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 a bbt is found
17 * then the contents are read and the memory based bbt is created. If a
18 * mirrored bbt is selected then the mirror is searched too and the
19 * versions are compared. If the mirror has a greater version number
20 * than the mirror bbt is used to build the memory based bbt.
21 * If the tables are not versioned, then we "or" the bad block information.
22 * If one of the bbt's is out of date or does not exist it is (re)created.
23 * If no bbt exists at all then the device is scanned for factory marked
24 * good / bad blocks and the bad block tables are created.
26 * For manufacturer created bbts like the one found on M-SYS DOC devices
27 * the bbt is searched and read but never created
29 * The autogenerated bad block table is located in the last good blocks
30 * of the device. The table is mirrored, so it can be updated eventually.
31 * The table is marked in the oob area with an ident pattern and a version
32 * number which indicates which of both tables is more up to date.
34 * The table uses 2 bits per block
36 * 00b: block is factory marked bad
37 * 01b, 10b: block is marked bad due to wear
39 * The memory bad block table uses the following scheme:
41 * 01b: block is marked bad due to wear
42 * 10b: block is reserved (to protect the bbt area)
43 * 11b: block is factory marked bad
45 * Multichip devices like DOC store the bad block info per floor.
47 * Following assumptions are made:
48 * - bbts start at a page boundary, if autolocated on a block boundary
49 * - the space necessary for a bbt in FLASH does not exceed a block boundary
55 #include <linux/mtd/compat.h>
56 #include <linux/mtd/mtd.h>
57 #include <linux/mtd/nand.h>
59 #include <asm/errno.h>
62 * check_pattern - [GENERIC] check if a pattern is in the buffer
63 * @buf: the buffer to search
64 * @len: the length of buffer to search
65 * @paglen: the pagelength
66 * @td: search pattern descriptor
68 * Check for a pattern at the given place. Used to search bad block
69 * tables and good / bad block identifiers.
70 * If the SCAN_EMPTY option is set then check, if all bytes except the
71 * pattern area contain 0xff
74 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
79 end
= paglen
+ td
->offs
;
80 if (td
->options
& NAND_BBT_SCANEMPTY
) {
81 for (i
= 0; i
< end
; i
++) {
88 /* Compare the pattern */
89 for (i
= 0; i
< td
->len
; i
++) {
90 if (p
[i
] != td
->pattern
[i
])
94 if (td
->options
& NAND_BBT_SCANEMPTY
) {
97 for (i
= end
; i
< len
; i
++) {
106 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
107 * @buf: the buffer to search
108 * @td: search pattern descriptor
110 * Check for a pattern at the given place. Used to search bad block
111 * tables and good / bad block identifiers. Same as check_pattern, but
112 * no optional empty check
115 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
120 /* Compare the pattern */
121 for (i
= 0; i
< td
->len
; i
++) {
122 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
129 * read_bbt - [GENERIC] Read the bad block table starting from page
130 * @mtd: MTD device structure
131 * @buf: temporary buffer
132 * @page: the starting page
133 * @num: the number of bbt descriptors to read
134 * @bits: number of bits per block
135 * @offs: offset in the memory table
136 * @reserved_block_code: Pattern to identify reserved blocks
138 * Read the bad block table starting from page.
141 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
142 int bits
, int offs
, int reserved_block_code
)
144 int res
, i
, j
, act
= 0;
145 struct nand_chip
*this = mtd
->priv
;
146 size_t retlen
, len
, totlen
;
148 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
150 totlen
= (num
* bits
) >> 3;
151 from
= ((loff_t
) page
) << this->page_shift
;
154 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
155 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
158 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
161 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
165 for (i
= 0; i
< len
; i
++) {
166 uint8_t dat
= buf
[i
];
167 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
168 uint8_t tmp
= (dat
>> j
) & msk
;
171 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
172 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
173 (loff_t
)((offs
<< 2) +
175 this->bbt_erase_shift
);
176 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
177 mtd
->ecc_stats
.bbtblocks
++;
180 /* Leave it for now, if its matured we can move this
181 * message to MTD_DEBUG_LEVEL0 */
182 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%012llx\n",
183 (loff_t
)((offs
<< 2) + (act
>> 1)) <<
184 this->bbt_erase_shift
);
185 /* Factory marked bad or worn out ? */
187 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
189 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
190 mtd
->ecc_stats
.badblocks
++;
200 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
201 * @mtd: MTD device structure
202 * @buf: temporary buffer
203 * @td: descriptor for the bad block table
204 * @chip: read the table for a specific chip, -1 read all chips.
