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27 | * If one of the BBTs is out of date or does not exist it is (re)created.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 | 180 | { |
167a8d52 | 181 | int res, ret = 0, i, j, act = 0; |
1da177e4 LT |
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; |
596d7452 | 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); |
596d7452 | 192 | from = ((loff_t)page) << this->page_shift; |
61b03bd7 | 193 | |
1da177e4 | 194 | while (totlen) { |
596d7452 | 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 | 206 | if (res < 0) { |
167a8d52 BN |
207 | if (mtd_is_eccerr(res)) { |
208 | pr_info("nand_bbt: ECC error in BBT at " | |
209 | "0x%012llx\n", from & ~mtd->writesize); | |
210 | return res; | |
211 | } else if (mtd_is_bitflip(res)) { | |
212 | pr_info("nand_bbt: corrected error in BBT at " | |
213 | "0x%012llx\n", from & ~mtd->writesize); | |
214 | ret = res; | |
215 | } else { | |
216 | pr_info("nand_bbt: error reading BBT\n"); | |
1da177e4 LT |
217 | return res; |
218 | } | |
61b03bd7 | 219 | } |
1da177e4 LT |
220 | |
221 | /* Analyse data */ | |
222 | for (i = 0; i < len; i++) { | |
223 | uint8_t dat = buf[i]; | |
224 | for (j = 0; j < 8; j += bits, act += 2) { | |
225 | uint8_t tmp = (dat >> j) & msk; | |
226 | if (tmp == msk) | |
227 | continue; | |
e0c7d767 | 228 | if (reserved_block_code && (tmp == reserved_block_code)) { |
d0370219 BN |
229 | pr_info("nand_read_bbt: reserved block at 0x%012llx\n", |
230 | (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); | |
1da177e4 | 231 | this->bbt[offs + (act >> 3)] |= 0x2 << (act & 0x06); |
f1a28c02 | 232 | mtd->ecc_stats.bbtblocks++; |
1da177e4 LT |
233 | continue; |
234 | } | |
8b6e50c9 BN |
235 | /* |
236 | * Leave it for now, if it's matured we can | |
a0f5080e | 237 | * move this message to pr_debug. |
8b6e50c9 | 238 | */ |
d0370219 BN |
239 | pr_info("nand_read_bbt: bad block at 0x%012llx\n", |
240 | (loff_t)((offs << 2) + (act >> 1)) << this->bbt_erase_shift); | |
8b6e50c9 | 241 | /* Factory marked bad or worn out? */ |
1da177e4 LT |
242 | if (tmp == 0) |
243 | this->bbt[offs + (act >> 3)] |= 0x3 << (act & 0x06); | |
244 | else | |
245 | this->bbt[offs + (act >> 3)] |= 0x1 << (act & 0x06); | |
f1a28c02 | 246 | mtd->ecc_stats.badblocks++; |
61b03bd7 | 247 | } |
1da177e4 LT |
248 | } |
249 | totlen -= len; | |
250 | from += len; | |
251 | } | |
167a8d52 | 252 | return ret; |
1da177e4 LT |
253 | } |
254 | ||
255 | /** | |
256 | * read_abs_bbt - [GENERIC] Read the bad block table starting at a given page | |
8b6e50c9 BN |
257 | * @mtd: MTD device structure |
258 | * @buf: temporary buffer | |
259 | * @td: descriptor for the bad block table | |
596d7452 | 260 | * @chip: read the table for a specific chip, -1 read all chips; applies only if |
8b6e50c9 | 261 | * NAND_BBT_PERCHIP option is set |
1da177e4 | 262 | * |
8b6e50c9 BN |
263 | * Read the bad block table for all chips starting at a given page. We assume |
264 | * that the bbt bits are in consecutive order. | |
265 | */ | |
e0c7d767 | 266 | static int read_abs_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td, int chip) |
1da177e4 LT |
267 | { |
268 | struct nand_chip *this = mtd->priv; | |
269 | int res = 0, i; | |
1da177e4 | 270 | |
1da177e4 LT |
271 | if (td->options & NAND_BBT_PERCHIP) { |
272 | int offs = 0; | |
273 | for (i = 0; i < this->numchips; i++) { | |
274 | if (chip == -1 || chip == i) | |
df5b4e34 SAS |
275 | res = read_bbt(mtd, buf, td->pages[i], |
276 | this->chipsize >> this->bbt_erase_shift, | |
277 | td, offs); | |
1da177e4 LT |
278 | if (res) |
279 | return res; | |
280 | offs += this->chipsize >> (this->bbt_erase_shift + 2); | |
281 | } | |
282 | } else { | |
df5b4e34 SAS |
283 | res = read_bbt(mtd, buf, td->pages[0], |
284 | mtd->size >> this->bbt_erase_shift, td, 0); | |
1da177e4 LT |
285 | if (res) |
286 | return res; | |
287 | } | |
288 | return 0; | |
289 | } | |
290 | ||
8b6e50c9 | 291 | /* BBT marker is in the first page, no OOB */ |
7cba7b14 SAS |
292 | static int scan_read_raw_data(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |
293 | struct nand_bbt_descr *td) | |
294 | { | |
295 | size_t retlen; | |
296 | size_t len; | |
297 | ||
298 | len = td->len; | |
299 | if (td->options & NAND_BBT_VERSION) | |
300 | len++; | |
301 | ||
302 | return mtd->read(mtd, offs, len, &retlen, buf); | |
303 | } | |
304 | ||
8b6e50c9 | 305 | /* Scan read raw data from flash */ |
7cba7b14 | 306 | static int scan_read_raw_oob(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |
8593fbc6 TG |
307 | size_t len) |
308 | { | |
309 | struct mtd_oob_ops ops; | |
b64d39d8 | 310 | int res; |
8593fbc6 | 311 | |
0612b9dd | 312 | ops.mode = MTD_OPS_RAW; |
8593fbc6 TG |
313 | ops.ooboffs = 0; |
314 | ops.ooblen = mtd->oobsize; | |
8593fbc6 | 315 | |
b64d39d8 | 316 | while (len > 0) { |
105513cc BN |
317 | ops.datbuf = buf; |
318 | ops.len = min(len, (size_t)mtd->writesize); | |
319 | ops.oobbuf = buf + ops.len; | |
903cd06c | 320 | |
105513cc | 321 | res = mtd->read_oob(mtd, offs, &ops); |
b64d39d8 | 322 | |
afa17de2 | 323 | if (res) |
105513cc | 324 | return res; |
b64d39d8 ML |
325 | |
326 | buf += mtd->oobsize + mtd->writesize; | |
327 | len -= mtd->writesize; | |
328 | } | |
329 | return 0; | |
8593fbc6 TG |
330 | } |
331 | ||
7cba7b14 SAS |
332 | static int scan_read_raw(struct mtd_info *mtd, uint8_t *buf, loff_t offs, |
333 | size_t len, struct nand_bbt_descr *td) | |
334 | { | |
335 | if (td->options & NAND_BBT_NO_OOB) | |
336 | return scan_read_raw_data(mtd, buf, offs, td); | |
337 | else | |
338 | return scan_read_raw_oob(mtd, buf, offs, len); | |
339 | } | |
340 | ||
8b6e50c9 | 341 | /* Scan write data with oob to flash */ |
8593fbc6 TG |
342 | static int scan_write_bbt(struct mtd_info *mtd, loff_t offs, size_t len, |
343 | uint8_t *buf, uint8_t *oob) | |
344 | { | |
345 | struct mtd_oob_ops ops; | |
346 | ||
0612b9dd | 347 | ops.mode = MTD_OPS_PLACE_OOB; |
8593fbc6 TG |
348 | ops.ooboffs = 0; |
349 | ops.ooblen = mtd->oobsize; | |
350 | ops.datbuf = buf; | |
