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1da177e4 | 1 | /* |
97894cda | 2 | * $Id: mtdcore.c,v 1.47 2005/11/07 11:14:20 gleixner Exp $ |
1da177e4 LT |
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> | |
1da177e4 | 22 | #include <linux/proc_fs.h> |
1da177e4 LT |
23 | |
24 | #include <linux/mtd/mtd.h> | |
25 | ||
97894cda | 26 | /* These are exported solely for the purpose of mtd_blkdevs.c. You |
1da177e4 | 27 | should not use them for _anything_ else */ |
48b19268 | 28 | DEFINE_MUTEX(mtd_table_mutex); |
1da177e4 LT |
29 | struct mtd_info *mtd_table[MAX_MTD_DEVICES]; |
30 | ||
31 | EXPORT_SYMBOL_GPL(mtd_table_mutex); | |
32 | EXPORT_SYMBOL_GPL(mtd_table); | |
33 | ||
34 | static LIST_HEAD(mtd_notifiers); | |
35 | ||
36 | /** | |
37 | * add_mtd_device - register an MTD device | |
38 | * @mtd: pointer to new MTD device info structure | |
39 | * | |
40 | * Add a device to the list of MTD devices present in the system, and | |
41 | * notify each currently active MTD 'user' of its arrival. Returns | |
42 | * zero on success or 1 on failure, which currently will only happen | |
43 | * if the number of present devices exceeds MAX_MTD_DEVICES (i.e. 16) | |
44 | */ | |
45 | ||
46 | int add_mtd_device(struct mtd_info *mtd) | |
47 | { | |
48 | int i; | |
49 | ||
48b19268 | 50 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
51 | |
52 | for (i=0; i < MAX_MTD_DEVICES; i++) | |
53 | if (!mtd_table[i]) { | |
54 | struct list_head *this; | |
55 | ||
56 | mtd_table[i] = mtd; | |
57 | mtd->index = i; | |
58 | mtd->usecount = 0; | |
59 | ||
60 | DEBUG(0, "mtd: Giving out device %d to %s\n",i, mtd->name); | |
61 | /* No need to get a refcount on the module containing | |
62 | the notifier, since we hold the mtd_table_mutex */ | |
63 | list_for_each(this, &mtd_notifiers) { | |
64 | struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list); | |
65 | not->add(mtd); | |
66 | } | |
97894cda | 67 | |
48b19268 | 68 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
69 | /* We _know_ we aren't being removed, because |
70 | our caller is still holding us here. So none | |
71 | of this try_ nonsense, and no bitching about it | |
72 | either. :) */ | |
73 | __module_get(THIS_MODULE); | |
74 | return 0; | |
75 | } | |
97894cda | 76 | |
48b19268 | 77 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
78 | return 1; |
79 | } | |
80 | ||
81 | /** | |
82 | * del_mtd_device - unregister an MTD device | |
83 | * @mtd: pointer to MTD device info structure | |
84 | * | |
85 | * Remove a device from the list of MTD devices present in the system, | |
86 | * and notify each currently active MTD 'user' of its departure. | |
87 | * Returns zero on success or 1 on failure, which currently will happen | |
88 | * if the requested device does not appear to be present in the list. | |
89 | */ | |
90 | ||
91 | int del_mtd_device (struct mtd_info *mtd) | |
92 | { | |
93 | int ret; | |
97894cda | 94 | |
48b19268 | 95 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
96 | |
97 | if (mtd_table[mtd->index] != mtd) { | |
98 | ret = -ENODEV; | |
99 | } else if (mtd->usecount) { | |
97894cda | 100 | printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", |
1da177e4 LT |
101 | mtd->index, mtd->name, mtd->usecount); |
102 | ret = -EBUSY; | |
103 | } else { | |
104 | struct list_head *this; | |
105 | ||
106 | /* No need to get a refcount on the module containing | |
107 | the notifier, since we hold the mtd_table_mutex */ | |
108 | list_for_each(this, &mtd_notifiers) { | |
109 | struct mtd_notifier *not = list_entry(this, struct mtd_notifier, list); | |
110 | not->remove(mtd); | |
111 | } | |
112 | ||
113 | mtd_table[mtd->index] = NULL; | |
