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1da177e4 LT |
1 | /* |
2 | * $Id: mtdcore.c,v 1.44 2004/11/16 18:28:59 dwmw2 Exp $ | |
3 | * | |
4 | * Core registration and callback routines for MTD | |
5 | * drivers and users. | |
6 | * | |
7 | */ | |
8 | ||
9 | #include <linux/config.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/sched.h> | |
13 | #include <linux/ptrace.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/timer.h> | |
17 | #include <linux/major.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/ioctl.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/mtd/compatmac.h> | |
22 | #ifdef CONFIG_PROC_FS | |
23 | #include <linux/proc_fs.h> | |
24 | #endif | |
25 | ||
26 | #include <linux/mtd/mtd.h> | |
27 | ||
28 | /* These are exported solely for the purpose of mtd_blkdevs.c. You | |
29 | should not use them for _anything_ else */ | |
30 | DECLARE_MUTEX(mtd_table_mutex); | |
31 | struct mtd_info *mtd_table[MAX_MTD_DEVICES]; | |
32 | ||
33 | EXPORT_SYMBOL_GPL(mtd_table_mutex); | |
34 | EXPORT_SYMBOL_GPL(mtd_table); | |
35 | ||
36 | static LIST_HEAD(mtd_notifiers); | |
37 | ||
38 | /** | |
39 | * add_mtd_device - register an MTD device | |
40 | * @mtd: pointer to new MTD device info structure | |
41 | * | |
42 | * Add a device to the list of MTD devices present in the system, and | |
43 | * notify each currently active MTD 'user' of its arrival. Returns | |
44 | * zero on success or 1 on failure, which currently will only happen | |
45 | * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16) | |
46 | */ | |
47 | ||
48 | int add_mtd_device(struct mtd_info *mtd) | |
49 | { | |
50 | int i; | |
51 | ||
52 | down(&mtd_table_mutex); | |
53 | ||
54 | for (i=0; i < MAX_MTD_DEVICES; i++) | |
55 | if (!mtd_table[i]) { | |
56 | struct list_head *this; | |
57 | ||
58 | mtd_table[i] = mtd; | |
59 | mtd->index = i; | |
60 | mtd->usecount = 0; | |
61 | ||
62 | DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name); | |
63 | /* No need to get a refcount on the module containing | |
64 | the notifier, since we hold the mtd_table_mutex */ | |
65 | list_for_each(this, &mtd_notifiers) { | |
66 | struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list); | |
67 | not->add(mtd); | |
68 | } | |
69 | ||
70 | up(&mtd_table_mutex); | |
71 | /* We _know_ we aren't being removed, because | |
72 | our caller is still holding us here. So none | |
73 | of this try_ nonsense, and no bitching about it | |
74 | either. :) */ | |
75 | __module_get(THIS_MODULE); | |
76 | return 0; | |
77 | } | |
78 | ||
79 | up(&mtd_table_mutex); | |
80 | return 1; | |
81 | } | |
82 | ||
83 | /** | |
84 | * del_mtd_device - unregister an MTD device | |
85 | * @mtd: pointer to MTD device info structure | |
86 | * | |
87 | * Remove a device from the list of MTD devices present in the system, | |
88 | * and notify each currently active MTD 'user' of its departure. | |
89 | * Returns zero on success or 1 on failure, which currently will happen | |
90 | * if the requested device does not appear to be present in the list. | |
91 | */ | |
92 | ||
93 | int del_mtd_device (struct mtd_info *mtd) | |
94 | { | |
95 | int ret; | |
96 | ||
97 | down(&mtd_table_mutex); | |
98 | ||
