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24 * If one of the bbt's is out of date or does not exist it is (re)created.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
55 #include <linux/slab.h>
56 #include <linux/types.h>
57 #include <linux/mtd/mtd.h>
58 #include <linux/mtd/nand.h>
59 #include <linux/mtd/nand_ecc.h>
60 #include <linux/mtd/compatmac.h>
61 #include <linux/bitops.h>
62 #include <linux/delay.h>
63 #include <linux/vmalloc.h>
66 * check_pattern - [GENERIC] check if a pattern is in the buffer
67 * @buf: the buffer to search
68 * @len: the length of buffer to search
69 * @paglen: the pagelength
70 * @td: search pattern descriptor
72 * Check for a pattern at the given place. Used to search bad block
73 * tables and good / bad block identifiers.
74 * If the SCAN_EMPTY option is set then check, if all bytes except the
75 * pattern area contain 0xff
78 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
83 end
= paglen
+ td
->offs
;
84 if (td
->options
& NAND_BBT_SCANEMPTY
) {
85 for (i
= 0; i
< end
; i
++) {
92 /* Compare the pattern */
93 for (i
= 0; i
< td
->len
; i
++) {
94 if (p
[i
] != td
->pattern
[i
])
98 if (td
->options
& NAND_BBT_SCANEMPTY
) {
101 for (i
= end
; i
< len
; i
++) {
110 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
111 * @buf: the buffer to search
112 * @td: search pattern descriptor
114 * Check for a pattern at the given place. Used to search bad block
115 * tables and good / bad block identifiers. Same as check_pattern, but
116 * no optional empty check
119 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
124 /* Compare the pattern */
125 for (i
= 0; i
< td
->len
; i
++) {
126 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
133 * read_bbt - [GENERIC] Read the bad block table starting from page
134 * @mtd: MTD device structure
135 * @buf: temporary buffer
136 * @page: the starting page
137 * @num: the number of bbt descriptors to read
138 * @bits: number of bits per block
139 * @offs: offset in the memory table
140 * @reserved_block_code: Pattern to identify reserved blocks
142 * Read the bad block table starting from page.
145 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
146 int bits
, int offs
, int reserved_block_code
)
148 int res
, i
, j
, act
= 0;
149 struct nand_chip
*this = mtd
->priv
;
150 size_t retlen
, len
, totlen
;
152 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
154 totlen
= (num
* bits
) >> 3;
155 from
= ((loff_t
) page
) << this->page_shift
;
158 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
159 res
= mtd
->read_ecc(mtd
, from
, len
, &retlen
, buf
, NULL
, this->autooob
);
162 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
165 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
169 for (i
= 0; i
< len
; i
++) {
170 uint8_t dat
= buf
[i
];
171 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
172 uint8_t tmp
= (dat
>> j
) & msk
;
175 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
176 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%08x\n",
177 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
178 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
181 /* Leave it for now, if its matured we can move this
182 * message to MTD_DEBUG_LEVEL0 */
183 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%08x\n",
184 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
185 /* Factory marked bad or worn out ? */
187 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
189 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
199 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
200 * @mtd: MTD device structure
201 * @buf: temporary buffer
202 * @td: descriptor for the bad block table
203 * @chip: read the table for a specific chip, -1 read all chips.
204 * Applies only if NAND_BBT_PERCHIP option is set
206 * Read the bad block table for all chips starting at a given page
207 * We assume that the bbt bits are in consecutive order.
209 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
211 struct nand_chip
*this = mtd
->priv
;
215 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
216 if (td
->options
& NAND_BBT_PERCHIP
) {
218 for (i
= 0; i
< this->numchips
; i
++) {
219 if (chip
== -1 || chip
== i
)
220 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
223 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
226 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
234 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
235 * @mtd: MTD device structure
236 * @buf: temporary buffer
237 * @td: descriptor for the bad block table
238 * @md: descriptor for the bad block table mirror
240 * Read the bad block table(s) for all chips starting at a given page
241 * We assume that the bbt bits are in consecutive order.
