1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Common functions for kernel modules using Dell SMBIOS
4 *
5 * Copyright (c) Red Hat <mjg@redhat.com>
6 * Copyright (c) 2014 Gabriele Mazzotta <gabriele.mzt@gmail.com>
7 * Copyright (c) 2014 Pali Rohár <pali@kernel.org>
8 *
9 * Based on documentation in the libsmbios package:
10 * Copyright (C) 2005-2014 Dell Inc.
11 */
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/capability.h>
17 #include <linux/dmi.h>
18 #include <linux/err.h>
19 #include <linux/mutex.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include "dell-smbios.h"
23
24 static u32 da_supported_commands;
25 static int da_num_tokens;
26 static struct platform_device *platform_device;
27 static struct calling_interface_token *da_tokens;
28 static struct device_attribute *token_location_attrs;
29 static struct device_attribute *token_value_attrs;
30 static struct attribute **token_attrs;
31 static DEFINE_MUTEX(smbios_mutex);
32
33 struct smbios_device {
34 struct list_head list;
35 struct device *device;
36 int (*call_fn)(struct calling_interface_buffer *arg);
37 };
38
39 struct smbios_call {
40 u32 need_capability;
41 int cmd_class;
42 int cmd_select;
43 };
44
45 /* calls that are whitelisted for given capabilities */
46 static struct smbios_call call_whitelist[] = {
47 /* generally tokens are allowed, but may be further filtered or
48 * restricted by token blacklist or whitelist
49 */
50 {CAP_SYS_ADMIN, CLASS_TOKEN_READ, SELECT_TOKEN_STD},
51 {CAP_SYS_ADMIN, CLASS_TOKEN_READ, SELECT_TOKEN_AC},
52 {CAP_SYS_ADMIN, CLASS_TOKEN_READ, SELECT_TOKEN_BAT},
53 {CAP_SYS_ADMIN, CLASS_TOKEN_WRITE, SELECT_TOKEN_STD},
54 {CAP_SYS_ADMIN, CLASS_TOKEN_WRITE, SELECT_TOKEN_AC},
55 {CAP_SYS_ADMIN, CLASS_TOKEN_WRITE, SELECT_TOKEN_BAT},
56 /* used by userspace: fwupdate */
57 {CAP_SYS_ADMIN, CLASS_ADMIN_PROP, SELECT_ADMIN_PROP},
58 /* used by userspace: fwupd */
59 {CAP_SYS_ADMIN, CLASS_INFO, SELECT_DOCK},
60 {CAP_SYS_ADMIN, CLASS_FLASH_INTERFACE, SELECT_FLASH_INTERFACE},
61 };
62
63 /* calls that are explicitly blacklisted */
64 static struct smbios_call call_blacklist[] = {
65 {0x0000, 1, 7}, /* manufacturing use */
66 {0x0000, 6, 5}, /* manufacturing use */
67 {0x0000, 11, 3}, /* write once */
68 {0x0000, 11, 7}, /* write once */
69 {0x0000, 11, 11}, /* write once */
70 {0x0000, 19, -1}, /* diagnostics */
71 /* handled by kernel: dell-laptop */
72 {0x0000, CLASS_INFO, SELECT_RFKILL},
73 {0x0000, CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT},
74 };
75
76 struct token_range {
77 u32 need_capability;
78 u16 min;
79 u16 max;
80 };
81
82 /* tokens that are whitelisted for given capabilities */
83 static struct token_range token_whitelist[] = {
84 /* used by userspace: fwupdate */
85 {CAP_SYS_ADMIN, CAPSULE_EN_TOKEN, CAPSULE_DIS_TOKEN},
86 /* can indicate to userspace that WMI is needed */
87 {0x0000, WSMT_EN_TOKEN, WSMT_DIS_TOKEN}
88 };
89
90 /* tokens that are explicitly blacklisted */
91 static struct token_range token_blacklist[] = {
92 {0x0000, 0x0058, 0x0059}, /* ME use */
93 {0x0000, 0x00CD, 0x00D0}, /* raid shadow copy */
94 {0x0000, 0x013A, 0x01FF}, /* sata shadow copy */
95 {0x0000, 0x0175, 0x0176}, /* write once */
96 {0x0000, 0x0195, 0x0197}, /* diagnostics */
97 {0x0000, 0x01DC, 0x01DD}, /* manufacturing use */
98 {0x0000, 0x027D, 0x0284}, /* diagnostics */
