1 | /* |
2 | * sharpslpart.c - MTD partition parser for NAND flash using the SHARP FTL |
3 | * for logical addressing, as used on the PXA models of the SHARP SL Series. |
4 | * |
5 | * Copyright (C) 2017 Andrea Adami <andrea.adami@gmail.com> |
6 | * |
7 | * Based on SHARP GPL 2.4 sources: |
8 | * http://support.ezaurus.com/developer/source/source_dl.asp |
9 | * drivers/mtd/nand/sharp_sl_logical.c |
10 | * linux/include/asm-arm/sharp_nand_logical.h |
11 | * |
12 | * Copyright (C) 2002 SHARP |
13 | * |
14 | * This program is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * This program is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | */ |
25 | |
26 | #include <linux/kernel.h> |
27 | #include <linux/slab.h> |
28 | #include <linux/module.h> |
29 | #include <linux/types.h> |
30 | #include <linux/bitops.h> |
31 | #include <linux/sizes.h> |
32 | #include <linux/mtd/mtd.h> |
33 | #include <linux/mtd/partitions.h> |
34 | |
35 | /* oob structure */ |
36 | #define NAND_NOOB_LOGADDR_00 8 |
37 | #define NAND_NOOB_LOGADDR_01 9 |
38 | #define NAND_NOOB_LOGADDR_10 10 |
39 | #define NAND_NOOB_LOGADDR_11 11 |
40 | #define NAND_NOOB_LOGADDR_20 12 |
41 | #define NAND_NOOB_LOGADDR_21 13 |
42 | |
43 | #define BLOCK_IS_RESERVED 0xffff |
44 | #define BLOCK_UNMASK_COMPLEMENT 1 |
45 | |
46 | /* factory defaults */ |
47 | #define SHARPSL_NAND_PARTS 3 |
48 | #define SHARPSL_FTL_PART_SIZE (7 * SZ_1M) |
49 | #define SHARPSL_PARTINFO1_LADDR 0x00060000 |
50 | #define SHARPSL_PARTINFO2_LADDR 0x00064000 |
51 | |
52 | #define BOOT_MAGIC 0x424f4f54 |
53 | #define FSRO_MAGIC 0x4653524f |
54 | #define FSRW_MAGIC 0x46535257 |
55 | |
56 | /** |
57 | * struct sharpsl_ftl - Sharp FTL Logical Table |
58 | * @logmax: number of logical blocks |
59 | * @log2phy: the logical-to-physical table |
60 | * |
61 | * Structure containing the logical-to-physical translation table |
62 | * used by the SHARP SL FTL. |
63 | */ |
64 | struct sharpsl_ftl { |
65 | unsigned int logmax; |
66 | unsigned int *log2phy; |
67 | }; |
68 | |
69 | /* verify that the OOB bytes 8 to 15 are free and available for the FTL */ |
70 | static int sharpsl_nand_check_ooblayout(struct mtd_info *mtd) |
71 | { |
72 | u8 freebytes = 0; |
73 | int section = 0; |
74 | |
75 | while (true) { |
76 | struct mtd_oob_region oobfree = { }; |
77 | int ret, i; |
78 | |
79 | ret = mtd_ooblayout_free(mtd, section: section++, oobfree: &oobfree); |
80 | if (ret) |
81 | break; |
82 | |
83 | if (!oobfree.length || oobfree.offset > 15 || |
84 | (oobfree.offset + oobfree.length) < 8) |
85 | continue; |
86 | |
87 | i = oobfree.offset >= 8 ? oobfree.offset : 8; |
88 | for (; i < oobfree.offset + oobfree.length && i < 16; i++) |
89 | freebytes |= BIT(i - 8); |
90 | |
91 | if (freebytes == 0xff) |
92 | return 0; |
93 | } |
94 | |
95 | return -ENOTSUPP; |
96 | } |
97 | |
98 | static int sharpsl_nand_read_oob(struct mtd_info *mtd, loff_t offs, u8 *buf) |
99 | { |
100 | struct mtd_oob_ops ops = { }; |
101 | int ret; |
102 | |
103 | ops.mode = MTD_OPS_PLACE_OOB; |
104 | ops.ooblen = mtd->oobsize; |
105 | ops.oobbuf = buf; |
106 | |
107 | ret = mtd_read_oob(mtd, from: offs, ops: &ops); |
108 | if (ret != 0 || mtd->oobsize != ops.oobretlen) |
109 | return -1; |
110 | |
111 | return 0; |
112 | } |
