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
;
271 ACPI_FUNCTION_TRACE(ns_lookup
);
274 return_ACPI_STATUS(AE_BAD_PARAMETER
);
277 local_flags
= flags
&
278 ~(ACPI_NS_ERROR_IF_FOUND
| ACPI_NS_OVERRIDE_IF_FOUND
|
279 ACPI_NS_SEARCH_PARENT
);
280 *return_node
= ACPI_ENTRY_NOT_FOUND
;
281 acpi_gbl_ns_lookup_count
++;
283 if (!acpi_gbl_root_node
) {
284 return_ACPI_STATUS(AE_NO_NAMESPACE
);
287 /* Get the prefix scope. A null scope means use the root scope */
289 if ((!scope_info
) || (!scope_info
->scope
.node
)) {
290 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
291 "Null scope prefix, using root node (%p)\n",
292 acpi_gbl_root_node
));
294 prefix_node
= acpi_gbl_root_node
;
296 prefix_node
= scope_info
->scope
.node
;
297 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node
) !=
298 ACPI_DESC_TYPE_NAMED
) {
299 ACPI_ERROR((AE_INFO
, "%p is not a namespace node [%s]",
301 acpi_ut_get_descriptor_name(prefix_node
)));
302 return_ACPI_STATUS(AE_AML_INTERNAL
);
305 if (!(flags
& ACPI_NS_PREFIX_IS_SCOPE
)) {
307 * This node might not be a actual "scope" node (such as a
308 * Device/Method, etc.) It could be a Package or other object
309 * node. Backup up the tree to find the containing scope node.
311 while (!acpi_ns_opens_scope(prefix_node
->type
) &&
312 prefix_node
->type
!= ACPI_TYPE_ANY
) {
313 prefix_node
= prefix_node
->parent
;
318 /* Save type. TBD: may be no longer necessary */
320 type_to_check_for
= type
;
323 * Begin examination of the actual pathname
327 /* A Null name_path is allowed and refers to the root */
330 this_node
= acpi_gbl_root_node
;
333 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
334 "Null Pathname (Zero segments), Flags=%X\n",
338 * Name pointer is valid (and must be in internal name format)
340 * Check for scope prefixes:
342 * As represented in the AML stream, a namepath consists of an
343 * optional scope prefix followed by a name segment part.
345 * If present, the scope prefix is either a Root Prefix (in
346 * which case the name is fully qualified), or one or more
347 * Parent Prefixes (in which case the name's scope is relative
348 * to the current scope).
350 if (*path
== (u8
) AML_ROOT_PREFIX
) {
352 /* Pathname is fully qualified, start from the root */
354 this_node
= acpi_gbl_root_node
;
355 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
357 /* Point to name segment part */
361 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
362 "Path is absolute from root [%p]\n",
365 /* Pathname is relative to current scope, start there */
367 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
368 "Searching relative to prefix scope [%4.4s] (%p)\n",
369 acpi_ut_get_node_name(prefix_node
),
373 * Handle multiple Parent Prefixes (carat) by just getting
374 * the parent node for each prefix instance.
376 this_node
= prefix_node
;
378 while (*path
== (u8
) AML_PARENT_PREFIX
) {
380 /* Name is fully qualified, no search rules apply */
382 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
385 * Point past this prefix to the name segment
386 * part or the next Parent Prefix
390 /* Backup to the parent node */
393 this_node
= this_node
->parent
;
396 * Current scope has no parent scope. Externalize
397 * the internal path for error message.
400 acpi_ns_externalize_name
401 (ACPI_UINT32_MAX
, pathname
, NULL
,
403 if (ACPI_SUCCESS(status
)) {
405 "%s: Path has too many parent prefixes (^)",
408 ACPI_FREE(external_path
);
411 return_ACPI_STATUS(AE_NOT_FOUND
);
415 if (search_parent_flag
== ACPI_NS_NO_UPSEARCH
) {
416 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
417 "Search scope is [%4.4s], path has %u carat(s)\n",
418 acpi_ut_get_node_name
419 (this_node
), num_carats
));
424 * Determine the number of ACPI name segments in this pathname.
426 * The segment part consists of either:
427 * - A Null name segment (0)
428 * - A dual_name_prefix followed by two 4-byte name segments
429 * - A multi_name_prefix followed by a byte indicating the
430 * number of segments and the segments themselves.
431 * - A single 4-byte name segment
433 * Examine the name prefix opcode, if any, to determine the number of
439 * Null name after a root or parent prefixes. We already
440 * have the correct target node and there are no name segments.
443 type
= this_node
->type
;
445 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
446 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
450 case AML_DUAL_NAME_PREFIX
:
452 /* More than one name_seg, search rules do not apply */
454 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
456 /* Two segments, point to first name segment */
461 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
462 "Dual Pathname (2 segments, Flags=%X)\n",
466 case AML_MULTI_NAME_PREFIX
:
468 /* More than one name_seg, search rules do not apply */
470 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
472 /* Extract segment count, point to first name segment */
475 num_segments
= (u32
) (u8
) * path
;
478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
479 "Multi Pathname (%u Segments, Flags=%X)\n",
480 num_segments
, flags
));
485 * Not a Null name, no Dual or Multi prefix, hence there is
486 * only one name segment and Pathname is already pointing to it.
490 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
491 "Simple Pathname (1 segment, Flags=%X)\n",
496 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments
, path
));
500 * Search namespace for each segment of the name. Loop through and
501 * verify (or add to the namespace) each name segment.
503 * The object type is significant only at the last name
504 * segment. (We don't care about the types along the path, only
505 * the type of the final target object.)
