Commit | Line | Data |
---|---|---|
844dd05f MB |
1 | /* |
2 | Added support for the AMD Geode LX RNG | |
3 | (c) Copyright 2004-2005 Advanced Micro Devices, Inc. | |
4 | ||
5 | derived from | |
6 | ||
7 | Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG) | |
8 | (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com> | |
9 | ||
10 | derived from | |
11 | ||
12 | Hardware driver for the AMD 768 Random Number Generator (RNG) | |
13 | (c) Copyright 2001 Red Hat Inc <alan@redhat.com> | |
14 | ||
15 | derived from | |
16 | ||
17 | Hardware driver for Intel i810 Random Number Generator (RNG) | |
18 | Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com> | |
19 | Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com> | |
20 | ||
21 | Added generic RNG API | |
eb032b98 | 22 | Copyright 2006 Michael Buesch <m@bues.ch> |
844dd05f MB |
23 | Copyright 2005 (c) MontaVista Software, Inc. |
24 | ||
25 | Please read Documentation/hw_random.txt for details on use. | |
26 | ||
27 | ---------------------------------------------------------- | |
28 | This software may be used and distributed according to the terms | |
29 | of the GNU General Public License, incorporated herein by reference. | |
30 | ||
31 | */ | |
32 | ||
33 | ||
34 | #include <linux/device.h> | |
35 | #include <linux/hw_random.h> | |
36 | #include <linux/module.h> | |
37 | #include <linux/kernel.h> | |
38 | #include <linux/fs.h> | |
914e2637 | 39 | #include <linux/sched.h> |
844dd05f | 40 | #include <linux/miscdevice.h> |
be4000bc | 41 | #include <linux/kthread.h> |
844dd05f | 42 | #include <linux/delay.h> |
f7f154f1 | 43 | #include <linux/slab.h> |
d9e79726 | 44 | #include <linux/random.h> |
3a2c0ba5 | 45 | #include <linux/err.h> |
844dd05f MB |
46 | #include <asm/uaccess.h> |
47 | ||
48 | ||
49 | #define RNG_MODULE_NAME "hw_random" | |
50 | #define PFX RNG_MODULE_NAME ": " | |
51 | #define RNG_MISCDEV_MINOR 183 /* official */ | |
52 | ||
53 | ||
54 | static struct hwrng *current_rng; | |
be4000bc | 55 | static struct task_struct *hwrng_fill; |
844dd05f | 56 | static LIST_HEAD(rng_list); |
9372b35e | 57 | /* Protects rng_list and current_rng */ |
844dd05f | 58 | static DEFINE_MUTEX(rng_mutex); |
9372b35e RR |
59 | /* Protects rng read functions, data_avail, rng_buffer and rng_fillbuf */ |
60 | static DEFINE_MUTEX(reading_mutex); | |
9996508b | 61 | static int data_avail; |
be4000bc | 62 | static u8 *rng_buffer, *rng_fillbuf; |
0f734e6e TD |
63 | static unsigned short current_quality; |
64 | static unsigned short default_quality; /* = 0; default to "off" */ | |
be4000bc TD |
65 | |
66 | module_param(current_quality, ushort, 0644); | |
67 | MODULE_PARM_DESC(current_quality, | |
68 | "current hwrng entropy estimation per mill"); | |
0f734e6e TD |
69 | module_param(default_quality, ushort, 0644); |
70 | MODULE_PARM_DESC(default_quality, | |
71 | "default entropy content of hwrng per mill"); | |
be4000bc | 72 | |
ff77c150 | 73 | static void drop_current_rng(void); |
90ac41bd | 74 | static int hwrng_init(struct hwrng *rng); |
be4000bc | 75 | static void start_khwrngd(void); |
f7f154f1 | 76 | |
d3cc7996 AS |
77 | static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, |
78 | int wait); | |
79 | ||
f7f154f1 RR |
80 | static size_t rng_buffer_size(void) |
