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,
56 attr_value,
57 sizeof(enum_data->current_value));
58 }
59
60 ATTRIBUTE_S_COMMON_PROPERTY_SHOW(display_name, enumeration);
61 static struct kobj_attribute enumeration_display_name =
62 __ATTR_RO(display_name);
63
64 ATTRIBUTE_PROPERTY_STORE(current_value, enumeration);
65 static struct kobj_attribute enumeration_current_val =
66 __ATTR_RW(current_value);
67
68 ATTRIBUTE_VALUES_PROPERTY_SHOW(possible_values, enumeration, SEMICOLON_SEP);
69 static struct kobj_attribute enumeration_poss_val =
70 __ATTR_RO(possible_values);
71
type_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)72 static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr,
73 char *buf)
74 {
75 return sysfs_emit(buf, "enumeration\n");
76 }
77
78 static struct kobj_attribute enumeration_type =
79 __ATTR_RO(type);
80
81 static struct attribute *enumeration_attrs[] = {
82 &common_display_langcode.attr,
83 &enumeration_display_name.attr,
84 &enumeration_current_val.attr,
85 &enumeration_poss_val.attr,
86 &enumeration_type.attr,
87 NULL
88 };
89
90 static const struct attribute_group enumeration_attr_group = {
91 .attrs = enumeration_attrs,
92 };
93
hp_alloc_enumeration_data(void)94 int hp_alloc_enumeration_data(void)
95 {
96 bioscfg_drv.enumeration_instances_count =
97 hp_get_instance_count(HP_WMI_BIOS_ENUMERATION_GUID);
98
99 bioscfg_drv.enumeration_data = kcalloc(bioscfg_drv.enumeration_instances_count,
100 sizeof(*bioscfg_drv.enumeration_data), GFP_KERNEL);
101 if (!bioscfg_drv.enumeration_data) {
102 bioscfg_drv.enumeration_instances_count = 0;
103 return -ENOMEM;
104 }
105 return 0;
106 }
107
108 /* Expected Values types associated with each element */
109 static const acpi_object_type expected_enum_types[] = {
110 [NAME] = ACPI_TYPE_STRING,
111 [VALUE] = ACPI_TYPE_STRING,
112 [PATH] = ACPI_TYPE_STRING,
113 [IS_READONLY] = ACPI_TYPE_INTEGER,
114 [DISPLAY_IN_UI] = ACPI_TYPE_INTEGER,
115 [REQUIRES_PHYSICAL_PRESENCE] = ACPI_TYPE_INTEGER,
116 [SEQUENCE] = ACPI_TYPE_INTEGER,
117 [PREREQUISITES_SIZE] = ACPI_TYPE_INTEGER,
118 [PREREQUISITES] = ACPI_TYPE_STRING,
119 [SECURITY_LEVEL] = ACPI_TYPE_INTEGER,
120 [ENUM_CURRENT_VALUE] = ACPI_TYPE_STRING,
121 [ENUM_SIZE] = ACPI_TYPE_INTEGER,
122 [ENUM_POSSIBLE_VALUES] = ACPI_TYPE_STRING,
123 };
124
hp_populate_enumeration_elements_from_package(union acpi_object * enum_obj,int enum_obj_count,int instance_id)125 static int hp_populate_enumeration_elements_from_package(union acpi_object *enum_obj,
126 int enum_obj_count,
127 int instance_id)
128 {
129 char *str_value = NULL;
130 int value_len;
131 u32 size = 0;
132 u32 int_value = 0;
133 int elem = 0;
134 int reqs;
135 int pos_values;
136 int ret;
137 int eloc;
138 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
139
140 for (elem = 1, eloc = 1; elem < enum_obj_count; elem++, eloc++) {
141 /* ONLY look at the first ENUM_ELEM_CNT elements */
142 if (eloc == ENUM_ELEM_CNT)
143 goto exit_enumeration_package;
144
145 switch (enum_obj[elem].type) {
146 case ACPI_TYPE_STRING:
147 if (PREREQUISITES != elem && ENUM_POSSIBLE_VALUES != elem) {
148 ret = hp_convert_hexstr_to_str(enum_obj[elem].string.pointer,
149 enum_obj[elem].string.length,
150 &str_value, &value_len);
151 if (ret)
152 return -EINVAL;
153 }
154 break;
155 case ACPI_TYPE_INTEGER:
156 int_value = (u32)enum_obj[elem].integer.value;
157 break;
158 default:
159 pr_warn("Unsupported object type [%d]\n", enum_obj[elem].type);
160 continue;
161 }
162
163 /* Check that both expected and read object type match */
164 if (expected_enum_types[eloc] != enum_obj[elem].type) {
165 pr_err("Error expected type %d for elem %d, but got type %d instead\n",
166 expected_enum_types[eloc], elem, enum_obj[elem].type);
167 kfree(str_value);
168 return -EIO;
169 }
170
171 /* Assign appropriate element value to corresponding field */
172 switch (eloc) {
173 case NAME:
174 case VALUE:
175 break;
176 case PATH:
177 strscpy(enum_data->common.path, str_value,
178 sizeof(enum_data->common.path));
