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22 * If one of the bbt's is out of date or does not exist it is (re)created.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/mtd/compatmac.h>
59 #include <linux/bitops.h>
60 #include <linux/delay.h>
61 #include <linux/vmalloc.h>
64 * check_pattern - [GENERIC] check if a pattern is in the buffer
65 * @buf: the buffer to search
66 * @len: the length of buffer to search
67 * @paglen: the pagelength
68 * @td: search pattern descriptor
70 * Check for a pattern at the given place. Used to search bad block
71 * tables and good / bad block identifiers.
72 * If the SCAN_EMPTY option is set then check, if all bytes except the
73 * pattern area contain 0xff
76 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
81 end
= paglen
+ td
->offs
;
82 if (td
->options
& NAND_BBT_SCANEMPTY
) {
83 for (i
= 0; i
< end
; i
++) {
90 /* Compare the pattern */
91 for (i
= 0; i
< td
->len
; i
++) {
92 if (p
[i
] != td
->pattern
[i
])
96 if (td
->options
& NAND_BBT_SCANEMPTY
) {
99 for (i
= end
; i
< len
; i
++) {
108 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
109 * @buf: the buffer to search
110 * @td: search pattern descriptor
112 * Check for a pattern at the given place. Used to search bad block
113 * tables and good / bad block identifiers. Same as check_pattern, but
114 * no optional empty check
117 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
122 /* Compare the pattern */
123 for (i
= 0; i
< td
->len
; i
++) {
124 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
131 * read_bbt - [GENERIC] Read the bad block table starting from page
132 * @mtd: MTD device structure
133 * @buf: temporary buffer
134 * @page: the starting page
135 * @num: the number of bbt descriptors to read
136 * @bits: number of bits per block
137 * @offs: offset in the memory table
138 * @reserved_block_code: Pattern to identify reserved blocks
140 * Read the bad block table starting from page.
143 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
144 int bits
, int offs
, int reserved_block_code
)
146 int res
, i
, j
, act
= 0;
147 struct nand_chip
*this = mtd
->priv
;
148 size_t retlen
, len
, totlen
;
150 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
152 totlen
= (num
* bits
) >> 3;
153 from
= ((loff_t
) page
) << this->page_shift
;
156 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
157 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
160 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
163 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
167 for (i
= 0; i
< len
; i
++) {
168 uint8_t dat
= buf
[i
];
169 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
170 uint8_t tmp
= (dat
>> j
) & msk
;
173 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
174 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
175 (loff_t
)((offs
<< 2) + (act
>> 1)) << 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)) << this->bbt_erase_shift
);
184 /* Factory marked bad or worn out ? */
186 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
188 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
189 mtd
->ecc_stats
.badblocks
++;
199 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
200 * @mtd: MTD device structure
201 * @buf: temporary buffer
202 * @td: descriptor for the bad block table
203 * @chip: read the table for a specific chip, -1 read all chips.
204 * Applies only if NAND_BBT_PERCHIP option is set
206 * Read the bad block table for all chips starting at a given page
207 * We assume that the bbt bits are in consecutive order.
209 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
211 struct nand_chip
*this = mtd
->priv
;
215 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
216 if (td
->options
& NAND_BBT_PERCHIP
) {
218 for (i
= 0; i
< this->numchips
; i
++) {
219 if (chip
== -1 || chip
== i
)
220 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
223 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
226 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
234 * Scan read raw data from flash
236 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
239 struct mtd_oob_ops ops
;
242 ops
.mode
= MTD_OOB_RAW
;
244 ops
.ooblen
= mtd
->oobsize
;
248 if (len
<= mtd
->writesize
) {
249 ops
.oobbuf
= buf
+ len
;
252 return mtd
->read_oob(mtd
, offs
, &ops
);
254 ops
.oobbuf
= buf
+ mtd
->writesize
;
256 ops
.len
= mtd
->writesize
;
257 res
= mtd
->read_oob(mtd
, offs
, &ops
);
263 buf
+= mtd
->oobsize
+ mtd
->writesize
;
264 len
-= mtd
->writesize
;
270 * Scan write data with oob to flash
272 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
273 uint8_t *buf
, uint8_t *oob
)
275 struct mtd_oob_ops ops
;
277 ops
.mode
= MTD_OOB_PLACE
;
279 ops
.ooblen
= mtd
->oobsize
;
284 return mtd
->write_oob(mtd
, offs
, &ops
);
288 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
289 * @mtd: MTD device structure
290 * @buf: temporary buffer
291 * @td: descriptor for the bad block table
292 * @md: descriptor for the bad block table mirror
294 * Read the bad block table(s) for all chips starting at a given page
295 * We assume that the bbt bits are in consecutive order.
