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 * $Id: nand_bbt.c,v 1.36 2005/11/07 11:14:30 gleixner Exp $
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
17 * When nand_scan_bbt is called, then it tries to find the bad block table
18 * depending on the options in the bbt descriptor(s). If a bbt is found
19 * then the contents are read and the memory based bbt is created. If a
20 * mirrored bbt is selected then the mirror is searched too and the
21 * versions are compared. If the mirror has a greater version number
22 * than the mirror bbt is used to build the memory based bbt.
23 * If the tables are not versioned, then we "or" the bad block information.
24 * If one of the bbt's is out of date or does not exist it is (re)created.
25 * If no bbt exists at all then the device is scanned for factory marked
26 * good / bad blocks and the bad block tables are created.
28 * For manufacturer created bbts like the one found on M-SYS DOC devices
29 * the bbt is searched and read but never created
31 * The autogenerated bad block table is located in the last good blocks
32 * of the device. The table is mirrored, so it can be updated eventually.
33 * The table is marked in the oob area with an ident pattern and a version
34 * number which indicates which of both tables is more up to date.
36 * The table uses 2 bits per block
38 * 00b: block is factory marked bad
39 * 01b, 10b: block is marked bad due to wear
41 * The memory bad block table uses the following scheme:
43 * 01b: block is marked bad due to wear
44 * 10b: block is reserved (to protect the bbt area)
45 * 11b: block is factory marked bad
47 * Multichip devices like DOC store the bad block info per floor.
49 * Following assumptions are made:
50 * - bbts start at a page boundary, if autolocated on a block boundary
51 * - the space necessary for a bbt in FLASH does not exceed a block boundary
55 #include <linux/types.h>
56 #include <linux/mtd/mtd.h>
57 #include <linux/mtd/nand.h>
58 #include <linux/mtd/nand_ecc.h>
59 #include <linux/bitops.h>
64 #ifndef DOXYGEN_SHOULD_SKIP_THIS
67 * check_pattern - [GENERIC] check if a pattern is in the buffer
68 * @buf: the buffer to search
69 * @len: the length of buffer to search
70 * @paglen: the pagelength
71 * @td: search pattern descriptor
73 * Check for a pattern at the given place. Used to search bad block
74 * tables and good / bad block identifiers.
75 * If the SCAN_EMPTY option is set then check, if all bytes except the
76 * pattern area contain 0xff
79 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
84 end
= paglen
+ td
->offs
;
85 if (td
->options
& NAND_BBT_SCANEMPTY
) {
86 for (i
= 0; i
< end
; i
++) {
93 /* Compare the pattern */
94 for (i
= 0; i
< td
->len
; i
++) {
95 if (p
[i
] != td
->pattern
[i
])
99 if (td
->options
& NAND_BBT_SCANEMPTY
) {
102 for (i
= end
; i
< len
; i
++) {
111 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
112 * @buf: the buffer to search
113 * @td: search pattern descriptor
115 * Check for a pattern at the given place. Used to search bad block
116 * tables and good / bad block identifiers. Same as check_pattern, but
117 * no optional empty check
120 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
125 /* Compare the pattern */
126 for (i
= 0; i
< td
->len
; i
++) {
127 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
134 * read_bbt - [GENERIC] Read the bad block table starting from page
135 * @mtd: MTD device structure
136 * @buf: temporary buffer
137 * @page: the starting page
138 * @num: the number of bbt descriptors to read
139 * @bits: number of bits per block
140 * @offs: offset in the memory table
141 * @reserved_block_code: Pattern to identify reserved blocks
143 * Read the bad block table starting from page.
146 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
147 int bits
, int offs
, int reserved_block_code
)
149 int res
, i
, j
, act
= 0;
150 struct nand_chip
*this = mtd
->priv
;
151 size_t retlen
, len
, totlen
;
153 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
155 totlen
= (num
* bits
) >> 3;
156 from
= ((loff_t
) page
) << this->page_shift
;
159 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
160 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
163 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
166 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
170 for (i
= 0; i
< len
; i
++) {
171 uint8_t dat
= buf
[i
];
172 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
173 uint8_t tmp
= (dat
>> j
) & msk
;
176 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
177 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%08x\n",
178 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
179 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
180 mtd
->ecc_stats
.bbtblocks
++;
183 /* Leave it for now, if its matured we can move this
184 * message to MTD_DEBUG_LEVEL0 */
185 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%08x\n",
186 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
187 /* Factory marked bad or worn out ? */
189 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
191 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
192 mtd
->ecc_stats
.badblocks
++;
202 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
203 * @mtd: MTD device structure
204 * @buf: temporary buffer
205 * @td: descriptor for the bad block table
206 * @chip: read the table for a specific chip, -1 read all chips.
