1 /******************************************************************************* 2 * 3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2013, Intel Corp. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer, 16 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include <acpi/acpi.h> 45 #include "accommon.h" 46 #include "amlcode.h" 47 #include "acnamesp.h" 48 #include "acdispat.h" 49 50 #define _COMPONENT ACPI_NAMESPACE 51 ACPI_MODULE_NAME("nsaccess") 52 53 /******************************************************************************* 54 * 55 * FUNCTION: acpi_ns_root_initialize 56 * 57 * PARAMETERS: None 58 * 59 * RETURN: Status 60 * 61 * DESCRIPTION: Allocate and initialize the default root named objects 62 * 63 * MUTEX: Locks namespace for entire execution 64 * 65 ******************************************************************************/ 66 acpi_status acpi_ns_root_initialize(void) 67 { 68 acpi_status status; 69 const struct acpi_predefined_names *init_val = NULL; 70 struct acpi_namespace_node *new_node; 71 union acpi_operand_object *obj_desc; 72 acpi_string val = NULL; 73 74 ACPI_FUNCTION_TRACE(ns_root_initialize); 75 76 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE); 77 if (ACPI_FAILURE(status)) { 78 return_ACPI_STATUS(status); 79 } 80 81 /* 82 * The global root ptr is initially NULL, so a non-NULL value indicates 83 * that acpi_ns_root_initialize() has already been called; just return. 84 */ 85 if (acpi_gbl_root_node) { 86 status = AE_OK; 87 goto unlock_and_exit; 88 } 89 90 /* 91 * Tell the rest of the subsystem that the root is initialized 92 * (This is OK because the namespace is locked) 93 */ 94 acpi_gbl_root_node = &acpi_gbl_root_node_struct; 95 96 /* Enter the pre-defined names in the name table */ 97 98 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 99 "Entering predefined entries into namespace\n")); 100 101 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) { 102 103 /* _OSI is optional for now, will be permanent later */ 104 105 if (!ACPI_STRCMP(init_val->name, "_OSI") 106 && !acpi_gbl_create_osi_method) { 107 continue; 108 } 109 110 status = acpi_ns_lookup(NULL, init_val->name, init_val->type, 111 ACPI_IMODE_LOAD_PASS2, 112 ACPI_NS_NO_UPSEARCH, NULL, &new_node); 113 if (ACPI_FAILURE(status)) { 114 ACPI_EXCEPTION((AE_INFO, status, 115 "Could not create predefined name %s", 116 init_val->name)); 117 continue; 118 } 119 120 /* 121 * Name entered successfully. If entry in pre_defined_names[] specifies 122 * an initial value, create the initial value. 123 */ 124 if (init_val->val) { 125 status = acpi_os_predefined_override(init_val, &val); 126 if (ACPI_FAILURE(status)) { 127 ACPI_ERROR((AE_INFO, 128 "Could not override predefined %s", 129 init_val->name)); 130 } 131 132 if (!val) { 133 val = init_val->val; 134 } 135 136 /* 137 * Entry requests an initial value, allocate a 138 * descriptor for it. 139 */ 140 obj_desc = 141 acpi_ut_create_internal_object(init_val->type); 142 if (!obj_desc) { 143 status = AE_NO_MEMORY; 144 goto unlock_and_exit; 145 } 146 147 /* 148 * Convert value string from table entry to 149 * internal representation. Only types actually 150 * used for initial values are implemented here. 151 */ 152 switch (init_val->type) { 153 case ACPI_TYPE_METHOD: 154 155 obj_desc->method.param_count = 156 (u8) ACPI_TO_INTEGER(val); 157 obj_desc->common.flags |= AOPOBJ_DATA_VALID; 158 159 #if defined (ACPI_ASL_COMPILER) 160 161 /* Save the parameter count for the iASL compiler */ 162 163 new_node->value = obj_desc->method.param_count; 164 #else 165 /* Mark this as a very SPECIAL method */ 166 167 obj_desc->method.info_flags = 168 ACPI_METHOD_INTERNAL_ONLY; 169 obj_desc->method.dispatch.implementation = 170 acpi_ut_osi_implementation; 171 #endif 172 break; 173 174 case ACPI_TYPE_INTEGER: 175 176 obj_desc->integer.value = ACPI_TO_INTEGER(val); 177 break; 178 179 case ACPI_TYPE_STRING: 180 181 /* Build an object around the static string */ 182 183 obj_desc->string.length = (u32)ACPI_STRLEN(val); 184 obj_desc->string.pointer = val; 185 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER; 186 break; 187 188 case ACPI_TYPE_MUTEX: 189 190 obj_desc->mutex.node = new_node; 191 obj_desc->mutex.sync_level = 192 (u8) (ACPI_TO_INTEGER(val) - 1); 193 194 /* Create a mutex */ 195 196 status = 197 acpi_os_create_mutex(&obj_desc->mutex. 