2 * drivers/mtd/nand_bbt.c
5 * Bad block table support for the NAND driver
7 * Copyright (C) 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 than 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27 * If one of the BBTs is out of date or does not exist it is (re)created.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/nand.h>
66 #include <linux/mtd/nand_ecc.h>
67 #include <linux/bitops.h>
68 #include <linux/delay.h>
69 #include <linux/vmalloc.h>
71 static int check_pattern_no_oob(uint8_t *buf
, struct nand_bbt_descr
*td
)
75 ret
= memcmp(buf
, td
->pattern
, td
->len
);
82 * check_pattern - [GENERIC] check if a pattern is in the buffer
83 * @buf: the buffer to search
84 * @len: the length of buffer to search
85 * @paglen: the pagelength
86 * @td: search pattern descriptor
88 * Check for a pattern at the given place. Used to search bad block tables and
89 * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if
90 * all bytes except the pattern area contain 0xff.
92 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
97 if (td
->options
& NAND_BBT_NO_OOB
)
98 return check_pattern_no_oob(buf
, td
);
100 end
= paglen
+ td
->offs
;
101 if (td
->options
& NAND_BBT_SCANEMPTY
) {
102 for (i
= 0; i
< end
; i
++) {
109 /* Compare the pattern */
110 for (i
= 0; i
< td
->len
; i
++) {
111 if (p
[i
] != td
->pattern
[i
])
115 if (td
->options
& NAND_BBT_SCANEMPTY
) {
118 for (i
= end
; i
< len
; i
++) {
127 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
128 * @buf: the buffer to search
129 * @td: search pattern descriptor
131 * Check for a pattern at the given place. Used to search bad block tables and
132 * good / bad block identifiers. Same as check_pattern, but no optional empty
135 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
140 /* Compare the pattern */
141 for (i
= 0; i
< td
->len
; i
++) {
142 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
149 * add_marker_len - compute the length of the marker in data area
150 * @td: BBT descriptor used for computation
152 * The length will be 0 if the marker is located in OOB area.
154 static u32
add_marker_len(struct nand_bbt_descr
*td
)
158 if (!(td
->options
& NAND_BBT_NO_OOB
))
162 if (td
->options
& NAND_BBT_VERSION
)
168 * read_bbt - [GENERIC] Read the bad block table starting from page
169 * @mtd: MTD device structure
170 * @buf: temporary buffer
171 * @page: the starting page
172 * @num: the number of bbt descriptors to read
173 * @td: the bbt describtion table
174 * @offs: offset in the memory table
176 * Read the bad block table starting from page.
178 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
179 struct nand_bbt_descr
*td
, int offs
)
181 int res
, i
, j
, act
= 0;
182 struct nand_chip
*this = mtd
->priv
;
183 size_t retlen
, len
, totlen
;
185 int bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
186 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
188 int reserved_block_code
= td
->reserved_block_code
;
190 totlen
= (num
* bits
) >> 3;
191 marker_len
= add_marker_len(td
);
192 from
= ((loff_t
) page
) << this->page_shift
;
195 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
198 * In case the BBT marker is not in the OOB area it
199 * will be just in the first page.
205 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
208 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
211 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
215 for (i
= 0; i
< len
; i
++) {
216 uint8_t dat
= buf
[i
];
217 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
218 uint8_t tmp
= (dat
>> j
) & msk
;
221 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
222 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
223 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
224 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
225 mtd
->ecc_stats
.bbtblocks
++;
229 * Leave it for now, if it's matured we can
230 * move this message to MTD_DEBUG_LEVEL0.
232 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%012llx\n",
233 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
234 /* Factory marked bad or worn out? */
236 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
238 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
239 mtd
->ecc_stats
.badblocks
++;
249 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
250 * @mtd: MTD device structure
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; aplies only if
254 * NAND_BBT_PERCHIP option is set
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.