507 this_search_type
= ACPI_TYPE_ANY
;
508 current_node
= this_node
;
509 while (num_segments
&& current_node
) {
513 /* This is the last segment, enable typechecking */
515 this_search_type
= type
;
518 * Only allow automatic parent search (search rules) if the caller
519 * requested it AND we have a single, non-fully-qualified name_seg
521 if ((search_parent_flag
!= ACPI_NS_NO_UPSEARCH
) &&
522 (flags
& ACPI_NS_SEARCH_PARENT
)) {
523 local_flags
|= ACPI_NS_SEARCH_PARENT
;
526 /* Set error flag according to caller */
528 if (flags
& ACPI_NS_ERROR_IF_FOUND
) {
529 local_flags
|= ACPI_NS_ERROR_IF_FOUND
;
532 /* Set override flag according to caller */
534 if (flags
& ACPI_NS_OVERRIDE_IF_FOUND
) {
535 local_flags
|= ACPI_NS_OVERRIDE_IF_FOUND
;
539 /* Extract one ACPI name from the front of the pathname */
541 ACPI_MOVE_32_TO_32(&simple_name
, path
);
543 /* Try to find the single (4 character) ACPI name */
546 acpi_ns_search_and_enter(simple_name
, walk_state
,
547 current_node
, interpreter_mode
,
548 this_search_type
, local_flags
,
550 if (ACPI_FAILURE(status
)) {
551 if (status
== AE_NOT_FOUND
) {
553 /* Name not found in ACPI namespace */
555 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
556 "Name [%4.4s] not found in scope [%4.4s] %p\n",
557 (char *)&simple_name
,
558 (char *)¤t_node
->name
,
562 if ((status
== AE_ALREADY_EXISTS
) &&
563 (this_node
->flags
& ANOBJ_NODE_EARLY_INIT
)) {
564 this_node
->flags
&= ~ANOBJ_NODE_EARLY_INIT
;
569 #ifdef ACPI_ASL_COMPILER
571 * If this ACPI name already exists within the namespace as an
572 * external declaration, then mark the external as a conflicting
573 * declaration and proceed to process the current node as if it did
574 * not exist in the namespace. If this node is not processed as
575 * normal, then it could cause improper namespace resolution
576 * by failing to open a new scope.
578 if (acpi_gbl_disasm_flag
&&
579 (status
== AE_ALREADY_EXISTS
) &&
580 ((this_node
->flags
& ANOBJ_IS_EXTERNAL
) ||
582 && walk_state
->opcode
== AML_EXTERNAL_OP
))) {
583 this_node
->flags
&= ~ANOBJ_IS_EXTERNAL
;
584 this_node
->type
= (u8
)this_search_type
;
585 if (walk_state
->opcode
!= AML_EXTERNAL_OP
) {
586 acpi_dm_mark_external_conflict
593 *return_node
= this_node
;
594 return_ACPI_STATUS(status
);
597 /* More segments to follow? */
599 if (num_segments
> 0) {
601 * If we have an alias to an object that opens a scope (such as a
602 * device or processor), we need to dereference the alias here so
603 * that we can access any children of the original node (via the
604 * remaining segments).
606 if (this_node
->type
== ACPI_TYPE_LOCAL_ALIAS
) {
607 if (!this_node
->object
) {
608 return_ACPI_STATUS(AE_NOT_EXIST
);
611 if (acpi_ns_opens_scope
612 (((struct acpi_namespace_node
*)
613 this_node
->object
)->type
)) {
615 (struct acpi_namespace_node
*)
621 /* Special handling for the last segment (num_segments == 0) */
625 * Sanity typecheck of the target object:
627 * If 1) This is the last segment (num_segments == 0)
628 * 2) And we are looking for a specific type
629 * (Not checking for TYPE_ANY)
630 * 3) Which is not an alias
631 * 4) Which is not a local type (TYPE_SCOPE)
632 * 5) And the type of target object is known (not TYPE_ANY)
633 * 6) And target object does not match what we are looking for
635 * Then we have a type mismatch. Just warn and ignore it.
637 if ((type_to_check_for
!= ACPI_TYPE_ANY
) &&
638 (type_to_check_for
!= ACPI_TYPE_LOCAL_ALIAS
) &&
639 (type_to_check_for
!= ACPI_TYPE_LOCAL_METHOD_ALIAS
)
640 && (type_to_check_for
!= ACPI_TYPE_LOCAL_SCOPE
)
641 && (this_node
->type
!= ACPI_TYPE_ANY
)
642 && (this_node
->type
!= type_to_check_for
)) {
644 /* Complain about a type mismatch */
646 ACPI_WARNING((AE_INFO
,
647 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
648 ACPI_CAST_PTR(char, &simple_name
),
649 acpi_ut_get_type_name(this_node
->
651 acpi_ut_get_type_name
652 (type_to_check_for
)));
656 * If this is the last name segment and we are not looking for a
657 * specific type, but the type of found object is known, use that
658 * type to (later) see if it opens a scope.
660 if (type
== ACPI_TYPE_ANY
) {
661 type
= this_node
->type
;
665 /* Point to next name segment and make this node current */
667 path
+= ACPI_NAME_SIZE
;
668 current_node
= this_node
;
671 /* Always check if we need to open a new scope */
673 if (!(flags
& ACPI_NS_DONT_OPEN_SCOPE
) && (walk_state
)) {
675 * If entry is a type which opens a scope, push the new scope on the
678 if (acpi_ns_opens_scope(type
)) {
680 acpi_ds_scope_stack_push(this_node
, type
,
682 if (ACPI_FAILURE(status
)) {
683 return_ACPI_STATUS(status
);
688 if (flags
& ACPI_NS_EARLY_INIT
) {
689 this_node
->flags
|= ANOBJ_NODE_EARLY_INIT
;
693 *return_node
= this_node
;
694 return_ACPI_STATUS(AE_OK
);