113 | |
114 | /* |
115 | * The logical block number assigned to a physical block is stored in the OOB |
116 | * of the first page, in 3 16-bit copies with the following layout: |
117 | * |
118 | * 01234567 89abcdef |
119 | * -------- -------- |
120 | * ECC BB xyxyxy |
121 | * |
122 | * When reading we check that the first two copies agree. |
123 | * In case of error, matching is tried using the following pairs. |
124 | * Reserved values 0xffff mean the block is kept for wear leveling. |
125 | * |
126 | * 01234567 89abcdef |
127 | * -------- -------- |
128 | * ECC BB xyxy oob[8]==oob[10] && oob[9]==oob[11] -> byte0=8 byte1=9 |
129 | * ECC BB xyxy oob[10]==oob[12] && oob[11]==oob[13] -> byte0=10 byte1=11 |
130 | * ECC BB xy xy oob[12]==oob[8] && oob[13]==oob[9] -> byte0=12 byte1=13 |
131 | */ |
132 | static int sharpsl_nand_get_logical_num(u8 *oob) |
133 | { |
134 | u16 us; |
135 | int good0, good1; |
136 | |
137 | if (oob[NAND_NOOB_LOGADDR_00] == oob[NAND_NOOB_LOGADDR_10] && |
138 | oob[NAND_NOOB_LOGADDR_01] == oob[NAND_NOOB_LOGADDR_11]) { |
139 | good0 = NAND_NOOB_LOGADDR_00; |
140 | good1 = NAND_NOOB_LOGADDR_01; |
141 | } else if (oob[NAND_NOOB_LOGADDR_10] == oob[NAND_NOOB_LOGADDR_20] && |
142 | oob[NAND_NOOB_LOGADDR_11] == oob[NAND_NOOB_LOGADDR_21]) { |
143 | good0 = NAND_NOOB_LOGADDR_10; |
144 | good1 = NAND_NOOB_LOGADDR_11; |
145 | } else if (oob[NAND_NOOB_LOGADDR_20] == oob[NAND_NOOB_LOGADDR_00] && |
146 | oob[NAND_NOOB_LOGADDR_21] == oob[NAND_NOOB_LOGADDR_01]) { |
147 | good0 = NAND_NOOB_LOGADDR_20; |
148 | good1 = NAND_NOOB_LOGADDR_21; |
149 | } else { |
150 | return -EINVAL; |
151 | } |
152 | |
153 | us = oob[good0] | oob[good1] << 8; |
154 | |
155 | /* parity check */ |
156 | if (hweight16(us) & BLOCK_UNMASK_COMPLEMENT) |
157 | return -EINVAL; |
158 | |
159 | /* reserved */ |
160 | if (us == BLOCK_IS_RESERVED) |
161 | return BLOCK_IS_RESERVED; |
162 | |
163 | return (us >> 1) & GENMASK(9, 0); |
164 | } |
165 | |
166 | static int sharpsl_nand_init_ftl(struct mtd_info *mtd, struct sharpsl_ftl *ftl) |
167 | { |
168 | unsigned int block_num, phymax; |
169 | int i, ret, log_num; |
170 | loff_t block_adr; |
171 | u8 *oob; |
172 | |
173 | oob = kzalloc(size: mtd->oobsize, GFP_KERNEL); |
174 | if (!oob) |
175 | return -ENOMEM; |
176 | |
177 | phymax = mtd_div_by_eb(SHARPSL_FTL_PART_SIZE, mtd); |
178 | |
179 | /* FTL reserves 5% of the blocks + 1 spare */ |
180 | ftl->logmax = ((phymax * 95) / 100) - 1; |
181 | |
182 | ftl->log2phy = kmalloc_array(n: ftl->logmax, size: sizeof(*ftl->log2phy), |
183 | GFP_KERNEL); |
184 | if (!ftl->log2phy) { |
185 | ret = -ENOMEM; |
186 | goto exit; |
187 | } |
188 | |
189 | /* initialize ftl->log2phy */ |
190 | for (i = 0; i < ftl->logmax; i++) |
191 | ftl->log2phy[i] = UINT_MAX; |
192 | |
193 | /* create physical-logical table */ |
194 | for (block_num = 0; block_num < phymax; block_num++) { |
195 | block_adr = (loff_t)block_num * mtd->erasesize; |
196 | |
197 | if (mtd_block_isbad(mtd, ofs: block_adr)) |
198 | continue; |
199 | |
200 | if (sharpsl_nand_read_oob(mtd, offs: block_adr, buf: oob)) |
201 | continue; |
202 | |
203 | /* get logical block */ |
204 | log_num = sharpsl_nand_get_logical_num(oob); |
205 | |
206 | /* cut-off errors and skip the out-of-range values */ |
