Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * drivers/mtd/nand_bbt.c | |
3 | * | |
4 | * Overview: | |
5 | * Bad block table support for the NAND driver | |
61b03bd7 | 6 | * |
1da177e4 LT |
7 | * Copyright (C) 2004 Thomas Gleixner (tglx@linutronix.de) |
8 | * | |
1da177e4 LT |
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. | |
12 | * | |
13 | * Description: | |
14 | * | |
61b03bd7 | 15 | * When nand_scan_bbt is called, then it tries to find the bad block table |
7cba7b14 | 16 | * depending on the options in the BBT descriptor(s). If no flash based BBT |
bb9ebd4e | 17 | * (NAND_BBT_USE_FLASH) is specified then the device is scanned for factory |
7cba7b14 SAS |
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 | |
20 | * on the device. | |
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 than the mirror BBT is used to build the memory based BBT. | |
1da177e4 | 26 | * If the tables are not versioned, then we "or" the bad block information. |
7cba7b14 SAS |
27 | * If one of the BBTs is out of date or does not exist it is (re)created.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 | |
61b03bd7 | 29 | * good / bad blocks and the bad block tables are created. |
1da177e4 | 30 | * |
7cba7b14 SAS |
31 | * For manufacturer created BBTs like the one found on M-SYS DOC devices |
32 | * the BBT is searched and read but never created | |
1da177e4 | 33 | * |
7cba7b14 | 34 | * The auto generated bad block table is located in the last good blocks |
61b03bd7 | 35 | * of the device. The table is mirrored, so it can be updated eventually. |
7cba7b14 SAS |
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 | |
bb9ebd4e | 39 | * option NAND_BBT_NO_OOB should be used (along with NAND_BBT_USE_FLASH, of |
a40f7341 BN |
40 | * course): it moves the ident pattern and the version byte into the data area |
41 | * and the OOB area will remain untouched. | |
1da177e4 LT |
42 | * |
43 | * The table uses 2 bits per block | |
7cba7b14 SAS |
44 | * 11b: block is good |
45 | * 00b: block is factory marked bad | |
46 | * 01b, 10b: block is marked bad due to wear | |
1da177e4 LT |
47 | * |
48 | * The memory bad block table uses the following scheme: | |
49 | * 00b: block is good | |
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 | |
61b03bd7 | 53 | * |
1da177e4 LT |
54 | * Multichip devices like DOC store the bad block info per floor. |
55 | * | |
56 | * Following assumptions are made: | |
57 | * - bbts start at a page boundary, if autolocated on a block boundary | |
e0c7d767 | 58 | * - the space necessary for a bbt in FLASH does not exceed a block boundary |
61b03bd7 | 59 | * |
1da177e4 LT |
60 | */ |
61 | ||
62 | #include <linux/slab.h> | |
63 | #include <linux/types.h> | |
64 | #include <linux/mtd/mtd.h> | |
65 | #include <linux/mtd/nand.h> | |
66 | #include <linux/mtd/nand_ecc.h> | |
1da177e4 LT |
67 | #include <linux/bitops.h> |
68 | #include <linux/delay.h> | |
c3f8abf4 | 69 | #include <linux/vmalloc.h> |
1da177e4 | 70 | |
7cba7b14 SAS |
71 | static int check_pattern_no_oob(uint8_t *buf, struct nand_bbt_descr *td) |
72 | { | |
73 | int ret; | |
74 | ||
75 | ret = memcmp(buf, td->pattern, td->len); | |
76 | if (!ret) | |
77 | return ret; | |
78 | return -1; | |
79 | } | |
80 | ||
61b03bd7 | 81 | /** |
1da177e4 | 82 | * check_pattern - [GENERIC] check if a pattern is in the buffer |
8b6e50c9 BN |
83 | * @buf: the buffer to search |
84 | * @len: the length of buffer to search | |
85 | * @paglen: the pagelength | |
86 | * @td: search pattern descriptor | |
1da177e4 | 87 | * |
8b6e50c9 BN |
88 | * Check for a pattern at the given place. Used to search bad block tables and |
89 | * good / bad block identifiers. If the SCAN_EMPTY option is set then check, if | |
90 | * all bytes except the pattern area contain 0xff. | |
91 | */ | |
e0c7d767 | 92 | static int check_pattern(uint8_t *buf, int len, int paglen, struct nand_bbt_descr *td) |
1da177e4 | 93 | { |
171650af | 94 | int i, end = 0; |
1da177e4 LT |
95 | uint8_t *p = buf; |
96 | ||
7cba7b14 SAS |
97 | if (td->options & NAND_BBT_NO_OOB) |
98 | return check_pattern_no_oob(buf, td); | |
99 | ||
c9e05365 | 100 | end = paglen + td->offs; |
1da177e4 LT |
101 | if (td->options & NAND_BBT_SCANEMPTY) { |
102 | for (i = 0; i < end; i++) { | |
103 | if (p[i] != 0xff) | |
104 | return -1; | |
105 | } | |
61b03bd7 | 106 | } |
c9e05365 | 107 | p += end; |
61b03bd7 | 108 | |
1da177e4 LT |
109 | /* Compare the pattern */ |
110 | for (i = 0; i < td->len; i++) { | |
111 | if (p[i] != td->pattern[i]) | |
112 | return -1; | |
113 | } | |
114 | ||
1da177e4 | 115 | if (td->options & NAND_BBT_SCANEMPTY) { |
171650af AB |
116 | p += td->len; |
117 | end += td->len; | |
1da177e4 LT |
118 | for (i = end; i < len; i++) { |
119 | if (*p++ != 0xff) | |
120 | return -1; | |
121 | } | |
122 | } | |
123 | return 0; | |
124 | } | |
125 | ||
61b03bd7 | 126 | /** |
c9e05365 | 127 | * check_short_pattern - [GENERIC] check if a pattern is in the buffer |
8b6e50c9 BN |
128 | * @buf: the buffer to search |
129 | * @td: search pattern descriptor | |
c9e05365 | 130 | * |
8b6e50c9 BN |
131 | * Check for a pattern at the given place. Used to search bad block tables and |
132 | * good / bad block identifiers. Same as check_pattern, but no optional empty | |
133 | * check. | |
134 | */ | |
e0c7d767 | 135 | static int check_short_pattern(uint8_t *buf, struct nand_bbt_descr *td) |
c9e05365 TG |
136 | { |
137 | int i; | |
138 | uint8_t *p = buf; | |
139 | ||
140 | /* Compare the pattern */ | |
141 | for (i = 0; i < td->len; i++) { | |
19870da7 | 142 | if (p[td->offs + i] != td->pattern[i]) |
c9e05365 TG |
143 | return -1; |
144 | } | |
145 | return 0; | |
146 | } | |
147 | ||
7cba7b14 SAS |
148 | /** |
149 | * add_marker_len - compute the length of the marker in data area | |
8b6e50c9 | 150 | * @td: BBT descriptor used for computation |
7cba7b14 | 151 | * |
7854d3f7 | 152 | * The length will be 0 if the marker is located in OOB area. |
7cba7b14 SAS |
153 | */ |
154 | static u32 add_marker_len(struct nand_bbt_descr *td) | |
155 | { | |
156 | u32 len; | |
157 | ||
158 | if (!(td->options & NAND_BBT_NO_OOB)) | |
159 | return 0; | |
160 | ||
161 | len = td->len; | |
162 | if (td->options & NAND_BBT_VERSION) | |
163 | len++; | |
164 | return len; | |
165 | } | |
166 | ||
1da177e4 LT |
167 | /** |
168 | * read_bbt - [GENERIC] Read the bad block table starting from page | |
8b6e50c9 BN |
169 | * @mtd: MTD device structure |
170 | * @buf: temporary buffer | |
171 | * @page: the starting page | |
172 | * @num: the number of bbt descriptors to read | |
7854d3f7 | 173 | * @td: the bbt describtion table |
8b6e50c9 | 174 | * @offs: offset in the memory table |
1da177e4 LT |
175 | * |
176 | * Read the bad block table starting from page. | |
1da177e4 | 177 | */ |
e0c7d767 | 178 | static int read_bbt(struct mtd_info *mtd, uint8_t *buf, int page, int num, |
df5b4e34 | 179 | struct nand_bbt_descr *td, int offs) |
1da177e4 LT |
180 | { |