351 | ops.oobbuf = oob; | |
352 | ops.len = len; | |
353 | ||
354 | return mtd->write_oob(mtd, offs, &ops); | |
355 | } | |
356 | ||
7cba7b14 SAS |
357 | static u32 bbt_get_ver_offs(struct mtd_info *mtd, struct nand_bbt_descr *td) |
358 | { | |
359 | u32 ver_offs = td->veroffs; | |
360 | ||
361 | if (!(td->options & NAND_BBT_NO_OOB)) | |
362 | ver_offs += mtd->writesize; | |
363 | return ver_offs; | |
364 | } | |
365 | ||
1da177e4 LT |
366 | /** |
367 | * read_abs_bbts - [GENERIC] Read the bad block table(s) for all chips starting at a given page | |
8b6e50c9 BN |
368 | * @mtd: MTD device structure |
369 | * @buf: temporary buffer | |
370 | * @td: descriptor for the bad block table | |
371 | * @md: descriptor for the bad block table mirror | |
1da177e4 | 372 | * |
8b6e50c9 BN |
373 | * Read the bad block table(s) for all chips starting at a given page. We |
374 | * assume that the bbt bits are in consecutive order. | |
375 | */ | |
8593fbc6 TG |
376 | static int read_abs_bbts(struct mtd_info *mtd, uint8_t *buf, |
377 | struct nand_bbt_descr *td, struct nand_bbt_descr *md) | |
1da177e4 LT |
378 | { |
379 | struct nand_chip *this = mtd->priv; | |
380 | ||
61b03bd7 | 381 | /* Read the primary version, if available */ |
1da177e4 | 382 | if (td->options & NAND_BBT_VERSION) { |
69423d99 | 383 | scan_read_raw(mtd, buf, (loff_t)td->pages[0] << this->page_shift, |
7cba7b14 SAS |
384 | mtd->writesize, td); |
385 | td->version[0] = buf[bbt_get_ver_offs(mtd, td)]; | |
9a4d4d69 | 386 | pr_info("Bad block table at page %d, version 0x%02X\n", |
d0370219 | 387 | td->pages[0], td->version[0]); |
1da177e4 LT |
388 | } |
389 | ||
61b03bd7 | 390 | /* Read the mirror version, if available */ |
1da177e4 | 391 | if (md && (md->options & NAND_BBT_VERSION)) { |
69423d99 | 392 | scan_read_raw(mtd, buf, (loff_t)md->pages[0] << this->page_shift, |
7cba7b14 SAS |
393 | mtd->writesize, td); |
394 | md->version[0] = buf[bbt_get_ver_offs(mtd, md)]; | |
9a4d4d69 | 395 | pr_info("Bad block table at page %d, version 0x%02X\n", |
d0370219 | 396 | md->pages[0], md->version[0]); |
1da177e4 | 397 | } |
1da177e4 LT |
398 | return 1; |
399 | } | |
400 | ||
8b6e50c9 | 401 | /* Scan a given block full */ |
8593fbc6 TG |
402 | static int scan_block_full(struct mtd_info *mtd, struct nand_bbt_descr *bd, |
403 | loff_t offs, uint8_t *buf, size_t readlen, | |
404 | int scanlen, int len) | |
405 | { | |
406 | int ret, j; | |
407 | ||
7cba7b14 | 408 | ret = scan_read_raw_oob(mtd, buf, offs, readlen); |
afa17de2 | 409 | /* Ignore ECC errors when checking for BBM */ |
d57f4054 | 410 | if (ret && !mtd_is_bitflip_or_eccerr(ret)) |
8593fbc6 TG |
411 | return ret; |
412 | ||
413 | for (j = 0; j < len; j++, buf += scanlen) { | |
414 | if (check_pattern(buf, scanlen, mtd->writesize, bd)) | |
415 | return 1; | |
416 | } | |
417 | return 0; | |
418 | } | |
419 | ||
8b6e50c9 | 420 | /* Scan a given block partially */ |
8593fbc6 TG |
421 | static int scan_block_fast(struct mtd_info *mtd, struct nand_bbt_descr *bd, |
422 | loff_t offs, uint8_t *buf, int len) | |
423 | { | |
424 | struct mtd_oob_ops ops; | |
425 | int j, ret; | |
426 | ||
8593fbc6 TG |
427 | ops.ooblen = mtd->oobsize; |
428 | ops.oobbuf = buf; | |
429 | ops.ooboffs = 0; | |
430 | ops.datbuf = NULL; | |
0612b9dd | 431 | ops.mode = MTD_OPS_PLACE_OOB; |
8593fbc6 TG |
432 | |
433 | for (j = 0; j < len; j++) { | |
434 | /* | |
8b6e50c9 BN |
435 | * Read the full oob until read_oob is fixed to handle single |
436 | * byte reads for 16 bit buswidth. | |
8593fbc6 TG |
437 | */ |
438 | ret = mtd->read_oob(mtd, offs, &ops); | |
903cd06c | 439 | /* Ignore ECC errors when checking for BBM */ |
d57f4054 | 440 | if (ret && !mtd_is_bitflip_or_eccerr(ret)) |
8593fbc6 TG |
441 | return ret; |
442 | ||
443 | if (check_short_pattern(buf, bd)) | |
444 | return 1; | |
445 | ||
446 | offs += mtd->writesize; | |
447 | } | |
448 | return 0; | |
449 | } | |
450 | ||
1da177e4 LT |
451 | /** |
452 | * create_bbt - [GENERIC] Create a bad block table by scanning the device | |
8b6e50c9 BN |
453 | * @mtd: MTD device structure |
454 | * @buf: temporary buffer | |
455 | * @bd: descriptor for the good/bad block search pattern | |
456 | * @chip: create the table for a specific chip, -1 read all chips; applies only | |
457 | * if NAND_BBT_PERCHIP option is set | |
1da177e4 | 458 | * |
8b6e50c9 BN |
459 | * Create a bad block table by scanning the device for the given good/bad block |
460 | * identify pattern. | |
1da177e4 | 461 | */ |
8593fbc6 TG |
462 | static int create_bbt(struct mtd_info *mtd, uint8_t *buf, |
463 | struct nand_bbt_descr *bd, int chip) | |
1da177e4 LT |
464 | { |
465 | struct nand_chip *this = mtd->priv; | |
8593fbc6 | 466 | int i, numblocks, len, scanlen; |
1da177e4 LT |
467 | int startblock; |
468 | loff_t from; | |
8593fbc6 | 469 | size_t readlen; |
1da177e4 | 470 | |
9a4d4d69 | 471 | pr_info("Scanning device for bad blocks\n"); |
1da177e4 LT |
472 | |
473 | if (bd->options & NAND_BBT_SCANALLPAGES) | |
474 | len = 1 << (this->bbt_erase_shift - this->page_shift); | |
58373ff0 BN |
475 | else if (bd->options & NAND_BBT_SCAN2NDPAGE) |
476 | len = 2; | |
477 | else | |
478 | len = 1; | |
171650af AB |
479 | |
480 | if (!(bd->options & NAND_BBT_SCANEMPTY)) { | |
481 | /* We need only read few bytes from the OOB area */ | |
8593fbc6 | 482 | scanlen = 0; |
eeada24d AB |
483 | readlen = bd->len; |
484 | } else { | |
171650af | 485 | /* Full page content should be read */ |
28318776 JE |
486 | scanlen = mtd->writesize + mtd->oobsize; |
487 | readlen = len * mtd->writesize; | |
eeada24d | 488 | } |
1da177e4 LT |
489 | |
490 | if (chip == -1) { | |
8b6e50c9 BN |
491 | /* |
492 | * Note that numblocks is 2 * (real numblocks) here, see i+=2 | |
493 | * below as it makes shifting and masking less painful | |
494 | */ | |
1da177e4 LT |
495 | numblocks = mtd->size >> (this->bbt_erase_shift - 1); |
496 | startblock = 0; | |
497 | from = 0; | |
498 | } else { | |
499 | if (chip >= this->numchips) { | |
9a4d4d69 | 500 | pr_warn("create_bbt(): chipnr (%d) > available chips (%d)\n", |
