1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/char_dev.c |
4 | * |
5 | * Copyright (C) 1991, 1992 Linus Torvalds |
6 | */ |
7 | |
8 | #include <linux/init.h> |
9 | #include <linux/fs.h> |
10 | #include <linux/kdev_t.h> |
11 | #include <linux/slab.h> |
12 | #include <linux/string.h> |
13 | |
14 | #include <linux/major.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/module.h> |
17 | #include <linux/seq_file.h> |
18 | |
19 | #include <linux/kobject.h> |
20 | #include <linux/kobj_map.h> |
21 | #include <linux/cdev.h> |
22 | #include <linux/mutex.h> |
23 | #include <linux/backing-dev.h> |
24 | #include <linux/tty.h> |
25 | |
26 | #include "internal.h" |
27 | |
28 | static struct kobj_map *cdev_map; |
29 | |
30 | static DEFINE_MUTEX(chrdevs_lock); |
31 | |
32 | #define CHRDEV_MAJOR_HASH_SIZE 255 |
33 | |
34 | static struct char_device_struct { |
35 | struct char_device_struct *next; |
36 | unsigned int major; |
37 | unsigned int baseminor; |
38 | int minorct; |
39 | char name[64]; |
40 | struct cdev *cdev; /* will die */ |
41 | } *chrdevs[CHRDEV_MAJOR_HASH_SIZE]; |
42 | |
43 | /* index in the above */ |
44 | static inline int major_to_index(unsigned major) |
45 | { |
46 | return major % CHRDEV_MAJOR_HASH_SIZE; |
47 | } |
48 | |
49 | #ifdef CONFIG_PROC_FS |
50 | |
51 | void chrdev_show(struct seq_file *f, off_t offset) |
52 | { |
53 | struct char_device_struct *cd; |
54 | |
55 | mutex_lock(&chrdevs_lock); |
56 | for (cd = chrdevs[major_to_index(offset)]; cd; cd = cd->next) { |
57 | if (cd->major == offset) |
58 | seq_printf(f, "%3d %s\n" , cd->major, cd->name); |
59 | } |
60 | mutex_unlock(&chrdevs_lock); |
61 | } |
62 | |
63 | #endif /* CONFIG_PROC_FS */ |
64 | |
65 | static int find_dynamic_major(void) |
66 | { |
67 | int i; |
68 | struct char_device_struct *cd; |
69 | |
70 | for (i = ARRAY_SIZE(chrdevs)-1; i >= CHRDEV_MAJOR_DYN_END; i--) { |
71 | if (chrdevs[i] == NULL) |
72 | return i; |
73 | } |
74 | |
75 | for (i = CHRDEV_MAJOR_DYN_EXT_START; |
76 | i >= CHRDEV_MAJOR_DYN_EXT_END; i--) { |
77 | for (cd = chrdevs[major_to_index(i)]; cd; cd = cd->next) |
78 | if (cd->major == i) |
79 | break; |
80 | |
81 | if (cd == NULL) |
82 | return i; |
83 | } |
84 | |
85 | return -EBUSY; |
86 | } |
87 | |
88 | /* |
89 | * Register a single major with a specified minor range. |
90 | * |
91 | * If major == 0 this functions will dynamically allocate a major and return |
92 | * its number. |
93 | * |
94 | * If major > 0 this function will attempt to reserve the passed range of |
95 | * minors and will return zero on success. |
96 | * |
97 | * Returns a -ve errno on failure. |
98 | */ |
99 | static struct char_device_struct * |
100 | __register_chrdev_region(unsigned int major, unsigned int baseminor, |
101 | int minorct, const char *name) |
102 | { |
103 | struct char_device_struct *cd, **cp; |
104 | int ret = 0; |
105 | int i; |
106 | |
107 | cd = kzalloc(sizeof(struct char_device_struct), GFP_KERNEL); |
108 | if (cd == NULL) |
109 | return ERR_PTR(-ENOMEM); |
110 | |
111 | mutex_lock(&chrdevs_lock); |
112 | |
113 | if (major == 0) { |
114 | ret = find_dynamic_major(); |
115 | if (ret < 0) { |
116 | pr_err("CHRDEV \"%s\" dynamic allocation region is full\n" , |
117 | name); |
118 | goto out; |
119 | } |
120 | major = ret; |
121 | } |
122 | |
123 | if (major >= CHRDEV_MAJOR_MAX) { |
124 | pr_err("CHRDEV \"%s\" major requested (%u) is greater than the maximum (%u)\n" , |
125 | name, major, CHRDEV_MAJOR_MAX-1); |
126 | ret = -EINVAL; |
127 | goto out; |
128 | } |
129 | |
130 | cd->major = major; |
131 | cd->baseminor = baseminor; |
