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 * $Id: nand_bbt.c,v 1.36 2005/11/07 11:14:30 gleixner Exp $
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
17 * When nand_scan_bbt is called, then it tries to find the bad block table
18 * depending on the options in the bbt descriptor(s). If a bbt is found
19 * then the contents are read and the memory based bbt is created. If a
20 * mirrored bbt is selected then the mirror is searched too and the
21 * versions are compared. If the mirror has a greater version number
22 * than the mirror bbt is used to build the memory based bbt.
23 * If the tables are not versioned, then we "or" the bad block information.
24 * If one of the bbt's is out of date or does not exist it is (re)created.
25 * If no bbt exists at all then the device is scanned for factory marked
26 * good / bad blocks and the bad block tables are created.
28 * For manufacturer created bbts like the one found on M-SYS DOC devices
29 * the bbt is searched and read but never created
31 * The autogenerated bad block table is located in the last good blocks
32 * of the device. The table is mirrored, so it can be updated eventually.
33 * The table is marked in the oob area with an ident pattern and a version
34 * number which indicates which of both tables is more up to date.
36 * The table uses 2 bits per block
38 * 00b: block is factory marked bad
39 * 01b, 10b: block is marked bad due to wear
41 * The memory bad block table uses the following scheme:
43 * 01b: block is marked bad due to wear
44 * 10b: block is reserved (to protect the bbt area)
45 * 11b: block is factory marked bad
47 * Multichip devices like DOC store the bad block info per floor.
49 * Following assumptions are made:
50 * - bbts start at a page boundary, if autolocated on a block boundary
51 * - the space necessary for a bbt in FLASH does not exceed a block boundary
57 #include <linux/mtd/compat.h>
58 #include <linux/mtd/mtd.h>
59 #include <linux/mtd/nand.h>
61 #include <asm/errno.h>
65 #include <linux/slab.h>
66 #include <linux/types.h>
67 #include <linux/mtd/mtd.h>
68 #include <linux/mtd/nand.h>
69 #include <linux/mtd/nand_ecc.h>
70 #include <linux/mtd/compatmac.h>
71 #include <linux/bitops.h>
72 #include <linux/delay.h>
73 #include <linux/vmalloc.h>
77 * check_pattern - [GENERIC] check if a pattern is in the buffer
78 * @buf: the buffer to search
79 * @len: the length of buffer to search
80 * @paglen: the pagelength
81 * @td: search pattern descriptor
83 * Check for a pattern at the given place. Used to search bad block
84 * tables and good / bad block identifiers.
85 * If the SCAN_EMPTY option is set then check, if all bytes except the
86 * pattern area contain 0xff
89 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
94 end
= paglen
+ td
->offs
;
95 if (td
->options
& NAND_BBT_SCANEMPTY
) {
96 for (i
= 0; i
< end
; i
++) {
103 /* Compare the pattern */
104 for (i
= 0; i
< td
->len
; i
++) {
105 if (p
[i
] != td
->pattern
[i
])
109 if (td
->options
& NAND_BBT_SCANEMPTY
) {
112 for (i
= end
; i
< len
; i
++) {
121 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
122 * @buf: the buffer to search
123 * @td: search pattern descriptor
125 * Check for a pattern at the given place. Used to search bad block
126 * tables and good / bad block identifiers. Same as check_pattern, but
127 * no optional empty check
130 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
135 /* Compare the pattern */
136 for (i
= 0; i
< td
->len
; i
++) {
137 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
144 * read_bbt - [GENERIC] Read the bad block table starting from page
145 * @mtd: MTD device structure
146 * @buf: temporary buffer
147 * @page: the starting page
148 * @num: the number of bbt descriptors to read
149 * @bits: number of bits per block
150 * @offs: offset in the memory table
151 * @reserved_block_code: Pattern to identify reserved blocks
153 * Read the bad block table starting from page.
156 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
157 int bits
, int offs
, int reserved_block_code
)
159 int res
, i
, j
, act
= 0;
160 struct nand_chip
*this = mtd
->priv
;
161 size_t retlen
, len
, totlen
;
163 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
165 totlen
= (num
* bits
) >> 3;
166 from
= ((loff_t
) page
) << this->page_shift
;
169 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
170 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
173 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
176 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
180 for (i
= 0; i
< len
; i
++) {
181 uint8_t dat
= buf
[i
];
182 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
183 uint8_t tmp
= (dat
>> j
) & msk
;
186 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
187 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%08x\n",
188 ((offs
<< 2) + (act
>> 1)) << 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%08x\n",
196 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
197 /* Factory marked bad or worn out ? */
199 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
201 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
202 mtd
->ecc_stats
.badblocks
++;
212 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
213 * @mtd: MTD device structure
214 * @buf: temporary buffer
215 * @td: descriptor for the bad block table
216 * @chip: read the table for a specific chip, -1 read all chips.