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 >= 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],
226 str_value,
227 sizeof(enum_data->common.prerequisites[reqs]));
228
229 kfree(str_value);
230 str_value = NULL;
231 }
232 break;
233
234 case SECURITY_LEVEL:
235 enum_data->common.security_level = int_value;
236 break;
237
238 case ENUM_CURRENT_VALUE:
239 strscpy(enum_data->current_value,
240 str_value, sizeof(enum_data->current_value));
241 break;
242 case ENUM_SIZE:
243 if (int_value > MAX_VALUES_SIZE) {
244 pr_warn("Possible number values size value exceeded the maximum number of elements supported or data may be malformed\n");
245 int_value = MAX_VALUES_SIZE;
246 }
247 enum_data->possible_values_size = int_value;
248
249 /*
250 * This step is needed to keep the expected
251 * element list pointing to the right obj[elem].type
252 * when the size is zero. POSSIBLE_VALUES
253 * object is omitted by BIOS when the size is zero.
254 */
255 if (int_value == 0)
256 eloc++;
257 break;
258
259 case ENUM_POSSIBLE_VALUES:
260 size = enum_data->possible_values_size;
261
262 for (pos_values = 0; pos_values < size && pos_values < MAX_VALUES_SIZE;
263 pos_values++) {
264 if (elem >= enum_obj_count) {
265 pr_err("Error enum-objects package is too small\n");
266 return -EINVAL;
267 }
268
269 ret = hp_convert_hexstr_to_str(enum_obj[elem + pos_values].string.pointer,
270 enum_obj[elem + pos_values].string.length,
271 &str_value, &value_len);
272
273 if (ret)
274 return -EINVAL;
275
276 /*
277 * ignore strings when possible values size
278 * is greater than MAX_VALUES_SIZE
279 */
280 if (size < MAX_VALUES_SIZE)
281 strscpy(enum_data->possible_values[pos_values],
282 str_value,
283 sizeof(enum_data->possible_values[pos_values]));
284
285 kfree(str_value);
286 str_value = NULL;
287 }
288 break;
289 default:
290 pr_warn("Invalid element: %d found in Enumeration attribute or data may be malformed\n", elem);
291 break;
292 }
293
294 kfree(str_value);
295 str_value = NULL;
296 }
297
298 exit_enumeration_package:
299 kfree(str_value);
300 return 0;
301 }
302
303 /**
304 * hp_populate_enumeration_package_data() -
305 * Populate all properties of an instance under enumeration attribute
306 *
307 * @enum_obj: ACPI object with enumeration data
308 * @instance_id: The instance to enumerate
309 * @attr_name_kobj: The parent kernel object
310 */
hp_populate_enumeration_package_data(union acpi_object * enum_obj,int instance_id,struct kobject * attr_name_kobj)311 int hp_populate_enumeration_package_data(union acpi_object *enum_obj,
312 int instance_id,
313 struct kobject *attr_name_kobj)
314 {
315 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
316
317 enum_data->attr_name_kobj = attr_name_kobj;
318
319 hp_populate_enumeration_elements_from_package(enum_obj,
320 enum_obj->package.count,
321 instance_id);
322 hp_update_attribute_permissions(enum_data->common.is_readonly,
323 &enumeration_current_val);
324 /*
325 * Several attributes have names such "MONDAY". Friendly
326 * user nane is generated to make the name more descriptive
327 */
328 hp_friendly_user_name_update(enum_data->common.path,
329 attr_name_kobj->name,
330 enum_data->common.display_name,
331 sizeof(enum_data->common.display_name));
332 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
333 }
334
hp_populate_enumeration_elements_from_buffer(u8 * buffer_ptr,u32 * buffer_size,int instance_id)335 static int hp_populate_enumeration_elements_from_buffer(u8 *buffer_ptr, u32 *buffer_size,
336 int instance_id)
337 {
338 int values;
339 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
340 int ret = 0;
341
342 /*
343 * Only data relevant to this driver and its functionality is
344 * read. BIOS defines the order in which each * element is
345 * read. Element 0 data is not relevant to this
346 * driver hence it is ignored. For clarity, all element names
347 * (DISPLAY_IN_UI) which defines the order in which is read
348 * and the name matches the variable where the data is stored.
