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22 * If one of the bbt's is out of date or does not exist it is (re)created.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
53 #include <linux/slab.h>
54 #include <linux/types.h>
55 #include <linux/mtd/mtd.h>
56 #include <linux/mtd/nand.h>
57 #include <linux/mtd/nand_ecc.h>
58 #include <linux/bitops.h>
59 #include <linux/delay.h>
60 #include <linux/vmalloc.h>
63 * check_pattern - [GENERIC] check if a pattern is in the buffer
64 * @buf: the buffer to search
65 * @len: the length of buffer to search
66 * @paglen: the pagelength
67 * @td: search pattern descriptor
69 * Check for a pattern at the given place. Used to search bad block
70 * tables and good / bad block identifiers.
71 * If the SCAN_EMPTY option is set then check, if all bytes except the
72 * pattern area contain 0xff
75 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
80 end
= paglen
+ td
->offs
;
81 if (td
->options
& NAND_BBT_SCANEMPTY
) {
82 for (i
= 0; i
< end
; i
++) {
89 /* Compare the pattern */
90 for (i
= 0; i
< td
->len
; i
++) {
91 if (p
[i
] != td
->pattern
[i
])
95 /* Check both positions 1 and 6 for pattern? */
96 if (td
->options
& NAND_BBT_SCANBYTE1AND6
) {
97 if (td
->options
& NAND_BBT_SCANEMPTY
) {
99 end
+= NAND_SMALL_BADBLOCK_POS
- td
->offs
;
100 /* Check region between positions 1 and 6 */
101 for (i
= 0; i
< NAND_SMALL_BADBLOCK_POS
- td
->offs
- td
->len
;
108 p
+= NAND_SMALL_BADBLOCK_POS
- td
->offs
;
110 /* Compare the pattern */
111 for (i
= 0; i
< td
->len
; i
++) {
112 if (p
[i
] != td
->pattern
[i
])
117 if (td
->options
& NAND_BBT_SCANEMPTY
) {
120 for (i
= end
; i
< len
; i
++) {
129 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
130 * @buf: the buffer to search
131 * @td: search pattern descriptor
133 * Check for a pattern at the given place. Used to search bad block
134 * tables and good / bad block identifiers. Same as check_pattern, but
135 * no optional empty check
138 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
143 /* Compare the pattern */
144 for (i
= 0; i
< td
->len
; i
++) {
145 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
148 /* Need to check location 1 AND 6? */
149 if (td
->options
& NAND_BBT_SCANBYTE1AND6
) {
150 for (i
= 0; i
< td
->len
; i
++) {
151 if (p
[NAND_SMALL_BADBLOCK_POS
+ i
] != td
->pattern
[i
])
159 * read_bbt - [GENERIC] Read the bad block table starting from page
160 * @mtd: MTD device structure
161 * @buf: temporary buffer
162 * @page: the starting page
163 * @num: the number of bbt descriptors to read
164 * @bits: number of bits per block
165 * @offs: offset in the memory table
166 * @reserved_block_code: Pattern to identify reserved blocks
168 * Read the bad block table starting from page.
171 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
172 int bits
, int offs
, int reserved_block_code
)
174 int res
, i
, j
, act
= 0;
175 struct nand_chip
*this = mtd
->priv
;
176 size_t retlen
, len
, totlen
;
178 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
180 totlen
= (num
* bits
) >> 3;
181 from
= ((loff_t
) page
) << this->page_shift
;
184 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
185 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
188 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
191 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
195 for (i
= 0; i
< len
; i
++) {
196 uint8_t dat
= buf
[i
];
197 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
198 uint8_t tmp
= (dat
>> j
) & msk
;
201 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
202 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
203 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
204 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
205 mtd
->ecc_stats
.bbtblocks
++;
208 /* Leave it for now, if its matured we can move this
209 * message to MTD_DEBUG_LEVEL0 */
210 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%012llx\n",
211 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
212 /* Factory marked bad or worn out ? */
214 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
216 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
217 mtd
->ecc_stats
.badblocks
++;
227 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
228 * @mtd: MTD device structure
229 * @buf: temporary buffer
230 * @td: descriptor for the bad block table
231 * @chip: read the table for a specific chip, -1 read all chips.