198 os_mutex); 199 if (ACPI_FAILURE(status)) { 200 acpi_ut_remove_reference(obj_desc); 201 goto unlock_and_exit; 202 } 203 204 /* Special case for ACPI Global Lock */ 205 206 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) { 207 acpi_gbl_global_lock_mutex = obj_desc; 208 209 /* Create additional counting semaphore for global lock */ 210 211 status = 212 acpi_os_create_semaphore(1, 0, 213 &acpi_gbl_global_lock_semaphore); 214 if (ACPI_FAILURE(status)) { 215 acpi_ut_remove_reference 216 (obj_desc); 217 goto unlock_and_exit; 218 } 219 } 220 break; 221 222 default: 223 224 ACPI_ERROR((AE_INFO, 225 "Unsupported initial type value 0x%X", 226 init_val->type)); 227 acpi_ut_remove_reference(obj_desc); 228 obj_desc = NULL; 229 continue; 230 } 231 232 /* Store pointer to value descriptor in the Node */ 233 234 status = acpi_ns_attach_object(new_node, obj_desc, 235 obj_desc->common.type); 236 237 /* Remove local reference to the object */ 238 239 acpi_ut_remove_reference(obj_desc); 240 } 241 } 242 243 unlock_and_exit: 244 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); 245 246 /* Save a handle to "_GPE", it is always present */ 247 248 if (ACPI_SUCCESS(status)) { 249 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH, 250 &acpi_gbl_fadt_gpe_device); 251 } 252 253 return_ACPI_STATUS(status); 254 } 255 256 /******************************************************************************* 257 * 258 * FUNCTION: acpi_ns_lookup 259 * 260 * PARAMETERS: scope_info - Current scope info block 261 * pathname - Search pathname, in internal format 262 * (as represented in the AML stream) 263 * type - Type associated with name 264 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found 265 * flags - Flags describing the search restrictions 266 * walk_state - Current state of the walk 267 * return_node - Where the Node is placed (if found 268 * or created successfully) 269 * 270 * RETURN: Status 271 * 272 * DESCRIPTION: Find or enter the passed name in the name space. 273 * Log an error if name not found in Exec mode. 274 * 275 * MUTEX: Assumes namespace is locked. 276 * 277 ******************************************************************************/ 278 279 acpi_status 280 acpi_ns_lookup(union acpi_generic_state *scope_info, 281 char *pathname, 282 acpi_object_type type, 283 acpi_interpreter_mode interpreter_mode, 284 u32 flags, 285 struct acpi_walk_state *walk_state, 286 struct acpi_namespace_node **return_node) 287 { 288 acpi_status status; 289 char *path = pathname; 290 struct acpi_namespace_node *prefix_node; 291 struct acpi_namespace_node *current_node = NULL; 292 struct acpi_namespace_node *this_node = NULL; 293 u32 num_segments; 294 u32 num_carats; 295 acpi_name simple_name; 296 acpi_object_type type_to_check_for; 297 acpi_object_type this_search_type; 298 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT; 299 u32 local_flags; 300 301 ACPI_FUNCTION_TRACE(ns_lookup); 302 303 if (!return_node) { 304 return_ACPI_STATUS(AE_BAD_PARAMETER); 305 } 306 307 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT); 308 *return_node = ACPI_ENTRY_NOT_FOUND; 309 acpi_gbl_ns_lookup_count++; 310 311 if (!acpi_gbl_root_node) { 312 return_ACPI_STATUS(AE_NO_NAMESPACE); 313 } 314 315 /* Get the prefix scope. A null scope means use the root scope */ 316 317 if ((!scope_info) || (!scope_info->scope.node)) { 318 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 319 "Null scope prefix, using root node (%p)\n", 320 acpi_gbl_root_node)); 321 322 prefix_node = acpi_gbl_root_node; 323 } else { 324 prefix_node = scope_info->scope.node; 325 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) != 326 ACPI_DESC_TYPE_NAMED) { 327 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]", 328 prefix_node, 329 acpi_ut_get_descriptor_name(prefix_node))); 330 return_ACPI_STATUS(AE_AML_INTERNAL); 331 } 332 333 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) { 334 /* 335 * This node might not be a actual "scope" node (such as a 336 * Device/Method, etc.) It could be a Package or other object 337 * node. Backup up the tree to find the containing scope node. 338 */ 339 while (!acpi_ns_opens_scope(prefix_node->type) && 340 prefix_node->type != ACPI_TYPE_ANY) { 341 prefix_node = prefix_node->parent; 342 } 343 } 344 } 345 346 /* Save type. TBD: may be no longer necessary */ 347 348 type_to_check_for = type; 349 350 /* 351 * Begin examination of the actual pathname 352 */ 353 if (!pathname) { 354 355 /* A Null name_path is allowed and refers to the root */ 