207 * Applies only if NAND_BBT_PERCHIP option is set
209 * Read the bad block table for all chips starting at a given page
210 * We assume that the bbt bits are in consecutive order.
212 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
214 struct nand_chip
*this = mtd
->priv
;
218 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
219 if (td
->options
& NAND_BBT_PERCHIP
) {
221 for (i
= 0; i
< this->numchips
; i
++) {
222 if (chip
== -1 || chip
== i
)
223 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
226 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
229 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
237 * Scan read raw data from flash
239 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
242 struct mtd_oob_ops ops
;
244 ops
.mode
= MTD_OOB_RAW
;
246 ops
.ooblen
= mtd
->oobsize
;
251 return mtd
->read_oob(mtd
, offs
, &ops
);
255 * Scan write data with oob to flash
257 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
258 uint8_t *buf
, uint8_t *oob
)
260 struct mtd_oob_ops ops
;
262 ops
.mode
= MTD_OOB_PLACE
;
264 ops
.ooblen
= mtd
->oobsize
;
269 return mtd
->write_oob(mtd
, offs
, &ops
);
273 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
274 * @mtd: MTD device structure
275 * @buf: temporary buffer
276 * @td: descriptor for the bad block table
277 * @md: descriptor for the bad block table mirror
279 * Read the bad block table(s) for all chips starting at a given page
280 * We assume that the bbt bits are in consecutive order.
283 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
284 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
286 struct nand_chip
*this = mtd
->priv
;
288 /* Read the primary version, if available */
289 if (td
->options
& NAND_BBT_VERSION
) {
290 scan_read_raw(mtd
, buf
, td
->pages
[0] << this->page_shift
,
292 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
293 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
294 td
->pages
[0], td
->version
[0]);
297 /* Read the mirror version, if available */
298 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
299 scan_read_raw(mtd
, buf
, md
->pages
[0] << this->page_shift
,
301 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
302 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
303 md
->pages
[0], md
->version
[0]);
309 * Scan a given block full
311 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
312 loff_t offs
, uint8_t *buf
, size_t readlen
,
313 int scanlen
, int len
)
317 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
321 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
322 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
329 * Scan a given block partially
331 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
332 loff_t offs
, uint8_t *buf
, int len
)
334 struct mtd_oob_ops ops
;
337 ops
.ooblen
= mtd
->oobsize
;
341 ops
.mode
= MTD_OOB_PLACE
;
343 for (j
= 0; j
< len
; j
++) {
345 * Read the full oob until read_oob is fixed to
346 * handle single byte reads for 16 bit
349 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
353 if (check_short_pattern(buf
, bd
))
356 offs
+= mtd
->writesize
;
362 * create_bbt - [GENERIC] Create a bad block table by scanning the device
363 * @mtd: MTD device structure
364 * @buf: temporary buffer
365 * @bd: descriptor for the good/bad block search pattern
366 * @chip: create the table for a specific chip, -1 read all chips.
367 * Applies only if NAND_BBT_PERCHIP option is set
369 * Create a bad block table by scanning the device
370 * for the given good/bad block identify pattern
372 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
373 struct nand_bbt_descr
*bd
, int chip
)
375 struct nand_chip
*this = mtd
->priv
;
376 int i
, numblocks
, len
, scanlen
;
381 printk(KERN_INFO
"Scanning device for bad blocks\n");
383 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
384 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
386 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
392 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
393 /* We need only read few bytes from the OOB area */
397 /* Full page content should be read */
398 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
399 readlen
= len
* mtd
->writesize
;
403 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
404 * below as it makes shifting and masking less painful */
405 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
409 if (chip
>= this->numchips
) {
410 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
411 chip
+ 1, this->numchips
);
414 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
415 startblock
= chip
* numblocks
;
416 numblocks
+= startblock
;
417 from
= startblock
<< (this->bbt_erase_shift
- 1);
420 for (i
= startblock
; i
< numblocks
;) {
423 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
424 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
427 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
433 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
434 printk(KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
435 i
>> 1, (unsigned int)from
);
436 mtd
->ecc_stats
.badblocks
++;
440 from
+= (1 << this->bbt_erase_shift
);
446 * search_bbt - [GENERIC] scan the device for a specific bad block table
447 * @mtd: MTD device structure
448 * @buf: temporary buffer
449 * @td: descriptor for the bad block table
451 * Read the bad block table by searching for a given ident pattern.