244 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
246 struct nand_chip
*this = mtd
->priv
;
248 /* Read the primary version, if available */
249 if (td
->options
& NAND_BBT_VERSION
) {
250 nand_read_raw(mtd
, buf
, td
->pages
[0] << this->page_shift
, mtd
->oobblock
, mtd
->oobsize
);
251 td
->version
[0] = buf
[mtd
->oobblock
+ td
->veroffs
];
252 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n", td
->pages
[0], td
->version
[0]);
255 /* Read the mirror version, if available */
256 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
257 nand_read_raw(mtd
, buf
, md
->pages
[0] << this->page_shift
, mtd
->oobblock
, mtd
->oobsize
);
258 md
->version
[0] = buf
[mtd
->oobblock
+ md
->veroffs
];
259 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n", md
->pages
[0], md
->version
[0]);
266 * create_bbt - [GENERIC] Create a bad block table by scanning the device
267 * @mtd: MTD device structure
268 * @buf: temporary buffer
269 * @bd: descriptor for the good/bad block search pattern
270 * @chip: create the table for a specific chip, -1 read all chips.
271 * Applies only if NAND_BBT_PERCHIP option is set
273 * Create a bad block table by scanning the device
274 * for the given good/bad block identify pattern
276 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
, int chip
)
278 struct nand_chip
*this = mtd
->priv
;
279 int i
, j
, numblocks
, len
, scanlen
;
282 size_t readlen
, ooblen
;
284 printk(KERN_INFO
"Scanning device for bad blocks\n");
286 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
287 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
289 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
295 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
296 /* We need only read few bytes from the OOB area */
297 scanlen
= ooblen
= 0;
300 /* Full page content should be read */
301 scanlen
= mtd
->oobblock
+ mtd
->oobsize
;
302 readlen
= len
* mtd
->oobblock
;
303 ooblen
= len
* mtd
->oobsize
;
307 /* Note that numblocks is 2 * (real numblocks) here, see i+=2 below as it
308 * makes shifting and masking less painful */
309 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
313 if (chip
>= this->numchips
) {
314 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
315 chip
+ 1, this->numchips
);
318 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
319 startblock
= chip
* numblocks
;
320 numblocks
+= startblock
;
321 from
= startblock
<< (this->bbt_erase_shift
- 1);
324 for (i
= startblock
; i
< numblocks
;) {
327 if (bd
->options
& NAND_BBT_SCANEMPTY
)
328 if ((ret
= nand_read_raw(mtd
, buf
, from
, readlen
, ooblen
)))
331 for (j
= 0; j
< len
; j
++) {
332 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
335 /* Read the full oob until read_oob is fixed to
336 * handle single byte reads for 16 bit buswidth */
337 ret
= mtd
->read_oob(mtd
, from
+ j
* mtd
->oobblock
, mtd
->oobsize
, &retlen
, buf
);
341 if (check_short_pattern(buf
, bd
)) {
342 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
343 printk(KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
344 i
>> 1, (unsigned int)from
);
348 if (check_pattern(&buf
[j
* scanlen
], scanlen
, mtd
->oobblock
, bd
)) {
349 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
350 printk(KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
351 i
>> 1, (unsigned int)from
);
357 from
+= (1 << this->bbt_erase_shift
);
363 * search_bbt - [GENERIC] scan the device for a specific bad block table
364 * @mtd: MTD device structure
365 * @buf: temporary buffer
366 * @td: descriptor for the bad block table
368 * Read the bad block table by searching for a given ident pattern.
369 * Search is preformed either from the beginning up or from the end of
370 * the device downwards. The search starts always at the start of a
372 * If the option NAND_BBT_PERCHIP is given, each chip is searched
373 * for a bbt, which contains the bad block information of this chip.
374 * This is necessary to provide support for certain DOC devices.
