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 1.33 2005/06/14 15:47:56 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24 * If one of the bbt's is out of date or does not exist it is (re)created.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 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 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 * @len: the length of buffer to search
113 * @paglen: the pagelength
114 * @td: search pattern descriptor
116 * Check for a pattern at the given place. Used to search bad block
117 * tables and good / bad block identifiers. Same as check_pattern, but
118 * no optional empty check and the pattern is expected to start
122 static int check_short_pattern (uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
127 /* Compare the pattern */
128 for (i
= 0; i
< td
->len
; i
++) {
129 if (p
[i
] != td
->pattern
[i
])
136 * read_bbt - [GENERIC] Read the bad block table starting from page
137 * @mtd: MTD device structure
138 * @buf: temporary buffer
139 * @page: the starting page
140 * @num: the number of bbt descriptors to read
141 * @bits: number of bits per block
142 * @offs: offset in the memory table
143 * @reserved_block_code: Pattern to identify reserved blocks
145 * Read the bad block table starting from page.
148 static int read_bbt (struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
149 int bits
, int offs
, int reserved_block_code
)
151 int res
, i
, j
, act
= 0;
152 struct nand_chip
*this = mtd
->priv
;
153 size_t retlen
, len
, totlen
;
155 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
157 totlen
= (num
* bits
) >> 3;
158 from
= ((loff_t
)page
) << this->page_shift
;
161 len
= min (totlen
, (size_t) (1 << this->bbt_erase_shift
));
162 res
= mtd
->read_ecc (mtd
, from
, len
, &retlen
, buf
, NULL
, this->autooob
);
165 printk (KERN_INFO
"nand_bbt: Error reading bad block table\n");
168 printk (KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
172 for (i
= 0; i
< len
; i
++) {
173 uint8_t dat
= buf
[i
];
174 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
175 uint8_t tmp
= (dat
>> j
) & msk
;
178 if (reserved_block_code
&&
179 (tmp
== reserved_block_code
)) {
180 printk (KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%08x\n",
181 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
182 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
185 /* Leave it for now, if its matured we can move this
186 * message to MTD_DEBUG_LEVEL0 */
187 printk (KERN_DEBUG
"nand_read_bbt: Bad block at 0x%08x\n",
188 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
189 /* Factory marked bad or worn out ? */
191 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
193 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
203 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
204 * @mtd: MTD device structure
205 * @buf: temporary buffer
206 * @td: descriptor for the bad block table
207 * @chip: read the table for a specific chip, -1 read all chips.
208 * Applies only if NAND_BBT_PERCHIP option is set
210 * Read the bad block table for all chips starting at a given page
211 * We assume that the bbt bits are in consecutive order.
213 static int read_abs_bbt (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
215 struct nand_chip
*this = mtd
->priv
;
219 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
220 if (td
->options
& NAND_BBT_PERCHIP
) {
222 for (i
= 0; i
< this->numchips
; i
++) {
223 if (chip
== -1 || chip
== i
)
224 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
227 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
230 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
238 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
239 * @mtd: MTD device structure
240 * @buf: temporary buffer
241 * @td: descriptor for the bad block table
242 * @md: descriptor for the bad block table mirror
244 * Read the bad block table(s) for all chips starting at a given page
245 * We assume that the bbt bits are in consecutive order.
248 static int read_abs_bbts (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
,
249 struct nand_bbt_descr
*md
)
251 struct nand_chip
*this = mtd
->priv
;
253 /* Read the primary version, if available */
254 if (td
->options
& NAND_BBT_VERSION
) {
255 nand_read_raw (mtd
, buf
, td
->pages
[0] << this->page_shift
, mtd
->oobblock
, mtd
->oobsize
);
256 td
->version
[0] = buf
[mtd
->oobblock
+ td
->veroffs
];
257 printk (KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n", td
->pages
[0], td
->version
[0]);
260 /* Read the mirror version, if available */
261 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
262 nand_read_raw (mtd
, buf
, md
->pages
[0] << this->page_shift
, mtd
->oobblock
, mtd
->oobsize
);
263 md
->version
[0] = buf
[mtd
->oobblock
+ md
->veroffs
];
264 printk (KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n", md
->pages
[0], md
->version
[0]);
271 * create_bbt - [GENERIC] Create a bad block table by scanning the device
272 * @mtd: MTD device structure
273 * @buf: temporary buffer
274 * @bd: descriptor for the good/bad block search pattern
275 * @chip: create the table for a specific chip, -1 read all chips.
