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 1.31 2005/02/16 17:09:36 dedekind 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24 * If one of the bbt's is out of date or does not exist it is (re)created.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 neccecary 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>
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 if (td
->options
& NAND_BBT_SCANEMPTY
) {
84 end
= paglen
+ td
->offs
;
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 * read_bbt - [GENERIC] Read the bad block table starting from page
111 * @mtd: MTD device structure
112 * @buf: temporary buffer
113 * @page: the starting page
114 * @num: the number of bbt descriptors to read
115 * @bits: number of bits per block
116 * @offs: offset in the memory table
117 * @reserved_block_code: Pattern to identify reserved blocks
119 * Read the bad block table starting from page.
122 static int read_bbt (struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
123 int bits
, int offs
, int reserved_block_code
)
125 int res
, i
, j
, act
= 0;
126 struct nand_chip
*this = mtd
->priv
;
127 size_t retlen
, len
, totlen
;
129 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
131 totlen
= (num
* bits
) >> 3;
132 from
= ((loff_t
)page
) << this->page_shift
;
135 len
= min (totlen
, (size_t) (1 << this->bbt_erase_shift
));
136 res
= mtd
->read_ecc (mtd
, from
, len
, &retlen
, buf
, NULL
, this->autooob
);
139 printk (KERN_INFO
"nand_bbt: Error reading bad block table\n");
142 printk (KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
146 for (i
= 0; i
< len
; i
++) {
147 uint8_t dat
= buf
[i
];
148 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
149 uint8_t tmp
= (dat
>> j
) & msk
;
152 if (reserved_block_code
&&
153 (tmp
== reserved_block_code
)) {
154 printk (KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%08x\n",
155 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
156 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
159 /* Leave it for now, if its matured we can move this
160 * message to MTD_DEBUG_LEVEL0 */
161 printk (KERN_DEBUG
"nand_read_bbt: Bad block at 0x%08x\n",
162 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
163 /* Factory marked bad or worn out ? */
165 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
167 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
177 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
178 * @mtd: MTD device structure
179 * @buf: temporary buffer
180 * @td: descriptor for the bad block table
181 * @chip: read the table for a specific chip, -1 read all chips.
182 * Applies only if NAND_BBT_PERCHIP option is set
184 * Read the bad block table for all chips starting at a given page
185 * We assume that the bbt bits are in consecutive order.
187 static int read_abs_bbt (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
189 struct nand_chip
*this = mtd
->priv
;
193 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
194 if (td
->options
& NAND_BBT_PERCHIP
) {
196 for (i
= 0; i
< this->numchips
; i
++) {
197 if (chip
== -1 || chip
== i
)
198 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
201 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
204 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
212 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
213 * @mtd: MTD device structure
214 * @buf: temporary buffer
215 * @td: descriptor for the bad block table
216 * @md: descriptor for the bad block table mirror
218 * Read the bad block table(s) for all chips starting at a given page
219 * We assume that the bbt bits are in consecutive order.
222 static int read_abs_bbts (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
,
223 struct nand_bbt_descr
*md
)
225 struct nand_chip
*this = mtd
->priv
;
227 /* Read the primary version, if available */
228 if (td
->options
& NAND_BBT_VERSION
) {
229 nand_read_raw (mtd
, buf
, td
->pages
[0] << this->page_shift
, mtd
->oobblock
, mtd
->oobsize
);
230 td
->version
[0] = buf
[mtd
->oobblock
+ td
->veroffs
];
231 printk (KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n", td
->pages
[0], td
->version
[0]);
234 /* Read the mirror version, if available */
235 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
236 nand_read_raw (mtd
, buf
, md
->pages
[0] << this->page_shift
, mtd
->oobblock
, mtd
->oobsize
);
237 md
->version
[0] = buf
[mtd
->oobblock
+ md
->veroffs
];
238 printk (KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n", md
->pages
[0], md
->version
[0]);
245 * create_bbt - [GENERIC] Create a bad block table by scanning the device
246 * @mtd: MTD device structure
247 * @buf: temporary buffer
248 * @bd: descriptor for the good/bad block search pattern
249 * @chip: create the table for a specific chip, -1 read all chips.