217 * Applies only if NAND_BBT_PERCHIP option is set
219 * Read the bad block table for all chips starting at a given page
220 * We assume that the bbt bits are in consecutive order.
222 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
224 struct nand_chip
*this = mtd
->priv
;
228 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
229 if (td
->options
& NAND_BBT_PERCHIP
) {
231 for (i
= 0; i
< this->numchips
; i
++) {
232 if (chip
== -1 || chip
== i
)
233 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
236 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
239 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
247 * Scan read raw data from flash
249 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
252 struct mtd_oob_ops ops
;
254 ops
.mode
= MTD_OOB_RAW
;
256 ops
.ooblen
= mtd
->oobsize
;
261 return mtd
->read_oob(mtd
, offs
, &ops
);
265 * Scan write data with oob to flash
267 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
268 uint8_t *buf
, uint8_t *oob
)
270 struct mtd_oob_ops ops
;
272 ops
.mode
= MTD_OOB_PLACE
;
274 ops
.ooblen
= mtd
->oobsize
;
279 return mtd
->write_oob(mtd
, offs
, &ops
);
283 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
284 * @mtd: MTD device structure
285 * @buf: temporary buffer
286 * @td: descriptor for the bad block table
287 * @md: descriptor for the bad block table mirror
289 * Read the bad block table(s) for all chips starting at a given page
290 * We assume that the bbt bits are in consecutive order.
293 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
294 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
296 struct nand_chip
*this = mtd
->priv
;
298 /* Read the primary version, if available */
299 if (td
->options
& NAND_BBT_VERSION
) {
300 scan_read_raw(mtd
, buf
, td
->pages
[0] << this->page_shift
,
302 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
303 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
304 td
->pages
[0], td
->version
[0]);
307 /* Read the mirror version, if available */
308 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
309 scan_read_raw(mtd
, buf
, md
->pages
[0] << this->page_shift
,
311 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
312 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
313 md
->pages
[0], md
->version
[0]);
319 * Scan a given block full
321 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
322 loff_t offs
, uint8_t *buf
, size_t readlen
,
323 int scanlen
, int len
)
327 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
331 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
332 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
339 * Scan a given block partially
341 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
342 loff_t offs
, uint8_t *buf
, int len
)
344 struct mtd_oob_ops ops
;
347 ops
.ooblen
= mtd
->oobsize
;
351 ops
.mode
= MTD_OOB_PLACE
;
353 for (j
= 0; j
< len
; j
++) {
355 * Read the full oob until read_oob is fixed to
356 * handle single byte reads for 16 bit
359 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
363 if (check_short_pattern(buf
, bd
))
366 offs
+= mtd
->writesize
;
372 * create_bbt - [GENERIC] Create a bad block table by scanning the device
373 * @mtd: MTD device structure
374 * @buf: temporary buffer
375 * @bd: descriptor for the good/bad block search pattern
376 * @chip: create the table for a specific chip, -1 read all chips.
377 * Applies only if NAND_BBT_PERCHIP option is set
379 * Create a bad block table by scanning the device
380 * for the given good/bad block identify pattern
382 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
383 struct nand_bbt_descr
*bd
, int chip
)
385 struct nand_chip
*this = mtd
->priv
;
386 int i
, numblocks
, len
, scanlen
;
391 MTDDEBUG (MTD_DEBUG_LEVEL0
, "Scanning device for bad blocks\n");
393 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
394 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
396 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
402 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
403 /* We need only read few bytes from the OOB area */
407 /* Full page content should be read */
408 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
409 readlen
= len
* mtd
->writesize
;
413 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
414 * below as it makes shifting and masking less painful */
415 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
419 if (chip
>= this->numchips
) {
420 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
421 chip
+ 1, this->numchips
);
424 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
425 startblock
= chip
* numblocks
;
426 numblocks
+= startblock
;
427 from
= startblock
<< (this->bbt_erase_shift
- 1);
430 for (i
= startblock
; i
< numblocks
;) {
433 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
434 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
437 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
443 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
444 MTDDEBUG (MTD_DEBUG_LEVEL0
,
445 "Bad eraseblock %d at 0x%08x\n",
446 i
>> 1, (unsigned int)from
);
447 mtd
->ecc_stats
.badblocks
++;
451 from
+= (1 << this->bbt_erase_shift
);
457 * search_bbt - [GENERIC] scan the device for a specific bad block table
458 * @mtd: MTD device structure
459 * @buf: temporary buffer
460 * @td: descriptor for the bad block table
462 * Read the bad block table by searching for a given ident pattern.