356 357 num_segments = 0; 358 this_node = acpi_gbl_root_node; 359 path = ""; 360 361 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 362 "Null Pathname (Zero segments), Flags=%X\n", 363 flags)); 364 } else { 365 /* 366 * Name pointer is valid (and must be in internal name format) 367 * 368 * Check for scope prefixes: 369 * 370 * As represented in the AML stream, a namepath consists of an 371 * optional scope prefix followed by a name segment part. 372 * 373 * If present, the scope prefix is either a Root Prefix (in 374 * which case the name is fully qualified), or one or more 375 * Parent Prefixes (in which case the name's scope is relative 376 * to the current scope). 377 */ 378 if (*path == (u8) AML_ROOT_PREFIX) { 379 380 /* Pathname is fully qualified, start from the root */ 381 382 this_node = acpi_gbl_root_node; 383 search_parent_flag = ACPI_NS_NO_UPSEARCH; 384 385 /* Point to name segment part */ 386 387 path++; 388 389 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 390 "Path is absolute from root [%p]\n", 391 this_node)); 392 } else { 393 /* Pathname is relative to current scope, start there */ 394 395 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 396 "Searching relative to prefix scope [%4.4s] (%p)\n", 397 acpi_ut_get_node_name(prefix_node), 398 prefix_node)); 399 400 /* 401 * Handle multiple Parent Prefixes (carat) by just getting 402 * the parent node for each prefix instance. 403 */ 404 this_node = prefix_node; 405 num_carats = 0; 406 while (*path == (u8) AML_PARENT_PREFIX) { 407 408 /* Name is fully qualified, no search rules apply */ 409 410 search_parent_flag = ACPI_NS_NO_UPSEARCH; 411 412 /* 413 * Point past this prefix to the name segment 414 * part or the next Parent Prefix 415 */ 416 path++; 417 418 /* Backup to the parent node */ 419 420 num_carats++; 421 this_node = this_node->parent; 422 if (!this_node) { 423 424 /* Current scope has no parent scope */ 425 426 ACPI_ERROR((AE_INFO, 427 "%s: Path has too many parent prefixes (^) " 428 "- reached beyond root node", 429 pathname)); 430 return_ACPI_STATUS(AE_NOT_FOUND); 431 } 432 } 433 434 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) { 435 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 436 "Search scope is [%4.4s], path has %u carat(s)\n", 437 acpi_ut_get_node_name 438 (this_node), num_carats)); 439 } 440 } 441 442 /* 443 * Determine the number of ACPI name segments in this pathname. 444 * 445 * The segment part consists of either: 446 * - A Null name segment (0) 447 * - A dual_name_prefix followed by two 4-byte name segments 448 * - A multi_name_prefix followed by a byte indicating the 449 * number of segments and the segments themselves. 450 * - A single 4-byte name segment 451 * 452 * Examine the name prefix opcode, if any, to determine the number of 453 * segments. 454 */ 455 switch (*path) { 456 case 0: 457 /* 458 * Null name after a root or parent prefixes. We already 459 * have the correct target node and there are no name segments. 460 */ 461 num_segments = 0; 462 type = this_node->type; 463 464 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 465 "Prefix-only Pathname (Zero name segments), Flags=%X\n", 466 flags)); 467 break; 468 469 case AML_DUAL_NAME_PREFIX: 470 471 /* More than one name_seg, search rules do not apply */ 472 473 search_parent_flag = ACPI_NS_NO_UPSEARCH; 474 475 /* Two segments, point to first name segment */ 476 477 num_segments = 2; 478 path++; 479 480 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 481 "Dual Pathname (2 segments, Flags=%X)\n", 482 flags)); 483 break; 484 485 case AML_MULTI_NAME_PREFIX_OP: 486 487 /* More than one name_seg, search rules do not apply */ 488 489 search_parent_flag = ACPI_NS_NO_UPSEARCH; 490 491 /* Extract segment count, point to first name segment */ 492 493 path++; 494 num_segments = (u32) (u8) * path; 495 path++; 496 497 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 498 "Multi Pathname (%u Segments, Flags=%X)\n", 499 num_segments, flags)); 500 break; 501 502 default: 503 /* 504 * Not a Null name, no Dual or Multi prefix, hence there is 505 * only one name segment and Pathname is already pointing to it. 506 */ 507 num_segments = 1; 508 509 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 510 "Simple Pathname (1 segment, Flags=%X)\n", 511 flags)); 512 break; 513 } 514 515 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path)); 516 } 517 518 /* 519 * Search namespace for each segment of the name. Loop through and 520 * verify (or add to the namespace) each name segment. 