1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Functions corresponding to enumeration type attributes under
4 * BIOS Enumeration GUID for use with hp-bioscfg driver.
5 *
6 * Copyright (c) 2022 HP Development Company, L.P.
7 */
8
9 #include "bioscfg.h"
10
11 GET_INSTANCE_ID(enumeration);
12
current_value_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)13 static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
14 {
15 int instance_id = get_enumeration_instance_id(kobj);
16
17 if (instance_id < 0)
18 return -EIO;
19
20 return sysfs_emit(buf, "%s\n",
21 bioscfg_drv.enumeration_data[instance_id].current_value);
22 }
23
24 /**
25 * validate_enumeration_input() -
26 * Validate input of current_value against possible values
27 *
28 * @instance_id: The instance on which input is validated
29 * @buf: Input value
30 */
validate_enumeration_input(int instance_id,const char * buf)31 static int validate_enumeration_input(int instance_id, const char *buf)
32 {
33 int i;
34 int found = 0;
35 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
36
37 /* Is it a read only attribute */
38 if (enum_data->common.is_readonly)
39 return -EIO;
40
41 for (i = 0; i < enum_data->possible_values_size && !found; i++)
42 if (!strcmp(enum_data->possible_values[i], buf))
43 found = 1;
44
45 if (!found)
46 return -EINVAL;
47
48 return 0;
49 }
50
update_enumeration_value(int instance_id,char * attr_value)51 static void update_enumeration_value(int instance_id, char *attr_value)
52 {
53 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
54
55 strscpy(enum_data->current_value, attr_value);
56 }
57
58 ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, enumeration);
59 static struct kobj_attribute enumeration_display_name =
60 __ATTR_RO(display_name);
61
62 ATTRIBUTE_PROPERTY_STORE(current_value, enumeration);
63 static struct kobj_attribute enumeration_current_val =
64 __ATTR_RW(current_value);
65
66 ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration, SEMICOLON_SEP);
67 static struct kobj_attribute enumeration_poss_val =
68 __ATTR_RO(possible_values);
69
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)70 static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
71 char *buf)
72 {
73 return sysfs_emit(buf, "enumeration\n");
74 }
75
76 static struct kobj_attribute enumeration_type =
77 __ATTR_RO(type);
78
79 static struct attribute *enumeration_attrs[] = {
80 &common_display_langcode.attr,
81 &enumeration_display_name.attr,
82 &enumeration_current_val.attr,
83 &enumeration_poss_val.attr,
84 &enumeration_type.attr,
85 NULL
86 };
87
88 static const struct attribute_group enumeration_attr_group = {
89 .attrs = enumeration_attrs,
90 };
91
hp_alloc_enumeration_data(void)92 int hp_alloc_enumeration_data(void)
93 {
94 bioscfg_drv.enumeration_instances_count =
95 hp_get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
96
97 if (!bioscfg_drv.enumeration_instances_count)
98 return -EINVAL;
99 bioscfg_drv.enumeration_data = kvcalloc(bioscfg_drv.enumeration_instances_count,
100 sizeof(*bioscfg_drv.enumeration_data), GFP_KERNEL);
101
102 if (!bioscfg_drv.enumeration_data) {
103 bioscfg_drv.enumeration_instances_count = 0;
104 return -ENOMEM;
105 }
106 return 0;
107 }
108
109 /* Expected Values types associated with each element */
110 static const acpi_object_type expected_enum_types[] = {
111 [NAME] = ACPI_TYPE_STRING,
112 [VALUE] = ACPI_TYPE_STRING,
113 [PATH] = ACPI_TYPE_STRING,
114 [IS_READONLY] = ACPI_TYPE_INTEGER,
115 [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
116 [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
117 [SEQUENCE] = ACPI_TYPE_INTEGER,
118 [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
119 [PREREQUISITES] = ACPI_TYPE_STRING,
120 [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
121 [ENUM_CURRENT_VALUE] = ACPI_TYPE_STRING,
122 [ENUM_SIZE] = ACPI_TYPE_INTEGER,