232 * Applies only if NAND_BBT_PERCHIP option is set
234 * Read the bad block table for all chips starting at a given page
235 * We assume that the bbt bits are in consecutive order.
237 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
239 struct nand_chip
*this = mtd
->priv
;
243 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
244 if (td
->options
& NAND_BBT_PERCHIP
) {
246 for (i
= 0; i
< this->numchips
; i
++) {
247 if (chip
== -1 || chip
== i
)
248 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
251 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
254 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
262 * Scan read raw data from flash
264 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
267 struct mtd_oob_ops ops
;
270 ops
.mode
= MTD_OOB_RAW
;
272 ops
.ooblen
= mtd
->oobsize
;
276 if (len
<= mtd
->writesize
) {
277 ops
.oobbuf
= buf
+ len
;
280 return mtd
->read_oob(mtd
, offs
, &ops
);
282 ops
.oobbuf
= buf
+ mtd
->writesize
;
284 ops
.len
= mtd
->writesize
;
285 res
= mtd
->read_oob(mtd
, offs
, &ops
);
291 buf
+= mtd
->oobsize
+ mtd
->writesize
;
292 len
-= mtd
->writesize
;
298 * Scan write data with oob to flash
300 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
301 uint8_t *buf
, uint8_t *oob
)
303 struct mtd_oob_ops ops
;
305 ops
.mode
= MTD_OOB_PLACE
;
307 ops
.ooblen
= mtd
->oobsize
;
312 return mtd
->write_oob(mtd
, offs
, &ops
);
316 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
317 * @mtd: MTD device structure
318 * @buf: temporary buffer
319 * @td: descriptor for the bad block table
320 * @md: descriptor for the bad block table mirror
322 * Read the bad block table(s) for all chips starting at a given page
323 * We assume that the bbt bits are in consecutive order.
326 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
327 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
329 struct nand_chip
*this = mtd
->priv
;
331 /* Read the primary version, if available */
332 if (td
->options
& NAND_BBT_VERSION
) {
333 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
335 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
336 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
337 td
->pages
[0], td
->version
[0]);
340 /* Read the mirror version, if available */
341 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
342 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
344 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
345 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
346 md
->pages
[0], md
->version
[0]);
352 * Scan a given block full
354 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
355 loff_t offs
, uint8_t *buf
, size_t readlen
,
356 int scanlen
, int len
)
360 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
364 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
365 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
372 * Scan a given block partially
374 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
375 loff_t offs
, uint8_t *buf
, int len
)
377 struct mtd_oob_ops ops
;
380 ops
.ooblen
= mtd
->oobsize
;
384 ops
.mode
= MTD_OOB_PLACE
;
386 for (j
= 0; j
< len
; j
++) {
388 * Read the full oob until read_oob is fixed to
389 * handle single byte reads for 16 bit
392 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
396 if (check_short_pattern(buf
, bd
))
399 offs
+= mtd
->writesize
;
405 * create_bbt - [GENERIC] Create a bad block table by scanning the device
406 * @mtd: MTD device structure
407 * @buf: temporary buffer
408 * @bd: descriptor for the good/bad block search pattern
409 * @chip: create the table for a specific chip, -1 read all chips.
