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_USE_FLASH_BBT) 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27 * If one of the BBTs is out of date or does not exist it is (re)created.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_USE_FLASH_BBT_NO_OOB should be used: it moves the ident pattern
40 * and the version byte into the data area and the OOB area will remain
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
64 #include <linux/mtd/compat.h>
65 #include <linux/mtd/mtd.h>
66 #include <linux/mtd/nand.h>
67 #include <linux/mtd/nand_ecc.h>
68 #include <linux/bitops.h>
70 #include <asm/errno.h>
72 static int check_pattern_no_oob(uint8_t *buf
, struct nand_bbt_descr
*td
)
76 ret
= memcmp(buf
, td
->pattern
, td
->len
);
83 * check_pattern - [GENERIC] check if a pattern is in the buffer
84 * @buf: the buffer to search
85 * @len: the length of buffer to search
86 * @paglen: the pagelength
87 * @td: search pattern descriptor
89 * Check for a pattern at the given place. Used to search bad block
90 * tables and good / bad block identifiers.
91 * If the SCAN_EMPTY option is set then check, if all bytes except the
92 * pattern area contain 0xff
95 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
100 if (td
->options
& NAND_BBT_NO_OOB
)
101 return check_pattern_no_oob(buf
, td
);
103 end
= paglen
+ td
->offs
;
104 if (td
->options
& NAND_BBT_SCANEMPTY
) {
105 for (i
= 0; i
< end
; i
++) {
112 /* Compare the pattern */
113 for (i
= 0; i
< td
->len
; i
++) {
114 if (p
[i
] != td
->pattern
[i
])
118 /* Check both positions 1 and 6 for pattern? */
119 if (td
->options
& NAND_BBT_SCANBYTE1AND6
) {
120 if (td
->options
& NAND_BBT_SCANEMPTY
) {
122 end
+= NAND_SMALL_BADBLOCK_POS
- td
->offs
;
123 /* Check region between positions 1 and 6 */
124 for (i
= 0; i
< NAND_SMALL_BADBLOCK_POS
- td
->offs
- td
->len
;
131 p
+= NAND_SMALL_BADBLOCK_POS
- td
->offs
;
133 /* Compare the pattern */
134 for (i
= 0; i
< td
->len
; i
++) {
135 if (p
[i
] != td
->pattern
[i
])
140 if (td
->options
& NAND_BBT_SCANEMPTY
) {
143 for (i
= end
; i
< len
; i
++) {
152 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
153 * @buf: the buffer to search
154 * @td: search pattern descriptor
156 * Check for a pattern at the given place. Used to search bad block
157 * tables and good / bad block identifiers. Same as check_pattern, but
158 * no optional empty check
161 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
166 /* Compare the pattern */
167 for (i
= 0; i
< td
->len
; i
++) {
168 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
171 /* Need to check location 1 AND 6? */
172 if (td
->options
& NAND_BBT_SCANBYTE1AND6
) {
173 for (i
= 0; i
< td
->len
; i
++) {
174 if (p
[NAND_SMALL_BADBLOCK_POS
+ i
] != td
->pattern
[i
])
182 * add_marker_len - compute the length of the marker in data area
183 * @td: BBT descriptor used for computation
185 * The length will be 0 if the markeris located in OOB area.
187 static u32
add_marker_len(struct nand_bbt_descr
*td
)
191 if (!(td
->options
& NAND_BBT_NO_OOB
))
195 if (td
->options
& NAND_BBT_VERSION
)
201 * read_bbt - [GENERIC] Read the bad block table starting from page
202 * @mtd: MTD device structure
203 * @buf: temporary buffer
204 * @page: the starting page
205 * @num: the number of bbt descriptors to read
206 * @td: the bbt describtion table
207 * @offs: offset in the memory table
209 * Read the bad block table starting from page.