259 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
261 struct nand_chip
*this = mtd
->priv
;
264 if (td
->options
& NAND_BBT_PERCHIP
) {
266 for (i
= 0; i
< this->numchips
; i
++) {
267 if (chip
== -1 || chip
== i
)
268 res
= read_bbt(mtd
, buf
, td
->pages
[i
],
269 this->chipsize
>> this->bbt_erase_shift
,
273 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
276 res
= read_bbt(mtd
, buf
, td
->pages
[0],
277 mtd
->size
>> this->bbt_erase_shift
, td
, 0);
284 /* BBT marker is in the first page, no OOB */
285 static int scan_read_raw_data(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
286 struct nand_bbt_descr
*td
)
292 if (td
->options
& NAND_BBT_VERSION
)
295 return mtd
->read(mtd
, offs
, len
, &retlen
, buf
);
298 /* Scan read raw data from flash */
299 static int scan_read_raw_oob(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
302 struct mtd_oob_ops ops
;
305 ops
.mode
= MTD_OOB_RAW
;
307 ops
.ooblen
= mtd
->oobsize
;
311 if (len
<= mtd
->writesize
) {
312 ops
.oobbuf
= buf
+ len
;
315 res
= mtd
->read_oob(mtd
, offs
, &ops
);
317 /* Ignore ECC errors when checking for BBM */
318 if (res
!= -EUCLEAN
&& res
!= -EBADMSG
)
322 ops
.oobbuf
= buf
+ mtd
->writesize
;
324 ops
.len
= mtd
->writesize
;
325 res
= mtd
->read_oob(mtd
, offs
, &ops
);
327 /* Ignore ECC errors when checking for BBM */
328 if (res
&& res
!= -EUCLEAN
&& res
!= -EBADMSG
)
332 buf
+= mtd
->oobsize
+ mtd
->writesize
;
333 len
-= mtd
->writesize
;
338 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
339 size_t len
, struct nand_bbt_descr
*td
)
341 if (td
->options
& NAND_BBT_NO_OOB
)
342 return scan_read_raw_data(mtd
, buf
, offs
, td
);
344 return scan_read_raw_oob(mtd
, buf
, offs
, len
);
347 /* Scan write data with oob to flash */
348 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
349 uint8_t *buf
, uint8_t *oob
)
351 struct mtd_oob_ops ops
;
353 ops
.mode
= MTD_OOB_PLACE
;
355 ops
.ooblen
= mtd
->oobsize
;
360 return mtd
->write_oob(mtd
, offs
, &ops
);
363 static u32
bbt_get_ver_offs(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
365 u32 ver_offs
= td
->veroffs
;
367 if (!(td
->options
& NAND_BBT_NO_OOB
))
368 ver_offs
+= mtd
->writesize
;
373 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
374 * @mtd: MTD device structure
375 * @buf: temporary buffer
376 * @td: descriptor for the bad block table
377 * @md: descriptor for the bad block table mirror
379 * Read the bad block table(s) for all chips starting at a given page. We
380 * assume that the bbt bits are in consecutive order.
382 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
383 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
385 struct nand_chip
*this = mtd
->priv
;
387 /* Read the primary version, if available */
388 if (td
->options
& NAND_BBT_VERSION
) {
389 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
391 td
->version
[0] = buf
[bbt_get_ver_offs(mtd
, td
)];
392 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
393 td
->pages
[0], td
->version
[0]);
396 /* Read the mirror version, if available */
397 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
398 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
400 md
->version
[0] = buf
[bbt_get_ver_offs(mtd
, md
)];
401 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
402 md
->pages
[0], md
->version
[0]);
407 /* Scan a given block full */
408 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
409 loff_t offs
, uint8_t *buf
, size_t readlen
,
410 int scanlen
, int len
)
414 ret
= scan_read_raw_oob(mtd
, buf
, offs
, readlen
);
418 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
419 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
425 /* Scan a given block partially */
426 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
427 loff_t offs
, uint8_t *buf
, int len
)
429 struct mtd_oob_ops ops
;
432 ops
.ooblen
= mtd
->oobsize
;
436 ops
.mode
= MTD_OOB_PLACE
;
438 for (j
= 0; j
< len
; j
++) {
440 * Read the full oob until read_oob is fixed to handle single
441 * byte reads for 16 bit buswidth.
