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 no flash based BBT
17 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
18 * marked good / bad blocks. This information is used to create a memory BBT.
19 * Once a new bad block is discovered then the "factory" information is updated
21 * If a flash based BBT is specified then the function first tries to find the
22 * BBT on flash. If a BBT is found then the contents are read and the memory
23 * based BBT is created. If a mirrored BBT is selected then the mirror is
24 * searched too and the versions are compared. If the mirror has a greater
25 * version number than the mirror BBT is used to build the memory based BBT.
26 * If the tables are not versioned, then we "or" the bad block information.
27 * If one of the BBTs is out of date or does not exist it is (re)created.
28 * If no BBT exists at all then the device is scanned for factory marked
29 * good / bad blocks and the bad block tables are created.
31 * For manufacturer created BBTs like the one found on M-SYS DOC devices
32 * the BBT is searched and read but never created
34 * The auto generated bad block table is located in the last good blocks
35 * of the device. The table is mirrored, so it can be updated eventually.
36 * The table is marked in the OOB area with an ident pattern and a version
37 * number which indicates which of both tables is more up to date. If the NAND
38 * controller needs the complete OOB area for the ECC information then the
39 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
40 * course): it moves the ident pattern and the version byte into the data area
41 * and the OOB area will remain untouched.
43 * The table uses 2 bits per block
45 * 00b: block is factory marked bad
46 * 01b, 10b: block is marked bad due to wear
48 * The memory bad block table uses the following scheme:
50 * 01b: block is marked bad due to wear
51 * 10b: block is reserved (to protect the bbt area)
52 * 11b: block is factory marked bad
54 * Multichip devices like DOC store the bad block info per floor.
56 * Following assumptions are made:
57 * - bbts start at a page boundary, if autolocated on a block boundary
58 * - the space necessary for a bbt in FLASH does not exceed a block boundary
62 #include <linux/slab.h>
63 #include <linux/types.h>
64 #include <linux/mtd/mtd.h>
65 #include <linux/mtd/nand.h>
66 #include <linux/mtd/nand_ecc.h>
67 #include <linux/bitops.h>
68 #include <linux/delay.h>
69 #include <linux/vmalloc.h>
71 static int check_pattern_no_oob(uint8_t *buf
, struct nand_bbt_descr
*td
)
75 ret
= memcmp(buf
, td
->pattern
, td
->len
);
82 * check_pattern - [GENERIC] check if a pattern is in the buffer
83 * @buf: the buffer to search
84 * @len: the length of buffer to search
85 * @paglen: the pagelength
86 * @td: search pattern descriptor
88 * Check for a pattern at the given place. Used to search bad block
89 * tables and good / bad block identifiers.
90 * If the SCAN_EMPTY option is set then check, if all bytes except the
91 * pattern area contain 0xff
94 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
99 if (td
->options
& NAND_BBT_NO_OOB
)
100 return check_pattern_no_oob(buf
, td
);
102 end
= paglen
+ td
->offs
;
103 if (td
->options
& NAND_BBT_SCANEMPTY
) {
104 for (i
= 0; i
< end
; i
++) {
111 /* Compare the pattern */
112 for (i
= 0; i
< td
->len
; i
++) {
113 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
])
152 * add_marker_len - compute the length of the marker in data area
153 * @td: BBT descriptor used for computation
155 * The length will be 0 if the markeris located in OOB area.
157 static u32
add_marker_len(struct nand_bbt_descr
*td
)
161 if (!(td
->options
& NAND_BBT_NO_OOB
))
165 if (td
->options
& NAND_BBT_VERSION
)
171 * read_bbt - [GENERIC] Read the bad block table starting from page
172 * @mtd: MTD device structure
173 * @buf: temporary buffer
174 * @page: the starting page
175 * @num: the number of bbt descriptors to read
176 * @td: the bbt describtion table
177 * @offs: offset in the memory table
179 * Read the bad block table starting from page.
