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24 * If one of the bbt's is out of date or does not exist it is (re)created.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 #if defined(CONFIG_CMD_NAND) && !defined(CFG_NAND_LEGACY)
60 #include <linux/mtd/compat.h>
61 #include <linux/mtd/mtd.h>
62 #include <linux/mtd/nand.h>
64 #include <asm/errno.h>
68 #include <linux/slab.h>
69 #include <linux/types.h>
70 #include <linux/mtd/mtd.h>
71 #include <linux/mtd/nand.h>
72 #include <linux/mtd/nand_ecc.h>
73 #include <linux/mtd/compatmac.h>
74 #include <linux/bitops.h>
75 #include <linux/delay.h>
76 #include <linux/vmalloc.h>
80 * check_pattern - [GENERIC] check if a pattern is in the buffer
81 * @buf: the buffer to search
82 * @len: the length of buffer to search
83 * @paglen: the pagelength
84 * @td: search pattern descriptor
86 * Check for a pattern at the given place. Used to search bad block
87 * tables and good / bad block identifiers.
88 * If the SCAN_EMPTY option is set then check, if all bytes except the
89 * pattern area contain 0xff
92 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
97 end
= paglen
+ td
->offs
;
98 if (td
->options
& NAND_BBT_SCANEMPTY
) {
99 for (i
= 0; i
< end
; i
++) {
106 /* Compare the pattern */
107 for (i
= 0; i
< td
->len
; i
++) {
108 if (p
[i
] != td
->pattern
[i
])
112 if (td
->options
& NAND_BBT_SCANEMPTY
) {
115 for (i
= end
; i
< len
; i
++) {
124 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
125 * @buf: the buffer to search
126 * @td: search pattern descriptor
128 * Check for a pattern at the given place. Used to search bad block
129 * tables and good / bad block identifiers. Same as check_pattern, but
130 * no optional empty check
133 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
138 /* Compare the pattern */
139 for (i
= 0; i
< td
->len
; i
++) {
140 if (p
[td
->offs
+ i
] != td
->pattern
[i
])
147 * read_bbt - [GENERIC] Read the bad block table starting from page
148 * @mtd: MTD device structure
149 * @buf: temporary buffer
150 * @page: the starting page
151 * @num: the number of bbt descriptors to read
152 * @bits: number of bits per block
153 * @offs: offset in the memory table
154 * @reserved_block_code: Pattern to identify reserved blocks
156 * Read the bad block table starting from page.
159 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
160 int bits
, int offs
, int reserved_block_code
)
162 int res
, i
, j
, act
= 0;
163 struct nand_chip
*this = mtd
->priv
;
164 size_t retlen
, len
, totlen
;
166 uint8_t msk
= (uint8_t) ((1 << bits
) - 1);
168 totlen
= (num
* bits
) >> 3;
169 from
= ((loff_t
) page
) << this->page_shift
;
172 len
= min(totlen
, (size_t) (1 << this->bbt_erase_shift
));
173 res
= mtd
->read(mtd
, from
, len
, &retlen
, buf
);
176 printk(KERN_INFO
"nand_bbt: Error reading bad block table\n");
179 printk(KERN_WARNING
"nand_bbt: ECC error while reading bad block table\n");
183 for (i
= 0; i
< len
; i
++) {
184 uint8_t dat
= buf
[i
];
185 for (j
= 0; j
< 8; j
+= bits
, act
+= 2) {
186 uint8_t tmp
= (dat
>> j
) & msk
;
189 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
190 printk(KERN_DEBUG
"nand_read_bbt: Reserved block at 0x%08x\n",
191 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
192 this->bbt
[offs
+ (act
>> 3)] |= 0x2 << (act
& 0x06);
193 mtd
->ecc_stats
.bbtblocks
++;
196 /* Leave it for now, if its matured we can move this
197 * message to MTD_DEBUG_LEVEL0 */
198 printk(KERN_DEBUG
"nand_read_bbt: Bad block at 0x%08x\n",
199 ((offs
<< 2) + (act
>> 1)) << this->bbt_erase_shift
);
200 /* Factory marked bad or worn out ? */
202 this->bbt
[offs
+ (act
>> 3)] |= 0x3 << (act
& 0x06);
204 this->bbt
[offs
+ (act
>> 3)] |= 0x1 << (act
& 0x06);
205 mtd
->ecc_stats
.badblocks
++;
215 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
216 * @mtd: MTD device structure
217 * @buf: temporary buffer
218 * @td: descriptor for the bad block table
219 * @chip: read the table for a specific chip, -1 read all chips.