99 | if (mtd_table[mtd->index] != mtd) { | |
100 | ret = -ENODEV; | |
101 | } else if (mtd->usecount) { | |
102 | printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", | |
103 | mtd->index, mtd->name, mtd->usecount); | |
104 | ret = -EBUSY; | |
105 | } else { | |
106 | struct list_head *this; | |
107 | ||
108 | /* No need to get a refcount on the module containing | |
109 | the notifier, since we hold the mtd_table_mutex */ | |
110 | list_for_each(this, &mtd_notifiers) { | |
111 | struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list); | |
112 | not->remove(mtd); | |
113 | } | |
114 | ||
115 | mtd_table[mtd->index] = NULL; | |
116 | ||
117 | module_put(THIS_MODULE); | |
118 | ret = 0; | |
119 | } | |
120 | ||
121 | up(&mtd_table_mutex); | |
122 | return ret; | |
123 | } | |
124 | ||
125 | /** | |
126 | * register_mtd_user - register a 'user' of MTD devices. | |
127 | * @new: pointer to notifier info structure | |
128 | * | |
129 | * Registers a pair of callbacks function to be called upon addition | |
130 | * or removal of MTD devices. Causes the 'add' callback to be immediately | |
131 | * invoked for each MTD device currently present in the system. | |
132 | */ | |
133 | ||
134 | void register_mtd_user (struct mtd_notifier *new) | |
135 | { | |
136 | int i; | |
137 | ||
138 | down(&mtd_table_mutex); | |
139 | ||
140 | list_add(&new->list, &mtd_notifiers); | |
141 | ||
142 | __module_get(THIS_MODULE); | |
143 | ||
144 | for (i=0; i< MAX_MTD_DEVICES; i++) | |
145 | if (mtd_table[i]) | |
146 | new->add(mtd_table[i]); | |
147 | ||
148 | up(&mtd_table_mutex); | |
149 | } | |
150 | ||
151 | /** | |
152 | * register_mtd_user - unregister a 'user' of MTD devices. | |
153 | * @new: pointer to notifier info structure | |
154 | * | |
155 | * Removes a callback function pair from the list of 'users' to be | |
156 | * notified upon addition or removal of MTD devices. Causes the | |
157 | * 'remove' callback to be immediately invoked for each MTD device | |
158 | * currently present in the system. | |
159 | */ | |
160 | ||
161 | int unregister_mtd_user (struct mtd_notifier *old) | |
162 | { | |
163 | int i; | |
164 | ||
165 | down(&mtd_table_mutex); | |
166 | ||
167 | module_put(THIS_MODULE); | |
168 | ||
169 | for (i=0; i< MAX_MTD_DEVICES; i++) | |
170 | if (mtd_table[i]) | |
171 | old->remove(mtd_table[i]); | |
172 | ||
173 | list_del(&old->list); | |
174 | up(&mtd_table_mutex); | |
175 | return 0; | |
176 | } | |
177 | ||
178 | ||
179 | /** | |
180 | * get_mtd_device - obtain a validated handle for an MTD device | |
181 | * @mtd: last known address of the required MTD device | |
182 | * @num: internal device number of the required MTD device | |
183 | * | |
184 | * Given a number and NULL address, return the num'th entry in the device | |
185 | * table, if any. Given an address and num == -1, search the device table | |
186 | * for a device with that address and return if it's still present. Given | |
187 | * both, return the num'th driver only if its address matches. Return NULL | |
188 | * if not. | |
189 | */ | |
190 | ||
191 | struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) | |
192 | { | |
193 | struct mtd_info *ret = NULL; | |
194 | int i; | |
195 | ||