250 * Applies only if NAND_BBT_PERCHIP option is set
252 * Create a bad block table by scanning the device
253 * for the given good/bad block identify pattern
255 static int create_bbt (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
, int chip
)
257 struct nand_chip
*this = mtd
->priv
;
258 int i
, j
, numblocks
, len
, scanlen
;
261 size_t readlen
, ooblen
;
263 printk (KERN_INFO
"Scanning device for bad blocks\n");
265 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
266 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
268 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
274 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
275 /* We need only read few bytes from the OOB area */
276 scanlen
= ooblen
= 0;
279 /* Full page content should be read */
280 scanlen
= mtd
->oobblock
+ mtd
->oobsize
;
281 readlen
= len
* mtd
->oobblock
;
282 ooblen
= len
* mtd
->oobsize
;
286 /* Note that numblocks is 2 * (real numblocks) here, see i+=2 below as it
287 * makes shifting and masking less painful */
288 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
292 if (chip
>= this->numchips
) {
293 printk (KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
294 chip
+ 1, this->numchips
);
297 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
298 startblock
= chip
* numblocks
;
299 numblocks
+= startblock
;
300 from
= startblock
<< (this->bbt_erase_shift
- 1);
303 for (i
= startblock
; i
< numblocks
;) {
306 if (bd
->options
& NAND_BBT_SCANEMPTY
)
307 if ((ret
= nand_read_raw (mtd
, buf
, from
, readlen
, ooblen
)))
310 for (j
= 0; j
< len
; j
++) {
311 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
314 /* No need to read pages fully, just read required OOB bytes */
315 ret
= mtd
->read_oob(mtd
, from
+ j
* mtd
->oobblock
+ bd
->offs
,
316 readlen
, &retlen
, &buf
[0]);
320 if (check_pattern (&buf
[j
* scanlen
], scanlen
, mtd
->oobblock
, bd
)) {
321 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
322 printk (KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
323 i
>> 1, (unsigned int) from
);
328 from
+= (1 << this->bbt_erase_shift
);
335 * search_bbt - [GENERIC] scan the device for a specific bad block table
336 * @mtd: MTD device structure
337 * @buf: temporary buffer
338 * @td: descriptor for the bad block table
340 * Read the bad block table by searching for a given ident pattern.
341 * Search is preformed either from the beginning up or from the end of
342 * the device downwards. The search starts always at the start of a
344 * If the option NAND_BBT_PERCHIP is given, each chip is searched
345 * for a bbt, which contains the bad block information of this chip.
346 * This is neccecary to provide support for certain DOC devices.
