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22 * If one of the bbt's is out of date or does not exist it is (re)created.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>
63 #include <linux/slab.h>
64 #include <linux/types.h>
65 #include <linux/mtd/mtd.h>
66 #include <linux/mtd/nand.h>
67 #include <linux/mtd/nand_ecc.h>
68 #include <linux/mtd/compatmac.h>
69 #include <linux/bitops.h>
70 #include <linux/delay.h>
71 #include <linux/vmalloc.h>
75 * check_pattern - [GENERIC] check if a pattern is in the buffer
76 * @buf: the buffer to search
77 * @len: the length of buffer to search
78 * @paglen: the pagelength
79 * @td: search pattern descriptor
81 * Check for a pattern at the given place. Used to search bad block
82 * tables and good / bad block identifiers.
83 * If the SCAN_EMPTY option is set then check, if all bytes except the
84 * pattern area contain 0xff
87 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
92 end
= paglen
+ td
->offs
;
93 if (td
->options
& NAND_BBT_SCANEMPTY
) {
94 for (i
= 0; i
< end
; i
++) {
101 /* Compare the pattern */
102 for (i
= 0; i
< td
->len
; i
++) {
103 if (p
[i
] != td
->pattern
[i
])
107 if (td
->options
& NAND_BBT_SCANEMPTY
) {
110 for (i
= end
; i
< len
; i
++) {
119 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
120 * @buf: the buffer to search
121 * @td: search pattern descriptor
123 * Check for a pattern at the given place. Used to search bad block
124 * tables and good / bad block identifiers. Same as check_pattern, but
125 * no optional empty check
128 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
133 /* Compare the pattern */
134 for (i
= 0; i
< td
->len
; i
++) {
135 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
142 * read_bbt - [GENERIC] Read the bad block table starting from page
143 * @mtd: MTD device structure
144 * @buf: temporary buffer
145 * @page: the starting page
146 * @num: the number of bbt descriptors to read
147 * @bits: number of bits per block
148 * @offs: offset in the memory table
149 * @reserved_block_code: Pattern to identify reserved blocks
151 * Read the bad block table starting from page.
154 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
155 int bits
, int offs
, int reserved_block_code
)
157 int res
, i
, j
, act
= 0;
158 struct nand_chip
*this = mtd
->priv
;
159 size_t retlen
, len
, totlen
;
161 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
163 totlen
= (num
* bits
) >> 3;
164 from
= ((loff_t
) page
) << this->page_shift
;
167 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
168 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
171 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
174 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
178 for (i
= 0; i
< len
; i
++) {
179 uint8_t dat
= buf
[i
];
180 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
181 uint8_t tmp
= (dat
>> j
) & msk
;
184 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
185 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
186 (loff_t
)((offs
<< 2) +
188 this->bbt_erase_shift
);
189 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
190 mtd
->ecc_stats
.bbtblocks
++;
193 /* Leave it for now, if its matured we can move this
194 * message to MTD_DEBUG_LEVEL0 */
195 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%012llx\n",
196 (loff_t
)((offs
<< 2) + (act
>> 1)) <<
197 this->bbt_erase_shift
);
198 /* Factory marked bad or worn out ? */
200 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
202 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
203 mtd
->ecc_stats
.badblocks
++;
213 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
214 * @mtd: MTD device structure
215 * @buf: temporary buffer
216 * @td: descriptor for the bad block table
217 * @chip: read the table for a specific chip, -1 read all chips.
218 * Applies only if NAND_BBT_PERCHIP option is set
220 * Read the bad block table for all chips starting at a given page
221 * We assume that the bbt bits are in consecutive order.
223 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
225 struct nand_chip
*this = mtd
->priv
;
229 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
230 if (td
->options
& NAND_BBT_PERCHIP
) {
232 for (i
= 0; i
< this->numchips
; i
++) {
233 if (chip
== -1 || chip
== i
)
234 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
237 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
240 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
248 * Scan read raw data from flash
250 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
253 struct mtd_oob_ops ops
;
255 ops
.mode
= MTD_OOB_RAW
;
257 ops
.ooblen
= mtd
->oobsize
;
262 return mtd
->read_oob(mtd
, offs
, &ops
);
266 * Scan write data with oob to flash
268 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
269 uint8_t *buf
, uint8_t *oob
)
271 struct mtd_oob_ops ops
;
273 ops
.mode
= MTD_OOB_PLACE
;
275 ops
.ooblen
= mtd
->oobsize
;
280 return mtd
->write_oob(mtd
, offs
, &ops
);
284 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
285 * @mtd: MTD device structure
286 * @buf: temporary buffer
287 * @td: descriptor for the bad block table
288 * @md: descriptor for the bad block table mirror
290 * Read the bad block table(s) for all chips starting at a given page
291 * We assume that the bbt bits are in consecutive order.