443 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
444 /* Ignore ECC errors when checking for BBM */
445 if (ret
&& ret
!= -EUCLEAN
&& ret
!= -EBADMSG
)
448 if (check_short_pattern(buf
, bd
))
451 offs
+= mtd
->writesize
;
457 * create_bbt - [GENERIC] Create a bad block table by scanning the device
458 * @mtd: MTD device structure
459 * @buf: temporary buffer
460 * @bd: descriptor for the good/bad block search pattern
461 * @chip: create the table for a specific chip, -1 read all chips; applies only
462 * if NAND_BBT_PERCHIP option is set
464 * Create a bad block table by scanning the device for the given good/bad block
467 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
468 struct nand_bbt_descr
*bd
, int chip
)
470 struct nand_chip
*this = mtd
->priv
;
471 int i
, numblocks
, len
, scanlen
;
476 printk(KERN_INFO
"Scanning device for bad blocks\n");
478 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
479 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
480 else if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
485 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
486 /* We need only read few bytes from the OOB area */
490 /* Full page content should be read */
491 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
492 readlen
= len
* mtd
->writesize
;
497 * Note that numblocks is 2 * (real numblocks) here, see i+=2
498 * below as it makes shifting and masking less painful
500 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
504 if (chip
>= this->numchips
) {
505 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
506 chip
+ 1, this->numchips
);
509 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
510 startblock
= chip
* numblocks
;
511 numblocks
+= startblock
;
512 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
515 if (this->bbt_options
& NAND_BBT_SCANLASTPAGE
)
516 from
+= mtd
->erasesize
- (mtd
->writesize
* len
);
518 for (i
= startblock
; i
< numblocks
;) {
521 BUG_ON(bd
->options
& NAND_BBT_NO_OOB
);
523 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
524 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
527 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
533 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
534 printk(KERN_WARNING
"Bad eraseblock %d at 0x%012llx\n",
535 i
>> 1, (unsigned long long)from
);
536 mtd
->ecc_stats
.badblocks
++;
540 from
+= (1 << this->bbt_erase_shift
);
546 * search_bbt - [GENERIC] scan the device for a specific bad block table
547 * @mtd: MTD device structure
548 * @buf: temporary buffer
549 * @td: descriptor for the bad block table
551 * Read the bad block table by searching for a given ident pattern. Search is
552 * preformed either from the beginning up or from the end of the device
553 * downwards. The search starts always at the start of a block. If the option
554 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
555 * the bad block information of this chip. This is necessary to provide support
556 * for certain DOC devices.
558 * The bbt ident pattern resides in the oob area of the first page in a block.
560 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
562 struct nand_chip
*this = mtd
->priv
;
564 int bits
, startblock
, block
, dir
;
565 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
567 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
569 /* Search direction top -> down? */
570 if (td
->options
& NAND_BBT_LASTBLOCK
) {
571 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
578 /* Do we have a bbt per chip? */
579 if (td
->options
& NAND_BBT_PERCHIP
) {
580 chips
= this->numchips
;
581 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
582 startblock
&= bbtblocks
- 1;
585 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
588 /* Number of bits for each erase block in the bbt */
589 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
591 for (i
= 0; i
< chips
; i
++) {
592 /* Reset version information */
595 /* Scan the maximum number of blocks */
596 for (block
= 0; block
< td
->maxblocks
; block
++) {
598 int actblock
= startblock
+ dir
* block
;
599 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
601 /* Read first page */
602 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
, td
);
603 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
604 td
->pages
[i
] = actblock
<< blocktopage
;
605 if (td
->options
& NAND_BBT_VERSION
) {
606 offs
= bbt_get_ver_offs(mtd
, td
);
607 td
->version
[i
] = buf
[offs
];
612 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
614 /* Check, if we found a bbt for each requested chip */
615 for (i
= 0; i
< chips
; i
++) {
616 if (td
->pages
[i
] == -1)
617 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
619 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
626 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
627 * @mtd: MTD device structure
628 * @buf: temporary buffer
629 * @td: descriptor for the bad block table
630 * @md: descriptor for the bad block table mirror
632 * Search and read the bad block table(s).
634 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
636 /* Search the primary table */
637 search_bbt(mtd
, buf
, td
);
639 /* Search the mirror table */
641 search_bbt(mtd
, buf
, md
);
643 /* Force result check */
648 * write_bbt - [GENERIC] (Re)write the bad block table
649 * @mtd: MTD device structure
650 * @buf: temporary buffer
651 * @td: descriptor for the bad block table
652 * @md: descriptor for the bad block table mirror
653 * @chipsel: selector for a specific chip, -1 for all
655 * (Re)write the bad block table.