123 [ENUM_POSSIBLE_VALUES] = ACPI_TYPE_STRING,
124 };
125
hp_populate_enumeration_elements_from_package(union acpi_object * enum_obj,int enum_obj_count,int instance_id)126 static int hp_populate_enumeration_elements_from_package(union acpi_object *enum_obj,
127 int enum_obj_count,
128 int instance_id)
129 {
130 char *str_value = NULL;
131 int value_len;
132 u32 size = 0;
133 u32 int_value = 0;
134 int elem = 0;
135 int reqs;
136 int pos_values;
137 int ret;
138 int eloc;
139 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
140
141 for (elem = 1, eloc = 1; elem < enum_obj_count; elem++, eloc++) {
142 /* ONLY look at the first ENUM_ELEM_CNT elements */
143 if (eloc == ENUM_ELEM_CNT)
144 goto exit_enumeration_package;
145
146 switch (enum_obj[elem].type) {
147 case ACPI_TYPE_STRING:
148 if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
149 ret = hp_convert_hexstr_to_str(enum_obj[elem].string.pointer,
150 enum_obj[elem].string.length,
151 &str_value, &value_len);
152 if (ret)
153 return -EINVAL;
154 }
155 break;
156 case ACPI_TYPE_INTEGER:
157 int_value = (u32)enum_obj[elem].integer.value;
158 break;
159 default:
160 pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
161 continue;
162 }
163
164 /* Check that both expected and read object type match */
165 if (expected_enum_types[eloc] != enum_obj[elem].type) {
166 pr_err("Error expected type %d for elem %d, but got type %d instead\n",
167 expected_enum_types[eloc], elem, enum_obj[elem].type);
168 kfree(str_value);
169 return -EIO;
170 }
171
172 /* Assign appropriate element value to corresponding field */
173 switch (eloc) {
174 case NAME:
175 case VALUE:
176 break;
177 case PATH:
178 strscpy(enum_data->common.path, str_value);
179 break;
180 case IS_READONLY:
181 enum_data->common.is_readonly = int_value;
182 break;
183 case DISPLAY_IN_UI:
184 enum_data->common.display_in_ui = int_value;
185 break;
186 case REQUIRES_PHYSICAL_PRESENCE:
187 enum_data->common.requires_physical_presence = int_value;
188 break;
189 case SEQUENCE:
190 enum_data->common.sequence = int_value;
191 break;
192 case PREREQUISITES_SIZE:
193 if (int_value > MAX_PREREQUISITES_SIZE) {
194 pr_warn("Prerequisites size value exceeded the maximum number of elements supported or data may be malformed\n");
195 int_value = MAX_PREREQUISITES_SIZE;
196 }
197 enum_data->common.prerequisites_size = int_value;
198
199 /*
200 * This step is needed to keep the expected
201 * element list pointing to the right obj[elem].type
202 * when the size is zero. PREREQUISITES
203 * object is omitted by BIOS when the size is
204 * zero.
205 */
206 if (int_value == 0)
207 eloc++;
208 break;
209
210 case PREREQUISITES:
211 size = min_t(u32, enum_data->common.prerequisites_size, MAX_PREREQUISITES_SIZE);
212 for (reqs = 0; reqs < size; reqs++) {
213 if (elem + reqs >= enum_obj_count) {
214 pr_err("Error enum-objects package is too small\n");
215 return -EINVAL;
216 }
217
218 ret = hp_convert_hexstr_to_str(enum_obj[elem + reqs].string.pointer,
219 enum_obj[elem + reqs].string.length,
220 &str_value, &value_len);
221
222 if (ret)
223 return -EINVAL;
224
225 strscpy(enum_data->common.prerequisites[reqs], str_value);
226
227 kfree(str_value);
228 str_value = NULL;
229 }
230 break;
231
232 case SECURITY_LEVEL:
233 enum_data->common.security_level = int_value;
234 break;
235
236 case ENUM_CURRENT_VALUE:
237 strscpy(enum_data->current_value, str_value);
238 break;
239 case ENUM_SIZE:
240 if (int_value > MAX_VALUES_SIZE) {
241 pr_warn("Possible number values size value exceeded the maximum number of elements supported or data may be malformed\n");
242 int_value = MAX_VALUES_SIZE;
243 }
244 enum_data->possible_values_size = int_value;
245
246 /*
247 * This step is needed to keep the expected
248 * element list pointing to the right obj[elem].type
249 * when the size is zero. POSSIBLE_VALUES
250 * object is omitted by BIOS when the size is zero.