212 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
213 struct nand_bbt_descr
*td
, int offs
)
215 int res
, i
, j
, act
= 0;
216 struct nand_chip
*this = mtd
->priv
;
217 size_t retlen
, len
, totlen
;
219 int bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
220 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
222 int reserved_block_code
= td
->reserved_block_code
;
224 totlen
= (num
* bits
) >> 3;
225 marker_len
= add_marker_len(td
);
226 from
= ((loff_t
) page
) << this->page_shift
;
229 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
232 * In case the BBT marker is not in the OOB area it
233 * will be just in the first page.
239 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
242 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
245 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
249 for (i
= 0; i
< len
; i
++) {
250 uint8_t dat
= buf
[i
];
251 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
252 uint8_t tmp
= (dat
>> j
) & msk
;
255 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
256 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%012llx\n",
257 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
258 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
259 mtd
->ecc_stats
.bbtblocks
++;
262 /* Leave it for now, if its matured we can move this
263 * message to MTD_DEBUG_LEVEL0 */
264 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%012llx\n",
265 (loff_t
)((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
266 /* Factory marked bad or worn out ? */
268 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
270 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
271 mtd
->ecc_stats
.badblocks
++;
281 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
282 * @mtd: MTD device structure
283 * @buf: temporary buffer
284 * @td: descriptor for the bad block table
285 * @chip: read the table for a specific chip, -1 read all chips.
286 * Applies only if NAND_BBT_PERCHIP option is set
288 * Read the bad block table for all chips starting at a given page
289 * We assume that the bbt bits are in consecutive order.
291 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
293 struct nand_chip
*this = mtd
->priv
;
296 if (td
->options
& NAND_BBT_PERCHIP
) {
298 for (i
= 0; i
< this->numchips
; i
++) {
299 if (chip
== -1 || chip
== i
)
300 res
= read_bbt(mtd
, buf
, td
->pages
[i
],
301 this->chipsize
>> this->bbt_erase_shift
,
305 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
308 res
= read_bbt(mtd
, buf
, td
->pages
[0],
309 mtd
->size
>> this->bbt_erase_shift
, td
, 0);
317 * BBT marker is in the first page, no OOB.
319 static int scan_read_raw_data(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
320 struct nand_bbt_descr
*td
)
326 if (td
->options
& NAND_BBT_VERSION
)
329 return mtd
->read(mtd
, offs
, len
, &retlen
, buf
);
333 * Scan read raw data from flash
335 static int scan_read_raw_oob(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
338 struct mtd_oob_ops ops
;
341 ops
.mode
= MTD_OOB_RAW
;
343 ops
.ooblen
= mtd
->oobsize
;
347 if (len
<= mtd
->writesize
) {
348 ops
.oobbuf
= buf
+ len
;
351 return mtd
->read_oob(mtd
, offs
, &ops
);
353 ops
.oobbuf
= buf
+ mtd
->writesize
;
355 ops
.len
= mtd
->writesize
;
356 res
= mtd
->read_oob(mtd
, offs
, &ops
);
362 buf
+= mtd
->oobsize
+ mtd
->writesize
;
363 len
-= mtd
->writesize
;
368 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
369 size_t len
, struct nand_bbt_descr
*td
)
371 if (td
->options
& NAND_BBT_NO_OOB
)
372 return scan_read_raw_data(mtd
, buf
, offs
, td
);
374 return scan_read_raw_oob(mtd
, buf
, offs
, len
);
378 * Scan write data with oob to flash
380 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
381 uint8_t *buf
, uint8_t *oob
)
383 struct mtd_oob_ops ops
;
385 ops
.mode
= MTD_OOB_PLACE
;
387 ops
.ooblen
= mtd
->oobsize
;
392 return mtd
->write_oob(mtd
, offs
, &ops
);
395 static u32
bbt_get_ver_offs(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
397 u32 ver_offs
= td
->veroffs
;
399 if (!(td
->options
& NAND_BBT_NO_OOB
))
400 ver_offs
+= mtd
->writesize
;
405 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
406 * @mtd: MTD device structure
407 * @buf: temporary buffer
408 * @td: descriptor for the bad block table
409 * @md: descriptor for the bad block table mirror
411 * Read the bad block table(s) for all chips starting at a given page
412 * We assume that the bbt bits are in consecutive order.
