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 struct acpi_namespace_node
*prev_node
= NULL
;
40 union acpi_operand_object
*obj_desc
;
41 acpi_string val
= NULL
;
43 ACPI_FUNCTION_TRACE(ns_root_initialize
);
45 status
= acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE
);
46 if (ACPI_FAILURE(status
)) {
47 return_ACPI_STATUS(status
);
51 * The global root ptr is initially NULL, so a non-NULL value indicates
52 * that acpi_ns_root_initialize() has already been called; just return.
54 if (acpi_gbl_root_node
) {
60 * Tell the rest of the subsystem that the root is initialized
61 * (This is OK because the namespace is locked)
63 acpi_gbl_root_node
= &acpi_gbl_root_node_struct
;
65 /* Enter the predefined names in the name table */
67 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
68 "Entering predefined entries into namespace\n"));
71 * Create the initial (default) namespace.
72 * This namespace looks like something similar to this:
74 * ACPI Namespace (from Namespace Root):
75 * 0 _GPE Scope 00203160 00
76 * 0 _PR_ Scope 002031D0 00
77 * 0 _SB_ Device 00203240 00 Notify Object: 0020ADD8
78 * 0 _SI_ Scope 002032B0 00
79 * 0 _TZ_ Device 00203320 00
80 * 0 _REV Integer 00203390 00 = 0000000000000002
81 * 0 _OS_ String 00203488 00 Len 14 "Microsoft Windows NT"
82 * 0 _GL_ Mutex 00203580 00 Object 002035F0
83 * 0 _OSI Method 00203678 00 Args 1 Len 0000 Aml 00000000
85 for (init_val
= acpi_gbl_pre_defined_names
; init_val
->name
; init_val
++) {
88 /* _OSI is optional for now, will be permanent later */
90 if (!strcmp(init_val
->name
, "_OSI")
91 && !acpi_gbl_create_osi_method
) {
96 * Create, init, and link the new predefined name
97 * Note: No need to use acpi_ns_lookup here because all the
98 * predefined names are at the root level. It is much easier to
99 * just create and link the new node(s) here.
102 ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_namespace_node
));
104 status
= AE_NO_MEMORY
;
105 goto unlock_and_exit
;
108 ACPI_COPY_NAMESEG(new_node
->name
.ascii
, init_val
->name
);
109 new_node
->descriptor_type
= ACPI_DESC_TYPE_NAMED
;
110 new_node
->type
= init_val
->type
;
113 acpi_gbl_root_node_struct
.child
= new_node
;
115 prev_node
->peer
= new_node
;
118 new_node
->parent
= &acpi_gbl_root_node_struct
;
119 prev_node
= new_node
;
122 * Name entered successfully. If entry in pre_defined_names[] specifies
123 * an initial value, create the initial value.
126 status
= acpi_os_predefined_override(init_val
, &val
);
127 if (ACPI_FAILURE(status
)) {
129 "Could not override predefined %s",
138 * Entry requests an initial value, allocate a
142 acpi_ut_create_internal_object(init_val
->type
);
144 status
= AE_NO_MEMORY
;
145 goto unlock_and_exit
;
149 * Convert value string from table entry to
150 * internal representation. Only types actually
151 * used for initial values are implemented here.
153 switch (init_val
->type
) {
154 case ACPI_TYPE_METHOD
:
156 obj_desc
->method
.param_count
=
157 (u8
) ACPI_TO_INTEGER(val
);
158 obj_desc
->common
.flags
|= AOPOBJ_DATA_VALID
;
160 #if defined (ACPI_ASL_COMPILER)
162 /* Save the parameter count for the iASL compiler */
164 new_node
->value
= obj_desc
->method
.param_count
;
166 /* Mark this as a very SPECIAL method (_OSI) */
168 obj_desc
->method
.info_flags
=
169 ACPI_METHOD_INTERNAL_ONLY
;
170 obj_desc
->method
.dispatch
.implementation
=
171 acpi_ut_osi_implementation
;
175 case ACPI_TYPE_INTEGER
:
177 obj_desc
->integer
.value
= ACPI_TO_INTEGER(val
);
180 case ACPI_TYPE_STRING
:
182 /* Build an object around the static string */
184 obj_desc
->string
.length
= (u32
)strlen(val
);
185 obj_desc
->string
.pointer
= val
;
186 obj_desc
->common
.flags
|= AOPOBJ_STATIC_POINTER
;
189 case ACPI_TYPE_MUTEX
:
191 obj_desc
->mutex
.node
= new_node
;
192 obj_desc
->mutex
.sync_level
=
193 (u8
) (ACPI_TO_INTEGER(val
) - 1);
198 acpi_os_create_mutex(&obj_desc
->mutex
.