657 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
658 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
661 struct nand_chip
*this = mtd
->priv
;
662 struct erase_info einfo
;
663 int i
, j
, res
, chip
= 0;
664 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
665 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
667 uint8_t rcode
= td
->reserved_block_code
;
668 size_t retlen
, len
= 0;
670 struct mtd_oob_ops ops
;
672 ops
.ooblen
= mtd
->oobsize
;
675 ops
.mode
= MTD_OOB_PLACE
;
679 /* Write bad block table per chip rather than per device? */
680 if (td
->options
& NAND_BBT_PERCHIP
) {
681 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
682 /* Full device write or specific chip? */
684 nrchips
= this->numchips
;
686 nrchips
= chipsel
+ 1;
690 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
694 /* Loop through the chips */
695 for (; chip
< nrchips
; chip
++) {
697 * There was already a version of the table, reuse the page
698 * This applies for absolute placement too, as we have the
699 * page nr. in td->pages.
701 if (td
->pages
[chip
] != -1) {
702 page
= td
->pages
[chip
];
707 * Automatic placement of the bad block table. Search direction
710 if (td
->options
& NAND_BBT_LASTBLOCK
) {
711 startblock
= numblocks
* (chip
+ 1) - 1;
714 startblock
= chip
* numblocks
;
718 for (i
= 0; i
< td
->maxblocks
; i
++) {
719 int block
= startblock
+ dir
* i
;
720 /* Check, if the block is bad */
721 switch ((this->bbt
[block
>> 2] >>
722 (2 * (block
& 0x03))) & 0x03) {
728 (this->bbt_erase_shift
- this->page_shift
);
729 /* Check, if the block is used by the mirror table */
730 if (!md
|| md
->pages
[chip
] != page
)
733 printk(KERN_ERR
"No space left to write bad block table\n");
737 /* Set up shift count and masks for the flash table */
738 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
741 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
744 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
747 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
750 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
753 default: return -EINVAL
;
756 bbtoffs
= chip
* (numblocks
>> 2);
758 to
= ((loff_t
) page
) << this->page_shift
;
760 /* Must we save the block contents? */
761 if (td
->options
& NAND_BBT_SAVECONTENT
) {
762 /* Make it block aligned */
763 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
764 len
= 1 << this->bbt_erase_shift
;
765 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
768 printk(KERN_INFO
"nand_bbt: Error "
769 "reading block for writing "
770 "the bad block table\n");
773 printk(KERN_WARNING
"nand_bbt: ECC error "
774 "while reading block for writing "
775 "bad block table\n");
778 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
779 ops
.oobbuf
= &buf
[len
];
780 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
781 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
784 /* Calc the byte offset in the buffer */
785 pageoffs
= page
- (int)(to
>> this->page_shift
);
786 offs
= pageoffs
<< this->page_shift
;
787 /* Preset the bbt area with 0xff */
788 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
789 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
791 } else if (td
->options
& NAND_BBT_NO_OOB
) {
794 /* The version byte */
795 if (td
->options
& NAND_BBT_VERSION
)
798 len
= (size_t) (numblocks
>> sft
);
800 /* Make it page aligned! */
801 len
= ALIGN(len
, mtd
->writesize
);
802 /* Preset the buffer with 0xff */
803 memset(buf
, 0xff, len
);
804 /* Pattern is located at the begin of first page */
805 memcpy(buf
, td
->pattern
, td
->len
);
808 len
= (size_t) (numblocks
>> sft
);
809 /* Make it page aligned! */
810 len
= ALIGN(len
, mtd
->writesize
);
811 /* Preset the buffer with 0xff */
812 memset(buf
, 0xff, len
+
813 (len
>> this->page_shift
)* mtd
->oobsize
);
816 /* Pattern is located in oob area of first page */
817 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
820 if (td
->options
& NAND_BBT_VERSION
)
821 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
823 /* Walk through the memory table */
824 for (i
= 0; i
< numblocks
;) {
826 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
827 for (j
= 0; j
< 4; j
++, i
++) {
828 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
829 /* Do not store the reserved bbt blocks! */
830 buf
[offs
+ (i
>> sft
)] &=
831 ~(msk
[dat
& 0x03] << sftcnt
);
836 memset(&einfo
, 0, sizeof(einfo
));
839 einfo
.len
= 1 << this->bbt_erase_shift
;
840 res
= nand_erase_nand(mtd
, &einfo
, 1);
844 res
= scan_write_bbt(mtd
, to
, len
, buf
,
845 td
->options
& NAND_BBT_NO_OOB
? NULL
:
850 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, version "
851 "0x%02X\n", (unsigned long long)to
, td
->version
[chip
]);
853 /* Mark it as used */
854 td
->pages
[chip
] = page
;
860 "nand_bbt: Error while writing bad block table %d\n", res
);
865 * nand_memory_bbt - [GENERIC] create a memory based bad block table
866 * @mtd: MTD device structure
867 * @bd: descriptor for the good/bad block search pattern
869 * The function creates a memory based bbt by scanning the device for
870 * manufacturer / software marked good / bad blocks.