376 * The bbt ident pattern resides in the oob area of the first page
379 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
381 struct nand_chip
*this = mtd
->priv
;
383 int bits
, startblock
, block
, dir
;
384 int scanlen
= mtd
->oobblock
+ mtd
->oobsize
;
387 /* Search direction top -> down ? */
388 if (td
->options
& NAND_BBT_LASTBLOCK
) {
389 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
396 /* Do we have a bbt per chip ? */
397 if (td
->options
& NAND_BBT_PERCHIP
) {
398 chips
= this->numchips
;
399 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
400 startblock
&= bbtblocks
- 1;
403 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
406 /* Number of bits for each erase block in the bbt */
407 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
409 for (i
= 0; i
< chips
; i
++) {
410 /* Reset version information */
413 /* Scan the maximum number of blocks */
414 for (block
= 0; block
< td
->maxblocks
; block
++) {
415 int actblock
= startblock
+ dir
* block
;
416 /* Read first page */
417 nand_read_raw(mtd
, buf
, actblock
<< this->bbt_erase_shift
, mtd
->oobblock
, mtd
->oobsize
);
418 if (!check_pattern(buf
, scanlen
, mtd
->oobblock
, td
)) {
419 td
->pages
[i
] = actblock
<< (this->bbt_erase_shift
- this->page_shift
);
420 if (td
->options
& NAND_BBT_VERSION
) {
421 td
->version
[i
] = buf
[mtd
->oobblock
+ td
->veroffs
];
426 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
428 /* Check, if we found a bbt for each requested chip */
429 for (i
= 0; i
< chips
; i
++) {
430 if (td
->pages
[i
] == -1)
431 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
433 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
440 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
441 * @mtd: MTD device structure
442 * @buf: temporary buffer
443 * @td: descriptor for the bad block table
444 * @md: descriptor for the bad block table mirror
446 * Search and read the bad block table(s)
448 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
450 /* Search the primary table */
451 search_bbt(mtd
, buf
, td
);
453 /* Search the mirror table */
455 search_bbt(mtd
, buf
, md
);
457 /* Force result check */
462 * write_bbt - [GENERIC] (Re)write the bad block table
464 * @mtd: MTD device structure
465 * @buf: temporary buffer
466 * @td: descriptor for the bad block table
467 * @md: descriptor for the bad block table mirror
468 * @chipsel: selector for a specific chip, -1 for all
470 * (Re)write the bad block table
473 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
474 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
, int chipsel
)
476 struct nand_chip
*this = mtd
->priv
;
477 struct nand_oobinfo oobinfo
;
478 struct erase_info einfo
;
479 int i
, j
, res
, chip
= 0;
480 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
481 int nrchips
, bbtoffs
, pageoffs
;
483 uint8_t rcode
= td
->reserved_block_code
;
484 size_t retlen
, len
= 0;
489 /* Write bad block table per chip rather than per device ? */
490 if (td
->options
& NAND_BBT_PERCHIP
) {
491 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
492 /* Full device write or specific chip ? */
494 nrchips
= this->numchips
;
496 nrchips
= chipsel
+ 1;
500 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
504 /* Loop through the chips */
505 for (; chip
< nrchips
; chip
++) {
507 /* There was already a version of the table, reuse the page
508 * This applies for absolute placement too, as we have the
509 * page nr. in td->pages.
511 if (td
->pages
[chip
] != -1) {
512 page
= td
->pages
[chip
];
516 /* Automatic placement of the bad block table */
517 /* Search direction top -> down ? */
518 if (td
->options
& NAND_BBT_LASTBLOCK
) {
519 startblock
= numblocks
* (chip
+ 1) - 1;
522 startblock
= chip
* numblocks
;
526 for (i
= 0; i
< td
->maxblocks
; i
++) {
527 int block
= startblock
+ dir
* i
;
528 /* Check, if the block is bad */
529 switch ((this->bbt
[block
>> 2] >> (2 * (block
& 0x03))) & 0x03) {
534 page
= block
<< (this->bbt_erase_shift
- this->page_shift
);
535 /* Check, if the block is used by the mirror table */
536 if (!md
|| md
->pages
[chip
] != page
)
539 printk(KERN_ERR
"No space left to write bad block table\n");
543 /* Set up shift count and masks for the flash table */
544 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
546 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01; msk
[2] = ~rcode
; msk
[3] = 0x01; break;
547 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01; msk
[2] = ~rcode
; msk
[3] = 0x03; break;
548 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C; msk
[2] = ~rcode
; msk
[3] = 0x0f; break;
549 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F; msk
