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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Think LMI BIOS configuration driver
  4 *
  5 * Copyright(C) 2019-2021 Lenovo
  6 *
  7 * Original code from Thinkpad-wmi project https://github.com/iksaif/thinkpad-wmi
  8 * Copyright(C) 2017 Corentin Chary <corentin.chary@gmail.com>
  9 * Distributed under the GPL-2.0 license
 10 */
 11
 12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13
 14#include <linux/acpi.h>
 15#include <linux/errno.h>
 16#include <linux/fs.h>
 17#include <linux/string.h>
 18#include <linux/types.h>
 19#include <linux/wmi.h>
 20#include "firmware_attributes_class.h"
 21#include "think-lmi.h"
 22
 23/*
 24 * Name:
 25 *  Lenovo_BiosSetting
 26 * Description:
 27 *  Get item name and settings for current LMI instance.
 28 * Type:
 29 *  Query
 30 * Returns:
 31 *  "Item,Value"
 32 * Example:
 33 *  "WakeOnLAN,Enable"
 34 */
 35#define LENOVO_BIOS_SETTING_GUID "51F5230E-9677-46CD-A1CF-C0B23EE34DB7"
 36
 37/*
 38 * Name:
 39 *  Lenovo_SetBiosSetting
 40 * Description:
 41 *  Change the BIOS setting to the desired value using the Lenovo_SetBiosSetting
 42 *  class. To save the settings, use the Lenovo_SaveBiosSetting class.
 43 *  BIOS settings and values are case sensitive.
 44 *  After making changes to the BIOS settings, you must reboot the computer
 45 *  before the changes will take effect.
 46 * Type:
 47 *  Method
 48 * Arguments:
 49 *  "Item,Value,Password,Encoding,KbdLang;"
 50 * Example:
 51 *  "WakeOnLAN,Disable,pa55w0rd,ascii,us;"
 52 */
 53#define LENOVO_SET_BIOS_SETTINGS_GUID "98479A64-33F5-4E33-A707-8E251EBBC3A1"
 54
 55/*
 56 * Name:
 57 *  Lenovo_SaveBiosSettings
 58 * Description:
 59 *  Save any pending changes in settings.
 60 * Type:
 61 *  Method
 62 * Arguments:
 63 *  "Password,Encoding,KbdLang;"
 64 * Example:
 65 * "pa55w0rd,ascii,us;"
 66 */
 67#define LENOVO_SAVE_BIOS_SETTINGS_GUID "6A4B54EF-A5ED-4D33-9455-B0D9B48DF4B3"
 68
 69/*
 70 * Name:
 71 *  Lenovo_BiosPasswordSettings
 72 * Description:
 73 *  Return BIOS Password settings
 74 * Type:
 75 *  Query
 76 * Returns:
 77 *  PasswordMode, PasswordState, MinLength, MaxLength,
 78 *  SupportedEncoding, SupportedKeyboard
 79 */
 80#define LENOVO_BIOS_PASSWORD_SETTINGS_GUID "8ADB159E-1E32-455C-BC93-308A7ED98246"
 81
 82/*
 83 * Name:
 84 *  Lenovo_SetBiosPassword
 85 * Description:
 86 *  Change a specific password.
 87 *  - BIOS settings cannot be changed at the same boot as power-on
 88 *    passwords (POP) and hard disk passwords (HDP). If you want to change
 89 *    BIOS settings and POP or HDP, you must reboot the system after changing
 90 *    one of them.
 91 *  - A password cannot be set using this method when one does not already
 92 *    exist. Passwords can only be updated or cleared.
 93 * Type:
 94 *  Method
 95 * Arguments:
 96 *  "PasswordType,CurrentPassword,NewPassword,Encoding,KbdLang;"
 97 * Example:
 98 *  "pop,pa55w0rd,newpa55w0rd,ascii,us;”
 99 */
100#define LENOVO_SET_BIOS_PASSWORD_GUID "2651D9FD-911C-4B69-B94E-D0DED5963BD7"
101
102/*
103 * Name:
104 *  Lenovo_GetBiosSelections
105 * Description:
106 *  Return a list of valid settings for a given item.
107 * Type:
108 *  Method
109 * Arguments:
110 *  "Item"
111 * Returns:
112 *  "Value1,Value2,Value3,..."