463 * Search is preformed either from the beginning up or from the end of
464 * the device downwards. The search starts always at the start of a
466 * If the option NAND_BBT_PERCHIP is given, each chip is searched
467 * for a bbt, which contains the bad block information of this chip.
468 * This is necessary to provide support for certain DOC devices.
470 * The bbt ident pattern resides in the oob area of the first page
473 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
475 struct nand_chip
*this = mtd
->priv
;
477 int bits
, startblock
, block
, dir
;
478 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
480 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
482 /* Search direction top -> down ? */
483 if (td
->options
& NAND_BBT_LASTBLOCK
) {
484 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
491 /* Do we have a bbt per chip ? */
492 if (td
->options
& NAND_BBT_PERCHIP
) {
493 chips
= this->numchips
;
494 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
495 startblock
&= bbtblocks
- 1;
498 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
501 /* Number of bits for each erase block in the bbt */
502 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
504 for (i
= 0; i
< chips
; i
++) {
505 /* Reset version information */
508 /* Scan the maximum number of blocks */
509 for (block
= 0; block
< td
->maxblocks
; block
++) {
511 int actblock
= startblock
+ dir
* block
;
512 loff_t offs
= actblock
<< this->bbt_erase_shift
;
514 /* Read first page */
515 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
516 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
517 td
->pages
[i
] = actblock
<< blocktopage
;
518 if (td
->options
& NAND_BBT_VERSION
) {
519 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
524 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
526 /* Check, if we found a bbt for each requested chip */
527 for (i
= 0; i
< chips
; i
++) {
528 if (td
->pages
[i
] == -1)
529 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
531 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
538 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
539 * @mtd: MTD device structure
540 * @buf: temporary buffer
541 * @td: descriptor for the bad block table
542 * @md: descriptor for the bad block table mirror
544 * Search and read the bad block table(s)
546 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
548 /* Search the primary table */
549 search_bbt(mtd
, buf
, td
);
551 /* Search the mirror table */
553 search_bbt(mtd
, buf
, md
);
555 /* Force result check */
560 * write_bbt - [GENERIC] (Re)write the bad block table
562 * @mtd: MTD device structure
563 * @buf: temporary buffer
564 * @td: descriptor for the bad block table
565 * @md: descriptor for the bad block table mirror
566 * @chipsel: selector for a specific chip, -1 for all
568 * (Re)write the bad block table
571 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
572 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
575 struct nand_chip
*this = mtd
->priv
;
576 struct erase_info einfo
;
577 int i
, j
, res
, chip
= 0;
578 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
579 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
581 uint8_t rcode
= td
->reserved_block_code
;
582 size_t retlen
, len
= 0;
584 struct mtd_oob_ops ops
;
586 ops
.ooblen
= mtd
->oobsize
;
589 ops
.mode
= MTD_OOB_PLACE
;
593 /* Write bad block table per chip rather than per device ? */
594 if (td
->options
& NAND_BBT_PERCHIP
) {
595 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
596 /* Full device write or specific chip ? */
598 nrchips
= this->numchips
;
600 nrchips
= chipsel
+ 1;
604 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
608 /* Loop through the chips */
609 for (; chip
< nrchips
; chip
++) {
611 /* There was already a version of the table, reuse the page
612 * This applies for absolute placement too, as we have the
613 * page nr. in td->pages.