200 if (ACPI_FAILURE(status
)) {
201 acpi_ut_remove_reference(obj_desc
);
202 goto unlock_and_exit
;
205 /* Special case for ACPI Global Lock */
207 if (strcmp(init_val
->name
, "_GL_") == 0) {
208 acpi_gbl_global_lock_mutex
= obj_desc
;
210 /* Create additional counting semaphore for global lock */
213 acpi_os_create_semaphore(1, 0,
214 &acpi_gbl_global_lock_semaphore
);
215 if (ACPI_FAILURE(status
)) {
216 acpi_ut_remove_reference
218 goto unlock_and_exit
;
226 "Unsupported initial type value 0x%X",
228 acpi_ut_remove_reference(obj_desc
);
233 /* Store pointer to value descriptor in the Node */
235 status
= acpi_ns_attach_object(new_node
, obj_desc
,
236 obj_desc
->common
.type
);
238 /* Remove local reference to the object */
240 acpi_ut_remove_reference(obj_desc
);
245 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE
);
247 /* Save a handle to "_GPE", it is always present */
249 if (ACPI_SUCCESS(status
)) {
250 status
= acpi_ns_get_node(NULL
, "\\_GPE", ACPI_NS_NO_UPSEARCH
,
251 &acpi_gbl_fadt_gpe_device
);
254 return_ACPI_STATUS(status
);
257 /*******************************************************************************
259 * FUNCTION: acpi_ns_lookup
261 * PARAMETERS: scope_info - Current scope info block
262 * pathname - Search pathname, in internal format
263 * (as represented in the AML stream)
264 * type - Type associated with name
265 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
266 * flags - Flags describing the search restrictions
267 * walk_state - Current state of the walk
268 * return_node - Where the Node is placed (if found
269 * or created successfully)
273 * DESCRIPTION: Find or enter the passed name in the name space.
274 * Log an error if name not found in Exec mode.
276 * MUTEX: Assumes namespace is locked.
278 ******************************************************************************/
281 acpi_ns_lookup(union acpi_generic_state
*scope_info
,
283 acpi_object_type type
,
284 acpi_interpreter_mode interpreter_mode
,
286 struct acpi_walk_state
*walk_state
,
287 struct acpi_namespace_node
**return_node
)
290 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
;
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
;
302 acpi_interpreter_mode local_interpreter_mode
;
304 ACPI_FUNCTION_TRACE(ns_lookup
);
307 return_ACPI_STATUS(AE_BAD_PARAMETER
);
310 local_flags
= flags
&
311 ~(ACPI_NS_ERROR_IF_FOUND
| ACPI_NS_OVERRIDE_IF_FOUND
|
312 ACPI_NS_SEARCH_PARENT
);
313 *return_node
= ACPI_ENTRY_NOT_FOUND
;
314 acpi_gbl_ns_lookup_count
++;
316 if (!acpi_gbl_root_node
) {
317 return_ACPI_STATUS(AE_NO_NAMESPACE
);
320 /* Get the prefix scope. A null scope means use the root scope */
322 if ((!scope_info
) || (!scope_info
->scope
.node
)) {
323 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
324 "Null scope prefix, using root node (%p)\n",
325 acpi_gbl_root_node
));
327 prefix_node
= acpi_gbl_root_node
;
329 prefix_node
= scope_info
->scope
.node
;
330 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node
) !=
331 ACPI_DESC_TYPE_NAMED
) {
332 ACPI_ERROR((AE_INFO
, "%p is not a namespace node [%s]",
334 acpi_ut_get_descriptor_name(prefix_node
)));
335 return_ACPI_STATUS(AE_AML_INTERNAL
);
338 if (!(flags
& ACPI_NS_PREFIX_IS_SCOPE
)) {
340 * This node might not be a actual "scope" node (such as a
341 * Device/Method, etc.) It could be a Package or other object
342 * node. Backup up the tree to find the containing scope node.
344 while (!acpi_ns_opens_scope(prefix_node
->type
) &&
345 prefix_node
->type
!= ACPI_TYPE_ANY
) {
346 prefix_node
= prefix_node
->parent
;
351 /* Save type. TBD: may be no longer necessary */
353 type_to_check_for
= type
;
356 * Begin examination of the actual pathname
360 /* A Null name_path is allowed and refers to the root */
363 this_node
= acpi_gbl_root_node
;
366 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
367 "Null Pathname (Zero segments), Flags=%X\n",
371 * Name pointer is valid (and must be in internal name format)
373 * Check for scope prefixes:
375 * As represented in the AML stream, a namepath consists of an
376 * optional scope prefix followed by a name segment part.
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).
