1 /******************************************************************************* 2 * 3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2012, 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 obj_desc->method.param_count = 155 (u8) ACPI_TO_INTEGER(val); 156 obj_desc->common.flags |= AOPOBJ_DATA_VALID; 157 158 #if defined (ACPI_ASL_COMPILER) 159 160 /* Save the parameter count for the iASL compiler */ 161 162 new_node->value = obj_desc->method.param_count; 163 #else 164 /* Mark this as a very SPECIAL method */ 165 166 obj_desc->method.info_flags = 167 ACPI_METHOD_INTERNAL_ONLY; 168 obj_desc->method.dispatch.implementation = 169 acpi_ut_osi_implementation; 170 #endif 171 break; 172 173 case ACPI_TYPE_INTEGER: 174 175 obj_desc->integer.value = ACPI_TO_INTEGER(val); 176 break; 177 178 case ACPI_TYPE_STRING: 179 180 /* Build an object around the static string */ 181 182 obj_desc->string.length = (u32)ACPI_STRLEN(val); 183 obj_desc->string.pointer = val; 184 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER; 185 break; 186 187 case ACPI_TYPE_MUTEX: 188 189 obj_desc->mutex.node = new_node; 190 obj_desc->mutex.sync_level = 191 (u8) (ACPI_TO_INTEGER(val) - 1); 192 193 /* Create a mutex */ 194 195 status = 196 acpi_os_create_mutex(&obj_desc->mutex. 197 os_mutex); 198 if (ACPI_FAILURE(status)) { 199 acpi_ut_remove_reference(obj_desc); 200 goto unlock_and_exit; 201 } 202 203 /* Special case for ACPI Global Lock */ 204 205 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) { 206 acpi_gbl_global_lock_mutex = obj_desc; 207 208 /* Create additional counting semaphore for global lock */ 209 210 status = 211 acpi_os_create_semaphore(1, 0, 212 &acpi_gbl_global_lock_semaphore); 213 if (ACPI_FAILURE(status)) { 214 acpi_ut_remove_reference 215 (obj_desc); 216 goto unlock_and_exit; 217 } 218 } 219 break; 220 221 default: 222 223 ACPI_ERROR((AE_INFO, 224 "Unsupported initial type value 0x%X", 225 init_val->type)); 226 acpi_ut_remove_reference(obj_desc); 227 obj_desc = NULL; 228 continue; 229 } 230 231 /* Store pointer to value descriptor in the Node */ 232 233 status = acpi_ns_attach_object(new_node, obj_desc, 234 obj_desc->common.type); 235 236 /* Remove local reference to the object */ 237 238 acpi_ut_remove_reference(obj_desc); 239 } 240 } 241 242 unlock_and_exit: 243 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); 244 245 /* Save a handle to "_GPE", it is always present */ 246 247 if (ACPI_SUCCESS(status)) { 248 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH, 249 &acpi_gbl_fadt_gpe_device); 250 } 251 252 return_ACPI_STATUS(status); 253 } 254 255 /******************************************************************************* 256 * 257 * FUNCTION: acpi_ns_lookup 258 * 259 * PARAMETERS: scope_info - Current scope info block 260 * pathname - Search pathname, in internal format 261 * (as represented in the AML stream) 262 * type - Type associated with name 263 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found 264 * flags - Flags describing the search restrictions 265 * walk_state - Current state of the walk 266 * return_node - Where the Node is placed (if found 267 * or created successfully) 268 * 269 * RETURN: Status 270 * 271 * DESCRIPTION: Find or enter the passed name in the name space. 272 * Log an error if name not found in Exec mode. 273 * 274 * MUTEX: Assumes namespace is locked. 275 * 276 ******************************************************************************/ 277 278 acpi_status 279 acpi_ns_lookup(union acpi_generic_state *scope_info, 280 char *pathname, 281 acpi_object_type type, 282 acpi_interpreter_mode interpreter_mode, 283 u32 flags, 284 struct acpi_walk_state *walk_state, 285 struct acpi_namespace_node **return_node) 286 { 287 acpi_status status; 288 char *path = pathname; 289 struct acpi_namespace_node *prefix_node; 290 struct acpi_namespace_node *current_node = NULL; 291 struct acpi_namespace_node *this_node = NULL; 292 u32 num_segments; 293 u32 num_carats; 294 acpi_name simple_name; 295 acpi_object_type type_to_check_for; 296 acpi_object_type this_search_type; 297 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT; 298 u32 local_flags; 299 300 ACPI_FUNCTION_TRACE(ns_lookup); 301 302 if (!return_node) { 303 return_ACPI_STATUS(AE_BAD_PARAMETER); 304 } 305 306 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT); 307 *return_node = ACPI_ENTRY_NOT_FOUND; 308 acpi_gbl_ns_lookup_count++; 309 310 if (!acpi_gbl_root_node) { 311 return_ACPI_STATUS(AE_NO_NAMESPACE); 312 } 313 314 /* Get the prefix scope. A null scope means use the root scope */ 315 316 if ((!scope_info) || (!scope_info->scope.node)) { 317 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 318 "Null scope prefix, using root node (%p)\n", 319 acpi_gbl_root_node)); 320 321 prefix_node = acpi_gbl_root_node; 322 } else { 323 prefix_node = scope_info->scope.node; 324 