415 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
416 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
418 struct nand_chip
*this = mtd
->priv
;
420 /* Read the primary version, if available */
421 if (td
->options
& NAND_BBT_VERSION
) {
422 scan_read_raw(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
424 td
->version
[0] = buf
[bbt_get_ver_offs(mtd
, td
)];
425 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
426 td
->pages
[0], td
->version
[0]);
429 /* Read the mirror version, if available */
430 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
431 scan_read_raw(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
433 md
->version
[0] = buf
[bbt_get_ver_offs(mtd
, md
)];
434 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
435 md
->pages
[0], md
->version
[0]);
441 * Scan a given block full
443 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
444 loff_t offs
, uint8_t *buf
, size_t readlen
,
445 int scanlen
, int len
)
449 ret
= scan_read_raw_oob(mtd
, buf
, offs
, readlen
);
453 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
454 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
461 * Scan a given block partially
463 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
464 loff_t offs
, uint8_t *buf
, int len
)
466 struct mtd_oob_ops ops
;
469 ops
.ooblen
= mtd
->oobsize
;
473 ops
.mode
= MTD_OOB_PLACE
;
475 for (j
= 0; j
< len
; j
++) {
477 * Read the full oob until read_oob is fixed to
478 * handle single byte reads for 16 bit
481 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
485 if (check_short_pattern(buf
, bd
))
488 offs
+= mtd
->writesize
;
494 * create_bbt - [GENERIC] Create a bad block table by scanning the device
495 * @mtd: MTD device structure
496 * @buf: temporary buffer
497 * @bd: descriptor for the good/bad block search pattern
498 * @chip: create the table for a specific chip, -1 read all chips.
499 * Applies only if NAND_BBT_PERCHIP option is set
501 * Create a bad block table by scanning the device
502 * for the given good/bad block identify pattern
504 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
505 struct nand_bbt_descr
*bd
, int chip
)
507 struct nand_chip
*this = mtd
->priv
;
508 int i
, numblocks
, len
, scanlen
;
513 MTDDEBUG(MTD_DEBUG_LEVEL0
, "Scanning device for bad blocks\n");
515 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
516 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
517 else if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
522 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
523 /* We need only read few bytes from the OOB area */
527 /* Full page content should be read */
528 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
529 readlen
= len
* mtd
->writesize
;
533 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
534 * below as it makes shifting and masking less painful */
535 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
539 if (chip
>= this->numchips
) {
540 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
541 chip
+ 1, this->numchips
);
544 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
545 startblock
= chip
* numblocks
;
546 numblocks
+= startblock
;
547 from
= (loff_t
)startblock
<< (this->bbt_erase_shift
- 1);
550 if (this->options
& NAND_BBT_SCANLASTPAGE
)
551 from
+= mtd
->erasesize
- (mtd
->writesize
* len
);
553 for (i
= startblock
; i
< numblocks
;) {
556 BUG_ON(bd
->options
& NAND_BBT_NO_OOB
);
558 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
559 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
562 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
568 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
569 MTDDEBUG(MTD_DEBUG_LEVEL0
,
570 "Bad eraseblock %d at 0x%012llx\n",
571 i
>> 1, (unsigned long long)from
);
572 mtd
->ecc_stats
.badblocks
++;
576 from
+= (1 << this->bbt_erase_shift
);
582 * search_bbt - [GENERIC] scan the device for a specific bad block table
583 * @mtd: MTD device structure
584 * @buf: temporary buffer
585 * @td: descriptor for the bad block table
587 * Read the bad block table by searching for a given ident pattern.
588 * Search is preformed either from the beginning up or from the end of
589 * the device downwards. The search starts always at the start of a
591 * If the option NAND_BBT_PERCHIP is given, each chip is searched
592 * for a bbt, which contains the bad block information of this chip.
593 * This is necessary to provide support for certain DOC devices.