452 * Search is preformed either from the beginning up or from the end of
453 * the device downwards. The search starts always at the start of a
455 * If the option NAND_BBT_PERCHIP is given, each chip is searched
456 * for a bbt, which contains the bad block information of this chip.
457 * This is necessary to provide support for certain DOC devices.
459 * The bbt ident pattern resides in the oob area of the first page
462 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
464 struct nand_chip
*this = mtd
->priv
;
466 int bits
, startblock
, block
, dir
;
467 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
469 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
471 /* Search direction top -> down ? */
472 if (td
->options
& NAND_BBT_LASTBLOCK
) {
473 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
480 /* Do we have a bbt per chip ? */
481 if (td
->options
& NAND_BBT_PERCHIP
) {
482 chips
= this->numchips
;
483 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
484 startblock
&= bbtblocks
- 1;
487 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
490 /* Number of bits for each erase block in the bbt */
491 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
493 for (i
= 0; i
< chips
; i
++) {
494 /* Reset version information */
497 /* Scan the maximum number of blocks */
498 for (block
= 0; block
< td
->maxblocks
; block
++) {
500 int actblock
= startblock
+ dir
* block
;
501 loff_t offs
= actblock
<< this->bbt_erase_shift
;
503 /* Read first page */
504 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
505 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
506 td
->pages
[i
] = actblock
<< blocktopage
;
507 if (td
->options
& NAND_BBT_VERSION
) {
508 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
513 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
515 /* Check, if we found a bbt for each requested chip */
516 for (i
= 0; i
< chips
; i
++) {
517 if (td
->pages
[i
] == -1)
518 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
520 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
527 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
528 * @mtd: MTD device structure
529 * @buf: temporary buffer
530 * @td: descriptor for the bad block table
531 * @md: descriptor for the bad block table mirror
533 * Search and read the bad block table(s)
535 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
537 /* Search the primary table */
538 search_bbt(mtd
, buf
, td
);
540 /* Search the mirror table */
542 search_bbt(mtd
, buf
, md
);
544 /* Force result check */
549 * write_bbt - [GENERIC] (Re)write the bad block table
551 * @mtd: MTD device structure
552 * @buf: temporary buffer
553 * @td: descriptor for the bad block table
554 * @md: descriptor for the bad block table mirror
555 * @chipsel: selector for a specific chip, -1 for all
557 * (Re)write the bad block table
560 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
561 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
564 struct nand_chip
*this = mtd
->priv
;
565 struct erase_info einfo
;
566 int i
, j
, res
, chip
= 0;
567 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
568 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
570 uint8_t rcode
= td
->reserved_block_code
;
571 size_t retlen
, len
= 0;
573 struct mtd_oob_ops ops
;
575 ops
.ooblen
= mtd
->oobsize
;
578 ops
.mode
= MTD_OOB_PLACE
;
582 /* Write bad block table per chip rather than per device ? */
583 if (td
->options
& NAND_BBT_PERCHIP
) {
584 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
585 /* Full device write or specific chip ? */
587 nrchips
= this->numchips
;
589 nrchips
= chipsel
+ 1;
593 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
597 /* Loop through the chips */
598 for (; chip
< nrchips
; chip
++) {
600 /* There was already a version of the table, reuse the page
601 * This applies for absolute placement too, as we have the
602 * page nr. in td->pages.