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) != 325 ACPI_DESC_TYPE_NAMED) { 326 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]", 327 prefix_node, 328 acpi_ut_get_descriptor_name(prefix_node))); 329 return_ACPI_STATUS(AE_AML_INTERNAL); 330 } 331 332 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) { 333 /* 334 * This node might not be a actual "scope" node (such as a 335 * Device/Method, etc.) It could be a Package or other object 336 * node. Backup up the tree to find the containing scope node. 337 */ 338 while (!acpi_ns_opens_scope(prefix_node->type) && 339 prefix_node->type != ACPI_TYPE_ANY) { 340 prefix_node = prefix_node->parent; 341 } 342 } 343 } 344 345 /* Save type. TBD: may be no longer necessary */ 346 347 type_to_check_for = type; 348 349 /* 350 * Begin examination of the actual pathname 351 */ 352 if (!pathname) { 353 354 /* A Null name_path is allowed and refers to the root */ 355 356 num_segments = 0; 357 this_node = acpi_gbl_root_node; 358 path = ""; 359 360 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 361 "Null Pathname (Zero segments), Flags=%X\n", 362 flags)); 363 } else { 364 /* 365 * Name pointer is valid (and must be in internal name format) 366 * 367 * Check for scope prefixes: 368 * 369 * As represented in the AML stream, a namepath consists of an 370 * optional scope prefix followed by a name segment part. 371 * 372 * If present, the scope prefix is either a Root Prefix (in 373 * which case the name is fully qualified), or one or more 374 * Parent Prefixes (in which case the name's scope is relative 375 * to the current scope). 376 */ 377 if (*path == (u8) AML_ROOT_PREFIX) { 378 379 /* Pathname is fully qualified, start from the root */ 380 381 this_node = acpi_gbl_root_node; 382 search_parent_flag = ACPI_NS_NO_UPSEARCH; 383 384 /* Point to name segment part */ 385 386 path++; 387 388 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 389 "Path is absolute from root [%p]\n", 390 this_node)); 391 } else { 392 /* Pathname is relative to current scope, start there */ 393 394 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 395 "Searching relative to prefix scope [%4.4s] (%p)\n", 396 acpi_ut_get_node_name(prefix_node), 397 prefix_node)); 398 399 /* 400 * Handle multiple Parent Prefixes (carat) by just getting 401 * the parent node for each prefix instance. 402 */ 403 this_node = prefix_node; 404 num_carats = 0; 405 while (*path == (u8) AML_PARENT_PREFIX) { 406 407 /* Name is fully qualified, no search rules apply */ 408 409 search_parent_flag = ACPI_NS_NO_UPSEARCH; 410 411 /* 412 * Point past this prefix to the name segment 413 * part or the next Parent Prefix 414 */ 415 path++; 416 417 /* Backup to the parent node */ 418 419 num_carats++; 420 this_node = this_node->parent; 421 if (!this_node) { 422 423 /* Current scope has no parent scope */ 424 425 ACPI_ERROR((AE_INFO, 426 "ACPI path has too many parent prefixes (^) " 427 "- reached beyond root node")); 428 return_ACPI_STATUS(AE_NOT_FOUND); 429 } 430 } 431 432 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) { 433 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 434 "Search scope is [%4.4s], path has %u carat(s)\n", 435 acpi_ut_get_node_name 436 (this_node), num_carats)); 437 } 438 } 439 440 /* 441 * Determine the number of ACPI name segments in this pathname. 442 * 443 * The segment part consists of either: 444 * - A Null name segment (0) 445 * - A dual_name_prefix followed by two 4-byte name segments 446 * - A multi_name_prefix followed by a byte indicating the 447 * number of segments and the segments themselves. 448 * - A single 4-byte name segment 449 * 450 * Examine the name prefix opcode, if any, to determine the number of 451 * segments. 452 */ 453 switch (*path) { 454 case 0: 455 /* 456 * Null name after a root or parent prefixes. We already 457 * have the correct target node and there are no name segments. 458 */ 459 num_segments = 0; 460 type = this_node->type; 461 462 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 463 "Prefix-only Pathname (Zero name segments), Flags=%X\n", 464 flags)); 465 break; 466 467 case AML_DUAL_NAME_PREFIX: 468 469 /* More than one name_seg, search rules do not apply */ 470 471 search_parent_flag = ACPI_NS_NO_UPSEARCH; 472 473 /* Two segments, point to first name segment */ 474 475 num_segments = 2; 476 path++; 477 478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 479 "Dual Pathname (2 segments, Flags=%X)\n", 480 flags)); 481 break; 482 483 case AML_MULTI_NAME_PREFIX_OP: 484 485 /* More than one name_seg, search rules do not apply */ 486 487 search_parent_flag = ACPI_NS_NO_UPSEARCH; 488 489 /* Extract segment count, point to first name segment */ 490 491 path++; 492 num_segments = (u32) (u8) * path; 493 path++; 494 495 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 496 "Multi Pathname (%u Segments, Flags=%X)\n", 497 num_segments, flags)); 498 break; 499 500 default: 501 /* 502 * Not a Null name, no Dual or Multi prefix, hence there is 503 * only one name segment and Pathname is already pointing to it. 504 */ 505 num_segments = 1; 506 507 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 508 "Simple Pathname (1 segment, Flags=%X)\n", 509 flags)); 510 break; 511 } 512 513 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path)); 514 } 515 516 /* 517 * Search namespace for each segment of the name. Loop through and 518 * verify (or add to the namespace) each name segment. 