298 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
299 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
301 struct nand_chip
*this = mtd
->priv
;
303 /* Read the primary version, if available */
304 if (td
->options
& NAND_BBT_VERSION
) {
305 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
307 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
308 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
309 td
->pages
[0], td
->version
[0]);
312 /* Read the mirror version, if available */
313 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
314 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
316 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
317 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
318 md
->pages
[0], md
->version
[0]);
324 * Scan a given block full
326 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
327 loff_t offs
, uint8_t *buf
, size_t readlen
,
328 int scanlen
, int len
)
332 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
336 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
337 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
344 * Scan a given block partially
346 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
347 loff_t offs
, uint8_t *buf
, int len
)
349 struct mtd_oob_ops ops
;
352 ops
.ooblen
= mtd
->oobsize
;
356 ops
.mode
= MTD_OOB_PLACE
;
358 for (j
= 0; j
< len
; j
++) {
360 * Read the full oob until read_oob is fixed to
361 * handle single byte reads for 16 bit
364 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
368 if (check_short_pattern(buf
, bd
))
371 offs
+= mtd
->writesize
;
377 * create_bbt - [GENERIC] Create a bad block table by scanning the device
378 * @mtd: MTD device structure
379 * @buf: temporary buffer
380 * @bd: descriptor for the good/bad block search pattern
381 * @chip: create the table for a specific chip, -1 read all chips.
382 * Applies only if NAND_BBT_PERCHIP option is set
384 * Create a bad block table by scanning the device
385 * for the given good/bad block identify pattern
387 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
388 struct nand_bbt_descr
*bd
, int chip
)
390 struct nand_chip
*this = mtd
->priv
;
391 int i
, numblocks
, len
, scanlen
;
396 printk(KERN_INFO
"Scanning device for bad blocks\n");
398 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
399 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
401 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
407 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
408 /* We need only read few bytes from the OOB area */
412 /* Full page content should be read */
413 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
414 readlen
= len
* mtd
->writesize
;
418 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
419 * below as it makes shifting and masking less painful */
420 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
424 if (chip
>= this->numchips
) {
425 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
426 chip
+ 1, this->numchips
);
429 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
430 startblock
= chip
* numblocks
;
431 numblocks
+= startblock
;
432 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
435 for (i
= startblock
; i
< numblocks
;) {
438 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
439 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
442 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
448 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
449 printk(KERN_WARNING
"Bad eraseblock %d at 0x%012llx\n",
450 i
>> 1, (unsigned long long)from
);
451 mtd
->ecc_stats
.badblocks
++;
455 from
+= (1 << this->bbt_erase_shift
);
461 * search_bbt - [GENERIC] scan the device for a specific bad block table
462 * @mtd: MTD device structure
463 * @buf: temporary buffer
464 * @td: descriptor for the bad block table
466 * Read the bad block table by searching for a given ident pattern.
467 * Search is preformed either from the beginning up or from the end of
468 * the device downwards. The search starts always at the start of a
470 * If the option NAND_BBT_PERCHIP is given, each chip is searched
471 * for a bbt, which contains the bad block information of this chip.
472 * This is necessary to provide support for certain DOC devices.