276 * Applies only if NAND_BBT_PERCHIP option is set
278 * Create a bad block table by scanning the device
279 * for the given good/bad block identify pattern
281 static int create_bbt (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
, int chip
)
283 struct nand_chip
*this = mtd
->priv
;
284 int i
, j
, numblocks
, len
, scanlen
;
287 size_t readlen
, ooblen
;
289 printk (KERN_INFO
"Scanning device for bad blocks\n");
291 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
292 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
294 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
300 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
301 /* We need only read few bytes from the OOB area */
302 scanlen
= ooblen
= 0;
305 /* Full page content should be read */
306 scanlen
= mtd
->oobblock
+ mtd
->oobsize
;
307 readlen
= len
* mtd
->oobblock
;
308 ooblen
= len
* mtd
->oobsize
;
312 /* Note that numblocks is 2 * (real numblocks) here, see i+=2 below as it
313 * makes shifting and masking less painful */
314 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
318 if (chip
>= this->numchips
) {
319 printk (KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
320 chip
+ 1, this->numchips
);
323 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
324 startblock
= chip
* numblocks
;
325 numblocks
+= startblock
;
326 from
= startblock
<< (this->bbt_erase_shift
- 1);
329 for (i
= startblock
; i
< numblocks
;) {
332 if (bd
->options
& NAND_BBT_SCANEMPTY
)
333 if ((ret
= nand_read_raw (mtd
, buf
, from
, readlen
, ooblen
)))
336 for (j
= 0; j
< len
; j
++) {
337 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
340 /* No need to read pages fully, just read required OOB bytes */
341 ret
= mtd
->read_oob(mtd
, from
+ j
* mtd
->oobblock
+ bd
->offs
,
342 readlen
, &retlen
, &buf
[0]);
346 if (check_short_pattern (&buf
[j
* scanlen
], scanlen
, mtd
->oobblock
, bd
)) {
347 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
348 printk (KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
349 i
>> 1, (unsigned int) from
);
353 if (check_pattern (&buf
[j
* scanlen
], scanlen
, mtd
->oobblock
, bd
)) {
354 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
355 printk (KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
356 i
>> 1, (unsigned int) from
);
362 from
+= (1 << this->bbt_erase_shift
);
368 * search_bbt - [GENERIC] scan the device for a specific bad block table
369 * @mtd: MTD device structure
370 * @buf: temporary buffer
371 * @td: descriptor for the bad block table
373 * Read the bad block table by searching for a given ident pattern.
374 * Search is preformed either from the beginning up or from the end of
375 * the device downwards. The search starts always at the start of a
377 * If the option NAND_BBT_PERCHIP is given, each chip is searched
378 * for a bbt, which contains the bad block information of this chip.
379 * This is neccecary to provide support for certain DOC devices.