521 * 522 * The object type is significant only at the last name 523 * segment. (We don't care about the types along the path, only 524 * the type of the final target object.) 525 */ 526 this_search_type = ACPI_TYPE_ANY; 527 current_node = this_node; 528 while (num_segments && current_node) { 529 num_segments--; 530 if (!num_segments) { 531 532 /* This is the last segment, enable typechecking */ 533 534 this_search_type = type; 535 536 /* 537 * Only allow automatic parent search (search rules) if the caller 538 * requested it AND we have a single, non-fully-qualified name_seg 539 */ 540 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) && 541 (flags & ACPI_NS_SEARCH_PARENT)) { 542 local_flags |= ACPI_NS_SEARCH_PARENT; 543 } 544 545 /* Set error flag according to caller */ 546 547 if (flags & ACPI_NS_ERROR_IF_FOUND) { 548 local_flags |= ACPI_NS_ERROR_IF_FOUND; 549 } 550 } 551 552 /* Extract one ACPI name from the front of the pathname */ 553 554 ACPI_MOVE_32_TO_32(&simple_name, path); 555 556 /* Try to find the single (4 character) ACPI name */ 557 558 status = 559 acpi_ns_search_and_enter(simple_name, walk_state, 560 current_node, interpreter_mode, 561 this_search_type, local_flags, 562 &this_node); 563 if (ACPI_FAILURE(status)) { 564 if (status == AE_NOT_FOUND) { 565 566 /* Name not found in ACPI namespace */ 567 568 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 569 "Name [%4.4s] not found in scope [%4.4s] %p\n", 570 (char *)&simple_name, 571 (char *)¤t_node->name, 572 current_node)); 573 } 574 575 *return_node = this_node; 576 return_ACPI_STATUS(status); 577 } 578 579 /* More segments to follow? */ 580 581 if (num_segments > 0) { 582 /* 583 * If we have an alias to an object that opens a scope (such as a 584 * device or processor), we need to dereference the alias here so 585 * that we can access any children of the original node (via the 586 * remaining segments). 587 */ 588 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) { 589 if (!this_node->object) { 590 return_ACPI_STATUS(AE_NOT_EXIST); 591 } 592 593 if (acpi_ns_opens_scope 594 (((struct acpi_namespace_node *) 595 this_node->object)->type)) { 596 this_node = 597 (struct acpi_namespace_node *) 598 this_node->object; 599 } 600 } 601 } 602 603 /* Special handling for the last segment (num_segments == 0) */ 604 605 else { 606 /* 607 * Sanity typecheck of the target object: 608 * 609 * If 1) This is the last segment (num_segments == 0) 610 * 2) And we are looking for a specific type 611 * (Not checking for TYPE_ANY) 612 * 3) Which is not an alias 613 * 4) Which is not a local type (TYPE_SCOPE) 614 * 5) And the type of target object is known (not TYPE_ANY) 615 * 6) And target object does not match what we are looking for 616 * 617 * Then we have a type mismatch. Just warn and ignore it. 618 */ 619 if ((type_to_check_for != ACPI_TYPE_ANY) && 620 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) && 621 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) 622 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) 623 && (this_node->type != ACPI_TYPE_ANY) 624 && (this_node->type != type_to_check_for)) { 625 626 /* Complain about a type mismatch */ 627 628 ACPI_WARNING((AE_INFO, 629 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)", 630 ACPI_CAST_PTR(char, &simple_name), 631 acpi_ut_get_type_name(this_node-> 632 type), 633 acpi_ut_get_type_name 634 (type_to_check_for))); 635 } 636 637 /* 638 * If this is the last name segment and we are not looking for a 639 * specific type, but the type of found object is known, use that 640 * type to (later) see if it opens a scope. 641 */ 642 if (type == ACPI_TYPE_ANY) { 643 type = this_node->type; 644 } 645 } 646 647 /* Point to next name segment and make this node current */ 648 649 path += ACPI_NAME_SIZE; 650 current_node = this_node; 651 } 652 653 /* Always check if we need to open a new scope */ 654 655 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) { 656 /* 657 * If entry is a type which opens a scope, push the new scope on the 658 * scope stack. 659 */ 660 if (acpi_ns_opens_scope(type)) { 661 status = 662 acpi_ds_scope_stack_push(this_node, type, 663 walk_state); 664 if (ACPI_FAILURE(status)) { 665 return_ACPI_STATUS(status); 666 } 667 } 668 } 669 670 *return_node = this_node; 671 return_ACPI_STATUS(AE_OK); 672 } 673