220 * Applies only if NAND_BBT_PERCHIP option is set
222 * Read the bad block table for all chips starting at a given page
223 * We assume that the bbt bits are in consecutive order.
225 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
227 struct nand_chip
*this = mtd
->priv
;
231 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
232 if (td
->options
& NAND_BBT_PERCHIP
) {
234 for (i
= 0; i
< this->numchips
; i
++) {
235 if (chip
== -1 || chip
== i
)
236 res
= read_bbt (mtd
, buf
, td
->pages
[i
], this->chipsize
>> this->bbt_erase_shift
, bits
, offs
, td
->reserved_block_code
);
239 offs
+= this->chipsize
>> (this->bbt_erase_shift
+ 2);
242 res
= read_bbt (mtd
, buf
, td
->pages
[0], mtd
->size
>> this->bbt_erase_shift
, bits
, 0, td
->reserved_block_code
);
250 * Scan read raw data from flash
252 static int scan_read_raw(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
255 struct mtd_oob_ops ops
;
257 ops
.mode
= MTD_OOB_RAW
;
259 ops
.ooblen
= mtd
->oobsize
;
264 return mtd
->read_oob(mtd
, offs
, &ops
);
268 * Scan write data with oob to flash
270 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
271 uint8_t *buf
, uint8_t *oob
)
273 struct mtd_oob_ops ops
;
275 ops
.mode
= MTD_OOB_PLACE
;
277 ops
.ooblen
= mtd
->oobsize
;
282 return mtd
->write_oob(mtd
, offs
, &ops
);
286 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
287 * @mtd: MTD device structure
288 * @buf: temporary buffer
289 * @td: descriptor for the bad block table
290 * @md: descriptor for the bad block table mirror
292 * Read the bad block table(s) for all chips starting at a given page
293 * We assume that the bbt bits are in consecutive order.
296 static int read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
297 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
299 struct nand_chip
*this = mtd
->priv
;
301 /* Read the primary version, if available */
302 if (td
->options
& NAND_BBT_VERSION
) {
303 scan_read_raw(mtd
, buf
, td
->pages
[0] << this->page_shift
,
305 td
->version
[0] = buf
[mtd
->writesize
+ td
->veroffs
];
306 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
307 td
->pages
[0], td
->version
[0]);
310 /* Read the mirror version, if available */
311 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
312 scan_read_raw(mtd
, buf
, md
->pages
[0] << this->page_shift
,
314 md
->version
[0] = buf
[mtd
->writesize
+ md
->veroffs
];
315 printk(KERN_DEBUG
"Bad block table at page %d, version 0x%02X\n",
316 md
->pages
[0], md
->version
[0]);
322 * Scan a given block full
324 static int scan_block_full(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
325 loff_t offs
, uint8_t *buf
, size_t readlen
,
326 int scanlen
, int len
)
330 ret
= scan_read_raw(mtd
, buf
, offs
, readlen
);
334 for (j
= 0; j
< len
; j
++, buf
+= scanlen
) {
335 if (check_pattern(buf
, scanlen
, mtd
->writesize
, bd
))
342 * Scan a given block partially
344 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
345 loff_t offs
, uint8_t *buf
, int len
)
347 struct mtd_oob_ops ops
;
350 ops
.ooblen
= mtd
->oobsize
;
354 ops
.mode
= MTD_OOB_PLACE
;
356 for (j
= 0; j
< len
; j
++) {
358 * Read the full oob until read_oob is fixed to
359 * handle single byte reads for 16 bit
362 ret
= mtd
->read_oob(mtd
, offs
, &ops
);
366 if (check_short_pattern(buf
, bd
))
369 offs
+= mtd
->writesize
;
375 * create_bbt - [GENERIC] Create a bad block table by scanning the device
376 * @mtd: MTD device structure
377 * @buf: temporary buffer
378 * @bd: descriptor for the good/bad block search pattern
379 * @chip: create the table for a specific chip, -1 read all chips.
