1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
4 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
6 ******************************************************************************/
14 #ifdef ACPI_ASL_COMPILER
18 #define _COMPONENT ACPI_NAMESPACE
19 ACPI_MODULE_NAME("nsaccess")
21 /*******************************************************************************
23 * FUNCTION: acpi_ns_root_initialize
29 * DESCRIPTION: Allocate and initialize the default root named objects
31 * MUTEX: Locks namespace for entire execution
33 ******************************************************************************/
34 acpi_status acpi_ns_root_initialize(void)
37 const struct acpi_predefined_names *init_val = NULL;
38 struct acpi_namespace_node *new_node;
39 union acpi_operand_object *obj_desc;
40 acpi_string val = NULL;
42 ACPI_FUNCTION_TRACE(ns_root_initialize);
44 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
45 if (ACPI_FAILURE(status)) {
46 return_ACPI_STATUS(status);
50 * The global root ptr is initially NULL, so a non-NULL value indicates
51 * that acpi_ns_root_initialize() has already been called; just return.
53 if (acpi_gbl_root_node) {
59 * Tell the rest of the subsystem that the root is initialized
60 * (This is OK because the namespace is locked)
62 acpi_gbl_root_node = &acpi_gbl_root_node_struct;
64 /* Enter the pre-defined names in the name table */
66 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
67 "Entering predefined entries into namespace\n"));
69 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
71 /* _OSI is optional for now, will be permanent later */
73 if (!strcmp(init_val->name, "_OSI")
74 && !acpi_gbl_create_osi_method) {
79 acpi_ns_lookup(NULL, ACPI_CAST_PTR(char, init_val->name),
80 init_val->type, ACPI_IMODE_LOAD_PASS2,
81 ACPI_NS_NO_UPSEARCH, NULL, &new_node);
82 if (ACPI_FAILURE(status)) {
83 ACPI_EXCEPTION((AE_INFO, status,
84 "Could not create predefined name %s",
90 * Name entered successfully. If entry in pre_defined_names[] specifies
91 * an initial value, create the initial value.
94 status = acpi_os_predefined_override(init_val, &val);
95 if (ACPI_FAILURE(status)) {
97 "Could not override predefined %s",
106 * Entry requests an initial value, allocate a
110 acpi_ut_create_internal_object(init_val->type);
112 status = AE_NO_MEMORY;
113 goto unlock_and_exit;
117 * Convert value string from table entry to
118 * internal representation. Only types actually
119 * used for initial values are implemented here.
121 switch (init_val->type) {
122 case ACPI_TYPE_METHOD:
124 obj_desc->method.param_count =
125 (u8) ACPI_TO_INTEGER(val);
126 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
128 #if defined (ACPI_ASL_COMPILER)
130 /* Save the parameter count for the iASL compiler */
132 new_node->value = obj_desc->method.param_count;
134 /* Mark this as a very SPECIAL method */
136 obj_desc->method.info_flags =
137 ACPI_METHOD_INTERNAL_ONLY;
138 obj_desc->method.dispatch.implementation =
139 acpi_ut_osi_implementation;
143 case ACPI_TYPE_INTEGER:
145 obj_desc->integer.value = ACPI_TO_INTEGER(val);
148 case ACPI_TYPE_STRING:
150 /* Build an object around the static string */
152 obj_desc->string.length = (u32)strlen(val);
153 obj_desc->string.pointer = val;
154 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
157 case ACPI_TYPE_MUTEX:
159 obj_desc->mutex.node = new_node;
160 obj_desc->mutex.sync_level =
161 (u8) (ACPI_TO_INTEGER(val) - 1);
166 acpi_os_create_mutex(&obj_desc->mutex.