251 */
252 if (int_value == 0)
253 eloc++;
254 break;
255
256 case ENUM_POSSIBLE_VALUES:
257 size = enum_data->possible_values_size;
258
259 for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
260 pos_values++) {
261 if (elem + pos_values >= enum_obj_count) {
262 pr_err("Error enum-objects package is too small\n");
263 return -EINVAL;
264 }
265
266 ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
267 enum_obj[elem + pos_values].string.length,
268 &str_value, &value_len);
269
270 if (ret)
271 return -EINVAL;
272
273 /*
274 * ignore strings when possible values size
275 * is greater than MAX_VALUES_SIZE
276 */
277 if (size < MAX_VALUES_SIZE)
278 strscpy(enum_data->possible_values[pos_values], str_value);
279
280 kfree(str_value);
281 str_value = NULL;
282 }
283 break;
284 default:
285 pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
286 break;
287 }
288
289 kfree(str_value);
290 str_value = NULL;
291 }
292
293 exit_enumeration_package:
294 kfree(str_value);
295 return 0;
296 }
297
298 /**
299 * hp_populate_enumeration_package_data() -
300 * Populate all properties of an instance under enumeration attribute
301 *
302 * @enum_obj: ACPI object with enumeration data
303 * @instance_id: The instance to enumerate
304 * @attr_name_kobj: The parent kernel object
305 */
hp_populate_enumeration_package_data(union acpi_object * enum_obj,int instance_id,struct kobject * attr_name_kobj)306 int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
307 int instance_id,
308 struct kobject *attr_name_kobj)
309 {
310 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
311
312 enum_data->attr_name_kobj = attr_name_kobj;
313
314 hp_populate_enumeration_elements_from_package(enum_obj,
315 enum_obj->package.count,
316 instance_id);
317 hp_update_attribute_permissions(enum_data->common.is_readonly,
318 &enumeration_current_val);
319 /*
320 * Several attributes have names such "MONDAY". Friendly
321 * user nane is generated to make the name more descriptive
322 */
323 hp_friendly_user_name_update(enum_data->common.path,
324 attr_name_kobj->name,
325 enum_data->common.display_name,
326 sizeof(enum_data->common.display_name));
327 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
328 }
329
hp_populate_enumeration_elements_from_buffer(u8 * buffer_ptr,u32 * buffer_size,int instance_id)330 static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
331 int instance_id)
332 {
333 int values;
334 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
335 int ret = 0;
336
337 /*
338 * Only data relevant to this driver and its functionality is
339 * read. BIOS defines the order in which each * element is
340 * read. Element 0 data is not relevant to this
341 * driver hence it is ignored. For clarity, all element names
342 * (DISPLAY_IN_UI) which defines the order in which is read
343 * and the name matches the variable where the data is stored.
344 *
345 * In earlier implementation, reported errors were ignored
346 * causing the data to remain uninitialized. It is not
347 * possible to determine if data read from BIOS is valid or
348 * not. It is for this reason functions may return a error
349 * without validating the data itself.
350 */
351
352 // VALUE:
353 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->current_value,
354 sizeof(enum_data->current_value));
355 if (ret < 0)
356 goto buffer_exit;
357
358 // COMMON:
359 ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &enum_data->common);
360 if (ret < 0)
361 goto buffer_exit;
362
363 // ENUM_CURRENT_VALUE:
364 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
365 enum_data->current_value,
366 sizeof(enum_data->current_value));
367 if (ret < 0)
368 goto buffer_exit;
369
370 // ENUM_SIZE:
371 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
372 &enum_data->possible_values_size);
373
374 if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
375 /* Report a message and limit possible values size to maximum value */
376 pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
377 enum_data->possible_values_size = MAX_VALUES_SIZE;
378 }
379
380 // ENUM_POSSIBLE_VALUES:
381 for (values = 0; values < enum_data->possible_values_size; values++) {
382 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
383 enum_data->possible_values[values],
384 sizeof(enum_data->possible_values[values]));
385 if (ret < 0)
386 break;
387 }
388
389 buffer_exit:
390 return ret;
391 }
392
393 /**
394 * hp_populate_enumeration_buffer_data() -
395 * Populate all properties of an instance under enumeration attribute
396 *
397 * @buffer_ptr: Buffer pointer
398 * @buffer_size: Buffer size
399 * @instance_id: The instance to enumerate
400 * @attr_name_kobj: The parent kernel object
401 */
hp_populate_enumeration_buffer_data(u8 * buffer_ptr,u32 * buffer_size,int instance_id,struct kobject * attr_name_kobj)402 int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
403 int instance_id,
404 struct kobject *attr_name_kobj)
405 {
406 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
407 int ret = 0;
408
409 enum_data->attr_name_kobj = attr_name_kobj;
410
411 /* Populate enumeration elements */
412 ret = hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
413 instance_id);
414 if (ret < 0)
415 return ret;
416
417 hp_update_attribute_permissions(enum_data->common.is_readonly,
418 &enumeration_current_val);
419 /*
420 * Several attributes have names such "MONDAY". A Friendlier
421 * user nane is generated to make the name more descriptive
422 */
423 hp_friendly_user_name_update(enum_data->common.path,
424 attr_name_kobj->name,
425 enum_data->common.display_name,
426 sizeof(enum_data->common.display_name));
427
428 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
429 }
430
431 /**
432 * hp_exit_enumeration_attributes() - Clear all attribute data
433 *
434 * Clears all data allocated for this group of attributes
435 */
hp_exit_enumeration_attributes(void)436 void hp_exit_enumeration_attributes(void)
437 {
438 int instance_id;
439
440 for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
441 instance_id++) {
442 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
443 struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
444
445 if (attr_name_kobj)
446 sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
447 }
448 bioscfg_drv.enumeration_instances_count = 0;
449
450 kvfree(bioscfg_drv.enumeration_data);
451 bioscfg_drv.enumeration_data = NULL;
452 }
453