1 /*******************************************************************************
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
5 ******************************************************************************/
8 * Copyright (C) 2000 - 2008, 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>
45 #include <acpi/amlcode.h>
46 #include <acpi/acnamesp.h>
47 #include <acpi/acdispat.h>
49 #define _COMPONENT ACPI_NAMESPACE
50 ACPI_MODULE_NAME("nsaccess")
52 /*******************************************************************************
54 * FUNCTION: acpi_ns_root_initialize
60 * DESCRIPTION: Allocate and initialize the default root named objects
62 * MUTEX: Locks namespace for entire execution
64 ******************************************************************************/
65 acpi_status
acpi_ns_root_initialize(void)
68 const struct acpi_predefined_names
*init_val
= NULL
;
69 struct acpi_namespace_node
*new_node
;
70 union acpi_operand_object
*obj_desc
;
71 acpi_string val
= NULL
;
73 ACPI_FUNCTION_TRACE(ns_root_initialize
);
75 status
= acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE
);
76 if (ACPI_FAILURE(status
)) {
77 return_ACPI_STATUS(status
);
81 * The global root ptr is initially NULL, so a non-NULL value indicates
82 * that acpi_ns_root_initialize() has already been called; just return.
84 if (acpi_gbl_root_node
) {
90 * Tell the rest of the subsystem that the root is initialized
91 * (This is OK because the namespace is locked)
93 acpi_gbl_root_node
= &acpi_gbl_root_node_struct
;
95 /* Enter the pre-defined names in the name table */
97 ACPI_DEBUG_PRINT((ACPI_DB_INFO
,
98 "Entering predefined entries into namespace\n"));
100 for (init_val
= acpi_gbl_pre_defined_names
; init_val
->name
; init_val
++) {
102 /* _OSI is optional for now, will be permanent later */
104 if (!ACPI_STRCMP(init_val
->name
, "_OSI")
105 && !acpi_gbl_create_osi_method
) {
109 status
= acpi_ns_lookup(NULL
, init_val
->name
, init_val
->type
,
110 ACPI_IMODE_LOAD_PASS2
,
111 ACPI_NS_NO_UPSEARCH
, NULL
, &new_node
);
113 if (ACPI_FAILURE(status
) || (!new_node
)) { /* Must be on same line for code converter */
114 ACPI_EXCEPTION((AE_INFO
, status
,
115 "Could not create predefined name %s",
120 * Name entered successfully.
121 * If entry in pre_defined_names[] specifies an
122 * 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
:
154 obj_desc
->method
.param_count
=
155 (u8
) ACPI_TO_INTEGER(val
);
156 obj_desc
->common
.flags
|= AOPOBJ_DATA_VALID
;
158 #if defined (ACPI_ASL_COMPILER)
160 /* Save the parameter count for the i_aSL compiler */
162 new_node
->value
= obj_desc
->method
.param_count
;
164 /* Mark this as a very SPECIAL method */
166 obj_desc
->method
.method_flags
=
167 AML_METHOD_INTERNAL_ONLY
;
168 obj_desc
->method
.implementation
=
169 acpi_ut_osi_implementation
;
173 case ACPI_TYPE_INTEGER
:
175 obj_desc
->integer
.value
= ACPI_TO_INTEGER(val
);
178 case ACPI_TYPE_STRING
:
181 * Build an object around the static string
183 obj_desc
->string
.length
=
184 (u32
) ACPI_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 (ACPI_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 %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
,
239 /* Remove local reference to the object */
241 acpi_ut_remove_reference(obj_desc
);
246 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE
);
248 /* Save a handle to "_GPE", it is always present */
250 if (ACPI_SUCCESS(status
)) {
251 status
= acpi_ns_get_node(NULL
, "\\_GPE", ACPI_NS_NO_UPSEARCH
,
252 &acpi_gbl_fadt_gpe_device
);
255 return_ACPI_STATUS(status
);
258 /*******************************************************************************
260 * FUNCTION: acpi_ns_lookup
262 * PARAMETERS: scope_info - Current scope info block
263 * Pathname - Search pathname, in internal format
264 * (as represented in the AML stream)
265 * Type - Type associated with name
266 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
267 * Flags - Flags describing the search restrictions
268 * walk_state - Current state of the walk
269 * return_node - Where the Node is placed (if found
270 * or created successfully)
274 * DESCRIPTION: Find or enter the passed name in the name space.
275 * Log an error if name not found in Exec mode.
277 * MUTEX: Assumes namespace is locked.
279 ******************************************************************************/
282 acpi_ns_lookup(union acpi_generic_state
*scope_info
,
284 acpi_object_type type
,
285 acpi_interpreter_mode interpreter_mode
,
287 struct acpi_walk_state
*walk_state
,
288 struct acpi_namespace_node
**return_node
)
291 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
;
303 ACPI_FUNCTION_TRACE(ns_lookup
);
306 return_ACPI_STATUS(AE_BAD_PARAMETER
);
309 local_flags
= flags
& ~(ACPI_NS_ERROR_IF_FOUND
| 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
);
318 * Get the prefix scope.