182 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
183 struct nand_bbt_descr
*td
, int offs
)
185 int res
, i
, j
, act
= 0;
186 struct nand_chip
*this = mtd
->priv
;
187 size_t retlen
, len
, totlen
;
189 int bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
190 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
192 int reserved_block_code
= td
->reserved_block_code
;
194 totlen
= (num
* bits
) >> 3;
195 marker_len
= add_marker_len(td
);
196 from
= ((loff_t
) page
) << this->page_shift
;
199 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
202 * In case the BBT marker is not in the OOB area it
203 * will be just in the first page.
209 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
212 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
215 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
219 for (i
= 0; i
< len
; i
++) {
220 uint8_t dat
= buf
[i
];
221 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
222 uint8_t tmp
= (dat
>> j
) & msk
;
225 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
226 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
227 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
228 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
229 mtd
->ecc_stats
.bbtblocks
++;
232 /* Leave it for now, if its matured we can move this
233 * message to MTD_DEBUG_LEVEL0 */
234 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%012llx\n",
235 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
236 /* Factory marked bad or worn out ? */
238 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
240 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
241 mtd
->ecc_stats
.badblocks
++;
251 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
252 * @mtd: MTD device structure
253 * @buf: temporary buffer
254 * @td: descriptor for the bad block table
255 * @chip: read the table for a specific chip, -1 read all chips.
256 * Applies only if NAND_BBT_PERCHIP option is set
258 * Read the bad block table for all chips starting at a given page
259 * We assume that the bbt bits are in consecutive order.
261 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
263 struct nand_chip
*this = mtd
->priv
;
266 if (td
->options
& NAND_BBT_PERCHIP
) {
268 for (i
= 0; i
< this->numchips
; i
++) {
269 if (chip
== -1 || chip
== i
)
270 res
= read_bbt(mtd
, buf
, td
->pages
[i
],
271 this->chipsize
>> this->bbt_erase_shift
,
275 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
278 res
= read_bbt(mtd
, buf
, td
->pages
[0],
279 mtd
->size
>> this->bbt_erase_shift
, td
, 0);
287 * BBT marker is in the first page, no OOB.
289 static int scan_read_raw_data(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
290 struct nand_bbt_descr
*td
)
296 if (td
->options
& NAND_BBT_VERSION
)
299 return mtd
->read(mtd
, offs
, len
, &retlen
, buf
);
303 * Scan read raw data from flash
305 static int scan_read_raw_oob(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
308 struct mtd_oob_ops ops
;
311 ops
.mode
= MTD_OOB_RAW
;
313 ops
.ooblen
= mtd
->oobsize
;
317 if (len
<= mtd
->writesize
) {
318 ops
.oobbuf
= buf
+ len
;
321 return mtd
->read_oob(mtd
, offs
, &ops
);
323 ops
.oobbuf
= buf
+ mtd
->writesize
;
325 ops
.len
= mtd
->writesize
;
326 res
= mtd
->read_oob(mtd
, offs
, &ops
);
332 buf
+= mtd
->oobsize
+ mtd
->writesize
;
333 len
-= mtd
->writesize
;
338 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
339 size_t len
, struct nand_bbt_descr
*td
)
341 if (td
->options
& NAND_BBT_NO_OOB
)
342 return scan_read_raw_data(mtd
, buf
, offs
, td
);
344 return scan_read_raw_oob(mtd
, buf
, offs
, len
);
348 * Scan write data with oob to flash
350 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
351 uint8_t *buf
, uint8_t *oob
)
353 struct mtd_oob_ops ops
;
355 ops
.mode
= MTD_OOB_PLACE
;
357 ops
.ooblen
= mtd
->oobsize
;
362 return mtd
->write_oob(mtd
, offs
, &ops
);
365 static u32
bbt_get_ver_offs(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
367 u32 ver_offs
= td
->veroffs
;
369 if (!(td
->options
& NAND_BBT_NO_OOB
))
370 ver_offs
+= mtd
->writesize
;
375 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
376 * @mtd: MTD device structure
377 * @buf: temporary buffer
378 * @td: descriptor for the bad block table
379 * @md: descriptor for the bad block table mirror
381 * Read the bad block table(s) for all chips starting at a given page
382 * We assume that the bbt bits are in consecutive order.