99 {0x0000, 0x02E3, 0x02E3}, /* manufacturing use */
100 {0x0000, 0x02FF, 0x02FF}, /* manufacturing use */
101 {0x0000, 0x0300, 0x0302}, /* manufacturing use */
102 {0x0000, 0x0325, 0x0326}, /* manufacturing use */
103 {0x0000, 0x0332, 0x0335}, /* fan control */
104 {0x0000, 0x0350, 0x0350}, /* manufacturing use */
105 {0x0000, 0x0363, 0x0363}, /* manufacturing use */
106 {0x0000, 0x0368, 0x0368}, /* manufacturing use */
107 {0x0000, 0x03F6, 0x03F7}, /* manufacturing use */
108 {0x0000, 0x049E, 0x049F}, /* manufacturing use */
109 {0x0000, 0x04A0, 0x04A3}, /* disagnostics */
110 {0x0000, 0x04E6, 0x04E7}, /* manufacturing use */
111 {0x0000, 0x4000, 0x7FFF}, /* internal BIOS use */
112 {0x0000, 0x9000, 0x9001}, /* internal BIOS use */
113 {0x0000, 0xA000, 0xBFFF}, /* write only */
114 {0x0000, 0xEFF0, 0xEFFF}, /* internal BIOS use */
115 /* handled by kernel: dell-laptop */
116 {0x0000, BRIGHTNESS_TOKEN, BRIGHTNESS_TOKEN},
117 {0x0000, KBD_LED_OFF_TOKEN, KBD_LED_AUTO_TOKEN},
118 {0x0000, KBD_LED_AC_TOKEN, KBD_LED_AC_TOKEN},
119 {0x0000, KBD_LED_AUTO_25_TOKEN, KBD_LED_AUTO_75_TOKEN},
120 {0x0000, KBD_LED_AUTO_100_TOKEN, KBD_LED_AUTO_100_TOKEN},
121 {0x0000, GLOBAL_MIC_MUTE_ENABLE, GLOBAL_MIC_MUTE_DISABLE},
122 };
123
124 static LIST_HEAD(smbios_device_list);
125
dell_smbios_error(int value)126 int dell_smbios_error(int value)
127 {
128 switch (value) {
129 case 0: /* Completed successfully */
130 return 0;
131 case -1: /* Completed with error */
132 return -EIO;
133 case -2: /* Function not supported */
134 return -ENXIO;
135 default: /* Unknown error */
136 return -EINVAL;
137 }
138 }
139 EXPORT_SYMBOL_GPL(dell_smbios_error);
140
dell_smbios_register_device(struct device * d,void * call_fn)141 int dell_smbios_register_device(struct device *d, void *call_fn)
142 {
143 struct smbios_device *priv;
144
145 priv = devm_kzalloc(d, sizeof(struct smbios_device), GFP_KERNEL);
146 if (!priv)
147 return -ENOMEM;
148 get_device(d);
149 priv->device = d;
150 priv->call_fn = call_fn;
151 mutex_lock(&smbios_mutex);
152 list_add_tail(&priv->list, &smbios_device_list);
153 mutex_unlock(&smbios_mutex);
154 dev_dbg(d, "Added device: %s\n", d->driver->name);
155 return 0;
156 }
157 EXPORT_SYMBOL_GPL(dell_smbios_register_device);
158
dell_smbios_unregister_device(struct device * d)159 void dell_smbios_unregister_device(struct device *d)
160 {
161 struct smbios_device *priv;
162
163 mutex_lock(&smbios_mutex);
164 list_for_each_entry(priv, &smbios_device_list, list) {
165 if (priv->device == d) {
166 list_del(&priv->list);
167 put_device(d);
168 break;
169 }
170 }
171 mutex_unlock(&smbios_mutex);
172 dev_dbg(d, "Remove device: %s\n", d->driver->name);
173 }
174 EXPORT_SYMBOL_GPL(dell_smbios_unregister_device);
175
dell_smbios_call_filter(struct device * d,struct calling_interface_buffer * buffer)176 int dell_smbios_call_filter(struct device *d,
177 struct calling_interface_buffer *buffer)
178 {
179 u16 t = 0;
180 int i;
181
182 /* can't make calls over 30 */
183 if (buffer->cmd_class > 30) {
184 dev_dbg(d, "class too big: %u\n", buffer->cmd_class);
185 return -EINVAL;
186 }
187
188 /* supported calls on the particular system */
189 if (!(da_supported_commands & (1 << buffer->cmd_class))) {
190 dev_dbg(d, "invalid command, supported commands: 0x%8x\n",
191 da_supported_commands);
192 return -EINVAL;
193 }
194
195 /* match against call blacklist */