410 * Applies only if NAND_BBT_PERCHIP option is set
412 * Create a bad block table by scanning the device
413 * for the given good/bad block identify pattern
415 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
416 struct nand_bbt_descr
*bd
, int chip
)
418 struct nand_chip
*this = mtd
->priv
;
419 int i
, numblocks
, len
, scanlen
;
424 printk(KERN_INFO
"Scanning device for bad blocks\n");
426 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
427 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
428 else if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
433 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
434 /* We need only read few bytes from the OOB area */
438 /* Full page content should be read */
439 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
440 readlen
= len
* mtd
->writesize
;
444 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
445 * below as it makes shifting and masking less painful */
446 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
450 if (chip
>= this->numchips
) {
451 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
452 chip
+ 1, this->numchips
);
455 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
456 startblock
= chip
* numblocks
;
457 numblocks
+= startblock
;
458 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
461 if (this->options
& NAND_BBT_SCANLASTPAGE
)
462 from
+= mtd
->erasesize
- (mtd
->writesize
* len
);
464 for (i
= startblock
; i
< numblocks
;) {
467 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
468 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
471 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
477 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
478 printk(KERN_WARNING
"Bad eraseblock %d at 0x%012llx\n",
479 i
>> 1, (unsigned long long)from
);
480 mtd
->ecc_stats
.badblocks
++;
484 from
+= (1 << this->bbt_erase_shift
);
490 * search_bbt - [GENERIC] scan the device for a specific bad block table
491 * @mtd: MTD device structure
492 * @buf: temporary buffer
493 * @td: descriptor for the bad block table
495 * Read the bad block table by searching for a given ident pattern.
496 * Search is preformed either from the beginning up or from the end of
497 * the device downwards. The search starts always at the start of a
499 * If the option NAND_BBT_PERCHIP is given, each chip is searched
500 * for a bbt, which contains the bad block information of this chip.
501 * This is necessary to provide support for certain DOC devices.
503 * The bbt ident pattern resides in the oob area of the first page
506 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
508 struct nand_chip
*this = mtd
->priv
;
510 int bits
, startblock
, block
, dir
;
511 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
513 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
515 /* Search direction top -> down ? */
516 if (td
->options
& NAND_BBT_LASTBLOCK
) {
517 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
524 /* Do we have a bbt per chip ? */
525 if (td
->options
& NAND_BBT_PERCHIP
) {
526 chips
= this->numchips
;
527 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
528 startblock
&= bbtblocks
- 1;
531 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
534 /* Number of bits for each erase block in the bbt */
535 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
537 for (i
= 0; i
< chips
; i
++) {
538 /* Reset version information */
541 /* Scan the maximum number of blocks */
542 for (block
= 0; block
< td
->maxblocks
; block
++) {
544 int actblock
= startblock
+ dir
* block
;
545 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
547 /* Read first page */
548 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
549 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
550 td
->pages
[i
] = actblock
<< blocktopage
;
551 if (td
->options
& NAND_BBT_VERSION
) {
552 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
557 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
559 /* Check, if we found a bbt for each requested chip */
560 for (i
= 0; i
< chips
; i
++) {
561 if (td
->pages
[i
] == -1)
562 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
564 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
571 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
572 * @mtd: MTD device structure
573 * @buf: temporary buffer
574 * @td: descriptor for the bad block table
575 * @md: descriptor for the bad block table mirror
577 * Search and read the bad block table(s)
579 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
581 /* Search the primary table */
582 search_bbt(mtd
, buf
, td
);
584 /* Search the mirror table */
586 search_bbt(mtd
, buf
, md
);
588 /* Force result check */
593 * write_bbt - [GENERIC] (Re)write the bad block table
595 * @mtd: MTD device structure
596 * @buf: temporary buffer
597 * @td: descriptor for the bad block table
598 * @md: descriptor for the bad block table mirror
599 * @chipsel: selector for a specific chip, -1 for all
601 * (Re)write the bad block table
604 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
605 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
608 struct nand_chip
*this = mtd
->priv
;
609 struct erase_info einfo
;
610 int i
, j
, res
, chip
= 0;
611 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
612 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
614 uint8_t rcode
= td
->reserved_block_code
;
615 size_t retlen
, len
= 0;
617 struct mtd_oob_ops ops
;
619 ops
.ooblen
= mtd
->oobsize
;
622 ops
.mode
= MTD_OOB_PLACE
;
626 /* Write bad block table per chip rather than per device ? */
627 if (td
->options
& NAND_BBT_PERCHIP
) {
628 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
629 /* Full device write or specific chip ? */
631 nrchips
= this->numchips
;
633 nrchips
= chipsel
+ 1;
637 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
641 /* Loop through the chips */
642 for (; chip
< nrchips
; chip
++) {
644 /* There was already a version of the table, reuse the page
645 * This applies for absolute placement too, as we have the
646 * page nr. in td->pages.