181 | int res, i, j, act = 0; | |
182 | struct nand_chip *this = mtd->priv; | |
183 | size_t retlen, len, totlen; | |
184 | loff_t from; | |
df5b4e34 | 185 | int bits = td->options & NAND_BBT_NRBITS_MSK; |
1da177e4 | 186 | uint8_t msk = (uint8_t) ((1 << bits) - 1); |
7cba7b14 | 187 | u32 marker_len; |
df5b4e34 | 188 | int reserved_block_code = td->reserved_block_code; |
1da177e4 LT |
189 | |
190 | totlen = (num * bits) >> 3; | |
7cba7b14 | 191 | marker_len = add_marker_len(td); |
e0c7d767 | 192 | from = ((loff_t) page) << this->page_shift; |
61b03bd7 | 193 | |
1da177e4 | 194 | while (totlen) { |
e0c7d767 | 195 | len = min(totlen, (size_t) (1 << this->bbt_erase_shift)); |
7cba7b14 SAS |
196 | if (marker_len) { |
197 | /* | |
198 | * In case the BBT marker is not in the OOB area it | |
199 | * will be just in the first page. | |
200 | */ | |
201 | len -= marker_len; | |
202 | from += marker_len; | |
203 | marker_len = 0; | |
204 | } | |
9223a456 | 205 | res = mtd->read(mtd, from, len, &retlen, buf); |
1da177e4 LT |
206 | if (res < 0) { |
207 | if (retlen != len) { | |
e0c7d767 | 208 | printk(KERN_INFO "nand_bbt: Error reading bad block table\n"); |
1da177e4 LT |
209 | return res; |
210 | } | |
e0c7d767 | 211 | printk(KERN_WARNING "nand_bbt: ECC error while reading bad block table\n"); |
61b03bd7 | 212 | } |
1da177e4 LT |
213 | |
214 | /* Analyse data */ | |
215 | for (i = 0; i < len; i++) { | |
216 | uint8_t dat = buf[i]; | |
217 | for (j = 0; j < 8; j += bits, act += 2) { | |
218 | uint8_t tmp = (dat >> j) & msk; | |
219 | if (tmp == msk) | |
220 | continue; | |
e0c7d767 | 221 | if (reserved_block_code && (tmp == reserved_block_code)) { |
69423d99 AH |
222 | printk(KERN_DEBUG "nand_read_bbt: Reserved block at 0x%012llx\n", |
223 | (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); | |
1da177e4 | 224 | this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06); |
f1a28c02 | 225 | mtd->ecc_stats.bbtblocks++; |
1da177e4 LT |
226 | continue; |
227 | } | |
8b6e50c9 BN |
228 | /* |
229 | * Leave it for now, if it's matured we can | |
230 | * move this message to MTD_DEBUG_LEVEL0. | |
231 | */ | |
69423d99 AH |
232 | printk(KERN_DEBUG "nand_read_bbt: Bad block at 0x%012llx\n", |
233 | (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); | |
8b6e50c9 | 234 | /* Factory marked bad or worn out? */ |
1da177e4 LT |
235 | if (tmp == 0) |
236 | this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06); | |
237 | else | |
238 | this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06); | |
f1a28c02 | 239 | mtd->ecc_stats.badblocks++; |
61b03bd7 | 240 | } |
1da177e4 LT |
241 | } |
242 | totlen -= len; | |
243 | from += len; | |
244 | } | |
245 | return 0; | |
246 | } | |
247 | ||
248 | /** | |
249 | * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page | |
8b6e50c9 BN |
250 | * @mtd: MTD device structure |
251 | * @buf: temporary buffer | |
252 | * @td: descriptor for the bad block table | |
253 | * @chip: read the table for a specific chip, -1 read all chips; aplies only if | |
254 | * NAND_BBT_PERCHIP option is set | |
1da177e4 | 255 | * |
8b6e50c9 BN |
256 | * Read the bad block table for all chips starting at a given page. We assume |
257 | * that the bbt bits are in consecutive order. | |
258 | */ | |
e0c7d767 | 259 | static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip) |
1da177e4 LT |
260 | { |
261 | struct nand_chip *this = mtd->priv; | |
262 | int res = 0, i; | |
1da177e4 | 263 | |
1da177e4 LT |
264 | if (td->options & NAND_BBT_PERCHIP) { |
265 | int offs = 0; | |
266 | for (i = 0; i < this->numchips; i++) { | |
267 | if (chip == -1 || chip == i) | |
df5b4e34 SAS |
268 | res = read_bbt(mtd, buf, td->pages[i], |
269 | this->chipsize >> this->bbt_erase_shift, | |
270 | td, offs); | |
1da177e4 LT |
271 | if (res) |
272 | return res; | |
273 | offs += this->chipsize >> (this->bbt_erase_shift + 2); | |
274 | } | |
275 | } else { | |
df5b4e34 SAS |
276 | res = read_bbt(mtd, buf, td->pages[0], |
277 | mtd->size >> this->bbt_erase_shift, td, 0); | |
1da177e4 LT |
278 | if (res) |
279 | return res; | |
280 | } | |
281 | return 0; | |
282 | } | |
283 | ||
8b6e50c9 | 284 | /* BBT marker is in the first page, no OOB */ |
7cba7b14 SAS |
285 | static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |
286 | struct nand_bbt_descr *td) | |
287 | { | |
288 | size_t retlen; | |
289 | size_t len; | |
290 | ||
291 | len = td->len; | |
292 | if (td->options & NAND_BBT_VERSION) | |
293 | len++; | |
294 | ||
295 | return mtd->read(mtd, offs, len, &retlen, buf); | |
296 | } | |
297 | ||
8b6e50c9 | 298 | /* Scan read raw data from flash */ |
7cba7b14 | 299 | static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |
8593fbc6 TG |
300 | size_t len) |
301 | { | |
302 | struct mtd_oob_ops ops; | |
b64d39d8 | 303 | int res; |
8593fbc6 TG |
304 | |
305 | ops.mode = MTD_OOB_RAW; | |
306 | ops.ooboffs = 0; | |
307 | ops.ooblen = mtd->oobsize; | |
8593fbc6 | 308 | |
b64d39d8 ML |
309 | |
310 | while (len > 0) { | |
311 | if (len <= mtd->writesize) { | |
312 | ops.oobbuf = buf + len; | |
313 | ops.datbuf = buf; | |
314 | ops.len = len; | |
903cd06c BN |
315 | res = mtd->read_oob(mtd, offs, &ops); |
316 | ||
317 | /* Ignore ECC errors when checking for BBM */ | |
318 | if (res != -EUCLEAN && res != -EBADMSG) | |
319 | return res; | |
320 | return 0; | |
b64d39d8 ML |
321 | } else { |
322 | ops.oobbuf = buf + mtd->writesize; | |
323 | ops.datbuf = buf; | |
324 | ops.len = mtd->writesize; | |
325 | res = mtd->read_oob(mtd, offs, &ops); | |
326 | ||
903cd06c BN |
327 | /* Ignore ECC errors when checking for BBM */ |
328 | if (res && res != -EUCLEAN && res != -EBADMSG) | |
b64d39d8 ML |
329 | return res; |
330 | } | |
331 | ||
332 | buf += mtd->oobsize + mtd->writesize; | |
333 | len -= mtd->writesize; | |
334 | } | |
335 | return 0; | |
8593fbc6 TG |
336 | } |
337 | ||
7cba7b14 SAS |
338 | static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |
339 | size_t len, struct nand_bbt_descr *td) | |
340 | { | |
341 | if (td->options & NAND_BBT_NO_OOB) | |
342 | return scan_read_raw_data(mtd, buf, offs, td); | |
343 | else | |
344 | return scan_read_raw_oob(mtd, buf, offs, len); | |
345 | } | |
346 | ||
8b6e50c9 | 347 | /* Scan write data with oob to flash */ |
8593fbc6 TG |
348 | static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len, |
349 | uint8_t *buf, uint8_t *oob) | |
350 | { | |
351 | struct mtd_oob_ops ops; | |
352 | ||
353 | ops.mode = MTD_OOB_PLACE; | |
354 | ops.ooboffs = 0; | |
355 | ops.ooblen = mtd->oobsize; | |
356 | ops.datbuf = buf; | |
357 | ops.oobbuf = oob; | |
358 | ops.len = len; | |
359 | ||
360 | return mtd->write_oob(mtd, offs, &ops); | |
361 | } | |
362 | ||
7cba7b14 SAS |
363 | static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td) |
364 | { | |
365 | u32 ver_offs = td->veroffs; | |
366 | ||
367 | if (!(td->options & NAND_BBT_NO_OOB)) | |
368 | ver_offs += mtd->writesize; | |
369 | return ver_offs; | |