168 if (ACPI_FAILURE(status)) {
169 acpi_ut_remove_reference(obj_desc);
170 goto unlock_and_exit;
173 /* Special case for ACPI Global Lock */
175 if (strcmp(init_val->name, "_GL_") == 0) {
176 acpi_gbl_global_lock_mutex = obj_desc;
178 /* Create additional counting semaphore for global lock */
181 acpi_os_create_semaphore(1, 0,
182 &acpi_gbl_global_lock_semaphore);
183 if (ACPI_FAILURE(status)) {
184 acpi_ut_remove_reference
186 goto unlock_and_exit;
194 "Unsupported initial type value 0x%X",
196 acpi_ut_remove_reference(obj_desc);
201 /* Store pointer to value descriptor in the Node */
203 status = acpi_ns_attach_object(new_node, obj_desc,
204 obj_desc->common.type);
206 /* Remove local reference to the object */
208 acpi_ut_remove_reference(obj_desc);
213 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
215 /* Save a handle to "_GPE", it is always present */
217 if (ACPI_SUCCESS(status)) {
218 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
219 &acpi_gbl_fadt_gpe_device);
222 return_ACPI_STATUS(status);
225 /*******************************************************************************
227 * FUNCTION: acpi_ns_lookup
229 * PARAMETERS: scope_info - Current scope info block
230 * pathname - Search pathname, in internal format
231 * (as represented in the AML stream)
232 * type - Type associated with name
233 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
234 * flags - Flags describing the search restrictions
235 * walk_state - Current state of the walk
236 * return_node - Where the Node is placed (if found
237 * or created successfully)
241 * DESCRIPTION: Find or enter the passed name in the name space.
242 * Log an error if name not found in Exec mode.
244 * MUTEX: Assumes namespace is locked.
246 ******************************************************************************/
249 acpi_ns_lookup(union acpi_generic_state *scope_info,
251 acpi_object_type type,
252 acpi_interpreter_mode interpreter_mode,
254 struct acpi_walk_state *walk_state,
255 struct acpi_namespace_node **return_node)
258 char *path = pathname;
260 struct acpi_namespace_node *prefix_node;
261 struct acpi_namespace_node *current_node = NULL;
262 struct acpi_namespace_node *this_node = NULL;
265 acpi_name simple_name;
266 acpi_object_type type_to_check_for;
267 acpi_object_type this_search_type;
268 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
270 acpi_interpreter_mode local_interpreter_mode;
272 ACPI_FUNCTION_TRACE(ns_lookup);
275 return_ACPI_STATUS(AE_BAD_PARAMETER);
278 local_flags = flags &
279 ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
280 ACPI_NS_SEARCH_PARENT);
281 *return_node = ACPI_ENTRY_NOT_FOUND;
282 acpi_gbl_ns_lookup_count++;
284 if (!acpi_gbl_root_node) {
285 return_ACPI_STATUS(AE_NO_NAMESPACE);
288 /* Get the prefix scope. A null scope means use the root scope */
290 if ((!scope_info) || (!scope_info->scope.node)) {
291 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
292 "Null scope prefix, using root node (%p)\n",
293 acpi_gbl_root_node));
295 prefix_node = acpi_gbl_root_node;
297 prefix_node = scope_info->scope.node;
298 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
299 ACPI_DESC_TYPE_NAMED) {
300 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
302 acpi_ut_get_descriptor_name(prefix_node)));
303 return_ACPI_STATUS(AE_AML_INTERNAL);
306 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
308 * This node might not be a actual "scope" node (such as a
309 * Device/Method, etc.) It could be a Package or other object
310 * node. Backup up the tree to find the containing scope node.
312 while (!acpi_ns_opens_scope(prefix_node->type) &&
313 prefix_node->type != ACPI_TYPE_ANY) {
314 prefix_node = prefix_node->parent;
319 /* Save type. TBD: may be no longer necessary */
321 type_to_check_for = type;
324 * Begin examination of the actual pathname
328 /* A Null name_path is allowed and refers to the root */
331 this_node = acpi_gbl_root_node;
334 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
335 "Null Pathname (Zero segments), Flags=%X\n",
339 * Name pointer is valid (and must be in internal name format)
341 * Check for scope prefixes:
343 * As represented in the AML stream, a namepath consists of an
344 * optional scope prefix followed by a name segment part.
346 * If present, the scope prefix is either a Root Prefix (in
347 * which case the name is fully qualified), or one or more
348 * Parent Prefixes (in which case the name's scope is relative
349 * to the current scope).
351 if (*path == (u8) AML_ROOT_PREFIX) {
353 /* Pathname is fully qualified, start from the root */
355 this_node = acpi_gbl_root_node;
356 search_parent_flag = ACPI_NS_NO_UPSEARCH;
358 /* Point to name segment part */
362 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
363 "Path is absolute from root [%p]\n",
366 /* Pathname is relative to current scope, start there */
368 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
369 "Searching relative to prefix scope [%4.4s] (%p)\n",
370 acpi_ut_get_node_name(prefix_node),
374 * Handle multiple Parent Prefixes (carat) by just getting
375 * the parent node for each prefix instance.