604 if (td
->pages
[chip
] != -1) {
605 page
= td
->pages
[chip
];
609 /* Automatic placement of the bad block table */
610 /* Search direction top -> down ? */
611 if (td
->options
& NAND_BBT_LASTBLOCK
) {
612 startblock
= numblocks
* (chip
+ 1) - 1;
615 startblock
= chip
* numblocks
;
619 for (i
= 0; i
< td
->maxblocks
; i
++) {
620 int block
= startblock
+ dir
* i
;
621 /* Check, if the block is bad */
622 switch ((this->bbt
[block
>> 2] >>
623 (2 * (block
& 0x03))) & 0x03) {
629 (this->bbt_erase_shift
- this->page_shift
);
630 /* Check, if the block is used by the mirror table */
631 if (!md
|| md
->pages
[chip
] != page
)
634 printk(KERN_ERR
"No space left to write bad block table\n");
638 /* Set up shift count and masks for the flash table */
639 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
642 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
645 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
648 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
651 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
654 default: return -EINVAL
;
657 bbtoffs
= chip
* (numblocks
>> 2);
659 to
= ((loff_t
) page
) << this->page_shift
;
661 /* Must we save the block contents ? */
662 if (td
->options
& NAND_BBT_SAVECONTENT
) {
663 /* Make it block aligned */
664 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
665 len
= 1 << this->bbt_erase_shift
;
666 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
669 printk(KERN_INFO
"nand_bbt: Error "
670 "reading block for writing "
671 "the bad block table\n");
674 printk(KERN_WARNING
"nand_bbt: ECC error "
675 "while reading block for writing "
676 "bad block table\n");
679 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
680 ops
.oobbuf
= &buf
[len
];
681 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
682 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
685 /* Calc the byte offset in the buffer */
686 pageoffs
= page
- (int)(to
>> this->page_shift
);
687 offs
= pageoffs
<< this->page_shift
;
688 /* Preset the bbt area with 0xff */
689 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
690 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
694 len
= (size_t) (numblocks
>> sft
);
695 /* Make it page aligned ! */
696 len
= (len
+ (mtd
->writesize
- 1)) &
697 ~(mtd
->writesize
- 1);
698 /* Preset the buffer with 0xff */
699 memset(buf
, 0xff, len
+
700 (len
>> this->page_shift
)* mtd
->oobsize
);
703 /* Pattern is located in oob area of first page */
704 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
707 if (td
->options
& NAND_BBT_VERSION
)
708 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
710 /* walk through the memory table */
711 for (i
= 0; i
< numblocks
;) {
713 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
714 for (j
= 0; j
< 4; j
++, i
++) {
715 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
716 /* Do not store the reserved bbt blocks ! */
717 buf
[offs
+ (i
>> sft
)] &=
718 ~(msk
[dat
& 0x03] << sftcnt
);
723 memset(&einfo
, 0, sizeof(einfo
));
725 einfo
.addr
= (unsigned long)to
;
726 einfo
.len
= 1 << this->bbt_erase_shift
;
727 res
= nand_erase_nand(mtd
, &einfo
, 1);
731 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
735 printk(KERN_DEBUG
"Bad block table written to 0x%08x, version "
736 "0x%02X\n", (unsigned int)to
, td
->version
[chip
]);
738 /* Mark it as used */
739 td
->pages
[chip
] = page
;
745 "nand_bbt: Error while writing bad block table %d\n", res
);
750 * nand_memory_bbt - [GENERIC] create a memory based bad block table
751 * @mtd: MTD device structure
752 * @bd: descriptor for the good/bad block search pattern
754 * The function creates a memory based bbt by scanning the device
755 * for manufacturer / software marked good / bad blocks
757 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
759 struct nand_chip
*this = mtd
->priv
;
761 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
762 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
766 * check_create - [GENERIC] create and write bbt(s) if necessary
767 * @mtd: MTD device structure
768 * @buf: temporary buffer
769 * @bd: descriptor for the good/bad block search pattern
771 * The function checks the results of the previous call to read_bbt
772 * and creates / updates the bbt(s) if necessary
773 * Creation is necessary if no bbt was found for the chip/device
774 * Update is necessary if one of the tables is missing or the
775 * version nr. of one table is less than the other
777 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
779 int i
, chips
, writeops
, chipsel
, res
;
780 struct nand_chip
*this = mtd
->priv
;
781 struct nand_bbt_descr
*td
= this->bbt_td
;
782 struct nand_bbt_descr
*md
= this->bbt_md
;
783 struct nand_bbt_descr
*rd
, *rd2
;
785 /* Do we have a bbt per chip ? */
786 if (td
->options
& NAND_BBT_PERCHIP
)
787 chips
= this->numchips
;
791 for (i
= 0; i
< chips
; i
++) {
795 /* Per chip or per device ? */