[2] = ~rcode
; msk
[3] = 0xff; break;
550 default: return -EINVAL
;
553 bbtoffs
= chip
* (numblocks
>> 2);
555 to
= ((loff_t
) page
) << this->page_shift
;
557 memcpy(&oobinfo
, this->autooob
, sizeof(oobinfo
));
558 oobinfo
.useecc
= MTD_NANDECC_PLACEONLY
;
560 /* Must we save the block contents ? */
561 if (td
->options
& NAND_BBT_SAVECONTENT
) {
562 /* Make it block aligned */
563 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
564 len
= 1 << this->bbt_erase_shift
;
565 res
= mtd
->read_ecc(mtd
, to
, len
, &retlen
, buf
, &buf
[len
], &oobinfo
);
569 "nand_bbt: Error reading block for writing the bad block table\n");
572 printk(KERN_WARNING
"nand_bbt: ECC error while reading block for writing bad block table\n");
574 /* Calc the byte offset in the buffer */
575 pageoffs
= page
- (int)(to
>> this->page_shift
);
576 offs
= pageoffs
<< this->page_shift
;
577 /* Preset the bbt area with 0xff */
578 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
579 /* Preset the bbt's oob area with 0xff */
580 memset(&buf
[len
+ pageoffs
* mtd
->oobsize
], 0xff,
581 ((len
>> this->page_shift
) - pageoffs
) * mtd
->oobsize
);
582 if (td
->options
& NAND_BBT_VERSION
) {
583 buf
[len
+ (pageoffs
* mtd
->oobsize
) + td
->veroffs
] = td
->version
[chip
];
587 len
= (size_t) (numblocks
>> sft
);
588 /* Make it page aligned ! */
589 len
= (len
+ (mtd
->oobblock
- 1)) & ~(mtd
->oobblock
- 1);
590 /* Preset the buffer with 0xff */
591 memset(buf
, 0xff, len
+ (len
>> this->page_shift
) * mtd
->oobsize
);
593 /* Pattern is located in oob area of first page */
594 memcpy(&buf
[len
+ td
->offs
], td
->pattern
, td
->len
);
595 if (td
->options
& NAND_BBT_VERSION
) {
596 buf
[len
+ td
->veroffs
] = td
->version
[chip
];
600 /* walk through the memory table */
601 for (i
= 0; i
< numblocks
;) {
603 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
604 for (j
= 0; j
< 4; j
++, i
++) {
605 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
606 /* Do not store the reserved bbt blocks ! */
607 buf
[offs
+ (i
>> sft
)] &= ~(msk
[dat
& 0x03] << sftcnt
);
612 memset(&einfo
, 0, sizeof(einfo
));
614 einfo
.addr
= (unsigned long)to
;
615 einfo
.len
= 1 << this->bbt_erase_shift
;
616 res
= nand_erase_nand(mtd
, &einfo
, 1);
618 printk(KERN_WARNING
"nand_bbt: Error during block erase: %d\n", res
);
622 res
= mtd
->write_ecc(mtd
, to
, len
, &retlen
, buf
, &buf
[len
], &oobinfo
);
624 printk(KERN_WARNING
"nand_bbt: Error while writing bad block table %d\n", res
);
627 printk(KERN_DEBUG
"Bad block table written to 0x%08x, version 0x%02X\n",
628 (unsigned int)to
, td
->version
[chip
]);
630 /* Mark it as used */
631 td
->pages
[chip
] = page
;
637 * nand_memory_bbt - [GENERIC] create a memory based bad block table
638 * @mtd: MTD device structure
639 * @bd: descriptor for the good/bad block search pattern
641 * The function creates a memory based bbt by scanning the device
642 * for manufacturer / software marked good / bad blocks
644 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
646 struct nand_chip
*this = mtd
->priv
;
648 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
649 return create_bbt(mtd
, this->data_buf
, bd
, -1);
653 * check_create - [GENERIC] create and write bbt(s) if necessary
654 * @mtd: MTD device structure
655 * @buf: temporary buffer
656 * @bd: descriptor for the good/bad block search pattern
658 * The function checks the results of the previous call to read_bbt
659 * and creates / updates the bbt(s) if necessary
660 * Creation is necessary if no bbt was found for the chip/device
661 * Update is necessary if one of the tables is missing or the
662 * version nr. of one table is less than the other
664 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
666 int i
, chips
, writeops
, chipsel
, res
;
667 struct nand_chip
*this = mtd
->priv
;
668 struct nand_bbt_descr
*td
= this->bbt_td
;
669 struct nand_bbt_descr
*md
= this->bbt_md
;
670 struct nand_bbt_descr
*rd
, *rd2
;
672 /* Do we have a bbt per chip ? */
673 if (td
->options
& NAND_BBT_PERCHIP
)
674 chips
= this->numchips
;
678 for (i
= 0; i
< chips
; i
++) {
682 /* Per chip or per device ? */
683 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
684 /* Mirrored table avilable ? */
686 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
691 if (td
->pages
[i
] == -1) {
693 td
->version
[i
] = md
->version
[i
];
698 if (md
->pages
[i
] == -1) {
700 md
->version
[i
] = td
->version
[i
];
705 if (td
->version
[i
] == md
->version
[i
]) {
707 if (!(td
->options
& NAND_BBT_VERSION
))
712 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
714 md
->version
[i
] = td