81 | { | |
82 | return SMP_CACHE_BYTES < 32 ? 32 : SMP_CACHE_BYTES; | |
83 | } | |
844dd05f | 84 | |
d3cc7996 AS |
85 | static void add_early_randomness(struct hwrng *rng) |
86 | { | |
87 | unsigned char bytes[16]; | |
88 | int bytes_read; | |
89 | ||
9372b35e | 90 | mutex_lock(&reading_mutex); |
d3cc7996 | 91 | bytes_read = rng_get_data(rng, bytes, sizeof(bytes), 1); |
9372b35e | 92 | mutex_unlock(&reading_mutex); |
d3cc7996 AS |
93 | if (bytes_read > 0) |
94 | add_device_randomness(bytes, bytes_read); | |
95 | } | |
96 | ||
3a2c0ba5 RR |
97 | static inline void cleanup_rng(struct kref *kref) |
98 | { | |
99 | struct hwrng *rng = container_of(kref, struct hwrng, ref); | |
100 | ||
101 | if (rng->cleanup) | |
102 | rng->cleanup(rng); | |
a027f30d | 103 | |
77584ee5 | 104 | complete(&rng->cleanup_done); |
3a2c0ba5 RR |
105 | } |
106 | ||
90ac41bd | 107 | static int set_current_rng(struct hwrng *rng) |
3a2c0ba5 | 108 | { |
90ac41bd HX |
109 | int err; |
110 | ||
3a2c0ba5 | 111 | BUG_ON(!mutex_is_locked(&rng_mutex)); |
90ac41bd HX |
112 | |
113 | err = hwrng_init(rng); | |
114 | if (err) | |
115 | return err; | |
116 | ||
ff77c150 | 117 | drop_current_rng(); |
3a2c0ba5 | 118 | current_rng = rng; |
90ac41bd HX |
119 | |
120 | return 0; | |
3a2c0ba5 RR |
121 | } |
122 | ||
123 | static void drop_current_rng(void) | |
124 | { | |
125 | BUG_ON(!mutex_is_locked(&rng_mutex)); | |
126 | if (!current_rng) | |
127 | return; | |
128 | ||
129 | /* decrease last reference for triggering the cleanup */ | |
130 | kref_put(¤t_rng->ref, cleanup_rng); | |
131 | current_rng = NULL; | |
132 | } | |
133 | ||
134 | /* Returns ERR_PTR(), NULL or refcounted hwrng */ | |
135 | static struct hwrng *get_current_rng(void) | |
136 | { | |
137 | struct hwrng *rng; | |
138 | ||
139 | if (mutex_lock_interruptible(&rng_mutex)) | |
140 | return ERR_PTR(-ERESTARTSYS); | |
141 | ||
142 | rng = current_rng; | |
143 | if (rng) | |
144 | kref_get(&rng->ref); | |
145 | ||
146 | mutex_unlock(&rng_mutex); | |
147 | return rng; | |
148 | } | |
149 | ||
150 | static void put_rng(struct hwrng *rng) | |
151 | { | |
152 | /* | |
153 | * Hold rng_mutex here so we serialize in case they set_current_rng | |
154 | * on rng again immediately. | |
155 | */ | |
156 | mutex_lock(&rng_mutex); | |
157 | if (rng) | |
158 | kref_put(&rng->ref, cleanup_rng); | |
159 | mutex_unlock(&rng_mutex); | |
160 | } | |
161 | ||
90ac41bd | 162 | static int hwrng_init(struct hwrng *rng) |
844dd05f | 163 | { |
15b66cd5 HX |
164 | if (kref_get_unless_zero(&rng->ref)) |
165 | goto skip_init; | |
166 | ||
d3cc7996 AS |
167 | if (rng->init) { |
168 | int ret; | |
169 | ||
170 | ret = rng->init(rng); | |
171 | if (ret) | |
172 | return ret; | |
173 | } | |
15b66cd5 HX |
174 | |
175 | kref_init(&rng->ref); | |
176 | reinit_completion(&rng->cleanup_done); | |
177 | ||
178 | skip_init: | |
d3cc7996 | 179 | add_early_randomness(rng); |
be4000bc | 180 | |
0f734e6e | 181 | current_quality = rng->quality ? : default_quality; |
506bf0c0 KP |
182 | if (current_quality > 1024) |
183 | current_quality = 1024; | |
0f734e6e TD |
184 | |
185 | if (current_quality == 0 && hwrng_fill) | |
186 | kthread_stop(hwrng_fill); | |
be4000bc TD |
187 | if (current_quality > 0 && !hwrng_fill) |