796 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
797 /* Mirrored table avilable ? */
799 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
804 if (td
->pages
[i
] == -1) {
806 td
->version
[i
] = md
->version
[i
];
811 if (md
->pages
[i
] == -1) {
813 md
->version
[i
] = td
->version
[i
];
818 if (td
->version
[i
] == md
->version
[i
]) {
820 if (!(td
->options
& NAND_BBT_VERSION
))
825 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
827 md
->version
[i
] = td
->version
[i
];
831 td
->version
[i
] = md
->version
[i
];
838 if (td
->pages
[i
] == -1) {
846 /* Create the bad block table by scanning the device ? */
847 if (!(td
->options
& NAND_BBT_CREATE
))
850 /* Create the table in memory by scanning the chip(s) */
851 create_bbt(mtd
, buf
, bd
, chipsel
);
857 /* read back first ? */
859 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
860 /* If they weren't versioned, read both. */
862 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
864 /* Write the bad block table to the device ? */
865 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
866 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
871 /* Write the mirror bad block table to the device ? */
872 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
873 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
882 * mark_bbt_regions - [GENERIC] mark the bad block table regions
883 * @mtd: MTD device structure
884 * @td: bad block table descriptor
886 * The bad block table regions are marked as "bad" to prevent
887 * accidental erasures / writes. The regions are identified by
890 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
892 struct nand_chip
*this = mtd
->priv
;
893 int i
, j
, chips
, block
, nrblocks
, update
;
894 uint8_t oldval
, newval
;
896 /* Do we have a bbt per chip ? */
897 if (td
->options
& NAND_BBT_PERCHIP
) {
898 chips
= this->numchips
;
899 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
902 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
905 for (i
= 0; i
< chips
; i
++) {
906 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
907 !(td
->options
& NAND_BBT_WRITE
)) {
908 if (td
->pages
[i
] == -1)
910 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
912 oldval
= this->bbt
[(block
>> 3)];
913 newval
= oldval
| (0x2 << (block
& 0x06));
914 this->bbt
[(block
>> 3)] = newval
;
915 if ((oldval
!= newval
) && td
->reserved_block_code
)
916 nand_update_bbt(mtd
, block
<< (this->bbt_erase_shift
- 1));
920 if (td
->options
& NAND_BBT_LASTBLOCK
)
921 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
923 block
= i
* nrblocks
;
925 for (j
= 0; j
< td
->maxblocks
; j
++) {
926 oldval
= this->bbt
[(block
>> 3)];
927 newval
= oldval
| (0x2 << (block
& 0x06));
928 this->bbt
[(block
>> 3)] = newval
;
929 if (oldval
!= newval
)
933 /* If we want reserved blocks to be recorded to flash, and some
934 new ones have been marked, then we need to update the stored
935 bbts. This should only happen once. */
936 if (update
&& td
->reserved_block_code
)
937 nand_update_bbt(mtd
, (block
- 2) << (this->bbt_erase_shift
- 1));
942 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
943 * @mtd: MTD device structure
944 * @bd: descriptor for the good/bad block search pattern
946 * The function checks, if a bad block table(s) is/are already
947 * available. If not it scans the device for manufacturer
948 * marked good / bad blocks and writes the bad block table(s) to
949 * the selected place.
951 * The bad block table memory is allocated here. It must be freed
952 * by calling the nand_free_bbt function.
955 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
957 struct nand_chip
*this = mtd
->priv
;
960 struct nand_bbt_descr
*td
= this->bbt_td
;
961 struct nand_bbt_descr
*md
= this->bbt_md
;
963 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
964 /* Allocate memory (2bit per block) and clear the memory bad block table */
965 this->bbt
= kzalloc(len
, GFP_KERNEL
);
967 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
971 /* If no primary table decriptor is given, scan the device
972 * to build a memory based bad block table
975 if ((res
= nand_memory_bbt(mtd
, bd
))) {
976 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
983 /* Allocate a temporary buffer for one eraseblock incl. oob */
984 len
= (1 << this->bbt_erase_shift
);
985 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
988 printk(KERN_ERR
"nand_bbt: Out of memory\n");
994 /* Is the bbt at a given page ? */
995 if (td
->options
& NAND_BBT_ABSPAGE
) {
996 res
= read_abs_bbts(mtd
, buf
, td
, md
);
998 /* Search the bad block table using a pattern in oob */
999 res
= search_read_bbts(mtd
, buf
, td
, md
);
1003 res
= check_create(mtd
, buf
, bd
);
1005 /* Prevent the bbt regions from erasing / writing */
1006 mark_bbt_region(mtd
, td
);
1008 mark_bbt_region(mtd
, md
);
1015 * nand_update_bbt - [NAND Interface] update bad block table(s)
1016 * @mtd: MTD device structure
