2 * drivers/mtd/nand_bbt.c
5 * Bad block table support for the NAND driver
7 * Copyright © 2004 Thomas Gleixner (tglx@linutronix.de)
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
15 * When nand_scan_bbt is called, then it tries to find the bad block table
16 * depending on the options in the BBT descriptor(s). If no flash based BBT
17 * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory
18 * marked good / bad blocks. This information is used to create a memory BBT.
19 * Once a new bad block is discovered then the "factory" information is updated
21 * If a flash based BBT is specified then the function first tries to find the
22 * BBT on flash. If a BBT is found then the contents are read and the memory
23 * based BBT is created. If a mirrored BBT is selected then the mirror is
24 * searched too and the versions are compared. If the mirror has a greater
25 * version number, then the mirror BBT is used to build the memory based BBT.
26 * If the tables are not versioned, then we "or" the bad block information.
27 * If one of the BBTs is out of date or does not exist it is (re)created.
28 * If no BBT exists at all then the device is scanned for factory marked
29 * good / bad blocks and the bad block tables are created.
31 * For manufacturer created BBTs like the one found on M-SYS DOC devices
32 * the BBT is searched and read but never created
34 * The auto generated bad block table is located in the last good blocks
35 * of the device. The table is mirrored, so it can be updated eventually.
36 * The table is marked in the OOB area with an ident pattern and a version
37 * number which indicates which of both tables is more up to date. If the NAND
38 * controller needs the complete OOB area for the ECC information then the
39 * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of
40 * course): it moves the ident pattern and the version byte into the data area
41 * and the OOB area will remain untouched.
43 * The table uses 2 bits per block
45 * 00b: block is factory marked bad
46 * 01b, 10b: block is marked bad due to wear
48 * The memory bad block table uses the following scheme:
50 * 01b: block is marked bad due to wear
51 * 10b: block is reserved (to protect the bbt area)
52 * 11b: block is factory marked bad
54 * Multichip devices like DOC store the bad block info per floor.
56 * Following assumptions are made:
57 * - bbts start at a page boundary, if autolocated on a block boundary
58 * - the space necessary for a bbt in FLASH does not exceed a block boundary
64 #include <linux/slab.h>
65 #include <linux/types.h>
66 #include <linux/mtd/mtd.h>
67 #include <linux/mtd/bbm.h>
68 #include <linux/mtd/nand.h>
69 #include <linux/mtd/nand_ecc.h>
70 #include <linux/bitops.h>
71 #include <linux/delay.h>
72 #include <linux/vmalloc.h>
73 #include <linux/export.h>
74 #include <linux/string.h>
78 #include <linux/compat.h>
80 #include <linux/mtd/mtd.h>
81 #include <linux/mtd/bbm.h>
82 #include <linux/mtd/nand.h>
83 #include <linux/mtd/nand_ecc.h>
84 #include <linux/bitops.h>
85 #include <linux/string.h>
88 #define BBT_BLOCK_GOOD 0x00
89 #define BBT_BLOCK_WORN 0x01
90 #define BBT_BLOCK_RESERVED 0x02
91 #define BBT_BLOCK_FACTORY_BAD 0x03
93 #define BBT_ENTRY_MASK 0x03
94 #define BBT_ENTRY_SHIFT 2
96 static int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
);
98 static inline uint8_t bbt_get_entry(struct nand_chip
*chip
, int block
)
100 uint8_t entry
= chip
->bbt
[block
>> BBT_ENTRY_SHIFT
];
101 entry
>>= (block
& BBT_ENTRY_MASK
) * 2;
102 return entry
& BBT_ENTRY_MASK
;
105 static inline void bbt_mark_entry(struct nand_chip
*chip
, int block
,
108 uint8_t msk
= (mark
& BBT_ENTRY_MASK
) << ((block
& BBT_ENTRY_MASK
) * 2);
109 chip
->bbt
[block
>> BBT_ENTRY_SHIFT
] |= msk
;
112 static int check_pattern_no_oob(uint8_t *buf
, struct nand_bbt_descr
*td
)
114 if (memcmp(buf
, td
->pattern
, td
->len
))
120 * check_pattern - [GENERIC] check if a pattern is in the buffer
121 * @buf: the buffer to search
122 * @len: the length of buffer to search
123 * @paglen: the pagelength
124 * @td: search pattern descriptor
126 * Check for a pattern at the given place. Used to search bad block tables and
127 * good / bad block identifiers.
129 static int check_pattern(uint8_t *buf
, int len
, int paglen
, struct nand_bbt_descr
*td
)
131 if (td
->options
& NAND_BBT_NO_OOB
)
132 return check_pattern_no_oob(buf
, td
);
134 /* Compare the pattern */
135 if (memcmp(buf
+ paglen
+ td
->offs
, td
->pattern
, td
->len
))
142 * check_short_pattern - [GENERIC] check if a pattern is in the buffer
143 * @buf: the buffer to search
144 * @td: search pattern descriptor
146 * Check for a pattern at the given place. Used to search bad block tables and
147 * good / bad block identifiers. Same as check_pattern, but no optional empty
150 static int check_short_pattern(uint8_t *buf
, struct nand_bbt_descr
*td
)
152 /* Compare the pattern */
153 if (memcmp(buf
+ td
->offs
, td
->pattern
, td
->len
))
159 * add_marker_len - compute the length of the marker in data area
160 * @td: BBT descriptor used for computation
162 * The length will be 0 if the marker is located in OOB area.
