1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2014
4 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
5 */
6 #include <common.h>
7 #include <env.h>
8 #include <log.h>
9 #include <malloc.h>
10 #include <dm/device.h>
11 #include <dm/uclass-internal.h>
12 #include <linux/err.h>
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/partitions.h>
15 #include <asm/global_data.h>
16 #include <mtd.h>
17
18 #define MTD_NAME_MAX_LEN 20
19
20 void board_mtdparts_default(const char **mtdids, const char **mtdparts);
21
get_mtdids(void)22 static const char *get_mtdids(void)
23 {
24 __maybe_unused const char *mtdparts = NULL;
25 const char *mtdids = env_get("mtdids");
26
27 if (mtdids)
28 return mtdids;
29
30 #if defined(CONFIG_SYS_MTDPARTS_RUNTIME)
31 board_mtdparts_default(&mtdids, &mtdparts);
32 #elif defined(MTDIDS_DEFAULT)
33 mtdids = MTDIDS_DEFAULT;
34 #elif defined(CONFIG_MTDIDS_DEFAULT)
35 mtdids = CONFIG_MTDIDS_DEFAULT;
36 #endif
37
38 if (mtdids)
39 env_set("mtdids", mtdids);
40
41 return mtdids;
42 }
43
44 /**
45 * mtd_search_alternate_name - Search an alternate name for @mtdname thanks to
46 * the mtdids legacy environment variable.
47 *
48 * The mtdids string is a list of comma-separated 'dev_id=mtd_id' tupples.
49 * Check if one of the mtd_id matches mtdname, in this case save dev_id in
50 * altname.
51 *
52 * @mtdname: Current MTD device name
53 * @altname: Alternate name to return
54 * @max_len: Length of the alternate name buffer
55 *
56 * @return 0 on success, an error otherwise.
57 */
mtd_search_alternate_name(const char * mtdname,char * altname,unsigned int max_len)58 int mtd_search_alternate_name(const char *mtdname, char *altname,
59 unsigned int max_len)
60 {
61 const char *mtdids, *equal, *comma, *dev_id, *mtd_id;
62 int dev_id_len, mtd_id_len;
63
64 mtdids = get_mtdids();
65 if (!mtdids)
66 return -EINVAL;
67
68 do {
69 /* Find the '=' sign */
70 dev_id = mtdids;
71 equal = strchr(dev_id, '=');
72 if (!equal)
73 break;
74 dev_id_len = equal - mtdids;
75 mtd_id = equal + 1;
76
77 /* Find the end of the tupple */
78 comma = strchr(mtdids, ',');
79 if (comma)
80 mtd_id_len = comma - mtd_id;
81 else
82 mtd_id_len = &mtdids[strlen(mtdids)] - mtd_id + 1;
83
84 if (!dev_id_len || !mtd_id_len)
85 return -EINVAL;
86
87 if (dev_id_len + 1 > max_len)
88 continue;
89
90 /* Compare the name we search with the current mtd_id */
91 if (!strncmp(mtdname, mtd_id, mtd_id_len)) {
92 strncpy(altname, dev_id, dev_id_len);
93 altname[dev_id_len] = 0;
94
95 return 0;
96 }
97
98 /* Go to the next tupple */
99 mtdids = comma + 1;
100 } while (comma);
101
102 return -EINVAL;
103 }
104
105 #if IS_ENABLED(CONFIG_DM_MTD)
mtd_probe_uclass_mtd_devs(void)106 static void mtd_probe_uclass_mtd_devs(void)
107 {
108 struct udevice *dev;
109 int idx = 0;
110
111 /* Probe devices with DM compliant drivers */
112 while (!uclass_find_device(UCLASS_MTD, idx, &dev) && dev) {
113 mtd_probe(dev);
114 idx++;
115 }
116 }
117 #else
mtd_probe_uclass_mtd_devs(void)118 static void mtd_probe_uclass_mtd_devs(void) { }
119 #endif
120
121 #if defined(CONFIG_MTD_PARTITIONS)
122
123 #define MTDPARTS_MAXLEN 512
124
get_mtdparts(void)125 static const char *get_mtdparts(void)
126 {
127 __maybe_unused const char *mtdids = NULL;