385 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
386 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
388 struct nand_chip
*this = mtd
->priv
;
390 /* Read the primary version, if available */
391 if (td
->options
& NAND_BBT_VERSION
) {
392 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
394 td
->version
[0] = buf
[bbt_get_ver_offs(mtd
, td
)];
395 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
396 td
->pages
[0], td
->version
[0]);
399 /* Read the mirror version, if available */
400 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
401 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
403 md
->version
[0] = buf
[bbt_get_ver_offs(mtd
, md
)];
404 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
405 md
->pages
[0], md
->version
[0]);
411 * Scan a given block full
413 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
414 loff_t offs
, uint8_t *buf
, size_t readlen
,
415 int scanlen
, int len
)
419 ret
= scan_read_raw_oob(mtd
, buf
, offs
, readlen
);
423 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
424 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
431 * Scan a given block partially
433 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
434 loff_t offs
, uint8_t *buf
, int len
)
436 struct mtd_oob_ops ops
;
439 ops
.ooblen
= mtd
->oobsize
;
443 ops
.mode
= MTD_OOB_PLACE
;
445 for (j
= 0; j
< len
; j
++) {
447 * Read the full oob until read_oob is fixed to
448 * handle single byte reads for 16 bit
451 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
455 if (check_short_pattern(buf
, bd
))
458 offs
+= mtd
->writesize
;
464 * create_bbt - [GENERIC] Create a bad block table by scanning the device
465 * @mtd: MTD device structure
466 * @buf: temporary buffer
467 * @bd: descriptor for the good/bad block search pattern
468 * @chip: create the table for a specific chip, -1 read all chips.
469 * Applies only if NAND_BBT_PERCHIP option is set
471 * Create a bad block table by scanning the device
472 * for the given good/bad block identify pattern
474 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
475 struct nand_bbt_descr
*bd
, int chip
)
477 struct nand_chip
*this = mtd
->priv
;
478 int i
, numblocks
, len
, scanlen
;
483 printk(KERN_INFO
"Scanning device for bad blocks\n");
485 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
486 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
487 else if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
492 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
493 /* We need only read few bytes from the OOB area */
497 /* Full page content should be read */
498 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
499 readlen
= len
* mtd
->writesize
;
503 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
504 * below as it makes shifting and masking less painful */
505 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
509 if (chip
>= this->numchips
) {
510 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
511 chip
+ 1, this->numchips
);
514 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
515 startblock
= chip
* numblocks
;
516 numblocks
+= startblock
;
517 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
520 if (this->bbt_options
& NAND_BBT_SCANLASTPAGE
)
521 from
+= mtd
->erasesize
- (mtd
->writesize
* len
);
523 for (i
= startblock
; i
< numblocks
;) {
526 BUG_ON(bd
->options
& NAND_BBT_NO_OOB
);
528 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
529 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
532 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
538 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
539 printk(KERN_WARNING
"Bad eraseblock %d at 0x%012llx\n",
540 i
>> 1, (unsigned long long)from
);
541 mtd
->ecc_stats
.badblocks
++;
545 from
+= (1 << this->bbt_erase_shift
);
551 * search_bbt - [GENERIC] scan the device for a specific bad block table
552 * @mtd: MTD device structure
553 * @buf: temporary buffer
554 * @td: descriptor for the bad block table
556 * Read the bad block table by searching for a given ident pattern.
557 * Search is preformed either from the beginning up or from the end of
558 * the device downwards. The search starts always at the start of a
560 * If the option NAND_BBT_PERCHIP is given, each chip is searched
561 * for a bbt, which contains the bad block information of this chip.
562 * This is necessary to provide support for certain DOC devices.