164 static u32
add_marker_len(struct nand_bbt_descr
*td
)
168 if (!(td
->options
& NAND_BBT_NO_OOB
))
172 if (td
->options
& NAND_BBT_VERSION
)
178 * read_bbt - [GENERIC] Read the bad block table starting from page
179 * @mtd: MTD device structure
180 * @buf: temporary buffer
181 * @page: the starting page
182 * @num: the number of bbt descriptors to read
183 * @td: the bbt describtion table
184 * @offs: block number offset in the table
186 * Read the bad block table starting from page.
188 static int read_bbt(struct mtd_info
*mtd
, uint8_t *buf
, int page
, int num
,
189 struct nand_bbt_descr
*td
, int offs
)
191 int res
, ret
= 0, i
, j
, act
= 0;
192 struct nand_chip
*this = mtd
->priv
;
193 size_t retlen
, len
, totlen
;
195 int bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
196 uint8_t msk
= (uint8_t)((1 << bits
) - 1);
198 int reserved_block_code
= td
->reserved_block_code
;
200 totlen
= (num
* bits
) >> 3;
201 marker_len
= add_marker_len(td
);
202 from
= ((loff_t
)page
) << this->page_shift
;
205 len
= min(totlen
, (size_t)(1 << this->bbt_erase_shift
));
208 * In case the BBT marker is not in the OOB area it
209 * will be just in the first page.
215 res
= mtd_read(mtd
, from
, len
, &retlen
, buf
);
217 if (mtd_is_eccerr(res
)) {
218 pr_info("nand_bbt: ECC error in BBT at "
219 "0x%012llx\n", from
& ~mtd
->writesize
);
221 } else if (mtd_is_bitflip(res
)) {
222 pr_info("nand_bbt: corrected error in BBT at "
223 "0x%012llx\n", from
& ~mtd
->writesize
);
226 pr_info("nand_bbt: error reading BBT\n");
232 for (i
= 0; i
< len
; i
++) {
233 uint8_t dat
= buf
[i
];
234 for (j
= 0; j
< 8; j
+= bits
, act
++) {
235 uint8_t tmp
= (dat
>> j
) & msk
;
238 if (reserved_block_code
&& (tmp
== reserved_block_code
)) {
239 pr_info("nand_read_bbt: reserved block at 0x%012llx\n",
240 (loff_t
)(offs
+ act
) <<
241 this->bbt_erase_shift
);
242 bbt_mark_entry(this, offs
+ act
,
244 mtd
->ecc_stats
.bbtblocks
++;
248 * Leave it for now, if it's matured we can
249 * move this message to pr_debug.
251 pr_info("nand_read_bbt: bad block at 0x%012llx\n",
252 (loff_t
)(offs
+ act
) <<
253 this->bbt_erase_shift
);
254 /* Factory marked bad or worn out? */
256 bbt_mark_entry(this, offs
+ act
,
257 BBT_BLOCK_FACTORY_BAD
);
259 bbt_mark_entry(this, offs
+ act
,
261 mtd
->ecc_stats
.badblocks
++;
271 * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page
272 * @mtd: MTD device structure
273 * @buf: temporary buffer
274 * @td: descriptor for the bad block table
275 * @chip: read the table for a specific chip, -1 read all chips; applies only if
276 * NAND_BBT_PERCHIP option is set
278 * Read the bad block table for all chips starting at a given page. We assume
279 * that the bbt bits are in consecutive order.
281 static int read_abs_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
, int chip
)
283 struct nand_chip
*this = mtd
->priv
;
286 if (td
->options
& NAND_BBT_PERCHIP
) {
288 for (i
= 0; i
< this->numchips
; i
++) {
289 if (chip
== -1 || chip
== i
)
290 res
= read_bbt(mtd
, buf
, td
->pages
[i
],
291 this->chipsize
>> this->bbt_erase_shift
,
295 offs
+= this->chipsize
>> this->bbt_erase_shift
;
298 res
= read_bbt(mtd
, buf
, td
->pages
[0],
299 mtd
->size
>> this->bbt_erase_shift
, td
, 0);
306 /* BBT marker is in the first page, no OOB */
307 static int scan_read_data(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
308 struct nand_bbt_descr
*td
)
314 if (td
->options
& NAND_BBT_VERSION
)
317 return mtd_read(mtd
, offs
, len
, &retlen
, buf
);
321 * scan_read_oob - [GENERIC] Scan data+OOB region to buffer
322 * @mtd: MTD device structure
323 * @buf: temporary buffer
324 * @offs: offset at which to scan
325 * @len: length of data region to read
327 * Scan read data from data+OOB. May traverse multiple pages, interleaving
328 * page,OOB,page,OOB,... in buf. Completes transfer and returns the "strongest"
329 * ECC condition (error or bitflip). May quit on the first (non-ECC) error.