188 | start_khwrngd(); | |
189 | ||
d3cc7996 | 190 | return 0; |
844dd05f MB |
191 | } |
192 | ||
844dd05f MB |
193 | static int rng_dev_open(struct inode *inode, struct file *filp) |
194 | { | |
195 | /* enforce read-only access to this chrdev */ | |
196 | if ((filp->f_mode & FMODE_READ) == 0) | |
197 | return -EINVAL; | |
198 | if (filp->f_mode & FMODE_WRITE) | |
199 | return -EINVAL; | |
200 | return 0; | |
201 | } | |
202 | ||
9996508b IM |
203 | static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, |
204 | int wait) { | |
205 | int present; | |
206 | ||
9372b35e | 207 | BUG_ON(!mutex_is_locked(&reading_mutex)); |
9996508b IM |
208 | if (rng->read) |
209 | return rng->read(rng, (void *)buffer, size, wait); | |
210 | ||
211 | if (rng->data_present) | |
212 | present = rng->data_present(rng, wait); | |
213 | else | |
214 | present = 1; | |
215 | ||
216 | if (present) | |
217 | return rng->data_read(rng, (u32 *)buffer); | |
218 | ||
219 | return 0; | |
220 | } | |
221 | ||
844dd05f MB |
222 | static ssize_t rng_dev_read(struct file *filp, char __user *buf, |
223 | size_t size, loff_t *offp) | |
224 | { | |
844dd05f | 225 | ssize_t ret = 0; |
984e976f | 226 | int err = 0; |
9996508b | 227 | int bytes_read, len; |
3a2c0ba5 | 228 | struct hwrng *rng; |
844dd05f MB |
229 | |
230 | while (size) { | |
3a2c0ba5 RR |
231 | rng = get_current_rng(); |
232 | if (IS_ERR(rng)) { | |
233 | err = PTR_ERR(rng); | |
844dd05f | 234 | goto out; |
9996508b | 235 | } |
3a2c0ba5 | 236 | if (!rng) { |
844dd05f | 237 | err = -ENODEV; |
3a2c0ba5 | 238 | goto out; |
844dd05f | 239 | } |
984e976f | 240 | |
1ab87298 JS |
241 | if (mutex_lock_interruptible(&reading_mutex)) { |
242 | err = -ERESTARTSYS; | |
243 | goto out_put; | |
244 | } | |
9996508b | 245 | if (!data_avail) { |
3a2c0ba5 | 246 | bytes_read = rng_get_data(rng, rng_buffer, |
f7f154f1 | 247 | rng_buffer_size(), |
9996508b IM |
248 | !(filp->f_flags & O_NONBLOCK)); |
249 | if (bytes_read < 0) { | |
250 | err = bytes_read; | |
9372b35e | 251 | goto out_unlock_reading; |
9996508b IM |
252 | } |
253 | data_avail = bytes_read; | |
893f1128 | 254 | } |
844dd05f | 255 | |
9996508b IM |
256 | if (!data_avail) { |
257 | if (filp->f_flags & O_NONBLOCK) { | |
258 | err = -EAGAIN; | |
9372b35e | 259 | goto out_unlock_reading; |
9996508b IM |
260 | } |
261 | } else { | |
262 | len = data_avail; | |
263 | if (len > size) | |
264 | len = size; | |
265 | ||
266 | data_avail -= len; | |
267 | ||
268 | if (copy_to_user(buf + ret, rng_buffer + data_avail, | |
269 | len)) { | |
270 | err = -EFAULT; | |
9372b35e | 271 | goto out_unlock_reading; |
9996508b IM |
272 | } |
273 | ||
274 | size -= len; | |
275 | ret += len; | |
844dd05f MB |
276 | } |
277 | ||
9372b35e | 278 | mutex_unlock(&reading_mutex); |
3a2c0ba5 | 279 | put_rng(rng); |
9996508b | 280 | |
844dd05f MB |
281 | if (need_resched()) |
282 | schedule_timeout_interruptible(1); | |
9996508b IM |
283 | |
284 | if (signal_pending(current)) { | |
285 | err = -ERESTARTSYS; | |
844dd05f | 286 | goto out; |
9996508b | 287 | } |
844dd05f MB |
288 | } |
289 | out: | |
290 | return ret ? : err; | |
3a2c0ba5 | 291 | |
9372b35e RR |
292 | out_unlock_reading: |
293 | mutex_unlock(&reading_mutex); | |
1ab87298 | 294 | out_put: |