->version
[i
];
718 td
->version
[i
] = md
->version
[i
];
725 if (td
->pages
[i
] == -1) {
733 /* Create the bad block table by scanning the device ? */
734 if (!(td
->options
& NAND_BBT_CREATE
))
737 /* Create the table in memory by scanning the chip(s) */
738 create_bbt(mtd
, buf
, bd
, chipsel
);
744 /* read back first ? */
746 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
747 /* If they weren't versioned, read both. */
749 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
751 /* Write the bad block table to the device ? */
752 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
753 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
758 /* Write the mirror bad block table to the device ? */
759 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
760 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
769 * mark_bbt_regions - [GENERIC] mark the bad block table regions
770 * @mtd: MTD device structure
771 * @td: bad block table descriptor
773 * The bad block table regions are marked as "bad" to prevent
774 * accidental erasures / writes. The regions are identified by
777 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
779 struct nand_chip
*this = mtd
->priv
;
780 int i
, j
, chips
, block
, nrblocks
, update
;
781 uint8_t oldval
, newval
;
783 /* Do we have a bbt per chip ? */
784 if (td
->options
& NAND_BBT_PERCHIP
) {
785 chips
= this->numchips
;
786 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
789 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
792 for (i
= 0; i
< chips
; i
++) {
793 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
794 !(td
->options
& NAND_BBT_WRITE
)) {
795 if (td
->pages
[i
] == -1)
797 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
799 oldval
= this->bbt
[(block
>> 3)];
800 newval
= oldval
| (0x2 << (block
& 0x06));
801 this->bbt
[(block
>> 3)] = newval
;
802 if ((oldval
!= newval
) && td
->reserved_block_code
)
803 nand_update_bbt(mtd
, block
<< (this->bbt_erase_shift
- 1));
807 if (td
->options
& NAND_BBT_LASTBLOCK
)
808 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
810 block
= i
* nrblocks
;
812 for (j
= 0; j
< td
->maxblocks
; j
++) {
813 oldval
= this->bbt
[(block
>> 3)];
814 newval
= oldval
| (0x2 << (block
& 0x06));
815 this->bbt
[(block
>> 3)] = newval
;
816 if (oldval
!= newval
)
820 /* If we want reserved blocks to be recorded to flash, and some
821 new ones have been marked, then we need to update the stored
822 bbts. This should only happen once. */
823 if (update
&& td
->reserved_block_code
)
824 nand_update_bbt(mtd
, (block
- 2) << (this->bbt_erase_shift
- 1));
829 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
830 * @mtd: MTD device structure
831 * @bd: descriptor for the good/bad block search pattern
833 * The function checks, if a bad block table(s) is/are already
834 * available. If not it scans the device for manufacturer
835 * marked good / bad blocks and writes the bad block table(s) to
836 * the selected place.
838 * The bad block table memory is allocated here. It must be freed
839 * by calling the nand_free_bbt function.
842 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
844 struct nand_chip
*this = mtd
->priv
;
847 struct nand_bbt_descr
*td
= this->bbt_td
;
848 struct nand_bbt_descr
*md
= this->bbt_md
;
850 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
851 /* Allocate memory (2bit per block) */
852 this->bbt
= kmalloc(len
, GFP_KERNEL
);
854 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
857 /* Clear the memory bad block table */
858 memset(this->bbt
, 0x00, len
);
860 /* If no primary table decriptor is given, scan the device
861 * to build a memory based bad block table
864 if ((res
= nand_memory_bbt(mtd
, bd
))) {
865 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
872 /* Allocate a temporary buffer for one eraseblock incl. oob */
873 len
= (1 << this->bbt_erase_shift
);
874 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
877 printk(KERN_ERR
"nand_bbt: Out of memory\n");
883 /* Is the bbt at a given page ? */
884 if (td
->options
& NAND_BBT_ABSPAGE
) {
885 res
= read_abs_bbts(mtd
, buf
, td
, md
);
887 /* Search the bad block table using a pattern in oob */
888 res
= search_read_bbts(mtd
, buf
, td
, md
);
892 res
= check_create(mtd
, buf
, bd
);
894 /* Prevent the bbt regions from erasing / writing */
895 mark_bbt_region(mtd
, td
);
897 mark_bbt_region(mtd
, md
);
904 * nand_update_bbt - [NAND Interface] update bad block table(s)
905 * @mtd: MTD device structure
906 * @offs: the offset of the newly marked block
908 * The function updates the bad block table(s)
910 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