370 | } | |
371 | ||
1da177e4 LT |
372 | /** |
373 | * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page | |
8b6e50c9 BN |
374 | * @mtd: MTD device structure |
375 | * @buf: temporary buffer | |
376 | * @td: descriptor for the bad block table | |
377 | * @md: descriptor for the bad block table mirror | |
1da177e4 | 378 | * |
8b6e50c9 BN |
379 | * Read the bad block table(s) for all chips starting at a given page. We |
380 | * assume that the bbt bits are in consecutive order. | |
381 | */ | |
8593fbc6 TG |
382 | static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf, |
383 | struct nand_bbt_descr *td, struct nand_bbt_descr *md) | |
1da177e4 LT |
384 | { |
385 | struct nand_chip *this = mtd->priv; | |
386 | ||
61b03bd7 | 387 | /* Read the primary version, if available */ |
1da177e4 | 388 | if (td->options & NAND_BBT_VERSION) { |
69423d99 | 389 | scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift, |
7cba7b14 SAS |
390 | mtd->writesize, td); |
391 | td->version[0] = buf[bbt_get_ver_offs(mtd, td)]; | |
8593fbc6 TG |
392 | printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", |
393 | td->pages[0], td->version[0]); | |
1da177e4 LT |
394 | } |
395 | ||
61b03bd7 | 396 | /* Read the mirror version, if available */ |
1da177e4 | 397 | if (md && (md->options & NAND_BBT_VERSION)) { |
69423d99 | 398 | scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift, |
7cba7b14 SAS |
399 | mtd->writesize, td); |
400 | md->version[0] = buf[bbt_get_ver_offs(mtd, md)]; | |
8593fbc6 TG |
401 | printk(KERN_DEBUG "Bad block table at page %d, version 0x%02X\n", |
402 | md->pages[0], md->version[0]); | |
1da177e4 | 403 | } |
1da177e4 LT |
404 | return 1; |
405 | } | |
406 | ||
8b6e50c9 | 407 | /* Scan a given block full */ |
8593fbc6 TG |
408 | static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd, |
409 | loff_t offs, uint8_t *buf, size_t readlen, | |
410 | int scanlen, int len) | |
411 | { | |
412 | int ret, j; | |
413 | ||
7cba7b14 | 414 | ret = scan_read_raw_oob(mtd, buf, offs, readlen); |
8593fbc6 TG |
415 | if (ret) |
416 | return ret; | |
417 | ||
418 | for (j = 0; j < len; j++, buf += scanlen) { | |
419 | if (check_pattern(buf, scanlen, mtd->writesize, bd)) | |
420 | return 1; | |
421 | } | |
422 | return 0; | |
423 | } | |
424 | ||
8b6e50c9 | 425 | /* Scan a given block partially */ |
8593fbc6 TG |
426 | static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd, |
427 | loff_t offs, uint8_t *buf, int len) | |
428 | { | |
429 | struct mtd_oob_ops ops; | |
430 | int j, ret; | |
431 | ||
8593fbc6 TG |
432 | ops.ooblen = mtd->oobsize; |
433 | ops.oobbuf = buf; | |
434 | ops.ooboffs = 0; | |
435 | ops.datbuf = NULL; | |
436 | ops.mode = MTD_OOB_PLACE; | |
437 | ||
438 | for (j = 0; j < len; j++) { | |
439 | /* | |
8b6e50c9 BN |
440 | * Read the full oob until read_oob is fixed to handle single |
441 | * byte reads for 16 bit buswidth. | |
8593fbc6 TG |
442 | */ |
443 | ret = mtd->read_oob(mtd, offs, &ops); | |
903cd06c BN |
444 | /* Ignore ECC errors when checking for BBM */ |
445 | if (ret && ret != -EUCLEAN && ret != -EBADMSG) | |
8593fbc6 TG |
446 | return ret; |
447 | ||
448 | if (check_short_pattern(buf, bd)) | |
449 | return 1; | |
450 | ||
451 | offs += mtd->writesize; | |
452 | } | |
453 | return 0; | |
454 | } | |
455 | ||
1da177e4 LT |
456 | /** |
457 | * create_bbt - [GENERIC] Create a bad block table by scanning the device | |
8b6e50c9 BN |
458 | * @mtd: MTD device structure |
459 | * @buf: temporary buffer | |
460 | * @bd: descriptor for the good/bad block search pattern | |
461 | * @chip: create the table for a specific chip, -1 read all chips; applies only | |
462 | * if NAND_BBT_PERCHIP option is set | |
1da177e4 | 463 | * |
8b6e50c9 BN |
464 | * Create a bad block table by scanning the device for the given good/bad block |
465 | * identify pattern. | |
1da177e4 | 466 | */ |
8593fbc6 TG |
467 | static int create_bbt(struct mtd_info *mtd, uint8_t *buf, |
468 | struct nand_bbt_descr *bd, int chip) | |
1da177e4 LT |
469 | { |
470 | struct nand_chip *this = mtd->priv; | |
8593fbc6 | 471 | int i, numblocks, len, scanlen; |
1da177e4 LT |
472 | int startblock; |
473 | loff_t from; | |
8593fbc6 | 474 | size_t readlen; |
1da177e4 | 475 | |
e0c7d767 | 476 | printk(KERN_INFO "Scanning device for bad blocks\n"); |
1da177e4 LT |
477 | |
478 | if (bd->options & NAND_BBT_SCANALLPAGES) | |
479 | len = 1 << (this->bbt_erase_shift - this->page_shift); | |
58373ff0 BN |
480 | else if (bd->options & NAND_BBT_SCAN2NDPAGE) |
481 | len = 2; | |
482 | else | |
483 | len = 1; | |
171650af AB |
484 | |
485 | if (!(bd->options & NAND_BBT_SCANEMPTY)) { | |
486 | /* We need only read few bytes from the OOB area */ | |
8593fbc6 | 487 | scanlen = 0; |
eeada24d AB |
488 | readlen = bd->len; |
489 | } else { | |
171650af | 490 | /* Full page content should be read */ |
28318776 JE |
491 | scanlen = mtd->writesize + mtd->oobsize; |
492 | readlen = len * mtd->writesize; | |
eeada24d | 493 | } |
1da177e4 LT |
494 | |
495 | if (chip == -1) { | |
8b6e50c9 BN |
496 | /* |
497 | * Note that numblocks is 2 * (real numblocks) here, see i+=2 | |
498 | * below as it makes shifting and masking less painful | |
499 | */ | |
1da177e4 LT |
500 | numblocks = mtd->size >> (this->bbt_erase_shift - 1); |
501 | startblock = 0; | |
502 | from = 0; | |
503 | } else { | |
504 | if (chip >= this->numchips) { | |
e0c7d767 DW |
505 | printk(KERN_WARNING "create_bbt(): chipnr (%d) > available chips (%d)\n", |
506 | chip + 1, this->numchips); | |
171650af | 507 | return -EINVAL; |
1da177e4 LT |
508 | } |
509 | numblocks = this->chipsize >> (this->bbt_erase_shift - 1); | |
510 | startblock = chip * numblocks; | |
511 | numblocks += startblock; | |
69423d99 | 512 | from = (loff_t)startblock << (this->bbt_erase_shift - 1); |
1da177e4 | 513 | } |
61b03bd7 | 514 | |
5fb1549d | 515 | if (this->bbt_options & NAND_BBT_SCANLASTPAGE) |
b60b08b0 KC |
516 | from += mtd->erasesize - (mtd->writesize * len); |
517 | ||
1da177e4 | 518 | for (i = startblock; i < numblocks;) { |
eeada24d | 519 | int ret; |
61b03bd7 | 520 | |
7cba7b14 SAS |
521 | BUG_ON(bd->options & NAND_BBT_NO_OOB); |
522 | ||
8593fbc6 TG |
523 | if (bd->options & NAND_BBT_SCANALLPAGES) |
524 | ret = scan_block_full(mtd, bd, from, buf, readlen, | |
525 | scanlen, len); | |
526 | else | |
527 | ret = scan_block_fast(mtd, bd, from, buf, len); | |
528 | ||
529 | if (ret < 0) | |
530 | return ret; | |
531 | ||
532 | if (ret) { | |
533 | this->bbt[i >> 3] |= 0x03 << (i & 0x6); | |
69423d99 AH |
534 | printk(KERN_WARNING "Bad eraseblock %d at 0x%012llx\n", |
535 | i >> 1, (unsigned long long)from); | |
f1a28c02 | 536 | mtd->ecc_stats.badblocks++; |
1da177e4 | 537 | } |
8593fbc6 | 538 | |
1da177e4 LT |
539 | i += 2; |
540 | from += (1 << this->bbt_erase_shift); | |
541 | } | |
eeada24d | 542 | return 0; |
1da177e4 LT |
543 | } |
544 | ||
545 | /** | |
546 | * search_bbt - [GENERIC] scan the device for a specific bad block table | |