132 | cd->minorct = minorct; |
133 | strlcpy(cd->name, name, sizeof(cd->name)); |
134 | |
135 | i = major_to_index(major); |
136 | |
137 | for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next) |
138 | if ((*cp)->major > major || |
139 | ((*cp)->major == major && |
140 | (((*cp)->baseminor >= baseminor) || |
141 | ((*cp)->baseminor + (*cp)->minorct > baseminor)))) |
142 | break; |
143 | |
144 | /* Check for overlapping minor ranges. */ |
145 | if (*cp && (*cp)->major == major) { |
146 | int old_min = (*cp)->baseminor; |
147 | int old_max = (*cp)->baseminor + (*cp)->minorct - 1; |
148 | int new_min = baseminor; |
149 | int new_max = baseminor + minorct - 1; |
150 | |
151 | /* New driver overlaps from the left. */ |
152 | if (new_max >= old_min && new_max <= old_max) { |
153 | ret = -EBUSY; |
154 | goto out; |
155 | } |
156 | |
157 | /* New driver overlaps from the right. */ |
158 | if (new_min <= old_max && new_min >= old_min) { |
159 | ret = -EBUSY; |
160 | goto out; |
161 | } |
162 | } |
163 | |
164 | cd->next = *cp; |
165 | *cp = cd; |
166 | mutex_unlock(&chrdevs_lock); |
167 | return cd; |
168 | out: |
169 | mutex_unlock(&chrdevs_lock); |
170 | kfree(cd); |
171 | return ERR_PTR(ret); |
172 | } |
173 | |
174 | static struct char_device_struct * |
175 | __unregister_chrdev_region(unsigned major, unsigned baseminor, int minorct) |
176 | { |
177 | struct char_device_struct *cd = NULL, **cp; |
178 | int i = major_to_index(major); |
179 | |
180 | mutex_lock(&chrdevs_lock); |
181 | for (cp = &chrdevs[i]; *cp; cp = &(*cp)->next) |
182 | if ((*cp)->major == major && |
183 | (*cp)->baseminor == baseminor && |
184 | (*cp)->minorct == minorct) |
185 | break; |
186 | if (*cp) { |
187 | cd = *cp; |
188 | *cp = cd->next; |
189 | } |
190 | mutex_unlock(&chrdevs_lock); |
191 | return cd; |
192 | } |
193 | |
194 | /** |
195 | * register_chrdev_region() - register a range of device numbers |
196 | * @from: the first in the desired range of device numbers; must include |
197 | * the major number. |
198 | * @count: the number of consecutive device numbers required |
199 | * @name: the name of the device or driver. |
200 | * |
201 | * Return value is zero on success, a negative error code on failure. |
202 | */ |
203 | int register_chrdev_region(dev_t from, unsigned count, const char *name) |
204 | { |
205 | struct char_device_struct *cd; |
206 | dev_t to = from + count; |
207 | dev_t n, next; |
208 | |
209 | for (n = from; n < to; n = next) { |
210 | next = MKDEV(MAJOR(n)+1, 0); |
211 | if (next > to) |
212 | next = to; |
213 | cd = __register_chrdev_region(MAJOR(n), MINOR(n), |
214 | next - n, name); |
215 | if (IS_ERR(cd)) |
216 | goto fail; |
217 | } |
218 | return 0; |
219 | fail: |
220 | to = n; |
221 | for (n = from; n < to; n = next) { |
222 | next = MKDEV(MAJOR(n)+1, 0); |
223 | kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n)); |
224 | } |
225 | return PTR_ERR(cd); |
226 | } |
227 | |
228 | /** |
229 | * alloc_chrdev_region() - register a range of char device numbers |
230 | * @dev: output parameter for first assigned number |
231 | * @baseminor: first of the requested range of minor numbers |
232 | * @count: the number of minor numbers required |
233 | * @name: the name of the associated device or driver |
234 | * |
235 | * Allocates a range of char device numbers. The major number will be |
236 | * chosen dynamically, and returned (along with the first minor number) |
237 | * in @dev. Returns zero or a negative error code. |
238 | */ |
239 | int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count, |
240 | const char *name) |
241 | { |