348 * The bbt ident pattern resides in the oob area of the first page
351 static int search_bbt (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
353 struct nand_chip
*this = mtd
->priv
;
355 int bits
, startblock
, block
, dir
;
356 int scanlen
= mtd
->oobblock
+ mtd
->oobsize
;
359 /* Search direction top -> down ? */
360 if (td
->options
& NAND_BBT_LASTBLOCK
) {
361 startblock
= (mtd
->size
>> this->bbt_erase_shift
) -1;
368 /* Do we have a bbt per chip ? */
369 if (td
->options
& NAND_BBT_PERCHIP
) {
370 chips
= this->numchips
;
371 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
372 startblock
&= bbtblocks
- 1;
375 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
378 /* Number of bits for each erase block in the bbt */
379 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
381 for (i
= 0; i
< chips
; i
++) {
382 /* Reset version information */
385 /* Scan the maximum number of blocks */
386 for (block
= 0; block
< td
->maxblocks
; block
++) {
387 int actblock
= startblock
+ dir
* block
;
388 /* Read first page */
389 nand_read_raw (mtd
, buf
, actblock
<< this->bbt_erase_shift
, mtd
->oobblock
, mtd
->oobsize
);
390 if (!check_pattern(buf
, scanlen
, mtd
->oobblock
, td
)) {
391 td
->pages
[i
] = actblock
<< (this->bbt_erase_shift
- this->page_shift
);
392 if (td
->options
& NAND_BBT_VERSION
) {
393 td
->version
[i
] = buf
[mtd
->oobblock
+ td
->veroffs
];
398 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
400 /* Check, if we found a bbt for each requested chip */
401 for (i
= 0; i
< chips
; i
++) {
402 if (td
->pages
[i
] == -1)
403 printk (KERN_WARNING
"Bad block table not found for chip %d\n", i
);
405 printk (KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
], td
->version
[i
]);
411 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
412 * @mtd: MTD device structure
413 * @buf: temporary buffer
414 * @td: descriptor for the bad block table
415 * @md: descriptor for the bad block table mirror
417 * Search and read the bad block table(s)
419 static int search_read_bbts (struct mtd_info
*mtd
, uint8_t *buf
,
420 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
422 /* Search the primary table */
423 search_bbt (mtd
, buf
, td
);
425 /* Search the mirror table */
427 search_bbt (mtd
, buf
, md
);
429 /* Force result check */
435 * write_bbt - [GENERIC] (Re)write the bad block table
437 * @mtd: MTD device structure
438 * @buf: temporary buffer
439 * @td: descriptor for the bad block table
440 * @md: descriptor for the bad block table mirror
441 * @chipsel: selector for a specific chip, -1 for all
443 * (Re)write the bad block table
446 static int write_bbt (struct mtd_info
*mtd
, uint8_t *buf
,
447 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
, int chipsel
)
449 struct nand_chip
*this = mtd
->priv
;
450 struct nand_oobinfo oobinfo
;
451 struct erase_info einfo
;
452 int i
, j
, res
, chip
= 0;
453 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
454 int nrchips
, bbtoffs
, pageoffs
;
456 uint8_t rcode
= td
->reserved_block_code
;
457 size_t retlen
, len
= 0;
462 /* Write bad block table per chip rather than per device ? */
463 if (td
->options
& NAND_BBT_PERCHIP
) {
464 numblocks
= (int) (this->chipsize
>> this->bbt_erase_shift
);
465 /* Full device write or specific chip ? */
467 nrchips
= this->numchips
;
469 nrchips
= chipsel
+ 1;
473 numblocks
= (int) (mtd
->size
>> this->bbt_erase_shift
);
477 /* Loop through the chips */
478 for (; chip
< nrchips
; chip
++) {
480 /* There was already a version of the table, reuse the page
481 * This applies for absolute placement too, as we have the
482 * page nr. in td->pages.