114 | ||
115 | module_put(THIS_MODULE); | |
116 | ret = 0; | |
117 | } | |
118 | ||
48b19268 | 119 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
120 | return ret; |
121 | } | |
122 | ||
123 | /** | |
124 | * register_mtd_user - register a 'user' of MTD devices. | |
125 | * @new: pointer to notifier info structure | |
126 | * | |
127 | * Registers a pair of callbacks function to be called upon addition | |
128 | * or removal of MTD devices. Causes the 'add' callback to be immediately | |
129 | * invoked for each MTD device currently present in the system. | |
130 | */ | |
131 | ||
132 | void register_mtd_user (struct mtd_notifier *new) | |
133 | { | |
134 | int i; | |
135 | ||
48b19268 | 136 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
137 | |
138 | list_add(&new->list, &mtd_notifiers); | |
139 | ||
140 | __module_get(THIS_MODULE); | |
97894cda | 141 | |
1da177e4 LT |
142 | for (i=0; i< MAX_MTD_DEVICES; i++) |
143 | if (mtd_table[i]) | |
144 | new->add(mtd_table[i]); | |
145 | ||
48b19268 | 146 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
147 | } |
148 | ||
149 | /** | |
49450795 AB |
150 | * unregister_mtd_user - unregister a 'user' of MTD devices. |
151 | * @old: pointer to notifier info structure | |
1da177e4 LT |
152 | * |
153 | * Removes a callback function pair from the list of 'users' to be | |
154 | * notified upon addition or removal of MTD devices. Causes the | |
155 | * 'remove' callback to be immediately invoked for each MTD device | |
156 | * currently present in the system. | |
157 | */ | |
158 | ||
159 | int unregister_mtd_user (struct mtd_notifier *old) | |
160 | { | |
161 | int i; | |
162 | ||
48b19268 | 163 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
164 | |
165 | module_put(THIS_MODULE); | |
166 | ||
167 | for (i=0; i< MAX_MTD_DEVICES; i++) | |
168 | if (mtd_table[i]) | |
169 | old->remove(mtd_table[i]); | |
97894cda | 170 | |
1da177e4 | 171 | list_del(&old->list); |
48b19268 | 172 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
173 | return 0; |
174 | } | |
175 | ||
176 | ||
177 | /** | |
178 | * get_mtd_device - obtain a validated handle for an MTD device | |
179 | * @mtd: last known address of the required MTD device | |
180 | * @num: internal device number of the required MTD device | |
181 | * | |
182 | * Given a number and NULL address, return the num'th entry in the device | |
183 | * table, if any. Given an address and num == -1, search the device table | |
184 | * for a device with that address and return if it's still present. Given | |
185 | * both, return the num'th driver only if its address matches. Return NULL | |
186 | * if not. | |
187 | */ | |
97894cda | 188 | |
1da177e4 LT |
189 | struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) |
190 | { | |
191 | struct mtd_info *ret = NULL; | |
192 | int i; | |
193 | ||
48b19268 | 194 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
195 | |
196 | if (num == -1) { | |
197 | for (i=0; i< MAX_MTD_DEVICES; i++) | |
198 | if (mtd_table[i] == mtd) | |
199 | ret = mtd_table[i]; | |
200 | } else if (num < MAX_MTD_DEVICES) { | |
201 | ret = mtd_table[num]; | |
202 | if (mtd && mtd != ret) | |
203 | ret = NULL; | |
204 | } | |
205 | ||
206 | if (ret && !try_module_get(ret->owner)) | |
207 | ret = NULL; | |
208 | ||
209 | if (ret) | |
210 | ret->usecount++; | |
211 | ||
48b19268 | 212 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
213 | return ret; |
214 | } | |
215 | ||
216 | void put_mtd_device(struct mtd_info *mtd) | |
217 | { | |
218 | int c; | |
219 | ||
48b19268 | 220 | mutex_lock(&mtd_table_mutex); |
1da177e4 | 221 | c = --mtd->usecount; |