595 * The bbt ident pattern resides in the oob area of the first page
598 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
600 struct nand_chip
*this = mtd
->priv
;
602 int startblock
, block
, dir
;
603 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
605 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
607 /* Search direction top -> down ? */
608 if (td
->options
& NAND_BBT_LASTBLOCK
) {
609 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
616 /* Do we have a bbt per chip ? */
617 if (td
->options
& NAND_BBT_PERCHIP
) {
618 chips
= this->numchips
;
619 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
620 startblock
&= bbtblocks
- 1;
623 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
626 for (i
= 0; i
< chips
; i
++) {
627 /* Reset version information */
630 /* Scan the maximum number of blocks */
631 for (block
= 0; block
< td
->maxblocks
; block
++) {
633 int actblock
= startblock
+ dir
* block
;
634 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
636 /* Read first page */
637 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
, td
);
638 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
639 td
->pages
[i
] = actblock
<< blocktopage
;
640 if (td
->options
& NAND_BBT_VERSION
) {
641 offs
= bbt_get_ver_offs(mtd
, td
);
642 td
->version
[i
] = buf
[offs
];
647 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
649 /* Check, if we found a bbt for each requested chip */
650 for (i
= 0; i
< chips
; i
++) {
651 if (td
->pages
[i
] == -1)
652 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
654 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
661 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
662 * @mtd: MTD device structure
663 * @buf: temporary buffer
664 * @td: descriptor for the bad block table
665 * @md: descriptor for the bad block table mirror
667 * Search and read the bad block table(s)
669 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
671 /* Search the primary table */
672 search_bbt(mtd
, buf
, td
);
674 /* Search the mirror table */
676 search_bbt(mtd
, buf
, md
);
678 /* Force result check */
683 * write_bbt - [GENERIC] (Re)write the bad block table
685 * @mtd: MTD device structure
686 * @buf: temporary buffer
687 * @td: descriptor for the bad block table
688 * @md: descriptor for the bad block table mirror
689 * @chipsel: selector for a specific chip, -1 for all
691 * (Re)write the bad block table
694 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
695 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
698 struct nand_chip
*this = mtd
->priv
;
699 struct erase_info einfo
;
700 int i
, j
, res
, chip
= 0;
701 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
702 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
704 uint8_t rcode
= td
->reserved_block_code
;
705 size_t retlen
, len
= 0;
707 struct mtd_oob_ops ops
;
709 ops
.ooblen
= mtd
->oobsize
;
712 ops
.mode
= MTD_OOB_PLACE
;
716 /* Write bad block table per chip rather than per device ? */
717 if (td
->options
& NAND_BBT_PERCHIP
) {
718 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
719 /* Full device write or specific chip ? */
721 nrchips
= this->numchips
;
723 nrchips
= chipsel
+ 1;
727 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
731 /* Loop through the chips */
732 for (; chip
< nrchips
; chip
++) {
734 /* There was already a version of the table, reuse the page
735 * This applies for absolute placement too, as we have the
736 * page nr. in td->pages.
