Commit | Line | Data |
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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 | |
9372b35e | 241 | mutex_lock(&reading_mutex); |
9996508b | 242 | if (!data_avail) { |
3a2c0ba5 | 243 | bytes_read = rng_get_data(rng, rng_buffer, |
f7f154f1 | 244 | rng_buffer_size(), |
9996508b IM |
245 | !(filp->f_flags & O_NONBLOCK)); |
246 | if (bytes_read < 0) { | |
247 | err = bytes_read; | |
9372b35e | 248 | goto out_unlock_reading; |
9996508b IM |
249 | } |
250 | data_avail = bytes_read; | |
893f1128 | 251 | } |
844dd05f | 252 | |
9996508b IM |
253 | if (!data_avail) { |
254 | if (filp->f_flags & O_NONBLOCK) { | |
255 | err = -EAGAIN; | |
9372b35e | 256 | goto out_unlock_reading; |
9996508b IM |
257 | } |
258 | } else { | |
259 | len = data_avail; | |
260 | if (len > size) | |
261 | len = size; | |
262 | ||
263 | data_avail -= len; | |
264 | ||
265 | if (copy_to_user(buf + ret, rng_buffer + data_avail, | |
266 | len)) { | |
267 | err = -EFAULT; | |
9372b35e | 268 | goto out_unlock_reading; |
9996508b IM |
269 | } |
270 | ||
271 | size -= len; | |
272 | ret += len; | |
844dd05f MB |
273 | } |
274 | ||
9372b35e | 275 | mutex_unlock(&reading_mutex); |
3a2c0ba5 | 276 | put_rng(rng); |
9996508b | 277 | |
844dd05f MB |
278 | if (need_resched()) |
279 | schedule_timeout_interruptible(1); | |
9996508b IM |
280 | |
281 | if (signal_pending(current)) { | |
282 | err = -ERESTARTSYS; | |
844dd05f | 283 | goto out; |
9996508b | 284 | } |
844dd05f MB |
285 | } |
286 | out: | |
287 | return ret ? : err; | |
3a2c0ba5 | 288 | |
9372b35e RR |
289 | out_unlock_reading: |
290 | mutex_unlock(&reading_mutex); | |
3a2c0ba5 RR |
291 | put_rng(rng); |
292 | goto out; | |
844dd05f MB |
293 | } |
294 | ||
295 | ||
62322d25 | 296 | static const struct file_operations rng_chrdev_ops = { |
844dd05f MB |
297 | .owner = THIS_MODULE, |
298 | .open = rng_dev_open, | |
299 | .read = rng_dev_read, | |
6038f373 | 300 | .llseek = noop_llseek, |
844dd05f MB |
301 | }; |
302 | ||
303 | static struct miscdevice rng_miscdev = { | |
304 | .minor = RNG_MISCDEV_MINOR, | |
305 | .name = RNG_MODULE_NAME, | |
e454cea2 | 306 | .nodename = "hwrng", |
844dd05f MB |
307 | .fops = &rng_chrdev_ops, |
308 | }; | |
309 | ||
310 | ||
94fbcded GKH |
311 | static ssize_t hwrng_attr_current_store(struct device *dev, |
312 | struct device_attribute *attr, | |
844dd05f MB |
313 | const char *buf, size_t len) |
314 | { | |
315 | int err; | |
316 | struct hwrng *rng; | |
317 | ||
318 | err = mutex_lock_interruptible(&rng_mutex); | |
319 | if (err) | |
320 | return -ERESTARTSYS; | |
321 | err = -ENODEV; | |
322 | list_for_each_entry(rng, &rng_list, list) { | |
323 | if (strcmp(rng->name, buf) == 0) { | |
844dd05f | 324 | err = 0; |
90ac41bd HX |
325 | if (rng != current_rng) |
326 | err = set_current_rng(rng); | |
844dd05f MB |
327 | break; |
328 | } | |
329 | } | |
330 | mutex_unlock(&rng_mutex); | |
331 | ||
332 | return err ? : len; | |