207 | if (log_num > 0 && log_num < ftl->logmax) { |
208 | if (ftl->log2phy[log_num] == UINT_MAX) |
209 | ftl->log2phy[log_num] = block_num; |
210 | } |
211 | } |
212 | |
213 | pr_info("Sharp SL FTL: %d blocks used (%d logical, %d reserved)\n" , |
214 | phymax, ftl->logmax, phymax - ftl->logmax); |
215 | |
216 | ret = 0; |
217 | exit: |
218 | kfree(objp: oob); |
219 | return ret; |
220 | } |
221 | |
222 | static void sharpsl_nand_cleanup_ftl(struct sharpsl_ftl *ftl) |
223 | { |
224 | kfree(objp: ftl->log2phy); |
225 | } |
226 | |
227 | static int sharpsl_nand_read_laddr(struct mtd_info *mtd, |
228 | loff_t from, |
229 | size_t len, |
230 | void *buf, |
231 | struct sharpsl_ftl *ftl) |
232 | { |
233 | unsigned int log_num, final_log_num; |
234 | unsigned int block_num; |
235 | loff_t block_adr; |
236 | loff_t block_ofs; |
237 | size_t retlen; |
238 | int err; |
239 | |
240 | log_num = mtd_div_by_eb(sz: (u32)from, mtd); |
241 | final_log_num = mtd_div_by_eb(sz: ((u32)from + len - 1), mtd); |
242 | |
243 | if (len <= 0 || log_num >= ftl->logmax || final_log_num > log_num) |
244 | return -EINVAL; |
245 | |
246 | block_num = ftl->log2phy[log_num]; |
247 | block_adr = (loff_t)block_num * mtd->erasesize; |
248 | block_ofs = mtd_mod_by_eb(sz: (u32)from, mtd); |
249 | |
250 | err = mtd_read(mtd, from: block_adr + block_ofs, len, retlen: &retlen, buf); |
251 | /* Ignore corrected ECC errors */ |
252 | if (mtd_is_bitflip(err)) |
253 | err = 0; |
254 | |
255 | if (!err && retlen != len) |
256 | err = -EIO; |
257 | |
258 | if (err) |
259 | pr_err("sharpslpart: error, read failed at %#llx\n" , |
260 | block_adr + block_ofs); |
261 | |
262 | return err; |
263 | } |
264 | |
265 | /* |
266 | * MTD Partition Parser |
267 | * |
268 | * Sample values read from SL-C860 |
269 | * |
270 | * # cat /proc/mtd |
271 | * dev: size erasesize name |
272 | * mtd0: 006d0000 00020000 "Filesystem" |
273 | * mtd1: 00700000 00004000 "smf" |
274 | * mtd2: 03500000 00004000 "root" |
275 | * mtd3: 04400000 00004000 "home" |
276 | * |
277 | * PARTITIONINFO1 |
278 | * 0x00060000: 00 00 00 00 00 00 70 00 42 4f 4f 54 00 00 00 00 ......p.BOOT.... |
279 | * 0x00060010: 00 00 70 00 00 00 c0 03 46 53 52 4f 00 00 00 00 ..p.....FSRO.... |
280 | * 0x00060020: 00 00 c0 03 00 00 00 04 46 53 52 57 00 00 00 00 ........FSRW.... |
281 | */ |
282 | struct sharpsl_nand_partinfo { |
283 | __le32 start; |
284 | __le32 end; |
285 | __be32 magic; |
286 | u32 reserved; |
287 | }; |
288 | |
289 | static int sharpsl_nand_read_partinfo(struct mtd_info *master, |
290 | loff_t from, |
291 | size_t len, |
292 | struct sharpsl_nand_partinfo *buf, |
293 | struct sharpsl_ftl *ftl) |
294 | { |
295 | int ret; |
296 | |
297 | ret = sharpsl_nand_read_laddr(mtd: master, from, len, buf, ftl); |
298 | if (ret) |
299 | return ret; |
300 | |
301 | /* check for magics */ |
302 | if (be32_to_cpu(buf[0].magic) != BOOT_MAGIC || |
303 | be32_to_cpu(buf[1].magic) != FSRO_MAGIC || |
304 | be32_to_cpu(buf[2].magic) != FSRW_MAGIC) { |
305 | pr_err("sharpslpart: magic values mismatch\n" ); |
306 | return -EINVAL; |
307 | } |
308 | |
309 | /* fixup for hardcoded value 64 MiB (for older models) */ |
310 | buf[2].end = cpu_to_le32(master->size); |
311 | |
312 | /* extra sanity check */ |