8b6e50c9 BN |
547 | * @mtd: MTD device structure |
548 | * @buf: temporary buffer | |
549 | * @td: descriptor for the bad block table | |
1da177e4 | 550 | * |
8b6e50c9 BN |
551 | * Read the bad block table by searching for a given ident pattern. Search is |
552 | * preformed either from the beginning up or from the end of the device | |
553 | * downwards. The search starts always at the start of a block. If the option | |
554 | * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains | |
555 | * the bad block information of this chip. This is necessary to provide support | |
556 | * for certain DOC devices. | |
1da177e4 | 557 | * |
8b6e50c9 | 558 | * The bbt ident pattern resides in the oob area of the first page in a block. |
1da177e4 | 559 | */ |
e0c7d767 | 560 | static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td) |
1da177e4 LT |
561 | { |
562 | struct nand_chip *this = mtd->priv; | |
563 | int i, chips; | |
564 | int bits, startblock, block, dir; | |
28318776 | 565 | int scanlen = mtd->writesize + mtd->oobsize; |
1da177e4 | 566 | int bbtblocks; |
8593fbc6 | 567 | int blocktopage = this->bbt_erase_shift - this->page_shift; |
1da177e4 | 568 | |
8b6e50c9 | 569 | /* Search direction top -> down? */ |
1da177e4 | 570 | if (td->options & NAND_BBT_LASTBLOCK) { |
e0c7d767 | 571 | startblock = (mtd->size >> this->bbt_erase_shift) - 1; |
1da177e4 LT |
572 | dir = -1; |
573 | } else { | |
61b03bd7 | 574 | startblock = 0; |
1da177e4 | 575 | dir = 1; |
61b03bd7 TG |
576 | } |
577 | ||
8b6e50c9 | 578 | /* Do we have a bbt per chip? */ |
1da177e4 LT |
579 | if (td->options & NAND_BBT_PERCHIP) { |
580 | chips = this->numchips; | |
581 | bbtblocks = this->chipsize >> this->bbt_erase_shift; | |
582 | startblock &= bbtblocks - 1; | |
583 | } else { | |
584 | chips = 1; | |
585 | bbtblocks = mtd->size >> this->bbt_erase_shift; | |
586 | } | |
61b03bd7 | 587 | |
1da177e4 LT |
588 | /* Number of bits for each erase block in the bbt */ |
589 | bits = td->options & NAND_BBT_NRBITS_MSK; | |
61b03bd7 | 590 | |
1da177e4 LT |
591 | for (i = 0; i < chips; i++) { |
592 | /* Reset version information */ | |
61b03bd7 | 593 | td->version[i] = 0; |
1da177e4 LT |
594 | td->pages[i] = -1; |
595 | /* Scan the maximum number of blocks */ | |
596 | for (block = 0; block < td->maxblocks; block++) { | |
8593fbc6 | 597 | |
1da177e4 | 598 | int actblock = startblock + dir * block; |
69423d99 | 599 | loff_t offs = (loff_t)actblock << this->bbt_erase_shift; |
8593fbc6 | 600 | |
1da177e4 | 601 | /* Read first page */ |
7cba7b14 | 602 | scan_read_raw(mtd, buf, offs, mtd->writesize, td); |
28318776 | 603 | if (!check_pattern(buf, scanlen, mtd->writesize, td)) { |
8593fbc6 | 604 | td->pages[i] = actblock << blocktopage; |
1da177e4 | 605 | if (td->options & NAND_BBT_VERSION) { |
7cba7b14 SAS |
606 | offs = bbt_get_ver_offs(mtd, td); |
607 | td->version[i] = buf[offs]; | |
1da177e4 LT |
608 | } |
609 | break; | |
610 | } | |
611 | } | |
612 | startblock += this->chipsize >> this->bbt_erase_shift; | |
613 | } | |
614 | /* Check, if we found a bbt for each requested chip */ | |
615 | for (i = 0; i < chips; i++) { | |
616 | if (td->pages[i] == -1) | |
e0c7d767 | 617 | printk(KERN_WARNING "Bad block table not found for chip %d\n", i); |
1da177e4 | 618 | else |
e0c7d767 DW |
619 | printk(KERN_DEBUG "Bad block table found at page %d, version 0x%02X\n", td->pages[i], |
620 | td->version[i]); | |
1da177e4 | 621 | } |
61b03bd7 | 622 | return 0; |
1da177e4 LT |
623 | } |
624 | ||
625 | /** | |
626 | * search_read_bbts - [GENERIC] scan the device for bad block table(s) | |
8b6e50c9 BN |
627 | * @mtd: MTD device structure |
628 | * @buf: temporary buffer | |
629 | * @td: descriptor for the bad block table | |
630 | * @md: descriptor for the bad block table mirror | |
1da177e4 | 631 | * |
8b6e50c9 BN |
632 | * Search and read the bad block table(s). |
633 | */ | |
e0c7d767 | 634 | static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md) |
1da177e4 LT |
635 | { |
636 | /* Search the primary table */ | |
e0c7d767 | 637 | search_bbt(mtd, buf, td); |
61b03bd7 | 638 | |
1da177e4 LT |
639 | /* Search the mirror table */ |
640 | if (md) | |
e0c7d767 | 641 | search_bbt(mtd, buf, md); |
61b03bd7 | 642 | |
1da177e4 | 643 | /* Force result check */ |
61b03bd7 | 644 | return 1; |
1da177e4 | 645 | } |
1da177e4 | 646 | |
61b03bd7 | 647 | /** |
1da177e4 | 648 | * write_bbt - [GENERIC] (Re)write the bad block table |
8b6e50c9 BN |
649 | * @mtd: MTD device structure |
650 | * @buf: temporary buffer | |
651 | * @td: descriptor for the bad block table | |
652 | * @md: descriptor for the bad block table mirror | |
653 | * @chipsel: selector for a specific chip, -1 for all | |
1da177e4 | 654 | * |
8b6e50c9 BN |
655 | * (Re)write the bad block table. |
656 | */ | |
e0c7d767 | 657 | static int write_bbt(struct mtd_info *mtd, uint8_t *buf, |
9223a456 TG |
658 | struct nand_bbt_descr *td, struct nand_bbt_descr *md, |
659 | int chipsel) | |
1da177e4 LT |
660 | { |
661 | struct nand_chip *this = mtd->priv; | |
1da177e4 LT |
662 | struct erase_info einfo; |
663 | int i, j, res, chip = 0; | |
664 | int bits, startblock, dir, page, offs, numblocks, sft, sftmsk; | |
9223a456 | 665 | int nrchips, bbtoffs, pageoffs, ooboffs; |
1da177e4 LT |
666 | uint8_t msk[4]; |
667 | uint8_t rcode = td->reserved_block_code; | |
8593fbc6 | 668 | size_t retlen, len = 0; |
1da177e4 | 669 | loff_t to; |
8593fbc6 TG |
670 | struct mtd_oob_ops ops; |
671 | ||
672 | ops.ooblen = mtd->oobsize; | |
673 | ops.ooboffs = 0; | |
674 | ops.datbuf = NULL; | |
675 | ops.mode = MTD_OOB_PLACE; | |
1da177e4 LT |
676 | |
677 | if (!rcode) | |
678 | rcode = 0xff; | |
8b6e50c9 | 679 | /* Write bad block table per chip rather than per device? */ |
1da177e4 | 680 | if (td->options & NAND_BBT_PERCHIP) { |
e0c7d767 | 681 | numblocks = (int)(this->chipsize >> this->bbt_erase_shift); |
8b6e50c9 | 682 | /* Full device write or specific chip? */ |
1da177e4 LT |
683 | if (chipsel == -1) { |
684 | nrchips = this->numchips; | |
685 | } else { | |
686 | nrchips = chipsel + 1; | |
687 | chip = chipsel; | |
688 | } | |
689 | } else { | |
e0c7d767 | 690 | numblocks = (int)(mtd->size >> this->bbt_erase_shift); |
1da177e4 | 691 | nrchips = 1; |
61b03bd7 TG |
692 | } |
693 | ||
1da177e4 LT |
694 | /* Loop through the chips */ |
695 | for (; chip < nrchips; chip++) { | |
8b6e50c9 BN |
696 | /* |
697 | * There was already a version of the table, reuse the page | |
61b03bd7 | 698 | * This applies for absolute placement too, as we have the |
1da177e4 LT |
699 | * page nr. in td->pages. |
700 | */ | |
701 | if (td->pages[chip] != -1) { | |
702 | page = td->pages[chip]; | |
703 | goto write; | |
61b03bd7 | 704 | } |
1da177e4 | 705 | |
8b6e50c9 BN |
706 | /* |
707 | * Automatic placement of the bad block table. Search direction | |
708 | * top -> down? | |
709 | */ | |
1da177e4 LT |
710 | if (td->options & NAND_BBT_LASTBLOCK) { |