872 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
874 struct nand_chip
*this = mtd
->priv
;
876 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
877 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
881 * check_create - [GENERIC] create and write bbt(s) if necessary
882 * @mtd: MTD device structure
883 * @buf: temporary buffer
884 * @bd: descriptor for the good/bad block search pattern
886 * The function checks the results of the previous call to read_bbt and creates
887 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
888 * for the chip/device. Update is necessary if one of the tables is missing or
889 * the version nr. of one table is less than the other.
891 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
893 int i
, chips
, writeops
, chipsel
, res
;
894 struct nand_chip
*this = mtd
->priv
;
895 struct nand_bbt_descr
*td
= this->bbt_td
;
896 struct nand_bbt_descr
*md
= this->bbt_md
;
897 struct nand_bbt_descr
*rd
, *rd2
;
899 /* Do we have a bbt per chip? */
900 if (td
->options
& NAND_BBT_PERCHIP
)
901 chips
= this->numchips
;
905 for (i
= 0; i
< chips
; i
++) {
909 /* Per chip or per device? */
910 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
911 /* Mirrored table available? */
913 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
918 if (td
->pages
[i
] == -1) {
920 td
->version
[i
] = md
->version
[i
];
925 if (md
->pages
[i
] == -1) {
927 md
->version
[i
] = td
->version
[i
];
932 if (td
->version
[i
] == md
->version
[i
]) {
934 if (!(td
->options
& NAND_BBT_VERSION
))
939 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
941 md
->version
[i
] = td
->version
[i
];
945 td
->version
[i
] = md
->version
[i
];
952 if (td
->pages
[i
] == -1) {
960 /* Create the bad block table by scanning the device? */
961 if (!(td
->options
& NAND_BBT_CREATE
))
964 /* Create the table in memory by scanning the chip(s) */
965 if (!(this->bbt_options
& NAND_BBT_CREATE_EMPTY
))
966 create_bbt(mtd
, buf
, bd
, chipsel
);
972 /* Read back first? */
974 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
975 /* If they weren't versioned, read both */
977 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
979 /* Write the bad block table to the device? */
980 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
981 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
986 /* Write the mirror bad block table to the device? */
987 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
988 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
997 * mark_bbt_regions - [GENERIC] mark the bad block table regions
998 * @mtd: MTD device structure
999 * @td: bad block table descriptor
1001 * The bad block table regions are marked as "bad" to prevent accidental
1002 * erasures / writes. The regions are identified by the mark 0x02.
1004 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
1006 struct nand_chip
*this = mtd
->priv
;
1007 int i
, j
, chips
, block
, nrblocks
, update
;
1008 uint8_t oldval
, newval
;
1010 /* Do we have a bbt per chip? */
1011 if (td
->options
& NAND_BBT_PERCHIP
) {
1012 chips
= this->numchips
;
1013 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
1016 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
1019 for (i
= 0; i
< chips
; i
++) {
1020 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
1021 !(td
->options
& NAND_BBT_WRITE
)) {
1022 if (td
->pages
[i
] == -1)
1024 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
1026 oldval
= this->bbt
[(block
>> 3)];
1027 newval
= oldval
| (0x2 << (block
& 0x06));
1028 this->bbt
[(block
>> 3)] = newval
;
1029 if ((oldval
!= newval
) && td
->reserved_block_code
)
1030 nand_update_bbt(mtd
, (loff_t
)block
<< (this->bbt_erase_shift
- 1));
1034 if (td
->options
& NAND_BBT_LASTBLOCK
)
1035 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
1037 block
= i
* nrblocks
;
1039 for (j
= 0; j
< td
->maxblocks
; j
++) {
1040 oldval
= this->bbt
[(block
>> 3)];
1041 newval
= oldval
| (0x2 << (block
& 0x06));
1042 this->bbt
[(block
>> 3)] = newval
;
1043 if (oldval
!= newval
)
1048 * If we want reserved blocks to be recorded to flash, and some
1049 * new ones have been marked, then we need to update the stored
1050 * bbts. This should only happen once.