205 * Applies only if NAND_BBT_PERCHIP option is set
207 * Read the bad block table for all chips starting at a given page
208 * We assume that the bbt bits are in consecutive order.
210 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
212 struct nand_chip
*this = mtd
->priv
;
216 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
217 if (td
->options
& NAND_BBT_PERCHIP
) {
219 for (i
= 0; i
< this->numchips
; i
++) {
220 if (chip
== -1 || chip
== i
)
221 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
224 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
227 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
235 * Scan read raw data from flash
237 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
240 struct mtd_oob_ops ops
;
242 ops
.mode
= MTD_OOB_RAW
;
244 ops
.ooblen
= mtd
->oobsize
;
249 return mtd
->read_oob(mtd
, offs
, &ops
);
253 * Scan write data with oob to flash
255 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
256 uint8_t *buf
, uint8_t *oob
)
258 struct mtd_oob_ops ops
;
260 ops
.mode
= MTD_OOB_PLACE
;
262 ops
.ooblen
= mtd
->oobsize
;
267 return mtd
->write_oob(mtd
, offs
, &ops
);
271 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
272 * @mtd: MTD device structure
273 * @buf: temporary buffer
274 * @td: descriptor for the bad block table
275 * @md: descriptor for the bad block table mirror
277 * Read the bad block table(s) for all chips starting at a given page
278 * We assume that the bbt bits are in consecutive order.
281 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
282 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
284 struct nand_chip
*this = mtd
->priv
;
286 /* Read the primary version, if available */
287 if (td
->options
& NAND_BBT_VERSION
) {
288 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] <<
289 this->page_shift
, mtd
->writesize
);
290 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
291 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
292 td
->pages
[0], td
->version
[0]);
295 /* Read the mirror version, if available */
296 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
297 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] <<
298 this->page_shift
, mtd
->writesize
);
299 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
300 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
301 md
->pages
[0], md
->version
[0]);
307 * Scan a given block full
309 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
310 loff_t offs
, uint8_t *buf
, size_t readlen
,
311 int scanlen
, int len
)
315 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
319 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
320 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
327 * Scan a given block partially
329 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
330 loff_t offs
, uint8_t *buf
, int len
)
332 struct mtd_oob_ops ops
;
335 ops
.ooblen
= mtd
->oobsize
;
339 ops
.mode
= MTD_OOB_PLACE
;
341 for (j
= 0; j
< len
; j
++) {
343 * Read the full oob until read_oob is fixed to
344 * handle single byte reads for 16 bit
347 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
351 if (check_short_pattern(buf
, bd
))
354 offs
+= mtd
->writesize
;
360 * create_bbt - [GENERIC] Create a bad block table by scanning the device
361 * @mtd: MTD device structure
362 * @buf: temporary buffer
363 * @bd: descriptor for the good/bad block search pattern
364 * @chip: create the table for a specific chip, -1 read all chips.
365 * Applies only if NAND_BBT_PERCHIP option is set
367 * Create a bad block table by scanning the device
368 * for the given good/bad block identify pattern
370 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
371 struct nand_bbt_descr
*bd
, int chip
)
373 struct nand_chip
*this = mtd
->priv
;
374 int i
, numblocks
, len
, scanlen
;
379 MTDDEBUG (MTD_DEBUG_LEVEL0
, "Scanning device for bad blocks\n");
381 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
382 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
384 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
390 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
391 /* We need only read few bytes from the OOB area */
395 /* Full page content should be read */
396 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
397 readlen
= len
* mtd
->writesize
;
401 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
402 * below as it makes shifting and masking less painful */
403 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
407 if (chip
>= this->numchips
) {
408 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
409 chip
+ 1, this->numchips
);
412 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
413 startblock
= chip
* numblocks
;
414 numblocks
+= startblock
;
415 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
418 for (i
= startblock
; i
< numblocks
;) {
421 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
422 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
425 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
431 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
432 MTDDEBUG (MTD_DEBUG_LEVEL0
,
433 "Bad eraseblock %d at 0x%012llx\n",
434 i
>> 1, (unsigned long long)from
);
435 mtd
->ecc_stats
.badblocks
++;
439 from
+= (1 << this->bbt_erase_shift
);
445 * search_bbt - [GENERIC] scan the device for a specific bad block table
446 * @mtd: MTD device structure
447 * @buf: temporary buffer
448 * @td: descriptor for the bad block table
450 * Read the bad block table by searching for a given ident pattern.