e0c7d767 | 501 | chip + 1, this->numchips); |
171650af | 502 | return -EINVAL; |
1da177e4 LT |
503 | } |
504 | numblocks = this->chipsize >> (this->bbt_erase_shift - 1); | |
505 | startblock = chip * numblocks; | |
506 | numblocks += startblock; | |
69423d99 | 507 | from = (loff_t)startblock << (this->bbt_erase_shift - 1); |
1da177e4 | 508 | } |
61b03bd7 | 509 | |
5fb1549d | 510 | if (this->bbt_options & NAND_BBT_SCANLASTPAGE) |
b60b08b0 KC |
511 | from += mtd->erasesize - (mtd->writesize * len); |
512 | ||
1da177e4 | 513 | for (i = startblock; i < numblocks;) { |
eeada24d | 514 | int ret; |
61b03bd7 | 515 | |
7cba7b14 SAS |
516 | BUG_ON(bd->options & NAND_BBT_NO_OOB); |
517 | ||
8593fbc6 TG |
518 | if (bd->options & NAND_BBT_SCANALLPAGES) |
519 | ret = scan_block_full(mtd, bd, from, buf, readlen, | |
520 | scanlen, len); | |
521 | else | |
522 | ret = scan_block_fast(mtd, bd, from, buf, len); | |
523 | ||
524 | if (ret < 0) | |
525 | return ret; | |
526 | ||
527 | if (ret) { | |
528 | this->bbt[i >> 3] |= 0x03 << (i & 0x6); | |
9a4d4d69 | 529 | pr_warn("Bad eraseblock %d at 0x%012llx\n", |
d0370219 | 530 | i >> 1, (unsigned long long)from); |
f1a28c02 | 531 | mtd->ecc_stats.badblocks++; |
1da177e4 | 532 | } |
8593fbc6 | 533 | |
1da177e4 LT |
534 | i += 2; |
535 | from += (1 << this->bbt_erase_shift); | |
536 | } | |
eeada24d | 537 | return 0; |
1da177e4 LT |
538 | } |
539 | ||
540 | /** | |
541 | * search_bbt - [GENERIC] scan the device for a specific bad block table | |
8b6e50c9 BN |
542 | * @mtd: MTD device structure |
543 | * @buf: temporary buffer | |
544 | * @td: descriptor for the bad block table | |
1da177e4 | 545 | * |
8b6e50c9 BN |
546 | * Read the bad block table by searching for a given ident pattern. Search is |
547 | * preformed either from the beginning up or from the end of the device | |
548 | * downwards. The search starts always at the start of a block. If the option | |
549 | * NAND_BBT_PERCHIP is given, each chip is searched for a bbt, which contains | |
550 | * the bad block information of this chip. This is necessary to provide support | |
551 | * for certain DOC devices. | |
1da177e4 | 552 | * |
8b6e50c9 | 553 | * The bbt ident pattern resides in the oob area of the first page in a block. |
1da177e4 | 554 | */ |
e0c7d767 | 555 | static int search_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *td) |
1da177e4 LT |
556 | { |
557 | struct nand_chip *this = mtd->priv; | |
558 | int i, chips; | |
559 | int bits, startblock, block, dir; | |
28318776 | 560 | int scanlen = mtd->writesize + mtd->oobsize; |
1da177e4 | 561 | int bbtblocks; |
8593fbc6 | 562 | int blocktopage = this->bbt_erase_shift - this->page_shift; |
1da177e4 | 563 | |
8b6e50c9 | 564 | /* Search direction top -> down? */ |
1da177e4 | 565 | if (td->options & NAND_BBT_LASTBLOCK) { |
e0c7d767 | 566 | startblock = (mtd->size >> this->bbt_erase_shift) - 1; |
1da177e4 LT |
567 | dir = -1; |
568 | } else { | |
61b03bd7 | 569 | startblock = 0; |
1da177e4 | 570 | dir = 1; |
61b03bd7 TG |
571 | } |
572 | ||
8b6e50c9 | 573 | /* Do we have a bbt per chip? */ |
1da177e4 LT |
574 | if (td->options & NAND_BBT_PERCHIP) { |
575 | chips = this->numchips; | |
576 | bbtblocks = this->chipsize >> this->bbt_erase_shift; | |
577 | startblock &= bbtblocks - 1; | |
578 | } else { | |
579 | chips = 1; | |
580 | bbtblocks = mtd->size >> this->bbt_erase_shift; | |
581 | } | |
61b03bd7 | 582 | |
1da177e4 LT |
583 | /* Number of bits for each erase block in the bbt */ |
584 | bits = td->options & NAND_BBT_NRBITS_MSK; | |
61b03bd7 | 585 | |
1da177e4 LT |
586 | for (i = 0; i < chips; i++) { |
587 | /* Reset version information */ | |
61b03bd7 | 588 | td->version[i] = 0; |
1da177e4 LT |
589 | td->pages[i] = -1; |
590 | /* Scan the maximum number of blocks */ | |
591 | for (block = 0; block < td->maxblocks; block++) { | |
8593fbc6 | 592 | |
1da177e4 | 593 | int actblock = startblock + dir * block; |
69423d99 | 594 | loff_t offs = (loff_t)actblock << this->bbt_erase_shift; |
8593fbc6 | 595 | |
1da177e4 | 596 | /* Read first page */ |
7cba7b14 | 597 | scan_read_raw(mtd, buf, offs, mtd->writesize, td); |
28318776 | 598 | if (!check_pattern(buf, scanlen, mtd->writesize, td)) { |
8593fbc6 | 599 | td->pages[i] = actblock << blocktopage; |
1da177e4 | 600 | if (td->options & NAND_BBT_VERSION) { |
7cba7b14 SAS |
601 | offs = bbt_get_ver_offs(mtd, td); |
602 | td->version[i] = buf[offs]; | |
1da177e4 LT |
603 | } |
604 | break; | |
605 | } | |
606 | } | |
607 | startblock += this->chipsize >> this->bbt_erase_shift; | |
608 | } | |
609 | /* Check, if we found a bbt for each requested chip */ | |
610 | for (i = 0; i < chips; i++) { | |
611 | if (td->pages[i] == -1) | |
9a4d4d69 | 612 | pr_warn("Bad block table not found for chip %d\n", i); |
1da177e4 | 613 | else |
d0370219 BN |
614 | pr_info("Bad block table found at page %d, version " |
615 | "0x%02X\n", td->pages[i], td->version[i]); | |
1da177e4 | 616 | } |
61b03bd7 | 617 | return 0; |
1da177e4 LT |
618 | } |
619 | ||
620 | /** | |
621 | * search_read_bbts - [GENERIC] scan the device for bad block table(s) | |
8b6e50c9 BN |
622 | * @mtd: MTD device structure |
623 | * @buf: temporary buffer | |
624 | * @td: descriptor for the bad block table | |
625 | * @md: descriptor for the bad block table mirror | |
1da177e4 | 626 | * |
8b6e50c9 BN |
627 | * Search and read the bad block table(s). |
628 | */ | |
e0c7d767 | 629 | static int search_read_bbts(struct mtd_info *mtd, uint8_t * buf, struct nand_bbt_descr *td, struct nand_bbt_descr *md) |
1da177e4 LT |
630 | { |
631 | /* Search the primary table */ | |
e0c7d767 | 632 | search_bbt(mtd, buf, td); |
61b03bd7 | 633 | |
1da177e4 LT |
634 | /* Search the mirror table */ |
635 | if (md) | |
e0c7d767 | 636 | search_bbt(mtd, buf, md); |
61b03bd7 | 637 | |
1da177e4 | 638 | /* Force result check */ |
61b03bd7 | 639 | return 1; |
1da177e4 | 640 | } |
1da177e4 | 641 | |
61b03bd7 | 642 | /** |
1da177e4 | 643 | * write_bbt - [GENERIC] (Re)write the bad block table |
8b6e50c9 BN |
644 | * @mtd: MTD device structure |