196 for (i = 0; i < ARRAY_SIZE(call_blacklist); i++) {
197 if (buffer->cmd_class != call_blacklist[i].cmd_class)
198 continue;
199 if (buffer->cmd_select != call_blacklist[i].cmd_select &&
200 call_blacklist[i].cmd_select != -1)
201 continue;
202 dev_dbg(d, "blacklisted command: %u/%u\n",
203 buffer->cmd_class, buffer->cmd_select);
204 return -EINVAL;
205 }
206
207 /* if a token call, find token ID */
208
209 if ((buffer->cmd_class == CLASS_TOKEN_READ ||
210 buffer->cmd_class == CLASS_TOKEN_WRITE) &&
211 buffer->cmd_select < 3) {
212 /* tokens enabled ? */
213 if (!da_tokens) {
214 dev_dbg(d, "no token support on this system\n");
215 return -EINVAL;
216 }
217
218 /* find the matching token ID */
219 for (i = 0; i < da_num_tokens; i++) {
220 if (da_tokens[i].location != buffer->input[0])
221 continue;
222 t = da_tokens[i].tokenID;
223 break;
224 }
225
226 /* token call; but token didn't exist */
227 if (!t) {
228 dev_dbg(d, "token at location %04x doesn't exist\n",
229 buffer->input[0]);
230 return -EINVAL;
231 }
232
233 /* match against token blacklist */
234 for (i = 0; i < ARRAY_SIZE(token_blacklist); i++) {
235 if (!token_blacklist[i].min || !token_blacklist[i].max)
236 continue;
237 if (t >= token_blacklist[i].min &&
238 t <= token_blacklist[i].max)
239 return -EINVAL;
240 }
241
242 /* match against token whitelist */
243 for (i = 0; i < ARRAY_SIZE(token_whitelist); i++) {
244 if (!token_whitelist[i].min || !token_whitelist[i].max)
245 continue;
246 if (t < token_whitelist[i].min ||
247 t > token_whitelist[i].max)
248 continue;
249 if (!token_whitelist[i].need_capability ||
250 capable(token_whitelist[i].need_capability)) {
251 dev_dbg(d, "whitelisted token: %x\n", t);
252 return 0;
253 }
254
255 }
256 }
257 /* match against call whitelist */
258 for (i = 0; i < ARRAY_SIZE(call_whitelist); i++) {
259 if (buffer->cmd_class != call_whitelist[i].cmd_class)
260 continue;
261 if (buffer->cmd_select != call_whitelist[i].cmd_select)
262 continue;
263 if (!call_whitelist[i].need_capability ||
264 capable(call_whitelist[i].need_capability)) {
265 dev_dbg(d, "whitelisted capable command: %u/%u\n",
266 buffer->cmd_class, buffer->cmd_select);
267 return 0;
268 }
269 dev_dbg(d, "missing capability %d for %u/%u\n",
270 call_whitelist[i].need_capability,
271 buffer->cmd_class, buffer->cmd_select);
272
273 }
274
275 /* not in a whitelist, only allow processes with capabilities */
276 if (capable(CAP_SYS_RAWIO)) {
277 dev_dbg(d, "Allowing %u/%u due to CAP_SYS_RAWIO\n",
278 buffer->cmd_class, buffer->cmd_select);
279 return 0;
280 }
281
282 return -EACCES;
283 }
284 EXPORT_SYMBOL_GPL(dell_smbios_call_filter);
285
dell_smbios_call(struct calling_interface_buffer * buffer)286 int dell_smbios_call(struct calling_interface_buffer *buffer)
287 {
288 int (*call_fn)(struct calling_interface_buffer *) = NULL;
289 struct device *selected_dev = NULL;
290 struct smbios_device *priv;
291 int ret;
292
293 mutex_lock(&smbios_mutex);
294 list_for_each_entry(priv, &smbios_device_list, list) {
295 if (!selected_dev || priv->device->id >= selected_dev->id) {
296 dev_dbg(priv->device, "Trying device ID: %d\n",
297 priv->device->id);
298 call_fn = priv->call_fn;
299 selected_dev = priv->device;
300 }
301 }
302
303 if (!selected_dev) {
304 ret = -ENODEV;
305 pr_err("No dell-smbios drivers are loaded\n");