711 | startblock = numblocks * (chip + 1) - 1; | |
712 | dir = -1; | |
713 | } else { | |
714 | startblock = chip * numblocks; | |
715 | dir = 1; | |
61b03bd7 | 716 | } |
1da177e4 LT |
717 | |
718 | for (i = 0; i < td->maxblocks; i++) { | |
719 | int block = startblock + dir * i; | |
720 | /* Check, if the block is bad */ | |
9223a456 TG |
721 | switch ((this->bbt[block >> 2] >> |
722 | (2 * (block & 0x03))) & 0x03) { | |
1da177e4 LT |
723 | case 0x01: |
724 | case 0x03: | |
725 | continue; | |
726 | } | |
9223a456 TG |
727 | page = block << |
728 | (this->bbt_erase_shift - this->page_shift); | |
1da177e4 LT |
729 | /* Check, if the block is used by the mirror table */ |
730 | if (!md || md->pages[chip] != page) | |
731 | goto write; | |
732 | } | |
e0c7d767 | 733 | printk(KERN_ERR "No space left to write bad block table\n"); |
1da177e4 | 734 | return -ENOSPC; |
e0c7d767 | 735 | write: |
1da177e4 LT |
736 | |
737 | /* Set up shift count and masks for the flash table */ | |
738 | bits = td->options & NAND_BBT_NRBITS_MSK; | |
9223a456 | 739 | msk[2] = ~rcode; |
1da177e4 | 740 | switch (bits) { |
9223a456 TG |
741 | case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; |
742 | msk[3] = 0x01; | |
743 | break; | |
744 | case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; | |
745 | msk[3] = 0x03; | |
746 | break; | |
747 | case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; | |
748 | msk[3] = 0x0f; | |
749 | break; | |
750 | case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; | |
751 | msk[3] = 0xff; | |
752 | break; | |
1da177e4 LT |
753 | default: return -EINVAL; |
754 | } | |
61b03bd7 | 755 | |
1da177e4 | 756 | bbtoffs = chip * (numblocks >> 2); |
61b03bd7 | 757 | |
1da177e4 LT |
758 | to = ((loff_t) page) << this->page_shift; |
759 | ||
8b6e50c9 | 760 | /* Must we save the block contents? */ |
1da177e4 LT |
761 | if (td->options & NAND_BBT_SAVECONTENT) { |
762 | /* Make it block aligned */ | |
763 | to &= ~((loff_t) ((1 << this->bbt_erase_shift) - 1)); | |
764 | len = 1 << this->bbt_erase_shift; | |
9223a456 | 765 | res = mtd->read(mtd, to, len, &retlen, buf); |
1da177e4 LT |
766 | if (res < 0) { |
767 | if (retlen != len) { | |
9223a456 TG |
768 | printk(KERN_INFO "nand_bbt: Error " |
769 | "reading block for writing " | |
770 | "the bad block table\n"); | |
1da177e4 LT |
771 | return res; |
772 | } | |
9223a456 TG |
773 | printk(KERN_WARNING "nand_bbt: ECC error " |
774 | "while reading block for writing " | |
775 | "bad block table\n"); | |
1da177e4 | 776 | } |
9223a456 | 777 | /* Read oob data */ |
7014568b | 778 | ops.ooblen = (len >> this->page_shift) * mtd->oobsize; |
8593fbc6 TG |
779 | ops.oobbuf = &buf[len]; |
780 | res = mtd->read_oob(mtd, to + mtd->writesize, &ops); | |
7014568b | 781 | if (res < 0 || ops.oobretlen != ops.ooblen) |
9223a456 TG |
782 | goto outerr; |
783 | ||
1da177e4 LT |
784 | /* Calc the byte offset in the buffer */ |
785 | pageoffs = page - (int)(to >> this->page_shift); | |
786 | offs = pageoffs << this->page_shift; | |
787 | /* Preset the bbt area with 0xff */ | |
e0c7d767 | 788 | memset(&buf[offs], 0xff, (size_t) (numblocks >> sft)); |
9223a456 TG |
789 | ooboffs = len + (pageoffs * mtd->oobsize); |
790 | ||
7cba7b14 SAS |
791 | } else if (td->options & NAND_BBT_NO_OOB) { |
792 | ooboffs = 0; | |
793 | offs = td->len; | |
8b6e50c9 | 794 | /* The version byte */ |
7cba7b14 SAS |
795 | if (td->options & NAND_BBT_VERSION) |
796 | offs++; | |
797 | /* Calc length */ | |
798 | len = (size_t) (numblocks >> sft); | |
799 | len += offs; | |
8b6e50c9 | 800 | /* Make it page aligned! */ |
7cba7b14 SAS |
801 | len = ALIGN(len, mtd->writesize); |
802 | /* Preset the buffer with 0xff */ | |
803 | memset(buf, 0xff, len); | |
804 | /* Pattern is located at the begin of first page */ | |
805 | memcpy(buf, td->pattern, td->len); | |
1da177e4 LT |
806 | } else { |
807 | /* Calc length */ | |
808 | len = (size_t) (numblocks >> sft); | |
8b6e50c9 | 809 | /* Make it page aligned! */ |
cda32091 | 810 | len = ALIGN(len, mtd->writesize); |
1da177e4 | 811 | /* Preset the buffer with 0xff */ |
9223a456 TG |
812 | memset(buf, 0xff, len + |
813 | (len >> this->page_shift)* mtd->oobsize); | |
1da177e4 | 814 | offs = 0; |
9223a456 | 815 | ooboffs = len; |
1da177e4 | 816 | /* Pattern is located in oob area of first page */ |
9223a456 | 817 | memcpy(&buf[ooboffs + td->offs], td->pattern, td->len); |
1da177e4 | 818 | } |
61b03bd7 | 819 | |
9223a456 TG |
820 | if (td->options & NAND_BBT_VERSION) |
821 | buf[ooboffs + td->veroffs] = td->version[chip]; | |
822 | ||
8b6e50c9 | 823 | /* Walk through the memory table */ |
e0c7d767 | 824 | for (i = 0; i < numblocks;) { |
1da177e4 LT |
825 | uint8_t dat; |
826 | dat = this->bbt[bbtoffs + (i >> 2)]; | |
e0c7d767 | 827 | for (j = 0; j < 4; j++, i++) { |
1da177e4 | 828 | int sftcnt = (i << (3 - sft)) & sftmsk; |
8b6e50c9 | 829 | /* Do not store the reserved bbt blocks! */ |
9223a456 TG |
830 | buf[offs + (i >> sft)] &= |
831 | ~(msk[dat & 0x03] << sftcnt); | |
1da177e4 LT |
832 | dat >>= 2; |
833 | } | |
834 | } | |
61b03bd7 | 835 | |
e0c7d767 | 836 | memset(&einfo, 0, sizeof(einfo)); |
1da177e4 | 837 | einfo.mtd = mtd; |
69423d99 | 838 | einfo.addr = to; |
1da177e4 | 839 | einfo.len = 1 << this->bbt_erase_shift; |
e0c7d767 | 840 | res = nand_erase_nand(mtd, &einfo, 1); |
9223a456 TG |
841 | if (res < 0) |
842 | goto outerr; | |
61b03bd7 | 843 | |
7cba7b14 SAS |
844 | res = scan_write_bbt(mtd, to, len, buf, |
845 | td->options & NAND_BBT_NO_OOB ? NULL : | |
846 | &buf[len]); | |
9223a456 TG |
847 | if (res < 0) |
848 | goto outerr; | |
849 | ||
69423d99 AH |
850 | printk(KERN_DEBUG "Bad block table written to 0x%012llx, version " |
851 | "0x%02X\n", (unsigned long long)to, td->version[chip]); | |
61b03bd7 | 852 | |
1da177e4 LT |
853 | /* Mark it as used */ |
854 | td->pages[chip] = page; | |
61b03bd7 | 855 | } |
1da177e4 | 856 | return 0; |
9223a456 TG |
857 | |
858 | outerr: | |
859 | printk(KERN_WARNING | |
860 | "nand_bbt: Error while writing bad block table %d\n", res); | |
861 | return res; | |
1da177e4 LT |
862 | } |
863 | ||
864 | /** | |
865 | * nand_memory_bbt - [GENERIC] create a memory based bad block table | |
8b6e50c9 BN |
866 | * @mtd: MTD device structure |
867 | * @bd: descriptor for the good/bad block search pattern | |
1da177e4 | 868 | * |
8b6e50c9 BN |
869 | * The function creates a memory based bbt by scanning the device for |
870 | * manufacturer / software marked good / bad blocks. | |
871 | */ | |
e0c7d767 | 872 | static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) |
1da177e4 LT |
873 | { |
874 | struct nand_chip *this = mtd->priv; | |
875 | ||
171650af | 876 | bd->options &= ~NAND_BBT_SCANEMPTY; |
4bf63fcb | 877 | return create_bbt(mtd, this->buffers->databuf, bd, -1); |
1da177e4 LT |
878 | } |
879 | ||
880 | /** | |
e0c7d767 | 881 | * check_create - [GENERIC] create and write bbt(s) if necessary |
8b6e50c9 BN |
882 | * @mtd: MTD device structure |