380 * Applies only if NAND_BBT_PERCHIP option is set
382 * Create a bad block table by scanning the device
383 * for the given good/bad block identify pattern
385 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
386 struct nand_bbt_descr
*bd
, int chip
)
388 struct nand_chip
*this = mtd
->priv
;
389 int i
, numblocks
, len
, scanlen
;
394 printk(KERN_INFO
"Scanning device for bad blocks\n");
396 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
397 len
= 1 << (this->bbt_erase_shift
- this->page_shift
);
399 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
405 if (!(bd
->options
& NAND_BBT_SCANEMPTY
)) {
406 /* We need only read few bytes from the OOB area */
410 /* Full page content should be read */
411 scanlen
= mtd
->writesize
+ mtd
->oobsize
;
412 readlen
= len
* mtd
->writesize
;
416 /* Note that numblocks is 2 * (real numblocks) here, see i+=2
417 * below as it makes shifting and masking less painful */
418 numblocks
= mtd
->size
>> (this->bbt_erase_shift
- 1);
422 if (chip
>= this->numchips
) {
423 printk(KERN_WARNING
"create_bbt(): chipnr (%d) > available chips (%d)\n",
424 chip
+ 1, this->numchips
);
427 numblocks
= this->chipsize
>> (this->bbt_erase_shift
- 1);
428 startblock
= chip
* numblocks
;
429 numblocks
+= startblock
;
430 from
= startblock
<< (this->bbt_erase_shift
- 1);
433 for (i
= startblock
; i
< numblocks
;) {
436 if (bd
->options
& NAND_BBT_SCANALLPAGES
)
437 ret
= scan_block_full(mtd
, bd
, from
, buf
, readlen
,
440 ret
= scan_block_fast(mtd
, bd
, from
, buf
, len
);
446 this->bbt
[i
>> 3] |= 0x03 << (i
& 0x6);
447 printk(KERN_WARNING
"Bad eraseblock %d at 0x%08x\n",
448 i
>> 1, (unsigned int)from
);
449 mtd
->ecc_stats
.badblocks
++;
453 from
+= (1 << this->bbt_erase_shift
);
459 * search_bbt - [GENERIC] scan the device for a specific bad block table
460 * @mtd: MTD device structure
461 * @buf: temporary buffer
462 * @td: descriptor for the bad block table
464 * Read the bad block table by searching for a given ident pattern.
465 * Search is preformed either from the beginning up or from the end of
466 * the device downwards. The search starts always at the start of a
468 * If the option NAND_BBT_PERCHIP is given, each chip is searched
469 * for a bbt, which contains the bad block information of this chip.
470 * This is necessary to provide support for certain DOC devices.
472 * The bbt ident pattern resides in the oob area of the first page
475 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
477 struct nand_chip
*this = mtd
->priv
;
479 int bits
, startblock
, block
, dir
;
480 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
482 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
484 /* Search direction top -> down ? */
485 if (td
->options
& NAND_BBT_LASTBLOCK
) {
486 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
493 /* Do we have a bbt per chip ? */
494 if (td
->options
& NAND_BBT_PERCHIP
) {
495 chips
= this->numchips
;
496 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
497 startblock
&= bbtblocks
- 1;
500 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
503 /* Number of bits for each erase block in the bbt */
504 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
506 for (i
= 0; i
< chips
; i
++) {
507 /* Reset version information */
510 /* Scan the maximum number of blocks */
511 for (block
= 0; block
< td
->maxblocks
; block
++) {
513 int actblock
= startblock
+ dir
* block
;
514 loff_t offs
= actblock
<< this->bbt_erase_shift
;
516 /* Read first page */
517 scan_read_raw(mtd
, buf
, offs
, mtd
->writesize
);
518 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
519 td
->pages
[i
] = actblock
<< blocktopage
;
520 if (td
->options
& NAND_BBT_VERSION
) {
521 td
->version
[i
] = buf
[mtd
->writesize
+ td
->veroffs
];
526 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
528 /* Check, if we found a bbt for each requested chip */
529 for (i
= 0; i
< chips
; i
++) {
530 if (td
->pages
[i
] == -1)
531 printk(KERN_WARNING
"Bad block table not found for chip %d\n", i
);
533 printk(KERN_DEBUG
"Bad block table found at page %d, version 0x%02X\n", td
->pages
[i
],
540 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
