nsaccess.c revision 3371c19c294a4cb3649aa4e84606be8a1d999e61
1/******************************************************************************* 2 * 3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace 4 * 5 ******************************************************************************/ 6 7/* 8 * Copyright (C) 2000 - 2008, 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 51ACPI_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 ******************************************************************************/ 66acpi_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); 113 114 if (ACPI_FAILURE(status) || (!new_node)) { /* Must be on same line for code converter */ 115 ACPI_EXCEPTION((AE_INFO, status, 116 "Could not create predefined name %s", 117 init_val->name)); 118 } 119 120 /* 121 * Name entered successfully. 122 * If entry in pre_defined_names[] specifies an 123 * initial value, create the initial value. 124 */ 125 if (init_val->val) { 126 status = acpi_os_predefined_override(init_val, &val); 127 if (ACPI_FAILURE(status)) { 128 ACPI_ERROR((AE_INFO, 129 "Could not override predefined %s", 130 init_val->name)); 131 } 132 133 if (!val) { 134 val = init_val->val; 135 } 136 137 /* 138 * Entry requests an initial value, allocate a 139 * descriptor for it. 140 */ 141 obj_desc = 142 acpi_ut_create_internal_object(init_val->type); 143 if (!obj_desc) { 144 status = AE_NO_MEMORY; 145 goto unlock_and_exit; 146 } 147 148 /* 149 * Convert value string from table entry to 150 * internal representation. Only types actually 151 * used for initial values are implemented here. 152 */ 153 switch (init_val->type) { 154 case ACPI_TYPE_METHOD: 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 i_aSL 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.method_flags = 168 AML_METHOD_INTERNAL_ONLY; 169 obj_desc->method.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 /* 182 * Build an object around the static string 183 */ 184 obj_desc->string.length = 185 (u32) ACPI_STRLEN(val); 186 obj_desc->string.pointer = val; 187 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER; 188 break; 189 190 case ACPI_TYPE_MUTEX: 191 192 obj_desc->mutex.node = new_node; 193 obj_desc->mutex.sync_level = 194 (u8) (ACPI_TO_INTEGER(val) - 1); 195 196 /* Create a mutex */ 197 198 status = 199 acpi_os_create_mutex(&obj_desc->mutex. 200 os_mutex); 201 if (ACPI_FAILURE(status)) { 202 acpi_ut_remove_reference(obj_desc); 203 goto unlock_and_exit; 204 } 205 206 /* Special case for ACPI Global Lock */ 207 208 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) { 209 acpi_gbl_global_lock_mutex = obj_desc; 210 211 /* Create additional counting semaphore for global lock */ 212 213 status = 214 acpi_os_create_semaphore(1, 0, 215 &acpi_gbl_global_lock_semaphore); 216 if (ACPI_FAILURE(status)) { 217 acpi_ut_remove_reference 218 (obj_desc); 219 goto unlock_and_exit; 220 } 221 } 222 break; 223 224 default: 225 226 ACPI_ERROR((AE_INFO, 227 "Unsupported initial type value %X", 228 init_val->type)); 229 acpi_ut_remove_reference(obj_desc); 230 obj_desc = NULL; 231 continue; 232 } 233 234 /* Store pointer to value descriptor in the Node */ 235 236 status = acpi_ns_attach_object(new_node, obj_desc, 237 obj_desc->common.type); 238 239 /* Remove local reference to the object */ 240 241 acpi_ut_remove_reference(obj_desc); 242 } 243 } 244 245 unlock_and_exit: 246 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE); 247 248 /* Save a handle to "_GPE", it is always present */ 249 250 if (ACPI_SUCCESS(status)) { 251 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH, 252 &acpi_gbl_fadt_gpe_device); 253 } 254 255 return_ACPI_STATUS(status); 256} 257 258/******************************************************************************* 259 * 260 * FUNCTION: acpi_ns_lookup 261 * 262 * PARAMETERS: scope_info - Current scope info block 263 * Pathname - Search pathname, in internal format 264 * (as represented in the AML stream) 265 * Type - Type associated with name 266 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found 267 * Flags - Flags describing the search restrictions 268 * walk_state - Current state of the walk 269 * return_node - Where the Node is placed (if found 270 * or created successfully) 271 * 272 * RETURN: Status 273 * 274 * DESCRIPTION: Find or enter the passed name in the name space. 