1017 * @offs: the offset of the newly marked block
1019 * The function updates the bad block table(s)
1021 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1023 struct nand_chip
*this = mtd
->priv
;
1024 int len
, res
= 0, writeops
= 0;
1027 struct nand_bbt_descr
*td
= this->bbt_td
;
1028 struct nand_bbt_descr
*md
= this->bbt_md
;
1030 if (!this->bbt
|| !td
)
1033 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1034 /* Allocate a temporary buffer for one eraseblock incl. oob */
1035 len
= (1 << this->bbt_erase_shift
);
1036 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1037 buf
= kmalloc(len
, GFP_KERNEL
);
1039 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1043 writeops
= md
!= NULL
? 0x03 : 0x01;
1045 /* Do we have a bbt per chip ? */
1046 if (td
->options
& NAND_BBT_PERCHIP
) {
1047 chip
= (int)(offs
>> this->chip_shift
);
1054 td
->version
[chip
]++;
1056 md
->version
[chip
]++;
1058 /* Write the bad block table to the device ? */
1059 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1060 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1064 /* Write the mirror bad block table to the device ? */
1065 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1066 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1074 /* Define some generic bad / good block scan pattern which are used
1075 * while scanning a device for factory marked good / bad blocks. */
1076 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1078 static struct nand_bbt_descr smallpage_memorybased
= {
1079 .options
= NAND_BBT_SCAN2NDPAGE
,
1082 .pattern
= scan_ff_pattern
1085 static struct nand_bbt_descr largepage_memorybased
= {
1089 .pattern
= scan_ff_pattern
1092 static struct nand_bbt_descr smallpage_flashbased
= {
1093 .options
= NAND_BBT_SCAN2NDPAGE
,
1096 .pattern
= scan_ff_pattern
1099 static struct nand_bbt_descr largepage_flashbased
= {
1100 .options
= NAND_BBT_SCAN2NDPAGE
,
1103 .pattern
= scan_ff_pattern
1106 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1108 static struct nand_bbt_descr agand_flashbased
= {
1109 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1112 .pattern
= scan_agand_pattern
1115 /* Generic flash bbt decriptors
1117 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1118 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1120 static struct nand_bbt_descr bbt_main_descr
= {
1121 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1122 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1127 .pattern
= bbt_pattern
1130 static struct nand_bbt_descr bbt_mirror_descr
= {
1131 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1132 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1137 .pattern
= mirror_pattern
1141 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1142 * @mtd: MTD device structure
1144 * This function selects the default bad block table
1145 * support for the device and calls the nand_scan_bbt function
1148 int nand_default_bbt(struct mtd_info
*mtd
)
1150 struct nand_chip
*this = mtd
->priv
;
1152 /* Default for AG-AND. We must use a flash based
1153 * bad block table as the devices have factory marked
1154 * _good_ blocks. Erasing those blocks leads to loss
1155 * of the good / bad information, so we _must_ store
1156 * this information in a good / bad table during
1159 if (this->options
& NAND_IS_AND
) {
1160 /* Use the default pattern descriptors */
1161 if (!this->bbt_td
) {
1162 this->bbt_td
= &bbt_main_descr
;
1163 this->bbt_md
= &bbt_mirror_descr
;
1165 this->options
|= NAND_USE_FLASH_BBT
;
1166 return nand_scan_bbt(mtd
, &agand_flashbased
);
1169 /* Is a flash based bad block table requested ? */
1170 if (this->options
& NAND_USE_FLASH_BBT
) {
1171 /* Use the default pattern descriptors */
1172 if (!this->bbt_td
) {
1173 this->bbt_td
= &bbt_main_descr
;
1174 this->bbt_md
= &bbt_mirror_descr
;
1176 if (!this->badblock_pattern
) {
1177 this->badblock_pattern
= (mtd
->writesize
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1180 this->bbt_td
= NULL
;
1181 this->bbt_md
= NULL
;
1182 if (!this->badblock_pattern
) {
1183 this->badblock_pattern
= (mtd
->writesize
> 512) ?
1184 &largepage_memorybased
: &smallpage_memorybased
;
1187 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1191 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1192 * @mtd: MTD device structure
1193 * @offs: offset in the device
1194 * @allowbbt: allow access to bad block table region
1197 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1199 struct nand_chip
*this = mtd
->priv
;
1203 /* Get block number * 2 */
1204 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1205 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1207 MTD_DEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1208 (unsigned int)offs
, block
>> 1, res
);
1216 return allowbbt
? 0 : 1;
1221 EXPORT_SYMBOL(nand_scan_bbt
);
1222 EXPORT_SYMBOL(nand_default_bbt
);
1224 #endif /* DOXYGEN_SHOULD_SKIP_THIS */