333 | } | |
334 | ||
94fbcded GKH |
335 | static ssize_t hwrng_attr_current_show(struct device *dev, |
336 | struct device_attribute *attr, | |
844dd05f MB |
337 | char *buf) |
338 | { | |
844dd05f | 339 | ssize_t ret; |
3a2c0ba5 | 340 | struct hwrng *rng; |
844dd05f | 341 | |
3a2c0ba5 RR |
342 | rng = get_current_rng(); |
343 | if (IS_ERR(rng)) | |
344 | return PTR_ERR(rng); | |
345 | ||
346 | ret = snprintf(buf, PAGE_SIZE, "%s\n", rng ? rng->name : "none"); | |
347 | put_rng(rng); | |
844dd05f MB |
348 | |
349 | return ret; | |
350 | } | |
351 | ||
94fbcded GKH |
352 | static ssize_t hwrng_attr_available_show(struct device *dev, |
353 | struct device_attribute *attr, | |
844dd05f MB |
354 | char *buf) |
355 | { | |
356 | int err; | |
844dd05f MB |
357 | struct hwrng *rng; |
358 | ||
359 | err = mutex_lock_interruptible(&rng_mutex); | |
360 | if (err) | |
361 | return -ERESTARTSYS; | |
362 | buf[0] = '\0'; | |
363 | list_for_each_entry(rng, &rng_list, list) { | |
61daf055 RS |
364 | strlcat(buf, rng->name, PAGE_SIZE); |
365 | strlcat(buf, " ", PAGE_SIZE); | |
844dd05f | 366 | } |
61daf055 | 367 | strlcat(buf, "\n", PAGE_SIZE); |
844dd05f MB |
368 | mutex_unlock(&rng_mutex); |
369 | ||
61daf055 | 370 | return strlen(buf); |
844dd05f MB |
371 | } |
372 | ||
94fbcded GKH |
373 | static DEVICE_ATTR(rng_current, S_IRUGO | S_IWUSR, |
374 | hwrng_attr_current_show, | |
375 | hwrng_attr_current_store); | |
376 | static DEVICE_ATTR(rng_available, S_IRUGO, | |
377 | hwrng_attr_available_show, | |
378 | NULL); | |
844dd05f MB |
379 | |
380 | ||
ac3a497f | 381 | static void __exit unregister_miscdev(void) |
844dd05f | 382 | { |
94fbcded GKH |
383 | device_remove_file(rng_miscdev.this_device, &dev_attr_rng_available); |
384 | device_remove_file(rng_miscdev.this_device, &dev_attr_rng_current); | |
b844eba2 | 385 | misc_deregister(&rng_miscdev); |
844dd05f MB |
386 | } |
387 | ||
ac3a497f | 388 | static int __init register_miscdev(void) |
844dd05f MB |
389 | { |
390 | int err; | |
391 | ||
392 | err = misc_register(&rng_miscdev); | |
393 | if (err) | |
394 | goto out; | |
94fbcded GKH |
395 | err = device_create_file(rng_miscdev.this_device, |
396 | &dev_attr_rng_current); | |
844dd05f MB |
397 | if (err) |
398 | goto err_misc_dereg; | |
94fbcded GKH |
399 | err = device_create_file(rng_miscdev.this_device, |
400 | &dev_attr_rng_available); | |
844dd05f MB |
401 | if (err) |
402 | goto err_remove_current; | |
403 | out: | |
404 | return err; | |
405 | ||
406 | err_remove_current: | |
94fbcded | 407 | device_remove_file(rng_miscdev.this_device, &dev_attr_rng_current); |
844dd05f MB |
408 | err_misc_dereg: |
409 | misc_deregister(&rng_miscdev); | |
410 | goto out; | |
411 | } | |
412 | ||
be4000bc TD |
413 | static int hwrng_fillfn(void *unused) |
414 | { | |
415 | long rc; | |
416 | ||
417 | while (!kthread_should_stop()) { | |
3a2c0ba5 RR |
418 | struct hwrng *rng; |
419 | ||
420 | rng = get_current_rng(); | |