294 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
295 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
297 struct nand_chip
*this = mtd
->priv
;
299 /* Read the primary version, if available */
300 if (td
->options
& NAND_BBT_VERSION
) {
301 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] <<
302 this->page_shift
, mtd
->writesize
);
303 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
304 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
305 td
->pages
[0], td
->version
[0]);
308 /* Read the mirror version, if available */
309 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
310 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] <<
311 this->page_shift
, mtd
->writesize
);
312 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
313 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
314 md
->pages
[0], md
->version
[0]);
320 * Scan a given block full
322 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
323 loff_t offs
, uint8_t *buf
, size_t readlen
,
324 int scanlen
, int len
)
328 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
332 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
333 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
340 * Scan a given block partially
342 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
343 loff_t offs
, uint8_t *buf
, int len
)
345 struct mtd_oob_ops ops
;
348 ops
.ooblen
= mtd
->oobsize
;
352 ops
.mode
= MTD_OOB_PLACE
;
354 for (j
= 0; j
< len
; j
++) {
356 * Read the full oob until read_oob is fixed to
357 * handle single byte reads for 16 bit
360 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
364 if (check_short_pattern(buf
, bd
))
367 offs
+= mtd
->writesize
;
373 * create_bbt - [GENERIC] Create a bad block table by scanning the device
374 * @mtd: MTD device structure
375 * @buf: temporary buffer
376 * @bd: descriptor for the good/bad block search pattern
377 * @chip: create the table for a specific chip, -1 read all chips.
378 * Applies only if NAND_BBT_PERCHIP option is set
380 * Create a bad block table by scanning the device
381 * for the given good/bad block identify pattern
383 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
384 struct nand_bbt_descr
*bd
, int chip
)
386 struct nand_chip
*this = mtd
->priv
;
387 int i
, numblocks
, len
, scanlen
;
392 MTDDEBUG (MTD_DEBUG_LEVEL0
, "Scanning device for bad blocks\n");
394 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
395 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
397 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
403 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
404 /* We need only read few bytes from the OOB area */
408 /* Full page content should be read */
409 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
410 readlen
= len
* mtd
->writesize
;
414 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
415 * below as it makes shifting and masking less painful */
416 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
420 if (chip
>= this->numchips
) {
421 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
422 chip
+ 1, this->numchips
);
425 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
426 startblock
= chip
* numblocks
;
427 numblocks
+= startblock
;
428 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
431 for (i
= startblock
; i
< numblocks
;) {
434 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
435 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
438 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
444 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
445 MTDDEBUG (MTD_DEBUG_LEVEL0
,
446 "Bad eraseblock %d at 0x%012llx\n",
447 i
>> 1, (unsigned long long)from
);
448 mtd
->ecc_stats
.badblocks
++;
452 from
+= (1 << this->bbt_erase_shift
);
458 * search_bbt - [GENERIC] scan the device for a specific bad block table
459 * @mtd: MTD device structure
460 * @buf: temporary buffer
461 * @td: descriptor for the bad block table
463 * Read the bad block table by searching for a given ident pattern.
464 * Search is preformed either from the beginning up or from the end of
465 * the device downwards. The search starts always at the start of a
467 * If the option NAND_BBT_PERCHIP is given, each chip is searched
468 * for a bbt, which contains the bad block information of this chip.
469 * This is necessary to provide support for certain DOC devices.