196 | down(&mtd_table_mutex); | |
197 | ||
198 | if (num == -1) { | |
199 | for (i=0; i< MAX_MTD_DEVICES; i++) | |
200 | if (mtd_table[i] == mtd) | |
201 | ret = mtd_table[i]; | |
202 | } else if (num < MAX_MTD_DEVICES) { | |
203 | ret = mtd_table[num]; | |
204 | if (mtd && mtd != ret) | |
205 | ret = NULL; | |
206 | } | |
207 | ||
208 | if (ret && !try_module_get(ret->owner)) | |
209 | ret = NULL; | |
210 | ||
211 | if (ret) | |
212 | ret->usecount++; | |
213 | ||
214 | up(&mtd_table_mutex); | |
215 | return ret; | |
216 | } | |
217 | ||
218 | void put_mtd_device(struct mtd_info *mtd) | |
219 | { | |
220 | int c; | |
221 | ||
222 | down(&mtd_table_mutex); | |
223 | c = --mtd->usecount; | |
224 | up(&mtd_table_mutex); | |
225 | BUG_ON(c < 0); | |
226 | ||
227 | module_put(mtd->owner); | |
228 | } | |
229 | ||
230 | /* default_mtd_writev - default mtd writev method for MTD devices that | |
231 | * dont implement their own | |
232 | */ | |
233 | ||
234 | int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, | |
235 | unsigned long count, loff_t to, size_t *retlen) | |
236 | { | |
237 | unsigned long i; | |
238 | size_t totlen = 0, thislen; | |
239 | int ret = 0; | |
240 | ||
241 | if(!mtd->write) { | |
242 | ret = -EROFS; | |
243 | } else { | |
244 | for (i=0; i<count; i++) { | |
245 | if (!vecs[i].iov_len) | |
246 | continue; | |
247 | ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base); | |
248 | totlen += thislen; | |
249 | if (ret || thislen != vecs[i].iov_len) | |
250 | break; | |
251 | to += vecs[i].iov_len; | |
252 | } | |
253 | } | |
254 | if (retlen) | |
255 | *retlen = totlen; | |
256 | return ret; | |
257 | } | |
258 | ||
259 | ||
260 | /* default_mtd_readv - default mtd readv method for MTD devices that dont | |
261 | * implement their own | |
262 | */ | |
263 | ||
264 | int default_mtd_readv(struct mtd_info *mtd, struct kvec *vecs, | |
265 | unsigned long count, loff_t from, size_t *retlen) | |
266 | { | |
267 | unsigned long i; | |
268 | size_t totlen = 0, thislen; | |
269 | int ret = 0; | |
270 | ||
271 | if(!mtd->read) { | |
272 | ret = -EIO; | |
273 | } else { | |
274 | for (i=0; i<count; i++) { | |
275 | if (!vecs[i].iov_len) | |
276 | continue; | |
277 | ret = mtd->read(mtd, from, vecs[i].iov_len, &thislen, vecs[i].iov_base); | |
278 | totlen += thislen; | |
279 | if (ret || thislen != vecs[i].iov_len) | |
280 | break; | |
281 | from += vecs[i].iov_len; | |
282 | } | |
283 | } | |
284 | if (retlen) | |
285 | *retlen = totlen; | |
286 | return ret; | |
287 | } | |
288 | ||
289 | ||
290 | EXPORT_SYMBOL(add_mtd_device); | |
291 | EXPORT_SYMBOL(del_mtd_device); | |
292 | EXPORT_SYMBOL(get_mtd_device); | |
293 | EXPORT_SYMBOL(put_mtd_device); | |
294 | EXPORT_SYMBOL(register_mtd_user); | |
295 | EXPORT_SYMBOL(unregister_mtd_user); | |
296 | EXPORT_SYMBOL(default_mtd_writev); | |
297 | EXPORT_SYMBOL(default_mtd_readv); | |
298 | ||
299 | /*====================================================================*/ | |
300 | /* Power management code */ | |
301 | ||
302 | #ifdef CONFIG_PM | |
303 | ||
304 | #include <linux/pm.h> | |
305 | ||
306 | static struct pm_dev *mtd_pm_dev = NULL; | |
307 | ||
308 | static int mtd_pm_callback(struct pm_dev *dev, pm_request_t rqst, void *data) | |
