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 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 */ 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 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 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 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 }; 124 125 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 */ 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 } 334 335 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 */ 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 */ 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