113 * Example:
114 *  -> "FlashOverLAN"
115 *  <- "Enabled,Disabled"
116 */
117#define LENOVO_GET_BIOS_SELECTIONS_GUID	"7364651A-132F-4FE7-ADAA-40C6C7EE2E3B"
118
119#define TLMI_POP_PWD (1 << 0)
120#define TLMI_PAP_PWD (1 << 1)
121#define to_tlmi_pwd_setting(kobj)  container_of(kobj, struct tlmi_pwd_setting, kobj)
122#define to_tlmi_attr_setting(kobj)  container_of(kobj, struct tlmi_attr_setting, kobj)
123
124static const struct tlmi_err_codes tlmi_errs[] = {
125	{"Success", 0},
126	{"Not Supported", -EOPNOTSUPP},
127	{"Invalid Parameter", -EINVAL},
128	{"Access Denied", -EACCES},
129	{"System Busy", -EBUSY},
130};
131
132static const char * const encoding_options[] = {
133	[TLMI_ENCODING_ASCII] = "ascii",
134	[TLMI_ENCODING_SCANCODE] = "scancode",
135};
136static struct think_lmi tlmi_priv;
137static struct class *fw_attr_class;
138
139/* ------ Utility functions ------------*/
140/* Convert BIOS WMI error string to suitable error code */
141static int tlmi_errstr_to_err(const char *errstr)
142{
143	int i;
144
145	for (i = 0; i < sizeof(tlmi_errs)/sizeof(struct tlmi_err_codes); i++) {
146		if (!strcmp(tlmi_errs[i].err_str, errstr))
147			return tlmi_errs[i].err_code;
148	}
149	return -EPERM;
150}
151
152/* Extract error string from WMI return buffer */
153static int tlmi_extract_error(const struct acpi_buffer *output)
154{
155	const union acpi_object *obj;
156
157	obj = output->pointer;
158	if (!obj)
159		return -ENOMEM;
160	if (obj->type != ACPI_TYPE_STRING || !obj->string.pointer)
161		return -EIO;
162
163	return tlmi_errstr_to_err(obj->string.pointer);
164}
165
166/* Utility function to execute WMI call to BIOS */
167static int tlmi_simple_call(const char *guid, const char *arg)
168{
169	const struct acpi_buffer input = { strlen(arg), (char *)arg };
170	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
171	acpi_status status;
172	int i, err;
173
174	/*
175	 * Duplicated call required to match BIOS workaround for behavior
176	 * seen when WMI accessed via scripting on other OS.
177	 */
178	for (i = 0; i < 2; i++) {
179		/* (re)initialize output buffer to default state */
180		output.length = ACPI_ALLOCATE_BUFFER;
181		output.pointer = NULL;
182
183		status = wmi_evaluate_method(guid, 0, 0, &input, &output);
184		if (ACPI_FAILURE(status)) {
185			kfree(output.pointer);
186			return -EIO;
187		}
188		err = tlmi_extract_error(&output);
189		kfree(output.pointer);
190		if (err)
191			return err;
192	}
193	return 0;
194}
195
196/* Extract output string from WMI return buffer */
197static int tlmi_extract_output_string(const struct acpi_buffer *output,
198				      char **string)
199{
200	const union acpi_object *obj;
201	char *s;
202
203	obj = output->pointer;
204	if (!obj)
205		return -ENOMEM;
206	if (obj->type != ACPI_TYPE_STRING || !obj->string.pointer)
207		return -EIO;
208
209	s = kstrdup(obj->string.pointer, GFP_KERNEL);
210	if (!s)
211		return -ENOMEM;
212	*string = s;
213	return 0;
214}
215
216/* ------ Core interface functions ------------*/
217
218/* Get password settings from BIOS */
219static int tlmi_get_pwd_settings(struct tlmi_pwdcfg *pwdcfg)
220{
221	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
222	const union acpi_object *obj;
223	acpi_status status;
224
225	if (!tlmi_priv.can_get_password_settings)
226		return -EOPNOTSUPP;
227
228	status = wmi_query_block(LENOVO_BIOS_PASSWORD_SETTINGS_GUID, 0,
229				 &output);
230	if (ACPI_FAILURE(status))
231		return -EIO;
232
233	obj = output.pointer;
234	if (!obj)
235		return -ENOMEM;
236	if (obj->type != ACPI_TYPE_BUFFER || !obj->buffer.pointer) {
237		kfree(obj);
238		return -EIO;
239	}
240	/*
241	 * The size of thinkpad_wmi_pcfg on ThinkStation is larger than ThinkPad.