309 | { | |
310 | int ret = 0, i; | |
311 | ||
312 | if (down_trylock(&mtd_table_mutex)) | |
313 | return -EAGAIN; | |
314 | if (rqst == PM_SUSPEND) { | |
315 | for (i = 0; ret == 0 && i < MAX_MTD_DEVICES; i++) { | |
316 | if (mtd_table[i] && mtd_table[i]->suspend) | |
317 | ret = mtd_table[i]->suspend(mtd_table[i]); | |
318 | } | |
319 | } else i = MAX_MTD_DEVICES-1; | |
320 | ||
321 | if (rqst == PM_RESUME || ret) { | |
322 | for ( ; i >= 0; i--) { | |
323 | if (mtd_table[i] && mtd_table[i]->resume) | |
324 | mtd_table[i]->resume(mtd_table[i]); | |
325 | } | |
326 | } | |
327 | up(&mtd_table_mutex); | |
328 | return ret; | |
329 | } | |
330 | #endif | |
331 | ||
332 | /*====================================================================*/ | |
333 | /* Support for /proc/mtd */ | |
334 | ||
335 | #ifdef CONFIG_PROC_FS | |
336 | static struct proc_dir_entry *proc_mtd; | |
337 | ||
338 | static inline int mtd_proc_info (char *buf, int i) | |
339 | { | |
340 | struct mtd_info *this = mtd_table[i]; | |
341 | ||
342 | if (!this) | |
343 | return 0; | |
344 | ||
345 | return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size, | |
346 | this->erasesize, this->name); | |
347 | } | |
348 | ||
349 | static int mtd_read_proc (char *page, char **start, off_t off, int count, | |
350 | int *eof, void *data_unused) | |
351 | { | |
352 | int len, l, i; | |
353 | off_t begin = 0; | |
354 | ||
355 | down(&mtd_table_mutex); | |
356 | ||
357 | len = sprintf(page, "dev: size erasesize name\n"); | |
358 | for (i=0; i< MAX_MTD_DEVICES; i++) { | |
359 | ||
360 | l = mtd_proc_info(page + len, i); | |
361 | len += l; | |
362 | if (len+begin > off+count) | |
363 | goto done; | |
364 | if (len+begin < off) { | |
365 | begin += len; | |
366 | len = 0; | |
367 | } | |
368 | } | |
369 | ||
370 | *eof = 1; | |
371 | ||
372 | done: | |
373 | up(&mtd_table_mutex); | |
374 | if (off >= len+begin) | |
375 | return 0; | |
376 | *start = page + (off-begin); | |
377 | return ((count < begin+len-off) ? count : begin+len-off); | |
378 | } | |
379 | ||
380 | #endif /* CONFIG_PROC_FS */ | |
381 | ||
382 | /*====================================================================*/ | |
383 | /* Init code */ | |
384 | ||
385 | static int __init init_mtd(void) | |
386 | { | |
387 | #ifdef CONFIG_PROC_FS | |
388 | if ((proc_mtd = create_proc_entry( "mtd", 0, NULL ))) | |
389 | proc_mtd->read_proc = mtd_read_proc; | |
390 | #endif | |
391 | ||
392 | #ifdef CONFIG_PM | |
393 | mtd_pm_dev = pm_register(PM_UNKNOWN_DEV, 0, mtd_pm_callback); | |
394 | #endif | |
395 | return 0; | |
396 | } | |
397 | ||
398 | static void __exit cleanup_mtd(void) | |
399 | { | |
400 | #ifdef CONFIG_PM | |
401 | if (mtd_pm_dev) { | |
402 | pm_unregister(mtd_pm_dev); | |
403 | mtd_pm_dev = NULL; | |
404 | } | |
405 | #endif | |
406 | ||
407 | #ifdef CONFIG_PROC_FS | |
408 | if (proc_mtd) | |
409 | remove_proc_entry( "mtd", NULL); | |
410 | #endif | |
411 | } | |
412 | ||
413 | module_init(init_mtd); | |
414 | module_exit(cleanup_mtd); | |
415 | ||
416 | ||
417 | MODULE_LICENSE("GPL"); | |
418 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
419 | MODULE_DESCRIPTION("Core MTD registration and access routines"); |