912 struct nand_chip
*this = mtd
->priv
;
913 int len
, res
= 0, writeops
= 0;
916 struct nand_bbt_descr
*td
= this->bbt_td
;
917 struct nand_bbt_descr
*md
= this->bbt_md
;
919 if (!this->bbt
|| !td
)
922 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
923 /* Allocate a temporary buffer for one eraseblock incl. oob */
924 len
= (1 << this->bbt_erase_shift
);
925 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
926 buf
= kmalloc(len
, GFP_KERNEL
);
928 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
932 writeops
= md
!= NULL
? 0x03 : 0x01;
934 /* Do we have a bbt per chip ? */
935 if (td
->options
& NAND_BBT_PERCHIP
) {
936 chip
= (int)(offs
>> this->chip_shift
);
947 /* Write the bad block table to the device ? */
948 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
949 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
953 /* Write the mirror bad block table to the device ? */
954 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
955 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
963 /* Define some generic bad / good block scan pattern which are used
964 * while scanning a device for factory marked good / bad blocks. */
965 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
967 static struct nand_bbt_descr smallpage_memorybased
= {
968 .options
= NAND_BBT_SCAN2NDPAGE
,
971 .pattern
= scan_ff_pattern
974 static struct nand_bbt_descr largepage_memorybased
= {
978 .pattern
= scan_ff_pattern
981 static struct nand_bbt_descr smallpage_flashbased
= {
982 .options
= NAND_BBT_SCAN2NDPAGE
,
985 .pattern
= scan_ff_pattern
988 static struct nand_bbt_descr largepage_flashbased
= {
989 .options
= NAND_BBT_SCAN2NDPAGE
,
992 .pattern
= scan_ff_pattern
995 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
997 static struct nand_bbt_descr agand_flashbased
= {
998 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1001 .pattern
= scan_agand_pattern
1004 /* Generic flash bbt decriptors
1006 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1007 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1009 static struct nand_bbt_descr bbt_main_descr
= {
1010 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1011 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1016 .pattern
= bbt_pattern
1019 static struct nand_bbt_descr bbt_mirror_descr
= {
1020 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1021 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1026 .pattern
= mirror_pattern
1030 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1031 * @mtd: MTD device structure
1033 * This function selects the default bad block table
1034 * support for the device and calls the nand_scan_bbt function
1037 int nand_default_bbt(struct mtd_info
*mtd
)
1039 struct nand_chip
*this = mtd
->priv
;
1041 /* Default for AG-AND. We must use a flash based
1042 * bad block table as the devices have factory marked
1043 * _good_ blocks. Erasing those blocks leads to loss
1044 * of the good / bad information, so we _must_ store
1045 * this information in a good / bad table during
1048 if (this->options
& NAND_IS_AND
) {
1049 /* Use the default pattern descriptors */
1050 if (!this->bbt_td
) {
1051 this->bbt_td
= &bbt_main_descr
;
1052 this->bbt_md
= &bbt_mirror_descr
;
1054 this->options
|= NAND_USE_FLASH_BBT
;
1055 return nand_scan_bbt(mtd
, &agand_flashbased
);
1058 /* Is a flash based bad block table requested ? */
1059 if (this->options
& NAND_USE_FLASH_BBT
) {
1060 /* Use the default pattern descriptors */
1061 if (!this->bbt_td
) {
1062 this->bbt_td
= &bbt_main_descr
;
1063 this->bbt_md
= &bbt_mirror_descr
;
1065 if (!this->badblock_pattern
) {
1066 this->badblock_pattern
= (mtd
->oobblock
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1069 this->bbt_td
= NULL
;
1070 this->bbt_md
= NULL
;
1071 if (!this->badblock_pattern
) {
1072 this->badblock_pattern
= (mtd
->oobblock
> 512) ?
1073 &largepage_memorybased
: &smallpage_memorybased
;
1076 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1080 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1081 * @mtd: MTD device structure
1082 * @offs: offset in the device
1083 * @allowbbt: allow access to bad block table region
1086 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1088 struct nand_chip
*this = mtd
->priv
;
1092 /* Get block number * 2 */
1093 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1094 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1096 DEBUG(MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1097 (unsigned int)offs
, block
>> 1, res
);
1105 return allowbbt
? 0 : 1;
1110 EXPORT_SYMBOL(nand_scan_bbt
);
1111 EXPORT_SYMBOL(nand_default_bbt
);