541 * @mtd: MTD device structure
542 * @buf: temporary buffer
543 * @td: descriptor for the bad block table
544 * @md: descriptor for the bad block table mirror
546 * Search and read the bad block table(s)
548 static int search_read_bbts(struct mtd_info
*mtd
, uint8_t * buf
, struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
550 /* Search the primary table */
551 search_bbt(mtd
, buf
, td
);
553 /* Search the mirror table */
555 search_bbt(mtd
, buf
, md
);
557 /* Force result check */
562 * write_bbt - [GENERIC] (Re)write the bad block table
564 * @mtd: MTD device structure
565 * @buf: temporary buffer
566 * @td: descriptor for the bad block table
567 * @md: descriptor for the bad block table mirror
568 * @chipsel: selector for a specific chip, -1 for all
570 * (Re)write the bad block table
573 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
574 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
577 struct nand_chip
*this = mtd
->priv
;
578 struct erase_info einfo
;
579 int i
, j
, res
, chip
= 0;
580 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
581 int nrchips
, bbtoffs
, pageoffs
, ooboffs
;
583 uint8_t rcode
= td
->reserved_block_code
;
584 size_t retlen
, len
= 0;
586 struct mtd_oob_ops ops
;
588 ops
.ooblen
= mtd
->oobsize
;
591 ops
.mode
= MTD_OOB_PLACE
;
595 /* Write bad block table per chip rather than per device ? */
596 if (td
->options
& NAND_BBT_PERCHIP
) {
597 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
598 /* Full device write or specific chip ? */
600 nrchips
= this->numchips
;
602 nrchips
= chipsel
+ 1;
606 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
610 /* Loop through the chips */
611 for (; chip
< nrchips
; chip
++) {
613 /* There was already a version of the table, reuse the page
614 * This applies for absolute placement too, as we have the
615 * page nr. in td->pages.
617 if (td
->pages
[chip
] != -1) {
618 page
= td
->pages
[chip
];
622 /* Automatic placement of the bad block table */
623 /* Search direction top -> down ? */
624 if (td
->options
& NAND_BBT_LASTBLOCK
) {
625 startblock
= numblocks
* (chip
+ 1) - 1;
628 startblock
= chip
* numblocks
;
632 for (i
= 0; i
< td
->maxblocks
; i
++) {
633 int block
= startblock
+ dir
* i
;
634 /* Check, if the block is bad */
635 switch ((this->bbt
[block
>> 2] >>
636 (2 * (block
& 0x03))) & 0x03) {
642 (this->bbt_erase_shift
- this->page_shift
);
643 /* Check, if the block is used by the mirror table */
644 if (!md
|| md
->pages
[chip
] != page
)
647 printk(KERN_ERR
"No space left to write bad block table\n");
651 /* Set up shift count and masks for the flash table */
652 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
655 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
658 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
661 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
664 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
667 default: return -EINVAL
;
670 bbtoffs
= chip
* (numblocks
>> 2);
672 to
= ((loff_t
) page
) << this->page_shift
;
674 /* Must we save the block contents ? */
675 if (td
->options
& NAND_BBT_SAVECONTENT
) {
676 /* Make it block aligned */
677 to
&= ~((loff_t
) ((1 << this->bbt_erase_shift
) - 1));
678 len
= 1 << this->bbt_erase_shift
;
679 res
= mtd
->read(mtd
, to
, len
, &retlen
, buf
);
682 printk(KERN_INFO
"nand_bbt: Error "
683 "reading block for writing "
684 "the bad block table\n");
687 printk(KERN_WARNING
"nand_bbt: ECC error "
688 "while reading block for writing "
689 "bad block table\n");
692 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
693 ops
.oobbuf
= &buf
[len
];
694 res
= mtd
->read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
695 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
698 /* Calc the byte offset in the buffer */
699 pageoffs
= page
- (int)(to
>> this->page_shift
);
700 offs
= pageoffs
<< this->page_shift
;
701 /* Preset the bbt area with 0xff */
702 memset(&buf
[offs
], 0xff, (size_t) (numblocks
>> sft
));
703 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
707 len
= (size_t) (numblocks
>> sft
);
708 /* Make it page aligned ! */
709 len
= (len
+ (mtd
->writesize
- 1)) &
710 ~(mtd
->writesize
- 1);