331 static int scan_read_oob(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
334 struct mtd_oob_ops ops
;
337 ops
.mode
= MTD_OPS_PLACE_OOB
;
339 ops
.ooblen
= mtd
->oobsize
;
343 ops
.len
= min(len
, (size_t)mtd
->writesize
);
344 ops
.oobbuf
= buf
+ ops
.len
;
346 res
= mtd_read_oob(mtd
, offs
, &ops
);
348 if (!mtd_is_bitflip_or_eccerr(res
))
350 else if (mtd_is_eccerr(res
) || !ret
)
354 buf
+= mtd
->oobsize
+ mtd
->writesize
;
355 len
-= mtd
->writesize
;
356 offs
+= mtd
->writesize
;
361 static int scan_read(struct mtd_info
*mtd
, uint8_t *buf
, loff_t offs
,
362 size_t len
, struct nand_bbt_descr
*td
)
364 if (td
->options
& NAND_BBT_NO_OOB
)
365 return scan_read_data(mtd
, buf
, offs
, td
);
367 return scan_read_oob(mtd
, buf
, offs
, len
);
370 /* Scan write data with oob to flash */
371 static int scan_write_bbt(struct mtd_info
*mtd
, loff_t offs
, size_t len
,
372 uint8_t *buf
, uint8_t *oob
)
374 struct mtd_oob_ops ops
;
376 ops
.mode
= MTD_OPS_PLACE_OOB
;
378 ops
.ooblen
= mtd
->oobsize
;
383 return mtd_write_oob(mtd
, offs
, &ops
);
386 static u32
bbt_get_ver_offs(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
388 u32 ver_offs
= td
->veroffs
;
390 if (!(td
->options
& NAND_BBT_NO_OOB
))
391 ver_offs
+= mtd
->writesize
;
396 * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page
397 * @mtd: MTD device structure
398 * @buf: temporary buffer
399 * @td: descriptor for the bad block table
400 * @md: descriptor for the bad block table mirror
402 * Read the bad block table(s) for all chips starting at a given page. We
403 * assume that the bbt bits are in consecutive order.
405 static void read_abs_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
406 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
)
408 struct nand_chip
*this = mtd
->priv
;
410 /* Read the primary version, if available */
411 if (td
->options
& NAND_BBT_VERSION
) {
412 scan_read(mtd
, buf
, (loff_t
)td
->pages
[0] << this->page_shift
,
414 td
->version
[0] = buf
[bbt_get_ver_offs(mtd
, td
)];
415 pr_info("Bad block table at page %d, version 0x%02X\n",
416 td
->pages
[0], td
->version
[0]);
419 /* Read the mirror version, if available */
420 if (md
&& (md
->options
& NAND_BBT_VERSION
)) {
421 scan_read(mtd
, buf
, (loff_t
)md
->pages
[0] << this->page_shift
,
423 md
->version
[0] = buf
[bbt_get_ver_offs(mtd
, md
)];
424 pr_info("Bad block table at page %d, version 0x%02X\n",
425 md
->pages
[0], md
->version
[0]);
429 /* Scan a given block partially */
430 static int scan_block_fast(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
,
431 loff_t offs
, uint8_t *buf
, int numpages
)
433 struct mtd_oob_ops ops
;
436 ops
.ooblen
= mtd
->oobsize
;
440 ops
.mode
= MTD_OPS_PLACE_OOB
;
442 for (j
= 0; j
< numpages
; j
++) {
444 * Read the full oob until read_oob is fixed to handle single
445 * byte reads for 16 bit buswidth.
447 ret
= mtd_read_oob(mtd
, offs
, &ops
);
448 /* Ignore ECC errors when checking for BBM */
449 if (ret
&& !mtd_is_bitflip_or_eccerr(ret
))
452 if (check_short_pattern(buf
, bd
))
455 offs
+= mtd
->writesize
;
461 * create_bbt - [GENERIC] Create a bad block table by scanning the device
462 * @mtd: MTD device structure
463 * @buf: temporary buffer
464 * @bd: descriptor for the good/bad block search pattern
465 * @chip: create the table for a specific chip, -1 read all chips; applies only
466 * if NAND_BBT_PERCHIP option is set
468 * Create a bad block table by scanning the device for the given good/bad block
471 static int create_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
472 struct nand_bbt_descr
*bd
, int chip
)
474 struct nand_chip
*this = mtd
->priv
;
475 int i
, numblocks
, numpages
;
479 pr_info("Scanning device for bad blocks\n");
481 if (bd
->options
& NAND_BBT_SCAN2NDPAGE
)
487 numblocks
= mtd
->size
>> this->bbt_erase_shift
;
491 if (chip
>= this->numchips
) {
492 pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n",
493 chip
+ 1, this->numchips
);
496 numblocks
= this->chipsize
>> this->bbt_erase_shift
;
497 startblock
= chip
* numblocks
;
498 numblocks
+= startblock
;
499 from
= (loff_t
)startblock
<< this->bbt_erase_shift
;
502 if (this->bbt_options
& NAND_BBT_SCANLASTPAGE
)
503 from
+= mtd
->erasesize
- (mtd
->writesize
* numpages
);
505 for (i
= startblock
; i
< numblocks
; i
++) {
508 BUG_ON(bd
->options
& NAND_BBT_NO_OOB
);
510 ret
= scan_block_fast(mtd
, bd
, from
, buf
, numpages
);
515 bbt_mark_entry(this, i
, BBT_BLOCK_FACTORY_BAD
);
516 pr_warn("Bad eraseblock %d at 0x%012llx\n",
517 i
, (unsigned long long)from
);
518 mtd
->ecc_stats
.badblocks
++;
521 from
+= (1 << this->bbt_erase_shift
);
527 * search_bbt - [GENERIC] scan the device for a specific bad block table
528 * @mtd: MTD device structure
529 * @buf: temporary buffer
530 * @td: descriptor for the bad block table
532 * Read the bad block table by searching for a given ident pattern. Search is
533 * preformed either from the beginning up or from the end of the device
534 * downwards. The search starts always at the start of a block. If the option
535 * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains
536 * the bad block information of this chip. This is necessary to provide support
537 * for certain DOC devices.