645 | * @buf: temporary buffer | |
646 | * @td: descriptor for the bad block table | |
647 | * @md: descriptor for the bad block table mirror | |
648 | * @chipsel: selector for a specific chip, -1 for all | |
1da177e4 | 649 | * |
8b6e50c9 BN |
650 | * (Re)write the bad block table. |
651 | */ | |
e0c7d767 | 652 | static int write_bbt(struct mtd_info *mtd, uint8_t *buf, |
9223a456 TG |
653 | struct nand_bbt_descr *td, struct nand_bbt_descr *md, |
654 | int chipsel) | |
1da177e4 LT |
655 | { |
656 | struct nand_chip *this = mtd->priv; | |
1da177e4 LT |
657 | struct erase_info einfo; |
658 | int i, j, res, chip = 0; | |
659 | int bits, startblock, dir, page, offs, numblocks, sft, sftmsk; | |
9223a456 | 660 | int nrchips, bbtoffs, pageoffs, ooboffs; |
1da177e4 LT |
661 | uint8_t msk[4]; |
662 | uint8_t rcode = td->reserved_block_code; | |
8593fbc6 | 663 | size_t retlen, len = 0; |
1da177e4 | 664 | loff_t to; |
8593fbc6 TG |
665 | struct mtd_oob_ops ops; |
666 | ||
667 | ops.ooblen = mtd->oobsize; | |
668 | ops.ooboffs = 0; | |
669 | ops.datbuf = NULL; | |
0612b9dd | 670 | ops.mode = MTD_OPS_PLACE_OOB; |
1da177e4 LT |
671 | |
672 | if (!rcode) | |
673 | rcode = 0xff; | |
8b6e50c9 | 674 | /* Write bad block table per chip rather than per device? */ |
1da177e4 | 675 | if (td->options & NAND_BBT_PERCHIP) { |
e0c7d767 | 676 | numblocks = (int)(this->chipsize >> this->bbt_erase_shift); |
8b6e50c9 | 677 | /* Full device write or specific chip? */ |
1da177e4 LT |
678 | if (chipsel == -1) { |
679 | nrchips = this->numchips; | |
680 | } else { | |
681 | nrchips = chipsel + 1; | |
682 | chip = chipsel; | |
683 | } | |
684 | } else { | |
e0c7d767 | 685 | numblocks = (int)(mtd->size >> this->bbt_erase_shift); |
1da177e4 | 686 | nrchips = 1; |
61b03bd7 TG |
687 | } |
688 | ||
1da177e4 LT |
689 | /* Loop through the chips */ |
690 | for (; chip < nrchips; chip++) { | |
8b6e50c9 BN |
691 | /* |
692 | * There was already a version of the table, reuse the page | |
61b03bd7 | 693 | * This applies for absolute placement too, as we have the |
1da177e4 LT |
694 | * page nr. in td->pages. |
695 | */ | |
696 | if (td->pages[chip] != -1) { | |
697 | page = td->pages[chip]; | |
698 | goto write; | |
61b03bd7 | 699 | } |
1da177e4 | 700 | |
8b6e50c9 BN |
701 | /* |
702 | * Automatic placement of the bad block table. Search direction | |
703 | * top -> down? | |
704 | */ | |
1da177e4 LT |
705 | if (td->options & NAND_BBT_LASTBLOCK) { |
706 | startblock = numblocks * (chip + 1) - 1; | |
707 | dir = -1; | |
708 | } else { | |
709 | startblock = chip * numblocks; | |
710 | dir = 1; | |
61b03bd7 | 711 | } |
1da177e4 LT |
712 | |
713 | for (i = 0; i < td->maxblocks; i++) { | |
714 | int block = startblock + dir * i; | |
715 | /* Check, if the block is bad */ | |
9223a456 TG |
716 | switch ((this->bbt[block >> 2] >> |
717 | (2 * (block & 0x03))) & 0x03) { | |
1da177e4 LT |
718 | case 0x01: |
719 | case 0x03: | |
720 | continue; | |
721 | } | |
9223a456 TG |
722 | page = block << |
723 | (this->bbt_erase_shift - this->page_shift); | |
1da177e4 LT |
724 | /* Check, if the block is used by the mirror table */ |
725 | if (!md || md->pages[chip] != page) | |
726 | goto write; | |
727 | } | |
9a4d4d69 | 728 | pr_err("No space left to write bad block table\n"); |
1da177e4 | 729 | return -ENOSPC; |
e0c7d767 | 730 | write: |
1da177e4 LT |
731 | |
732 | /* Set up shift count and masks for the flash table */ | |
733 | bits = td->options & NAND_BBT_NRBITS_MSK; | |
9223a456 | 734 | msk[2] = ~rcode; |
1da177e4 | 735 | switch (bits) { |
9223a456 TG |
736 | case 1: sft = 3; sftmsk = 0x07; msk[0] = 0x00; msk[1] = 0x01; |
737 | msk[3] = 0x01; | |
738 | break; | |
739 | case 2: sft = 2; sftmsk = 0x06; msk[0] = 0x00; msk[1] = 0x01; | |
740 | msk[3] = 0x03; | |
741 | break; | |
742 | case 4: sft = 1; sftmsk = 0x04; msk[0] = 0x00; msk[1] = 0x0C; | |
743 | msk[3] = 0x0f; | |
744 | break; | |
745 | case 8: sft = 0; sftmsk = 0x00; msk[0] = 0x00; msk[1] = 0x0F; | |
746 | msk[3] = 0xff; | |
747 | break; | |
1da177e4 LT |
748 | default: return -EINVAL; |
749 | } | |
61b03bd7 | 750 | |
1da177e4 | 751 | bbtoffs = chip * (numblocks >> 2); |
61b03bd7 | 752 | |
596d7452 | 753 | to = ((loff_t)page) << this->page_shift; |
1da177e4 | 754 | |
8b6e50c9 | 755 | /* Must we save the block contents? */ |
1da177e4 LT |
756 | if (td->options & NAND_BBT_SAVECONTENT) { |
757 | /* Make it block aligned */ | |
596d7452 | 758 | to &= ~((loff_t)((1 << this->bbt_erase_shift) - 1)); |
1da177e4 | 759 | len = 1 << this->bbt_erase_shift; |
9223a456 | 760 | res = mtd->read(mtd, to, len, &retlen, buf); |
1da177e4 LT |
761 | if (res < 0) { |
762 | if (retlen != len) { | |
d0370219 BN |
763 | pr_info("nand_bbt: error reading block " |
764 | "for writing the bad block table\n"); | |
1da177e4 LT |
765 | return res; |
766 | } | |
d0370219 BN |
767 | pr_warn("nand_bbt: ECC error while reading " |
768 | "block for writing bad block table\n"); | |
1da177e4 | 769 | } |
9223a456 | 770 | /* Read oob data */ |
7014568b | 771 | ops.ooblen = (len >> this->page_shift) * mtd->oobsize; |
8593fbc6 TG |
772 | ops.oobbuf = &buf[len]; |
773 | res = mtd->read_oob(mtd, to + mtd->writesize, &ops); | |
7014568b | 774 | if (res < 0 || ops.oobretlen != ops.ooblen) |
9223a456 TG |
775 | goto outerr; |
776 | ||
1da177e4 LT |
777 | /* Calc the byte offset in the buffer */ |
778 | pageoffs = page - (int)(to >> this->page_shift); | |
779 | offs = pageoffs << this->page_shift; | |
780 | /* Preset the bbt area with 0xff */ | |
596d7452 | 781 | memset(&buf[offs], 0xff, (size_t)(numblocks >> sft)); |
9223a456 TG |
782 | ooboffs = len + (pageoffs * mtd->oobsize); |
783 | ||
7cba7b14 SAS |
784 | } else if (td->options & NAND_BBT_NO_OOB) { |
785 | ooboffs = 0; | |
786 | offs = td->len; | |
8b6e50c9 | 787 | /* The version byte */ |
7cba7b14 SAS |
788 | if (td->options & NAND_BBT_VERSION) |
789 | offs++; | |
790 | /* Calc length */ | |
596d7452 | 791 | len = (size_t)(numblocks >> sft); |
7cba7b14 | 792 | len += offs; |
8b6e50c9 | 793 | /* Make it page aligned! */ |