3a2c0ba5 RR |
295 | put_rng(rng); |
296 | goto out; | |
844dd05f MB |
297 | } |
298 | ||
299 | ||
62322d25 | 300 | static const struct file_operations rng_chrdev_ops = { |
844dd05f MB |
301 | .owner = THIS_MODULE, |
302 | .open = rng_dev_open, | |
303 | .read = rng_dev_read, | |
6038f373 | 304 | .llseek = noop_llseek, |
844dd05f MB |
305 | }; |
306 | ||
0daa7a0a TI |
307 | static const struct attribute_group *rng_dev_groups[]; |
308 | ||
844dd05f MB |
309 | static struct miscdevice rng_miscdev = { |
310 | .minor = RNG_MISCDEV_MINOR, | |
311 | .name = RNG_MODULE_NAME, | |
e454cea2 | 312 | .nodename = "hwrng", |
844dd05f | 313 | .fops = &rng_chrdev_ops, |
0daa7a0a | 314 | .groups = rng_dev_groups, |
844dd05f MB |
315 | }; |
316 | ||
317 | ||
94fbcded GKH |
318 | static ssize_t hwrng_attr_current_store(struct device *dev, |
319 | struct device_attribute *attr, | |
844dd05f MB |
320 | const char *buf, size_t len) |
321 | { | |
322 | int err; | |
323 | struct hwrng *rng; | |
324 | ||
325 | err = mutex_lock_interruptible(&rng_mutex); | |
326 | if (err) | |
327 | return -ERESTARTSYS; | |
328 | err = -ENODEV; | |
329 | list_for_each_entry(rng, &rng_list, list) { | |
d9a53b01 | 330 | if (sysfs_streq(rng->name, buf)) { |
844dd05f | 331 | err = 0; |
90ac41bd HX |
332 | if (rng != current_rng) |
333 | err = set_current_rng(rng); | |
844dd05f MB |
334 | break; |
335 | } | |
336 | } | |
337 | mutex_unlock(&rng_mutex); | |
338 | ||
339 | return err ? : len; | |
340 | } | |
341 | ||
94fbcded GKH |
342 | static ssize_t hwrng_attr_current_show(struct device *dev, |
343 | struct device_attribute *attr, | |
844dd05f MB |
344 | char *buf) |
345 | { | |
844dd05f | 346 | ssize_t ret; |
3a2c0ba5 | 347 | struct hwrng *rng; |
844dd05f | 348 | |
3a2c0ba5 RR |
349 | rng = get_current_rng(); |
350 | if (IS_ERR(rng)) | |
351 | return PTR_ERR(rng); | |
352 | ||
353 | ret = snprintf(buf, PAGE_SIZE, "%s\n", rng ? rng->name : "none"); | |
354 | put_rng(rng); | |
844dd05f MB |
355 | |
356 | return ret; | |
357 | } | |
358 | ||
94fbcded GKH |
359 | static ssize_t hwrng_attr_available_show(struct device *dev, |
360 | struct device_attribute *attr, | |
844dd05f MB |
361 | char *buf) |
362 | { | |
363 | int err; | |
844dd05f MB |
364 | struct hwrng *rng; |
365 | ||
366 | err = mutex_lock_interruptible(&rng_mutex); | |
367 | if (err) | |
368 | return -ERESTARTSYS; | |
369 | buf[0] = '\0'; | |
370 | list_for_each_entry(rng, &rng_list, list) { | |
61daf055 RS |
371 | strlcat(buf, rng->name, PAGE_SIZE); |
372 | strlcat(buf, " ", PAGE_SIZE); | |
844dd05f | 373 | } |
61daf055 | 374 | strlcat(buf, "\n", PAGE_SIZE); |
844dd05f MB |
375 | mutex_unlock(&rng_mutex); |
376 | ||
61daf055 | 377 | return strlen(buf); |
844dd05f MB |
378 | } |
379 | ||
94fbcded GKH |
380 | static DEVICE_ATTR(rng_current, S_IRUGO | S_IWUSR, |
381 | hwrng_attr_current_show, | |
382 | hwrng_attr_current_store); | |
383 | static DEVICE_ATTR(rng_available, S_IRUGO, | |
384 | hwrng_attr_available_show, | |
385 | NULL); | |
844dd05f | 386 | |
0daa7a0a TI |
387 | static struct attribute *rng_dev_attrs[] = { |
388 | &dev_attr_rng_current.attr, | |
389 | &dev_attr_rng_available.attr, | |
390 | NULL | |
391 | }; | |
392 | ||
393 | ATTRIBUTE_GROUPS(rng_dev); | |
844dd05f | 394 | |