306 goto out_smbios_call;
307 }
308
309 ret = call_fn(buffer);
310
311 out_smbios_call:
312 mutex_unlock(&smbios_mutex);
313 return ret;
314 }
315 EXPORT_SYMBOL_GPL(dell_smbios_call);
316
dell_smbios_find_token(int tokenid)317 struct calling_interface_token *dell_smbios_find_token(int tokenid)
318 {
319 int i;
320
321 if (!da_tokens)
322 return NULL;
323
324 for (i = 0; i < da_num_tokens; i++) {
325 if (da_tokens[i].tokenID == tokenid)
326 return &da_tokens[i];
327 }
328
329 return NULL;
330 }
331 EXPORT_SYMBOL_GPL(dell_smbios_find_token);
332
333 static BLOCKING_NOTIFIER_HEAD(dell_laptop_chain_head);
334
dell_laptop_register_notifier(struct notifier_block * nb)335 int dell_laptop_register_notifier(struct notifier_block *nb)
336 {
337 return blocking_notifier_chain_register(&dell_laptop_chain_head, nb);
338 }
339 EXPORT_SYMBOL_GPL(dell_laptop_register_notifier);
340
dell_laptop_unregister_notifier(struct notifier_block * nb)341 int dell_laptop_unregister_notifier(struct notifier_block *nb)
342 {
343 return blocking_notifier_chain_unregister(&dell_laptop_chain_head, nb);
344 }
345 EXPORT_SYMBOL_GPL(dell_laptop_unregister_notifier);
346
dell_laptop_call_notifier(unsigned long action,void * data)347 void dell_laptop_call_notifier(unsigned long action, void *data)
348 {
349 blocking_notifier_call_chain(&dell_laptop_chain_head, action, data);
350 }
351 EXPORT_SYMBOL_GPL(dell_laptop_call_notifier);
352
parse_da_table(const struct dmi_header * dm)353 static void __init parse_da_table(const struct dmi_header *dm)
354 {
355 /* Final token is a terminator, so we don't want to copy it */
356 int tokens = (dm->length-11)/sizeof(struct calling_interface_token)-1;
357 struct calling_interface_token *new_da_tokens;
358 struct calling_interface_structure *table =
359 container_of(dm, struct calling_interface_structure, header);
360
361 /*
362 * 4 bytes of table header, plus 7 bytes of Dell header
363 * plus at least 6 bytes of entry
364 */
365
366 if (dm->length < 17)
367 return;
368
369 da_supported_commands = table->supportedCmds;
370
371 new_da_tokens = krealloc(da_tokens, (da_num_tokens + tokens) *
372 sizeof(struct calling_interface_token),
373 GFP_KERNEL);
374
375 if (!new_da_tokens)
376 return;
377 da_tokens = new_da_tokens;
378
379 memcpy(da_tokens+da_num_tokens, table->tokens,
380 sizeof(struct calling_interface_token) * tokens);
381
382 da_num_tokens += tokens;
383 }
384
zero_duplicates(struct device * dev)385 static void zero_duplicates(struct device *dev)
386 {
387 int i, j;
388
389 for (i = 0; i < da_num_tokens; i++) {
390 if (da_tokens[i].tokenID == 0)
391 continue;
392 for (j = i+1; j < da_num_tokens; j++) {
393 if (da_tokens[j].tokenID == 0)
394 continue;
395 if (da_tokens[i].tokenID == da_tokens[j].tokenID) {
396 dev_dbg(dev, "Zeroing dup token ID %x(%x/%x)\n",
397 da_tokens[j].tokenID,
398 da_tokens[j].location,
399 da_tokens[j].value);
400 da_tokens[j].tokenID = 0;
401 }
402 }
403 }
404 }
405
find_tokens(const struct dmi_header * dm,void * dummy)406 static void __init find_tokens(const struct dmi_header *dm, void *dummy)
407 {
408 switch (dm->type) {
409 case 0xd4: /* Indexed IO */
410 case 0xd5: /* Protected Area Type 1 */
411 case 0xd6: /* Protected Area Type 2 */
412 break;
413 case 0xda: /* Calling interface */
414 parse_da_table(dm);
415 break;
416 }
417 }
418