883 | * @buf: temporary buffer | |
884 | * @bd: descriptor for the good/bad block search pattern | |
1da177e4 | 885 | * |
8b6e50c9 BN |
886 | * The function checks the results of the previous call to read_bbt and creates |
887 | * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found | |
888 | * for the chip/device. Update is necessary if one of the tables is missing or | |
889 | * the version nr. of one table is less than the other. | |
890 | */ | |
e0c7d767 | 891 | static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd) |
1da177e4 LT |
892 | { |
893 | int i, chips, writeops, chipsel, res; | |
894 | struct nand_chip *this = mtd->priv; | |
895 | struct nand_bbt_descr *td = this->bbt_td; | |
896 | struct nand_bbt_descr *md = this->bbt_md; | |
897 | struct nand_bbt_descr *rd, *rd2; | |
898 | ||
8b6e50c9 | 899 | /* Do we have a bbt per chip? */ |
61b03bd7 | 900 | if (td->options & NAND_BBT_PERCHIP) |
1da177e4 | 901 | chips = this->numchips; |
61b03bd7 | 902 | else |
1da177e4 | 903 | chips = 1; |
61b03bd7 | 904 | |
1da177e4 LT |
905 | for (i = 0; i < chips; i++) { |
906 | writeops = 0; | |
907 | rd = NULL; | |
908 | rd2 = NULL; | |
8b6e50c9 | 909 | /* Per chip or per device? */ |
1da177e4 | 910 | chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1; |
8b6e50c9 | 911 | /* Mirrored table available? */ |
1da177e4 LT |
912 | if (md) { |
913 | if (td->pages[i] == -1 && md->pages[i] == -1) { | |
914 | writeops = 0x03; | |
915 | goto create; | |
916 | } | |
917 | ||
918 | if (td->pages[i] == -1) { | |
61b03bd7 | 919 | rd = md; |
1da177e4 LT |
920 | td->version[i] = md->version[i]; |
921 | writeops = 1; | |
922 | goto writecheck; | |
923 | } | |
924 | ||
925 | if (md->pages[i] == -1) { | |
926 | rd = td; | |
927 | md->version[i] = td->version[i]; | |
928 | writeops = 2; | |
929 | goto writecheck; | |
930 | } | |
931 | ||
932 | if (td->version[i] == md->version[i]) { | |
933 | rd = td; | |
934 | if (!(td->options & NAND_BBT_VERSION)) | |
935 | rd2 = md; | |
936 | goto writecheck; | |
61b03bd7 | 937 | } |
1da177e4 LT |
938 | |
939 | if (((int8_t) (td->version[i] - md->version[i])) > 0) { | |
940 | rd = td; | |
941 | md->version[i] = td->version[i]; | |
942 | writeops = 2; | |
943 | } else { | |
944 | rd = md; | |
945 | td->version[i] = md->version[i]; | |
946 | writeops = 1; | |
947 | } | |
948 | ||
949 | goto writecheck; | |
950 | ||
951 | } else { | |
952 | if (td->pages[i] == -1) { | |
953 | writeops = 0x01; | |
954 | goto create; | |
955 | } | |
956 | rd = td; | |
957 | goto writecheck; | |
958 | } | |
e0c7d767 | 959 | create: |
8b6e50c9 | 960 | /* Create the bad block table by scanning the device? */ |
1da177e4 | 961 | if (!(td->options & NAND_BBT_CREATE)) |
61b03bd7 TG |
962 | continue; |
963 | ||
1da177e4 | 964 | /* Create the table in memory by scanning the chip(s) */ |
53d5d888 | 965 | if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY)) |
453281a9 | 966 | create_bbt(mtd, buf, bd, chipsel); |
61b03bd7 | 967 | |
1da177e4 LT |
968 | td->version[i] = 1; |
969 | if (md) | |
61b03bd7 | 970 | md->version[i] = 1; |
e0c7d767 | 971 | writecheck: |
8b6e50c9 | 972 | /* Read back first? */ |
1da177e4 | 973 | if (rd) |
e0c7d767 | 974 | read_abs_bbt(mtd, buf, rd, chipsel); |
8b6e50c9 | 975 | /* If they weren't versioned, read both */ |
1da177e4 | 976 | if (rd2) |
e0c7d767 | 977 | read_abs_bbt(mtd, buf, rd2, chipsel); |
1da177e4 | 978 | |
8b6e50c9 | 979 | /* Write the bad block table to the device? */ |
1da177e4 | 980 | if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { |
e0c7d767 | 981 | res = write_bbt(mtd, buf, td, md, chipsel); |
1da177e4 LT |
982 | if (res < 0) |
983 | return res; | |
984 | } | |
61b03bd7 | 985 | |
8b6e50c9 | 986 | /* Write the mirror bad block table to the device? */ |
1da177e4 | 987 | if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) { |
e0c7d767 | 988 | res = write_bbt(mtd, buf, md, td, chipsel); |
1da177e4 LT |
989 | if (res < 0) |
990 | return res; | |
991 | } | |
992 | } | |
61b03bd7 | 993 | return 0; |
1da177e4 LT |
994 | } |
995 | ||
996 | /** | |
61b03bd7 | 997 | * mark_bbt_regions - [GENERIC] mark the bad block table regions |
8b6e50c9 BN |
998 | * @mtd: MTD device structure |
999 | * @td: bad block table descriptor | |
1da177e4 | 1000 | * |
8b6e50c9 BN |
1001 | * The bad block table regions are marked as "bad" to prevent accidental |
1002 | * erasures / writes. The regions are identified by the mark 0x02. | |
1003 | */ | |
e0c7d767 | 1004 | static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) |
1da177e4 LT |
1005 | { |
1006 | struct nand_chip *this = mtd->priv; | |
1007 | int i, j, chips, block, nrblocks, update; | |
1008 | uint8_t oldval, newval; | |
1009 | ||
8b6e50c9 | 1010 | /* Do we have a bbt per chip? */ |
1da177e4 LT |
1011 | if (td->options & NAND_BBT_PERCHIP) { |
1012 | chips = this->numchips; | |
1013 | nrblocks = (int)(this->chipsize >> this->bbt_erase_shift); | |
1014 | } else { | |
1015 | chips = 1; | |
1016 | nrblocks = (int)(mtd->size >> this->bbt_erase_shift); | |
61b03bd7 TG |
1017 | } |
1018 | ||
1da177e4 LT |
1019 | for (i = 0; i < chips; i++) { |
1020 | if ((td->options & NAND_BBT_ABSPAGE) || | |
1021 | !(td->options & NAND_BBT_WRITE)) { | |
e0c7d767 DW |
1022 | if (td->pages[i] == -1) |
1023 | continue; | |
1da177e4 | 1024 | block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift); |
61b03bd7 | 1025 | block <<= 1; |
1da177e4 LT |
1026 | oldval = this->bbt[(block >> 3)]; |
1027 | newval = oldval | (0x2 << (block & 0x06)); | |
1028 | this->bbt[(block >> 3)] = newval; | |
1029 | if ((oldval != newval) && td->reserved_block_code) | |
69423d99 | 1030 | nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1)); |
1da177e4 LT |
1031 | continue; |
1032 | } | |
1033 | update = 0; | |
1034 | if (td->options & NAND_BBT_LASTBLOCK) | |
1035 | block = ((i + 1) * nrblocks) - td->maxblocks; | |
61b03bd7 | 1036 | else |
1da177e4 | 1037 | block = i * nrblocks; |
61b03bd7 | 1038 | block <<= 1; |
1da177e4 LT |
1039 | for (j = 0; j < td->maxblocks; j++) { |
1040 | oldval = this->bbt[(block >> 3)]; | |
1041 | newval = oldval | (0x2 << (block & 0x06)); | |
1042 | this->bbt[(block >> 3)] = newval; | |
e0c7d767 DW |
1043 | if (oldval != newval) |
1044 | update = 1; | |
1da177e4 | 1045 | block += 2; |
61b03bd7 | 1046 | } |
8b6e50c9 BN |
1047 | /* |
1048 | * If we want reserved blocks to be recorded to flash, and some | |
1049 | * new ones have been marked, then we need to update the stored | |
1050 | * bbts. This should only happen once. | |
1051 | */ | |
1da177e4 | 1052 | if (update && td->reserved_block_code) |
69423d99 | 1053 | nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1)); |
1da177e4 LT |
1054 | } |
1055 | } | |
1056 | ||
7cba7b14 SAS |
1057 | /** |
1058 | * verify_bbt_descr - verify the bad block description | |
8b6e50c9 BN |
1059 | * @mtd: MTD device structure |
1060 | * @bd: the table to verify | |
7cba7b14 SAS |
1061 | * |