615 if (td
->pages
[chip
] != -1) {
616 page
= td
->pages
[chip
];
620 /* Automatic placement of the bad block table */
621 /* Search direction top -> down ? */
622 if (td
->options
& NAND_BBT_LASTBLOCK
) {
623 startblock
= numblocks
* (chip
+ 1) - 1;
626 startblock
= chip
* numblocks
;
630 for (i
= 0; i
< td
->maxblocks
; i
++) {
631 int block
= startblock
+ dir
* i
;
632 /* Check, if the block is bad */
633 switch ((this->bbt
[block
>> 2] >>
634 (2 * (block
& 0x03))) & 0x03) {
640 (this->bbt_erase_shift
- this->page_shift
);
641 /* Check, if the block is used by the mirror table */
642 if (!md
|| md
->pages
[chip
] != page
)
645 printk(KERN_ERR
"No space left to write bad block table\n");
649 /* Set up shift count and masks for the flash table */
650 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
653 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
656 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
659 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
662 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
665 default: return -EINVAL
;
668 bbtoffs
= chip
* (numblocks
>> 2);
670 to
= ((loff_t
) page
) << this->page_shift
;
672 /* Must we save the block contents ? */
673 if (td
->options
& NAND_BBT_SAVECONTENT
) {
674 /* Make it block aligned */
675 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
676 len
= 1 << this->bbt_erase_shift
;
677 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
680 printk(KERN_INFO
"nand_bbt: Error "
681 "reading block for writing "
682 "the bad block table\n");
685 printk(KERN_WARNING
"nand_bbt: ECC error "
686 "while reading block for writing "
687 "bad block table\n");
690 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
691 ops
.oobbuf
= &buf
[len
];
692 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
693 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
696 /* Calc the byte offset in the buffer */
697 pageoffs
= page
- (int)(to
>> this->page_shift
);
698 offs
= pageoffs
<< this->page_shift
;
699 /* Preset the bbt area with 0xff */
700 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
701 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
705 len
= (size_t) (numblocks
>> sft
);
706 /* Make it page aligned ! */
707 len
= (len
+ (mtd
->writesize
- 1)) &
708 ~(mtd
->writesize
- 1);
709 /* Preset the buffer with 0xff */
710 memset(buf
, 0xff, len
+
711 (len
>> this->page_shift
)* mtd
->oobsize
);
714 /* Pattern is located in oob area of first page */
715 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
718 if (td
->options
& NAND_BBT_VERSION
)
719 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
721 /* walk through the memory table */
722 for (i
= 0; i
< numblocks
;) {
724 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
725 for (j
= 0; j
< 4; j
++, i
++) {
726 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
727 /* Do not store the reserved bbt blocks ! */
728 buf
[offs
+ (i
>> sft
)] &=
729 ~(msk
[dat
& 0x03] << sftcnt
);
734 memset(&einfo
, 0, sizeof(einfo
));
736 einfo
.addr
= (unsigned long)to
;
737 einfo
.len
= 1 << this->bbt_erase_shift
;
738 res
= nand_erase_nand(mtd
, &einfo
, 1);
742 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
746 printk(KERN_DEBUG
"Bad block table written to 0x%08x, version "
747 "0x%02X\n", (unsigned int)to
, td
->version
[chip
]);
749 /* Mark it as used */
750 td
->pages
[chip
] = page
;
756 "nand_bbt: Error while writing bad block table %d\n", res
);
761 * nand_memory_bbt - [GENERIC] create a memory based bad block table
762 * @mtd: MTD device structure
763 * @bd: descriptor for the good/bad block search pattern
765 * The function creates a memory based bbt by scanning the device
766 * for manufacturer / software marked good / bad blocks
768 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
770 struct nand_chip
*this = mtd
->priv
;
772 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
773 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
777 * check_create - [GENERIC] create and write bbt(s) if necessary
778 * @mtd: MTD device structure
779 * @buf: temporary buffer
780 * @bd: descriptor for the good/bad block search pattern
782 * The function checks the results of the previous call to read_bbt
783 * and creates / updates the bbt(s) if necessary
784 * Creation is necessary if no bbt was found for the chip/device
785 * Update is necessary if one of the tables is missing or the
786 * version nr. of one table is less than the other
788 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
790 int i
, chips
, writeops
, chipsel
, res
;
791 struct nand_chip
*this = mtd
->priv
;
792 struct nand_bbt_descr
*td
= this->bbt_td
;
793 struct nand_bbt_descr
*md
= this->bbt_md
;
794 struct nand_bbt_descr
*rd
, *rd2
;
796 /* Do we have a bbt per chip ? */
797 if (td
->options
& NAND_BBT_PERCHIP
)
798 chips
= this->numchips
;
802 for (i
= 0; i
< chips
; i
++) {
806 /* Per chip or per device ? */
