1 /*******************************************************************************
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
5 ******************************************************************************/
8 * Copyright (C) 2000 - 2015, Intel Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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.
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
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41 * POSSIBILITY OF SUCH DAMAGES.
44 #include <acpi/acpi.h>
50 #define _COMPONENT ACPI_NAMESPACE
51 ACPI_MODULE_NAME("nsaccess")
53 /*******************************************************************************
55 * FUNCTION: acpi_ns_root_initialize
61 * DESCRIPTION: Allocate and initialize the default root named objects
63 * MUTEX: Locks namespace for entire execution
65 ******************************************************************************/
66 acpi_status
acpi_ns_root_initialize(void)
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
;
74 ACPI_FUNCTION_TRACE(ns_root_initialize
);
76 status
= acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE
);
77 if (ACPI_FAILURE(status
)) {
78 return_ACPI_STATUS(status
);
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.
85 if (acpi_gbl_root_node
) {
91 * Tell the rest of the subsystem that the root is initialized
92 * (This is OK because the namespace is locked)
94 acpi_gbl_root_node
= &acpi_gbl_root_node_struct
;
96 /* Enter the pre-defined names in the name table */
98 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
99 "Entering predefined entries into namespace\n"));
101 for (init_val
= acpi_gbl_pre_defined_names
; init_val
->name
; init_val
++) {
103 /* _OSI is optional for now, will be permanent later */
105 if (!strcmp(init_val
->name
, "_OSI")
106 && !acpi_gbl_create_osi_method
) {
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 if (ACPI_FAILURE(status
)) {
114 ACPI_EXCEPTION((AE_INFO
, status
,
115 "Could not create predefined name %s",
121 * Name entered successfully. If entry in pre_defined_names[] specifies
122 * an initial value, create the initial value.
125 status
= acpi_os_predefined_override(init_val
, &val
);
126 if (ACPI_FAILURE(status
)) {
128 "Could not override predefined %s",
137 * Entry requests an initial value, allocate a
141 acpi_ut_create_internal_object(init_val
->type
);
143 status
= AE_NO_MEMORY
;
144 goto unlock_and_exit
;
148 * Convert value string from table entry to
149 * internal representation. Only types actually
150 * used for initial values are implemented here.
152 switch (init_val
->type
) {
153 case ACPI_TYPE_METHOD
:
155 obj_desc
->method
.param_count
=
156 (u8
) ACPI_TO_INTEGER(val
);
157 obj_desc
->common
.flags
|= AOPOBJ_DATA_VALID
;
159 #if defined (ACPI_ASL_COMPILER)
161 /* Save the parameter count for the iASL compiler */
163 new_node
->value
= obj_desc
->method
.param_count
;
165 /* Mark this as a very SPECIAL method */
167 obj_desc
->method
.info_flags
=
168 ACPI_METHOD_INTERNAL_ONLY
;
169 obj_desc
->method
.dispatch
.implementation
=
170 acpi_ut_osi_implementation
;
174 case ACPI_TYPE_INTEGER
:
176 obj_desc
->integer
.value
= ACPI_TO_INTEGER(val
);
179 case ACPI_TYPE_STRING
:
181 /* Build an object around the static string */
183 obj_desc
->string
.length
= (u32
)strlen(val
);
184 obj_desc
->string
.pointer
= val
;
185 obj_desc
->common
.flags
|= AOPOBJ_STATIC_POINTER
;
188 case ACPI_TYPE_MUTEX
:
190 obj_desc
->mutex
.node
= new_node
;
191 obj_desc
->mutex
.sync_level
=
192 (u8
) (ACPI_TO_INTEGER(val
) - 1);
197 acpi_os_create_mutex(&obj_desc
->mutex
.
199 if (ACPI_FAILURE(status
)) {
200 acpi_ut_remove_reference(obj_desc
);
201 goto unlock_and_exit
;
204 /* Special case for ACPI Global Lock */
206 if (strcmp(init_val
->name
, "_GL_") == 0) {
207 acpi_gbl_global_lock_mutex
= obj_desc
;
209 /* Create additional counting semaphore for global lock */
212 acpi_os_create_semaphore(1, 0,
213 &acpi_gbl_global_lock_semaphore
);
214 if (ACPI_FAILURE(status
)) {
215 acpi_ut_remove_reference
217 goto unlock_and_exit
;
225 "Unsupported initial type value 0x%X",
227 acpi_ut_remove_reference(obj_desc
);
232 /* Store pointer to value descriptor in the Node */
234 status
= acpi_ns_attach_object(new_node
, obj_desc
,
235 obj_desc
->common
.type
);
237 /* Remove local reference to the object */
239 acpi_ut_remove_reference(obj_desc
);
244 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE
);
246 /* Save a handle to "_GPE", it is always present */
248 if (ACPI_SUCCESS(status
)) {
249 status
= acpi_ns_get_node(NULL
, "\\_GPE", ACPI_NS_NO_UPSEARCH
,
250 &acpi_gbl_fadt_gpe_device
);
253 return_ACPI_STATUS(status
);
256 /*******************************************************************************
258 * FUNCTION: acpi_ns_lookup
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)
272 * DESCRIPTION: Find or enter the passed name in the name space.