484 if (td
->pages
[chip
] != -1) {
485 page
= td
->pages
[chip
];
489 /* Automatic placement of the bad block table */
490 /* Search direction top -> down ? */
491 if (td
->options
& NAND_BBT_LASTBLOCK
) {
492 startblock
= numblocks
* (chip
+ 1) - 1;
495 startblock
= chip
* numblocks
;
499 for (i
= 0; i
< td
->maxblocks
; i
++) {
500 int block
= startblock
+ dir
* i
;
501 /* Check, if the block is bad */
502 switch ((this->bbt
[block
>> 2] >> (2 * (block
& 0x03))) & 0x03) {
507 page
= block
<< (this->bbt_erase_shift
- this->page_shift
);
508 /* Check, if the block is used by the mirror table */
509 if (!md
|| md
->pages
[chip
] != page
)
512 printk (KERN_ERR
"No space left to write bad block table\n");
516 /* Set up shift count and masks for the flash table */
517 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
519 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01; msk
[2] = ~rcode
; msk
[3] = 0x01; break;
520 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01; msk
[2] = ~rcode
; msk
[3] = 0x03; break;
521 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C; msk
[2] = ~rcode
; msk
[3] = 0x0f; break;
522 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F; msk
[2] = ~rcode
; msk
[3] = 0xff; break;
523 default: return -EINVAL
;
526 bbtoffs
= chip
* (numblocks
>> 2);
528 to
= ((loff_t
) page
) << this->page_shift
;
530 memcpy (&oobinfo
, this->autooob
, sizeof(oobinfo
));
531 oobinfo
.useecc
= MTD_NANDECC_PLACEONLY
;
533 /* Must we save the block contents ? */
534 if (td
->options
& NAND_BBT_SAVECONTENT
) {
535 /* Make it block aligned */
536 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
537 len
= 1 << this->bbt_erase_shift
;
538 res
= mtd
->read_ecc (mtd
, to
, len
, &retlen
, buf
, &buf
[len
], &oobinfo
);
541 printk (KERN_INFO
"nand_bbt: Error reading block for writing the bad block table\n");
544 printk (KERN_WARNING
"nand_bbt: ECC error while reading block for writing bad block table\n");
546 /* Calc the byte offset in the buffer */
547 pageoffs
= page
- (int)(to
>> this->page_shift
);
548 offs
= pageoffs
<< this->page_shift
;
549 /* Preset the bbt area with 0xff */
550 memset (&buf
[offs
], 0xff, (size_t)(numblocks
>> sft
));
551 /* Preset the bbt's oob area with 0xff */
552 memset (&buf
[len
+ pageoffs
* mtd
->oobsize
], 0xff,
553 ((len
>> this->page_shift
) - pageoffs
) * mtd
->oobsize
);
554 if (td
->options
& NAND_BBT_VERSION
) {
555 buf
[len
+ (pageoffs
* mtd
->oobsize
) + td
->veroffs
] = td
->version
[chip
];
559 len
= (size_t) (numblocks
>> sft
);
560 /* Make it page aligned ! */
561 len
= (len
+ (mtd
->oobblock
-1)) & ~(mtd
->oobblock
-1);
562 /* Preset the buffer with 0xff */
563 memset (buf
, 0xff, len
+ (len
>> this->page_shift
) * mtd
->oobsize
);
565 /* Pattern is located in oob area of first page */
566 memcpy (&buf
[len
+ td
->offs
], td
->pattern
, td
->len
);
567 if (td
->options
& NAND_BBT_VERSION
) {
568 buf
[len
+ td
->veroffs
] = td
->version
[chip
];
572 /* walk through the memory table */
573 for (i
= 0; i
< numblocks
; ) {
575 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
576 for (j
= 0; j
< 4; j
++ , i
++) {
577 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
578 /* Do not store the reserved bbt blocks ! */
579 buf
[offs
+ (i
>> sft
)] &= ~(msk
[dat
& 0x03] << sftcnt
);
584 memset (&einfo
, 0, sizeof (einfo
));
586 einfo
.addr
= (unsigned long) to
;
587 einfo
.len
= 1 << this->bbt_erase_shift
;
588 res
= nand_erase_nand (mtd
, &einfo
, 1);
590 printk (KERN_WARNING
"nand_bbt: Error during block erase: %d\n", res
);
594 res
= mtd
->write_ecc (mtd
, to
, len
, &retlen
, buf
, &buf
[len
], &oobinfo
);
596 printk (KERN_WARNING
"nand_bbt: Error while writing bad block table %d\n", res
);
599 printk (KERN_DEBUG
"Bad block table written to 0x%08x, version 0x%02X\n",
600 (unsigned int) to
, td
->version
[chip
]);
602 /* Mark it as used */
603 td
->pages
[chip
] = page
;
609 * nand_memory_bbt - [GENERIC] create a memory based bad block table
610 * @mtd: MTD device structure
611 * @bd: descriptor for the good/bad block search pattern
613 * The function creates a memory based bbt by scanning the device
614 * for manufacturer / software marked good / bad blocks
616 static inline int nand_memory_bbt (struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
618 struct nand_chip
*this = mtd
->priv
;
620 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
621 return create_bbt (mtd
, this->data_buf
, bd
, -1);