738 if (td
->pages
[chip
] != -1) {
739 page
= td
->pages
[chip
];
743 /* Automatic placement of the bad block table */
744 /* Search direction top -> down ? */
745 if (td
->options
& NAND_BBT_LASTBLOCK
) {
746 startblock
= numblocks
* (chip
+ 1) - 1;
749 startblock
= chip
* numblocks
;
753 for (i
= 0; i
< td
->maxblocks
; i
++) {
754 int block
= startblock
+ dir
* i
;
755 /* Check, if the block is bad */
756 switch ((this->bbt
[block
>> 2] >>
757 (2 * (block
& 0x03))) & 0x03) {
763 (this->bbt_erase_shift
- this->page_shift
);
764 /* Check, if the block is used by the mirror table */
765 if (!md
|| md
->pages
[chip
] != page
)
768 printk(KERN_ERR
"No space left to write bad block table\n");
772 /* Set up shift count and masks for the flash table */
773 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
776 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
779 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
782 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
785 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
788 default: return -EINVAL
;
791 bbtoffs
= chip
* (numblocks
>> 2);
793 to
= ((loff_t
) page
) << this->page_shift
;
795 /* Must we save the block contents ? */
796 if (td
->options
& NAND_BBT_SAVECONTENT
) {
797 /* Make it block aligned */
798 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
799 len
= 1 << this->bbt_erase_shift
;
800 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
803 printk(KERN_INFO
"nand_bbt: Error "
804 "reading block for writing "
805 "the bad block table\n");
808 printk(KERN_WARNING
"nand_bbt: ECC error "
809 "while reading block for writing "
810 "bad block table\n");
813 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
814 ops
.oobbuf
= &buf
[len
];
815 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
816 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
819 /* Calc the byte offset in the buffer */
820 pageoffs
= page
- (int)(to
>> this->page_shift
);
821 offs
= pageoffs
<< this->page_shift
;
822 /* Preset the bbt area with 0xff */
823 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
824 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
826 } else if (td
->options
& NAND_BBT_NO_OOB
) {
829 /* the version byte */
830 if (td
->options
& NAND_BBT_VERSION
)
833 len
= (size_t) (numblocks
>> sft
);
835 /* Make it page aligned ! */
836 len
= ALIGN(len
, mtd
->writesize
);
837 /* Preset the buffer with 0xff */
838 memset(buf
, 0xff, len
);
839 /* Pattern is located at the begin of first page */
840 memcpy(buf
, td
->pattern
, td
->len
);
843 len
= (size_t) (numblocks
>> sft
);
844 /* Make it page aligned ! */
845 len
= ALIGN(len
, mtd
->writesize
);
846 /* Preset the buffer with 0xff */
847 memset(buf
, 0xff, len
+
848 (len
>> this->page_shift
)* mtd
->oobsize
);
851 /* Pattern is located in oob area of first page */
852 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
855 if (td
->options
& NAND_BBT_VERSION
)
856 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
858 /* walk through the memory table */
859 for (i
= 0; i
< numblocks
;) {
861 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
862 for (j
= 0; j
< 4; j
++, i
++) {
863 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
864 /* Do not store the reserved bbt blocks ! */
865 buf
[offs
+ (i
>> sft
)] &=
866 ~(msk
[dat
& 0x03] << sftcnt
);
871 memset(&einfo
, 0, sizeof(einfo
));
874 einfo
.len
= 1 << this->bbt_erase_shift
;
875 res
= nand_erase_nand(mtd
, &einfo
, 1);
879 res
= scan_write_bbt(mtd
, to
, len
, buf
,
880 td
->options
& NAND_BBT_NO_OOB
? NULL
:
885 printk(KERN_DEBUG
"Bad block table written to 0x%012llx, version "
886 "0x%02X\n", (unsigned long long)to
, td
->version
[chip
]);
888 /* Mark it as used */
889 td
->pages
[chip
] = page
;
895 "nand_bbt: Error while writing bad block table %d\n", res
);
900 * nand_memory_bbt - [GENERIC] create a memory based bad block table
901 * @mtd: MTD device structure
902 * @bd: descriptor for the good/bad block search pattern
904 * The function creates a memory based bbt by scanning the device
905 * for manufacturer / software marked good / bad blocks
907 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
909 struct nand_chip
*this = mtd
->priv
;
911 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
912 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