451 * Search is preformed either from the beginning up or from the end of
452 * the device downwards. The search starts always at the start of a
454 * If the option NAND_BBT_PERCHIP is given, each chip is searched
455 * for a bbt, which contains the bad block information of this chip.
456 * This is necessary to provide support for certain DOC devices.
458 * The bbt ident pattern resides in the oob area of the first page
461 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
463 struct nand_chip
*this = mtd
->priv
;
465 int startblock
, block
, dir
;
466 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
468 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
470 /* Search direction top -> down ? */
471 if (td
->options
& NAND_BBT_LASTBLOCK
) {
472 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
479 /* Do we have a bbt per chip ? */
480 if (td
->options
& NAND_BBT_PERCHIP
) {
481 chips
= this->numchips
;
482 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
483 startblock
&= bbtblocks
- 1;
486 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
489 for (i
= 0; i
< chips
; i
++) {
490 /* Reset version information */
493 /* Scan the maximum number of blocks */
494 for (block
= 0; block
< td
->maxblocks
; block
++) {
496 int actblock
= startblock
+ dir
* block
;
497 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
499 /* Read first page */
500 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
501 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
502 td
->pages
[i
] = actblock
<< blocktopage
;
503 if (td
->options
& NAND_BBT_VERSION
) {
504 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
509 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
511 /* Check, if we found a bbt for each requested chip */
512 for (i
= 0; i
< chips
; i
++) {
513 if (td
->pages
[i
] == -1)
514 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
516 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
523 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
524 * @mtd: MTD device structure
525 * @buf: temporary buffer
526 * @td: descriptor for the bad block table
527 * @md: descriptor for the bad block table mirror
529 * Search and read the bad block table(s)
531 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
533 /* Search the primary table */
534 search_bbt(mtd
, buf
, td
);
536 /* Search the mirror table */
538 search_bbt(mtd
, buf
, md
);
540 /* Force result check */
545 * write_bbt - [GENERIC] (Re)write the bad block table
547 * @mtd: MTD device structure
548 * @buf: temporary buffer
549 * @td: descriptor for the bad block table
550 * @md: descriptor for the bad block table mirror
551 * @chipsel: selector for a specific chip, -1 for all
553 * (Re)write the bad block table
556 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
557 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
560 struct nand_chip
*this = mtd
->priv
;
561 struct erase_info einfo
;
562 int i
, j
, res
, chip
= 0;
563 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
564 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
566 uint8_t rcode
= td
->reserved_block_code
;
567 size_t retlen
, len
= 0;
569 struct mtd_oob_ops ops
;
571 ops
.ooblen
= mtd
->oobsize
;
574 ops
.mode
= MTD_OOB_PLACE
;
578 /* Write bad block table per chip rather than per device ? */
579 if (td
->options
& NAND_BBT_PERCHIP
) {
580 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
581 /* Full device write or specific chip ? */
583 nrchips
= this->numchips
;
585 nrchips
= chipsel
+ 1;
589 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
593 /* Loop through the chips */
594 for (; chip
< nrchips
; chip
++) {
596 /* There was already a version of the table, reuse the page
597 * This applies for absolute placement too, as we have the
598 * page nr. in td->pages.