539 * The bbt ident pattern resides in the oob area of the first page in a block.
541 static int search_bbt(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*td
)
543 struct nand_chip
*this = mtd
->priv
;
546 int bits
, startblock
, block
, dir
;
548 int startblock
, block
, dir
;
550 int scanlen
= mtd
->writesize
+ mtd
->oobsize
;
552 int blocktopage
= this->bbt_erase_shift
- this->page_shift
;
554 /* Search direction top -> down? */
555 if (td
->options
& NAND_BBT_LASTBLOCK
) {
556 startblock
= (mtd
->size
>> this->bbt_erase_shift
) - 1;
563 /* Do we have a bbt per chip? */
564 if (td
->options
& NAND_BBT_PERCHIP
) {
565 chips
= this->numchips
;
566 bbtblocks
= this->chipsize
>> this->bbt_erase_shift
;
567 startblock
&= bbtblocks
- 1;
570 bbtblocks
= mtd
->size
>> this->bbt_erase_shift
;
574 /* Number of bits for each erase block in the bbt */
575 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
578 for (i
= 0; i
< chips
; i
++) {
579 /* Reset version information */
582 /* Scan the maximum number of blocks */
583 for (block
= 0; block
< td
->maxblocks
; block
++) {
585 int actblock
= startblock
+ dir
* block
;
586 loff_t offs
= (loff_t
)actblock
<< this->bbt_erase_shift
;
588 /* Read first page */
589 scan_read(mtd
, buf
, offs
, mtd
->writesize
, td
);
590 if (!check_pattern(buf
, scanlen
, mtd
->writesize
, td
)) {
591 td
->pages
[i
] = actblock
<< blocktopage
;
592 if (td
->options
& NAND_BBT_VERSION
) {
593 offs
= bbt_get_ver_offs(mtd
, td
);
594 td
->version
[i
] = buf
[offs
];
599 startblock
+= this->chipsize
>> this->bbt_erase_shift
;
601 /* Check, if we found a bbt for each requested chip */
602 for (i
= 0; i
< chips
; i
++) {
603 if (td
->pages
[i
] == -1)
604 pr_warn("Bad block table not found for chip %d\n", i
);
606 pr_info("Bad block table found at page %d, version "
607 "0x%02X\n", td
->pages
[i
], td
->version
[i
]);
613 * search_read_bbts - [GENERIC] scan the device for bad block table(s)
614 * @mtd: MTD device structure
615 * @buf: temporary buffer
616 * @td: descriptor for the bad block table
617 * @md: descriptor for the bad block table mirror
619 * Search and read the bad block table(s).
621 static void search_read_bbts(struct mtd_info
*mtd
, uint8_t *buf
,
622 struct nand_bbt_descr
*td
,
623 struct nand_bbt_descr
*md
)
625 /* Search the primary table */
626 search_bbt(mtd
, buf
, td
);
628 /* Search the mirror table */
630 search_bbt(mtd
, buf
, md
);
634 * write_bbt - [GENERIC] (Re)write the bad block table
635 * @mtd: MTD device structure
636 * @buf: temporary buffer
637 * @td: descriptor for the bad block table
638 * @md: descriptor for the bad block table mirror
639 * @chipsel: selector for a specific chip, -1 for all
641 * (Re)write the bad block table.
643 static int write_bbt(struct mtd_info
*mtd
, uint8_t *buf
,
644 struct nand_bbt_descr
*td
, struct nand_bbt_descr
*md
,
647 struct nand_chip
*this = mtd
->priv
;
648 struct erase_info einfo
;
649 int i
, res
, chip
= 0;
650 int bits
, startblock
, dir
, page
, offs
, numblocks
, sft
, sftmsk
;
651 int nrchips
, pageoffs
, ooboffs
;
653 uint8_t rcode
= td
->reserved_block_code
;
654 size_t retlen
, len
= 0;
656 struct mtd_oob_ops ops
;
658 ops
.ooblen
= mtd
->oobsize
;
661 ops
.mode
= MTD_OPS_PLACE_OOB
;
665 /* Write bad block table per chip rather than per device? */
666 if (td
->options
& NAND_BBT_PERCHIP
) {
667 numblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
668 /* Full device write or specific chip? */
670 nrchips
= this->numchips
;
672 nrchips
= chipsel
+ 1;
676 numblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
680 /* Loop through the chips */
681 for (; chip
< nrchips
; chip
++) {
683 * There was already a version of the table, reuse the page
684 * This applies for absolute placement too, as we have the
685 * page nr. in td->pages.