625 * check_create - [GENERIC] create and write bbt(s) if neccecary
626 * @mtd: MTD device structure
627 * @buf: temporary buffer
628 * @bd: descriptor for the good/bad block search pattern
630 * The function checks the results of the previous call to read_bbt
631 * and creates / updates the bbt(s) if neccecary
632 * Creation is neccecary if no bbt was found for the chip/device
633 * Update is neccecary if one of the tables is missing or the
634 * version nr. of one table is less than the other
636 static int check_create (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
638 int i
, chips
, writeops
, chipsel
, res
;
639 struct nand_chip
*this = mtd
->priv
;
640 struct nand_bbt_descr
*td
= this->bbt_td
;
641 struct nand_bbt_descr
*md
= this->bbt_md
;
642 struct nand_bbt_descr
*rd
, *rd2
;
644 /* Do we have a bbt per chip ? */
645 if (td
->options
& NAND_BBT_PERCHIP
)
646 chips
= this->numchips
;
650 for (i
= 0; i
< chips
; i
++) {
654 /* Per chip or per device ? */
655 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
656 /* Mirrored table avilable ? */
658 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
663 if (td
->pages
[i
] == -1) {
665 td
->version
[i
] = md
->version
[i
];
670 if (md
->pages
[i
] == -1) {
672 md
->version
[i
] = td
->version
[i
];
677 if (td
->version
[i
] == md
->version
[i
]) {
679 if (!(td
->options
& NAND_BBT_VERSION
))
684 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
686 md
->version
[i
] = td
->version
[i
];
690 td
->version
[i
] = md
->version
[i
];
697 if (td
->pages
[i
] == -1) {
705 /* Create the bad block table by scanning the device ? */
706 if (!(td
->options
& NAND_BBT_CREATE
))
709 /* Create the table in memory by scanning the chip(s) */
710 create_bbt (mtd
, buf
, bd
, chipsel
);
716 /* read back first ? */
718 read_abs_bbt (mtd
, buf
, rd
, chipsel
);
719 /* If they weren't versioned, read both. */
721 read_abs_bbt (mtd
, buf
, rd2
, chipsel
);
723 /* Write the bad block table to the device ? */
724 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
725 res
= write_bbt (mtd
, buf
, td
, md
, chipsel
);
730 /* Write the mirror bad block table to the device ? */
731 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
732 res
= write_bbt (mtd
, buf
, md
, td
, chipsel
);
741 * mark_bbt_regions - [GENERIC] mark the bad block table regions
742 * @mtd: MTD device structure
743 * @td: bad block table descriptor
745 * The bad block table regions are marked as "bad" to prevent
746 * accidental erasures / writes. The regions are identified by
749 static void mark_bbt_region (struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
751 struct nand_chip
*this = mtd
->priv
;
752 int i
, j
, chips
, block
, nrblocks
, update
;
753 uint8_t oldval
, newval
;
755 /* Do we have a bbt per chip ? */
756 if (td
->options
& NAND_BBT_PERCHIP
) {
757 chips
= this->numchips
;
758 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
761 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
764 for (i
= 0; i
< chips
; i
++) {
765 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
766 !(td
->options
& NAND_BBT_WRITE
)) {
767 if (td
->pages
[i
] == -1) continue;
768 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
770 oldval
= this->bbt
[(block
>> 3)];
771 newval
= oldval
| (0x2 << (block
& 0x06));
772 this->bbt
[(block
>> 3)] = newval
;
773 if ((oldval
!= newval
) && td
->reserved_block_code
)
774 nand_update_bbt(mtd
, block
<< (this->bbt_erase_shift
- 1));
778 if (td
->options
& NAND_BBT_LASTBLOCK
)
779 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
781 block
= i
* nrblocks
;
783 for (j
= 0; j
< td
->maxblocks
; j
++) {
784 oldval
= this->bbt
[(block
>> 3)];
785 newval
= oldval
| (0x2 << (block
& 0x06));
786 this->bbt
[(block
>> 3)] = newval
;
787 if (oldval
!= newval
) update
= 1;
790 /* If we want reserved blocks to be recorded to flash, and some
791 new ones have been marked, then we need to update the stored
792 bbts. This should only happen once. */
793 if (update
&& td
->reserved_block_code
)
794 nand_update_bbt(mtd
, (block
- 2) << (this->bbt_erase_shift
- 1));
799 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
800 * @mtd: MTD device structure
801 * @bd: descriptor for the good/bad block search pattern
803 * The function checks, if a bad block table(s) is/are already
804 * available. If not it scans the device for manufacturer
805 * marked good / bad blocks and writes the bad block table(s) to
806 * the selected place.