381 * The bbt ident pattern resides in the oob area of the first page
384 static int search_bbt (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
386 struct nand_chip
*this = mtd
->priv
;
388 int bits
, startblock
, block
, dir
;
389 int scanlen
= mtd
->oobblock
+ mtd
->oobsize
;
392 /* Search direction top -> down ? */
393 if (td
->options
& NAND_BBT_LASTBLOCK
) {
394 startblock
= (mtd
->size
>> this->bbt_erase_shift
) -1;
401 /* Do we have a bbt per chip ? */
402 if (td
->options
& NAND_BBT_PERCHIP
) {
403 chips
= this->numchips
;
404 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
405 startblock
&= bbtblocks
- 1;
408 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
411 /* Number of bits for each erase block in the bbt */
412 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
414 for (i
= 0; i
< chips
; i
++) {
415 /* Reset version information */
418 /* Scan the maximum number of blocks */
419 for (block
= 0; block
< td
->maxblocks
; block
++) {
420 int actblock
= startblock
+ dir
* block
;
421 /* Read first page */
422 nand_read_raw (mtd
, buf
, actblock
<< this->bbt_erase_shift
, mtd
->oobblock
, mtd
->oobsize
);
423 if (!check_pattern(buf
, scanlen
, mtd
->oobblock
, td
)) {
424 td
->pages
[i
] = actblock
<< (this->bbt_erase_shift
- this->page_shift
);
425 if (td
->options
& NAND_BBT_VERSION
) {
426 td
->version
[i
] = buf
[mtd
->oobblock
+ td
->veroffs
];
431 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
433 /* Check, if we found a bbt for each requested chip */
434 for (i
= 0; i
< chips
; i
++) {
435 if (td
->pages
[i
] == -1)
436 printk (KERN_WARNING
"Bad block table not found for chip %d\n", i
);
438 printk (KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
], td
->version
[i
]);
444 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
445 * @mtd: MTD device structure
446 * @buf: temporary buffer
447 * @td: descriptor for the bad block table
448 * @md: descriptor for the bad block table mirror
450 * Search and read the bad block table(s)
452 static int search_read_bbts (struct mtd_info
*mtd
, uint8_t *buf
,
453 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
455 /* Search the primary table */
456 search_bbt (mtd
, buf
, td
);
458 /* Search the mirror table */
460 search_bbt (mtd
, buf
, md
);
462 /* Force result check */
468 * write_bbt - [GENERIC] (Re)write the bad block table
470 * @mtd: MTD device structure
471 * @buf: temporary buffer
472 * @td: descriptor for the bad block table
473 * @md: descriptor for the bad block table mirror
474 * @chipsel: selector for a specific chip, -1 for all
476 * (Re)write the bad block table
479 static int write_bbt (struct mtd_info
*mtd
, uint8_t *buf
,
480 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
, int chipsel
)
482 struct nand_chip
*this = mtd
->priv
;
483 struct nand_oobinfo oobinfo
;
484 struct erase_info einfo
;
485 int i
, j
, res
, chip
= 0;
486 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
487 int nrchips
, bbtoffs
, pageoffs
;
489 uint8_t rcode
= td
->reserved_block_code
;
490 size_t retlen
, len
= 0;
495 /* Write bad block table per chip rather than per device ? */
496 if (td
->options
& NAND_BBT_PERCHIP
) {
497 numblocks
= (int) (this->chipsize
>> this->bbt_erase_shift
);
498 /* Full device write or specific chip ? */
500 nrchips
= this->numchips
;
502 nrchips
= chipsel
+ 1;
506 numblocks
= (int) (mtd
->size
>> this->bbt_erase_shift
);
510 /* Loop through the chips */
511 for (; chip
< nrchips
; chip
++) {
513 /* There was already a version of the table, reuse the page
514 * This applies for absolute placement too, as we have the
515 * page nr. in td->pages.