687 if (td
->pages
[chip
] != -1) {
688 page
= td
->pages
[chip
];
693 * Automatic placement of the bad block table. Search direction
696 if (td
->options
& NAND_BBT_LASTBLOCK
) {
697 startblock
= numblocks
* (chip
+ 1) - 1;
700 startblock
= chip
* numblocks
;
704 for (i
= 0; i
< td
->maxblocks
; i
++) {
705 int block
= startblock
+ dir
* i
;
706 /* Check, if the block is bad */
707 switch (bbt_get_entry(this, block
)) {
709 case BBT_BLOCK_FACTORY_BAD
:
713 (this->bbt_erase_shift
- this->page_shift
);
714 /* Check, if the block is used by the mirror table */
715 if (!md
|| md
->pages
[chip
] != page
)
718 pr_err("No space left to write bad block table\n");
722 /* Set up shift count and masks for the flash table */
723 bits
= td
->options
& NAND_BBT_NRBITS_MSK
;
726 case 1: sft
= 3; sftmsk
= 0x07; msk
[0] = 0x00; msk
[1] = 0x01;
729 case 2: sft
= 2; sftmsk
= 0x06; msk
[0] = 0x00; msk
[1] = 0x01;
732 case 4: sft
= 1; sftmsk
= 0x04; msk
[0] = 0x00; msk
[1] = 0x0C;
735 case 8: sft
= 0; sftmsk
= 0x00; msk
[0] = 0x00; msk
[1] = 0x0F;
738 default: return -EINVAL
;
741 to
= ((loff_t
)page
) << this->page_shift
;
743 /* Must we save the block contents? */
744 if (td
->options
& NAND_BBT_SAVECONTENT
) {
745 /* Make it block aligned */
746 to
&= ~((loff_t
)((1 << this->bbt_erase_shift
) - 1));
747 len
= 1 << this->bbt_erase_shift
;
748 res
= mtd_read(mtd
, to
, len
, &retlen
, buf
);
751 pr_info("nand_bbt: error reading block "
752 "for writing the bad block table\n");
755 pr_warn("nand_bbt: ECC error while reading "
756 "block for writing bad block table\n");
759 ops
.ooblen
= (len
>> this->page_shift
) * mtd
->oobsize
;
760 ops
.oobbuf
= &buf
[len
];
761 res
= mtd_read_oob(mtd
, to
+ mtd
->writesize
, &ops
);
762 if (res
< 0 || ops
.oobretlen
!= ops
.ooblen
)
765 /* Calc the byte offset in the buffer */
766 pageoffs
= page
- (int)(to
>> this->page_shift
);
767 offs
= pageoffs
<< this->page_shift
;
768 /* Preset the bbt area with 0xff */
769 memset(&buf
[offs
], 0xff, (size_t)(numblocks
>> sft
));
770 ooboffs
= len
+ (pageoffs
* mtd
->oobsize
);
772 } else if (td
->options
& NAND_BBT_NO_OOB
) {
775 /* The version byte */
776 if (td
->options
& NAND_BBT_VERSION
)
779 len
= (size_t)(numblocks
>> sft
);
781 /* Make it page aligned! */
782 len
= ALIGN(len
, mtd
->writesize
);
783 /* Preset the buffer with 0xff */
784 memset(buf
, 0xff, len
);
785 /* Pattern is located at the begin of first page */
786 memcpy(buf
, td
->pattern
, td
->len
);
789 len
= (size_t)(numblocks
>> sft
);
790 /* Make it page aligned! */
791 len
= ALIGN(len
, mtd
->writesize
);
792 /* Preset the buffer with 0xff */
793 memset(buf
, 0xff, len
+
794 (len
>> this->page_shift
)* mtd
->oobsize
);
797 /* Pattern is located in oob area of first page */
798 memcpy(&buf
[ooboffs
+ td
->offs
], td
->pattern
, td
->len
);
801 if (td
->options
& NAND_BBT_VERSION
)
802 buf
[ooboffs
+ td
->veroffs
] = td
->version
[chip
];
804 /* Walk through the memory table */
805 for (i
= 0; i
< numblocks
; i
++) {
807 int sftcnt
= (i
<< (3 - sft
)) & sftmsk
;
808 dat
= bbt_get_entry(this, chip
* numblocks
+ i
);
809 /* Do not store the reserved bbt blocks! */
810 buf
[offs
+ (i
>> sft
)] &= ~(msk
[dat
] << sftcnt
);
813 memset(&einfo
, 0, sizeof(einfo
));
816 einfo
.len
= 1 << this->bbt_erase_shift
;
817 res
= nand_erase_nand(mtd
, &einfo
, 1);
821 res
= scan_write_bbt(mtd
, to
, len
, buf
,
822 td
->options
& NAND_BBT_NO_OOB
? NULL
:
827 pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
828 (unsigned long long)to
, td
->version
[chip
]);
830 /* Mark it as used */
831 td
->pages
[chip
] = page
;
836 pr_warn("nand_bbt: error while writing bad block table %d\n", res
);
841 * nand_memory_bbt - [GENERIC] create a memory based bad block table
842 * @mtd: MTD device structure
843 * @bd: descriptor for the good/bad block search pattern
845 * The function creates a memory based bbt by scanning the device for
846 * manufacturer / software marked good / bad blocks.