808 * The bad block table memory is allocated here. It must be freed
809 * by calling the nand_free_bbt function.
812 int nand_scan_bbt (struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
814 struct nand_chip
*this = mtd
->priv
;
817 struct nand_bbt_descr
*td
= this->bbt_td
;
818 struct nand_bbt_descr
*md
= this->bbt_md
;
820 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
821 /* Allocate memory (2bit per block) */
822 this->bbt
= kmalloc (len
, GFP_KERNEL
);
824 printk (KERN_ERR
"nand_scan_bbt: Out of memory\n");
827 /* Clear the memory bad block table */
828 memset (this->bbt
, 0x00, len
);
830 /* If no primary table decriptor is given, scan the device
831 * to build a memory based bad block table
834 if ((res
= nand_memory_bbt(mtd
, bd
))) {
835 printk (KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
842 /* Allocate a temporary buffer for one eraseblock incl. oob */
843 len
= (1 << this->bbt_erase_shift
);
844 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
845 buf
= kmalloc (len
, GFP_KERNEL
);
847 printk (KERN_ERR
"nand_bbt: Out of memory\n");
853 /* Is the bbt at a given page ? */
854 if (td
->options
& NAND_BBT_ABSPAGE
) {
855 res
= read_abs_bbts (mtd
, buf
, td
, md
);
857 /* Search the bad block table using a pattern in oob */
858 res
= search_read_bbts (mtd
, buf
, td
, md
);
862 res
= check_create (mtd
, buf
, bd
);
864 /* Prevent the bbt regions from erasing / writing */
865 mark_bbt_region (mtd
, td
);
867 mark_bbt_region (mtd
, md
);
875 * nand_update_bbt - [NAND Interface] update bad block table(s)
876 * @mtd: MTD device structure
877 * @offs: the offset of the newly marked block
879 * The function updates the bad block table(s)
881 int nand_update_bbt (struct mtd_info
*mtd
, loff_t offs
)
883 struct nand_chip
*this = mtd
->priv
;
884 int len
, res
= 0, writeops
= 0;
887 struct nand_bbt_descr
*td
= this->bbt_td
;
888 struct nand_bbt_descr
*md
= this->bbt_md
;
890 if (!this->bbt
|| !td
)
893 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
894 /* Allocate a temporary buffer for one eraseblock incl. oob */
895 len
= (1 << this->bbt_erase_shift
);
896 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
897 buf
= kmalloc (len
, GFP_KERNEL
);
899 printk (KERN_ERR
"nand_update_bbt: Out of memory\n");
903 writeops
= md
!= NULL
? 0x03 : 0x01;
905 /* Do we have a bbt per chip ? */
906 if (td
->options
& NAND_BBT_PERCHIP
) {
907 chip
= (int) (offs
>> this->chip_shift
);
918 /* Write the bad block table to the device ? */
919 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
920 res
= write_bbt (mtd
, buf
, td
, md
, chipsel
);
924 /* Write the mirror bad block table to the device ? */
925 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
926 res
= write_bbt (mtd
, buf
, md
, td
, chipsel
);
934 /* Define some generic bad / good block scan pattern which are used
935 * while scanning a device for factory marked good / bad blocks. */
936 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
938 static struct nand_bbt_descr smallpage_memorybased
= {
939 .options
= NAND_BBT_SCAN2NDPAGE
,
942 .pattern
= scan_ff_pattern
945 static struct nand_bbt_descr largepage_memorybased
= {
949 .pattern
= scan_ff_pattern
952 static struct nand_bbt_descr smallpage_flashbased
= {