377 this_node = prefix_node;
379 while (*path == (u8) AML_PARENT_PREFIX) {
381 /* Name is fully qualified, no search rules apply */
383 search_parent_flag = ACPI_NS_NO_UPSEARCH;
386 * Point past this prefix to the name segment
387 * part or the next Parent Prefix
391 /* Backup to the parent node */
394 this_node = this_node->parent;
397 * Current scope has no parent scope. Externalize
398 * the internal path for error message.
401 acpi_ns_externalize_name
402 (ACPI_UINT32_MAX, pathname, NULL,
404 if (ACPI_SUCCESS(status)) {
406 "%s: Path has too many parent prefixes (^)",
409 ACPI_FREE(external_path);
412 return_ACPI_STATUS(AE_NOT_FOUND);
416 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
417 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
418 "Search scope is [%4.4s], path has %u carat(s)\n",
419 acpi_ut_get_node_name
420 (this_node), num_carats));
425 * Determine the number of ACPI name segments in this pathname.
427 * The segment part consists of either:
428 * - A Null name segment (0)
429 * - A dual_name_prefix followed by two 4-byte name segments
430 * - A multi_name_prefix followed by a byte indicating the
431 * number of segments and the segments themselves.
432 * - A single 4-byte name segment
434 * Examine the name prefix opcode, if any, to determine the number of
440 * Null name after a root or parent prefixes. We already
441 * have the correct target node and there are no name segments.
444 type = this_node->type;
446 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
447 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
451 case AML_DUAL_NAME_PREFIX:
453 /* More than one name_seg, search rules do not apply */
455 search_parent_flag = ACPI_NS_NO_UPSEARCH;
457 /* Two segments, point to first name segment */
462 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
463 "Dual Pathname (2 segments, Flags=%X)\n",
467 case AML_MULTI_NAME_PREFIX:
469 /* More than one name_seg, search rules do not apply */
471 search_parent_flag = ACPI_NS_NO_UPSEARCH;
473 /* Extract segment count, point to first name segment */
476 num_segments = (u32) (u8) * path;
479 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
480 "Multi Pathname (%u Segments, Flags=%X)\n",
481 num_segments, flags));
486 * Not a Null name, no Dual or Multi prefix, hence there is
487 * only one name segment and Pathname is already pointing to it.
491 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
492 "Simple Pathname (1 segment, Flags=%X)\n",
497 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
501 * Search namespace for each segment of the name. Loop through and
502 * verify (or add to the namespace) each name segment.
504 * The object type is significant only at the last name
505 * segment. (We don't care about the types along the path, only
506 * the type of the final target object.)
508 this_search_type = ACPI_TYPE_ANY;
509 current_node = this_node;
511 while (num_segments && current_node) {
515 /* This is the last segment, enable typechecking */
517 this_search_type = type;
520 * Only allow automatic parent search (search rules) if the caller
521 * requested it AND we have a single, non-fully-qualified name_seg
523 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
524 (flags & ACPI_NS_SEARCH_PARENT)) {
525 local_flags |= ACPI_NS_SEARCH_PARENT;
528 /* Set error flag according to caller */
530 if (flags & ACPI_NS_ERROR_IF_FOUND) {
531 local_flags |= ACPI_NS_ERROR_IF_FOUND;
534 /* Set override flag according to caller */
536 if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
537 local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;
541 /* Handle opcodes that create a new name_seg via a full name_path */
543 local_interpreter_mode = interpreter_mode;
544 if ((flags & ACPI_NS_PREFIX_MUST_EXIST) && (num_segments > 0)) {
546 /* Every element of the path must exist (except for the final name_seg) */
548 local_interpreter_mode = ACPI_IMODE_EXECUTE;
551 /* Extract one ACPI name from the front of the pathname */
553 ACPI_MOVE_32_TO_32(&simple_name, path);
555 /* Try to find the single (4 character) ACPI name */
558 acpi_ns_search_and_enter(simple_name, walk_state,
560 local_interpreter_mode,
561 this_search_type, local_flags,
563 if (ACPI_FAILURE(status)) {
564 if (status == AE_NOT_FOUND) {
565 #if !defined ACPI_ASL_COMPILER /* Note: iASL reports this error by itself, not needed here */
566 if (flags & ACPI_NS_PREFIX_MUST_EXIST) {
567 acpi_os_printf(ACPI_MSG_BIOS_ERROR
568 "Object does not exist: %4.4s\n",
572 /* Name not found in ACPI namespace */
574 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
575 "Name [%4.4s] not found in scope [%4.4s] %p\n",
576 (char *)&simple_name,
577 (char *)¤t_node->name,
581 if ((status == AE_ALREADY_EXISTS) &&
582 (this_node->flags & ANOBJ_NODE_EARLY_INIT)) {
583 this_node->flags &= ~ANOBJ_NODE_EARLY_INIT;
588 #ifdef ACPI_ASL_COMPILER
590 * If this ACPI name already exists within the namespace as an
591 * external declaration, then mark the external as a conflicting
592 * declaration and proceed to process the current node as if it did
593 * not exist in the namespace. If this node is not processed as
594 * normal, then it could cause improper namespace resolution
595 * by failing to open a new scope.