848 static inline int nand_memory_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
850 struct nand_chip
*this = mtd
->priv
;
852 return create_bbt(mtd
, this->buffers
->databuf
, bd
, -1);
856 * check_create - [GENERIC] create and write bbt(s) if necessary
857 * @mtd: MTD device structure
858 * @buf: temporary buffer
859 * @bd: descriptor for the good/bad block search pattern
861 * The function checks the results of the previous call to read_bbt and creates
862 * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found
863 * for the chip/device. Update is necessary if one of the tables is missing or
864 * the version nr. of one table is less than the other.
866 static int check_create(struct mtd_info
*mtd
, uint8_t *buf
, struct nand_bbt_descr
*bd
)
868 int i
, chips
, writeops
, create
, chipsel
, res
, res2
;
869 struct nand_chip
*this = mtd
->priv
;
870 struct nand_bbt_descr
*td
= this->bbt_td
;
871 struct nand_bbt_descr
*md
= this->bbt_md
;
872 struct nand_bbt_descr
*rd
, *rd2
;
874 /* Do we have a bbt per chip? */
875 if (td
->options
& NAND_BBT_PERCHIP
)
876 chips
= this->numchips
;
880 for (i
= 0; i
< chips
; i
++) {
886 /* Per chip or per device? */
887 chipsel
= (td
->options
& NAND_BBT_PERCHIP
) ? i
: -1;
888 /* Mirrored table available? */
890 if (td
->pages
[i
] == -1 && md
->pages
[i
] == -1) {
893 } else if (td
->pages
[i
] == -1) {
896 } else if (md
->pages
[i
] == -1) {
899 } else if (td
->version
[i
] == md
->version
[i
]) {
901 if (!(td
->options
& NAND_BBT_VERSION
))
903 } else if (((int8_t)(td
->version
[i
] - md
->version
[i
])) > 0) {
911 if (td
->pages
[i
] == -1) {
920 /* Create the bad block table by scanning the device? */
921 if (!(td
->options
& NAND_BBT_CREATE
))
924 /* Create the table in memory by scanning the chip(s) */
925 if (!(this->bbt_options
& NAND_BBT_CREATE_EMPTY
))
926 create_bbt(mtd
, buf
, bd
, chipsel
);
933 /* Read back first? */
935 res
= read_abs_bbt(mtd
, buf
, rd
, chipsel
);
936 if (mtd_is_eccerr(res
)) {
937 /* Mark table as invalid */
944 /* If they weren't versioned, read both */
946 res2
= read_abs_bbt(mtd
, buf
, rd2
, chipsel
);
947 if (mtd_is_eccerr(res2
)) {
948 /* Mark table as invalid */
956 /* Scrub the flash table(s)? */
957 if (mtd_is_bitflip(res
) || mtd_is_bitflip(res2
))
960 /* Update version numbers before writing */
962 td
->version
[i
] = max(td
->version
[i
], md
->version
[i
]);
963 md
->version
[i
] = td
->version
[i
];
966 /* Write the bad block table to the device? */
967 if ((writeops
& 0x01) && (td
->options
& NAND_BBT_WRITE
)) {
968 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
973 /* Write the mirror bad block table to the device? */
974 if ((writeops
& 0x02) && md
&& (md
->options
& NAND_BBT_WRITE
)) {
975 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
984 * mark_bbt_regions - [GENERIC] mark the bad block table regions
985 * @mtd: MTD device structure
986 * @td: bad block table descriptor
988 * The bad block table regions are marked as "bad" to prevent accidental
989 * erasures / writes. The regions are identified by the mark 0x02.
991 static void mark_bbt_region(struct mtd_info
*mtd
, struct nand_bbt_descr
*td
)
993 struct nand_chip
*this = mtd
->priv
;
994 int i
, j
, chips
, block
, nrblocks
, update
;
997 /* Do we have a bbt per chip? */
998 if (td
->options
& NAND_BBT_PERCHIP
) {
999 chips
= this->numchips
;
1000 nrblocks
= (int)(this->chipsize
>> this->bbt_erase_shift
);
1003 nrblocks
= (int)(mtd
->size
>> this->bbt_erase_shift
);
1006 for (i
= 0; i
< chips
; i
++) {
1007 if ((td
->options
& NAND_BBT_ABSPAGE
) ||
1008 !(td
->options
& NAND_BBT_WRITE
)) {
1009 if (td
->pages
[i
] == -1)
1011 block
= td
->pages
[i
] >> (this->bbt_erase_shift
- this->page_shift
);
1012 oldval
= bbt_get_entry(this, block
);
1013 bbt_mark_entry(this, block
, BBT_BLOCK_RESERVED
);
1014 if ((oldval
!= BBT_BLOCK_RESERVED
) &&
1015 td
->reserved_block_code
)
1016 nand_update_bbt(mtd
, (loff_t
)block
<<
1017 this->bbt_erase_shift
);
1021 if (td
->options
& NAND_BBT_LASTBLOCK
)
1022 block
= ((i
+ 1) * nrblocks
) - td
->maxblocks
;
1024 block
= i
* nrblocks
;
1025 for (j
= 0; j
< td
->maxblocks
; j
++) {
1026 oldval
= bbt_get_entry(this, block
);
1027 bbt_mark_entry(this, block
, BBT_BLOCK_RESERVED
);
1028 if (oldval
!= BBT_BLOCK_RESERVED
)
1033 * If we want reserved blocks to be recorded to flash, and some
1034 * new ones have been marked, then we need to update the stored
1035 * bbts. This should only happen once.