711 /* Preset the buffer with 0xff */
712 memset(buf
, 0xff, len
+
713 (len
>> this->page_shift
)* mtd
->oobsize
);
716 /* Pattern is located in oob area of first page */
717 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
720 if (td
->options
& NAND_BBT_VERSION
)
721 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
723 /* walk through the memory table */
724 for (i
= 0; i
< numblocks
;) {
726 dat
= this->bbt
[bbtoffs
+ (i
>> 2)];
727 for (j
= 0; j
< 4; j
++, i
++) {
728 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
729 /* Do not store the reserved bbt blocks ! */
730 buf
[offs
+ (i
>> sft
)] &=
731 ~(msk
[dat
& 0x03] << sftcnt
);
736 memset(&einfo
, 0, sizeof(einfo
));
738 einfo
.addr
= (unsigned long)to
;
739 einfo
.len
= 1 << this->bbt_erase_shift
;
740 res
= nand_erase_nand(mtd
, &einfo
, 1);
744 res
= scan_write_bbt(mtd
, to
, len
, buf
, &buf
[len
]);
748 printk(KERN_DEBUG
"Bad block table written to 0x%08x, version "
749 "0x%02X\n", (unsigned int)to
, td
->version
[chip
]);
751 /* Mark it as used */
752 td
->pages
[chip
] = page
;
758 "nand_bbt: Error while writing bad block table %d\n", res
);
763 * nand_memory_bbt - [GENERIC] create a memory based bad block table
764 * @mtd: MTD device structure
765 * @bd: descriptor for the good/bad block search pattern
767 * The function creates a memory based bbt by scanning the device
768 * for manufacturer / software marked good / bad blocks
770 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
772 struct nand_chip
*this = mtd
->priv
;
774 bd
->options
&= ~NAND_BBT_SCANEMPTY
;
775 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
779 * check_create - [GENERIC] create and write bbt(s) if necessary
780 * @mtd: MTD device structure
781 * @buf: temporary buffer
782 * @bd: descriptor for the good/bad block search pattern
784 * The function checks the results of the previous call to read_bbt
785 * and creates / updates the bbt(s) if necessary
786 * Creation is necessary if no bbt was found for the chip/device
787 * Update is necessary if one of the tables is missing or the
788 * version nr. of one table is less than the other
790 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
792 int i
, chips
, writeops
, chipsel
, res
;
793 struct nand_chip
*this = mtd
->priv
;
794 struct nand_bbt_descr
*td
= this->bbt_td
;
795 struct nand_bbt_descr
*md
= this->bbt_md
;
796 struct nand_bbt_descr
*rd
, *rd2
;
798 /* Do we have a bbt per chip ? */
799 if (td
->options
& NAND_BBT_PERCHIP
)
800 chips
= this->numchips
;
804 for (i
= 0; i
< chips
; i
++) {
808 /* Per chip or per device ? */
809 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
810 /* Mirrored table avilable ? */
812 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
817 if (td
->pages
[i
] == -1) {
819 td
->version
[i
] = md
->version
[i
];
824 if (md
->pages
[i
] == -1) {
826 md
->version
[i
] = td
->version
[i
];
831 if (td
->version
[i
] == md
->version
[i
]) {
833 if (!(td
->options
& NAND_BBT_VERSION
))
838 if (((int8_t) (td
->version
[i
] - md
->version
[i
])) > 0) {
840 md
->version
[i
] = td
->version
[i
];
844 td
->version
[i
] = md
->version
[i
];
851 if (td
->pages
[i
] == -1) {
859 /* Create the bad block table by scanning the device ? */
860 if (!(td
->options
& NAND_BBT_CREATE
))
863 /* Create the table in memory by scanning the chip(s) */
864 create_bbt(mtd
, buf
, bd
, chipsel
);
870 /* read back first ? */
872 read_abs_bbt(mtd
, buf
, rd
, chipsel
);
873 /* If they weren't versioned, read both. */
875 read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
877 /* Write the bad block table to the device ? */
878 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
879 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
884 /* Write the mirror bad block table to the device ? */
885 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
886 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
895 * mark_bbt_regions - [GENERIC] mark the bad block table regions
896 * @mtd: MTD device structure
897 * @td: bad block table descriptor
899 * The bad block table regions are marked as "bad" to prevent
900 * accidental erasures / writes. The regions are identified by