474 * The bbt ident pattern resides in the oob area of the first page
477 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
479 struct nand_chip
*this = mtd
->priv
;
481 int bits
, startblock
, block
, dir
;
482 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
484 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
486 /* Search direction top -> down ? */
487 if (td
->options
& NAND_BBT_LASTBLOCK
) {
488 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
495 /* Do we have a bbt per chip ? */
496 if (td
->options
& NAND_BBT_PERCHIP
) {
497 chips
= this->numchips
;
498 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
499 startblock
&= bbtblocks
- 1;
502 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
505 /* Number of bits for each erase block in the bbt */
506 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
508 for (i
= 0; i
< chips
; i
++) {
509 /* Reset version information */
512 /* Scan the maximum number of blocks */
513 for (block
= 0; block
< td
->maxblocks
; block
++) {
515 int actblock
= startblock
+ dir
* block
;
516 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
518 /* Read first page */
519 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
520 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
521 td
->pages
[i
] = actblock
<< blocktopage
;
522 if (td
->options
& NAND_BBT_VERSION
) {
523 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
528 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
530 /* Check, if we found a bbt for each requested chip */
531 for (i
= 0; i
< chips
; i
++) {
532 if (td
->pages
[i
] == -1)
533 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
535 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
542 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
543 * @mtd: MTD device structure
544 * @buf: temporary buffer
545 * @td: descriptor for the bad block table
546 * @md: descriptor for the bad block table mirror
548 * Search and read the bad block table(s)
550 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
552 /* Search the primary table */
553 search_bbt(mtd
, buf
, td
);
555 /* Search the mirror table */
557 search_bbt(mtd
, buf
, md
);
559 /* Force result check */
564 * write_bbt - [GENERIC] (Re)write the bad block table
566 * @mtd: MTD device structure
567 * @buf: temporary buffer
568 * @td: descriptor for the bad block table
569 * @md: descriptor for the bad block table mirror
570 * @chipsel: selector for a specific chip, -1 for all
572 * (Re)write the bad block table
575 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
576 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
579 struct nand_chip
*this = mtd
->priv
;
580 struct erase_info einfo
;
581 int i
, j
, res
, chip
= 0;
582 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
583 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
585 uint8_t rcode
= td
->reserved_block_code
;
586 size_t retlen
, len
= 0;
588 struct mtd_oob_ops ops
;
590 ops
.ooblen
= mtd
->oobsize
;
593 ops
.mode
= MTD_OOB_PLACE
;
597 /* Write bad block table per chip rather than per device ? */
598 if (td
->options
& NAND_BBT_PERCHIP
) {
599 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
600 /* Full device write or specific chip ? */
602 nrchips
= this->numchips
;
604 nrchips
= chipsel
+ 1;
608 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
612 /* Loop through the chips */
613 for (; chip
< nrchips
; chip
++) {
615 /* There was already a version of the table, reuse the page
616 * This applies for absolute placement too, as we have the
617 * page nr. in td->pages.
619 if (td
->pages
[chip
] != -1) {
620 page
= td
->pages
[chip
];
624 /* Automatic placement of the bad block table */
625 /* Search direction top -> down ? */
626 if (td
->options
& NAND_BBT_LASTBLOCK
) {
627 startblock
= numblocks
* (chip
+ 1) - 1;
630 startblock
= chip
* numblocks
;
634 for (i
= 0; i
< td
->maxblocks
; i
++) {
635 int block
= startblock
+ dir
* i
;
636 /* Check, if the block is bad */
637 switch ((this->bbt
[block
>> 2] >>
638 (2 * (block
& 0x03))) & 0x03) {
644 (this->bbt_erase_shift
- this->page_shift
);
645 /* Check, if the block is used by the mirror table */
646 if (!md
|| md
->pages
[chip
] != page
)
649 printk(KERN_ERR
"No space left to write bad block table\n");
653 /* Set up shift count and masks for the flash table */
654 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
657 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
660 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
663 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