600 if (td
->pages
[chip
] != -1) {
601 page
= td
->pages
[chip
];
605 /* Automatic placement of the bad block table */
606 /* Search direction top -> down ? */
607 if (td
->options
& NAND_BBT_LASTBLOCK
) {
608 startblock
= numblocks
* (chip
+ 1) - 1;
611 startblock
= chip
* numblocks
;
615 for (i
= 0; i
< td
->maxblocks
; i
++) {
616 int block
= startblock
+ dir
* i
;
617 /* Check, if the block is bad */
618 switch ((this->bbt
[block
>> 2] >>
619 (2 * (block
& 0x03))) & 0x03) {
625 (this->bbt_erase_shift
- this->page_shift
);
626 /* Check, if the block is used by the mirror table */
627 if (!md
|| md
->pages
[chip
] != page
)
630 printk(KERN_ERR
"No space left to write bad block table\n");
634 /* Set up shift count and masks for the flash table */
635 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
638 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
641 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
644 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
647 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
650 default: return -EINVAL
;
653 bbtoffs
= chip
* (numblocks
>> 2);
655 to
= ((loff_t
) page
) << this->page_shift
;
657 /* Must we save the block contents ? */
658 if (td
->options
& NAND_BBT_SAVECONTENT
) {
659 /* Make it block aligned */
660 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
661 len
= 1 << this->bbt_erase_shift
;
662 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
665 printk(KERN_INFO
"nand_bbt: Error "
666 "reading block for writing "
667 "the bad block table\n");
670 printk(KERN_WARNING
"nand_bbt: ECC error "
671 "while reading block for writing "
672 "bad block table\n");
675 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
676 ops
.oobbuf
= &buf
[len
];
677 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
678 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
681 /* Calc the byte offset in the buffer */
682 pageoffs
= page
- (int)(to
>> this->page_shift
);
683 offs
= pageoffs
<< this->page_shift
;
684 /* Preset the bbt area with 0xff */
685 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
686 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
690 len
= (size_t) (numblocks
>> sft
);
691 /* Make it page aligned ! */
692 len
= (len
+ (mtd
->writesize
- 1)) &
693 ~(mtd
->writesize
- 1);
694 /* Preset the buffer with 0xff */
695 memset(buf
, 0xff, len
+
696 (len
>> this->page_shift
)* mtd
->oobsize
);
699 /* Pattern is located in oob area of first page */
700 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
703 if (td
->options
& NAND_BBT_VERSION
)
704 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
706 /* walk through the memory table */
707 for (i
= 0; i
< numblocks
;) {
709 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
710 for (j
= 0; j
< 4; j
++, i
++) {
711 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
712 /* Do not store the reserved bbt blocks ! */
713 buf
[offs
+ (i
>> sft
)] &=
714 ~(msk
[dat
& 0x03] << sftcnt
);
719 memset(&einfo
, 0, sizeof(einfo
));
722 einfo
.len
= 1 << this->bbt_erase_shift
;
723 res
= nand_erase_nand(mtd
, &einfo
, 1);
727 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
731 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, "
732 "version 0x%02X\n", (unsigned long long)to
,
735 /* Mark it as used */
736 td
->pages
[chip
] = page
;
742 "nand_bbt: Error while writing bad block table %d\n", res
);
747 * nand_memory_bbt - [GENERIC] create a memory based bad block table
748 * @mtd: MTD device structure
749 * @bd: descriptor for the good/bad block search pattern
751 * The function creates a memory based bbt by scanning the device
752 * for manufacturer / software marked good / bad blocks
754 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
756 struct nand_chip
*this = mtd
->priv
;
758 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
759 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
763 * check_create - [GENERIC] create and write bbt(s) if necessary
764 * @mtd: MTD device structure
765 * @buf: temporary buffer
766 * @bd: descriptor for the good/bad block search pattern
768 * The function checks the results of the previous call to read_bbt
769 * and creates / updates the bbt(s) if necessary
770 * Creation is necessary if no bbt was found for the chip/device
771 * Update is necessary if one of the tables is missing or the
772 * version nr. of one table is less than the other
774 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
776 int i
, chips
, writeops
, chipsel
, res
;
777 struct nand_chip
*this = mtd
->priv
;
778 struct nand_bbt_descr
*td
= this->bbt_td
;
779 struct nand_bbt_descr
*md
= this->bbt_md
;
780 struct nand_bbt_descr
*rd
, *rd2
;
782 /* Do we have a bbt per chip ? */
783 if (td
->options
& NAND_BBT_PERCHIP
)
784 chips
= this->numchips
;
788 for (i
= 0; i
< chips
; i
++) {
792 /* Per chip or per device ? */