421 | if (IS_ERR(rng) || !rng) | |
be4000bc | 422 | break; |
9372b35e | 423 | mutex_lock(&reading_mutex); |
3a2c0ba5 | 424 | rc = rng_get_data(rng, rng_fillbuf, |
be4000bc | 425 | rng_buffer_size(), 1); |
9372b35e | 426 | mutex_unlock(&reading_mutex); |
3a2c0ba5 | 427 | put_rng(rng); |
be4000bc TD |
428 | if (rc <= 0) { |
429 | pr_warn("hwrng: no data available\n"); | |
430 | msleep_interruptible(10000); | |
431 | continue; | |
432 | } | |
9372b35e | 433 | /* Outside lock, sure, but y'know: randomness. */ |
be4000bc | 434 | add_hwgenerator_randomness((void *)rng_fillbuf, rc, |
e02b8765 | 435 | rc * current_quality * 8 >> 10); |
be4000bc | 436 | } |
9dda727d | 437 | hwrng_fill = NULL; |
be4000bc TD |
438 | return 0; |
439 | } | |
440 | ||
441 | static void start_khwrngd(void) | |
442 | { | |
443 | hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); | |
444 | if (hwrng_fill == ERR_PTR(-ENOMEM)) { | |
445 | pr_err("hwrng_fill thread creation failed"); | |
446 | hwrng_fill = NULL; | |
447 | } | |
448 | } | |
449 | ||
844dd05f MB |
450 | int hwrng_register(struct hwrng *rng) |
451 | { | |
844dd05f MB |
452 | int err = -EINVAL; |
453 | struct hwrng *old_rng, *tmp; | |
454 | ||
455 | if (rng->name == NULL || | |
9996508b | 456 | (rng->data_read == NULL && rng->read == NULL)) |
844dd05f MB |
457 | goto out; |
458 | ||
459 | mutex_lock(&rng_mutex); | |
460 | ||
f7f154f1 RR |
461 | /* kmalloc makes this safe for virt_to_page() in virtio_rng.c */ |
462 | err = -ENOMEM; | |
463 | if (!rng_buffer) { | |
464 | rng_buffer = kmalloc(rng_buffer_size(), GFP_KERNEL); | |
465 | if (!rng_buffer) | |
466 | goto out_unlock; | |
467 | } | |
be4000bc TD |
468 | if (!rng_fillbuf) { |
469 | rng_fillbuf = kmalloc(rng_buffer_size(), GFP_KERNEL); | |
470 | if (!rng_fillbuf) { | |
471 | kfree(rng_buffer); | |
472 | goto out_unlock; | |
473 | } | |
474 | } | |
f7f154f1 | 475 | |
844dd05f MB |
476 | /* Must not register two RNGs with the same name. */ |
477 | err = -EEXIST; | |
478 | list_for_each_entry(tmp, &rng_list, list) { | |
479 | if (strcmp(tmp->name, rng->name) == 0) | |
480 | goto out_unlock; | |
481 | } | |
482 | ||
15b66cd5 HX |
483 | init_completion(&rng->cleanup_done); |
484 | complete(&rng->cleanup_done); | |
485 | ||
844dd05f | 486 | old_rng = current_rng; |
ebbbfa24 | 487 | err = 0; |
844dd05f | 488 | if (!old_rng) { |
90ac41bd | 489 | err = set_current_rng(rng); |
844dd05f MB |
490 | if (err) |
491 | goto out_unlock; | |
844dd05f | 492 | } |
844dd05f | 493 | list_add_tail(&rng->list, &rng_list); |
d9e79726 | 494 | |
d3cc7996 AS |
495 | if (old_rng && !rng->init) { |
496 | /* | |
497 | * Use a new device's input to add some randomness to | |
498 | * the system. If this rng device isn't going to be | |
499 | * used right away, its init function hasn't been | |
500 | * called yet; so only use the randomness from devices | |
501 | * that don't need an init callback. | |
502 | */ | |
503 | add_early_randomness(rng); | |
504 | } | |
505 | ||