242	 * To make the driver compatible on different brands, we permit it to get
243	 * the data in below case.
244	 */
245	if (obj->buffer.length < sizeof(struct tlmi_pwdcfg)) {
246		pr_warn("Unknown pwdcfg buffer length %d\n", obj->buffer.length);
247		kfree(obj);
248		return -EIO;
249	}
250	memcpy(pwdcfg, obj->buffer.pointer, sizeof(struct tlmi_pwdcfg));
251	kfree(obj);
252	return 0;
253}
254
255static int tlmi_save_bios_settings(const char *password)
256{
257	return tlmi_simple_call(LENOVO_SAVE_BIOS_SETTINGS_GUID,
258				password);
259}
260
261static int tlmi_setting(int item, char **value, const char *guid_string)
262{
263	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
264	acpi_status status;
265	int ret;
266
267	status = wmi_query_block(guid_string, item, &output);
268	if (ACPI_FAILURE(status)) {
269		kfree(output.pointer);
270		return -EIO;
271	}
272
273	ret = tlmi_extract_output_string(&output, value);
274	kfree(output.pointer);
275	return ret;
276}
277
278static int tlmi_get_bios_selections(const char *item, char **value)
279{
280	const struct acpi_buffer input = { strlen(item), (char *)item };
281	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
282	acpi_status status;
283	int ret;
284
285	status = wmi_evaluate_method(LENOVO_GET_BIOS_SELECTIONS_GUID,
286				     0, 0, &input, &output);
287
288	if (ACPI_FAILURE(status)) {
289		kfree(output.pointer);
290		return -EIO;
291	}
292
293	ret = tlmi_extract_output_string(&output, value);
294	kfree(output.pointer);
295	return ret;
296}
297
298/* ---- Authentication sysfs --------------------------------------------------------- */
299static ssize_t is_enabled_show(struct kobject *kobj, struct kobj_attribute *attr,
300					  char *buf)
301{
302	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
303
304	return sysfs_emit(buf, "%d\n", setting->valid);
305}
306
307static struct kobj_attribute auth_is_pass_set = __ATTR_RO(is_enabled);
308
309static ssize_t current_password_store(struct kobject *kobj,
310				      struct kobj_attribute *attr,
311				      const char *buf, size_t count)
312{
313	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
314	size_t pwdlen;
315	char *p;
316
317	pwdlen = strlen(buf);
318	/* pwdlen == 0 is allowed to clear the password */
319	if (pwdlen && ((pwdlen < setting->minlen) || (pwdlen > setting->maxlen)))
320		return -EINVAL;
321
322	strscpy(setting->password, buf, setting->maxlen);
323	/* Strip out CR if one is present, setting password won't work if it is present */
324	p = strchrnul(setting->password, '\n');
325	*p = '\0';
326	return count;
327}
328
329static struct kobj_attribute auth_current_password = __ATTR_WO(current_password);
330
331static ssize_t new_password_store(struct kobject *kobj,
332				  struct kobj_attribute *attr,
333				  const char *buf, size_t count)
334{
335	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
336	char *auth_str, *new_pwd, *p;
337	size_t pwdlen;
338	int ret;
339
340	if (!capable(CAP_SYS_ADMIN))
341		return -EPERM;
342
343	if (!tlmi_priv.can_set_bios_password)
344		return -EOPNOTSUPP;
345
346	new_pwd = kstrdup(buf, GFP_KERNEL);
347	if (!new_pwd)
348		return -ENOMEM;
349
350	/* Strip out CR if one is present, setting password won't work if it is present */
351	p = strchrnul(new_pwd, '\n');
352	*p = '\0';
353
354	pwdlen = strlen(new_pwd);
355	/* pwdlen == 0 is allowed to clear the password */
356	if (pwdlen && ((pwdlen < setting->minlen) || (pwdlen > setting->maxlen))) {