648 if (td
->pages
[chip
] != -1) {
649 page
= td
->pages
[chip
];
653 /* Automatic placement of the bad block table */
654 /* Search direction top -> down ? */
655 if (td
->options
& NAND_BBT_LASTBLOCK
) {
656 startblock
= numblocks
* (chip
+ 1) - 1;
659 startblock
= chip
* numblocks
;
663 for (i
= 0; i
< td
->maxblocks
; i
++) {
664 int block
= startblock
+ dir
* i
;
665 /* Check, if the block is bad */
666 switch ((this->bbt
[block
>> 2] >>
667 (2 * (block
& 0x03))) & 0x03) {
673 (this->bbt_erase_shift
- this->page_shift
);
674 /* Check, if the block is used by the mirror table */
675 if (!md
|| md
->pages
[chip
] != page
)
678 printk(KERN_ERR
"No space left to write bad block table\n");
682 /* Set up shift count and masks for the flash table */
683 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
686 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
689 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
692 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
695 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
698 default: return -EINVAL
;
701 bbtoffs
= chip
* (numblocks
>> 2);
703 to
= ((loff_t
) page
) << this->page_shift
;
705 /* Must we save the block contents ? */
706 if (td
->options
& NAND_BBT_SAVECONTENT
) {
707 /* Make it block aligned */
708 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
709 len
= 1 << this->bbt_erase_shift
;
710 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
713 printk(KERN_INFO
"nand_bbt: Error "
714 "reading block for writing "
715 "the bad block table\n");
718 printk(KERN_WARNING
"nand_bbt: ECC error "
719 "while reading block for writing "
720 "bad block table\n");
723 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
724 ops
.oobbuf
= &buf
[len
];
725 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
726 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
729 /* Calc the byte offset in the buffer */
730 pageoffs
= page
- (int)(to
>> this->page_shift
);
731 offs
= pageoffs
<< this->page_shift
;
732 /* Preset the bbt area with 0xff */
733 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
734 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
738 len
= (size_t) (numblocks
>> sft
);
739 /* Make it page aligned ! */
740 len
= (len
+ (mtd
->writesize
- 1)) &
741 ~(mtd
->writesize
- 1);
742 /* Preset the buffer with 0xff */
743 memset(buf
, 0xff, len
+
744 (len
>> this->page_shift
)* mtd
->oobsize
);
747 /* Pattern is located in oob area of first page */
748 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
751 if (td
->options
& NAND_BBT_VERSION
)
752 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
754 /* walk through the memory table */
755 for (i
= 0; i
< numblocks
;) {
757 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
758 for (j
= 0; j
< 4; j
++, i
++) {
759 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
760 /* Do not store the reserved bbt blocks ! */
761 buf
[offs
+ (i
>> sft
)] &=
762 ~(msk
[dat
& 0x03] << sftcnt
);
767 memset(&einfo
, 0, sizeof(einfo
));
770 einfo
.len
= 1 << this->bbt_erase_shift
;
771 res
= nand_erase_nand(mtd
, &einfo
, 1);
775 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
779 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, version "
780 "0x%02X\n", (unsigned long long)to
, td
->version
[chip
]);
782 /* Mark it as used */
783 td
->pages
[chip
] = page
;
789 "nand_bbt: Error while writing bad block table %d\n", res
);
794 * nand_memory_bbt - [GENERIC] create a memory based bad block table
795 * @mtd: MTD device structure
796 * @bd: descriptor for the good/bad block search pattern
798 * The function creates a memory based bbt by scanning the device
799 * for manufacturer / software marked good / bad blocks
801 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
803 struct nand_chip
*this = mtd
->priv
;
805 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
806 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
810 * check_create - [GENERIC] create and write bbt(s) if necessary
811 * @mtd: MTD device structure
812 * @buf: temporary buffer
813 * @bd: descriptor for the good/bad block search pattern
815 * The function checks the results of the previous call to read_bbt