319 * A null scope means use the root scope
321 if ((!scope_info
) || (!scope_info
->scope
.node
)) {
322 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
323 "Null scope prefix, using root node (%p)\n",
324 acpi_gbl_root_node
));
326 prefix_node
= acpi_gbl_root_node
;
328 prefix_node
= scope_info
->scope
.node
;
329 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node
) !=
330 ACPI_DESC_TYPE_NAMED
) {
331 ACPI_ERROR((AE_INFO
, "%p is not a namespace node [%s]",
333 acpi_ut_get_descriptor_name(prefix_node
)));
334 return_ACPI_STATUS(AE_AML_INTERNAL
);
337 if (!(flags
& ACPI_NS_PREFIX_IS_SCOPE
)) {
339 * This node might not be a actual "scope" node (such as a
340 * Device/Method, etc.) It could be a Package or other object node.
341 * Backup up the tree to find the containing scope node.
343 while (!acpi_ns_opens_scope(prefix_node
->type
) &&
344 prefix_node
->type
!= ACPI_TYPE_ANY
) {
346 acpi_ns_get_parent_node(prefix_node
);
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
;
417 * Point past this prefix to the name segment
418 * part or the next Parent Prefix
422 /* Backup to the parent node */
425 this_node
= acpi_ns_get_parent_node(this_node
);
428 /* Current scope has no parent scope */
431 "ACPI path has too many parent prefixes (^) - 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 %d 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 (%d 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
;
554 /* Extract one ACPI name from the front of the pathname */
556 ACPI_MOVE_32_TO_32(&simple_name
, path
);
558 /* Try to find the single (4 character) ACPI name */
561 acpi_ns_search_and_enter(simple_name
, walk_state
,
562 current_node
, interpreter_mode
,
563 this_search_type
, local_flags
,
565 if (ACPI_FAILURE(status
)) {
566 if (status
== AE_NOT_FOUND
) {
568 /* Name not found in ACPI namespace */
570 ACPI_DEBUG_PRINT((ACPI_DB_NAMES
,
571 "Name [%4.4s] not found in scope [%4.4s] %p\n",
572 (char *)&simple_name
,
573 (char *)¤t_node
->name
,
577 *return_node
= this_node
;
578 return_ACPI_STATUS(status
);
581 /* More segments to follow? */
583 if (num_segments
> 0) {
585 * If we have an alias to an object that opens a scope (such as a
586 * device or processor), we need to dereference the alias here so that
587 * we can access any children of the original node (via the remaining
590 if (this_node
->type
== ACPI_TYPE_LOCAL_ALIAS
) {
591 if (!this_node
->object
) {
592 return_ACPI_STATUS(AE_NOT_EXIST
);
595 if (acpi_ns_opens_scope
596 (((struct acpi_namespace_node
*)this_node
->
599 (struct acpi_namespace_node
*)
605 /* Special handling for the last segment (num_segments == 0) */
609 * Sanity typecheck of the target object:
611 * If 1) This is the last segment (num_segments == 0)
612 * 2) And we are looking for a specific type
613 * (Not checking for TYPE_ANY)
614 * 3) Which is not an alias
615 * 4) Which is not a local type (TYPE_SCOPE)
616 * 5) And the type of target object is known (not TYPE_ANY)
617 * 6) And target object does not match what we are looking for
619 * Then we have a type mismatch. Just warn and ignore it.
621 if ((type_to_check_for
!= ACPI_TYPE_ANY
) &&
622 (type_to_check_for
!= ACPI_TYPE_LOCAL_ALIAS
) &&
623 (type_to_check_for
!= ACPI_TYPE_LOCAL_METHOD_ALIAS
)
624 && (type_to_check_for
!= ACPI_TYPE_LOCAL_SCOPE
)
625 && (this_node
->type
!= ACPI_TYPE_ANY
)
626 && (this_node
->type
!= type_to_check_for
)) {
628 /* Complain about a type mismatch */
630 ACPI_WARNING((AE_INFO
,
631 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
632 ACPI_CAST_PTR(char, &simple_name
),
633 acpi_ut_get_type_name(this_node
->
635 acpi_ut_get_type_name
636 (type_to_check_for
)));
640 * If this is the last name segment and we are not looking for a
641 * specific type, but the type of found object is known, use that type
642 * to (later) see if it opens a scope.
644 if (type
== ACPI_TYPE_ANY
) {
645 type
= this_node
->type
;
649 /* Point to next name segment and make this node current */
651 path
+= ACPI_NAME_SIZE
;
652 current_node
= this_node
;
656 * Always check if we need to open a new scope
658 if (!(flags
& ACPI_NS_DONT_OPEN_SCOPE
) && (walk_state
)) {
660 * If entry is a type which opens a scope, push the new scope on the
663 if (acpi_ns_opens_scope(type
)) {
665 acpi_ds_scope_stack_push(this_node
, type
,
667 if (ACPI_FAILURE(status
)) {
668 return_ACPI_STATUS(status
);
673 *return_node
= this_node
;
674 return_ACPI_STATUS(AE_OK
);