807 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
808 /* Mirrored table avilable ? */
810 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
815 if (td
->pages
[i
] == -1) {
817 td
->version
[i
] = md
->version
[i
];
822 if (md
->pages
[i
] == -1) {
824 md
->version
[i
] = td
->version
[i
];
829 if (td
->version
[i
] == md
->version
[i
]) {
831 if (!(td
->options
& NAND_BBT_VERSION
))
836 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
838 md
->version
[i
] = td
->version
[i
];
842 td
->version
[i
] = md
->version
[i
];
849 if (td
->pages
[i
] == -1) {
857 /* Create the bad block table by scanning the device ? */
858 if (!(td
->options
& NAND_BBT_CREATE
))
861 /* Create the table in memory by scanning the chip(s) */
862 create_bbt(mtd
, buf
, bd
, chipsel
);
868 /* read back first ? */
870 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
871 /* If they weren't versioned, read both. */
873 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
875 /* Write the bad block table to the device ? */
876 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
877 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
882 /* Write the mirror bad block table to the device ? */
883 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
884 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
893 * mark_bbt_regions - [GENERIC] mark the bad block table regions
894 * @mtd: MTD device structure
895 * @td: bad block table descriptor
897 * The bad block table regions are marked as "bad" to prevent
898 * accidental erasures / writes. The regions are identified by
901 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
903 struct nand_chip
*this = mtd
->priv
;
904 int i
, j
, chips
, block
, nrblocks
, update
;
905 uint8_t oldval
, newval
;
907 /* Do we have a bbt per chip ? */
908 if (td
->options
& NAND_BBT_PERCHIP
) {
909 chips
= this->numchips
;
910 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
913 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
916 for (i
= 0; i
< chips
; i
++) {
917 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
918 !(td
->options
& NAND_BBT_WRITE
)) {
919 if (td
->pages
[i
] == -1)
921 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
923 oldval
= this->bbt
[(block
>> 3)];
924 newval
= oldval
| (0x2 << (block
& 0x06));
925 this->bbt
[(block
>> 3)] = newval
;
926 if ((oldval
!= newval
) && td
->reserved_block_code
)
927 nand_update_bbt(mtd
, block
<< (this->bbt_erase_shift
- 1));
931 if (td
->options
& NAND_BBT_LASTBLOCK
)
932 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
934 block
= i
* nrblocks
;
936 for (j
= 0; j
< td
->maxblocks
; j
++) {
937 oldval
= this->bbt
[(block
>> 3)];
938 newval
= oldval
| (0x2 << (block
& 0x06));
939 this->bbt
[(block
>> 3)] = newval
;
940 if (oldval
!= newval
)
944 /* If we want reserved blocks to be recorded to flash, and some
945 new ones have been marked, then we need to update the stored
946 bbts. This should only happen once. */
947 if (update
&& td
->reserved_block_code
)
948 nand_update_bbt(mtd
, (block
- 2) << (this->bbt_erase_shift
- 1));
953 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
954 * @mtd: MTD device structure
955 * @bd: descriptor for the good/bad block search pattern
957 * The function checks, if a bad block table(s) is/are already
958 * available. If not it scans the device for manufacturer
959 * marked good / bad blocks and writes the bad block table(s) to
960 * the selected place.
962 * The bad block table memory is allocated here. It must be freed
963 * by calling the nand_free_bbt function.
966 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
968 struct nand_chip
*this = mtd
->priv
;
971 struct nand_bbt_descr
*td
= this->bbt_td
;
972 struct nand_bbt_descr
*md
= this->bbt_md
;
974 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
975 /* Allocate memory (2bit per block) and clear the memory bad block table */
976 this->bbt
= kzalloc(len
, GFP_KERNEL
);
978 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
982 /* If no primary table decriptor is given, scan the device
983 * to build a memory based bad block table
986 if ((res
= nand_memory_bbt(mtd
, bd
))) {
987 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
994 /* Allocate a temporary buffer for one eraseblock incl. oob */
995 len
= (1 << this->bbt_erase_shift
);
996 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
999 printk(KERN_ERR
"nand_bbt: Out of memory\n");
1005 /* Is the bbt at a given page ? */
1006 if (td
->options
& NAND_BBT_ABSPAGE
) {
1007 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1009 /* Search the bad block table using a pattern in oob */
1010 res
= search_read_bbts(mtd
, buf
, td
, md
);
1014 res
= check_create(mtd
, buf
, bd
);
1016 /* Prevent the bbt regions from erasing / writing */
1017 mark_bbt_region(mtd
, td
);
1019 mark_bbt_region(mtd
, md
);
1026 * nand_update_bbt - [NAND Interface] update bad block table(s)
1027 * @mtd: MTD device structure