597 if (acpi_gbl_disasm_flag &&
598 (status == AE_ALREADY_EXISTS) &&
599 ((this_node->flags & ANOBJ_IS_EXTERNAL) ||
601 && walk_state->opcode == AML_EXTERNAL_OP))) {
602 this_node->flags &= ~ANOBJ_IS_EXTERNAL;
603 this_node->type = (u8)this_search_type;
604 if (walk_state->opcode != AML_EXTERNAL_OP) {
605 acpi_dm_mark_external_conflict
612 *return_node = this_node;
613 return_ACPI_STATUS(status);
616 /* More segments to follow? */
618 if (num_segments > 0) {
620 * If we have an alias to an object that opens a scope (such as a
621 * device or processor), we need to dereference the alias here so
622 * that we can access any children of the original node (via the
623 * remaining segments).
625 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
626 if (!this_node->object) {
627 return_ACPI_STATUS(AE_NOT_EXIST);
630 if (acpi_ns_opens_scope
631 (((struct acpi_namespace_node *)
632 this_node->object)->type)) {
634 (struct acpi_namespace_node *)
640 /* Special handling for the last segment (num_segments == 0) */
644 * Sanity typecheck of the target object:
646 * If 1) This is the last segment (num_segments == 0)
647 * 2) And we are looking for a specific type
648 * (Not checking for TYPE_ANY)
649 * 3) Which is not an alias
650 * 4) Which is not a local type (TYPE_SCOPE)
651 * 5) And the type of target object is known (not TYPE_ANY)
652 * 6) And target object does not match what we are looking for
654 * Then we have a type mismatch. Just warn and ignore it.
656 if ((type_to_check_for != ACPI_TYPE_ANY) &&
657 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
658 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
659 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
660 && (this_node->type != ACPI_TYPE_ANY)
661 && (this_node->type != type_to_check_for)) {
663 /* Complain about a type mismatch */
665 ACPI_WARNING((AE_INFO,
666 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
667 ACPI_CAST_PTR(char, &simple_name),
668 acpi_ut_get_type_name(this_node->
670 acpi_ut_get_type_name
671 (type_to_check_for)));
675 * If this is the last name segment and we are not looking for a
676 * specific type, but the type of found object is known, use that
677 * type to (later) see if it opens a scope.
679 if (type == ACPI_TYPE_ANY) {
680 type = this_node->type;
684 /* Point to next name segment and make this node current */
686 path += ACPI_NAME_SIZE;
687 current_node = this_node;
690 /* Always check if we need to open a new scope */
692 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
694 * If entry is a type which opens a scope, push the new scope on the
697 if (acpi_ns_opens_scope(type)) {
699 acpi_ds_scope_stack_push(this_node, type,
701 if (ACPI_FAILURE(status)) {
702 return_ACPI_STATUS(status);
707 if (flags & ACPI_NS_EARLY_INIT) {
708 this_node->flags |= ANOBJ_NODE_EARLY_INIT;
712 *return_node = this_node;
713 return_ACPI_STATUS(AE_OK);