1037 if (update
&& td
->reserved_block_code
)
1038 nand_update_bbt(mtd
, (loff_t
)(block
- 1) <<
1039 this->bbt_erase_shift
);
1044 * verify_bbt_descr - verify the bad block description
1045 * @mtd: MTD device structure
1046 * @bd: the table to verify
1048 * This functions performs a few sanity checks on the bad block description
1051 static void verify_bbt_descr(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1053 struct nand_chip
*this = mtd
->priv
;
1061 pattern_len
= bd
->len
;
1062 bits
= bd
->options
& NAND_BBT_NRBITS_MSK
;
1064 BUG_ON((this->bbt_options
& NAND_BBT_NO_OOB
) &&
1065 !(this->bbt_options
& NAND_BBT_USE_FLASH
));
1068 if (bd
->options
& NAND_BBT_VERSION
)
1071 if (bd
->options
& NAND_BBT_NO_OOB
) {
1072 BUG_ON(!(this->bbt_options
& NAND_BBT_USE_FLASH
));
1073 BUG_ON(!(this->bbt_options
& NAND_BBT_NO_OOB
));
1075 if (bd
->options
& NAND_BBT_VERSION
)
1076 BUG_ON(bd
->veroffs
!= bd
->len
);
1077 BUG_ON(bd
->options
& NAND_BBT_SAVECONTENT
);
1080 if (bd
->options
& NAND_BBT_PERCHIP
)
1081 table_size
= this->chipsize
>> this->bbt_erase_shift
;
1083 table_size
= mtd
->size
>> this->bbt_erase_shift
;
1086 if (bd
->options
& NAND_BBT_NO_OOB
)
1087 table_size
+= pattern_len
;
1088 BUG_ON(table_size
> (1 << this->bbt_erase_shift
));
1092 * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s)
1093 * @mtd: MTD device structure
1094 * @bd: descriptor for the good/bad block search pattern
1096 * The function checks, if a bad block table(s) is/are already available. If
1097 * not it scans the device for manufacturer marked good / bad blocks and writes
1098 * the bad block table(s) to the selected place.
1100 * The bad block table memory is allocated here. It must be freed by calling
1101 * the nand_free_bbt function.
1103 int nand_scan_bbt(struct mtd_info
*mtd
, struct nand_bbt_descr
*bd
)
1105 struct nand_chip
*this = mtd
->priv
;
1108 struct nand_bbt_descr
*td
= this->bbt_td
;
1109 struct nand_bbt_descr
*md
= this->bbt_md
;
1111 len
= mtd
->size
>> (this->bbt_erase_shift
+ 2);
1113 * Allocate memory (2bit per block) and clear the memory bad block
1116 this->bbt
= kzalloc(len
, GFP_KERNEL
);
1121 * If no primary table decriptor is given, scan the device to build a
1122 * memory based bad block table.
1125 if ((res
= nand_memory_bbt(mtd
, bd
))) {
1126 pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
1132 verify_bbt_descr(mtd
, td
);
1133 verify_bbt_descr(mtd
, md
);
1135 /* Allocate a temporary buffer for one eraseblock incl. oob */
1136 len
= (1 << this->bbt_erase_shift
);
1137 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1145 /* Is the bbt at a given page? */
1146 if (td
->options
& NAND_BBT_ABSPAGE
) {
1147 read_abs_bbts(mtd
, buf
, td
, md
);
1149 /* Search the bad block table using a pattern in oob */
1150 search_read_bbts(mtd
, buf
, td
, md
);
1153 res
= check_create(mtd
, buf
, bd
);
1155 /* Prevent the bbt regions from erasing / writing */
1156 mark_bbt_region(mtd
, td
);
1158 mark_bbt_region(mtd
, md
);
1165 * nand_update_bbt - update bad block table(s)
1166 * @mtd: MTD device structure
1167 * @offs: the offset of the newly marked block
1169 * The function updates the bad block table(s).
1171 static int nand_update_bbt(struct mtd_info
*mtd
, loff_t offs
)
1173 struct nand_chip
*this = mtd
->priv
;
1177 struct nand_bbt_descr
*td
= this->bbt_td
;
1178 struct nand_bbt_descr
*md
= this->bbt_md
;
1180 if (!this->bbt
|| !td
)
1183 /* Allocate a temporary buffer for one eraseblock incl. oob */
1184 len
= (1 << this->bbt_erase_shift
);
1185 len
+= (len
>> this->page_shift
) * mtd
->oobsize
;
1186 buf
= kmalloc(len
, GFP_KERNEL
);
1190 /* Do we have a bbt per chip? */
1191 if (td
->options
& NAND_BBT_PERCHIP
) {
1192 chip
= (int)(offs
>> this->chip_shift
);
1199 td
->version
[chip
]++;
1201 md
->version
[chip
]++;
1203 /* Write the bad block table to the device? */
1204 if (td
->options
& NAND_BBT_WRITE
) {
1205 res
= write_bbt(mtd
, buf
, td
, md
, chipsel
);
1209 /* Write the mirror bad block table to the device? */
1210 if (md
&& (md
->options
& NAND_BBT_WRITE
)) {
1211 res
= write_bbt(mtd
, buf
, md
, td
, chipsel
);
1220 * Define some generic bad / good block scan pattern which are used
1221 * while scanning a device for factory marked good / bad blocks.