357		ret = -EINVAL;
358		goto out;
359	}
360
361	/* Format: 'PasswordType,CurrentPw,NewPw,Encoding,KbdLang;' */
362	auth_str = kasprintf(GFP_KERNEL, "%s,%s,%s,%s,%s;",
363		 setting->pwd_type, setting->password, new_pwd,
364		 encoding_options[setting->encoding], setting->kbdlang);
365	if (!auth_str) {
366		ret = -ENOMEM;
367		goto out;
368	}
369	ret = tlmi_simple_call(LENOVO_SET_BIOS_PASSWORD_GUID, auth_str);
370	kfree(auth_str);
371out:
372	kfree(new_pwd);
373	return ret ?: count;
374}
375
376static struct kobj_attribute auth_new_password = __ATTR_WO(new_password);
377
378static ssize_t min_password_length_show(struct kobject *kobj, struct kobj_attribute *attr,
379			 char *buf)
380{
381	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
382
383	return sysfs_emit(buf, "%d\n", setting->minlen);
384}
385
386static struct kobj_attribute auth_min_pass_length = __ATTR_RO(min_password_length);
387
388static ssize_t max_password_length_show(struct kobject *kobj, struct kobj_attribute *attr,
389			 char *buf)
390{
391	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
392
393	return sysfs_emit(buf, "%d\n", setting->maxlen);
394}
395static struct kobj_attribute auth_max_pass_length = __ATTR_RO(max_password_length);
396
397static ssize_t mechanism_show(struct kobject *kobj, struct kobj_attribute *attr,
398			 char *buf)
399{
400	return sysfs_emit(buf, "password\n");
401}
402static struct kobj_attribute auth_mechanism = __ATTR_RO(mechanism);
403
404static ssize_t encoding_show(struct kobject *kobj, struct kobj_attribute *attr,
405			 char *buf)
406{
407	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
408
409	return sysfs_emit(buf, "%s\n", encoding_options[setting->encoding]);
410}
411
412static ssize_t encoding_store(struct kobject *kobj,
413				  struct kobj_attribute *attr,
414				  const char *buf, size_t count)
415{
416	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
417	int i;
418
419	/* Scan for a matching profile */
420	i = sysfs_match_string(encoding_options, buf);
421	if (i < 0)
422		return -EINVAL;
423
424	setting->encoding = i;
425	return count;
426}
427
428static struct kobj_attribute auth_encoding = __ATTR_RW(encoding);
429
430static ssize_t kbdlang_show(struct kobject *kobj, struct kobj_attribute *attr,
431			 char *buf)
432{
433	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
434
435	return sysfs_emit(buf, "%s\n", setting->kbdlang);
436}
437
438static ssize_t kbdlang_store(struct kobject *kobj,
439				  struct kobj_attribute *attr,
440				  const char *buf, size_t count)
441{
442	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
443	int length;
444
445	/* Calculate length till '\n' or terminating 0 */
446	length = strchrnul(buf, '\n') - buf;
447	if (!length || length >= TLMI_LANG_MAXLEN)
448		return -EINVAL;
449
450	memcpy(setting->kbdlang, buf, length);
451	setting->kbdlang[length] = '\0';
452	return count;
453}
454
455static struct kobj_attribute auth_kbdlang = __ATTR_RW(kbdlang);
456
457static ssize_t role_show(struct kobject *kobj, struct kobj_attribute *attr,
458			 char *buf)
459{
460	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
461
462	return sysfs_emit(buf, "%s\n", setting->role);
463}
464static struct kobj_attribute auth_role = __ATTR_RO(role);
465
466static struct attribute *auth_attrs[] = {
467	&auth_is_pass_set.attr,
468	&auth_min_pass_length.attr,
469	&auth_max_pass_length.attr,
470	&auth_current_password.attr,
471	&auth_new_password.attr,