916 * check_create - [GENERIC] create and write bbt(s) if necessary
917 * @mtd: MTD device structure
918 * @buf: temporary buffer
919 * @bd: descriptor for the good/bad block search pattern
921 * The function checks the results of the previous call to read_bbt
922 * and creates / updates the bbt(s) if necessary
923 * Creation is necessary if no bbt was found for the chip/device
924 * Update is necessary if one of the tables is missing or the
925 * version nr. of one table is less than the other
927 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
929 int i
, chips
, writeops
, chipsel
, res
;
930 struct nand_chip
*this = mtd
->priv
;
931 struct nand_bbt_descr
*td
= this->bbt_td
;
932 struct nand_bbt_descr
*md
= this->bbt_md
;
933 struct nand_bbt_descr
*rd
, *rd2
;
935 /* Do we have a bbt per chip ? */
936 if (td
->options
& NAND_BBT_PERCHIP
)
937 chips
= this->numchips
;
941 for (i
= 0; i
< chips
; i
++) {
945 /* Per chip or per device ? */
946 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
947 /* Mirrored table available ? */
949 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
954 if (td
->pages
[i
] == -1) {
956 td
->version
[i
] = md
->version
[i
];
961 if (md
->pages
[i
] == -1) {
963 md
->version
[i
] = td
->version
[i
];
968 if (td
->version
[i
] == md
->version
[i
]) {
970 if (!(td
->options
& NAND_BBT_VERSION
))
975 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
977 md
->version
[i
] = td
->version
[i
];
981 td
->version
[i
] = md
->version
[i
];
988 if (td
->pages
[i
] == -1) {
996 /* Create the bad block table by scanning the device ? */
997 if (!(td
->options
& NAND_BBT_CREATE
))
1000 /* Create the table in memory by scanning the chip(s) */
1001 if (!(this->options
& NAND_CREATE_EMPTY_BBT
))
1002 create_bbt(mtd
, buf
, bd
, chipsel
);
1008 /* read back first ? */
1010 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
1011 /* If they weren't versioned, read both. */
1013 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
1015 /* Write the bad block table to the device ? */
1016 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1017 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1022 /* Write the mirror bad block table to the device ? */
1023 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1024 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1033 * mark_bbt_regions - [GENERIC] mark the bad block table regions
1034 * @mtd: MTD device structure
1035 * @td: bad block table descriptor
1037 * The bad block table regions are marked as "bad" to prevent
1038 * accidental erasures / writes. The regions are identified by
1041 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
1043 struct nand_chip
*this = mtd
->priv
;
1044 int i
, j
, chips
, block
, nrblocks
, update
;
1045 uint8_t oldval
, newval
;
1047 /* Do we have a bbt per chip ? */
1048 if (td
->options
& NAND_BBT_PERCHIP
) {
1049 chips
= this->numchips
;
1050 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
1053 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
1056 for (i
= 0; i
< chips
; i
++) {
1057 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
1058 !(td
->options
& NAND_BBT_WRITE
)) {
1059 if (td
->pages
[i
] == -1)
1061 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
1063 oldval
= this->bbt
[(block
>> 3)];
1064 newval
= oldval
| (0x2 << (block
& 0x06));
1065 this->bbt
[(block
>> 3)] = newval
;
1066 if ((oldval
!= newval
) && td
->reserved_block_code
)
1067 nand_update_bbt(mtd
, (loff_t
)block
<< (this->bbt_erase_shift
- 1));
1071 if (td
->options
& NAND_BBT_LASTBLOCK
)
1072 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
1074 block
= i
* nrblocks
;
1076 for (j
= 0; j
< td
->maxblocks
; j
++) {
1077 oldval
= this->bbt
[(block
>> 3)];
1078 newval
= oldval
| (0x2 << (block
& 0x06));
1079 this->bbt
[(block
>> 3)] = newval
;
1080 if (oldval
!= newval
)
1084 /* If we want reserved blocks to be recorded to flash, and some
1085 new ones have been marked, then we need to update the stored
1086 bbts. This should only happen once. */
1087 if (update
&& td
->reserved_block_code
)
1088 nand_update_bbt(mtd
, (loff_t
)(block
- 2) << (this->bbt_erase_shift
- 1));
1093 * verify_bbt_descr - verify the bad block description
1094 * @mtd: MTD device structure
1095 * @bd: the table to verify
1097 * This functions performs a few sanity checks on the bad block description