275 * Log an error if name not found in Exec mode. 276 * 277 * MUTEX: Assumes namespace is locked. 278 * 279 ******************************************************************************/ 280 281acpi_status 282acpi_ns_lookup(union acpi_generic_state *scope_info, 283 char *pathname, 284 acpi_object_type type, 285 acpi_interpreter_mode interpreter_mode, 286 u32 flags, 287 struct acpi_walk_state *walk_state, 288 struct acpi_namespace_node **return_node) 289{ 290 acpi_status status; 291 char *path = pathname; 292 struct acpi_namespace_node *prefix_node; 293 struct acpi_namespace_node *current_node = NULL; 294 struct acpi_namespace_node *this_node = NULL; 295 u32 num_segments; 296 u32 num_carats; 297 acpi_name simple_name; 298 acpi_object_type type_to_check_for; 299 acpi_object_type this_search_type; 300 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT; 301 u32 local_flags; 302 303 ACPI_FUNCTION_TRACE(ns_lookup); 304 305 if (!return_node) { 306 return_ACPI_STATUS(AE_BAD_PARAMETER); 307 } 308 309 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT); 310 *return_node = ACPI_ENTRY_NOT_FOUND; 311 acpi_gbl_ns_lookup_count++; 312 313 if (!acpi_gbl_root_node) { 314 return_ACPI_STATUS(AE_NO_NAMESPACE); 315 } 316 317 /* 318 * Get the prefix scope. 319 * A null scope means use the root scope 320 */ 321 if ((!scope_info) || (!scope_info->scope.node)) { 322 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 323 "Null scope prefix, using root node (%p)\n", 324 acpi_gbl_root_node)); 325 326 prefix_node = acpi_gbl_root_node; 327 } else { 328 prefix_node = scope_info->scope.node; 329 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) != 330 ACPI_DESC_TYPE_NAMED) { 331 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]", 332 prefix_node, 333 acpi_ut_get_descriptor_name(prefix_node))); 334 return_ACPI_STATUS(AE_AML_INTERNAL); 335 } 336 337 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) { 338 /* 339 * This node might not be a actual "scope" node (such as a 340 * Device/Method, etc.) It could be a Package or other object node. 341 * Backup up the tree to find the containing scope node. 342 */ 343 while (!acpi_ns_opens_scope(prefix_node->type) && 344 prefix_node->type != ACPI_TYPE_ANY) { 345 prefix_node = 346 acpi_ns_get_parent_node(prefix_node); 347 } 348 } 349 } 350 351 /* Save type TBD: may be no longer necessary */ 352 353 type_to_check_for = type; 354 355 /* 356 * Begin examination of the actual pathname 357 */ 358 if (!pathname) { 359 360 /* A Null name_path is allowed and refers to the root */ 361 362 num_segments = 0; 363 this_node = acpi_gbl_root_node; 364 path = ""; 365 366 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 367 "Null Pathname (Zero segments), Flags=%X\n", 368 flags)); 369 } else { 370 /* 371 * Name pointer is valid (and must be in internal name format) 372 * 373 * Check for scope prefixes: 374 * 375 * As represented in the AML stream, a namepath consists of an 376 * optional scope prefix followed by a name segment part. 377 * 378 * If present, the scope prefix is either a Root Prefix (in 379 * which case the name is fully qualified), or one or more 380 * Parent Prefixes (in which case the name's scope is relative 381 * to the current scope). 