472	&auth_role.attr,
473	&auth_mechanism.attr,
474	&auth_encoding.attr,
475	&auth_kbdlang.attr,
476	NULL
477};
478
479static const struct attribute_group auth_attr_group = {
480	.attrs = auth_attrs,
481};
482
483/* ---- Attributes sysfs --------------------------------------------------------- */
484static ssize_t display_name_show(struct kobject *kobj, struct kobj_attribute *attr,
485		char *buf)
486{
487	struct tlmi_attr_setting *setting = to_tlmi_attr_setting(kobj);
488
489	return sysfs_emit(buf, "%s\n", setting->display_name);
490}
491
492static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
493{
494	struct tlmi_attr_setting *setting = to_tlmi_attr_setting(kobj);
495	char *item, *value;
496	int ret;
497
498	ret = tlmi_setting(setting->index, &item, LENOVO_BIOS_SETTING_GUID);
499	if (ret)
500		return ret;
501
502	/* validate and split from `item,value` -> `value` */
503	value = strpbrk(item, ",");
504	if (!value || value == item || !strlen(value + 1))
505		return -EINVAL;
506
507	ret = sysfs_emit(buf, "%s\n", value + 1);
508	kfree(item);
509	return ret;
510}
511
512static ssize_t possible_values_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
513{
514	struct tlmi_attr_setting *setting = to_tlmi_attr_setting(kobj);
515
516	if (!tlmi_priv.can_get_bios_selections)
517		return -EOPNOTSUPP;
518
519	return sysfs_emit(buf, "%s\n", setting->possible_values);
520}
521
522static ssize_t current_value_store(struct kobject *kobj,
523		struct kobj_attribute *attr,
524		const char *buf, size_t count)
525{
526	struct tlmi_attr_setting *setting = to_tlmi_attr_setting(kobj);
527	char *set_str = NULL, *new_setting = NULL;
528	char *auth_str = NULL;
529	char *p;
530	int ret;
531
532	if (!tlmi_priv.can_set_bios_settings)
533		return -EOPNOTSUPP;
534
535	new_setting = kstrdup(buf, GFP_KERNEL);
536	if (!new_setting)
537		return -ENOMEM;
538
539	/* Strip out CR if one is present */
540	p = strchrnul(new_setting, '\n');
541	*p = '\0';
542
543	if (tlmi_priv.pwd_admin->valid && tlmi_priv.pwd_admin->password[0]) {
544		auth_str = kasprintf(GFP_KERNEL, "%s,%s,%s;",
545				tlmi_priv.pwd_admin->password,
546				encoding_options[tlmi_priv.pwd_admin->encoding],
547				tlmi_priv.pwd_admin->kbdlang);
548		if (!auth_str) {
549			ret = -ENOMEM;
550			goto out;
551		}
552	}
553
554	if (auth_str)
555		set_str = kasprintf(GFP_KERNEL, "%s,%s,%s", setting->display_name,
556				new_setting, auth_str);
557	else
558		set_str = kasprintf(GFP_KERNEL, "%s,%s;", setting->display_name,
559				new_setting);
560	if (!set_str) {
561		ret = -ENOMEM;
562		goto out;
563	}
564
565	ret = tlmi_simple_call(LENOVO_SET_BIOS_SETTINGS_GUID, set_str);
566	if (ret)
567		goto out;
568
569	if (auth_str)
570		ret = tlmi_save_bios_settings(auth_str);
571	else
572		ret = tlmi_save_bios_settings("");
573
574	if (!ret && !tlmi_priv.pending_changes) {
575		tlmi_priv.pending_changes = true;
576		/* let userland know it may need to check reboot pending again */
577		kobject_uevent(&tlmi_priv.class_dev->kobj, KOBJ_CHANGE);
578	}
579out:
580	kfree(auth_str);
581	kfree(set_str);
582	kfree(new_setting);
583	return ret ?: count;
584}
585
586static struct kobj_attribute attr_displ_name = __ATTR_RO(display_name);
587
588static struct kobj_attribute attr_possible_values = __ATTR_RO(possible_values);
589
590static struct kobj_attribute attr_current_val = __ATTR_RW_MODE(current_value, 0600);
591
592static struct attribute *tlmi_attrs[] = {
593	&attr_displ_name.attr,