383 if (*path
== (u8
) AML_ROOT_PREFIX
) {
385 /* Pathname is fully qualified, start from the root */
387 this_node
= acpi_gbl_root_node
;
388 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
390 /* Point to name segment part */
394 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
395 "Path is absolute from root [%p]\n",
398 /* Pathname is relative to current scope, start there */
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
),
406 * Handle multiple Parent Prefixes (carat) by just getting
407 * the parent node for each prefix instance.
409 this_node
= prefix_node
;
411 while (*path
== (u8
) AML_PARENT_PREFIX
) {
413 /* Name is fully qualified, no search rules apply */
415 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
418 * Point past this prefix to the name segment
419 * part or the next Parent Prefix
423 /* Backup to the parent node */
426 this_node
= this_node
->parent
;
429 * Current scope has no parent scope. Externalize
430 * the internal path for error message.
433 acpi_ns_externalize_name
434 (ACPI_UINT32_MAX
, pathname
, NULL
,
436 if (ACPI_SUCCESS(status
)) {
438 "%s: Path has too many parent prefixes (^)",
441 ACPI_FREE(external_path
);
444 return_ACPI_STATUS(AE_NOT_FOUND
);
448 if (search_parent_flag
== ACPI_NS_NO_UPSEARCH
) {
449 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
450 "Search scope is [%4.4s], path has %u carat(s)\n",
451 acpi_ut_get_node_name
452 (this_node
), num_carats
));
457 * Determine the number of ACPI name segments in this pathname.
459 * The segment part consists of either:
460 * - A Null name segment (0)
461 * - A dual_name_prefix followed by two 4-byte name segments
462 * - A multi_name_prefix followed by a byte indicating the
463 * number of segments and the segments themselves.
464 * - A single 4-byte name segment
466 * Examine the name prefix opcode, if any, to determine the number of
472 * Null name after a root or parent prefixes. We already
473 * have the correct target node and there are no name segments.
476 type
= this_node
->type
;
478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
479 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
483 case AML_DUAL_NAME_PREFIX
:
485 /* More than one name_seg, search rules do not apply */
487 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
489 /* Two segments, point to first name segment */
494 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
495 "Dual Pathname (2 segments, Flags=%X)\n",
499 case AML_MULTI_NAME_PREFIX
:
501 /* More than one name_seg, search rules do not apply */
503 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
505 /* Extract segment count, point to first name segment */
508 num_segments
= (u32
) (u8
) * path
;
511 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
512 "Multi Pathname (%u Segments, Flags=%X)\n",
513 num_segments
, flags
));
518 * Not a Null name, no Dual or Multi prefix, hence there is
519 * only one name segment and Pathname is already pointing to it.
523 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
524 "Simple Pathname (1 segment, Flags=%X)\n",
529 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments
, path
));
533 * Search namespace for each segment of the name. Loop through and
534 * verify (or add to the namespace) each name segment.
536 * The object type is significant only at the last name
537 * segment. (We don't care about the types along the path, only
538 * the type of the final target object.)
540 this_search_type
= ACPI_TYPE_ANY
;
541 current_node
= this_node
;
543 while (num_segments
&& current_node
) {
547 /* This is the last segment, enable typechecking */
549 this_search_type
= type
;
552 * Only allow automatic parent search (search rules) if the caller
553 * requested it AND we have a single, non-fully-qualified name_seg
555 if ((search_parent_flag
!= ACPI_NS_NO_UPSEARCH
) &&
556 (flags
& ACPI_NS_SEARCH_PARENT
)) {
557 local_flags
|= ACPI_NS_SEARCH_PARENT
;
560 /* Set error flag according to caller */
562 if (flags
& ACPI_NS_ERROR_IF_FOUND
) {
563 local_flags
|= ACPI_NS_ERROR_IF_FOUND
;
566 /* Set override flag according to caller */
568 if (flags
& ACPI_NS_OVERRIDE_IF_FOUND
) {
569 local_flags
|= ACPI_NS_OVERRIDE_IF_FOUND
;
573 /* Handle opcodes that create a new name_seg via a full name_path */
575 local_interpreter_mode
= interpreter_mode
;
576 if ((flags
& ACPI_NS_PREFIX_MUST_EXIST
) && (num_segments
> 0)) {
578 /* Every element of the path must exist (except for the final name_seg) */
580 local_interpreter_mode
= ACPI_IMODE_EXECUTE
;
583 /* Extract one ACPI name from the front of the pathname */
585 ACPI_MOVE_32_TO_32(&simple_name
, path
);
587 /* Try to find the single (4 character) ACPI name */
590 acpi_ns_search_and_enter(simple_name
, walk_state
,
592 local_interpreter_mode
,
593 this_search_type
, local_flags
,
595 if (ACPI_FAILURE(status
)) {
596 if (status
== AE_NOT_FOUND
) {
597 #if !defined ACPI_ASL_COMPILER /* Note: iASL reports this error by itself, not needed here */
598 if (flags
& ACPI_NS_PREFIX_MUST_EXIST
) {
599 acpi_os_printf(ACPI_MSG_BIOS_ERROR
600 "Object does not exist: %4.4s\n",
601 (char *)&simple_name
);
604 /* Name not found in ACPI namespace */
606 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
607 "Name [%4.4s] not found in scope [%4.4s] %p\n",
608 (char *)&simple_name
,
609 (char *)¤t_node
->name
,
613 if ((status
== AE_ALREADY_EXISTS
) &&
614 (this_node
->flags
& ANOBJ_NODE_EARLY_INIT
)) {
615 this_node
->flags
&= ~ANOBJ_NODE_EARLY_INIT
;
620 #ifdef ACPI_ASL_COMPILER
622 * If this ACPI name already exists within the namespace as an
623 * external declaration, then mark the external as a conflicting
624 * declaration and proceed to process the current node as if it did
625 * not exist in the namespace. If this node is not processed as
626 * normal, then it could cause improper namespace resolution
627 * by failing to open a new scope.