382 */ 383 if (*path == (u8) AML_ROOT_PREFIX) { 384 385 /* Pathname is fully qualified, start from the root */ 386 387 this_node = acpi_gbl_root_node; 388 search_parent_flag = ACPI_NS_NO_UPSEARCH; 389 390 /* Point to name segment part */ 391 392 path++; 393 394 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 395 "Path is absolute from root [%p]\n", 396 this_node)); 397 } else { 398 /* Pathname is relative to current scope, start there */ 399 400 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 401 "Searching relative to prefix scope [%4.4s] (%p)\n", 402 acpi_ut_get_node_name(prefix_node), 403 prefix_node)); 404 405 /* 406 * Handle multiple Parent Prefixes (carat) by just getting 407 * the parent node for each prefix instance. 408 */ 409 this_node = prefix_node; 410 num_carats = 0; 411 while (*path == (u8) AML_PARENT_PREFIX) { 412 413 /* Name is fully qualified, no search rules apply */ 414 415 search_parent_flag = ACPI_NS_NO_UPSEARCH; 416 /* 417 * Point past this prefix to the name segment 418 * part or the next Parent Prefix 419 */ 420 path++; 421 422 /* Backup to the parent node */ 423 424 num_carats++; 425 this_node = acpi_ns_get_parent_node(this_node); 426 if (!this_node) { 427 428 /* Current scope has no parent scope */ 429 430 ACPI_ERROR((AE_INFO, 431 "ACPI path has too many parent prefixes (^) - reached beyond root node")); 432 return_ACPI_STATUS(AE_NOT_FOUND); 433 } 434 } 435 436 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) { 437 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 438 "Search scope is [%4.4s], path has %d carat(s)\n", 439 acpi_ut_get_node_name 440 (this_node), num_carats)); 441 } 442 } 443 444 /* 445 * Determine the number of ACPI name segments in this pathname. 446 * 447 * The segment part consists of either: 448 * - A Null name segment (0) 449 * - A dual_name_prefix followed by two 4-byte name segments 450 * - A multi_name_prefix followed by a byte indicating the 451 * number of segments and the segments themselves. 452 * - A single 4-byte name segment 453 * 454 * Examine the name prefix opcode, if any, to determine the number of 455 * segments. 456 */ 457 switch (*path) { 458 case 0: 459 /* 460 * Null name after a root or parent prefixes. We already 461 * have the correct target node and there are no name segments. 462 */ 463 num_segments = 0; 464 type = this_node->type; 465 466 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 467 "Prefix-only Pathname (Zero name segments), Flags=%X\n", 468 flags)); 469 break; 470 471 case AML_DUAL_NAME_PREFIX: 472 473 /* More than one name_seg, search rules do not apply */ 474 475 search_parent_flag = ACPI_NS_NO_UPSEARCH; 476 477 /* Two segments, point to first name segment */ 478 479 num_segments = 2; 480 path++; 481 482 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 483 "Dual Pathname (2 segments, Flags=%X)\n", 484 flags)); 485 break; 486 487 case AML_MULTI_NAME_PREFIX_OP: 488 489 /* More than one name_seg, search rules do not apply */ 490 491 search_parent_flag = ACPI_NS_NO_UPSEARCH; 492 493 /* Extract segment count, point to first name segment */ 494 495 path++; 496 num_segments = (u32) (u8) * path; 497 path++; 498 499 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 500 "Multi Pathname (%d Segments, Flags=%X)\n", 501 num_segments, flags)); 502 break; 503 504 default: 505 /* 506 * Not a Null name, no Dual or Multi prefix, hence there is 507 * only one name segment and Pathname is already pointing to it. 508 */ 509 num_segments = 1; 510 511 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 512 "Simple Pathname (1 segment, Flags=%X)\n", 513 flags)); 514 break; 515 } 516 517 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path)); 518 } 519 520 /* 521 * Search namespace for each segment of the name. Loop through and 522 * verify (or add to the namespace) each name segment. 523 * 524 * The object type is significant only at the last name 525 * segment. (We don't care about the types along the path, only 526 * the type of the final target object.) 