666 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
669 default: return -EINVAL
;
672 bbtoffs
= chip
* (numblocks
>> 2);
674 to
= ((loff_t
) page
) << this->page_shift
;
676 /* Must we save the block contents ? */
677 if (td
->options
& NAND_BBT_SAVECONTENT
) {
678 /* Make it block aligned */
679 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
680 len
= 1 << this->bbt_erase_shift
;
681 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
684 printk(KERN_INFO
"nand_bbt: Error "
685 "reading block for writing "
686 "the bad block table\n");
689 printk(KERN_WARNING
"nand_bbt: ECC error "
690 "while reading block for writing "
691 "bad block table\n");
694 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
695 ops
.oobbuf
= &buf
[len
];
696 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
697 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
700 /* Calc the byte offset in the buffer */
701 pageoffs
= page
- (int)(to
>> this->page_shift
);
702 offs
= pageoffs
<< this->page_shift
;
703 /* Preset the bbt area with 0xff */
704 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
705 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
709 len
= (size_t) (numblocks
>> sft
);
710 /* Make it page aligned ! */
711 len
= (len
+ (mtd
->writesize
- 1)) &
712 ~(mtd
->writesize
- 1);
713 /* Preset the buffer with 0xff */
714 memset(buf
, 0xff, len
+
715 (len
>> this->page_shift
)* mtd
->oobsize
);
718 /* Pattern is located in oob area of first page */
719 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
722 if (td
->options
& NAND_BBT_VERSION
)
723 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
725 /* walk through the memory table */
726 for (i
= 0; i
< numblocks
;) {
728 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
729 for (j
= 0; j
< 4; j
++, i
++) {
730 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
731 /* Do not store the reserved bbt blocks ! */
732 buf
[offs
+ (i
>> sft
)] &=
733 ~(msk
[dat
& 0x03] << sftcnt
);
738 memset(&einfo
, 0, sizeof(einfo
));
741 einfo
.len
= 1 << this->bbt_erase_shift
;
742 res
= nand_erase_nand(mtd
, &einfo
, 1);
746 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
750 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, version "
751 "0x%02X\n", (unsigned long long)to
, td
->version
[chip
]);
753 /* Mark it as used */
754 td
->pages
[chip
] = page
;
760 "nand_bbt: Error while writing bad block table %d\n", res
);
765 * nand_memory_bbt - [GENERIC] create a memory based bad block table
766 * @mtd: MTD device structure
767 * @bd: descriptor for the good/bad block search pattern
769 * The function creates a memory based bbt by scanning the device
770 * for manufacturer / software marked good / bad blocks
772 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
774 struct nand_chip
*this = mtd
->priv
;
776 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
777 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
781 * check_create - [GENERIC] create and write bbt(s) if necessary
782 * @mtd: MTD device structure
783 * @buf: temporary buffer
784 * @bd: descriptor for the good/bad block search pattern
786 * The function checks the results of the previous call to read_bbt
787 * and creates / updates the bbt(s) if necessary
788 * Creation is necessary if no bbt was found for the chip/device
789 * Update is necessary if one of the tables is missing or the
790 * version nr. of one table is less than the other
792 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
794 int i
, chips
, writeops
, chipsel
, res
;
795 struct nand_chip
*this = mtd
->priv
;
796 struct nand_bbt_descr
*td
= this->bbt_td
;
797 struct nand_bbt_descr
*md
= this->bbt_md
;
798 struct nand_bbt_descr
*rd
, *rd2
;
800 /* Do we have a bbt per chip ? */
801 if (td
->options
& NAND_BBT_PERCHIP
)
802 chips
= this->numchips
;
806 for (i
= 0; i
< chips
; i
++) {
810 /* Per chip or per device ? */
811 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
812 /* Mirrored table avilable ? */
814 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
819 if (td
->pages
[i
] == -1) {
821 td
->version
[i
] = md
->version
[i
];
826 if (md
->pages
[i
] == -1) {
828 md
->version
[i
] = td
->version
[i
];
833 if (td
->version
[i
] == md
->version
[i
]) {
835 if (!(td
->options
& NAND_BBT_VERSION
))
840 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
842 md
->version
[i
] = td
->version
[i
];
846 td
->version
[i
] = md
->version
[i
];
853 if (td
->pages
[i
] == -1) {
861 /* Create the bad block table by scanning the device ? */
862 if (!(td
->options