594	&attr_current_val.attr,
595	&attr_possible_values.attr,
596	NULL
597};
598
599static const struct attribute_group tlmi_attr_group = {
600	.attrs = tlmi_attrs,
601};
602
603static ssize_t tlmi_attr_show(struct kobject *kobj, struct attribute *attr,
604				    char *buf)
605{
606	struct kobj_attribute *kattr;
607
608	kattr = container_of(attr, struct kobj_attribute, attr);
609	if (kattr->show)
610		return kattr->show(kobj, kattr, buf);
611	return -EIO;
612}
613
614static ssize_t tlmi_attr_store(struct kobject *kobj, struct attribute *attr,
615				     const char *buf, size_t count)
616{
617	struct kobj_attribute *kattr;
618
619	kattr = container_of(attr, struct kobj_attribute, attr);
620	if (kattr->store)
621		return kattr->store(kobj, kattr, buf, count);
622	return -EIO;
623}
624
625static const struct sysfs_ops tlmi_kobj_sysfs_ops = {
626	.show	= tlmi_attr_show,
627	.store	= tlmi_attr_store,
628};
629
630static void tlmi_attr_setting_release(struct kobject *kobj)
631{
632	struct tlmi_attr_setting *setting = to_tlmi_attr_setting(kobj);
633
634	kfree(setting->possible_values);
635	kfree(setting);
636}
637
638static void tlmi_pwd_setting_release(struct kobject *kobj)
639{
640	struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj);
641
642	kfree(setting);
643}
644
645static struct kobj_type tlmi_attr_setting_ktype = {
646	.release        = &tlmi_attr_setting_release,
647	.sysfs_ops	= &tlmi_kobj_sysfs_ops,
648};
649
650static struct kobj_type tlmi_pwd_setting_ktype = {
651	.release        = &tlmi_pwd_setting_release,
652	.sysfs_ops	= &tlmi_kobj_sysfs_ops,
653};
654
655static ssize_t pending_reboot_show(struct kobject *kobj, struct kobj_attribute *attr,
656				   char *buf)
657{
658	return sprintf(buf, "%d\n", tlmi_priv.pending_changes);
659}
660
661static struct kobj_attribute pending_reboot = __ATTR_RO(pending_reboot);
662
663/* ---- Initialisation --------------------------------------------------------- */
664static void tlmi_release_attr(void)
665{
666	int i;
667
668	/* Attribute structures */
669	for (i = 0; i < TLMI_SETTINGS_COUNT; i++) {
670		if (tlmi_priv.setting[i]) {
671			sysfs_remove_group(&tlmi_priv.setting[i]->kobj, &tlmi_attr_group);
672			kobject_put(&tlmi_priv.setting[i]->kobj);
673		}
674	}
675	sysfs_remove_file(&tlmi_priv.attribute_kset->kobj, &pending_reboot.attr);
676	kset_unregister(tlmi_priv.attribute_kset);
677
678	/* Authentication structures */
679	sysfs_remove_group(&tlmi_priv.pwd_admin->kobj, &auth_attr_group);
680	kobject_put(&tlmi_priv.pwd_admin->kobj);
681	sysfs_remove_group(&tlmi_priv.pwd_power->kobj, &auth_attr_group);
682	kobject_put(&tlmi_priv.pwd_power->kobj);
683	kset_unregister(tlmi_priv.authentication_kset);
684}
685
686static int tlmi_sysfs_init(void)
687{
688	int i, ret;
689
690	ret = fw_attributes_class_get(&fw_attr_class);
691	if (ret)
692		return ret;
693
694	tlmi_priv.class_dev = device_create(fw_attr_class, NULL, MKDEV(0, 0),
695			NULL, "%s", "thinklmi");
696	if (IS_ERR(tlmi_priv.class_dev)) {
697		ret = PTR_ERR(tlmi_priv.class_dev);
698		goto fail_class_created;
699	}
700
701	tlmi_priv.attribute_kset = kset_create_and_add("attributes", NULL,
702			&tlmi_priv.class_dev->kobj);
703	if (!tlmi_priv.attribute_kset) {
704		ret = -ENOMEM;
705		goto fail_device_created;
706	}
707
708	for (i = 0; i < TLMI_SETTINGS_COUNT; i++) {
709		/* Check if index is a valid setting - skip if it isn't */
710		if (!tlmi_priv.setting[i])
711			continue;
712