564 * The bbt ident pattern resides in the oob area of the first page
567 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
569 struct nand_chip
*this = mtd
->priv
;
571 int bits
, startblock
, block
, dir
;
572 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
574 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
576 /* Search direction top -> down ? */
577 if (td
->options
& NAND_BBT_LASTBLOCK
) {
578 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
585 /* Do we have a bbt per chip ? */
586 if (td
->options
& NAND_BBT_PERCHIP
) {
587 chips
= this->numchips
;
588 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
589 startblock
&= bbtblocks
- 1;
592 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
595 /* Number of bits for each erase block in the bbt */
596 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
598 for (i
= 0; i
< chips
; i
++) {
599 /* Reset version information */
602 /* Scan the maximum number of blocks */
603 for (block
= 0; block
< td
->maxblocks
; block
++) {
605 int actblock
= startblock
+ dir
* block
;
606 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
608 /* Read first page */
609 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
, td
);
610 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
611 td
->pages
[i
] = actblock
<< blocktopage
;
612 if (td
->options
& NAND_BBT_VERSION
) {
613 offs
= bbt_get_ver_offs(mtd
, td
);
614 td
->version
[i
] = buf
[offs
];
619 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
621 /* Check, if we found a bbt for each requested chip */
622 for (i
= 0; i
< chips
; i
++) {
623 if (td
->pages
[i
] == -1)
624 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
626 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
633 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
634 * @mtd: MTD device structure
635 * @buf: temporary buffer
636 * @td: descriptor for the bad block table
637 * @md: descriptor for the bad block table mirror
639 * Search and read the bad block table(s)
641 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
643 /* Search the primary table */
644 search_bbt(mtd
, buf
, td
);
646 /* Search the mirror table */
648 search_bbt(mtd
, buf
, md
);
650 /* Force result check */
655 * write_bbt - [GENERIC] (Re)write the bad block table
657 * @mtd: MTD device structure
658 * @buf: temporary buffer
659 * @td: descriptor for the bad block table
660 * @md: descriptor for the bad block table mirror
661 * @chipsel: selector for a specific chip, -1 for all
663 * (Re)write the bad block table
666 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
667 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
670 struct nand_chip
*this = mtd
->priv
;
671 struct erase_info einfo
;
672 int i
, j
, res
, chip
= 0;
673 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
674 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
676 uint8_t rcode
= td
->reserved_block_code
;
677 size_t retlen
, len
= 0;
679 struct mtd_oob_ops ops
;
681 ops
.ooblen
= mtd
->oobsize
;
684 ops
.mode
= MTD_OOB_PLACE
;
688 /* Write bad block table per chip rather than per device ? */
689 if (td
->options
& NAND_BBT_PERCHIP
) {
690 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
691 /* Full device write or specific chip ? */
693 nrchips
= this->numchips
;
695 nrchips
= chipsel
+ 1;
699 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
703 /* Loop through the chips */
704 for (; chip
< nrchips
; chip
++) {
706 /* There was already a version of the table, reuse the page
707 * This applies for absolute placement too, as we have the
708 * page nr. in td->pages.