793 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
794 /* Mirrored table avilable ? */
796 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
801 if (td
->pages
[i
] == -1) {
803 td
->version
[i
] = md
->version
[i
];
808 if (md
->pages
[i
] == -1) {
810 md
->version
[i
] = td
->version
[i
];
815 if (td
->version
[i
] == md
->version
[i
]) {
817 if (!(td
->options
& NAND_BBT_VERSION
))
822 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
824 md
->version
[i
] = td
->version
[i
];
828 td
->version
[i
] = md
->version
[i
];
835 if (td
->pages
[i
] == -1) {
843 /* Create the bad block table by scanning the device ? */
844 if (!(td
->options
& NAND_BBT_CREATE
))
847 /* Create the table in memory by scanning the chip(s) */
848 create_bbt(mtd
, buf
, bd
, chipsel
);
854 /* read back first ? */
856 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
857 /* If they weren't versioned, read both. */
859 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
861 /* Write the bad block table to the device ? */
862 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
863 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
868 /* Write the mirror bad block table to the device ? */
869 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
870 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
879 * mark_bbt_regions - [GENERIC] mark the bad block table regions
880 * @mtd: MTD device structure
881 * @td: bad block table descriptor
883 * The bad block table regions are marked as "bad" to prevent
884 * accidental erasures / writes. The regions are identified by
887 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
889 struct nand_chip
*this = mtd
->priv
;
890 int i
, j
, chips
, block
, nrblocks
, update
;
891 uint8_t oldval
, newval
;
893 /* Do we have a bbt per chip ? */
894 if (td
->options
& NAND_BBT_PERCHIP
) {
895 chips
= this->numchips
;
896 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
899 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
902 for (i
= 0; i
< chips
; i
++) {
903 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
904 !(td
->options
& NAND_BBT_WRITE
)) {
905 if (td
->pages
[i
] == -1)
907 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
909 oldval
= this->bbt
[(block
>> 3)];
910 newval
= oldval
| (0x2 << (block
& 0x06));
911 this->bbt
[(block
>> 3)] = newval
;
912 if ((oldval
!= newval
) && td
->reserved_block_code
)
913 nand_update_bbt(mtd
, (loff_t
)block
<<
914 (this->bbt_erase_shift
- 1));
918 if (td
->options
& NAND_BBT_LASTBLOCK
)
919 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
921 block
= i
* nrblocks
;
923 for (j
= 0; j
< td
->maxblocks
; j
++) {
924 oldval
= this->bbt
[(block
>> 3)];
925 newval
= oldval
| (0x2 << (block
& 0x06));
926 this->bbt
[(block
>> 3)] = newval
;
927 if (oldval
!= newval
)
931 /* If we want reserved blocks to be recorded to flash, and some
932 new ones have been marked, then we need to update the stored
933 bbts. This should only happen once. */
934 if (update
&& td
->reserved_block_code
)
935 nand_update_bbt(mtd
, (loff_t
)(block
- 2) <<
936 (this->bbt_erase_shift
- 1));
941 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
942 * @mtd: MTD device structure
943 * @bd: descriptor for the good/bad block search pattern
945 * The function checks, if a bad block table(s) is/are already
946 * available. If not it scans the device for manufacturer
947 * marked good / bad blocks and writes the bad block table(s) to
948 * the selected place.
950 * The bad block table memory is allocated here. It must be freed
951 * by calling the nand_free_bbt function.
954 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
956 struct nand_chip
*this = mtd
->priv
;
959 struct nand_bbt_descr
*td
= this->bbt_td
;
960 struct nand_bbt_descr
*md
= this->bbt_md
;
962 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
963 /* Allocate memory (2bit per block) and clear the memory bad block table */
964 this->bbt
= kzalloc(len
, GFP_KERNEL
);
966 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
970 /* If no primary table decriptor is given, scan the device
971 * to build a memory based bad block table
974 if ((res
= nand_memory_bbt(mtd
, bd
))) {
975 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
982 /* Allocate a temporary buffer for one eraseblock incl. oob */
983 len
= (1 << this->bbt_erase_shift
);
984 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
987 printk(KERN_ERR
"nand_bbt: Out of memory\n");
993 /* Is the bbt at a given page ? */
994 if (td
->options
& NAND_BBT_ABSPAGE
) {
995 res
= read_abs_bbts(mtd
, buf
, td
, md
);
997 /* Search the bad block table using a pattern in oob */
998 res
= search_read_bbts(mtd
, buf
, td
, md
);
1002 res
= check_create(mtd
, buf
, bd
);
1004 /* Prevent the bbt regions from erasing / writing */
1005 mark_bbt_region(mtd
, td
);
1007 mark_bbt_region(mtd
, md
);