48b19268 | 222 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
223 | BUG_ON(c < 0); |
224 | ||
225 | module_put(mtd->owner); | |
226 | } | |
227 | ||
228 | /* default_mtd_writev - default mtd writev method for MTD devices that | |
229 | * dont implement their own | |
230 | */ | |
231 | ||
232 | int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, | |
233 | unsigned long count, loff_t to, size_t *retlen) | |
234 | { | |
235 | unsigned long i; | |
236 | size_t totlen = 0, thislen; | |
237 | int ret = 0; | |
238 | ||
239 | if(!mtd->write) { | |
240 | ret = -EROFS; | |
241 | } else { | |
242 | for (i=0; i<count; i++) { | |
243 | if (!vecs[i].iov_len) | |
244 | continue; | |
245 | ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base); | |
246 | totlen += thislen; | |
247 | if (ret || thislen != vecs[i].iov_len) | |
248 | break; | |
249 | to += vecs[i].iov_len; | |
250 | } | |
251 | } | |
252 | if (retlen) | |
253 | *retlen = totlen; | |
254 | return ret; | |
255 | } | |
256 | ||
1da177e4 LT |
257 | EXPORT_SYMBOL(add_mtd_device); |
258 | EXPORT_SYMBOL(del_mtd_device); | |
259 | EXPORT_SYMBOL(get_mtd_device); | |
260 | EXPORT_SYMBOL(put_mtd_device); | |
261 | EXPORT_SYMBOL(register_mtd_user); | |
262 | EXPORT_SYMBOL(unregister_mtd_user); | |
263 | EXPORT_SYMBOL(default_mtd_writev); | |
1da177e4 | 264 | |
2d2dce0e PM |
265 | #ifdef CONFIG_PROC_FS |
266 | ||
1da177e4 LT |
267 | /*====================================================================*/ |
268 | /* Support for /proc/mtd */ | |
269 | ||
1da177e4 LT |
270 | static struct proc_dir_entry *proc_mtd; |
271 | ||
272 | static inline int mtd_proc_info (char *buf, int i) | |
273 | { | |
274 | struct mtd_info *this = mtd_table[i]; | |
275 | ||
276 | if (!this) | |
277 | return 0; | |
278 | ||
279 | return sprintf(buf, "mtd%d: %8.8x %8.8x \"%s\"\n", i, this->size, | |
280 | this->erasesize, this->name); | |
281 | } | |
282 | ||
283 | static int mtd_read_proc (char *page, char **start, off_t off, int count, | |
284 | int *eof, void *data_unused) | |
285 | { | |
286 | int len, l, i; | |
287 | off_t begin = 0; | |
288 | ||
48b19268 | 289 | mutex_lock(&mtd_table_mutex); |
1da177e4 LT |
290 | |
291 | len = sprintf(page, "dev: size erasesize name\n"); | |
292 | for (i=0; i< MAX_MTD_DEVICES; i++) { | |
293 | ||
294 | l = mtd_proc_info(page + len, i); | |
295 | len += l; | |
296 | if (len+begin > off+count) | |
297 | goto done; | |
298 | if (len+begin < off) { | |
299 | begin += len; | |
300 | len = 0; | |
301 | } | |
302 | } | |
303 | ||
304 | *eof = 1; | |
305 | ||
306 | done: | |
48b19268 | 307 | mutex_unlock(&mtd_table_mutex); |
1da177e4 LT |
308 | if (off >= len+begin) |
309 | return 0; | |
310 | *start = page + (off-begin); | |
311 | return ((count < begin+len-off) ? count : begin+len-off); | |
312 | } | |
313 | ||
1da177e4 LT |
314 | /*====================================================================*/ |
315 | /* Init code */ | |
316 | ||
317 | static int __init init_mtd(void) | |
318 | { | |
1da177e4 LT |
319 | if ((proc_mtd = create_proc_entry( "mtd", 0, NULL ))) |
320 | proc_mtd->read_proc = mtd_read_proc; | |
1da177e4 LT |
321 | return 0; |
322 | } | |
323 | ||
324 | static void __exit cleanup_mtd(void) | |
325 | { | |
1da177e4 LT |
326 | if (proc_mtd) |
327 | remove_proc_entry( "mtd", NULL); | |
1da177e4 LT |
328 | } |
329 | ||
330 | module_init(init_mtd); | |
331 | module_exit(cleanup_mtd); | |
332 | ||
2d2dce0e PM |
333 | #endif /* CONFIG_PROC_FS */ |
334 | ||
1da177e4 LT |
335 | |
336 | MODULE_LICENSE("GPL"); | |
337 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); | |
338 | MODULE_DESCRIPTION("Core MTD registration and access routines"); |