517 if (td
->pages
[chip
] != -1) {
518 page
= td
->pages
[chip
];
522 /* Automatic placement of the bad block table */
523 /* Search direction top -> down ? */
524 if (td
->options
& NAND_BBT_LASTBLOCK
) {
525 startblock
= numblocks
* (chip
+ 1) - 1;
528 startblock
= chip
* numblocks
;
532 for (i
= 0; i
< td
->maxblocks
; i
++) {
533 int block
= startblock
+ dir
* i
;
534 /* Check, if the block is bad */
535 switch ((this->bbt
[block
>> 2] >> (2 * (block
& 0x03))) & 0x03) {
540 page
= block
<< (this->bbt_erase_shift
- this->page_shift
);
541 /* Check, if the block is used by the mirror table */
542 if (!md
|| md
->pages
[chip
] != page
)
545 printk (KERN_ERR
"No space left to write bad block table\n");
549 /* Set up shift count and masks for the flash table */
550 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
552 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01; msk
[2] = ~rcode
; msk
[3] = 0x01; break;
553 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01; msk
[2] = ~rcode
; msk
[3] = 0x03; break;
554 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C; msk
[2] = ~rcode
; msk
[3] = 0x0f; break;
555 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F; msk
[2] = ~rcode
; msk
[3] = 0xff; break;
556 default: return -EINVAL
;
559 bbtoffs
= chip
* (numblocks
>> 2);
561 to
= ((loff_t
) page
) << this->page_shift
;
563 memcpy (&oobinfo
, this->autooob
, sizeof(oobinfo
));
564 oobinfo
.useecc
= MTD_NANDECC_PLACEONLY
;
566 /* Must we save the block contents ? */
567 if (td
->options
& NAND_BBT_SAVECONTENT
) {
568 /* Make it block aligned */
569 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
570 len
= 1 << this->bbt_erase_shift
;
571 res
= mtd
->read_ecc (mtd
, to
, len
, &retlen
, buf
, &buf
[len
], &oobinfo
);
574 printk (KERN_INFO
"nand_bbt: Error reading block for writing the bad block table\n");
577 printk (KERN_WARNING
"nand_bbt: ECC error while reading block for writing bad block table\n");
579 /* Calc the byte offset in the buffer */
580 pageoffs
= page
- (int)(to
>> this->page_shift
);
581 offs
= pageoffs
<< this->page_shift
;
582 /* Preset the bbt area with 0xff */
583 memset (&buf
[offs
], 0xff, (size_t)(numblocks
>> sft
));
584 /* Preset the bbt's oob area with 0xff */
585 memset (&buf
[len
+ pageoffs
* mtd
->oobsize
], 0xff,
586 ((len
>> this->page_shift
) - pageoffs
) * mtd
->oobsize
);
587 if (td
->options
& NAND_BBT_VERSION
) {
588 buf
[len
+ (pageoffs
* mtd
->oobsize
) + td
->veroffs
] = td
->version
[chip
];
592 len
= (size_t) (numblocks
>> sft
);
593 /* Make it page aligned ! */
594 len
= (len
+ (mtd
->oobblock
-1)) & ~(mtd
->oobblock
-1);
595 /* Preset the buffer with 0xff */
596 memset (buf
, 0xff, len
+ (len
>> this->page_shift
) * mtd
->oobsize
);
598 /* Pattern is located in oob area of first page */
599 memcpy (&buf
[len
+ td
->offs
], td
->pattern
, td
->len
);
600 if (td
->options
& NAND_BBT_VERSION
) {
601 buf
[len
+ td
->veroffs
] = td
->version
[chip
];
605 /* walk through the memory table */
606 for (i
= 0; i
< numblocks
; ) {
608 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
609 for (j
= 0; j
< 4; j
++ , i
++) {
610 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
611 /* Do not store the reserved bbt blocks ! */
612 buf
[offs
+ (i
>> sft
)] &= ~(msk
[dat
& 0x03] << sftcnt
);
617 memset (&einfo
, 0, sizeof (einfo
));
619 einfo
.addr
= (unsigned long) to
;
620 einfo
.len
= 1 << this->bbt_erase_shift
;
621 res
= nand_erase_nand (mtd
, &einfo
, 1);
623 printk (KERN_WARNING
"nand_bbt: Error during block erase: %d\n", res
);
627 res
= mtd
->write_ecc (mtd
, to
, len
, &retlen
, buf
, &buf
[len
], &oobinfo
);
629 printk (KERN_WARNING
"nand_bbt: Error while writing bad block table %d\n", res
);
632 printk (KERN_DEBUG
"Bad block table written to 0x%08x, version 0x%02X\n",
633 (unsigned int) to
, td
->version
[chip
]);
635 /* Mark it as used */
636 td
->pages
[chip
] = page
;
642 * nand_memory_bbt - [GENERIC] create a memory based bad block table
643 * @mtd: MTD device structure
644 * @bd: descriptor for the good/bad block search pattern
646 * The function creates a memory based bbt by scanning the device
647 * for manufacturer / software marked good / bad blocks
649 static inline int nand_memory_bbt (struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
651 struct nand_chip
*this = mtd
->priv
;
653 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
654 return create_bbt (mtd
, this->data_buf
, bd
, -1);