903 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
905 struct nand_chip
*this = mtd
->priv
;
906 int i
, j
, chips
, block
, nrblocks
, update
;
907 uint8_t oldval
, newval
;
909 /* Do we have a bbt per chip ? */
910 if (td
->options
& NAND_BBT_PERCHIP
) {
911 chips
= this->numchips
;
912 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
915 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
918 for (i
= 0; i
< chips
; i
++) {
919 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
920 !(td
->options
& NAND_BBT_WRITE
)) {
921 if (td
->pages
[i
] == -1)
923 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
925 oldval
= this->bbt
[(block
>> 3)];
926 newval
= oldval
| (0x2 << (block
& 0x06));
927 this->bbt
[(block
>> 3)] = newval
;
928 if ((oldval
!= newval
) && td
->reserved_block_code
)
929 nand_update_bbt(mtd
, block
<< (this->bbt_erase_shift
- 1));
933 if (td
->options
& NAND_BBT_LASTBLOCK
)
934 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
936 block
= i
* nrblocks
;
938 for (j
= 0; j
< td
->maxblocks
; j
++) {
939 oldval
= this->bbt
[(block
>> 3)];
940 newval
= oldval
| (0x2 << (block
& 0x06));
941 this->bbt
[(block
>> 3)] = newval
;
942 if (oldval
!= newval
)
946 /* If we want reserved blocks to be recorded to flash, and some
947 new ones have been marked, then we need to update the stored
948 bbts. This should only happen once. */
949 if (update
&& td
->reserved_block_code
)
950 nand_update_bbt(mtd
, (block
- 2) << (this->bbt_erase_shift
- 1));
955 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
956 * @mtd: MTD device structure
957 * @bd: descriptor for the good/bad block search pattern
959 * The function checks, if a bad block table(s) is/are already
960 * available. If not it scans the device for manufacturer
961 * marked good / bad blocks and writes the bad block table(s) to
962 * the selected place.
964 * The bad block table memory is allocated here. It must be freed
965 * by calling the nand_free_bbt function.
968 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
970 struct nand_chip
*this = mtd
->priv
;
973 struct nand_bbt_descr
*td
= this->bbt_td
;
974 struct nand_bbt_descr
*md
= this->bbt_md
;
976 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
977 /* Allocate memory (2bit per block) and clear the memory bad block table */
978 this->bbt
= kzalloc(len
, GFP_KERNEL
);
980 printk(KERN_ERR
"nand_scan_bbt: Out of memory\n");
984 /* If no primary table decriptor is given, scan the device
985 * to build a memory based bad block table
988 if ((res
= nand_memory_bbt(mtd
, bd
))) {
989 printk(KERN_ERR
"nand_bbt: Can't scan flash and build the RAM-based BBT\n");
996 /* Allocate a temporary buffer for one eraseblock incl. oob */
997 len
= (1 << this->bbt_erase_shift
);
998 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1001 printk(KERN_ERR
"nand_bbt: Out of memory\n");
1007 /* Is the bbt at a given page ? */
1008 if (td
->options
& NAND_BBT_ABSPAGE
) {
1009 res
= read_abs_bbts(mtd
, buf
, td
, md
);
1011 /* Search the bad block table using a pattern in oob */
1012 res
= search_read_bbts(mtd
, buf
, td
, md
);
1016 res
= check_create(mtd
, buf
, bd
);
1018 /* Prevent the bbt regions from erasing / writing */
1019 mark_bbt_region(mtd
, td
);
1021 mark_bbt_region(mtd
, md
);
1028 * nand_update_bbt - [NAND Interface] update bad block table(s)
1029 * @mtd: MTD device structure
1030 * @offs: the offset of the newly marked block
1032 * The function updates the bad block table(s)
1034 int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1036 struct nand_chip
*this = mtd
->priv
;
1037 int len
, res
= 0, writeops
= 0;
1040 struct nand_bbt_descr
*td
= this->bbt_td
;
1041 struct nand_bbt_descr
*md
= this->bbt_md
;
1043 if (!this->bbt
|| !td
)
1046 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1047 /* Allocate a temporary buffer for one eraseblock incl. oob */
1048 len
= (1 << this->bbt_erase_shift
);
1049 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1050 buf
= kmalloc(len
, GFP_KERNEL
);
1052 printk(KERN_ERR
"nand_update_bbt: Out of memory\n");
1056 writeops
= md
!= NULL
? 0x03 : 0x01;
1058 /* Do we have a bbt per chip ? */
1059 if (td
->options
& NAND_BBT_PERCHIP