710 if (td
->pages
[chip
] != -1) {
711 page
= td
->pages
[chip
];
715 /* Automatic placement of the bad block table */
716 /* Search direction top -> down ? */
717 if (td
->options
& NAND_BBT_LASTBLOCK
) {
718 startblock
= numblocks
* (chip
+ 1) - 1;
721 startblock
= chip
* numblocks
;
725 for (i
= 0; i
< td
->maxblocks
; i
++) {
726 int block
= startblock
+ dir
* i
;
727 /* Check, if the block is bad */
728 switch ((this->bbt
[block
>> 2] >>
729 (2 * (block
& 0x03))) & 0x03) {
735 (this->bbt_erase_shift
- this->page_shift
);
736 /* Check, if the block is used by the mirror table */
737 if (!md
|| md
->pages
[chip
] != page
)
740 printk(KERN_ERR
"No space left to write bad block table\n");
744 /* Set up shift count and masks for the flash table */
745 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
748 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
751 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
754 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
757 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
760 default: return -EINVAL
;
763 bbtoffs
= chip
* (numblocks
>> 2);
765 to
= ((loff_t
) page
) << this->page_shift
;
767 /* Must we save the block contents ? */
768 if (td
->options
& NAND_BBT_SAVECONTENT
) {
769 /* Make it block aligned */
770 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
771 len
= 1 << this->bbt_erase_shift
;
772 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
775 printk(KERN_INFO
"nand_bbt: Error "
776 "reading block for writing "
777 "the bad block table\n");
780 printk(KERN_WARNING
"nand_bbt: ECC error "
781 "while reading block for writing "
782 "bad block table\n");
785 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
786 ops
.oobbuf
= &buf
[len
];
787 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
788 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
791 /* Calc the byte offset in the buffer */
792 pageoffs
= page
- (int)(to
>> this->page_shift
);
793 offs
= pageoffs
<< this->page_shift
;
794 /* Preset the bbt area with 0xff */
795 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
796 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
798 } else if (td
->options
& NAND_BBT_NO_OOB
) {
801 /* the version byte */
802 if (td
->options
& NAND_BBT_VERSION
)
805 len
= (size_t) (numblocks
>> sft
);
807 /* Make it page aligned ! */
808 len
= ALIGN(len
, mtd
->writesize
);
809 /* Preset the buffer with 0xff */
810 memset(buf
, 0xff, len
);
811 /* Pattern is located at the begin of first page */
812 memcpy(buf
, td
->pattern
, td
->len
);
815 len
= (size_t) (numblocks
>> sft
);
816 /* Make it page aligned ! */
817 len
= ALIGN(len
, mtd
->writesize
);
818 /* Preset the buffer with 0xff */
819 memset(buf
, 0xff, len
+
820 (len
>> this->page_shift
)* mtd
->oobsize
);
823 /* Pattern is located in oob area of first page */
824 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
827 if (td
->options
& NAND_BBT_VERSION
)
828 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
830 /* walk through the memory table */
831 for (i
= 0; i
< numblocks
;) {
833 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
834 for (j
= 0; j
< 4; j
++, i
++) {
835 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
836 /* Do not store the reserved bbt blocks ! */
837 buf
[offs
+ (i
>> sft
)] &=
838 ~(msk
[dat
& 0x03] << sftcnt
);
843 memset(&einfo
, 0, sizeof(einfo
));
846 einfo
.len
= 1 << this->bbt_erase_shift
;
847 res
= nand_erase_nand(mtd
, &einfo
, 1);
851 res
= scan_write_bbt(mtd
, to
, len
, buf
,
852 td
->options
& NAND_BBT_NO_OOB
? NULL
:
857 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, version "
858 "0x%02X\n", (unsigned long long)to
, td
->version
[chip
]);
860 /* Mark it as used */
861 td
->pages
[chip
] = page
;
867 "nand_bbt: Error while writing bad block table %d\n", res
);
872 * nand_memory_bbt - [GENERIC] create a memory based bad block table
873 * @mtd: MTD device structure
874 * @bd: descriptor for the good/bad block search pattern
876 * The function creates a memory based bbt by scanning the device
877 * for manufacturer / software marked good / bad blocks
879 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
881 struct nand_chip
*this = mtd
->priv
;
883 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
884 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
888 * check_create - [GENERIC] create and write bbt(s) if necessary
889 * @mtd: MTD device structure
890 * @buf: temporary buffer
891 * @bd: descriptor for the good/bad block search pattern
893 * The function checks the results of the previous call to read_bbt
894 * and creates / updates the bbt(s) if necessary
895 * Creation is necessary if no bbt was found for the chip/device
896 * Update is necessary if one of the tables is missing or the
897 * version nr. of one table is less than the other