ac3a497f | 395 | static void __exit unregister_miscdev(void) |
844dd05f | 396 | { |
b844eba2 | 397 | misc_deregister(&rng_miscdev); |
844dd05f MB |
398 | } |
399 | ||
ac3a497f | 400 | static int __init register_miscdev(void) |
844dd05f | 401 | { |
0daa7a0a | 402 | return misc_register(&rng_miscdev); |
844dd05f MB |
403 | } |
404 | ||
be4000bc TD |
405 | static int hwrng_fillfn(void *unused) |
406 | { | |
407 | long rc; | |
408 | ||
409 | while (!kthread_should_stop()) { | |
3a2c0ba5 RR |
410 | struct hwrng *rng; |
411 | ||
412 | rng = get_current_rng(); | |
413 | if (IS_ERR(rng) || !rng) | |
be4000bc | 414 | break; |
9372b35e | 415 | mutex_lock(&reading_mutex); |
3a2c0ba5 | 416 | rc = rng_get_data(rng, rng_fillbuf, |
be4000bc | 417 | rng_buffer_size(), 1); |
9372b35e | 418 | mutex_unlock(&reading_mutex); |
3a2c0ba5 | 419 | put_rng(rng); |
be4000bc TD |
420 | if (rc <= 0) { |
421 | pr_warn("hwrng: no data available\n"); | |
422 | msleep_interruptible(10000); | |
423 | continue; | |
424 | } | |
9372b35e | 425 | /* Outside lock, sure, but y'know: randomness. */ |
be4000bc | 426 | add_hwgenerator_randomness((void *)rng_fillbuf, rc, |
e02b8765 | 427 | rc * current_quality * 8 >> 10); |
be4000bc | 428 | } |
9dda727d | 429 | hwrng_fill = NULL; |
be4000bc TD |
430 | return 0; |
431 | } | |
432 | ||
433 | static void start_khwrngd(void) | |
434 | { | |
435 | hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); | |
17fb874d | 436 | if (IS_ERR(hwrng_fill)) { |
be4000bc TD |
437 | pr_err("hwrng_fill thread creation failed"); |
438 | hwrng_fill = NULL; | |
439 | } | |
440 | } | |
441 | ||
844dd05f MB |
442 | int hwrng_register(struct hwrng *rng) |
443 | { | |
844dd05f MB |
444 | int err = -EINVAL; |
445 | struct hwrng *old_rng, *tmp; | |
446 | ||
447 | if (rng->name == NULL || | |
9996508b | 448 | (rng->data_read == NULL && rng->read == NULL)) |
844dd05f MB |
449 | goto out; |
450 | ||
451 | mutex_lock(&rng_mutex); | |
452 | ||
f7f154f1 RR |
453 | /* kmalloc makes this safe for virt_to_page() in virtio_rng.c */ |
454 | err = -ENOMEM; | |
455 | if (!rng_buffer) { | |
456 | rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL); | |
457 | if (!rng_buffer) | |
458 | goto out_unlock; | |
459 | } | |
be4000bc TD |
460 | if (!rng_fillbuf) { |
461 | rng_fillbuf = kmalloc(rng_buffer_size(), GFP_KERNEL); | |
462 | if (!rng_fillbuf) { | |
463 | kfree(rng_buffer); | |
464 | goto out_unlock; | |
465 | } | |
466 | } | |
f7f154f1 | 467 | |
844dd05f MB |
468 | /* Must not register two RNGs with the same name. */ |
469 | err = -EEXIST; | |
470 | list_for_each_entry(tmp, &rng_list, list) { | |
471 | if (strcmp(tmp->name, rng->name) == 0) | |
472 | goto out_unlock; | |
473 | } | |
474 | ||
15b66cd5 HX |
475 | init_completion(&rng->cleanup_done); |
476 | complete(&rng->cleanup_done); | |
477 | ||
844dd05f | 478 | old_rng = current_rng; |
ebbbfa24 | 479 | err = 0; |
844dd05f | 480 | if (!old_rng) { |
90ac41bd | 481 | err = set_current_rng(rng); |
844dd05f MB |
482 | if (err) |
483 | goto out_unlock; | |
844dd05f | 484 | } |
844dd05f | 485 | list_add_tail(&rng->list, &rng_list); |
d9e79726 | 486 | |
d3cc7996 AS |
487 | if (old_rng && !rng->init) { |
488 | /* | |
489 | * Use a new device's input to add some randomness to | |