128 static char tmp_parts[MTDPARTS_MAXLEN];
129 const char *mtdparts = NULL;
130
131 if (gd->flags & GD_FLG_ENV_READY)
132 mtdparts = env_get("mtdparts");
133 else if (env_get_f("mtdparts", tmp_parts, sizeof(tmp_parts)) != -1)
134 mtdparts = tmp_parts;
135
136 if (mtdparts)
137 return mtdparts;
138
139 #if defined(CONFIG_SYS_MTDPARTS_RUNTIME)
140 board_mtdparts_default(&mtdids, &mtdparts);
141 #elif defined(MTDPARTS_DEFAULT)
142 mtdparts = MTDPARTS_DEFAULT;
143 #elif defined(CONFIG_MTDPARTS_DEFAULT)
144 mtdparts = CONFIG_MTDPARTS_DEFAULT;
145 #endif
146
147 if (mtdparts)
148 env_set("mtdparts", mtdparts);
149
150 return mtdparts;
151 }
152
mtd_del_parts(struct mtd_info * mtd,bool quiet)153 static int mtd_del_parts(struct mtd_info *mtd, bool quiet)
154 {
155 int ret;
156
157 if (!mtd_has_partitions(mtd))
158 return 0;
159
160 /* do not delete partitions if they are in use. */
161 if (mtd_partitions_used(mtd)) {
162 if (!quiet)
163 printf("\"%s\" partitions still in use, can't delete them\n",
164 mtd->name);
165 return -EACCES;
166 }
167
168 ret = del_mtd_partitions(mtd);
169 if (ret)
170 return ret;
171
172 return 1;
173 }
174
175 static bool mtd_del_all_parts_failed;
176
mtd_del_all_parts(void)177 static void mtd_del_all_parts(void)
178 {
179 struct mtd_info *mtd;
180 int ret = 0;
181
182 mtd_del_all_parts_failed = false;
183
184 /*
185 * It is not safe to remove entries from the mtd_for_each_device loop
186 * as it uses idr indexes and the partitions removal is done in bulk
187 * (all partitions of one device at the same time), so break and
188 * iterate from start each time a new partition is found and deleted.
189 */
190 do {
191 mtd_for_each_device(mtd) {
192 ret = mtd_del_parts(mtd, false);
193 if (ret > 0)
194 break;
195 else if (ret < 0)
196 mtd_del_all_parts_failed = true;
197 }
198 } while (ret > 0);
199 }
200
mtd_probe_devices(void)201 int mtd_probe_devices(void)
202 {
203 static char *old_mtdparts;
204 static char *old_mtdids;
205 const char *mtdparts = get_mtdparts();
206 const char *mtdids = get_mtdids();
207 const char *mtdparts_next = mtdparts;
208 struct mtd_info *mtd;
209
210 mtd_probe_uclass_mtd_devs();
211
212 /*
213 * Check if mtdparts/mtdids changed, if the MTD dev list was updated
214 * or if our previous attempt to delete existing partititions failed.
215 * In any of these cases we want to update the partitions, otherwise,
216 * everything is up-to-date and we can return 0 directly.
217 */
218 if ((!mtdparts && !old_mtdparts && !mtdids && !old_mtdids) ||
219 (mtdparts && old_mtdparts && mtdids && old_mtdids &&
220 !mtd_dev_list_updated() && !mtd_del_all_parts_failed &&
221 !strcmp(mtdparts, old_mtdparts) &&
222 !strcmp(mtdids, old_mtdids)))
223 return 0;
224
225 /* Update the local copy of mtdparts */
226 free(old_mtdparts);
227 free(old_mtdids);
228 old_mtdparts = strdup(mtdparts);
229 old_mtdids = strdup(mtdids);
230
231 /*
232 * Remove all old parts. Note that partition removal can fail in case
233 * one of the partition is still being used by an MTD user, so this
234 * does not guarantee that all old partitions are gone.
235 */
236 mtd_del_all_parts();
237
238 /*
239 * Call mtd_dev_list_updated() to clear updates generated by our own
240 * parts removal loop.