519 * 520 * The object type is significant only at the last name 521 * segment. (We don't care about the types along the path, only 522 * the type of the final target object.) 523 */ 524 this_search_type = ACPI_TYPE_ANY; 525 current_node = this_node; 526 while (num_segments && current_node) { 527 num_segments--; 528 if (!num_segments) { 529 530 /* This is the last segment, enable typechecking */ 531 532 this_search_type = type; 533 534 /* 535 * Only allow automatic parent search (search rules) if the caller 536 * requested it AND we have a single, non-fully-qualified name_seg 537 */ 538 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) && 539 (flags & ACPI_NS_SEARCH_PARENT)) { 540 local_flags |= ACPI_NS_SEARCH_PARENT; 541 } 542 543 /* Set error flag according to caller */ 544 545 if (flags & ACPI_NS_ERROR_IF_FOUND) { 546 local_flags |= ACPI_NS_ERROR_IF_FOUND; 547 } 548 } 549 550 /* Extract one ACPI name from the front of the pathname */ 551 552 ACPI_MOVE_32_TO_32(&simple_name, path); 553 554 /* Try to find the single (4 character) ACPI name */ 555 556 status = 557 acpi_ns_search_and_enter(simple_name, walk_state, 558 current_node, interpreter_mode, 559 this_search_type, local_flags, 560 &this_node); 561 if (ACPI_FAILURE(status)) { 562 if (status == AE_NOT_FOUND) { 563 564 /* Name not found in ACPI namespace */ 565 566 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 567 "Name [%4.4s] not found in scope [%4.4s] %p\n", 568 (char *)&simple_name, 569 (char *)¤t_node->name, 570 current_node)); 571 } 572 573 *return_node = this_node; 574 return_ACPI_STATUS(status); 575 } 576 577 /* More segments to follow? */ 578 579 if (num_segments > 0) { 580 /* 581 * If we have an alias to an object that opens a scope (such as a 582 * device or processor), we need to dereference the alias here so 583 * that we can access any children of the original node (via the 584 * remaining segments). 585 */ 586 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) { 587 if (!this_node->object) { 588 return_ACPI_STATUS(AE_NOT_EXIST); 589 } 590 591 if (acpi_ns_opens_scope 592 (((struct acpi_namespace_node *) 593 this_node->object)->type)) { 594 this_node = 595 (struct acpi_namespace_node *) 596 this_node->object; 597 } 598 } 599 } 600 601 /* Special handling for the last segment (num_segments == 0) */ 602 603 else { 604 /* 605 * Sanity typecheck of the target object: 606 * 607 * If 1) This is the last segment (num_segments == 0) 608 * 2) And we are looking for a specific type 609 * (Not checking for TYPE_ANY) 610 * 3) Which is not an alias 611 * 4) Which is not a local type (TYPE_SCOPE) 612 * 5) And the type of target object is known (not TYPE_ANY) 613 * 6) And target object does not match what we are looking for 614 * 615 * Then we have a type mismatch. Just warn and ignore it. 616 */ 617 if ((type_to_check_for != ACPI_TYPE_ANY) && 618 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) && 619 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) 620 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) 621 && (this_node->type != ACPI_TYPE_ANY) 622 && (this_node->type != type_to_check_for)) { 623 624 /* Complain about a type mismatch */ 625 626 ACPI_WARNING((AE_INFO, 627 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)", 628 ACPI_CAST_PTR(char, &simple_name), 629 acpi_ut_get_type_name(this_node-> 630 type), 631 acpi_ut_get_type_name 632 (type_to_check_for))); 633 } 634 635 /* 636 * If this is the last name segment and we are not looking for a 637 * specific type, but the type of found object is known, use that 638 * type to (later) see if it opens a scope. 639 */ 640 if (type == ACPI_TYPE_ANY) { 641 type = this_node->type; 642 } 643 } 644 645 /* Point to next name segment and make this node current */ 646 647 path += ACPI_NAME_SIZE; 648 current_node = this_node; 649 } 650 651 /* Always check if we need to open a new scope */ 652 653 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) { 654 /* 655 * If entry is a type which opens a scope, push the new scope on the 656 * scope stack. 657 */ 658 if (acpi_ns_opens_scope(type)) { 659 status = 660 acpi_ds_scope_stack_push(this_node, type, 661 walk_state); 662 if (ACPI_FAILURE(status)) { 663 return_ACPI_STATUS(status); 664 } 665 } 666 } 667 668 *return_node = this_node; 669 return_ACPI_STATUS(AE_OK); 670 } 671