1062 | * This functions performs a few sanity checks on the bad block description | |
1063 | * table. | |
1064 | */ | |
1065 | static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd) | |
1066 | { | |
1067 | struct nand_chip *this = mtd->priv; | |
7912a5e7 SF |
1068 | u32 pattern_len; |
1069 | u32 bits; | |
7cba7b14 SAS |
1070 | u32 table_size; |
1071 | ||
1072 | if (!bd) | |
1073 | return; | |
7912a5e7 SF |
1074 | |
1075 | pattern_len = bd->len; | |
1076 | bits = bd->options & NAND_BBT_NRBITS_MSK; | |
1077 | ||
a40f7341 | 1078 | BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) && |
bb9ebd4e | 1079 | !(this->bbt_options & NAND_BBT_USE_FLASH)); |
7cba7b14 SAS |
1080 | BUG_ON(!bits); |
1081 | ||
1082 | if (bd->options & NAND_BBT_VERSION) | |
1083 | pattern_len++; | |
1084 | ||
1085 | if (bd->options & NAND_BBT_NO_OOB) { | |
bb9ebd4e | 1086 | BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH)); |
a40f7341 | 1087 | BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB)); |
7cba7b14 SAS |
1088 | BUG_ON(bd->offs); |
1089 | if (bd->options & NAND_BBT_VERSION) | |
1090 | BUG_ON(bd->veroffs != bd->len); | |
1091 | BUG_ON(bd->options & NAND_BBT_SAVECONTENT); | |
1092 | } | |
1093 | ||
1094 | if (bd->options & NAND_BBT_PERCHIP) | |
1095 | table_size = this->chipsize >> this->bbt_erase_shift; | |
1096 | else | |
1097 | table_size = mtd->size >> this->bbt_erase_shift; | |
1098 | table_size >>= 3; | |
1099 | table_size *= bits; | |
1100 | if (bd->options & NAND_BBT_NO_OOB) | |
1101 | table_size += pattern_len; | |
1102 | BUG_ON(table_size > (1 << this->bbt_erase_shift)); | |
1103 | } | |
1104 | ||
1da177e4 LT |
1105 | /** |
1106 | * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s) | |
8b6e50c9 BN |
1107 | * @mtd: MTD device structure |
1108 | * @bd: descriptor for the good/bad block search pattern | |
1da177e4 | 1109 | * |
8b6e50c9 BN |
1110 | * The function checks, if a bad block table(s) is/are already available. If |
1111 | * not it scans the device for manufacturer marked good / bad blocks and writes | |
1112 | * the bad block table(s) to the selected place. | |
1da177e4 | 1113 | * |
8b6e50c9 BN |
1114 | * The bad block table memory is allocated here. It must be freed by calling |
1115 | * the nand_free_bbt function. | |
1116 | */ | |
e0c7d767 | 1117 | int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) |
1da177e4 LT |
1118 | { |
1119 | struct nand_chip *this = mtd->priv; | |
1120 | int len, res = 0; | |
1121 | uint8_t *buf; | |
1122 | struct nand_bbt_descr *td = this->bbt_td; | |
1123 | struct nand_bbt_descr *md = this->bbt_md; | |
1124 | ||
1125 | len = mtd->size >> (this->bbt_erase_shift + 2); | |
8b6e50c9 BN |
1126 | /* |
1127 | * Allocate memory (2bit per block) and clear the memory bad block | |
1128 | * table. | |
1129 | */ | |
95b93a0c | 1130 | this->bbt = kzalloc(len, GFP_KERNEL); |
0870066d | 1131 | if (!this->bbt) |
1da177e4 | 1132 | return -ENOMEM; |
1da177e4 | 1133 | |
8b6e50c9 BN |
1134 | /* |
1135 | * If no primary table decriptor is given, scan the device to build a | |
1136 | * memory based bad block table. | |
1da177e4 | 1137 | */ |
eeada24d AB |
1138 | if (!td) { |
1139 | if ((res = nand_memory_bbt(mtd, bd))) { | |
e0c7d767 DW |
1140 | printk(KERN_ERR "nand_bbt: Can't scan flash and build the RAM-based BBT\n"); |
1141 | kfree(this->bbt); | |
eeada24d AB |
1142 | this->bbt = NULL; |
1143 | } | |
1144 | return res; | |
1145 | } | |
7cba7b14 SAS |
1146 | verify_bbt_descr(mtd, td); |
1147 | verify_bbt_descr(mtd, md); | |
1da177e4 LT |
1148 | |
1149 | /* Allocate a temporary buffer for one eraseblock incl. oob */ | |
1150 | len = (1 << this->bbt_erase_shift); | |
1151 | len += (len >> this->page_shift) * mtd->oobsize; | |
c3f8abf4 | 1152 | buf = vmalloc(len); |
1da177e4 | 1153 | if (!buf) { |
e0c7d767 | 1154 | kfree(this->bbt); |
1da177e4 LT |
1155 | this->bbt = NULL; |
1156 | return -ENOMEM; | |
1157 | } | |
61b03bd7 | 1158 | |
8b6e50c9 | 1159 | /* Is the bbt at a given page? */ |
1da177e4 | 1160 | if (td->options & NAND_BBT_ABSPAGE) { |
e0c7d767 | 1161 | res = read_abs_bbts(mtd, buf, td, md); |
61b03bd7 | 1162 | } else { |
1da177e4 | 1163 | /* Search the bad block table using a pattern in oob */ |
e0c7d767 | 1164 | res = search_read_bbts(mtd, buf, td, md); |
61b03bd7 | 1165 | } |
1da177e4 | 1166 | |
61b03bd7 | 1167 | if (res) |
e0c7d767 | 1168 | res = check_create(mtd, buf, bd); |
61b03bd7 | 1169 | |
1da177e4 | 1170 | /* Prevent the bbt regions from erasing / writing */ |
e0c7d767 | 1171 | mark_bbt_region(mtd, td); |
1da177e4 | 1172 | if (md) |
e0c7d767 | 1173 | mark_bbt_region(mtd, md); |
61b03bd7 | 1174 | |
e0c7d767 | 1175 | vfree(buf); |
1da177e4 LT |
1176 | return res; |
1177 | } | |
1178 | ||
1da177e4 | 1179 | /** |
61b03bd7 | 1180 | * nand_update_bbt - [NAND Interface] update bad block table(s) |
8b6e50c9 BN |
1181 | * @mtd: MTD device structure |
1182 | * @offs: the offset of the newly marked block | |
1da177e4 | 1183 | * |
8b6e50c9 BN |
1184 | * The function updates the bad block table(s). |
1185 | */ | |
e0c7d767 | 1186 | int nand_update_bbt(struct mtd_info *mtd, loff_t offs) |
1da177e4 LT |
1187 | { |
1188 | struct nand_chip *this = mtd->priv; | |
1189 | int len, res = 0, writeops = 0; | |
1190 | int chip, chipsel; | |
1191 | uint8_t *buf; | |
1192 | struct nand_bbt_descr *td = this->bbt_td; | |
1193 | struct nand_bbt_descr *md = this->bbt_md; | |
1194 | ||
1195 | if (!this->bbt || !td) | |
1196 | return -EINVAL; | |
1197 | ||
1da177e4 LT |
1198 | /* Allocate a temporary buffer for one eraseblock incl. oob */ |
1199 | len = (1 << this->bbt_erase_shift); | |
1200 | len += (len >> this->page_shift) * mtd->oobsize; | |
e0c7d767 | 1201 | buf = kmalloc(len, GFP_KERNEL); |
0870066d | 1202 | if (!buf) |
1da177e4 | 1203 | return -ENOMEM; |
61b03bd7 | 1204 | |
1da177e4 LT |
1205 | writeops = md != NULL ? 0x03 : 0x01; |
1206 | ||
8b6e50c9 | 1207 | /* Do we have a bbt per chip? */ |
1da177e4 | 1208 | if (td->options & NAND_BBT_PERCHIP) { |
e0c7d767 | 1209 | chip = (int)(offs >> this->chip_shift); |
1da177e4 LT |
1210 | chipsel = chip; |
1211 | } else { | |
1212 | chip = 0; | |
1213 | chipsel = -1; | |
1214 | } | |
1215 | ||
1216 | td->version[chip]++; | |
1217 | if (md) | |
61b03bd7 | 1218 | md->version[chip]++; |
1da177e4 | 1219 | |
8b6e50c9 | 1220 | /* Write the bad block table to the device? */ |
1da177e4 | 1221 | if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { |
e0c7d767 | 1222 | res = write_bbt(mtd, buf, td, md, chipsel); |
1da177e4 LT |
1223 | if (res < 0) |
1224 | goto out; | |
1225 | } | |
8b6e50c9 | 1226 | /* Write the mirror bad block table to the device? */ |
1da177e4 | 1227 | if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) { |
e0c7d767 | 1228 | res = write_bbt(mtd, buf, md, td, chipsel); |
1da177e4 LT |
1229 | } |
1230 | ||
e0c7d767 DW |
1231 | out: |
1232 | kfree(buf); | |
1da177e4 LT |
1233 | return res; |
1234 | } | |
1235 | ||
8b6e50c9 BN |
1236 | /* |