471 * The bbt ident pattern resides in the oob area of the first page
474 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
476 struct nand_chip
*this = mtd
->priv
;
478 int bits
, startblock
, block
, dir
;
479 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
481 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
483 /* Search direction top -> down ? */
484 if (td
->options
& NAND_BBT_LASTBLOCK
) {
485 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
492 /* Do we have a bbt per chip ? */
493 if (td
->options
& NAND_BBT_PERCHIP
) {
494 chips
= this->numchips
;
495 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
496 startblock
&= bbtblocks
- 1;
499 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
502 /* Number of bits for each erase block in the bbt */
503 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
505 for (i
= 0; i
< chips
; i
++) {
506 /* Reset version information */
509 /* Scan the maximum number of blocks */
510 for (block
= 0; block
< td
->maxblocks
; block
++) {
512 int actblock
= startblock
+ dir
* block
;
513 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
515 /* Read first page */
516 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
517 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
518 td
->pages
[i
] = actblock
<< blocktopage
;
519 if (td
->options
& NAND_BBT_VERSION
) {
520 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
525 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
527 /* Check, if we found a bbt for each requested chip */
528 for (i
= 0; i
< chips
; i
++) {
529 if (td
->pages
[i
] == -1)
530 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
532 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
539 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
540 * @mtd: MTD device structure
541 * @buf: temporary buffer
542 * @td: descriptor for the bad block table
543 * @md: descriptor for the bad block table mirror
545 * Search and read the bad block table(s)
547 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
549 /* Search the primary table */
550 search_bbt(mtd
, buf
, td
);
552 /* Search the mirror table */
554 search_bbt(mtd
, buf
, md
);
556 /* Force result check */
561 * write_bbt - [GENERIC] (Re)write the bad block table
563 * @mtd: MTD device structure
564 * @buf: temporary buffer
565 * @td: descriptor for the bad block table
566 * @md: descriptor for the bad block table mirror
567 * @chipsel: selector for a specific chip, -1 for all
569 * (Re)write the bad block table
572 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
573 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
576 struct nand_chip
*this = mtd
->priv
;
577 struct erase_info einfo
;
578 int i
, j
, res
, chip
= 0;
579 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
580 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
582 uint8_t rcode
= td
->reserved_block_code
;
583 size_t retlen
, len
= 0;
585 struct mtd_oob_ops ops
;
587 ops
.ooblen
= mtd
->oobsize
;
590 ops
.mode
= MTD_OOB_PLACE
;
594 /* Write bad block table per chip rather than per device ? */
595 if (td
->options
& NAND_BBT_PERCHIP
) {
596 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
597 /* Full device write or specific chip ? */
599 nrchips
= this->numchips
;
601 nrchips
= chipsel
+ 1;
605 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
609 /* Loop through the chips */
610 for (; chip
< nrchips
; chip
++) {
612 /* There was already a version of the table, reuse the page
613 * This applies for absolute placement too, as we have the
614 * page nr. in td->pages.
616 if (td
->pages
[chip
] != -1) {
617 page
= td
->pages
[chip
];
621 /* Automatic placement of the bad block table */
622 /* Search direction top -> down ? */
623 if (td
->options
& NAND_BBT_LASTBLOCK
) {
624 startblock
= numblocks
* (chip
+ 1) - 1;
627 startblock
= chip
* numblocks
;
631 for (i
= 0; i
< td
->maxblocks
; i
++) {
632 int block
= startblock
+ dir
* i
;
633 /* Check, if the block is bad */
634 switch ((this->bbt
[block
>> 2] >>
635 (2 * (block
& 0x03))) & 0x03) {
641 (this->bbt_erase_shift
- this->page_shift
);
642 /* Check, if the block is used by the mirror table */
643 if (!md
|| md
->pages
[chip
] != page
)
646 printk(KERN_ERR
"No space left to write bad block table\n");
650 /* Set up shift count and masks for the flash table */
651 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
654 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
657 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
660 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
663 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
666 default: return -EINVAL
;
669 bbtoffs
= chip
* (numblocks
>> 2);
671 to
= ((loff_t
) page
) << this->page_shift
;
673 /* Must we save the block contents ? */
674 if (td
->options
& NAND_BBT_SAVECONTENT
) {
675 /* Make it block aligned */
676 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
677 len
= 1 << this->bbt_erase_shift
;
678 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
681 printk(KERN_INFO
"nand_bbt: Error "
682 "reading block for writing "
683 "the bad block table\n");
686 printk(KERN_WARNING
"nand_bbt: ECC error "
687 "while reading block for writing "
688 "bad block table\n");
691 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
692 ops
.oobbuf
= &buf
[len
];
693 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
694 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
697 /* Calc the byte offset in the buffer */
698 pageoffs
= page
- (int)(to
>> this->page_shift
);
699 offs
= pageoffs
<< this->page_shift
;
700 /* Preset the bbt area with 0xff */
701 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
702 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
706 len
= (size_t) (numblocks
>> sft
);
707 /* Make it page aligned ! */
708 len
= (len
+ (mtd
->writesize
- 1)) &
709 ~(mtd
->writesize
- 1);
710 /* Preset the buffer with 0xff */