629 if (acpi_gbl_disasm_flag
&&
630 (status
== AE_ALREADY_EXISTS
) &&
631 ((this_node
->flags
& ANOBJ_IS_EXTERNAL
) ||
633 && walk_state
->opcode
== AML_EXTERNAL_OP
))) {
634 this_node
->flags
&= ~ANOBJ_IS_EXTERNAL
;
635 this_node
->type
= (u8
)this_search_type
;
636 if (walk_state
->opcode
!= AML_EXTERNAL_OP
) {
637 acpi_dm_mark_external_conflict
644 *return_node
= this_node
;
645 return_ACPI_STATUS(status
);
648 /* More segments to follow? */
650 if (num_segments
> 0) {
652 * If we have an alias to an object that opens a scope (such as a
653 * device or processor), we need to dereference the alias here so
654 * that we can access any children of the original node (via the
655 * remaining segments).
657 if (this_node
->type
== ACPI_TYPE_LOCAL_ALIAS
) {
658 if (!this_node
->object
) {
659 return_ACPI_STATUS(AE_NOT_EXIST
);
662 if (acpi_ns_opens_scope
663 (((struct acpi_namespace_node
*)
664 this_node
->object
)->type
)) {
666 (struct acpi_namespace_node
*)
672 /* Special handling for the last segment (num_segments == 0) */
676 * Sanity typecheck of the target object:
678 * If 1) This is the last segment (num_segments == 0)
679 * 2) And we are looking for a specific type
680 * (Not checking for TYPE_ANY)
681 * 3) Which is not an alias
682 * 4) Which is not a local type (TYPE_SCOPE)
683 * 5) And the type of target object is known (not TYPE_ANY)
684 * 6) And target object does not match what we are looking for
686 * Then we have a type mismatch. Just warn and ignore it.
688 if ((type_to_check_for
!= ACPI_TYPE_ANY
) &&
689 (type_to_check_for
!= ACPI_TYPE_LOCAL_ALIAS
) &&
690 (type_to_check_for
!= ACPI_TYPE_LOCAL_METHOD_ALIAS
)
691 && (type_to_check_for
!= ACPI_TYPE_LOCAL_SCOPE
)
692 && (this_node
->type
!= ACPI_TYPE_ANY
)
693 && (this_node
->type
!= type_to_check_for
)) {
695 /* Complain about a type mismatch */
697 ACPI_WARNING((AE_INFO
,
698 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
699 ACPI_CAST_PTR(char, &simple_name
),
700 acpi_ut_get_type_name(this_node
->
702 acpi_ut_get_type_name
703 (type_to_check_for
)));
707 * If this is the last name segment and we are not looking for a
708 * specific type, but the type of found object is known, use that
709 * type to (later) see if it opens a scope.
711 if (type
== ACPI_TYPE_ANY
) {
712 type
= this_node
->type
;
716 /* Point to next name segment and make this node current */
718 path
+= ACPI_NAMESEG_SIZE
;
719 current_node
= this_node
;
722 /* Always check if we need to open a new scope */
724 if (!(flags
& ACPI_NS_DONT_OPEN_SCOPE
) && (walk_state
)) {
726 * If entry is a type which opens a scope, push the new scope on the
729 if (acpi_ns_opens_scope(type
)) {
731 acpi_ds_scope_stack_push(this_node
, type
,
733 if (ACPI_FAILURE(status
)) {
734 return_ACPI_STATUS(status
);
739 if (flags
& ACPI_NS_EARLY_INIT
) {
740 this_node
->flags
|= ANOBJ_NODE_EARLY_INIT
;
744 *return_node
= this_node
;
745 return_ACPI_STATUS(AE_OK
);