241 */
242 mtd_dev_list_updated();
243
244 /* If either mtdparts or mtdids is empty, then exit */
245 if (!mtdparts || !mtdids)
246 return 0;
247
248 /* Start the parsing by ignoring the extra 'mtdparts=' prefix, if any */
249 if (!strncmp(mtdparts, "mtdparts=", sizeof("mtdparts=") - 1))
250 mtdparts += 9;
251
252 /* For each MTD device in mtdparts */
253 for (; mtdparts[0] != '\0'; mtdparts = mtdparts_next) {
254 char mtd_name[MTD_NAME_MAX_LEN], *colon;
255 struct mtd_partition *parts;
256 unsigned int mtd_name_len;
257 int nparts, ret;
258
259 mtdparts_next = strchr(mtdparts, ';');
260 if (!mtdparts_next)
261 mtdparts_next = mtdparts + strlen(mtdparts);
262 else
263 mtdparts_next++;
264
265 colon = strchr(mtdparts, ':');
266 if (colon > mtdparts_next)
267 colon = NULL;
268
269 if (!colon) {
270 printf("Wrong mtdparts: %s\n", mtdparts);
271 return -EINVAL;
272 }
273
274 mtd_name_len = (unsigned int)(colon - mtdparts);
275 if (mtd_name_len + 1 > sizeof(mtd_name)) {
276 printf("MTD name too long: %s\n", mtdparts);
277 return -EINVAL;
278 }
279
280 strncpy(mtd_name, mtdparts, mtd_name_len);
281 mtd_name[mtd_name_len] = '\0';
282 /* Move the pointer forward (including the ':') */
283 mtdparts += mtd_name_len + 1;
284 mtd = get_mtd_device_nm(mtd_name);
285 if (IS_ERR_OR_NULL(mtd)) {
286 char linux_name[MTD_NAME_MAX_LEN];
287
288 /*
289 * The MTD device named "mtd_name" does not exist. Try
290 * to find a correspondance with an MTD device having
291 * the same type and number as defined in the mtdids.
292 */
293 debug("No device named %s\n", mtd_name);
294 ret = mtd_search_alternate_name(mtd_name, linux_name,
295 MTD_NAME_MAX_LEN);
296 if (!ret)
297 mtd = get_mtd_device_nm(linux_name);
298
299 /*
300 * If no device could be found, move the mtdparts
301 * pointer forward until the next set of partitions.
302 */
303 if (ret || IS_ERR_OR_NULL(mtd)) {
304 printf("Could not find a valid device for %s\n",
305 mtd_name);
306 mtdparts = mtdparts_next;
307 continue;
308 }
309 }
310
311 /*
312 * Call mtd_del_parts() again, even if it's already been called
313 * in mtd_del_all_parts(). We need to know if old partitions are
314 * still around (because they are still being used by someone),
315 * and if they are, we shouldn't create new partitions, so just
316 * skip this MTD device and try the next one.
317 */
318 ret = mtd_del_parts(mtd, true);
319 if (ret < 0)
320 continue;
321
322 /*
323 * Parse the MTD device partitions. It will update the mtdparts
324 * pointer, create an array of parts (that must be freed), and
325 * return the number of partition structures in the array.
326 */
327 ret = mtd_parse_partitions(mtd, &mtdparts, &parts, &nparts);
328 if (ret) {
329 printf("Could not parse device %s\n", mtd->name);
330 put_mtd_device(mtd);
331 return -EINVAL;
332 }
333
334 if (!nparts)
335 continue;
336
337 /* Create the new MTD partitions */
338 add_mtd_partitions(mtd, parts, nparts);
339
340 /* Free the structures allocated during the parsing */
341 mtd_free_parsed_partitions(parts, nparts);
342
343 put_mtd_device(mtd);
344 }
345
346 /*
347 * Call mtd_dev_list_updated() to clear updates generated by our own
348 * parts registration loop.
349 */
350 mtd_dev_list_updated();
351
352 return 0;
353 }
354 #else
mtd_probe_devices(void)355 int mtd_probe_devices(void)
356 {
357 mtd_probe_uclass_mtd_devs();
358
359 return 0;
360 }
361 #endif /* defined(CONFIG_MTD_PARTITIONS) */
362