7cba7b14 SAS |
794 | len = ALIGN(len, mtd->writesize); |
795 | /* Preset the buffer with 0xff */ | |
796 | memset(buf, 0xff, len); | |
797 | /* Pattern is located at the begin of first page */ | |
798 | memcpy(buf, td->pattern, td->len); | |
1da177e4 LT |
799 | } else { |
800 | /* Calc length */ | |
596d7452 | 801 | len = (size_t)(numblocks >> sft); |
8b6e50c9 | 802 | /* Make it page aligned! */ |
cda32091 | 803 | len = ALIGN(len, mtd->writesize); |
1da177e4 | 804 | /* Preset the buffer with 0xff */ |
9223a456 TG |
805 | memset(buf, 0xff, len + |
806 | (len >> this->page_shift)* mtd->oobsize); | |
1da177e4 | 807 | offs = 0; |
9223a456 | 808 | ooboffs = len; |
1da177e4 | 809 | /* Pattern is located in oob area of first page */ |
9223a456 | 810 | memcpy(&buf[ooboffs + td->offs], td->pattern, td->len); |
1da177e4 | 811 | } |
61b03bd7 | 812 | |
9223a456 TG |
813 | if (td->options & NAND_BBT_VERSION) |
814 | buf[ooboffs + td->veroffs] = td->version[chip]; | |
815 | ||
8b6e50c9 | 816 | /* Walk through the memory table */ |
e0c7d767 | 817 | for (i = 0; i < numblocks;) { |
1da177e4 LT |
818 | uint8_t dat; |
819 | dat = this->bbt[bbtoffs + (i >> 2)]; | |
e0c7d767 | 820 | for (j = 0; j < 4; j++, i++) { |
1da177e4 | 821 | int sftcnt = (i << (3 - sft)) & sftmsk; |
8b6e50c9 | 822 | /* Do not store the reserved bbt blocks! */ |
9223a456 TG |
823 | buf[offs + (i >> sft)] &= |
824 | ~(msk[dat & 0x03] << sftcnt); | |
1da177e4 LT |
825 | dat >>= 2; |
826 | } | |
827 | } | |
61b03bd7 | 828 | |
e0c7d767 | 829 | memset(&einfo, 0, sizeof(einfo)); |
1da177e4 | 830 | einfo.mtd = mtd; |
69423d99 | 831 | einfo.addr = to; |
1da177e4 | 832 | einfo.len = 1 << this->bbt_erase_shift; |
e0c7d767 | 833 | res = nand_erase_nand(mtd, &einfo, 1); |
9223a456 TG |
834 | if (res < 0) |
835 | goto outerr; | |
61b03bd7 | 836 | |
7cba7b14 SAS |
837 | res = scan_write_bbt(mtd, to, len, buf, |
838 | td->options & NAND_BBT_NO_OOB ? NULL : | |
839 | &buf[len]); | |
9223a456 TG |
840 | if (res < 0) |
841 | goto outerr; | |
842 | ||
d0370219 BN |
843 | pr_info("Bad block table written to 0x%012llx, version 0x%02X\n", |
844 | (unsigned long long)to, td->version[chip]); | |
61b03bd7 | 845 | |
1da177e4 LT |
846 | /* Mark it as used */ |
847 | td->pages[chip] = page; | |
61b03bd7 | 848 | } |
1da177e4 | 849 | return 0; |
9223a456 TG |
850 | |
851 | outerr: | |
d0370219 | 852 | pr_warn("nand_bbt: error while writing bad block table %d\n", res); |
9223a456 | 853 | return res; |
1da177e4 LT |
854 | } |
855 | ||
856 | /** | |
857 | * nand_memory_bbt - [GENERIC] create a memory based bad block table | |
8b6e50c9 BN |
858 | * @mtd: MTD device structure |
859 | * @bd: descriptor for the good/bad block search pattern | |
1da177e4 | 860 | * |
8b6e50c9 BN |
861 | * The function creates a memory based bbt by scanning the device for |
862 | * manufacturer / software marked good / bad blocks. | |
863 | */ | |
e0c7d767 | 864 | static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) |
1da177e4 LT |
865 | { |
866 | struct nand_chip *this = mtd->priv; | |
867 | ||
171650af | 868 | bd->options &= ~NAND_BBT_SCANEMPTY; |
4bf63fcb | 869 | return create_bbt(mtd, this->buffers->databuf, bd, -1); |
1da177e4 LT |
870 | } |
871 | ||
872 | /** | |
e0c7d767 | 873 | * check_create - [GENERIC] create and write bbt(s) if necessary |
8b6e50c9 BN |
874 | * @mtd: MTD device structure |
875 | * @buf: temporary buffer | |
876 | * @bd: descriptor for the good/bad block search pattern | |
1da177e4 | 877 | * |
8b6e50c9 BN |
878 | * The function checks the results of the previous call to read_bbt and creates |
879 | * / updates the bbt(s) if necessary. Creation is necessary if no bbt was found | |
880 | * for the chip/device. Update is necessary if one of the tables is missing or | |
881 | * the version nr. of one table is less than the other. | |
882 | */ | |
e0c7d767 | 883 | static int check_create(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr *bd) |
1da177e4 | 884 | { |
b61bf5bb | 885 | int i, chips, writeops, create, chipsel, res; |
1da177e4 LT |
886 | struct nand_chip *this = mtd->priv; |
887 | struct nand_bbt_descr *td = this->bbt_td; | |
888 | struct nand_bbt_descr *md = this->bbt_md; | |
889 | struct nand_bbt_descr *rd, *rd2; | |
890 | ||
8b6e50c9 | 891 | /* Do we have a bbt per chip? */ |
61b03bd7 | 892 | if (td->options & NAND_BBT_PERCHIP) |
1da177e4 | 893 | chips = this->numchips; |
61b03bd7 | 894 | else |
1da177e4 | 895 | chips = 1; |
61b03bd7 | 896 | |
1da177e4 LT |
897 | for (i = 0; i < chips; i++) { |
898 | writeops = 0; | |
b61bf5bb | 899 | create = 0; |
1da177e4 LT |
900 | rd = NULL; |
901 | rd2 = NULL; | |
8b6e50c9 | 902 | /* Per chip or per device? */ |
1da177e4 | 903 | chipsel = (td->options & NAND_BBT_PERCHIP) ? i : -1; |
8b6e50c9 | 904 | /* Mirrored table available? */ |
1da177e4 LT |
905 | if (md) { |
906 | if (td->pages[i] == -1 && md->pages[i] == -1) { | |
b61bf5bb | 907 | create = 1; |
1da177e4 | 908 | writeops = 0x03; |
c5e8ef9c | 909 | } else if (td->pages[i] == -1) { |
61b03bd7 | 910 | rd = md; |
1da177e4 | 911 | td->version[i] = md->version[i]; |
596d7452 | 912 | writeops = 0x01; |
c5e8ef9c | 913 | } else if (md->pages[i] == -1) { |
1da177e4 LT |
914 | rd = td; |
915 | md->version[i] = td->version[i]; | |
596d7452 | 916 | writeops = 0x02; |
c5e8ef9c | 917 | } else if (td->version[i] == md->version[i]) { |
1da177e4 LT |
918 | rd = td; |
919 | if (!(td->options & NAND_BBT_VERSION)) | |
920 | rd2 = md; | |
c5e8ef9c | 921 | } else if (((int8_t)(td->version[i] - md->version[i])) > 0) { |
1da177e4 LT |
922 | rd = td; |
923 | md->version[i] = td->version[i]; | |
596d7452 | 924 | writeops = 0x02; |
1da177e4 LT |
925 | } else { |
926 | rd = md; | |
927 | td->version[i] = md->version[i]; | |
596d7452 | 928 | writeops = 0x01; |
1da177e4 | 929 | } |
1da177e4 LT |
930 | } else { |
931 | if (td->pages[i] == -1) { | |
b61bf5bb | 932 | create = 1; |
1da177e4 | 933 | writeops = 0x01; |
b61bf5bb BN |
934 | } else { |
935 | rd = td; | |
1da177e4 | 936 | } |
1da177e4 | 937 | } |
b61bf5bb BN |
938 | |
939 | if (create) { | |