242 | struct char_device_struct *cd; |
243 | cd = __register_chrdev_region(0, baseminor, count, name); |
244 | if (IS_ERR(cd)) |
245 | return PTR_ERR(cd); |
246 | *dev = MKDEV(cd->major, cd->baseminor); |
247 | return 0; |
248 | } |
249 | |
250 | /** |
251 | * __register_chrdev() - create and register a cdev occupying a range of minors |
252 | * @major: major device number or 0 for dynamic allocation |
253 | * @baseminor: first of the requested range of minor numbers |
254 | * @count: the number of minor numbers required |
255 | * @name: name of this range of devices |
256 | * @fops: file operations associated with this devices |
257 | * |
258 | * If @major == 0 this functions will dynamically allocate a major and return |
259 | * its number. |
260 | * |
261 | * If @major > 0 this function will attempt to reserve a device with the given |
262 | * major number and will return zero on success. |
263 | * |
264 | * Returns a -ve errno on failure. |
265 | * |
266 | * The name of this device has nothing to do with the name of the device in |
267 | * /dev. It only helps to keep track of the different owners of devices. If |
268 | * your module name has only one type of devices it's ok to use e.g. the name |
269 | * of the module here. |
270 | */ |
271 | int __register_chrdev(unsigned int major, unsigned int baseminor, |
272 | unsigned int count, const char *name, |
273 | const struct file_operations *fops) |
274 | { |
275 | struct char_device_struct *cd; |
276 | struct cdev *cdev; |
277 | int err = -ENOMEM; |
278 | |
279 | cd = __register_chrdev_region(major, baseminor, count, name); |
280 | if (IS_ERR(cd)) |
281 | return PTR_ERR(cd); |
282 | |
283 | cdev = cdev_alloc(); |
284 | if (!cdev) |
285 | goto out2; |
286 | |
287 | cdev->owner = fops->owner; |
288 | cdev->ops = fops; |
289 | kobject_set_name(&cdev->kobj, "%s" , name); |
290 | |
291 | err = cdev_add(cdev, MKDEV(cd->major, baseminor), count); |
292 | if (err) |
293 | goto out; |
294 | |
295 | cd->cdev = cdev; |
296 | |
297 | return major ? 0 : cd->major; |
298 | out: |
299 | kobject_put(&cdev->kobj); |
300 | out2: |
301 | kfree(__unregister_chrdev_region(cd->major, baseminor, count)); |
302 | return err; |
303 | } |
304 | |
305 | /** |
306 | * unregister_chrdev_region() - unregister a range of device numbers |
307 | * @from: the first in the range of numbers to unregister |
308 | * @count: the number of device numbers to unregister |
309 | * |
310 | * This function will unregister a range of @count device numbers, |
311 | * starting with @from. The caller should normally be the one who |
312 | * allocated those numbers in the first place... |
313 | */ |
314 | void unregister_chrdev_region(dev_t from, unsigned count) |
315 | { |
316 | dev_t to = from + count; |
317 | dev_t n, next; |
318 | |
319 | for (n = from; n < to; n = next) { |
320 | next = MKDEV(MAJOR(n)+1, 0); |
321 | if (next > to) |
322 | next = to; |
323 | kfree(__unregister_chrdev_region(MAJOR(n), MINOR(n), next - n)); |
324 | } |
325 | } |
326 | |
327 | /** |
328 | * __unregister_chrdev - unregister and destroy a cdev |
329 | * @major: major device number |
330 | * @baseminor: first of the range of minor numbers |
331 | * @count: the number of minor numbers this cdev is occupying |
332 | * @name: name of this range of devices |
333 | * |
334 | * Unregister and destroy the cdev occupying the region described by |
335 | * @major, @baseminor and @count. This function undoes what |
336 | * __register_chrdev() did. |
337 | */ |
338 | void __unregister_chrdev(unsigned int major, unsigned int baseminor, |
339 | unsigned int count, const char *name) |