899 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
901 int i
, chips
, writeops
, chipsel
, res
;
902 struct nand_chip
*this = mtd
->priv
;
903 struct nand_bbt_descr
*td
= this->bbt_td
;
904 struct nand_bbt_descr
*md
= this->bbt_md
;
905 struct nand_bbt_descr
*rd
, *rd2
;
907 /* Do we have a bbt per chip ? */
908 if (td
->options
& NAND_BBT_PERCHIP
)
909 chips
= this->numchips
;
913 for (i
= 0; i
< chips
; i
++) {
917 /* Per chip or per device ? */
918 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
919 /* Mirrored table available ? */
921 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
926 if (td
->pages
[i
] == -1) {
928 td
->version
[i
] = md
->version
[i
];
933 if (md
->pages
[i
] == -1) {
935 md
->version
[i
] = td
->version
[i
];
940 if (td
->version
[i
] == md
->version
[i
]) {
942 if (!(td
->options
& NAND_BBT_VERSION
))
947 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
949 md
->version
[i
] = td
->version
[i
];
953 td
->version
[i
] = md
->version
[i
];
960 if (td
->pages
[i
] == -1) {
968 /* Create the bad block table by scanning the device ? */
969 if (!(td
->options
& NAND_BBT_CREATE
))
972 /* Create the table in memory by scanning the chip(s) */
973 if (!(this->options
& NAND_CREATE_EMPTY_BBT
))
974 create_bbt(mtd
, buf
, bd
, chipsel
);
980 /* read back first ? */
982 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
983 /* If they weren't versioned, read both. */
985 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
987 /* Write the bad block table to the device ? */
988 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
989 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
994 /* Write the mirror bad block table to the device ? */
995 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
996 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1005 * mark_bbt_regions - [GENERIC] mark the bad block table regions
1006 * @mtd: MTD device structure
1007 * @td: bad block table descriptor
1009 * The bad block table regions are marked as "bad" to prevent
1010 * accidental erasures / writes. The regions are identified by
1013 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
1015 struct nand_chip
*this = mtd
->priv
;
1016 int i
, j
, chips
, block
, nrblocks
, update
;
1017 uint8_t oldval
, newval
;
1019 /* Do we have a bbt per chip ? */
1020 if (td
->options
& NAND_BBT_PERCHIP
) {
1021 chips
= this->numchips
;
1022 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
1025 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
1028 for (i
= 0; i
< chips
; i
++) {
1029 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
1030 !(td
->options
& NAND_BBT_WRITE
)) {
1031 if (td
->pages
[i
] == -1)
1033 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
1035 oldval
= this->bbt
[(block
>> 3)];
1036 newval
= oldval
| (0x2 << (block
& 0x06));
1037 this->bbt
[(block
>> 3)] = newval
;
1038 if ((oldval
!= newval
) && td
->reserved_block_code
)
1039 nand_update_bbt(mtd
, (loff_t
)block
<< (this->bbt_erase_shift
- 1));
1043 if (td
->options
& NAND_BBT_LASTBLOCK
)
1044 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
1046 block
= i
* nrblocks
;
1048 for (j
= 0; j
< td
->maxblocks
; j
++) {
1049 oldval
= this->bbt
[(block
>> 3)];
1050 newval
= oldval
| (0x2 << (block
& 0x06));
1051 this->bbt
[(block
>> 3)] = newval
;
1052 if (oldval
!= newval
)
1056 /* If we want reserved blocks to be recorded to flash, and some
1057 new ones have been marked, then we need to update the stored
1058 bbts. This should only happen once. */
1059 if (update
&& td
->reserved_block_code
)
1060 nand_update_bbt(mtd
, (loff_t
)(block
- 2) << (this->bbt_erase_shift
- 1));
1065 * verify_bbt_descr - verify the bad block description
1066 * @mtd: MTD device structure
1067 * @bd: the table to verify
1069 * This functions performs a few sanity checks on the bad block description
1072 static void verify_bbt_descr(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1074 struct nand_chip
*this = mtd
->priv
;
1082 pattern_len
= bd
->len
;
1083 bits
= bd
->options
& NAND_BBT_NRBITS_MSK
;
1085 BUG_ON((this->bbt_options
& NAND_BBT_NO_OOB
) &&
1086 !(this->bbt_options
& NAND_BBT_USE_FLASH
));
1089 if (bd
->options
& NAND_BBT_VERSION
)
1092 if (bd
->options
& NAND_BBT_NO_OOB
) {
1093 BUG_ON(!(this->bbt_options
& NAND_BBT_USE_FLASH
));
1094 BUG_ON(!(this->bbt_options
& NAND_BBT_NO_OOB
));
1096 if (bd
->options
& NAND_BBT_VERSION
)
1097 BUG_ON(bd
->veroffs
!= bd
->len
);
1098 BUG_ON(bd
->options
& NAND_BBT_SAVECONTENT
);
1101 if (bd
->options
& NAND_BBT_PERCHIP
)
1102 table_size
= this->chipsize
>> this->bbt_erase_shift
;
1104 table_size
= mtd
->size
>> this->bbt_erase_shift
;
1107 if (bd
->options
& NAND_BBT_NO_OOB
)
1108 table_size
+= pattern_len
;
1109 BUG_ON(table_size
> (1 << this->bbt_erase_shift
));
1113 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1114 * @mtd: MTD device structure