1014 * nand_update_bbt - [NAND Interface] update bad block table(s)
1015 * @mtd: MTD device structure
1016 * @offs: the offset of the newly marked block
1018 * The function updates the bad block table(s)
1020 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1022 struct nand_chip
*this = mtd
->priv
;
1023 int len
, res
= 0, writeops
= 0;
1026 struct nand_bbt_descr
*td
= this->bbt_td
;
1027 struct nand_bbt_descr
*md
= this->bbt_md
;
1029 if (!this->bbt
|| !td
)
1032 /* Allocate a temporary buffer for one eraseblock incl. oob */
1033 len
= (1 << this->bbt_erase_shift
);
1034 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1035 buf
= kmalloc(len
, GFP_KERNEL
);
1037 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1041 writeops
= md
!= NULL
? 0x03 : 0x01;
1043 /* Do we have a bbt per chip ? */
1044 if (td
->options
& NAND_BBT_PERCHIP
) {
1045 chip
= (int)(offs
>> this->chip_shift
);
1052 td
->version
[chip
]++;
1054 md
->version
[chip
]++;
1056 /* Write the bad block table to the device ? */
1057 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1058 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1062 /* Write the mirror bad block table to the device ? */
1063 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1064 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1072 /* Define some generic bad / good block scan pattern which are used
1073 * while scanning a device for factory marked good / bad blocks. */
1074 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1076 static struct nand_bbt_descr smallpage_memorybased
= {
1077 .options
= NAND_BBT_SCAN2NDPAGE
,
1080 .pattern
= scan_ff_pattern
1083 static struct nand_bbt_descr largepage_memorybased
= {
1087 .pattern
= scan_ff_pattern
1090 static struct nand_bbt_descr smallpage_flashbased
= {
1091 .options
= NAND_BBT_SCAN2NDPAGE
,
1094 .pattern
= scan_ff_pattern
1097 static struct nand_bbt_descr largepage_flashbased
= {
1098 .options
= NAND_BBT_SCAN2NDPAGE
,
1101 .pattern
= scan_ff_pattern
1104 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1106 static struct nand_bbt_descr agand_flashbased
= {
1107 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1110 .pattern
= scan_agand_pattern
1113 /* Generic flash bbt decriptors
1115 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1116 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1118 static struct nand_bbt_descr bbt_main_descr
= {
1119 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1120 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1125 .pattern
= bbt_pattern
1128 static struct nand_bbt_descr bbt_mirror_descr
= {
1129 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1130 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1135 .pattern
= mirror_pattern
1139 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1140 * @mtd: MTD device structure
1142 * This function selects the default bad block table
1143 * support for the device and calls the nand_scan_bbt function
1146 int nand_default_bbt(struct mtd_info
*mtd
)
1148 struct nand_chip
*this = mtd
->priv
;
1150 /* Default for AG-AND. We must use a flash based
1151 * bad block table as the devices have factory marked
1152 * _good_ blocks. Erasing those blocks leads to loss
1153 * of the good / bad information, so we _must_ store
1154 * this information in a good / bad table during
1157 if (this->options
& NAND_IS_AND
) {
1158 /* Use the default pattern descriptors */
1159 if (!this->bbt_td
) {
1160 this->bbt_td
= &bbt_main_descr
;
1161 this->bbt_md
= &bbt_mirror_descr
;
1163 this->options
|= NAND_USE_FLASH_BBT
;
1164 return nand_scan_bbt(mtd
, &agand_flashbased
);
1167 /* Is a flash based bad block table requested ? */
1168 if (this->options
& NAND_USE_FLASH_BBT
) {
1169 /* Use the default pattern descriptors */
1170 if (!this->bbt_td
) {
1171 this->bbt_td
= &bbt_main_descr
;
1172 this->bbt_md
= &bbt_mirror_descr
;
1174 if (!this->badblock_pattern
) {
1175 this->badblock_pattern
= (mtd
->writesize
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1178 this->bbt_td
= NULL
;
1179 this->bbt_md
= NULL
;
1180 if (!this->badblock_pattern
) {
1181 this->badblock_pattern
= (mtd
->writesize
> 512) ?
1182 &largepage_memorybased
: &smallpage_memorybased
;
1185 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1189 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1190 * @mtd: MTD device structure
1191 * @offs: offset in the device
1192 * @allowbbt: allow access to bad block table region
1195 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1197 struct nand_chip
*this = mtd
->priv
;
1201 /* Get block number * 2 */
1202 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1203 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1205 MTDDEBUG (MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1206 "(block %d) 0x%02x\n", (unsigned int)offs
, res
, block
>> 1);
1214 return allowbbt
? 0 : 1;