340 | { |
341 | struct char_device_struct *cd; |
342 | |
343 | cd = __unregister_chrdev_region(major, baseminor, count); |
344 | if (cd && cd->cdev) |
345 | cdev_del(cd->cdev); |
346 | kfree(cd); |
347 | } |
348 | |
349 | static DEFINE_SPINLOCK(cdev_lock); |
350 | |
351 | static struct kobject *cdev_get(struct cdev *p) |
352 | { |
353 | struct module *owner = p->owner; |
354 | struct kobject *kobj; |
355 | |
356 | if (owner && !try_module_get(owner)) |
357 | return NULL; |
358 | kobj = kobject_get(&p->kobj); |
359 | if (!kobj) |
360 | module_put(owner); |
361 | return kobj; |
362 | } |
363 | |
364 | void cdev_put(struct cdev *p) |
365 | { |
366 | if (p) { |
367 | struct module *owner = p->owner; |
368 | kobject_put(&p->kobj); |
369 | module_put(owner); |
370 | } |
371 | } |
372 | |
373 | /* |
374 | * Called every time a character special file is opened |
375 | */ |
376 | static int chrdev_open(struct inode *inode, struct file *filp) |
377 | { |
378 | const struct file_operations *fops; |
379 | struct cdev *p; |
380 | struct cdev *new = NULL; |
381 | int ret = 0; |
382 | |
383 | spin_lock(&cdev_lock); |
384 | p = inode->i_cdev; |
385 | if (!p) { |
386 | struct kobject *kobj; |
387 | int idx; |
388 | spin_unlock(&cdev_lock); |
389 | kobj = kobj_lookup(cdev_map, inode->i_rdev, &idx); |
390 | if (!kobj) |
391 | return -ENXIO; |
392 | new = container_of(kobj, struct cdev, kobj); |
393 | spin_lock(&cdev_lock); |
394 | /* Check i_cdev again in case somebody beat us to it while |
395 | we dropped the lock. */ |
396 | p = inode->i_cdev; |
397 | if (!p) { |
398 | inode->i_cdev = p = new; |
399 | list_add(&inode->i_devices, &p->list); |
400 | new = NULL; |
401 | } else if (!cdev_get(p)) |
402 | ret = -ENXIO; |
403 | } else if (!cdev_get(p)) |
404 | ret = -ENXIO; |
405 | spin_unlock(&cdev_lock); |
406 | cdev_put(new); |
407 | if (ret) |
408 | return ret; |
409 | |
410 | ret = -ENXIO; |
411 | fops = fops_get(p->ops); |
412 | if (!fops) |
413 | goto out_cdev_put; |
414 | |
415 | replace_fops(filp, fops); |
416 | if (filp->f_op->open) { |
417 | ret = filp->f_op->open(inode, filp); |
418 | if (ret) |
419 | goto out_cdev_put; |
420 | } |
421 | |
422 | return 0; |
423 | |
424 | out_cdev_put: |
425 | cdev_put(p); |
426 | return ret; |
427 | } |
428 | |
429 | void cd_forget(struct inode *inode) |
430 | { |
431 | spin_lock(&cdev_lock); |
432 | list_del_init(&inode->i_devices); |
433 | inode->i_cdev = NULL; |
434 | inode->i_mapping = &inode->i_data; |
435 | spin_unlock(&cdev_lock); |
436 | } |
437 | |
438 | static void cdev_purge(struct cdev *cdev) |
439 | { |
440 | spin_lock(&cdev_lock); |
441 | while (!list_empty(&cdev->list)) { |
442 | struct inode *inode; |
443 | inode = container_of(cdev->list.next, struct inode, i_devices); |
444 | list_del_init(&inode->i_devices); |
445 | inode->i_cdev = NULL; |
446 | } |
447 | spin_unlock(&cdev_lock); |
448 | } |
449 | |
450 | /* |
451 | * Dummy default file-operations: the only thing this does |
452 | * is contain the open that then fills in the correct operations |
453 | * depending on the special file... |
454 | */ |
455 | const struct file_operations def_chr_fops = { |
456 | .open = chrdev_open, |
457 | .llseek = noop_llseek, |
458 | }; |
459 | |
460 | static struct kobject *exact_match(dev_t dev, int *part, void *data) |
461 | { |
462 | struct cdev *p = data; |
463 | return &p->kobj; |
464 | } |
465 | |
466 | static int exact_lock(dev_t dev, void *data) |
467 | { |
468 | struct cdev *p = data; |
469 | return cdev_get(p) ? 0 : -1; |
470 | } |
471 | |
472 | /** |
473 | * cdev_add() - add a char device to the system |