490 | * the system. If this rng device isn't going to be | |
491 | * used right away, its init function hasn't been | |
492 | * called yet; so only use the randomness from devices | |
493 | * that don't need an init callback. | |
494 | */ | |
495 | add_early_randomness(rng); | |
496 | } | |
497 | ||
844dd05f MB |
498 | out_unlock: |
499 | mutex_unlock(&rng_mutex); | |
500 | out: | |
501 | return err; | |
502 | } | |
503 | EXPORT_SYMBOL_GPL(hwrng_register); | |
504 | ||
b844eba2 | 505 | void hwrng_unregister(struct hwrng *rng) |
844dd05f | 506 | { |
844dd05f MB |
507 | mutex_lock(&rng_mutex); |
508 | ||
509 | list_del(&rng->list); | |
510 | if (current_rng == rng) { | |
3a2c0ba5 RR |
511 | drop_current_rng(); |
512 | if (!list_empty(&rng_list)) { | |
513 | struct hwrng *tail; | |
514 | ||
515 | tail = list_entry(rng_list.prev, struct hwrng, list); | |
516 | ||
90ac41bd | 517 | set_current_rng(tail); |
844dd05f MB |
518 | } |
519 | } | |
3a2c0ba5 | 520 | |
be4000bc | 521 | if (list_empty(&rng_list)) { |
1dacb395 | 522 | mutex_unlock(&rng_mutex); |
be4000bc TD |
523 | if (hwrng_fill) |
524 | kthread_stop(hwrng_fill); | |
1dacb395 AK |
525 | } else |
526 | mutex_unlock(&rng_mutex); | |
a027f30d | 527 | |
77584ee5 | 528 | wait_for_completion(&rng->cleanup_done); |
844dd05f | 529 | } |
b844eba2 | 530 | EXPORT_SYMBOL_GPL(hwrng_unregister); |
844dd05f | 531 | |
4d9b519c DT |
532 | static void devm_hwrng_release(struct device *dev, void *res) |
533 | { | |
534 | hwrng_unregister(*(struct hwrng **)res); | |
535 | } | |
536 | ||
537 | static int devm_hwrng_match(struct device *dev, void *res, void *data) | |
538 | { | |
539 | struct hwrng **r = res; | |
540 | ||
541 | if (WARN_ON(!r || !*r)) | |
542 | return 0; | |
543 | ||
544 | return *r == data; | |
545 | } | |
546 | ||
547 | int devm_hwrng_register(struct device *dev, struct hwrng *rng) | |
548 | { | |
549 | struct hwrng **ptr; | |
550 | int error; | |
551 | ||
552 | ptr = devres_alloc(devm_hwrng_release, sizeof(*ptr), GFP_KERNEL); | |
553 | if (!ptr) | |
554 | return -ENOMEM; | |
555 | ||
556 | error = hwrng_register(rng); | |
557 | if (error) { | |
558 | devres_free(ptr); | |
559 | return error; | |
560 | } | |
561 | ||
562 | *ptr = rng; | |
563 | devres_add(dev, ptr); | |
564 | return 0; | |
565 | } | |
566 | EXPORT_SYMBOL_GPL(devm_hwrng_register); | |
567 | ||
568 | void devm_hwrng_unregister(struct device *dev, struct hwrng *rng) | |
569 | { | |
570 | devres_release(dev, devm_hwrng_release, devm_hwrng_match, rng); | |
571 | } | |
572 | EXPORT_SYMBOL_GPL(devm_hwrng_unregister); | |
573 | ||
ac3a497f HX |
574 | static int __init hwrng_modinit(void) |
575 | { | |
576 | return register_miscdev(); | |
577 | } | |
578 | ||
579 | static void __exit hwrng_modexit(void) | |
b7d44d94 ST |
580 | { |
581 | mutex_lock(&rng_mutex); | |
582 | BUG_ON(current_rng); | |
583 | kfree(rng_buffer); | |
be4000bc | 584 | kfree(rng_fillbuf); |
b7d44d94 | 585 | mutex_unlock(&rng_mutex); |
ac3a497f HX |
586 | |
587 | unregister_miscdev(); | |
b7d44d94 ST |
588 | } |
589 | ||
ac3a497f HX |
590 | module_init(hwrng_modinit); |
591 | module_exit(hwrng_modexit); | |
844dd05f MB |
592 | |
593 | MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver"); | |
594 | MODULE_LICENSE("GPL"); |