1115 * @bd: descriptor for the good/bad block search pattern
1117 * The function checks, if a bad block table(s) is/are already
1118 * available. If not it scans the device for manufacturer
1119 * marked good / bad blocks and writes the bad block table(s) to
1120 * the selected place.
1122 * The bad block table memory is allocated here. It must be freed
1123 * by calling the nand_free_bbt function.
1126 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1128 struct nand_chip
*this = mtd
->priv
;
1131 struct nand_bbt_descr
*td
= this->bbt_td
;
1132 struct nand_bbt_descr
*md
= this->bbt_md
;
1134 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1135 /* Allocate memory (2bit per block) and clear the memory bad block table */
1136 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1138 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
1142 /* If no primary table decriptor is given, scan the device
1143 * to build a memory based bad block table
1146 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1147 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1153 verify_bbt_descr(mtd
, td
);
1154 verify_bbt_descr(mtd
, md
);
1156 /* Allocate a temporary buffer for one eraseblock incl. oob */
1157 len
= (1 << this->bbt_erase_shift
);
1158 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1161 printk(KERN_ERR
"nand_bbt: Out of memory\n");
1167 /* Is the bbt at a given page ? */
1168 if (td
->options
& NAND_BBT_ABSPAGE
) {
1169 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1171 /* Search the bad block table using a pattern in oob */
1172 res
= search_read_bbts(mtd
, buf
, td
, md
);
1176 res
= check_create(mtd
, buf
, bd
);
1178 /* Prevent the bbt regions from erasing / writing */
1179 mark_bbt_region(mtd
, td
);
1181 mark_bbt_region(mtd
, md
);
1188 * nand_update_bbt - [NAND Interface] update bad block table(s)
1189 * @mtd: MTD device structure
1190 * @offs: the offset of the newly marked block
1192 * The function updates the bad block table(s)
1194 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1196 struct nand_chip
*this = mtd
->priv
;
1197 int len
, res
= 0, writeops
= 0;
1200 struct nand_bbt_descr
*td
= this->bbt_td
;
1201 struct nand_bbt_descr
*md
= this->bbt_md
;
1203 if (!this->bbt
|| !td
)
1206 /* Allocate a temporary buffer for one eraseblock incl. oob */
1207 len
= (1 << this->bbt_erase_shift
);
1208 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1209 buf
= kmalloc(len
, GFP_KERNEL
);
1211 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1215 writeops
= md
!= NULL
? 0x03 : 0x01;
1217 /* Do we have a bbt per chip ? */
1218 if (td
->options
& NAND_BBT_PERCHIP
) {
1219 chip
= (int)(offs
>> this->chip_shift
);
1226 td
->version
[chip
]++;
1228 md
->version
[chip
]++;
1230 /* Write the bad block table to the device ? */
1231 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1232 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1236 /* Write the mirror bad block table to the device ? */
1237 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1238 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1246 /* Define some generic bad / good block scan pattern which are used
1247 * while scanning a device for factory marked good / bad blocks. */
1248 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1250 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1252 static struct nand_bbt_descr agand_flashbased
= {
1253 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1256 .pattern
= scan_agand_pattern
1259 /* Generic flash bbt decriptors
1261 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1262 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1264 static struct nand_bbt_descr bbt_main_descr
= {
1265 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1266 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1271 .pattern
= bbt_pattern
1274 static struct nand_bbt_descr bbt_mirror_descr
= {
1275 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1276 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1281 .pattern
= mirror_pattern
1284 static struct nand_bbt_descr bbt_main_no_bbt_descr
= {
1285 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1286 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1291 .pattern
= bbt_pattern
1294 static struct nand_bbt_descr bbt_mirror_no_bbt_descr
= {
1295 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1296 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1301 .pattern
= mirror_pattern
1305 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1306 * @this: NAND chip to create descriptor for
1308 * This function allocates and initializes a nand_bbt_descr for BBM detection
1309 * based on the properties of "this". The new descriptor is stored in
1310 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1311 * passed to this function.