713		/* check for duplicate or reserved values */
714		if (kset_find_obj(tlmi_priv.attribute_kset, tlmi_priv.setting[i]->display_name) ||
715		    !strcmp(tlmi_priv.setting[i]->display_name, "Reserved")) {
716			pr_debug("duplicate or reserved attribute name found - %s\n",
717				tlmi_priv.setting[i]->display_name);
718			kfree(tlmi_priv.setting[i]->possible_values);
719			kfree(tlmi_priv.setting[i]);
720			tlmi_priv.setting[i] = NULL;
721			continue;
722		}
723
724		/* Build attribute */
725		tlmi_priv.setting[i]->kobj.kset = tlmi_priv.attribute_kset;
726		ret = kobject_add(&tlmi_priv.setting[i]->kobj, NULL,
727				  "%s", tlmi_priv.setting[i]->display_name);
728		if (ret)
729			goto fail_create_attr;
730
731		ret = sysfs_create_group(&tlmi_priv.setting[i]->kobj, &tlmi_attr_group);
732		if (ret)
733			goto fail_create_attr;
734	}
735
736	ret = sysfs_create_file(&tlmi_priv.attribute_kset->kobj, &pending_reboot.attr);
737	if (ret)
738		goto fail_create_attr;
739
740	/* Create authentication entries */
741	tlmi_priv.authentication_kset = kset_create_and_add("authentication", NULL,
742								&tlmi_priv.class_dev->kobj);
743	if (!tlmi_priv.authentication_kset) {
744		ret = -ENOMEM;
745		goto fail_create_attr;
746	}
747	tlmi_priv.pwd_admin->kobj.kset = tlmi_priv.authentication_kset;
748	ret = kobject_add(&tlmi_priv.pwd_admin->kobj, NULL, "%s", "Admin");
749	if (ret)
750		goto fail_create_attr;
751
752	ret = sysfs_create_group(&tlmi_priv.pwd_admin->kobj, &auth_attr_group);
753	if (ret)
754		goto fail_create_attr;
755
756	tlmi_priv.pwd_power->kobj.kset = tlmi_priv.authentication_kset;
757	ret = kobject_add(&tlmi_priv.pwd_power->kobj, NULL, "%s", "System");
758	if (ret)
759		goto fail_create_attr;
760
761	ret = sysfs_create_group(&tlmi_priv.pwd_power->kobj, &auth_attr_group);
762	if (ret)
763		goto fail_create_attr;
764
765	return ret;
766
767fail_create_attr:
768	tlmi_release_attr();
769fail_device_created:
770	device_destroy(fw_attr_class, MKDEV(0, 0));
771fail_class_created:
772	fw_attributes_class_put();
773	return ret;
774}
775
776/* ---- Base Driver -------------------------------------------------------- */
777static int tlmi_analyze(void)
778{
779	struct tlmi_pwdcfg pwdcfg;
780	acpi_status status;
781	int i, ret;
782
783	if (wmi_has_guid(LENOVO_SET_BIOS_SETTINGS_GUID) &&
784	    wmi_has_guid(LENOVO_SAVE_BIOS_SETTINGS_GUID))
785		tlmi_priv.can_set_bios_settings = true;
786
787	if (wmi_has_guid(LENOVO_GET_BIOS_SELECTIONS_GUID))
788		tlmi_priv.can_get_bios_selections = true;
789
790	if (wmi_has_guid(LENOVO_SET_BIOS_PASSWORD_GUID))
791		tlmi_priv.can_set_bios_password = true;
792
793	if (wmi_has_guid(LENOVO_BIOS_PASSWORD_SETTINGS_GUID))
794		tlmi_priv.can_get_password_settings = true;
795
796	/*
797	 * Try to find the number of valid settings of this machine
798	 * and use it to create sysfs attributes.
799	 */
800	for (i = 0; i < TLMI_SETTINGS_COUNT; ++i) {
801		struct tlmi_attr_setting *setting;
802		char *item = NULL;
803		char *p;
804
805		tlmi_priv.setting[i] = NULL;
806		status = tlmi_setting(i, &item, LENOVO_BIOS_SETTING_GUID);
807		if (ACPI_FAILURE(status))
808			break;
809		if (!item)
810			break;
811		if (!*item)
812			continue;
813
814		/* It is not allowed to have '/' for file name. Convert it into '\'. */
815		strreplace(item, '/', '\\');
816
817		/* Remove the value part */
818		p = strchrnul(item, ',');
819		*p = '\0';
820
821		/* Create a setting entry */
822		setting = kzalloc(sizeof(*setting), GFP_KERNEL);
