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); 113 114 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. 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 = 183 (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 "ACPI path has too many parent prefixes (^) " 428 "- reached beyond root node")); 429 return_ACPI_STATUS(AE_NOT_FOUND); 430 } 431 } 432 433 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) { 434 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 435 "Search scope is [%4.4s], path has %u carat(s)\n", 436 acpi_ut_get_node_name 437 (this_node), num_carats)); 438 } 439 } 440 441 /* 442 * Determine the number of ACPI name segments in this pathname. 443 * 444 * The segment part consists of either: 445 * - A Null name segment (0) 446 * - A dual_name_prefix followed by two 4-byte name segments 447 * - A multi_name_prefix followed by a byte indicating the 448 * number of segments and the segments themselves. 449 * - A single 4-byte name segment 450 * 451 * Examine the name prefix opcode, if any, to determine the number of 452 * segments. 453 */ 454 switch (*path) { 455 case 0: 456 /* 457 * Null name after a root or parent prefixes. We already 458 * have the correct target node and there are no name segments. 459 */ 460 num_segments = 0; 461 type = this_node->type; 462 463 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 464 "Prefix-only Pathname (Zero name segments), Flags=%X\n", 465 flags)); 466 break; 467 468 case AML_DUAL_NAME_PREFIX: 469 470 /* More than one name_seg, search rules do not apply */ 471 472 search_parent_flag = ACPI_NS_NO_UPSEARCH; 473 474 /* Two segments, point to first name segment */ 475 476 num_segments = 2; 477 path++; 478 479 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 480 "Dual Pathname (2 segments, Flags=%X)\n", 481 flags)); 482 break; 483 484 case AML_MULTI_NAME_PREFIX_OP: 485 486 /* More than one name_seg, search rules do not apply */ 487 488 search_parent_flag = ACPI_NS_NO_UPSEARCH; 489 490 /* Extract segment count, point to first name segment */ 491 492 path++; 493 num_segments = (u32) (u8) * path; 494 path++; 495 496 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 497 "Multi Pathname (%u Segments, Flags=%X)\n", 498 num_segments, flags)); 499 break; 500 501 default: 502 /* 503 * Not a Null name, no Dual or Multi prefix, hence there is 504 * only one name segment and Pathname is already pointing to it. 505 */ 506 num_segments = 1; 507 508 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 509 "Simple Pathname (1 segment, Flags=%X)\n", 510 flags)); 511 break; 512 } 513 514 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path)); 515 } 516 517 /* 518 * Search namespace for each segment of the name. Loop through and 519 * verify (or add to the namespace) each name segment. 520 * 521 * The object type is significant only at the last name 522 * segment. (We don't care about the types along the path, only 523 * the type of the final target object.) 524 */ 525 this_search_type = ACPI_TYPE_ANY; 526 current_node = this_node; 527 while (num_segments && current_node) { 528 num_segments--; 529 if (!num_segments) { 530 531 /* This is the last segment, enable typechecking */ 532 533 this_search_type = type; 534 535 /* 536 * Only allow automatic parent search (search rules) if the caller 537 * requested it AND we have a single, non-fully-qualified name_seg 538 */ 539 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) && 540 (flags & ACPI_NS_SEARCH_PARENT)) { 541 local_flags |= ACPI_NS_SEARCH_PARENT; 542 } 543 544 /* Set error flag according to caller */ 545 546 if (flags & ACPI_NS_ERROR_IF_FOUND) { 547 local_flags |= ACPI_NS_ERROR_IF_FOUND; 548 } 549 } 550 551 /* Extract one ACPI name from the front of the pathname */ 552 553 ACPI_MOVE_32_TO_32(&simple_name, path); 554 555 /* Try to find the single (4 character) ACPI name */ 556 557 status = 558 acpi_ns_search_and_enter(simple_name, walk_state, 559 current_node, interpreter_mode, 560 this_search_type, local_flags, 561 &this_node); 562 if (ACPI_FAILURE(status)) { 563 if (status == AE_NOT_FOUND) { 564 565 /* Name not found in ACPI namespace */ 566 567 ACPI_DEBUG_PRINT((ACPI_DB_NAMES, 568 "Name [%4.4s] not found in scope [%4.4s] %p\n", 569 (char *)&simple_name, 570 (char *)¤t_node->name, 571 current_node)); 572 } 573 574 *return_node = this_node; 575 return_ACPI_STATUS(status); 576 } 577 578 /* More segments to follow? */ 579 580 if (num_segments > 0) { 581 /* 582 * If we have an alias to an object that opens a scope (such as a 583 * device or processor), we need to dereference the alias here so 584 * that we can access any children of the original node (via the 585 * remaining segments). 586 */ 587 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) { 588 if (!this_node->object) { 589 return_ACPI_STATUS(AE_NOT_EXIST); 590 } 591 592 if (acpi_ns_opens_scope 593 (((struct acpi_namespace_node *) 594 this_node->object)->type)) { 595 this_node = 596 (struct acpi_namespace_node *) 597 this_node->object; 598 } 599 } 600 } 601 602 /* Special handling for the last segment (num_segments == 0) */ 603 604 else { 605 /* 606 * Sanity typecheck of the target object: 607 * 608 * If 1) This is the last segment (num_segments == 0) 609 * 2) And we are looking for a specific type 610 * (Not checking for TYPE_ANY) 611 * 3) Which is not an alias 612 * 4) Which is not a local type (TYPE_SCOPE) 613 * 5) And the type of target object is known (not TYPE_ANY) 614 * 6) And target object does not match what we are looking for 615 * 616 * Then we have a type mismatch. Just warn and ignore it. 617 */ 618 if ((type_to_check_for != ACPI_TYPE_ANY) && 619 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) && 620 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) 621 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) 622 && (this_node->type != ACPI_TYPE_ANY) 623 && (this_node->type != type_to_check_for)) { 624 625 /* Complain about a type mismatch */ 626 627 ACPI_WARNING((AE_INFO, 628 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)", 629 ACPI_CAST_PTR(char, &simple_name), 630 acpi_ut_get_type_name(this_node-> 631 type), 632 acpi_ut_get_type_name 633 (type_to_check_for))); 634 } 635 636 /* 637 * If this is the last name segment and we are not looking for a 638 * specific type, but the type of found object is known, use that 639 * type to (later) see if it opens a scope. 640 */ 641 if (type == ACPI_TYPE_ANY) { 642 type = this_node->type; 643 } 644 } 645 646 /* Point to next name segment and make this node current */ 647 648 path += ACPI_NAME_SIZE; 649 current_node = this_node; 650 } 651 652 /* Always check if we need to open a new scope */ 653 654 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) { 655 /* 656 * If entry is a type which opens a scope, push the new scope on the 657 * scope stack. 658 */ 659 if (acpi_ns_opens_scope(type)) { 660 status = 661 acpi_ds_scope_stack_push(this_node, type, 662 walk_state); 663 if (ACPI_FAILURE(status)) { 664 return_ACPI_STATUS(status); 665 } 666 } 667 } 668 669 *return_node = this_node; 670 return_ACPI_STATUS(AE_OK); 671 } 672