1100 static void verify_bbt_descr(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1102 struct nand_chip
*this = mtd
->priv
;
1110 pattern_len
= bd
->len
;
1111 bits
= bd
->options
& NAND_BBT_NRBITS_MSK
;
1113 BUG_ON((this->options
& NAND_USE_FLASH_BBT_NO_OOB
) &&
1114 !(this->options
& NAND_USE_FLASH_BBT
));
1117 if (bd
->options
& NAND_BBT_VERSION
)
1120 if (bd
->options
& NAND_BBT_NO_OOB
) {
1121 BUG_ON(!(this->options
& NAND_USE_FLASH_BBT
));
1122 BUG_ON(!(this->options
& NAND_USE_FLASH_BBT_NO_OOB
));
1124 if (bd
->options
& NAND_BBT_VERSION
)
1125 BUG_ON(bd
->veroffs
!= bd
->len
);
1126 BUG_ON(bd
->options
& NAND_BBT_SAVECONTENT
);
1129 if (bd
->options
& NAND_BBT_PERCHIP
)
1130 table_size
= this->chipsize
>> this->bbt_erase_shift
;
1132 table_size
= mtd
->size
>> this->bbt_erase_shift
;
1135 if (bd
->options
& NAND_BBT_NO_OOB
)
1136 table_size
+= pattern_len
;
1137 BUG_ON(table_size
> (1 << this->bbt_erase_shift
));
1141 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1142 * @mtd: MTD device structure
1143 * @bd: descriptor for the good/bad block search pattern
1145 * The function checks, if a bad block table(s) is/are already
1146 * available. If not it scans the device for manufacturer
1147 * marked good / bad blocks and writes the bad block table(s) to
1148 * the selected place.
1150 * The bad block table memory is allocated here. It must be freed
1151 * by calling the nand_free_bbt function.
1154 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1156 struct nand_chip
*this = mtd
->priv
;
1159 struct nand_bbt_descr
*td
= this->bbt_td
;
1160 struct nand_bbt_descr
*md
= this->bbt_md
;
1162 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1163 /* Allocate memory (2bit per block) and clear the memory bad block table */
1164 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1166 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
1170 /* If no primary table decriptor is given, scan the device
1171 * to build a memory based bad block table
1174 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1175 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
1181 verify_bbt_descr(mtd
, td
);
1182 verify_bbt_descr(mtd
, md
);
1184 /* Allocate a temporary buffer for one eraseblock incl. oob */
1185 len
= (1 << this->bbt_erase_shift
);
1186 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1189 printk(KERN_ERR
"nand_bbt: Out of memory\n");
1195 /* Is the bbt at a given page ? */
1196 if (td
->options
& NAND_BBT_ABSPAGE
) {
1197 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1199 /* Search the bad block table using a pattern in oob */
1200 res
= search_read_bbts(mtd
, buf
, td
, md
);
1204 res
= check_create(mtd
, buf
, bd
);
1206 /* Prevent the bbt regions from erasing / writing */
1207 mark_bbt_region(mtd
, td
);
1209 mark_bbt_region(mtd
, md
);
1216 * nand_update_bbt - [NAND Interface] update bad block table(s)
1217 * @mtd: MTD device structure
1218 * @offs: the offset of the newly marked block
1220 * The function updates the bad block table(s)
1222 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1224 struct nand_chip
*this = mtd
->priv
;
1225 int len
, res
= 0, writeops
= 0;
1228 struct nand_bbt_descr
*td
= this->bbt_td
;
1229 struct nand_bbt_descr
*md
= this->bbt_md
;
1231 if (!this->bbt
|| !td
)
1234 /* Allocate a temporary buffer for one eraseblock incl. oob */
1235 len
= (1 << this->bbt_erase_shift
);
1236 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1237 buf
= kmalloc(len
, GFP_KERNEL
);
1239 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1243 writeops
= md
!= NULL
? 0x03 : 0x01;
1245 /* Do we have a bbt per chip ? */
1246 if (td
->options
& NAND_BBT_PERCHIP
) {
1247 chip
= (int)(offs
>> this->chip_shift
);
1254 td
->version
[chip
]++;
1256 md
->version
[chip
]++;
1258 /* Write the bad block table to the device ? */
1259 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1260 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1264 /* Write the mirror bad block table to the device ? */
1265 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1266 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1274 /* Define some generic bad / good block scan pattern which are used
1275 * while scanning a device for factory marked good / bad blocks. */