844dd05f MB |
506 | out_unlock: |
507 | mutex_unlock(&rng_mutex); | |
508 | out: | |
509 | return err; | |
510 | } | |
511 | EXPORT_SYMBOL_GPL(hwrng_register); | |
512 | ||
b844eba2 | 513 | void hwrng_unregister(struct hwrng *rng) |
844dd05f | 514 | { |
844dd05f MB |
515 | mutex_lock(&rng_mutex); |
516 | ||
517 | list_del(&rng->list); | |
518 | if (current_rng == rng) { | |
3a2c0ba5 RR |
519 | drop_current_rng(); |
520 | if (!list_empty(&rng_list)) { | |
521 | struct hwrng *tail; | |
522 | ||
523 | tail = list_entry(rng_list.prev, struct hwrng, list); | |
524 | ||
90ac41bd | 525 | set_current_rng(tail); |
844dd05f MB |
526 | } |
527 | } | |
3a2c0ba5 | 528 | |
be4000bc | 529 | if (list_empty(&rng_list)) { |
1dacb395 | 530 | mutex_unlock(&rng_mutex); |
be4000bc TD |
531 | if (hwrng_fill) |
532 | kthread_stop(hwrng_fill); | |
1dacb395 AK |
533 | } else |
534 | mutex_unlock(&rng_mutex); | |
a027f30d | 535 | |
77584ee5 | 536 | wait_for_completion(&rng->cleanup_done); |
844dd05f | 537 | } |
b844eba2 | 538 | EXPORT_SYMBOL_GPL(hwrng_unregister); |
844dd05f | 539 | |
4d9b519c DT |
540 | static void devm_hwrng_release(struct device *dev, void *res) |
541 | { | |
542 | hwrng_unregister(*(struct hwrng **)res); | |
543 | } | |
544 | ||
545 | static int devm_hwrng_match(struct device *dev, void *res, void *data) | |
546 | { | |
547 | struct hwrng **r = res; | |
548 | ||
549 | if (WARN_ON(!r || !*r)) | |
550 | return 0; | |
551 | ||
552 | return *r == data; | |
553 | } | |
554 | ||
555 | int devm_hwrng_register(struct device *dev, struct hwrng *rng) | |
556 | { | |
557 | struct hwrng **ptr; | |
558 | int error; | |
559 | ||
560 | ptr = devres_alloc(devm_hwrng_release, sizeof(*ptr), GFP_KERNEL); | |
561 | if (!ptr) | |
562 | return -ENOMEM; | |
563 | ||
564 | error = hwrng_register(rng); | |
565 | if (error) { | |
566 | devres_free(ptr); | |
567 | return error; | |
568 | } | |
569 | ||
570 | *ptr = rng; | |
571 | devres_add(dev, ptr); | |
572 | return 0; | |
573 | } | |
574 | EXPORT_SYMBOL_GPL(devm_hwrng_register); | |
575 | ||
576 | void devm_hwrng_unregister(struct device *dev, struct hwrng *rng) | |
577 | { | |
578 | devres_release(dev, devm_hwrng_release, devm_hwrng_match, rng); | |
579 | } | |
580 | EXPORT_SYMBOL_GPL(devm_hwrng_unregister); | |
581 | ||
ac3a497f HX |
582 | static int __init hwrng_modinit(void) |
583 | { | |
584 | return register_miscdev(); | |
585 | } | |
586 | ||
587 | static void __exit hwrng_modexit(void) | |
b7d44d94 ST |
588 | { |
589 | mutex_lock(&rng_mutex); | |
590 | BUG_ON(current_rng); | |
591 | kfree(rng_buffer); | |
be4000bc | 592 | kfree(rng_fillbuf); |
b7d44d94 | 593 | mutex_unlock(&rng_mutex); |
ac3a497f HX |
594 | |
595 | unregister_miscdev(); | |
b7d44d94 ST |
596 | } |
597 | ||
ac3a497f HX |
598 | module_init(hwrng_modinit); |
599 | module_exit(hwrng_modexit); | |
844dd05f MB |
600 | |
601 | MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver"); | |
602 | MODULE_LICENSE("GPL"); |