940 | /* Create the bad block table by scanning the device? */ | |
941 | if (!(td->options & NAND_BBT_CREATE)) | |
942 | continue; | |
943 | ||
944 | /* Create the table in memory by scanning the chip(s) */ | |
945 | if (!(this->bbt_options & NAND_BBT_CREATE_EMPTY)) | |
946 | create_bbt(mtd, buf, bd, chipsel); | |
947 | ||
948 | td->version[i] = 1; | |
949 | if (md) | |
950 | md->version[i] = 1; | |
951 | } | |
952 | ||
8b6e50c9 | 953 | /* Read back first? */ |
1da177e4 | 954 | if (rd) |
e0c7d767 | 955 | read_abs_bbt(mtd, buf, rd, chipsel); |
8b6e50c9 | 956 | /* If they weren't versioned, read both */ |
1da177e4 | 957 | if (rd2) |
e0c7d767 | 958 | read_abs_bbt(mtd, buf, rd2, chipsel); |
1da177e4 | 959 | |
8b6e50c9 | 960 | /* Write the bad block table to the device? */ |
1da177e4 | 961 | if ((writeops & 0x01) && (td->options & NAND_BBT_WRITE)) { |
e0c7d767 | 962 | res = write_bbt(mtd, buf, td, md, chipsel); |
1da177e4 LT |
963 | if (res < 0) |
964 | return res; | |
965 | } | |
61b03bd7 | 966 | |
8b6e50c9 | 967 | /* Write the mirror bad block table to the device? */ |
1da177e4 | 968 | if ((writeops & 0x02) && md && (md->options & NAND_BBT_WRITE)) { |
e0c7d767 | 969 | res = write_bbt(mtd, buf, md, td, chipsel); |
1da177e4 LT |
970 | if (res < 0) |
971 | return res; | |
972 | } | |
973 | } | |
61b03bd7 | 974 | return 0; |
1da177e4 LT |
975 | } |
976 | ||
977 | /** | |
61b03bd7 | 978 | * mark_bbt_regions - [GENERIC] mark the bad block table regions |
8b6e50c9 BN |
979 | * @mtd: MTD device structure |
980 | * @td: bad block table descriptor | |
1da177e4 | 981 | * |
8b6e50c9 BN |
982 | * The bad block table regions are marked as "bad" to prevent accidental |
983 | * erasures / writes. The regions are identified by the mark 0x02. | |
984 | */ | |
e0c7d767 | 985 | static void mark_bbt_region(struct mtd_info *mtd, struct nand_bbt_descr *td) |
1da177e4 LT |
986 | { |
987 | struct nand_chip *this = mtd->priv; | |
988 | int i, j, chips, block, nrblocks, update; | |
989 | uint8_t oldval, newval; | |
990 | ||
8b6e50c9 | 991 | /* Do we have a bbt per chip? */ |
1da177e4 LT |
992 | if (td->options & NAND_BBT_PERCHIP) { |
993 | chips = this->numchips; | |
994 | nrblocks = (int)(this->chipsize >> this->bbt_erase_shift); | |
995 | } else { | |
996 | chips = 1; | |
997 | nrblocks = (int)(mtd->size >> this->bbt_erase_shift); | |
61b03bd7 TG |
998 | } |
999 | ||
1da177e4 LT |
1000 | for (i = 0; i < chips; i++) { |
1001 | if ((td->options & NAND_BBT_ABSPAGE) || | |
1002 | !(td->options & NAND_BBT_WRITE)) { | |
e0c7d767 DW |
1003 | if (td->pages[i] == -1) |
1004 | continue; | |
1da177e4 | 1005 | block = td->pages[i] >> (this->bbt_erase_shift - this->page_shift); |
61b03bd7 | 1006 | block <<= 1; |
1da177e4 LT |
1007 | oldval = this->bbt[(block >> 3)]; |
1008 | newval = oldval | (0x2 << (block & 0x06)); | |
1009 | this->bbt[(block >> 3)] = newval; | |
1010 | if ((oldval != newval) && td->reserved_block_code) | |
69423d99 | 1011 | nand_update_bbt(mtd, (loff_t)block << (this->bbt_erase_shift - 1)); |
1da177e4 LT |
1012 | continue; |
1013 | } | |
1014 | update = 0; | |
1015 | if (td->options & NAND_BBT_LASTBLOCK) | |
1016 | block = ((i + 1) * nrblocks) - td->maxblocks; | |
61b03bd7 | 1017 | else |
1da177e4 | 1018 | block = i * nrblocks; |
61b03bd7 | 1019 | block <<= 1; |
1da177e4 LT |
1020 | for (j = 0; j < td->maxblocks; j++) { |
1021 | oldval = this->bbt[(block >> 3)]; | |
1022 | newval = oldval | (0x2 << (block & 0x06)); | |
1023 | this->bbt[(block >> 3)] = newval; | |
e0c7d767 DW |
1024 | if (oldval != newval) |
1025 | update = 1; | |
1da177e4 | 1026 | block += 2; |
61b03bd7 | 1027 | } |
8b6e50c9 BN |
1028 | /* |
1029 | * If we want reserved blocks to be recorded to flash, and some | |
1030 | * new ones have been marked, then we need to update the stored | |
1031 | * bbts. This should only happen once. | |
1032 | */ | |
1da177e4 | 1033 | if (update && td->reserved_block_code) |
69423d99 | 1034 | nand_update_bbt(mtd, (loff_t)(block - 2) << (this->bbt_erase_shift - 1)); |
1da177e4 LT |
1035 | } |
1036 | } | |
1037 | ||
7cba7b14 SAS |
1038 | /** |
1039 | * verify_bbt_descr - verify the bad block description | |
8b6e50c9 BN |
1040 | * @mtd: MTD device structure |
1041 | * @bd: the table to verify | |
7cba7b14 SAS |
1042 | * |
1043 | * This functions performs a few sanity checks on the bad block description | |
1044 | * table. | |
1045 | */ | |
1046 | static void verify_bbt_descr(struct mtd_info *mtd, struct nand_bbt_descr *bd) | |
1047 | { | |
1048 | struct nand_chip *this = mtd->priv; | |
7912a5e7 SF |
1049 | u32 pattern_len; |
1050 | u32 bits; | |
7cba7b14 SAS |
1051 | u32 table_size; |
1052 | ||
1053 | if (!bd) | |
1054 | return; | |
7912a5e7 SF |
1055 | |
1056 | pattern_len = bd->len; | |
1057 | bits = bd->options & NAND_BBT_NRBITS_MSK; | |
1058 | ||
a40f7341 | 1059 | BUG_ON((this->bbt_options & NAND_BBT_NO_OOB) && |
bb9ebd4e | 1060 | !(this->bbt_options & NAND_BBT_USE_FLASH)); |
7cba7b14 SAS |
1061 | BUG_ON(!bits); |
1062 | ||
1063 | if (bd->options & NAND_BBT_VERSION) | |
1064 | pattern_len++; | |
1065 | ||
1066 | if (bd->options & NAND_BBT_NO_OOB) { | |
bb9ebd4e | 1067 | BUG_ON(!(this->bbt_options & NAND_BBT_USE_FLASH)); |
a40f7341 | 1068 | BUG_ON(!(this->bbt_options & NAND_BBT_NO_OOB)); |
7cba7b14 SAS |
1069 | BUG_ON(bd->offs); |
1070 | if (bd->options & NAND_BBT_VERSION) | |
1071 | BUG_ON(bd->veroffs != bd->len); | |
1072 | BUG_ON(bd->options & NAND_BBT_SAVECONTENT); | |
1073 | } | |
1074 | ||
1075 | if (bd->options & NAND_BBT_PERCHIP) | |
1076 | table_size = this->chipsize >> this->bbt_erase_shift; | |
1077 | else | |
1078 | table_size = mtd->size >> this->bbt_erase_shift; | |
1079 | table_size >>= 3; | |
1080 | table_size *= bits; | |
1081 | if (bd->options & NAND_BBT_NO_OOB) | |
1082 | table_size += pattern_len; | |
1083 | BUG_ON(table_size > (1 << this->bbt_erase_shift)); | |
1084 | } | |
1085 | ||
1da177e4 LT |
1086 | /** |
1087 | * nand_scan_bbt - [NAND Interface] scan, find, read and maybe create bad block table(s) | |
8b6e50c9 BN |