1223 static uint8_t scan_ff_pattern
[] = { 0xff, 0xff };
1225 /* Generic flash bbt descriptors */
1226 static uint8_t bbt_pattern
[] = {'B', 'b', 't', '0' };
1227 static uint8_t mirror_pattern
[] = {'1', 't', 'b', 'B' };
1229 static struct nand_bbt_descr bbt_main_descr
= {
1230 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1231 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1235 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1236 .pattern
= bbt_pattern
1239 static struct nand_bbt_descr bbt_mirror_descr
= {
1240 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1241 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
,
1245 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1246 .pattern
= mirror_pattern
1249 static struct nand_bbt_descr bbt_main_no_oob_descr
= {
1250 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1251 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1255 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1256 .pattern
= bbt_pattern
1259 static struct nand_bbt_descr bbt_mirror_no_oob_descr
= {
1260 .options
= NAND_BBT_LASTBLOCK
| NAND_BBT_CREATE
| NAND_BBT_WRITE
1261 | NAND_BBT_2BIT
| NAND_BBT_VERSION
| NAND_BBT_PERCHIP
1265 .maxblocks
= NAND_BBT_SCAN_MAXBLOCKS
,
1266 .pattern
= mirror_pattern
1269 #define BADBLOCK_SCAN_MASK (~NAND_BBT_NO_OOB)
1271 * nand_create_badblock_pattern - [INTERN] Creates a BBT descriptor structure
1272 * @this: NAND chip to create descriptor for
1274 * This function allocates and initializes a nand_bbt_descr for BBM detection
1275 * based on the properties of @this. The new descriptor is stored in
1276 * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when
1277 * passed to this function.
1279 static int nand_create_badblock_pattern(struct nand_chip
*this)
1281 struct nand_bbt_descr
*bd
;
1282 if (this->badblock_pattern
) {
1283 pr_warn("Bad block pattern already allocated; not replacing\n");
1286 bd
= kzalloc(sizeof(*bd
), GFP_KERNEL
);
1289 bd
->options
= this->bbt_options
& BADBLOCK_SCAN_MASK
;
1290 bd
->offs
= this->badblockpos
;
1291 bd
->len
= (this->options
& NAND_BUSWIDTH_16
) ? 2 : 1;
1292 bd
->pattern
= scan_ff_pattern
;
1293 bd
->options
|= NAND_BBT_DYNAMICSTRUCT
;
1294 this->badblock_pattern
= bd
;
1299 * nand_default_bbt - [NAND Interface] Select a default bad block table for the device
1300 * @mtd: MTD device structure
1302 * This function selects the default bad block table support for the device and
1303 * calls the nand_scan_bbt function.
1305 int nand_default_bbt(struct mtd_info
*mtd
)
1307 struct nand_chip
*this = mtd
->priv
;
1309 /* Is a flash based bad block table requested? */
1310 if (this->bbt_options
& NAND_BBT_USE_FLASH
) {
1311 /* Use the default pattern descriptors */
1312 if (!this->bbt_td
) {
1313 if (this->bbt_options
& NAND_BBT_NO_OOB
) {
1314 this->bbt_td
= &bbt_main_no_oob_descr
;
1315 this->bbt_md
= &bbt_mirror_no_oob_descr
;
1317 this->bbt_td
= &bbt_main_descr
;
1318 this->bbt_md
= &bbt_mirror_descr
;
1322 this->bbt_td
= NULL
;
1323 this->bbt_md
= NULL
;
1326 if (!this->badblock_pattern
)
1327 nand_create_badblock_pattern(this);
1329 return nand_scan_bbt(mtd
, this->badblock_pattern
);
1333 * nand_isbad_bbt - [NAND Interface] Check if a block is bad
1334 * @mtd: MTD device structure
1335 * @offs: offset in the device
1336 * @allowbbt: allow access to bad block table region
1338 int nand_isbad_bbt(struct mtd_info
*mtd
, loff_t offs
, int allowbbt
)
1340 struct nand_chip
*this = mtd
->priv
;
1343 block
= (int)(offs
>> this->bbt_erase_shift
);
1344 res
= bbt_get_entry(this, block
);
1346 pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: "
1347 "(block %d) 0x%02x\n",
1348 (unsigned int)offs
, block
, res
);
1351 case BBT_BLOCK_GOOD
:
1353 case BBT_BLOCK_WORN
:
1355 case BBT_BLOCK_RESERVED
:
1356 return allowbbt
? 0 : 1;
1362 * nand_markbad_bbt - [NAND Interface] Mark a block bad in the BBT
1363 * @mtd: MTD device structure
1364 * @offs: offset of the bad block
1366 int nand_markbad_bbt(struct mtd_info
*mtd
, loff_t offs
)
1368 struct nand_chip
*this = mtd
->priv
;
1371 block
= (int)(offs
>> this->bbt_erase_shift
);
1373 /* Mark bad block in memory */
1374 bbt_mark_entry(this, block
, BBT_BLOCK_WORN
);
1376 /* Update flash-based bad block table */
1377 if (this->bbt_options
& NAND_BBT_USE_FLASH
)
1378 ret
= nand_update_bbt(mtd
, offs
);
1383 EXPORT_SYMBOL(nand_scan_bbt
);