match_attribute(struct device * dev,struct device_attribute * attr)419 static int match_attribute(struct device *dev,
420 struct device_attribute *attr)
421 {
422 int i;
423
424 for (i = 0; i < da_num_tokens * 2; i++) {
425 if (!token_attrs[i])
426 continue;
427 if (strcmp(token_attrs[i]->name, attr->attr.name) == 0)
428 return i/2;
429 }
430 dev_dbg(dev, "couldn't match: %s\n", attr->attr.name);
431 return -EINVAL;
432 }
433
location_show(struct device * dev,struct device_attribute * attr,char * buf)434 static ssize_t location_show(struct device *dev,
435 struct device_attribute *attr, char *buf)
436 {
437 int i;
438
439 if (!capable(CAP_SYS_ADMIN))
440 return -EPERM;
441
442 i = match_attribute(dev, attr);
443 if (i > 0)
444 return scnprintf(buf, PAGE_SIZE, "%08x", da_tokens[i].location);
445 return 0;
446 }
447
value_show(struct device * dev,struct device_attribute * attr,char * buf)448 static ssize_t value_show(struct device *dev,
449 struct device_attribute *attr, char *buf)
450 {
451 int i;
452
453 if (!capable(CAP_SYS_ADMIN))
454 return -EPERM;
455
456 i = match_attribute(dev, attr);
457 if (i > 0)
458 return scnprintf(buf, PAGE_SIZE, "%08x", da_tokens[i].value);
459 return 0;
460 }
461
462 static struct attribute_group smbios_attribute_group = {
463 .name = "tokens"
464 };
465
466 static struct platform_driver platform_driver = {
467 .driver = {
468 .name = "dell-smbios",
469 },
470 };
471
build_tokens_sysfs(struct platform_device * dev)472 static int build_tokens_sysfs(struct platform_device *dev)
473 {
474 char *location_name;
475 char *value_name;
476 size_t size;
477 int ret;
478 int i, j;
479
480 /* (number of tokens + 1 for null terminated */
481 size = sizeof(struct device_attribute) * (da_num_tokens + 1);
482 token_location_attrs = kzalloc(size, GFP_KERNEL);
483 if (!token_location_attrs)
484 return -ENOMEM;
485 token_value_attrs = kzalloc(size, GFP_KERNEL);
486 if (!token_value_attrs)
487 goto out_allocate_value;
488
489 /* need to store both location and value + terminator*/
490 size = sizeof(struct attribute *) * ((2 * da_num_tokens) + 1);
491 token_attrs = kzalloc(size, GFP_KERNEL);
492 if (!token_attrs)
493 goto out_allocate_attrs;
494
495 for (i = 0, j = 0; i < da_num_tokens; i++) {
496 /* skip empty */
497 if (da_tokens[i].tokenID == 0)
498 continue;
499 /* add location */
500 location_name = kasprintf(GFP_KERNEL, "%04x_location",
501 da_tokens[i].tokenID);
502 if (location_name == NULL)
503 goto out_unwind_strings;
504 sysfs_attr_init(&token_location_attrs[i].attr);
505 token_location_attrs[i].attr.name = location_name;
506 token_location_attrs[i].attr.mode = 0444;
507 token_location_attrs[i].show = location_show;
508 token_attrs[j++] = &token_location_attrs[i].attr;
509
510 /* add value */
511 value_name = kasprintf(GFP_KERNEL, "%04x_value",
512 da_tokens[i].tokenID);
513 if (value_name == NULL)
514 goto loop_fail_create_value;
515 sysfs_attr_init(&token_value_attrs[i].attr);
516 token_value_attrs[i].attr.name = value_name;
517 token_value_attrs[i].attr.mode = 0444;
518 token_value_attrs[i].show = value_show;
519 token_attrs[j++] = &token_value_attrs[i].attr;
520 continue;
521
522 loop_fail_create_value:
523 kfree(location_name);
524 goto out_unwind_strings;
525 }
526 smbios_attribute_group.attrs = token_attrs;
527
528 ret = sysfs_create_group(&dev->dev.kobj, &smbios_attribute_group);
529 if (ret)