273 * Log an error if name not found in Exec mode.
275 * MUTEX: Assumes namespace is locked.
277 ******************************************************************************/
280 acpi_ns_lookup(union acpi_generic_state
*scope_info
,
282 acpi_object_type type
,
283 acpi_interpreter_mode interpreter_mode
,
285 struct acpi_walk_state
*walk_state
,
286 struct acpi_namespace_node
**return_node
)
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
;
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
;
301 ACPI_FUNCTION_TRACE(ns_lookup
);
304 return_ACPI_STATUS(AE_BAD_PARAMETER
);
307 local_flags
= flags
&
308 ~(ACPI_NS_ERROR_IF_FOUND
| ACPI_NS_OVERRIDE_IF_FOUND
|
309 ACPI_NS_SEARCH_PARENT
);
310 *return_node
= ACPI_ENTRY_NOT_FOUND
;
311 acpi_gbl_ns_lookup_count
++;
313 if (!acpi_gbl_root_node
) {
314 return_ACPI_STATUS(AE_NO_NAMESPACE
);
317 /* Get the prefix scope. A null scope means use the root scope */
319 if ((!scope_info
) || (!scope_info
->scope
.node
)) {
320 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
321 "Null scope prefix, using root node (%p)\n",
322 acpi_gbl_root_node
));
324 prefix_node
= acpi_gbl_root_node
;
326 prefix_node
= scope_info
->scope
.node
;
327 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node
) !=
328 ACPI_DESC_TYPE_NAMED
) {
329 ACPI_ERROR((AE_INFO
, "%p is not a namespace node [%s]",
331 acpi_ut_get_descriptor_name(prefix_node
)));
332 return_ACPI_STATUS(AE_AML_INTERNAL
);
335 if (!(flags
& ACPI_NS_PREFIX_IS_SCOPE
)) {
337 * This node might not be a actual "scope" node (such as a
338 * Device/Method, etc.) It could be a Package or other object
339 * node. Backup up the tree to find the containing scope node.
341 while (!acpi_ns_opens_scope(prefix_node
->type
) &&
342 prefix_node
->type
!= ACPI_TYPE_ANY
) {
343 prefix_node
= prefix_node
->parent
;
348 /* Save type. TBD: may be no longer necessary */
350 type_to_check_for
= type
;
353 * Begin examination of the actual pathname
357 /* A Null name_path is allowed and refers to the root */
360 this_node
= acpi_gbl_root_node
;
363 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
364 "Null Pathname (Zero segments), Flags=%X\n",
368 * Name pointer is valid (and must be in internal name format)
370 * Check for scope prefixes:
372 * As represented in the AML stream, a namepath consists of an
373 * optional scope prefix followed by a name segment part.
375 * If present, the scope prefix is either a Root Prefix (in
376 * which case the name is fully qualified), or one or more
377 * Parent Prefixes (in which case the name's scope is relative
378 * to the current scope).
380 if (*path
== (u8
) AML_ROOT_PREFIX
) {
382 /* Pathname is fully qualified, start from the root */
384 this_node
= acpi_gbl_root_node
;
385 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
387 /* Point to name segment part */
391 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
392 "Path is absolute from root [%p]\n",
395 /* Pathname is relative to current scope, start there */
397 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
398 "Searching relative to prefix scope [%4.4s] (%p)\n",
399 acpi_ut_get_node_name(prefix_node
),
403 * Handle multiple Parent Prefixes (carat) by just getting
404 * the parent node for each prefix instance.
406 this_node
= prefix_node
;
408 while (*path
== (u8
) AML_PARENT_PREFIX
) {
410 /* Name is fully qualified, no search rules apply */
412 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
415 * Point past this prefix to the name segment
416 * part or the next Parent Prefix
420 /* Backup to the parent node */
423 this_node
= this_node
->parent
;
426 /* Current scope has no parent scope */
429 "%s: Path has too many parent prefixes (^) "
430 "- reached beyond root node",
432 return_ACPI_STATUS(AE_NOT_FOUND
);
436 if (search_parent_flag
== ACPI_NS_NO_UPSEARCH
) {
437 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
438 "Search scope is [%4.4s], path has %u carat(s)\n",
439 acpi_ut_get_node_name
440 (this_node
), num_carats
));
445 * Determine the number of ACPI name segments in this pathname.
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
454 * Examine the name prefix opcode, if any, to determine the number of
460 * Null name after a root or parent prefixes. We already
461 * have the correct target node and there are no name segments.
464 type
= this_node
->type
;
466 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
467 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
471 case AML_DUAL_NAME_PREFIX
:
473 /* More than one name_seg, search rules do not apply */
475 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
477 /* Two segments, point to first name segment */
482 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
483 "Dual Pathname (2 segments, Flags=%X)\n",
487 case AML_MULTI_NAME_PREFIX_OP
:
489 /* More than one name_seg, search rules do not apply */
491 search_parent_flag
= ACPI_NS_NO_UPSEARCH
;
493 /* Extract segment count, point to first name segment */
496 num_segments
= (u32
) (u8
) * path
;
499 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
500 "Multi Pathname (%u Segments, Flags=%X)\n",
501 num_segments
, flags
));
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.