816 * and creates / updates the bbt(s) if necessary
817 * Creation is necessary if no bbt was found for the chip/device
818 * Update is necessary if one of the tables is missing or the
819 * version nr. of one table is less than the other
821 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
823 int i
, chips
, writeops
, chipsel
, res
;
824 struct nand_chip
*this = mtd
->priv
;
825 struct nand_bbt_descr
*td
= this->bbt_td
;
826 struct nand_bbt_descr
*md
= this->bbt_md
;
827 struct nand_bbt_descr
*rd
, *rd2
;
829 /* Do we have a bbt per chip ? */
830 if (td
->options
& NAND_BBT_PERCHIP
)
831 chips
= this->numchips
;
835 for (i
= 0; i
< chips
; i
++) {
839 /* Per chip or per device ? */
840 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
841 /* Mirrored table avilable ? */
843 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
848 if (td
->pages
[i
] == -1) {
850 td
->version
[i
] = md
->version
[i
];
855 if (md
->pages
[i
] == -1) {
857 md
->version
[i
] = td
->version
[i
];
862 if (td
->version
[i
] == md
->version
[i
]) {
864 if (!(td
->options
& NAND_BBT_VERSION
))
869 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
871 md
->version
[i
] = td
->version
[i
];
875 td
->version
[i
] = md
->version
[i
];
882 if (td
->pages
[i
] == -1) {
890 /* Create the bad block table by scanning the device ? */
891 if (!(td
->options
& NAND_BBT_CREATE
))
894 /* Create the table in memory by scanning the chip(s) */
895 create_bbt(mtd
, buf
, bd
, chipsel
);
901 /* read back first ? */
903 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
904 /* If they weren't versioned, read both. */
906 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
908 /* Write the bad block table to the device ? */
909 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
910 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
915 /* Write the mirror bad block table to the device ? */
916 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
917 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
926 * mark_bbt_regions - [GENERIC] mark the bad block table regions
927 * @mtd: MTD device structure
928 * @td: bad block table descriptor
930 * The bad block table regions are marked as "bad" to prevent
931 * accidental erasures / writes. The regions are identified by
934 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
936 struct nand_chip
*this = mtd
->priv
;
937 int i
, j
, chips
, block
, nrblocks
, update
;
938 uint8_t oldval
, newval
;
940 /* Do we have a bbt per chip ? */
941 if (td
->options
& NAND_BBT_PERCHIP
) {
942 chips
= this->numchips
;
943 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
946 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
949 for (i
= 0; i
< chips
; i
++) {
950 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
951 !(td
->options
& NAND_BBT_WRITE
)) {
952 if (td
->pages
[i
] == -1)
954 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
956 oldval
= this->bbt
[(block
>> 3)];
957 newval
= oldval
| (0x2 << (block
& 0x06));
958 this->bbt
[(block
>> 3)] = newval
;
959 if ((oldval
!= newval
) && td
->reserved_block_code
)
960 nand_update_bbt(mtd
, (loff_t
)block
<< (this->bbt_erase_shift
- 1));
964 if (td
->options
& NAND_BBT_LASTBLOCK
)
965 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
967 block
= i
* nrblocks
;
969 for (j
= 0; j
< td
->maxblocks
; j
++) {
970 oldval
= this->bbt
[(block
>> 3)];
971 newval
= oldval
| (0x2 << (block
& 0x06));
972 this->bbt
[(block
>> 3)] = newval
;
973 if (oldval
!= newval
)
977 /* If we want reserved blocks to be recorded to flash, and some
978 new ones have been marked, then we need to update the stored
979 bbts. This should only happen once. */
980 if (update
&& td
->reserved_block_code
)
981 nand_update_bbt(mtd
, (loff_t
)(block
- 2) << (this->bbt_erase_shift
- 1));
986 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
987 * @mtd: MTD device structure
988 * @bd: descriptor for the good/bad block search pattern
990 * The function checks, if a bad block table(s) is/are already
991 * available. If not it scans the device for manufacturer
992 * marked good / bad blocks and writes the bad block table(s) to
993 * the selected place.