711 memset(buf
, 0xff, len
+
712 (len
>> this->page_shift
)* mtd
->oobsize
);
715 /* Pattern is located in oob area of first page */
716 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
719 if (td
->options
& NAND_BBT_VERSION
)
720 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
722 /* walk through the memory table */
723 for (i
= 0; i
< numblocks
;) {
725 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
726 for (j
= 0; j
< 4; j
++, i
++) {
727 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
728 /* Do not store the reserved bbt blocks ! */
729 buf
[offs
+ (i
>> sft
)] &=
730 ~(msk
[dat
& 0x03] << sftcnt
);
735 memset(&einfo
, 0, sizeof(einfo
));
738 einfo
.len
= 1 << this->bbt_erase_shift
;
739 res
= nand_erase_nand(mtd
, &einfo
, 1);
743 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
747 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, "
748 "version 0x%02X\n", (unsigned long long)to
,
751 /* Mark it as used */
752 td
->pages
[chip
] = page
;
758 "nand_bbt: Error while writing bad block table %d\n", res
);
763 * nand_memory_bbt - [GENERIC] create a memory based bad block table
764 * @mtd: MTD device structure
765 * @bd: descriptor for the good/bad block search pattern
767 * The function creates a memory based bbt by scanning the device
768 * for manufacturer / software marked good / bad blocks
770 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
772 struct nand_chip
*this = mtd
->priv
;
774 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
775 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
779 * check_create - [GENERIC] create and write bbt(s) if necessary
780 * @mtd: MTD device structure
781 * @buf: temporary buffer
782 * @bd: descriptor for the good/bad block search pattern
784 * The function checks the results of the previous call to read_bbt
785 * and creates / updates the bbt(s) if necessary
786 * Creation is necessary if no bbt was found for the chip/device
787 * Update is necessary if one of the tables is missing or the
788 * version nr. of one table is less than the other
790 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
792 int i
, chips
, writeops
, chipsel
, res
;
793 struct nand_chip
*this = mtd
->priv
;
794 struct nand_bbt_descr
*td
= this->bbt_td
;
795 struct nand_bbt_descr
*md
= this->bbt_md
;
796 struct nand_bbt_descr
*rd
, *rd2
;
798 /* Do we have a bbt per chip ? */
799 if (td
->options
& NAND_BBT_PERCHIP
)
800 chips
= this->numchips
;
804 for (i
= 0; i
< chips
; i
++) {
808 /* Per chip or per device ? */
809 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
810 /* Mirrored table avilable ? */
812 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
817 if (td
->pages
[i
] == -1) {
819 td
->version
[i
] = md
->version
[i
];
824 if (md
->pages
[i
] == -1) {
826 md
->version
[i
] = td
->version
[i
];
831 if (td
->version
[i
] == md
->version
[i
]) {
833 if (!(td
->options
& NAND_BBT_VERSION
))
838 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
840 md
->version
[i
] = td
->version
[i
];
844 td
->version
[i
] = md
->version
[i
];
851 if (td
->pages
[i
] == -1) {
859 /* Create the bad block table by scanning the device ? */
860 if (!(td
->options
& NAND_BBT_CREATE
))
863 /* Create the table in memory by scanning the chip(s) */
864 create_bbt(mtd
, buf
, bd
, chipsel
);
870 /* read back first ? */
872 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
873 /* If they weren't versioned, read both. */
875 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
877 /* Write the bad block table to the device ? */
878 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
879 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
884 /* Write the mirror bad block table to the device ? */
885 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
886 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
895 * mark_bbt_regions - [GENERIC] mark the bad block table regions
896 * @mtd: MTD device structure
897 * @td: bad block table descriptor
899 * The bad block table regions are marked as "bad" to prevent
900 * accidental erasures / writes. The regions are identified by
903 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
905 struct nand_chip
*this = mtd
->priv
;
906 int i
, j
, chips
, block
, nrblocks
, update
;
907 uint8_t oldval
, newval
;
909 /* Do we have a bbt per chip ? */
910 if (td
->options
& NAND_BBT_PERCHIP
) {
911 chips
= this->numchips
;
912 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
915 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
918 for (i
= 0; i
< chips
; i
++) {
919 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
920 !(td
->options
& NAND_BBT_WRITE
)) {
921 if (td
->pages
[i
] == -1)
923 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
925 oldval
= this->bbt
[(block
>> 3)];
926 newval
= oldval
| (0x2 << (block
& 0x06));
927 this->bbt
[(block
>> 3)] = newval
;
928 if ((oldval
!= newval
) && td
->reserved_block_code
)
929 nand_update_bbt(mtd
, (loff_t
)block
<<
930 (this->bbt_erase_shift
- 1));
934 if (td
->options
& NAND_BBT_LASTBLOCK
)
935 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
937 block
= i
* nrblocks
;
939 for (j
= 0; j
< td
->maxblocks
; j
++) {
940 oldval
= this->bbt
[(block
>> 3)];
941 newval
= oldval
| (0x2 << (block
& 0x06));
942 this->bbt
[(block
>> 3)] = newval
;
943 if (oldval
!= newval
)
947 /* If we want reserved blocks to be recorded to flash, and some
948 new ones have been marked, then we need to update the stored
949 bbts. This should only happen once. */
950 if (update
&& td
->reserved_block_code
)
951 nand_update_bbt(mtd
, (loff_t
)(block
- 2) <<
952 (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 MTDDEBUG (MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1222 "(block %d) 0x%02x\n", (unsigned int)offs
, res
, block
>> 1);
1230 return allowbbt
? 0 : 1;
1235 /* XXX U-BOOT XXX */
1237 EXPORT_SYMBOL(nand_scan_bbt
);
1238 EXPORT_SYMBOL(nand_default_bbt
);