1088 | * @mtd: MTD device structure |
1089 | * @bd: descriptor for the good/bad block search pattern | |
1da177e4 | 1090 | * |
8b6e50c9 BN |
1091 | * The function checks, if a bad block table(s) is/are already available. If |
1092 | * not it scans the device for manufacturer marked good / bad blocks and writes | |
1093 | * the bad block table(s) to the selected place. | |
1da177e4 | 1094 | * |
8b6e50c9 BN |
1095 | * The bad block table memory is allocated here. It must be freed by calling |
1096 | * the nand_free_bbt function. | |
1097 | */ | |
e0c7d767 | 1098 | int nand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd) |
1da177e4 LT |
1099 | { |
1100 | struct nand_chip *this = mtd->priv; | |
1101 | int len, res = 0; | |
1102 | uint8_t *buf; | |
1103 | struct nand_bbt_descr *td = this->bbt_td; | |
1104 | struct nand_bbt_descr *md = this->bbt_md; | |
1105 | ||
1106 | len = mtd->size >> (this->bbt_erase_shift + 2); | |
8b6e50c9 BN |
1107 | /* |
1108 | * Allocate memory (2bit per block) and clear the memory bad block | |
1109 | * table. | |
1110 | */ | |
95b93a0c | 1111 | this->bbt = kzalloc(len, GFP_KERNEL); |
0870066d | 1112 | if (!this->bbt) |
1da177e4 | 1113 | return -ENOMEM; |
1da177e4 | 1114 | |
8b6e50c9 BN |
1115 | /* |
1116 | * If no primary table decriptor is given, scan the device to build a | |
1117 | * memory based bad block table. | |
1da177e4 | 1118 | */ |
eeada24d AB |
1119 | if (!td) { |
1120 | if ((res = nand_memory_bbt(mtd, bd))) { | |
d0370219 | 1121 | pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n"); |
e0c7d767 | 1122 | kfree(this->bbt); |
eeada24d AB |
1123 | this->bbt = NULL; |
1124 | } | |
1125 | return res; | |
1126 | } | |
7cba7b14 SAS |
1127 | verify_bbt_descr(mtd, td); |
1128 | verify_bbt_descr(mtd, md); | |
1da177e4 LT |
1129 | |
1130 | /* Allocate a temporary buffer for one eraseblock incl. oob */ | |
1131 | len = (1 << this->bbt_erase_shift); | |
1132 | len += (len >> this->page_shift) * mtd->oobsize; | |
c3f8abf4 | 1133 | buf = vmalloc(len); |
1da177e4 | 1134 | if (!buf) { |
e0c7d767 | 1135 | kfree(this->bbt); |
1da177e4 LT |
1136 | this->bbt = NULL; |
1137 | return -ENOMEM; | |
1138 | } | |
61b03bd7 | 1139 | |
8b6e50c9 | 1140 | /* Is the bbt at a given page? */ |
1da177e4 | 1141 | if (td->options & NAND_BBT_ABSPAGE) { |
e0c7d767 | 1142 | res = read_abs_bbts(mtd, buf, td, md); |
61b03bd7 | 1143 | } else { |
1da177e4 | 1144 | /* Search the bad block table using a pattern in oob */ |
e0c7d767 | 1145 | res = search_read_bbts(mtd, buf, td, md); |
61b03bd7 | 1146 | } |
1da177e4 | 1147 | |
61b03bd7 | 1148 | if (res) |
e0c7d767 | 1149 | res = check_create(mtd, buf, bd); |
61b03bd7 | 1150 | |
1da177e4 | 1151 | /* Prevent the bbt regions from erasing / writing */ |
e0c7d767 | 1152 | mark_bbt_region(mtd, td); |
1da177e4 | 1153 | if (md) |
e0c7d767 | 1154 | mark_bbt_region(mtd, md); |
61b03bd7 | 1155 | |
e0c7d767 | 1156 | vfree(buf); |
1da177e4 LT |
1157 | return res; |
1158 | } | |
1159 | ||
1da177e4 | 1160 | /** |
61b03bd7 | 1161 | * nand_update_bbt - [NAND Interface] update bad block table(s) |
8b6e50c9 BN |
1162 | * @mtd: MTD device structure |
1163 | * @offs: the offset of the newly marked block | |
1da177e4 | 1164 | * |
8b6e50c9 BN |
1165 | * The function updates the bad block table(s). |
1166 | */ | |
e0c7d767 | 1167 | int nand_update_bbt(struct mtd_info *mtd, loff_t offs) |
1da177e4 LT |
1168 | { |
1169 | struct nand_chip *this = mtd->priv; | |
1196ac5a | 1170 | int len, res = 0; |
1da177e4 LT |
1171 | int chip, chipsel; |
1172 | uint8_t *buf; | |
1173 | struct nand_bbt_descr *td = this->bbt_td; | |
1174 | struct nand_bbt_descr *md = this->bbt_md; | |
1175 | ||
1176 | if (!this->bbt || !td) | |
1177 | return -EINVAL; | |
1178 | ||
1da177e4 LT |
1179 | /* Allocate a temporary buffer for one eraseblock incl. oob */ |
1180 | len = (1 << this->bbt_erase_shift); | |
1181 | len += (len >> this->page_shift) * mtd->oobsize; | |
e0c7d767 | 1182 | buf = kmalloc(len, GFP_KERNEL); |
0870066d | 1183 | if (!buf) |
1da177e4 | 1184 | return -ENOMEM; |
61b03bd7 | 1185 | |
8b6e50c9 | 1186 | /* Do we have a bbt per chip? */ |
1da177e4 | 1187 | if (td->options & NAND_BBT_PERCHIP) { |
e0c7d767 | 1188 | chip = (int)(offs >> this->chip_shift); |
1da177e4 LT |
1189 | chipsel = chip; |
1190 | } else { | |
1191 | chip = 0; | |
1192 | chipsel = -1; | |
1193 | } | |
1194 | ||
1195 | td->version[chip]++; | |
1196 | if (md) | |
61b03bd7 | 1197 | md->version[chip]++; |
1da177e4 | 1198 | |
8b6e50c9 | 1199 | /* Write the bad block table to the device? */ |
1196ac5a | 1200 | if (td->options & NAND_BBT_WRITE) { |
e0c7d767 | 1201 | res = write_bbt(mtd, buf, td, md, chipsel); |
1da177e4 LT |
1202 | if (res < 0) |
1203 | goto out; | |
1204 | } | |
8b6e50c9 | 1205 | /* Write the mirror bad block table to the device? */ |
1196ac5a | 1206 | if (md && (md->options & NAND_BBT_WRITE)) { |
e0c7d767 | 1207 | res = write_bbt(mtd, buf, md, td, chipsel); |
1da177e4 LT |
1208 | } |
1209 | ||
e0c7d767 DW |
1210 | out: |
1211 | kfree(buf); | |
1da177e4 LT |
1212 | return res; |
1213 | } | |
1214 | ||
8b6e50c9 BN |
1215 | /* |
1216 | * Define some generic bad / good block scan pattern which are used | |
1217 | * while scanning a device for factory marked good / bad blocks. | |
1218 | */ | |
1da177e4 LT |
1219 | static uint8_t scan_ff_pattern[] = { 0xff, 0xff }; |
1220 | ||
1da177e4 LT |
1221 | static uint8_t scan_agand_pattern[] = { 0x1C, 0x71, 0xC7, 0x1C, 0x71, 0xC7 }; |
1222 | ||
1223 | static struct nand_bbt_descr agand_flashbased = { | |
1224 | .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES, | |
1225 | .offs = 0x20, | |
1226 | .len = 6, | |
1227 | .pattern = scan_agand_pattern | |
1228 | }; | |
1229 | ||
7854d3f7 | 1230 | /* Generic flash bbt descriptors */ |
1da177e4 LT |
1231 | static uint8_t bbt_pattern[] = {'B', 'b', 't', '0' }; |
1232 | static uint8_t mirror_pattern[] = {'1', 't', 'b', 'B' }; | |
1233 | ||
1234 | static struct nand_bbt_descr bbt_main_descr = { | |
61b03bd7 | 1235 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
1da177e4 LT |