1314 static int nand_create_default_bbt_descr(struct nand_chip
*this)
1316 struct nand_bbt_descr
*bd
;
1317 if (this->badblock_pattern
) {
1318 printk(KERN_WARNING
"BBT descr already allocated; not replacing.\n");
1321 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1323 printk(KERN_ERR
"nand_create_default_bbt_descr: Out of memory\n");
1326 bd
->options
= this->bbt_options
;
1327 bd
->offs
= this->badblockpos
;
1328 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1329 bd
->pattern
= scan_ff_pattern
;
1330 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1331 this->badblock_pattern
= bd
;
1336 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1337 * @mtd: MTD device structure
1339 * This function selects the default bad block table
1340 * support for the device and calls the nand_scan_bbt function
1343 int nand_default_bbt(struct mtd_info
*mtd
)
1345 struct nand_chip
*this = mtd
->priv
;
1347 /* Default for AG-AND. We must use a flash based
1348 * bad block table as the devices have factory marked
1349 * _good_ blocks. Erasing those blocks leads to loss
1350 * of the good / bad information, so we _must_ store
1351 * this information in a good / bad table during
1354 if (this->options
& NAND_IS_AND
) {
1355 /* Use the default pattern descriptors */
1356 if (!this->bbt_td
) {
1357 this->bbt_td
= &bbt_main_descr
;
1358 this->bbt_md
= &bbt_mirror_descr
;
1360 this->bbt_options
|= NAND_BBT_USE_FLASH
;
1361 return nand_scan_bbt(mtd
, &agand_flashbased
);
1364 /* Is a flash based bad block table requested ? */
1365 if (this->bbt_options
& NAND_BBT_USE_FLASH
) {
1366 /* Use the default pattern descriptors */
1367 if (!this->bbt_td
) {
1368 if (this->bbt_options
& NAND_BBT_NO_OOB
) {
1369 this->bbt_td
= &bbt_main_no_bbt_descr
;
1370 this->bbt_md
= &bbt_mirror_no_bbt_descr
;
1372 this->bbt_td
= &bbt_main_descr
;
1373 this->bbt_md
= &bbt_mirror_descr
;
1377 this->bbt_td
= NULL
;
1378 this->bbt_md
= NULL
;
1381 if (!this->badblock_pattern
)
1382 nand_create_default_bbt_descr(this);
1384 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1388 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1389 * @mtd: MTD device structure
1390 * @offs: offset in the device
1391 * @allowbbt: allow access to bad block table region
1394 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1396 struct nand_chip
*this = mtd
->priv
;
1400 /* Get block number * 2 */
1401 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1402 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1404 DEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1405 (unsigned int)offs
, block
>> 1, res
);
1413 return allowbbt
? 0 : 1;
1418 EXPORT_SYMBOL(nand_scan_bbt
);
1419 EXPORT_SYMBOL(nand_default_bbt
);