1276 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1278 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1280 static struct nand_bbt_descr agand_flashbased
= {
1281 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1284 .pattern
= scan_agand_pattern
1287 /* Generic flash bbt decriptors
1289 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1290 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1292 static struct nand_bbt_descr bbt_main_descr
= {
1293 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1294 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1299 .pattern
= bbt_pattern
1302 static struct nand_bbt_descr bbt_mirror_descr
= {
1303 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1304 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1309 .pattern
= mirror_pattern
1312 static struct nand_bbt_descr bbt_main_no_bbt_descr
= {
1313 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1314 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1319 .pattern
= bbt_pattern
1322 static struct nand_bbt_descr bbt_mirror_no_bbt_descr
= {
1323 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1324 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1329 .pattern
= mirror_pattern
1332 #define BBT_SCAN_OPTIONS (NAND_BBT_SCANLASTPAGE | NAND_BBT_SCAN2NDPAGE | \
1333 NAND_BBT_SCANBYTE1AND6)
1335 * nand_create_default_bbt_descr - [Internal] Creates a BBT descriptor structure
1336 * @this: NAND chip to create descriptor for
1338 * This function allocates and initializes a nand_bbt_descr for BBM detection
1339 * based on the properties of "this". The new descriptor is stored in
1340 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1341 * passed to this function.
1344 static int nand_create_default_bbt_descr(struct nand_chip
*this)
1346 struct nand_bbt_descr
*bd
;
1347 if (this->badblock_pattern
) {
1348 printk(KERN_WARNING
"BBT descr already allocated; not replacing.\n");
1351 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1353 printk(KERN_ERR
"nand_create_default_bbt_descr: Out of memory\n");
1356 bd
->options
= this->options
& BBT_SCAN_OPTIONS
;
1357 bd
->offs
= this->badblockpos
;
1358 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1359 bd
->pattern
= scan_ff_pattern
;
1360 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1361 this->badblock_pattern
= bd
;
1366 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1367 * @mtd: MTD device structure
1369 * This function selects the default bad block table
1370 * support for the device and calls the nand_scan_bbt function
1373 int nand_default_bbt(struct mtd_info
*mtd
)
1375 struct nand_chip
*this = mtd
->priv
;
1377 /* Default for AG-AND. We must use a flash based
1378 * bad block table as the devices have factory marked
1379 * _good_ blocks. Erasing those blocks leads to loss
1380 * of the good / bad information, so we _must_ store
1381 * this information in a good / bad table during
1384 if (this->options
& NAND_IS_AND
) {
1385 /* Use the default pattern descriptors */
1386 if (!this->bbt_td
) {
1387 this->bbt_td
= &bbt_main_descr
;
1388 this->bbt_md
= &bbt_mirror_descr
;
1390 this->options
|= NAND_USE_FLASH_BBT
;
1391 return nand_scan_bbt(mtd
, &agand_flashbased
);
1394 /* Is a flash based bad block table requested ? */
1395 if (this->options
& NAND_USE_FLASH_BBT
) {
1396 /* Use the default pattern descriptors */
1397 if (!this->bbt_td
) {
1398 if (this->options
& NAND_USE_FLASH_BBT_NO_OOB
) {
1399 this->bbt_td
= &bbt_main_no_bbt_descr
;
1400 this->bbt_md
= &bbt_mirror_no_bbt_descr
;
1402 this->bbt_td
= &bbt_main_descr
;
1403 this->bbt_md
= &bbt_mirror_descr
;
1407 this->bbt_td
= NULL
;
1408 this->bbt_md
= NULL
;
1411 if (!this->badblock_pattern
)
1412 nand_create_default_bbt_descr(this);
1414 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1418 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1419 * @mtd: MTD device structure
1420 * @offs: offset in the device
1421 * @allowbbt: allow access to bad block table region
1424 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1426 struct nand_chip
*this = mtd
->priv
;
1430 /* Get block number * 2 */
1431 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1432 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1434 MTDDEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1435 (unsigned int)offs
, block
>> 1, res
);
1443 return allowbbt
? 0 : 1;