1237 | * Define some generic bad / good block scan pattern which are used | |
1238 | * while scanning a device for factory marked good / bad blocks. | |
1239 | */ | |
1da177e4 LT |
1240 | static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; |
1241 | ||
1da177e4 LT |
1242 | static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 }; |
1243 | ||
1244 | static struct nand_bbt_descr agand_flashbased = { | |
1245 | .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES, | |
1246 | .offs = 0x20, | |
1247 | .len = 6, | |
1248 | .pattern = scan_agand_pattern | |
1249 | }; | |
1250 | ||
7854d3f7 | 1251 | /* Generic flash bbt descriptors */ |
1da177e4 LT |
1252 | static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' }; |
1253 | static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' }; | |
1254 | ||
1255 | static struct nand_bbt_descr bbt_main_descr = { | |
61b03bd7 | 1256 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
1da177e4 LT |
1257 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP, |
1258 | .offs = 8, | |
1259 | .len = 4, | |
1260 | .veroffs = 12, | |
1261 | .maxblocks = 4, | |
1262 | .pattern = bbt_pattern | |
1263 | }; | |
1264 | ||
1265 | static struct nand_bbt_descr bbt_mirror_descr = { | |
61b03bd7 | 1266 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
1da177e4 LT |
1267 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP, |
1268 | .offs = 8, | |
1269 | .len = 4, | |
1270 | .veroffs = 12, | |
1271 | .maxblocks = 4, | |
1272 | .pattern = mirror_pattern | |
1273 | }; | |
1274 | ||
7cba7b14 SAS |
1275 | static struct nand_bbt_descr bbt_main_no_bbt_descr = { |
1276 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE | |
1277 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP | |
1278 | | NAND_BBT_NO_OOB, | |
1279 | .len = 4, | |
1280 | .veroffs = 4, | |
1281 | .maxblocks = 4, | |
1282 | .pattern = bbt_pattern | |
1283 | }; | |
1284 | ||
1285 | static struct nand_bbt_descr bbt_mirror_no_bbt_descr = { | |
1286 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE | |
1287 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP | |
1288 | | NAND_BBT_NO_OOB, | |
1289 | .len = 4, | |
1290 | .veroffs = 4, | |
1291 | .maxblocks = 4, | |
1292 | .pattern = mirror_pattern | |
1293 | }; | |
1294 | ||
58373ff0 | 1295 | /** |
7854d3f7 | 1296 | * nand_create_default_bbt_descr - [INTERN] Creates a BBT descriptor structure |
8b6e50c9 | 1297 | * @this: NAND chip to create descriptor for |
58373ff0 BN |
1298 | * |
1299 | * This function allocates and initializes a nand_bbt_descr for BBM detection | |
1300 | * based on the properties of "this". The new descriptor is stored in | |
1301 | * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when | |
1302 | * passed to this function. | |
58373ff0 BN |
1303 | */ |
1304 | static int nand_create_default_bbt_descr(struct nand_chip *this) | |
1305 | { | |
1306 | struct nand_bbt_descr *bd; | |
1307 | if (this->badblock_pattern) { | |
1308 | printk(KERN_WARNING "BBT descr already allocated; not replacing.\n"); | |
1309 | return -EINVAL; | |
1310 | } | |
1311 | bd = kzalloc(sizeof(*bd), GFP_KERNEL); | |
0870066d | 1312 | if (!bd) |
58373ff0 | 1313 | return -ENOMEM; |
5fb1549d | 1314 | bd->options = this->bbt_options; |
58373ff0 BN |
1315 | bd->offs = this->badblockpos; |
1316 | bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1; | |
1317 | bd->pattern = scan_ff_pattern; | |
1318 | bd->options |= NAND_BBT_DYNAMICSTRUCT; | |
1319 | this->badblock_pattern = bd; | |
1320 | return 0; | |
1321 | } | |
1322 | ||
1da177e4 | 1323 | /** |
61b03bd7 | 1324 | * nand_default_bbt - [NAND Interface] Select a default bad block table for the device |
8b6e50c9 | 1325 | * @mtd: MTD device structure |
1da177e4 | 1326 | * |
8b6e50c9 BN |
1327 | * This function selects the default bad block table support for the device and |
1328 | * calls the nand_scan_bbt function. | |
1329 | */ | |
e0c7d767 | 1330 | int nand_default_bbt(struct mtd_info *mtd) |
1da177e4 LT |
1331 | { |
1332 | struct nand_chip *this = mtd->priv; | |
61b03bd7 | 1333 | |
8b6e50c9 BN |
1334 | /* |
1335 | * Default for AG-AND. We must use a flash based bad block table as the | |
1336 | * devices have factory marked _good_ blocks. Erasing those blocks | |
1337 | * leads to loss of the good / bad information, so we _must_ store this | |
1338 | * information in a good / bad table during startup. | |
e0c7d767 | 1339 | */ |
1da177e4 LT |
1340 | if (this->options & NAND_IS_AND) { |
1341 | /* Use the default pattern descriptors */ | |
61b03bd7 | 1342 | if (!this->bbt_td) { |
1da177e4 LT |
1343 | this->bbt_td = &bbt_main_descr; |
1344 | this->bbt_md = &bbt_mirror_descr; | |
61b03bd7 | 1345 | } |
bb9ebd4e | 1346 | this->bbt_options |= NAND_BBT_USE_FLASH; |
e0c7d767 | 1347 | return nand_scan_bbt(mtd, &agand_flashbased); |
1da177e4 | 1348 | } |
61b03bd7 | 1349 | |
8b6e50c9 | 1350 | /* Is a flash based bad block table requested? */ |
bb9ebd4e | 1351 | if (this->bbt_options & NAND_BBT_USE_FLASH) { |
61b03bd7 TG |
1352 | /* Use the default pattern descriptors */ |
1353 | if (!this->bbt_td) { | |
a40f7341 | 1354 | if (this->bbt_options & NAND_BBT_NO_OOB) { |
7cba7b14 SAS |
1355 | this->bbt_td = &bbt_main_no_bbt_descr; |
1356 | this->bbt_md = &bbt_mirror_no_bbt_descr; | |
1357 | } else { | |
1358 | this->bbt_td = &bbt_main_descr; | |
1359 | this->bbt_md = &bbt_mirror_descr; | |
1360 | } | |
1da177e4 | 1361 | } |
1da177e4 LT |
1362 | } else { |
1363 | this->bbt_td = NULL; | |
1364 | this->bbt_md = NULL; | |
1da177e4 | 1365 | } |
a2f812df BN |
1366 | |
1367 | if (!this->badblock_pattern) | |
1368 | nand_create_default_bbt_descr(this); | |
1369 | ||
e0c7d767 | 1370 | return nand_scan_bbt(mtd, this->badblock_pattern); |
1da177e4 LT |
1371 | } |
1372 | ||
1373 | /** | |
61b03bd7 | 1374 | * nand_isbad_bbt - [NAND Interface] Check if a block is bad |
8b6e50c9 BN |
1375 | * @mtd: MTD device structure |
1376 | * @offs: offset in the device | |
1377 | * @allowbbt: allow access to bad block table region | |
1378 | */ | |
e0c7d767 | 1379 | int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) |
1da177e4 LT |
1380 | { |
1381 | struct nand_chip *this = mtd->priv; | |
1382 | int block; | |
e0c7d767 | 1383 | uint8_t res; |
61b03bd7 | 1384 | |
1da177e4 | 1385 | /* Get block number * 2 */ |
e0c7d767 | 1386 | block = (int)(offs >> (this->bbt_erase_shift - 1)); |
1da177e4 LT |
1387 | res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03; |
1388 | ||
e0c7d767 DW |
1389 | DEBUG(MTD_DEBUG_LEVEL2, "nand_isbad_bbt(): bbt info for offs 0x%08x: (block %d) 0x%02x\n", |
1390 | (unsigned int)offs, block >> 1, res); | |
1da177e4 LT |
1391 | |
1392 | switch ((int)res) { | |
e0c7d767 DW |
1393 | case 0x00: |
1394 | return 0; | |
1395 | case 0x01: | |
1396 | return 1; | |
1397 | case 0x02: | |
1398 | return allowbbt ? 0 : 1; | |
1da177e4 LT |
1399 | } |
1400 | return 1; | |
1401 | } | |
1402 | ||
e0c7d767 DW |
1403 | EXPORT_SYMBOL(nand_scan_bbt); |
1404 | EXPORT_SYMBOL(nand_default_bbt); |