658 * check_create - [GENERIC] create and write bbt(s) if neccecary
659 * @mtd: MTD device structure
660 * @buf: temporary buffer
661 * @bd: descriptor for the good/bad block search pattern
663 * The function checks the results of the previous call to read_bbt
664 * and creates / updates the bbt(s) if neccecary
665 * Creation is neccecary if no bbt was found for the chip/device
666 * Update is neccecary if one of the tables is missing or the
667 * version nr. of one table is less than the other
669 static int check_create (struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
671 int i
, chips
, writeops
, chipsel
, res
;
672 struct nand_chip
*this = mtd
->priv
;
673 struct nand_bbt_descr
*td
= this->bbt_td
;
674 struct nand_bbt_descr
*md
= this->bbt_md
;
675 struct nand_bbt_descr
*rd
, *rd2
;
677 /* Do we have a bbt per chip ? */
678 if (td
->options
& NAND_BBT_PERCHIP
)
679 chips
= this->numchips
;
683 for (i
= 0; i
< chips
; i
++) {
687 /* Per chip or per device ? */
688 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
689 /* Mirrored table avilable ? */
691 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
696 if (td
->pages
[i
] == -1) {
698 td
->version
[i
] = md
->version
[i
];
703 if (md
->pages
[i
] == -1) {
705 md
->version
[i
] = td
->version
[i
];
710 if (td
->version
[i
] == md
->version
[i
]) {
712 if (!(td
->options
& NAND_BBT_VERSION
))
717 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
719 md
->version
[i
] = td
->version
[i
];
723 td
->version
[i
] = md
->version
[i
];
730 if (td
->pages
[i
] == -1) {
738 /* Create the bad block table by scanning the device ? */
739 if (!(td
->options
& NAND_BBT_CREATE
))
742 /* Create the table in memory by scanning the chip(s) */
743 create_bbt (mtd
, buf
, bd
, chipsel
);
749 /* read back first ? */
751 read_abs_bbt (mtd
, buf
, rd
, chipsel
);
752 /* If they weren't versioned, read both. */
754 read_abs_bbt (mtd
, buf
, rd2
, chipsel
);
756 /* Write the bad block table to the device ? */
757 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
758 res
= write_bbt (mtd
, buf
, td
, md
, chipsel
);
763 /* Write the mirror bad block table to the device ? */
764 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
765 res
= write_bbt (mtd
, buf
, md
, td
, chipsel
);
774 * mark_bbt_regions - [GENERIC] mark the bad block table regions
775 * @mtd: MTD device structure
776 * @td: bad block table descriptor
778 * The bad block table regions are marked as "bad" to prevent
779 * accidental erasures / writes. The regions are identified by
782 static void mark_bbt_region (struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
784 struct nand_chip
*this = mtd
->priv
;
785 int i
, j
, chips
, block
, nrblocks
, update
;
786 uint8_t oldval
, newval
;
788 /* Do we have a bbt per chip ? */
789 if (td
->options
& NAND_BBT_PERCHIP
) {
790 chips
= this->numchips
;
791 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
794 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
797 for (i
= 0; i
< chips
; i
++) {
798 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
799 !(td
->options
& NAND_BBT_WRITE
)) {
800 if (td
->pages
[i
] == -1) continue;
801 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
803 oldval
= this->bbt
[(block
>> 3)];
804 newval
= oldval
| (0x2 << (block
& 0x06));
805 this->bbt
[(block
>> 3)] = newval
;
806 if ((oldval
!= newval
) && td
->reserved_block_code
)
807 nand_update_bbt(mtd
, block
<< (this->bbt_erase_shift
- 1));
811 if (td
->options
& NAND_BBT_LASTBLOCK
)
812 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
814 block
= i
* nrblocks
;
816 for (j
= 0; j
< td
->maxblocks
; j
++) {
817 oldval
= this->bbt
[(block
>> 3)];
818 newval
= oldval
| (0x2 << (block
& 0x06));
819 this->bbt
[(block
>> 3)] = newval
;
820 if (oldval
!= newval
) update
= 1;
823 /* If we want reserved blocks to be recorded to flash, and some
824 new ones have been marked, then we need to update the stored
825 bbts. This should only happen once. */
826 if (update
&& td
->reserved_block_code
)
827 nand_update_bbt(mtd
, (block
- 2) << (this->bbt_erase_shift
- 1));
832 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
833 * @mtd: MTD device structure
834 * @bd: descriptor for the good/bad block search pattern
836 * The function checks, if a bad block table(s) is/are already
837 * available. If not it scans the device for manufacturer
838 * marked good / bad blocks and writes the bad block table(s) to
839 * the selected place.