953 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
956 .pattern
= scan_ff_pattern
959 static struct nand_bbt_descr largepage_flashbased
= {
960 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
963 .pattern
= scan_ff_pattern
966 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
968 static struct nand_bbt_descr agand_flashbased
= {
969 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
972 .pattern
= scan_agand_pattern
975 /* Generic flash bbt decriptors
977 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
978 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
980 static struct nand_bbt_descr bbt_main_descr
= {
981 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
982 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
987 .pattern
= bbt_pattern
990 static struct nand_bbt_descr bbt_mirror_descr
= {
991 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
992 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
997 .pattern
= mirror_pattern
1001 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1002 * @mtd: MTD device structure
1004 * This function selects the default bad block table
1005 * support for the device and calls the nand_scan_bbt function
1008 int nand_default_bbt (struct mtd_info
*mtd
)
1010 struct nand_chip
*this = mtd
->priv
;
1012 /* Default for AG-AND. We must use a flash based
1013 * bad block table as the devices have factory marked
1014 * _good_ blocks. Erasing those blocks leads to loss
1015 * of the good / bad information, so we _must_ store
1016 * this information in a good / bad table during
1019 if (this->options
& NAND_IS_AND
) {
1020 /* Use the default pattern descriptors */
1021 if (!this->bbt_td
) {
1022 this->bbt_td
= &bbt_main_descr
;
1023 this->bbt_md
= &bbt_mirror_descr
;
1025 this->options
|= NAND_USE_FLASH_BBT
;
1026 return nand_scan_bbt (mtd
, &agand_flashbased
);
1030 /* Is a flash based bad block table requested ? */
1031 if (this->options
& NAND_USE_FLASH_BBT
) {
1032 /* Use the default pattern descriptors */
1033 if (!this->bbt_td
) {
1034 this->bbt_td
= &bbt_main_descr
;
1035 this->bbt_md
= &bbt_mirror_descr
;
1037 if (!this->badblock_pattern
) {
1038 this->badblock_pattern
= (mtd
->oobblock
> 512) ?
1039 &largepage_flashbased
: &smallpage_flashbased
;
1042 this->bbt_td
= NULL
;
1043 this->bbt_md
= NULL
;
1044 if (!this->badblock_pattern
) {
1045 this->badblock_pattern
= (mtd
->oobblock
> 512) ?
1046 &largepage_memorybased
: &smallpage_memorybased
;
1049 return nand_scan_bbt (mtd
, this->badblock_pattern
);
1053 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1054 * @mtd: MTD device structure
1055 * @offs: offset in the device
1056 * @allowbbt: allow access to bad block table region
1059 int nand_isbad_bbt (struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1061 struct nand_chip
*this = mtd
->priv
;
1065 /* Get block number * 2 */
1066 block
= (int) (offs
>> (this->bbt_erase_shift
- 1));
1067 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1069 DEBUG (MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1070 (unsigned int)offs
, block
>> 1, res
);
1073 case 0x00: return 0;
1074 case 0x01: return 1;
1075 case 0x02: return allowbbt
? 0 : 1;
1080 EXPORT_SYMBOL (nand_scan_bbt
);
1081 EXPORT_SYMBOL (nand_default_bbt
);