313 | if (le32_to_cpu(buf[0].end) <= le32_to_cpu(buf[0].start) || |
314 | le32_to_cpu(buf[1].start) < le32_to_cpu(buf[0].end) || |
315 | le32_to_cpu(buf[1].end) <= le32_to_cpu(buf[1].start) || |
316 | le32_to_cpu(buf[2].start) < le32_to_cpu(buf[1].end) || |
317 | le32_to_cpu(buf[2].end) <= le32_to_cpu(buf[2].start)) { |
318 | pr_err("sharpslpart: partition sizes mismatch\n" ); |
319 | return -EINVAL; |
320 | } |
321 | |
322 | return 0; |
323 | } |
324 | |
325 | static int sharpsl_parse_mtd_partitions(struct mtd_info *master, |
326 | const struct mtd_partition **pparts, |
327 | struct mtd_part_parser_data *data) |
328 | { |
329 | struct sharpsl_ftl ftl; |
330 | struct sharpsl_nand_partinfo buf[SHARPSL_NAND_PARTS]; |
331 | struct mtd_partition *sharpsl_nand_parts; |
332 | int err; |
333 | |
334 | /* check that OOB bytes 8 to 15 used by the FTL are actually free */ |
335 | err = sharpsl_nand_check_ooblayout(mtd: master); |
336 | if (err) |
337 | return err; |
338 | |
339 | /* init logical mgmt (FTL) */ |
340 | err = sharpsl_nand_init_ftl(mtd: master, ftl: &ftl); |
341 | if (err) |
342 | return err; |
343 | |
344 | /* read and validate first partition table */ |
345 | pr_info("sharpslpart: try reading first partition table\n" ); |
346 | err = sharpsl_nand_read_partinfo(master, |
347 | SHARPSL_PARTINFO1_LADDR, |
348 | len: sizeof(buf), buf, ftl: &ftl); |
349 | if (err) { |
350 | /* fallback: read second partition table */ |
351 | pr_warn("sharpslpart: first partition table is invalid, retry using the second\n" ); |
352 | err = sharpsl_nand_read_partinfo(master, |
353 | SHARPSL_PARTINFO2_LADDR, |
354 | len: sizeof(buf), buf, ftl: &ftl); |
355 | } |
356 | |
357 | /* cleanup logical mgmt (FTL) */ |
358 | sharpsl_nand_cleanup_ftl(ftl: &ftl); |
359 | |
360 | if (err) { |
361 | pr_err("sharpslpart: both partition tables are invalid\n" ); |
362 | return err; |
363 | } |
364 | |
365 | sharpsl_nand_parts = kcalloc(SHARPSL_NAND_PARTS, |
366 | size: sizeof(*sharpsl_nand_parts), |
367 | GFP_KERNEL); |
368 | if (!sharpsl_nand_parts) |
369 | return -ENOMEM; |
370 | |
371 | /* original names */ |
372 | sharpsl_nand_parts[0].name = "smf" ; |
373 | sharpsl_nand_parts[0].offset = le32_to_cpu(buf[0].start); |
374 | sharpsl_nand_parts[0].size = le32_to_cpu(buf[0].end) - |
375 | le32_to_cpu(buf[0].start); |
376 | |
377 | sharpsl_nand_parts[1].name = "root" ; |
378 | sharpsl_nand_parts[1].offset = le32_to_cpu(buf[1].start); |
379 | sharpsl_nand_parts[1].size = le32_to_cpu(buf[1].end) - |
380 | le32_to_cpu(buf[1].start); |
381 | |
382 | sharpsl_nand_parts[2].name = "home" ; |
383 | sharpsl_nand_parts[2].offset = le32_to_cpu(buf[2].start); |
384 | sharpsl_nand_parts[2].size = le32_to_cpu(buf[2].end) - |
385 | le32_to_cpu(buf[2].start); |
386 | |
387 | *pparts = sharpsl_nand_parts; |
388 | return SHARPSL_NAND_PARTS; |
389 | } |
390 | |
391 | static struct mtd_part_parser sharpsl_mtd_parser = { |
392 | .parse_fn = sharpsl_parse_mtd_partitions, |
393 | .name = "sharpslpart" , |
394 | }; |
395 | module_mtd_part_parser(sharpsl_mtd_parser); |
396 | |
397 | MODULE_LICENSE("GPL" ); |
398 | MODULE_AUTHOR("Andrea Adami <andrea.adami@gmail.com>" ); |
399 | MODULE_DESCRIPTION("MTD partitioning for NAND flash on Sharp SL Series" ); |
400 | |