& NAND_BBT_CREATE
))
865 /* Create the table in memory by scanning the chip(s) */
866 create_bbt(mtd
, buf
, bd
, chipsel
);
872 /* read back first ? */
874 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
875 /* If they weren't versioned, read both. */
877 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
879 /* Write the bad block table to the device ? */
880 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
881 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
886 /* Write the mirror bad block table to the device ? */
887 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
888 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
897 * mark_bbt_regions - [GENERIC] mark the bad block table regions
898 * @mtd: MTD device structure
899 * @td: bad block table descriptor
901 * The bad block table regions are marked as "bad" to prevent
902 * accidental erasures / writes. The regions are identified by
905 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
907 struct nand_chip
*this = mtd
->priv
;
908 int i
, j
, chips
, block
, nrblocks
, update
;
909 uint8_t oldval
, newval
;
911 /* Do we have a bbt per chip ? */
912 if (td
->options
& NAND_BBT_PERCHIP
) {
913 chips
= this->numchips
;
914 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
917 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
920 for (i
= 0; i
< chips
; i
++) {
921 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
922 !(td
->options
& NAND_BBT_WRITE
)) {
923 if (td
->pages
[i
] == -1)
925 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
927 oldval
= this->bbt
[(block
>> 3)];
928 newval
= oldval
| (0x2 << (block
& 0x06));
929 this->bbt
[(block
>> 3)] = newval
;
930 if ((oldval
!= newval
) && td
->reserved_block_code
)
931 nand_update_bbt(mtd
, (loff_t
)block
<< (this->bbt_erase_shift
- 1));
935 if (td
->options
& NAND_BBT_LASTBLOCK
)
936 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
938 block
= i
* nrblocks
;
940 for (j
= 0; j
< td
->maxblocks
; j
++) {
941 oldval
= this->bbt
[(block
>> 3)];
942 newval
= oldval
| (0x2 << (block
& 0x06));
943 this->bbt
[(block
>> 3)] = newval
;
944 if (oldval
!= newval
)
948 /* If we want reserved blocks to be recorded to flash, and some
949 new ones have been marked, then we need to update the stored
950 bbts. This should only happen once. */
951 if (update
&& td
->reserved_block_code
)
952 nand_update_bbt(mtd
, (loff_t
)(block
- 2) << (this->bbt_erase_shift
- 1));
957 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
958 * @mtd: MTD device structure
959 * @bd: descriptor for the good/bad block search pattern
961 * The function checks, if a bad block table(s) is/are already
962 * available. If not it scans the device for manufacturer
963 * marked good / bad blocks and writes the bad block table(s) to
964 * the selected place.
966 * The bad block table memory is allocated here. It must be freed
967 * by calling the nand_free_bbt function.
970 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
972 struct nand_chip
*this = mtd
->priv
;
975 struct nand_bbt_descr
*td
= this->bbt_td
;
976 struct nand_bbt_descr
*md
= this->bbt_md
;
978 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
979 /* Allocate memory (2bit per block) and clear the memory bad block table */
980 this->bbt
= kzalloc(len
, GFP_KERNEL
);
982 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
986 /* If no primary table decriptor is given, scan the device
987 * to build a memory based bad block table
990 if ((res
= nand_memory_bbt(mtd
, bd
))) {
991 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
998 /* Allocate a temporary buffer for one eraseblock incl. oob */
999 len
= (1 << this->bbt_erase_shift
);
1000 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1003 printk(KERN_ERR
"nand_bbt: Out of memory\n");
1009 /* Is the bbt at a given page ? */
1010 if (td
->options
& NAND_BBT_ABSPAGE
) {
1011 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1013 /* Search the bad block table using a pattern in oob */
1014 res
= search_read_bbts(mtd
, buf
, td
, md
);
1018 res
= check_create(mtd
, buf
, bd
);
1020 /* Prevent the bbt regions from erasing / writing */
1021 mark_bbt_region(mtd
, td
);
1023 mark_bbt_region(mtd
, md
);
1030 * nand_update_bbt - [NAND Interface] update bad block table(s)
1031 * @mtd: MTD device structure
1032 * @offs: the offset of the newly marked block
1034 * The function updates the bad block table(s)
1036 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1038 struct nand_chip
*this = mtd
->priv
;
1039 int len
, res
= 0, writeops
= 0;