841 * The bad block table memory is allocated here. It must be freed
842 * by calling the nand_free_bbt function.
845 int nand_scan_bbt (struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
847 struct nand_chip
*this = mtd
->priv
;
850 struct nand_bbt_descr
*td
= this->bbt_td
;
851 struct nand_bbt_descr
*md
= this->bbt_md
;
853 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
854 /* Allocate memory (2bit per block) */
855 this->bbt
= kmalloc (len
, GFP_KERNEL
);
857 printk (KERN_ERR
"nand_scan_bbt: Out of memory\n");
860 /* Clear the memory bad block table */
861 memset (this->bbt
, 0x00, len
);
863 /* If no primary table decriptor is given, scan the device
864 * to build a memory based bad block table
867 if ((res
= nand_memory_bbt(mtd
, bd
))) {
868 printk (KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
875 /* Allocate a temporary buffer for one eraseblock incl. oob */
876 len
= (1 << this->bbt_erase_shift
);
877 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
878 buf
= kmalloc (len
, GFP_KERNEL
);
880 printk (KERN_ERR
"nand_bbt: Out of memory\n");
886 /* Is the bbt at a given page ? */
887 if (td
->options
& NAND_BBT_ABSPAGE
) {
888 res
= read_abs_bbts (mtd
, buf
, td
, md
);
890 /* Search the bad block table using a pattern in oob */
891 res
= search_read_bbts (mtd
, buf
, td
, md
);
895 res
= check_create (mtd
, buf
, bd
);
897 /* Prevent the bbt regions from erasing / writing */
898 mark_bbt_region (mtd
, td
);
900 mark_bbt_region (mtd
, md
);
908 * nand_update_bbt - [NAND Interface] update bad block table(s)
909 * @mtd: MTD device structure
910 * @offs: the offset of the newly marked block
912 * The function updates the bad block table(s)
914 int nand_update_bbt (struct mtd_info
*mtd
, loff_t offs
)
916 struct nand_chip
*this = mtd
->priv
;
917 int len
, res
= 0, writeops
= 0;
920 struct nand_bbt_descr
*td
= this->bbt_td
;
921 struct nand_bbt_descr
*md
= this->bbt_md
;
923 if (!this->bbt
|| !td
)
926 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
927 /* Allocate a temporary buffer for one eraseblock incl. oob */
928 len
= (1 << this->bbt_erase_shift
);
929 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
930 buf
= kmalloc (len
, GFP_KERNEL
);
932 printk (KERN_ERR
"nand_update_bbt: Out of memory\n");
936 writeops
= md
!= NULL
? 0x03 : 0x01;
938 /* Do we have a bbt per chip ? */
939 if (td
->options
& NAND_BBT_PERCHIP
) {
940 chip
= (int) (offs
>> this->chip_shift
);
951 /* Write the bad block table to the device ? */
952 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
953 res
= write_bbt (mtd
, buf
, td
, md
, chipsel
);
957 /* Write the mirror bad block table to the device ? */
958 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
959 res
= write_bbt (mtd
, buf
, md
, td
, chipsel
);
967 /* Define some generic bad / good block scan pattern which are used
968 * while scanning a device for factory marked good / bad blocks. */
969 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
971 static struct nand_bbt_descr smallpage_memorybased
= {
972 .options
= NAND_BBT_SCAN2NDPAGE
,
975 .pattern
= scan_ff_pattern
978 static struct nand_bbt_descr largepage_memorybased
= {
982 .pattern
= scan_ff_pattern
985 static struct nand_bbt_descr smallpage_flashbased
= {
