirror_descr
= {
1272 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1273 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1277 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1278 .pattern
= mirror_pattern
1281 static struct nand_bbt_descr bbt_main_no_oob_descr
= {
1282 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1283 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1287 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1288 .pattern
= bbt_pattern
1291 static struct nand_bbt_descr bbt_mirror_no_oob_descr
= {
1292 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1293 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1297 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1298 .pattern
= mirror_pattern
1301 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1303 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1304 * @this: NAND chip to create descriptor for
1306 * This function allocates and initializes a nand_bbt_descr for BBM detection
1307 * based on the properties of @this. The new descriptor is stored in
1308 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1309 * passed to this function.
1311 static int nand_create_badblock_pattern(struct nand_chip
*this)
1313 struct nand_bbt_descr
*bd
;
1314 if (this->badblock_pattern
) {
1315 pr_warn("Bad block pattern already allocated; not replacing\n");
1318 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1321 bd
->options
= this->bbt_options
& BADBLOCK_SCAN_MASK
;
1322 bd
->offs
= this->badblockpos
;
1323 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1324 bd
->pattern
= scan_ff_pattern
;
1325 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1326 this->badblock_pattern
= bd
;
1331 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1332 * @mtd: MTD device structure
1334 * This function selects the default bad block table support for the device and
1335 * calls the nand_scan_bbt function.
1337 int nand_default_bbt(struct mtd_info
*mtd
)
1339 struct nand_chip
*this = mtd
->priv
;
1341 /* Is a flash based bad block table requested? */
1342 if (this->bbt_options
& NAND_BBT_USE_FLASH
) {
1343 /* Use the default pattern descriptors */
1344 if (!this->bbt_td
) {
1345 if (this->bbt_options
& NAND_BBT_NO_OOB
) {
1346 this->bbt_td
= &bbt_main_no_oob_descr
;
1347 this->bbt_md
= &bbt_mirror_no_oob_descr
;
1349 this->bbt_td
= &bbt_main_descr
;
1350 this->bbt_md
= &bbt_mirror_descr
;
1354 this->bbt_td
= NULL
;
1355 this->bbt_md
= NULL
;
1358 if (!this->badblock_pattern
)
1359 nand_create_badblock_pattern(this);
1361 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1365 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1366 * @mtd: MTD device structure
1367 * @offs: offset in the device
1368 * @allowbbt: allow access to bad block table region
1370 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1372 struct nand_chip
*this = mtd
->priv
;
1376 block
= (int)(offs
>> this->bbt_erase_shift
);
1377 res
= bbt_get_entry(this, block
);
1379 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: "
1380 "(block %d) 0x%02x\n",
1381 (unsigned int)offs
, block
, res
);
1384 case BBT_BLOCK_GOOD
:
1386 case BBT_BLOCK_WORN
:
1388 case BBT_BLOCK_RESERVED
:
1389 return allowbbt
? 0 : 1;
1394 EXPORT_SYMBOL(nand_scan_bbt
);
1395 EXPORT_SYMBOL(nand_default_bbt
);
1396 EXPORT_SYMBOL_GPL(nand_update_bbt
);