527 */ 528 this_search_type = ACPI_TYPE_ANY; 529 current_node = this_node; 530 while (num_segments && current_node) { 531 num_segments--; 532 if (!num_segments) { 533 /* 534 * This is the last segment, enable typechecking 535 */ 536 this_search_type = type; 537 538 /* 539 * Only allow automatic parent search (search rules) if the caller 540 * requested it AND we have a single, non-fully-qualified name_seg 541 */ 542 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) && 543 (flags & ACPI_NS_SEARCH_PARENT)) { 544 local_flags |= ACPI_NS_SEARCH_PARENT; 545 } 546 547 /* Set error flag according to caller */ 548 549 if (flags & ACPI_NS_ERROR_IF_FOUND) { 550 local_flags |= ACPI_NS_ERROR_IF_FOUND; 551 } 552 } 553 554 /* Extract one ACPI name from the front of the pathname */ 555 556 ACPI_MOVE_32_TO_32(&simple_name, path); 557 558 /* Try to find the single (4 character) ACPI name */ 559 560 status = 561 acpi_ns_search_and_enter(simple_name, walk_state, 562 current_node, interpreter_mode, 563 this_search_type, local_flags, 564 &this_node); 565 if (ACPI_FAILURE(status)) { 566 if (status == AE_NOT_FOUND) { 567 568 /* Name not found in ACPI namespace */ 569 570 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 571 "Name [%4.4s] not found in scope [%4.4s] %p\n", 572 (char *)&simple_name, 573 (char *)¤t_node->name, 574 current_node)); 575 } 576 577 *return_node = this_node; 578 return_ACPI_STATUS(status); 579 } 580 581 /* More segments to follow? */ 582 583 if (num_segments > 0) { 584 /* 585 * If we have an alias to an object that opens a scope (such as a 586 * device or processor), we need to dereference the alias here so that 587 * we can access any children of the original node (via the remaining 588 * segments). 589 */ 590 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) { 591 if (!this_node->object) { 592 return_ACPI_STATUS(AE_NOT_EXIST); 593 } 594 595 if (acpi_ns_opens_scope 596 (((struct acpi_namespace_node *)this_node-> 597 object)->type)) { 598 this_node = 599 (struct acpi_namespace_node *) 600 this_node->object; 601 } 602 } 603 } 604 605 /* Special handling for the last segment (num_segments == 0) */ 606 607 else { 608 /* 609 * Sanity typecheck of the target object: 610 * 611 * If 1) This is the last segment (num_segments == 0) 612 * 2) And we are looking for a specific type 613 * (Not checking for TYPE_ANY) 614 * 3) Which is not an alias 615 * 4) Which is not a local type (TYPE_SCOPE) 616 * 5) And the type of target object is known (not TYPE_ANY) 617 * 6) And target object does not match what we are looking for 618 * 619 * Then we have a type mismatch. Just warn and ignore it. 620 */ 621 if ((type_to_check_for != ACPI_TYPE_ANY) && 622 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) && 623 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) 624 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) 625 && (this_node->type != ACPI_TYPE_ANY) 626 && (this_node->type != type_to_check_for)) { 627 628 /* Complain about a type mismatch */ 629 630 ACPI_WARNING((AE_INFO, 631 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)", 632 ACPI_CAST_PTR(char, &simple_name), 633 acpi_ut_get_type_name(this_node-> 634 type), 635 acpi_ut_get_type_name 636 (type_to_check_for))); 637 } 638 639 /* 640 * If this is the last name segment and we are not looking for a 641 * specific type, but the type of found object is known, use that type 642 * to (later) see if it opens a scope. 643 */ 644 if (type == ACPI_TYPE_ANY) { 645 type = this_node->type; 646 } 647 } 648 649 /* Point to next name segment and make this node current */ 650 651 path += ACPI_NAME_SIZE; 652 current_node = this_node; 653 } 654 655 /* 656 * Always check if we need to open a new scope 657 */ 658 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) { 659 /* 660 * If entry is a type which opens a scope, push the new scope on the 661 * scope stack. 662 */ 663 if (acpi_ns_opens_scope(type)) { 664 status = 665 acpi_ds_scope_stack_push(this_node, type, 666 walk_state); 667 if (ACPI_FAILURE(status)) { 668 return_ACPI_STATUS(status); 669 } 670 } 671 } 672 673 *return_node = this_node; 674 return_ACPI_STATUS(AE_OK); 675} 676