1052 if (update
&& td
->reserved_block_code
)
1053 nand_update_bbt(mtd
, (loff_t
)(block
- 2) << (this->bbt_erase_shift
- 1));
1058 * verify_bbt_descr - verify the bad block description
1059 * @mtd: MTD device structure
1060 * @bd: the table to verify
1062 * This functions performs a few sanity checks on the bad block description
1065 static void verify_bbt_descr(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1067 struct nand_chip
*this = mtd
->priv
;
1075 pattern_len
= bd
->len
;
1076 bits
= bd
->options
& NAND_BBT_NRBITS_MSK
;
1078 BUG_ON((this->bbt_options
& NAND_BBT_NO_OOB
) &&
1079 !(this->bbt_options
& NAND_BBT_USE_FLASH
));
1082 if (bd
->options
& NAND_BBT_VERSION
)
1085 if (bd
->options
& NAND_BBT_NO_OOB
) {
1086 BUG_ON(!(this->bbt_options
& NAND_BBT_USE_FLASH
));
1087 BUG_ON(!(this->bbt_options
& NAND_BBT_NO_OOB
));
1089 if (bd
->options
& NAND_BBT_VERSION
)
1090 BUG_ON(bd
->veroffs
!= bd
->len
);
1091 BUG_ON(bd
->options
& NAND_BBT_SAVECONTENT
);
1094 if (bd
->options
& NAND_BBT_PERCHIP
)
1095 table_size
= this->chipsize
>> this->bbt_erase_shift
;
1097 table_size
= mtd
->size
>> this->bbt_erase_shift
;
1100 if (bd
->options
& NAND_BBT_NO_OOB
)
1101 table_size
+= pattern_len
;
1102 BUG_ON(table_size
> (1 << this->bbt_erase_shift
));
1106 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1107 * @mtd: MTD device structure
1108 * @bd: descriptor for the good/bad block search pattern
1110 * The function checks, if a bad block table(s) is/are already available. If
1111 * not it scans the device for manufacturer marked good / bad blocks and writes
1112 * the bad block table(s) to the selected place.
1114 * The bad block table memory is allocated here. It must be freed by calling
1115 * the nand_free_bbt function.
1117 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1119 struct nand_chip
*this = mtd
->priv
;
1122 struct nand_bbt_descr
*td
= this->bbt_td
;
1123 struct nand_bbt_descr
*md
= this->bbt_md
;
1125 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1127 * Allocate memory (2bit per block) and clear the memory bad block
1130 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1135 * If no primary table decriptor is given, scan the device to build a
1136 * memory based bad block table.
1139 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1140 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1146 verify_bbt_descr(mtd
, td
);
1147 verify_bbt_descr(mtd
, md
);
1149 /* Allocate a temporary buffer for one eraseblock incl. oob */
1150 len
= (1 << this->bbt_erase_shift
);
1151 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1159 /* Is the bbt at a given page? */
1160 if (td
->options
& NAND_BBT_ABSPAGE
) {
1161 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1163 /* Search the bad block table using a pattern in oob */
1164 res
= search_read_bbts(mtd
, buf
, td
, md
);
1168 res
= check_create(mtd
, buf
, bd
);
1170 /* Prevent the bbt regions from erasing / writing */
1171 mark_bbt_region(mtd
, td
);
1173 mark_bbt_region(mtd
, md
);
1180 * nand_update_bbt - [NAND Interface] update bad block table(s)
1181 * @mtd: MTD device structure
1182 * @offs: the offset of the newly marked block
1184 * The function updates the bad block table(s).
1186 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1188 struct nand_chip
*this = mtd
->priv
;
1189 int len
, res
= 0, writeops
= 0;
1192 struct nand_bbt_descr
*td
= this->bbt_td
;
1193 struct nand_bbt_descr
*md
= this->bbt_md
;
1195 if (!this->bbt
|| !td
)
1198 /* Allocate a temporary buffer for one eraseblock incl. oob */
1199 len
= (1 << this->bbt_erase_shift
);
1200 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1201 buf
= kmalloc(len
, GFP_KERNEL
);
1205 writeops
= md
!= NULL
? 0x03 : 0x01;
1207 /* Do we have a bbt per chip? */
1208 if (td
->options
& NAND_BBT_PERCHIP
) {
1209 chip
= (int)(offs
>> this->chip_shift
);
1216 td
->version
[chip
]++;
1218 md
->version
[chip
]++;
1220 /* Write the bad block table to the device? */
1221 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1222 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1226 /* Write the mirror bad block table to the device? */
1227 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1228 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1237 * Define some generic bad / good block scan pattern which are used
1238 * while scanning a device for factory marked good / bad blocks.