530 goto out_unwind_strings;
531 return 0;
532
533 out_unwind_strings:
534 while (i--) {
535 kfree(token_location_attrs[i].attr.name);
536 kfree(token_value_attrs[i].attr.name);
537 }
538 kfree(token_attrs);
539 out_allocate_attrs:
540 kfree(token_value_attrs);
541 out_allocate_value:
542 kfree(token_location_attrs);
543
544 return -ENOMEM;
545 }
546
free_group(struct platform_device * pdev)547 static void free_group(struct platform_device *pdev)
548 {
549 int i;
550
551 sysfs_remove_group(&pdev->dev.kobj,
552 &smbios_attribute_group);
553 for (i = 0; i < da_num_tokens; i++) {
554 kfree(token_location_attrs[i].attr.name);
555 kfree(token_value_attrs[i].attr.name);
556 }
557 kfree(token_attrs);
558 kfree(token_value_attrs);
559 kfree(token_location_attrs);
560 }
561
dell_smbios_init(void)562 static int __init dell_smbios_init(void)
563 {
564 int ret, wmi, smm;
565
566 if (!dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL) &&
567 !dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "www.dell.com", NULL)) {
568 pr_err("Unable to run on non-Dell system\n");
569 return -ENODEV;
570 }
571
572 dmi_walk(find_tokens, NULL);
573
574 ret = platform_driver_register(&platform_driver);
575 if (ret)
576 goto fail_platform_driver;
577
578 platform_device = platform_device_alloc("dell-smbios", 0);
579 if (!platform_device) {
580 ret = -ENOMEM;
581 goto fail_platform_device_alloc;
582 }
583 ret = platform_device_add(platform_device);
584 if (ret)
585 goto fail_platform_device_add;
586
587 /* register backends */
588 wmi = init_dell_smbios_wmi();
589 if (wmi)
590 pr_debug("Failed to initialize WMI backend: %d\n", wmi);
591 smm = init_dell_smbios_smm();
592 if (smm)
593 pr_debug("Failed to initialize SMM backend: %d\n", smm);
594 if (wmi && smm) {
595 pr_err("No SMBIOS backends available (wmi: %d, smm: %d)\n",
596 wmi, smm);
597 ret = -ENODEV;
598 goto fail_create_group;
599 }
600
601 if (da_tokens) {
602 /* duplicate tokens will cause problems building sysfs files */
603 zero_duplicates(&platform_device->dev);
604
605 ret = build_tokens_sysfs(platform_device);
606 if (ret)
607 goto fail_sysfs;
608 }
609
610 return 0;
611
612 fail_sysfs:
613 free_group(platform_device);
614
615 fail_create_group:
616 platform_device_del(platform_device);
617
618 fail_platform_device_add:
619 platform_device_put(platform_device);
620
621 fail_platform_device_alloc:
622 platform_driver_unregister(&platform_driver);
623
624 fail_platform_driver:
625 kfree(da_tokens);
626 return ret;
627 }
628
dell_smbios_exit(void)629 static void __exit dell_smbios_exit(void)
630 {
631 exit_dell_smbios_wmi();
632 exit_dell_smbios_smm();
633 mutex_lock(&smbios_mutex);
634 if (platform_device) {
635 if (da_tokens)
636 free_group(platform_device);
637 platform_device_unregister(platform_device);
638 platform_driver_unregister(&platform_driver);
639 }
640 kfree(da_tokens);
641 mutex_unlock(&smbios_mutex);
642 }
643
644 module_init(dell_smbios_init);
645 module_exit(dell_smbios_exit);
646
647 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
648 MODULE_AUTHOR("Gabriele Mazzotta <gabriele.mzt@gmail.com>");
649 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
650 MODULE_AUTHOR("Mario Limonciello <mario.limonciello@outlook.com>");
651 MODULE_DESCRIPTION("Common functions for kernel modules using Dell SMBIOS");
652 MODULE_LICENSE("GPL");
653