986 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
989 .pattern
= scan_ff_pattern
992 static struct nand_bbt_descr largepage_flashbased
= {
993 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
996 .pattern
= scan_ff_pattern
999 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1001 static struct nand_bbt_descr agand_flashbased
= {
1002 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1005 .pattern
= scan_agand_pattern
1008 /* Generic flash bbt decriptors
1010 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1011 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1013 static struct nand_bbt_descr bbt_main_descr
= {
1014 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1015 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1020 .pattern
= bbt_pattern
1023 static struct nand_bbt_descr bbt_mirror_descr
= {
1024 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1025 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1030 .pattern
= mirror_pattern
1034 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1035 * @mtd: MTD device structure
1037 * This function selects the default bad block table
1038 * support for the device and calls the nand_scan_bbt function
1041 int nand_default_bbt (struct mtd_info
*mtd
)
1043 struct nand_chip
*this = mtd
->priv
;
1045 /* Default for AG-AND. We must use a flash based
1046 * bad block table as the devices have factory marked
1047 * _good_ blocks. Erasing those blocks leads to loss
1048 * of the good / bad information, so we _must_ store
1049 * this information in a good / bad table during
1052 if (this->options
& NAND_IS_AND
) {
1053 /* Use the default pattern descriptors */
1054 if (!this->bbt_td
) {
1055 this->bbt_td
= &bbt_main_descr
;
1056 this->bbt_md
= &bbt_mirror_descr
;
1058 this->options
|= NAND_USE_FLASH_BBT
;
1059 return nand_scan_bbt (mtd
, &agand_flashbased
);
1063 /* Is a flash based bad block table requested ? */
1064 if (this->options
& NAND_USE_FLASH_BBT
) {
1065 /* Use the default pattern descriptors */
1066 if (!this->bbt_td
) {
1067 this->bbt_td
= &bbt_main_descr
;
1068 this->bbt_md
= &bbt_mirror_descr
;
1070 if (!this->badblock_pattern
) {
1071 this->badblock_pattern
= (mtd
->oobblock
> 512) ?
1072 &largepage_flashbased
: &smallpage_flashbased
;
1075 this->bbt_td
= NULL
;
1076 this->bbt_md
= NULL
;
1077 if (!this->badblock_pattern
) {
1078 this->badblock_pattern
= (mtd
->oobblock
> 512) ?
1079 &largepage_memorybased
: &smallpage_memorybased
;
1082 return nand_scan_bbt (mtd
, this->badblock_pattern
);
1086 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1087 * @mtd: MTD device structure
1088 * @offs: offset in the device
1089 * @allowbbt: allow access to bad block table region
1092 int nand_isbad_bbt (struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1094 struct nand_chip
*this = mtd
->priv
;
1098 /* Get block number * 2 */
1099 block
= (int) (offs
>> (this->bbt_erase_shift
- 1));
1100 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1102 DEBUG (MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n",
1103 (unsigned int)offs
, block
>> 1, res
);
1106 case 0x00: return 0;
1107 case 0x01: return 1;
1108 case 0x02: return allowbbt
? 0 : 1;
1113 EXPORT_SYMBOL (nand_scan_bbt
);
1114 EXPORT_SYMBOL (nand_default_bbt
);