511 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
512 "Simple Pathname (1 segment, Flags=%X)\n",
517 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments
, path
));
521 * Search namespace for each segment of the name. Loop through and
522 * verify (or add to the namespace) each name segment.
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.)
528 this_search_type
= ACPI_TYPE_ANY
;
529 current_node
= this_node
;
530 while (num_segments
&& current_node
) {
534 /* This is the last segment, enable typechecking */
536 this_search_type
= type
;
539 * Only allow automatic parent search (search rules) if the caller
540 * requested it AND we have a single, non-fully-qualified name_seg
542 if ((search_parent_flag
!= ACPI_NS_NO_UPSEARCH
) &&
543 (flags
& ACPI_NS_SEARCH_PARENT
)) {
544 local_flags
|= ACPI_NS_SEARCH_PARENT
;
547 /* Set error flag according to caller */
549 if (flags
& ACPI_NS_ERROR_IF_FOUND
) {
550 local_flags
|= ACPI_NS_ERROR_IF_FOUND
;
553 /* Set override flag according to caller */
555 if (flags
& ACPI_NS_OVERRIDE_IF_FOUND
) {
556 local_flags
|= ACPI_NS_OVERRIDE_IF_FOUND
;
560 /* Extract one ACPI name from the front of the pathname */
562 ACPI_MOVE_32_TO_32(&simple_name
, path
);
564 /* Try to find the single (4 character) ACPI name */
567 acpi_ns_search_and_enter(simple_name
, walk_state
,
568 current_node
, interpreter_mode
,
569 this_search_type
, local_flags
,
571 if (ACPI_FAILURE(status
)) {
572 if (status
== AE_NOT_FOUND
) {
574 /* Name not found in ACPI namespace */
576 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
577 "Name [%4.4s] not found in scope [%4.4s] %p\n",
578 (char *)&simple_name
,
579 (char *)¤t_node
->name
,
583 *return_node
= this_node
;
584 return_ACPI_STATUS(status
);
587 /* More segments to follow? */
589 if (num_segments
> 0) {
591 * If we have an alias to an object that opens a scope (such as a
592 * device or processor), we need to dereference the alias here so
593 * that we can access any children of the original node (via the
594 * remaining segments).
596 if (this_node
->type
== ACPI_TYPE_LOCAL_ALIAS
) {
597 if (!this_node
->object
) {
598 return_ACPI_STATUS(AE_NOT_EXIST
);
601 if (acpi_ns_opens_scope
602 (((struct acpi_namespace_node
*)
603 this_node
->object
)->type
)) {
605 (struct acpi_namespace_node
*)
611 /* Special handling for the last segment (num_segments == 0) */
615 * Sanity typecheck of the target object:
617 * If 1) This is the last segment (num_segments == 0)
618 * 2) And we are looking for a specific type
619 * (Not checking for TYPE_ANY)
620 * 3) Which is not an alias
621 * 4) Which is not a local type (TYPE_SCOPE)
622 * 5) And the type of target object is known (not TYPE_ANY)
623 * 6) And target object does not match what we are looking for
625 * Then we have a type mismatch. Just warn and ignore it.
627 if ((type_to_check_for
!= ACPI_TYPE_ANY
) &&
628 (type_to_check_for
!= ACPI_TYPE_LOCAL_ALIAS
) &&
629 (type_to_check_for
!= ACPI_TYPE_LOCAL_METHOD_ALIAS
)
630 && (type_to_check_for
!= ACPI_TYPE_LOCAL_SCOPE
)
631 && (this_node
->type
!= ACPI_TYPE_ANY
)
632 && (this_node
->type
!= type_to_check_for
)) {
634 /* Complain about a type mismatch */
636 ACPI_WARNING((AE_INFO
,
637 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
638 ACPI_CAST_PTR(char, &simple_name
),
639 acpi_ut_get_type_name(this_node
->
641 acpi_ut_get_type_name
642 (type_to_check_for
)));
646 * If this is the last name segment and we are not looking for a
647 * specific type, but the type of found object is known, use that
648 * type to (later) see if it opens a scope.
650 if (type
== ACPI_TYPE_ANY
) {
651 type
= this_node
->type
;
655 /* Point to next name segment and make this node current */
657 path
+= ACPI_NAME_SIZE
;
658 current_node
= this_node
;
661 /* Always check if we need to open a new scope */
663 if (!(flags
& ACPI_NS_DONT_OPEN_SCOPE
) && (walk_state
)) {
665 * If entry is a type which opens a scope, push the new scope on the
668 if (acpi_ns_opens_scope(type
)) {
670 acpi_ds_scope_stack_push(this_node
, type
,
672 if (ACPI_FAILURE(status
)) {
673 return_ACPI_STATUS(status
);
678 *return_node
= this_node
;
679 return_ACPI_STATUS(AE_OK
);