1236 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP, |
1237 | .offs = 8, | |
1238 | .len = 4, | |
1239 | .veroffs = 12, | |
1240 | .maxblocks = 4, | |
1241 | .pattern = bbt_pattern | |
1242 | }; | |
1243 | ||
1244 | static struct nand_bbt_descr bbt_mirror_descr = { | |
61b03bd7 | 1245 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE |
1da177e4 LT |
1246 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP, |
1247 | .offs = 8, | |
1248 | .len = 4, | |
1249 | .veroffs = 12, | |
1250 | .maxblocks = 4, | |
1251 | .pattern = mirror_pattern | |
1252 | }; | |
1253 | ||
7cba7b14 SAS |
1254 | static struct nand_bbt_descr bbt_main_no_bbt_descr = { |
1255 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE | |
1256 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP | |
1257 | | NAND_BBT_NO_OOB, | |
1258 | .len = 4, | |
1259 | .veroffs = 4, | |
1260 | .maxblocks = 4, | |
1261 | .pattern = bbt_pattern | |
1262 | }; | |
1263 | ||
1264 | static struct nand_bbt_descr bbt_mirror_no_bbt_descr = { | |
1265 | .options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE | |
1266 | | NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP | |
1267 | | NAND_BBT_NO_OOB, | |
1268 | .len = 4, | |
1269 | .veroffs = 4, | |
1270 | .maxblocks = 4, | |
1271 | .pattern = mirror_pattern | |
1272 | }; | |
1273 | ||
58373ff0 | 1274 | /** |
7854d3f7 | 1275 | * nand_create_default_bbt_descr - [INTERN] Creates a BBT descriptor structure |
8b6e50c9 | 1276 | * @this: NAND chip to create descriptor for |
58373ff0 BN |
1277 | * |
1278 | * This function allocates and initializes a nand_bbt_descr for BBM detection | |
1279 | * based on the properties of "this". The new descriptor is stored in | |
1280 | * this->badblock_pattern. Thus, this->badblock_pattern should be NULL when | |
1281 | * passed to this function. | |
58373ff0 BN |
1282 | */ |
1283 | static int nand_create_default_bbt_descr(struct nand_chip *this) | |
1284 | { | |
1285 | struct nand_bbt_descr *bd; | |
1286 | if (this->badblock_pattern) { | |
d0370219 | 1287 | pr_warn("BBT descr already allocated; not replacing\n"); |
58373ff0 BN |
1288 | return -EINVAL; |
1289 | } | |
1290 | bd = kzalloc(sizeof(*bd), GFP_KERNEL); | |
0870066d | 1291 | if (!bd) |
58373ff0 | 1292 | return -ENOMEM; |
5fb1549d | 1293 | bd->options = this->bbt_options; |
58373ff0 BN |
1294 | bd->offs = this->badblockpos; |
1295 | bd->len = (this->options & NAND_BUSWIDTH_16) ? 2 : 1; | |
1296 | bd->pattern = scan_ff_pattern; | |
1297 | bd->options |= NAND_BBT_DYNAMICSTRUCT; | |
1298 | this->badblock_pattern = bd; | |
1299 | return 0; | |
1300 | } | |
1301 | ||
1da177e4 | 1302 | /** |
61b03bd7 | 1303 | * nand_default_bbt - [NAND Interface] Select a default bad block table for the device |
8b6e50c9 | 1304 | * @mtd: MTD device structure |
1da177e4 | 1305 | * |
8b6e50c9 BN |
1306 | * This function selects the default bad block table support for the device and |
1307 | * calls the nand_scan_bbt function. | |
1308 | */ | |
e0c7d767 | 1309 | int nand_default_bbt(struct mtd_info *mtd) |
1da177e4 LT |
1310 | { |
1311 | struct nand_chip *this = mtd->priv; | |
61b03bd7 | 1312 | |
8b6e50c9 BN |
1313 | /* |
1314 | * Default for AG-AND. We must use a flash based bad block table as the | |
1315 | * devices have factory marked _good_ blocks. Erasing those blocks | |
1316 | * leads to loss of the good / bad information, so we _must_ store this | |
1317 | * information in a good / bad table during startup. | |
e0c7d767 | 1318 | */ |
1da177e4 LT |
1319 | if (this->options & NAND_IS_AND) { |
1320 | /* Use the default pattern descriptors */ | |
61b03bd7 | 1321 | if (!this->bbt_td) { |
1da177e4 LT |
1322 | this->bbt_td = &bbt_main_descr; |
1323 | this->bbt_md = &bbt_mirror_descr; | |
61b03bd7 | 1324 | } |
bb9ebd4e | 1325 | this->bbt_options |= NAND_BBT_USE_FLASH; |
e0c7d767 | 1326 | return nand_scan_bbt(mtd, &agand_flashbased); |
1da177e4 | 1327 | } |
61b03bd7 | 1328 | |
8b6e50c9 | 1329 | /* Is a flash based bad block table requested? */ |
bb9ebd4e | 1330 | if (this->bbt_options & NAND_BBT_USE_FLASH) { |
61b03bd7 TG |
1331 | /* Use the default pattern descriptors */ |
1332 | if (!this->bbt_td) { | |
a40f7341 | 1333 | if (this->bbt_options & NAND_BBT_NO_OOB) { |
7cba7b14 SAS |
1334 | this->bbt_td = &bbt_main_no_bbt_descr; |
1335 | this->bbt_md = &bbt_mirror_no_bbt_descr; | |
1336 | } else { | |
1337 | this->bbt_td = &bbt_main_descr; | |
1338 | this->bbt_md = &bbt_mirror_descr; | |
1339 | } | |
1da177e4 | 1340 | } |
1da177e4 LT |
1341 | } else { |
1342 | this->bbt_td = NULL; | |
1343 | this->bbt_md = NULL; | |
1da177e4 | 1344 | } |
a2f812df BN |
1345 | |
1346 | if (!this->badblock_pattern) | |
1347 | nand_create_default_bbt_descr(this); | |
1348 | ||
e0c7d767 | 1349 | return nand_scan_bbt(mtd, this->badblock_pattern); |
1da177e4 LT |
1350 | } |
1351 | ||
1352 | /** | |
61b03bd7 | 1353 | * nand_isbad_bbt - [NAND Interface] Check if a block is bad |
8b6e50c9 BN |
1354 | * @mtd: MTD device structure |
1355 | * @offs: offset in the device | |
1356 | * @allowbbt: allow access to bad block table region | |
1357 | */ | |
e0c7d767 | 1358 | int nand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt) |
1da177e4 LT |
1359 | { |
1360 | struct nand_chip *this = mtd->priv; | |
1361 | int block; | |
e0c7d767 | 1362 | uint8_t res; |
61b03bd7 | 1363 | |
1da177e4 | 1364 | /* Get block number * 2 */ |
e0c7d767 | 1365 | block = (int)(offs >> (this->bbt_erase_shift - 1)); |
1da177e4 LT |
1366 | res = (this->bbt[block >> 3] >> (block & 0x06)) & 0x03; |
1367 | ||
289c0522 BN |
1368 | pr_debug("nand_isbad_bbt(): bbt info for offs 0x%08x: " |
1369 | "(block %d) 0x%02x\n", | |
1370 | (unsigned int)offs, block >> 1, res); | |
1da177e4 LT |
1371 | |
1372 | switch ((int)res) { | |
e0c7d767 DW |
1373 | case 0x00: |
1374 | return 0; | |
1375 | case 0x01: | |
1376 | return 1; | |
1377 | case 0x02: | |
1378 | return allowbbt ? 0 : 1; | |
1da177e4 LT |
1379 | } |
1380 | return 1; | |
1381 | } | |
1382 | ||
e0c7d767 DW |
1383 | EXPORT_SYMBOL(nand_scan_bbt); |
1384 | EXPORT_SYMBOL(nand_default_bbt); |