474 | * @p: the cdev structure for the device |
475 | * @dev: the first device number for which this device is responsible |
476 | * @count: the number of consecutive minor numbers corresponding to this |
477 | * device |
478 | * |
479 | * cdev_add() adds the device represented by @p to the system, making it |
480 | * live immediately. A negative error code is returned on failure. |
481 | */ |
482 | int cdev_add(struct cdev *p, dev_t dev, unsigned count) |
483 | { |
484 | int error; |
485 | |
486 | p->dev = dev; |
487 | p->count = count; |
488 | |
489 | error = kobj_map(cdev_map, dev, count, NULL, |
490 | exact_match, exact_lock, p); |
491 | if (error) |
492 | return error; |
493 | |
494 | kobject_get(p->kobj.parent); |
495 | |
496 | return 0; |
497 | } |
498 | |
499 | /** |
500 | * cdev_set_parent() - set the parent kobject for a char device |
501 | * @p: the cdev structure |
502 | * @kobj: the kobject to take a reference to |
503 | * |
504 | * cdev_set_parent() sets a parent kobject which will be referenced |
505 | * appropriately so the parent is not freed before the cdev. This |
506 | * should be called before cdev_add. |
507 | */ |
508 | void cdev_set_parent(struct cdev *p, struct kobject *kobj) |
509 | { |
510 | WARN_ON(!kobj->state_initialized); |
511 | p->kobj.parent = kobj; |
512 | } |
513 | |
514 | /** |
515 | * cdev_device_add() - add a char device and it's corresponding |
516 | * struct device, linkink |
517 | * @dev: the device structure |
518 | * @cdev: the cdev structure |
519 | * |
520 | * cdev_device_add() adds the char device represented by @cdev to the system, |
521 | * just as cdev_add does. It then adds @dev to the system using device_add |
522 | * The dev_t for the char device will be taken from the struct device which |
523 | * needs to be initialized first. This helper function correctly takes a |
524 | * reference to the parent device so the parent will not get released until |
525 | * all references to the cdev are released. |
526 | * |
527 | * This helper uses dev->devt for the device number. If it is not set |
528 | * it will not add the cdev and it will be equivalent to device_add. |
529 | * |
530 | * This function should be used whenever the struct cdev and the |
531 | * struct device are members of the same structure whose lifetime is |
532 | * managed by the struct device. |
533 | * |
534 | * NOTE: Callers must assume that userspace was able to open the cdev and |
535 | * can call cdev fops callbacks at any time, even if this function fails. |
536 | */ |
537 | int cdev_device_add(struct cdev *cdev, struct device *dev) |
538 | { |
539 | int rc = 0; |
540 | |
541 | if (dev->devt) { |
542 | cdev_set_parent(cdev, &dev->kobj); |
543 | |
544 | rc = cdev_add(cdev, dev->devt, 1); |
545 | if (rc) |
546 | return rc; |
547 | } |
548 | |
549 | rc = device_add(dev); |
550 | if (rc) |
551 | cdev_del(cdev); |
552 | |
553 | return rc; |
554 | } |
555 | |
556 | /** |
557 | * cdev_device_del() - inverse of cdev_device_add |
558 | * @dev: the device structure |
559 | * @cdev: the cdev structure |
560 | * |
561 | * cdev_device_del() is a helper function to call cdev_del and device_del. |
562 | * It should be used whenever cdev_device_add is used. |
563 | * |
564 | * If dev->devt is not set it will not remove the cdev and will be equivalent |
565 | * to device_del. |
566 | * |
567 | * NOTE: This guarantees that associated sysfs callbacks are not running |
568 | * or runnable, however any cdevs already open will remain and their fops |
569 | * will still be callable even after this function returns. |
570 | */ |