1240 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1242 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1244 static struct nand_bbt_descr agand_flashbased
= {
1245 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1248 .pattern
= scan_agand_pattern
1251 /* Generic flash bbt descriptors */
1252 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1253 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1255 static struct nand_bbt_descr bbt_main_descr
= {
1256 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1257 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1262 .pattern
= bbt_pattern
1265 static struct nand_bbt_descr bbt_mirror_descr
= {
1266 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1267 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1272 .pattern
= mirror_pattern
1275 static struct nand_bbt_descr bbt_main_no_bbt_descr
= {
1276 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1277 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1282 .pattern
= bbt_pattern
1285 static struct nand_bbt_descr bbt_mirror_no_bbt_descr
= {
1286 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1287 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1292 .pattern
= mirror_pattern
1296 * nand_create_default_bbt_descr - [INTERN] Creates a BBT descriptor structure
1297 * @this: NAND chip to create descriptor for
1299 * This function allocates and initializes a nand_bbt_descr for BBM detection
1300 * based on the properties of "this". The new descriptor is stored in
1301 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1302 * passed to this function.
1304 static int nand_create_default_bbt_descr(struct nand_chip
*this)
1306 struct nand_bbt_descr
*bd
;
1307 if (this->badblock_pattern
) {
1308 printk(KERN_WARNING
"BBT descr already allocated; not replacing.\n");
1311 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1314 bd
->options
= this->bbt_options
;
1315 bd
->offs
= this->badblockpos
;
1316 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1317 bd
->pattern
= scan_ff_pattern
;
1318 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1319 this->badblock_pattern
= bd
;
1324 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1325 * @mtd: MTD device structure
1327 * This function selects the default bad block table support for the device and
1328 * calls the nand_scan_bbt function.
1330 int nand_default_bbt(struct mtd_info
*mtd
)
1332 struct nand_chip
*this = mtd
->priv
;
1335 * Default for AG-AND. We must use a flash based bad block table as the
1336 * devices have factory marked _good_ blocks. Erasing those blocks
1337 * leads to loss of the good / bad information, so we _must_ store this
1338 * information in a good / bad table during startup.
1340 if (this->options
& NAND_IS_AND
) {
1341 /* Use the default pattern descriptors */
1342 if (!this->bbt_td
) {
1343 this->bbt_td
= &bbt_main_descr
;
1344 this->bbt_md
= &bbt_mirror_descr
;
1346 this->bbt_options
|= NAND_BBT_USE_FLASH
;
1347 return nand_scan_bbt(mtd
, &agand_flashbased
);
1350 /* Is a flash based bad block table requested? */
1351 if (this->bbt_options
& NAND_BBT_USE_FLASH
) {
1352 /* Use the default pattern descriptors */
1353 if (!this->bbt_td
) {
1354 if (this->bbt_options
& NAND_BBT_NO_OOB
) {
1355 this->bbt_td
= &bbt_main_no_bbt_descr
;
1356 this->bbt_md
= &bbt_mirror_no_bbt_descr
;
1358 this->bbt_td
= &bbt_main_descr
;
1359 this->bbt_md
= &bbt_mirror_descr
;
1363 this->bbt_td
= NULL
;
1364 this->bbt_md
= NULL
;
1367 if (!this->badblock_pattern
)
1368 nand_create_default_bbt_descr(this);
1370 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1374 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1375 * @mtd: MTD device structure
1376 * @offs: offset in the device
1377 * @allowbbt: allow access to bad block table region
1379 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1381 struct nand_chip
*this = mtd
->priv
;
1385 /* Get block number * 2 */
1386 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1387 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1389 DEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1390 (unsigned int)offs
, block
>> 1, res
);
1398 return allowbbt
? 0 : 1;
1403 EXPORT_SYMBOL(nand_scan_bbt
);
1404 EXPORT_SYMBOL(nand_default_bbt
);