) {
1060 chip
= (int)(offs
>> this->chip_shift
);
1067 td
->version
[chip
]++;
1069 md
->version
[chip
]++;
1071 /* Write the bad block table to the device ? */
1072 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
1073 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1077 /* Write the mirror bad block table to the device ? */
1078 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
1079 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1087 /* Define some generic bad / good block scan pattern which are used
1088 * while scanning a device for factory marked good / bad blocks. */
1089 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1091 static struct nand_bbt_descr smallpage_memorybased
= {
1092 .options
= NAND_BBT_SCAN2NDPAGE
,
1095 .pattern
= scan_ff_pattern
1098 static struct nand_bbt_descr largepage_memorybased
= {
1102 .pattern
= scan_ff_pattern
1105 static struct nand_bbt_descr smallpage_flashbased
= {
1106 .options
= NAND_BBT_SCAN2NDPAGE
,
1109 .pattern
= scan_ff_pattern
1112 static struct nand_bbt_descr largepage_flashbased
= {
1113 .options
= NAND_BBT_SCAN2NDPAGE
,
1116 .pattern
= scan_ff_pattern
1119 static uint8_t scan_agand_pattern
[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 };
1121 static struct nand_bbt_descr agand_flashbased
= {
1122 .options
= NAND_BBT_SCANEMPTY
| NAND_BBT_SCANALLPAGES
,
1125 .pattern
= scan_agand_pattern
1128 /* Generic flash bbt decriptors
1130 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1131 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1133 static struct nand_bbt_descr bbt_main_descr
= {
1134 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1135 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1140 .pattern
= bbt_pattern
1143 static struct nand_bbt_descr bbt_mirror_descr
= {
1144 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1145 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1150 .pattern
= mirror_pattern
1154 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1155 * @mtd: MTD device structure
1157 * This function selects the default bad block table
1158 * support for the device and calls the nand_scan_bbt function
1161 int nand_default_bbt(struct mtd_info
*mtd
)
1163 struct nand_chip
*this = mtd
->priv
;
1165 /* Default for AG-AND. We must use a flash based
1166 * bad block table as the devices have factory marked
1167 * _good_ blocks. Erasing those blocks leads to loss
1168 * of the good / bad information, so we _must_ store
1169 * this information in a good / bad table during
1172 if (this->options
& NAND_IS_AND
) {
1173 /* Use the default pattern descriptors */
1174 if (!this->bbt_td
) {
1175 this->bbt_td
= &bbt_main_descr
;
1176 this->bbt_md
= &bbt_mirror_descr
;
1178 this->options
|= NAND_USE_FLASH_BBT
;
1179 return nand_scan_bbt(mtd
, &agand_flashbased
);
1182 /* Is a flash based bad block table requested ? */
1183 if (this->options
& NAND_USE_FLASH_BBT
) {
1184 /* Use the default pattern descriptors */
1185 if (!this->bbt_td
) {
1186 this->bbt_td
= &bbt_main_descr
;
1187 this->bbt_md
= &bbt_mirror_descr
;
1189 if (!this->badblock_pattern
) {
1190 this->badblock_pattern
= (mtd
->writesize
> 512) ? &largepage_flashbased
: &smallpage_flashbased
;
1193 this->bbt_td
= NULL
;
1194 this->bbt_md
= NULL
;
1195 if (!this->badblock_pattern
) {
1196 this->badblock_pattern
= (mtd
->writesize
> 512) ?
1197 &largepage_memorybased
: &smallpage_memorybased
;
1200 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1204 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1205 * @mtd: MTD device structure
1206 * @offs: offset in the device
1207 * @allowbbt: allow access to bad block table region
1210 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1212 struct nand_chip
*this = mtd
->priv
;
1216 /* Get block number * 2 */
1217 block
= (int)(offs
>> (this->bbt_erase_shift
- 1));
1218 res
= (this->bbt
[block
>> 3] >> (block
& 0x06)) & 0x03;
1220 MTDDEBUG (MTD_DEBUG_LEVEL2
, "nand_isbad_bbt(): bbt info for offs 0x%08x: "
1221 "(block %d) 0x%02x\n", (unsigned int)offs
, res
, block
>> 1);
1229 return allowbbt
? 0 : 1;
1234 /* XXX U-BOOT XXX */
1236 EXPORT_SYMBOL(nand_scan_bbt
);
1237 EXPORT_SYMBOL(nand_default_bbt
);