1028 * @offs: the offset of the newly marked block
1030 * The function updates the bad block table(s)
1032 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1034 struct nand_chip
*this = mtd
->priv
;
1035 int len
, res
= 0, writeops
= 0;
1038 struct nand_bbt_descr
*td
= this->bbt_td
;
1039 struct nand_bbt_descr
*md
= this->bbt_md
;
1041 if (!this->bbt
|| !td
)
1044 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1045 /* Allocate a temporary buffer for one eraseblock incl. oob */
1046 len
= (1 << this->bbt_erase_shift
);
1047 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1048 buf
= kmalloc(len
, GFP_KERNEL
);
1050 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1054 writeops
= md
!= NULL
? 0x03 : 0x01;
1056 /* Do we have a bbt per chip ? */
1057 if (td
->options
& NAND_BBT_PERCHIP
) {
1058 chip
= (int)(offs
>> this->chip_shift
);
1065 td
->version
[chip
]++;
1067 md
->version
[chip
]++;
1069 /* Write the bad block table to the device ? */
1070 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1071 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1075 /* Write the mirror bad block table to the device ? */
1076 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1077 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1085 /* Define some generic bad / good block scan pattern which are used
1086 * while scanning a device for factory marked good / bad blocks. */
1087 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1089 static struct nand_bbt_descr smallpage_memorybased
= {
1090 .options
= NAND_BBT_SCAN2NDPAGE
,
1093 .pattern
= scan_ff_pattern
1096 static struct nand_bbt_descr largepage_memorybased
= {
1100 .pattern
= scan_ff_pattern
1103 static struct nand_bbt_descr smallpage_flashbased
= {
1104 .options
= NAND_BBT_SCAN2NDPAGE
,
1107 .pattern
= scan_ff_pattern
1110 static struct nand_bbt_descr largepage_flashbased
= {
1111 .options
= NAND_BBT_SCAN2NDPAGE
,
1114 .pattern
= scan_ff_pattern
1117 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1119 static struct nand_bbt_descr agand_flashbased
= {
1120 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1123 .pattern
= scan_agand_pattern
1126 /* Generic flash bbt decriptors
1128 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1129 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1131 static struct nand_bbt_descr bbt_main_descr
= {
1132 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1133 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1138 .pattern
= bbt_pattern
1141 static struct nand_bbt_descr bbt_mirror_descr
= {
1142 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1143 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1148 .pattern
= mirror_pattern
1152 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1153 * @mtd: MTD device structure
1155 * This function selects the default bad block table
1156 * support for the device and calls the nand_scan_bbt function
1159 int nand_default_bbt(struct mtd_info
*mtd
)
1161 struct nand_chip
*this = mtd
->priv
;
1163 /* Default for AG-AND. We must use a flash based
1164 * bad block table as the devices have factory marked
1165 * _good_ blocks. Erasing those blocks leads to loss
1166 * of the good / bad information, so we _must_ store
1167 * this information in a good / bad table during
1170 if (this->options
& NAND_IS_AND
) {
1171 /* Use the default pattern descriptors */
1172 if (!this->bbt_td
) {
1173 this->bbt_td
= &bbt_main_descr
;
1174 this->bbt_md
= &bbt_mirror_descr
;
1176 this->options
|= NAND_USE_FLASH_BBT
;
1177 return nand_scan_bbt(mtd
, &agand_flashbased
);
1180 /* Is a flash based bad block table requested ? */
1181 if (this->options
& NAND_USE_FLASH_BBT
) {
1182 /* Use the default pattern descriptors */
1183 if (!this->bbt_td
) {
1184 this->bbt_td
= &bbt_main_descr
;
1185 this->bbt_md
= &bbt_mirror_descr
;
1187 if (!this->badblock_pattern
) {
1188 this->badblock_pattern
= (mtd
->writesize
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1191 this->bbt_td
= NULL
;
1192 this->bbt_md
= NULL
;
1193 if (!this->badblock_pattern
) {
1194 this->badblock_pattern
= (mtd
->writesize
> 512) ?
1195 &largepage_memorybased
: &smallpage_memorybased
;
1198 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1202 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1203 * @mtd: MTD device structure
1204 * @offs: offset in the device
1205 * @allowbbt: allow access to bad block table region
1208 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1210 struct nand_chip
*this = mtd
->priv
;
1214 /* Get block number * 2 */
1215 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1216 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1218 MTDDEBUG (MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1219 "(block %d) 0x%02x\n", (unsigned int)offs
, res
, block
>> 1);
1227 return allowbbt
? 0 : 1;
1232 /* XXX U-BOOT XXX */
1234 EXPORT_SYMBOL(nand_scan_bbt
);
1235 EXPORT_SYMBOL(nand_default_bbt
);