995 * The bad block table memory is allocated here. It must be freed
996 * by calling the nand_free_bbt function.
999 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1001 struct nand_chip
*this = mtd
->priv
;
1004 struct nand_bbt_descr
*td
= this->bbt_td
;
1005 struct nand_bbt_descr
*md
= this->bbt_md
;
1007 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1008 /* Allocate memory (2bit per block) and clear the memory bad block table */
1009 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1011 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
1015 /* If no primary table decriptor is given, scan the device
1016 * to build a memory based bad block table
1019 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1020 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1027 /* Allocate a temporary buffer for one eraseblock incl. oob */
1028 len
= (1 << this->bbt_erase_shift
);
1029 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1032 printk(KERN_ERR
"nand_bbt: Out of memory\n");
1038 /* Is the bbt at a given page ? */
1039 if (td
->options
& NAND_BBT_ABSPAGE
) {
1040 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1042 /* Search the bad block table using a pattern in oob */
1043 res
= search_read_bbts(mtd
, buf
, td
, md
);
1047 res
= check_create(mtd
, buf
, bd
);
1049 /* Prevent the bbt regions from erasing / writing */
1050 mark_bbt_region(mtd
, td
);
1052 mark_bbt_region(mtd
, md
);
1059 * nand_update_bbt - [NAND Interface] update bad block table(s)
1060 * @mtd: MTD device structure
1061 * @offs: the offset of the newly marked block
1063 * The function updates the bad block table(s)
1065 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1067 struct nand_chip
*this = mtd
->priv
;
1068 int len
, res
= 0, writeops
= 0;
1071 struct nand_bbt_descr
*td
= this->bbt_td
;
1072 struct nand_bbt_descr
*md
= this->bbt_md
;
1074 if (!this->bbt
|| !td
)
1077 /* Allocate a temporary buffer for one eraseblock incl. oob */
1078 len
= (1 << this->bbt_erase_shift
);
1079 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1080 buf
= kmalloc(len
, GFP_KERNEL
);
1082 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1086 writeops
= md
!= NULL
? 0x03 : 0x01;
1088 /* Do we have a bbt per chip ? */
1089 if (td
->options
& NAND_BBT_PERCHIP
) {
1090 chip
= (int)(offs
>> this->chip_shift
);
1097 td
->version
[chip
]++;
1099 md
->version
[chip
]++;
1101 /* Write the bad block table to the device ? */
1102 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1103 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1107 /* Write the mirror bad block table to the device ? */
1108 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1109 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1117 /* Define some generic bad / good block scan pattern which are used
1118 * while scanning a device for factory marked good / bad blocks. */
1119 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1121 static struct nand_bbt_descr smallpage_flashbased
= {
1122 .options
= NAND_BBT_SCAN2NDPAGE
,
1123 .offs
= NAND_SMALL_BADBLOCK_POS
,
1125 .pattern
= scan_ff_pattern
1128 static struct nand_bbt_descr largepage_flashbased
= {
1129 .options
= NAND_BBT_SCAN2NDPAGE
,
1130 .offs
= NAND_LARGE_BADBLOCK_POS
,
1132 .pattern
= scan_ff_pattern
1135 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1137 static struct nand_bbt_descr agand_flashbased
= {
1138 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1141 .pattern
= scan_agand_pattern
1144 /* Generic flash bbt decriptors
1146 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1147 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1149 static struct nand_bbt_descr bbt_main_descr
= {
1150 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1151 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1156 .pattern
= bbt_pattern
1159 static struct nand_bbt_descr bbt_mirror_descr
= {
1160 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1161 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1166 .pattern
= mirror_pattern
1169 #define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
1170 NAND_BBT_SCANBYTE1AND6)
1172 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1173 * @this: NAND chip to create descriptor for
1175 * This function allocates and initializes a nand_bbt_descr for BBM detection
1176 * based on the properties of "this". The new descriptor is stored in
1177 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1178 * passed to this function.