571 | void cdev_device_del(struct cdev *cdev, struct device *dev) |
572 | { |
573 | device_del(dev); |
574 | if (dev->devt) |
575 | cdev_del(cdev); |
576 | } |
577 | |
578 | static void cdev_unmap(dev_t dev, unsigned count) |
579 | { |
580 | kobj_unmap(cdev_map, dev, count); |
581 | } |
582 | |
583 | /** |
584 | * cdev_del() - remove a cdev from the system |
585 | * @p: the cdev structure to be removed |
586 | * |
587 | * cdev_del() removes @p from the system, possibly freeing the structure |
588 | * itself. |
589 | * |
590 | * NOTE: This guarantees that cdev device will no longer be able to be |
591 | * opened, however any cdevs already open will remain and their fops will |
592 | * still be callable even after cdev_del returns. |
593 | */ |
594 | void cdev_del(struct cdev *p) |
595 | { |
596 | cdev_unmap(p->dev, p->count); |
597 | kobject_put(&p->kobj); |
598 | } |
599 | |
600 | |
601 | static void cdev_default_release(struct kobject *kobj) |
602 | { |
603 | struct cdev *p = container_of(kobj, struct cdev, kobj); |
604 | struct kobject *parent = kobj->parent; |
605 | |
606 | cdev_purge(p); |
607 | kobject_put(parent); |
608 | } |
609 | |
610 | static void cdev_dynamic_release(struct kobject *kobj) |
611 | { |
612 | struct cdev *p = container_of(kobj, struct cdev, kobj); |
613 | struct kobject *parent = kobj->parent; |
614 | |
615 | cdev_purge(p); |
616 | kfree(p); |
617 | kobject_put(parent); |
618 | } |
619 | |
620 | static struct kobj_type ktype_cdev_default = { |
621 | .release = cdev_default_release, |
622 | }; |
623 | |
624 | static struct kobj_type ktype_cdev_dynamic = { |
625 | .release = cdev_dynamic_release, |
626 | }; |
627 | |
628 | /** |
629 | * cdev_alloc() - allocate a cdev structure |
630 | * |
631 | * Allocates and returns a cdev structure, or NULL on failure. |
632 | */ |
633 | struct cdev *cdev_alloc(void) |
634 | { |
635 | struct cdev *p = kzalloc(sizeof(struct cdev), GFP_KERNEL); |
636 | if (p) { |
637 | INIT_LIST_HEAD(&p->list); |
638 | kobject_init(&p->kobj, &ktype_cdev_dynamic); |
639 | } |
640 | return p; |
641 | } |
642 | |
643 | /** |
644 | * cdev_init() - initialize a cdev structure |
645 | * @cdev: the structure to initialize |
646 | * @fops: the file_operations for this device |
647 | * |
648 | * Initializes @cdev, remembering @fops, making it ready to add to the |
649 | * system with cdev_add(). |
650 | */ |
651 | void cdev_init(struct cdev *cdev, const struct file_operations *fops) |
652 | { |
653 | memset(cdev, 0, sizeof *cdev); |
654 | INIT_LIST_HEAD(&cdev->list); |
655 | kobject_init(&cdev->kobj, &ktype_cdev_default); |
656 | cdev->ops = fops; |
657 | } |
658 | |
659 | static struct kobject *base_probe(dev_t dev, int *part, void *data) |
660 | { |
661 | if (request_module("char-major-%d-%d" , MAJOR(dev), MINOR(dev)) > 0) |
662 | /* Make old-style 2.4 aliases work */ |
663 | request_module("char-major-%d" , MAJOR(dev)); |
664 | return NULL; |
665 | } |
666 | |
667 | void __init chrdev_init(void) |
668 | { |
669 | cdev_map = kobj_map_init(base_probe, &chrdevs_lock); |
670 | } |
671 | |
672 | |
673 | /* Let modules do char dev stuff */ |
674 | EXPORT_SYMBOL(register_chrdev_region); |
675 | EXPORT_SYMBOL(unregister_chrdev_region); |
676 | EXPORT_SYMBOL(alloc_chrdev_region); |
677 | EXPORT_SYMBOL(cdev_init); |
678 | EXPORT_SYMBOL(cdev_alloc); |
679 | EXPORT_SYMBOL(cdev_del); |
680 | EXPORT_SYMBOL(cdev_add); |
681 | EXPORT_SYMBOL(cdev_set_parent); |
682 | EXPORT_SYMBOL(cdev_device_add); |
683 | EXPORT_SYMBOL(cdev_device_del); |
684 | EXPORT_SYMBOL(__register_chrdev); |
685 | EXPORT_SYMBOL(__unregister_chrdev); |
686 | |