1042 struct nand_bbt_descr
*td
= this->bbt_td
;
1043 struct nand_bbt_descr
*md
= this->bbt_md
;
1045 if (!this->bbt
|| !td
)
1048 /* Allocate a temporary buffer for one eraseblock incl. oob */
1049 len
= (1 << this->bbt_erase_shift
);
1050 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1051 buf
= kmalloc(len
, GFP_KERNEL
);
1053 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1057 writeops
= md
!= NULL
? 0x03 : 0x01;
1059 /* Do we have a bbt per chip ? */
1060 if (td
->options
& NAND_BBT_PERCHIP
) {
1061 chip
= (int)(offs
>> this->chip_shift
);
1068 td
->version
[chip
]++;
1070 md
->version
[chip
]++;
1072 /* Write the bad block table to the device ? */
1073 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1074 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1078 /* Write the mirror bad block table to the device ? */
1079 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1080 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1088 /* Define some generic bad / good block scan pattern which are used
1089 * while scanning a device for factory marked good / bad blocks. */
1090 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1092 static struct nand_bbt_descr smallpage_memorybased
= {
1093 .options
= NAND_BBT_SCAN2NDPAGE
,
1096 .pattern
= scan_ff_pattern
1099 static struct nand_bbt_descr largepage_memorybased
= {
1103 .pattern
= scan_ff_pattern
1106 static struct nand_bbt_descr smallpage_flashbased
= {
1107 .options
= NAND_BBT_SCAN2NDPAGE
,
1110 .pattern
= scan_ff_pattern
1113 static struct nand_bbt_descr largepage_flashbased
= {
1114 .options
= NAND_BBT_SCAN2NDPAGE
,
1117 .pattern
= scan_ff_pattern
1120 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1122 static struct nand_bbt_descr agand_flashbased
= {
1123 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1126 .pattern
= scan_agand_pattern
1129 /* Generic flash bbt decriptors
1131 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1132 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1134 static struct nand_bbt_descr bbt_main_descr
= {
1135 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1136 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1141 .pattern
= bbt_pattern
1144 static struct nand_bbt_descr bbt_mirror_descr
= {
1145 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1146 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1151 .pattern
= mirror_pattern
1155 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1156 * @mtd: MTD device structure
1158 * This function selects the default bad block table
1159 * support for the device and calls the nand_scan_bbt function
1162 int nand_default_bbt(struct mtd_info
*mtd
)
1164 struct nand_chip
*this = mtd
->priv
;
1166 /* Default for AG-AND. We must use a flash based
1167 * bad block table as the devices have factory marked
1168 * _good_ blocks. Erasing those blocks leads to loss
1169 * of the good / bad information, so we _must_ store
1170 * this information in a good / bad table during
1173 if (this->options
& NAND_IS_AND
) {
1174 /* Use the default pattern descriptors */
1175 if (!this->bbt_td
) {
1176 this->bbt_td
= &bbt_main_descr
;
1177 this->bbt_md
= &bbt_mirror_descr
;
1179 this->options
|= NAND_USE_FLASH_BBT
;
1180 return nand_scan_bbt(mtd
, &agand_flashbased
);
1183 /* Is a flash based bad block table requested ? */
1184 if (this->options
& NAND_USE_FLASH_BBT
) {
1185 /* Use the default pattern descriptors */
1186 if (!this->bbt_td
) {
1187 this->bbt_td
= &bbt_main_descr
;
1188 this->bbt_md
= &bbt_mirror_descr
;
1190 if (!this->badblock_pattern
) {
1191 this->badblock_pattern
= (mtd
->writesize
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1194 this->bbt_td
= NULL
;
1195 this->bbt_md
= NULL
;
1196 if (!this->badblock_pattern
) {
1197 this->badblock_pattern
= (mtd
->writesize
> 512) ?
1198 &largepage_memorybased
: &smallpage_memorybased
;
1201 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1205 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1206 * @mtd: MTD device structure
1207 * @offs: offset in the device
1208 * @allowbbt: allow access to bad block table region
1211 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1213 struct nand_chip
*this = mtd
->priv
;
1217 /* Get block number * 2 */
1218 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1219 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1221 DEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1222 (unsigned int)offs
, block
>> 1, res
);
1230 return allowbbt
? 0 : 1;
1235 EXPORT_SYMBOL(nand_scan_bbt
);
1236 EXPORT_SYMBOL(nand_default_bbt
);