1180 * TODO: Handle other flags, replace other static structs
1181 * (e.g. handle NAND_BBT_FLASH for flash-based BBT,
1182 * replace smallpage_flashbased)
1185 static int nand_create_default_bbt_descr(struct nand_chip
*this)
1187 struct nand_bbt_descr
*bd
;
1188 if (this->badblock_pattern
) {
1189 printk(KERN_WARNING
"BBT descr already allocated; not replacing.\n");
1192 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1194 printk(KERN_ERR
"nand_create_default_bbt_descr: Out of memory\n");
1197 bd
->options
= this->options
& BBT_SCAN_OPTIONS
;
1198 bd
->offs
= this->badblockpos
;
1199 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1200 bd
->pattern
= scan_ff_pattern
;
1201 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1202 this->badblock_pattern
= bd
;
1207 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1208 * @mtd: MTD device structure
1210 * This function selects the default bad block table
1211 * support for the device and calls the nand_scan_bbt function
1214 int nand_default_bbt(struct mtd_info
*mtd
)
1216 struct nand_chip
*this = mtd
->priv
;
1218 /* Default for AG-AND. We must use a flash based
1219 * bad block table as the devices have factory marked
1220 * _good_ blocks. Erasing those blocks leads to loss
1221 * of the good / bad information, so we _must_ store
1222 * this information in a good / bad table during
1225 if (this->options
& NAND_IS_AND
) {
1226 /* Use the default pattern descriptors */
1227 if (!this->bbt_td
) {
1228 this->bbt_td
= &bbt_main_descr
;
1229 this->bbt_md
= &bbt_mirror_descr
;
1231 this->options
|= NAND_USE_FLASH_BBT
;
1232 return nand_scan_bbt(mtd
, &agand_flashbased
);
1235 /* Is a flash based bad block table requested ? */
1236 if (this->options
& NAND_USE_FLASH_BBT
) {
1237 /* Use the default pattern descriptors */
1238 if (!this->bbt_td
) {
1239 this->bbt_td
= &bbt_main_descr
;
1240 this->bbt_md
= &bbt_mirror_descr
;
1242 if (!this->badblock_pattern
) {
1243 this->badblock_pattern
= (mtd
->writesize
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1246 this->bbt_td
= NULL
;
1247 this->bbt_md
= NULL
;
1248 if (!this->badblock_pattern
)
1249 nand_create_default_bbt_descr(this);
1251 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1255 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1256 * @mtd: MTD device structure
1257 * @offs: offset in the device
1258 * @allowbbt: allow access to bad block table region
1261 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1263 struct nand_chip
*this = mtd
->priv
;
1267 /* Get block number * 2 */
1268 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1269 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1271 DEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1272 (unsigned int)offs
, block
>> 1, res
);
1280 return allowbbt
? 0 : 1;
1285 EXPORT_SYMBOL(nand_scan_bbt
);
1286 EXPORT_SYMBOL(nand_default_bbt
);