349 *
350 * In earlier implementation, reported errors were ignored
351 * causing the data to remain uninitialized. It is not
352 * possible to determine if data read from BIOS is valid or
353 * not. It is for this reason functions may return a error
354 * without validating the data itself.
355 */
356
357 // VALUE:
358 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size, enum_data->current_value,
359 sizeof(enum_data->current_value));
360 if (ret < 0)
361 goto buffer_exit;
362
363 // COMMON:
364 ret = hp_get_common_data_from_buffer(&buffer_ptr, buffer_size, &enum_data->common);
365 if (ret < 0)
366 goto buffer_exit;
367
368 // ENUM_CURRENT_VALUE:
369 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
370 enum_data->current_value,
371 sizeof(enum_data->current_value));
372 if (ret < 0)
373 goto buffer_exit;
374
375 // ENUM_SIZE:
376 ret = hp_get_integer_from_buffer(&buffer_ptr, buffer_size,
377 &enum_data->possible_values_size);
378
379 if (enum_data->possible_values_size > MAX_VALUES_SIZE) {
380 /* Report a message and limit possible values size to maximum value */
381 pr_warn("Enum Possible size value exceeded the maximum number of elements supported or data may be malformed\n");
382 enum_data->possible_values_size = MAX_VALUES_SIZE;
383 }
384
385 // ENUM_POSSIBLE_VALUES:
386 for (values = 0; values < enum_data->possible_values_size; values++) {
387 ret = hp_get_string_from_buffer(&buffer_ptr, buffer_size,
388 enum_data->possible_values[values],
389 sizeof(enum_data->possible_values[values]));
390 if (ret < 0)
391 break;
392 }
393
394 buffer_exit:
395 return ret;
396 }
397
398 /**
399 * hp_populate_enumeration_buffer_data() -
400 * Populate all properties of an instance under enumeration attribute
401 *
402 * @buffer_ptr: Buffer pointer
403 * @buffer_size: Buffer size
404 * @instance_id: The instance to enumerate
405 * @attr_name_kobj: The parent kernel object
406 */
hp_populate_enumeration_buffer_data(u8 * buffer_ptr,u32 * buffer_size,int instance_id,struct kobject * attr_name_kobj)407 int hp_populate_enumeration_buffer_data(u8 *buffer_ptr, u32 *buffer_size,
408 int instance_id,
409 struct kobject *attr_name_kobj)
410 {
411 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
412 int ret = 0;
413
414 enum_data->attr_name_kobj = attr_name_kobj;
415
416 /* Populate enumeration elements */
417 ret = hp_populate_enumeration_elements_from_buffer(buffer_ptr, buffer_size,
418 instance_id);
419 if (ret < 0)
420 return ret;
421
422 hp_update_attribute_permissions(enum_data->common.is_readonly,
423 &enumeration_current_val);
424 /*
425 * Several attributes have names such "MONDAY". A Friendlier
426 * user nane is generated to make the name more descriptive
427 */
428 hp_friendly_user_name_update(enum_data->common.path,
429 attr_name_kobj->name,
430 enum_data->common.display_name,
431 sizeof(enum_data->common.display_name));
432
433 return sysfs_create_group(attr_name_kobj, &enumeration_attr_group);
434 }
435
436 /**
437 * hp_exit_enumeration_attributes() - Clear all attribute data
438 *
439 * Clears all data allocated for this group of attributes
440 */
hp_exit_enumeration_attributes(void)441 void hp_exit_enumeration_attributes(void)
442 {
443 int instance_id;
444
445 for (instance_id = 0; instance_id < bioscfg_drv.enumeration_instances_count;
446 instance_id++) {
447 struct enumeration_data *enum_data = &bioscfg_drv.enumeration_data[instance_id];
448 struct kobject *attr_name_kobj = enum_data->attr_name_kobj;
449
450 if (attr_name_kobj)
451 sysfs_remove_group(attr_name_kobj, &enumeration_attr_group);
452 }
453 bioscfg_drv.enumeration_instances_count = 0;
454
455 kfree(bioscfg_drv.enumeration_data);
456 bioscfg_drv.enumeration_data = NULL;
457 }
458