823		if (!setting) {
824			ret = -ENOMEM;
825			goto fail_clear_attr;
826		}
827		setting->index = i;
828		strscpy(setting->display_name, item, TLMI_SETTINGS_MAXLEN);
829		/* If BIOS selections supported, load those */
830		if (tlmi_priv.can_get_bios_selections) {
831			ret = tlmi_get_bios_selections(setting->display_name,
832					&setting->possible_values);
833			if (ret || !setting->possible_values)
834				pr_info("Error retrieving possible values for %d : %s\n",
835						i, setting->display_name);
836		}
837		kobject_init(&setting->kobj, &tlmi_attr_setting_ktype);
838		tlmi_priv.setting[i] = setting;
839		tlmi_priv.settings_count++;
840		kfree(item);
841	}
842
843	/* Create password setting structure */
844	ret = tlmi_get_pwd_settings(&pwdcfg);
845	if (ret)
846		goto fail_clear_attr;
847
848	tlmi_priv.pwd_admin = kzalloc(sizeof(struct tlmi_pwd_setting), GFP_KERNEL);
849	if (!tlmi_priv.pwd_admin) {
850		ret = -ENOMEM;
851		goto fail_clear_attr;
852	}
853	strscpy(tlmi_priv.pwd_admin->kbdlang, "us", TLMI_LANG_MAXLEN);
854	tlmi_priv.pwd_admin->encoding = TLMI_ENCODING_ASCII;
855	tlmi_priv.pwd_admin->pwd_type = "pap";
856	tlmi_priv.pwd_admin->role = "bios-admin";
857	tlmi_priv.pwd_admin->minlen = pwdcfg.min_length;
858	if (WARN_ON(pwdcfg.max_length >= TLMI_PWD_BUFSIZE))
859		pwdcfg.max_length = TLMI_PWD_BUFSIZE - 1;
860	tlmi_priv.pwd_admin->maxlen = pwdcfg.max_length;
861	if (pwdcfg.password_state & TLMI_PAP_PWD)
862		tlmi_priv.pwd_admin->valid = true;
863
864	kobject_init(&tlmi_priv.pwd_admin->kobj, &tlmi_pwd_setting_ktype);
865
866	tlmi_priv.pwd_power = kzalloc(sizeof(struct tlmi_pwd_setting), GFP_KERNEL);
867	if (!tlmi_priv.pwd_power) {
868		ret = -ENOMEM;
869		goto fail_free_pwd_admin;
870	}
871	strscpy(tlmi_priv.pwd_power->kbdlang, "us", TLMI_LANG_MAXLEN);
872	tlmi_priv.pwd_power->encoding = TLMI_ENCODING_ASCII;
873	tlmi_priv.pwd_power->pwd_type = "pop";
874	tlmi_priv.pwd_power->role = "power-on";
875	tlmi_priv.pwd_power->minlen = pwdcfg.min_length;
876	tlmi_priv.pwd_power->maxlen = pwdcfg.max_length;
877
878	if (pwdcfg.password_state & TLMI_POP_PWD)
879		tlmi_priv.pwd_power->valid = true;
880
881	kobject_init(&tlmi_priv.pwd_power->kobj, &tlmi_pwd_setting_ktype);
882
883	return 0;
884
885fail_free_pwd_admin:
886	kfree(tlmi_priv.pwd_admin);
887fail_clear_attr:
888	for (i = 0; i < TLMI_SETTINGS_COUNT; ++i) {
889		if (tlmi_priv.setting[i]) {
890			kfree(tlmi_priv.setting[i]->possible_values);
891			kfree(tlmi_priv.setting[i]);
892		}
893	}
894	return ret;
895}
896
897static void tlmi_remove(struct wmi_device *wdev)
898{
899	tlmi_release_attr();
900	device_destroy(fw_attr_class, MKDEV(0, 0));
901	fw_attributes_class_put();
902}
903
904static int tlmi_probe(struct wmi_device *wdev, const void *context)
905{
906	tlmi_analyze();
907	return tlmi_sysfs_init();
908}
909
910static const struct wmi_device_id tlmi_id_table[] = {
911	{ .guid_string = LENOVO_BIOS_SETTING_GUID },
912	{ }
913};
914MODULE_DEVICE_TABLE(wmi, tlmi_id_table);
915
916static struct wmi_driver tlmi_driver = {
917	.driver = {
918		.name = "think-lmi",
919	},
920	.id_table = tlmi_id_table,
921	.probe = tlmi_probe,
922	.remove = tlmi_remove,
923};
924
925MODULE_AUTHOR("Sugumaran L <slacshiminar@lenovo.com>");
926MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
927MODULE_AUTHOR("Corentin Chary <corentin.chary@gmail.com>");
928MODULE_DESCRIPTION("ThinkLMI Driver");
929MODULE_LICENSE("GPL");
930
931module_wmi_driver(tlmi_driver);