1 /*******************************************************************************
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
5 ******************************************************************************/
8 * Copyright (C) 2000 - 2006, R. Byron Moore
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
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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;
169 #ifndef ACPI_DUMP_APP
170 obj_desc->method.implementation =
171 acpi_ut_osi_implementation;
176 case ACPI_TYPE_INTEGER:
178 obj_desc->integer.value = ACPI_TO_INTEGER(val);
181 case ACPI_TYPE_STRING:
184 * Build an object around the static string
186 obj_desc->string.length =
187 (u32) ACPI_STRLEN(val);
188 obj_desc->string.pointer = val;
189 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
192 case ACPI_TYPE_MUTEX:
194 obj_desc->mutex.node = new_node;
195 obj_desc->mutex.sync_level =
196 (u8) (ACPI_TO_INTEGER(val) - 1);
198 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
200 * Create a counting semaphore for the
204 acpi_os_create_semaphore
205 (ACPI_NO_UNIT_LIMIT, 1,
206 &obj_desc->mutex.semaphore);
207 if (ACPI_FAILURE(status)) {
208 acpi_ut_remove_reference
210 goto unlock_and_exit;
214 * We just created the mutex for the
215 * global lock, save it
217 acpi_gbl_global_lock_semaphore =
218 obj_desc->mutex.semaphore;
222 status = acpi_os_create_semaphore(1, 1,
226 if (ACPI_FAILURE(status)) {
227 acpi_ut_remove_reference
229 goto unlock_and_exit;
237 "Unsupported initial type value %X",
239 acpi_ut_remove_reference(obj_desc);
244 /* Store pointer to value descriptor in the Node */
246 status = acpi_ns_attach_object(new_node, obj_desc,
250 /* Remove local reference to the object */
252 acpi_ut_remove_reference(obj_desc);
257 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
259 /* Save a handle to "_GPE", it is always present */
261 if (ACPI_SUCCESS(status)) {
262 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
263 &acpi_gbl_fadt_gpe_device);
266 return_ACPI_STATUS(status);
269 /*******************************************************************************
271 * FUNCTION: acpi_ns_lookup
273 * PARAMETERS: scope_info - Current scope info block
274 * Pathname - Search pathname, in internal format
275 * (as represented in the AML stream)
276 * Type - Type associated with name
277 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
278 * Flags - Flags describing the search restrictions
279 * walk_state - Current state of the walk
280 * return_node - Where the Node is placed (if found
281 * or created successfully)
285 * DESCRIPTION: Find or enter the passed name in the name space.
286 * Log an error if name not found in Exec mode.
288 * MUTEX: Assumes namespace is locked.
290 ******************************************************************************/
293 acpi_ns_lookup(union acpi_generic_state *scope_info,
295 acpi_object_type type,
296 acpi_interpreter_mode interpreter_mode,
298 struct acpi_walk_state *walk_state,
299 struct acpi_namespace_node **return_node)
302 char *path = pathname;
303 struct acpi_namespace_node *prefix_node;
304 struct acpi_namespace_node *current_node = NULL;
305 struct acpi_namespace_node *this_node = NULL;
308 acpi_name simple_name;
309 acpi_object_type type_to_check_for;
310 acpi_object_type this_search_type;
311 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
314 ACPI_FUNCTION_TRACE(ns_lookup);
317 return_ACPI_STATUS(AE_BAD_PARAMETER);
320 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
321 *return_node = ACPI_ENTRY_NOT_FOUND;
322 acpi_gbl_ns_lookup_count++;
324 if (!acpi_gbl_root_node) {
325 return_ACPI_STATUS(AE_NO_NAMESPACE);
329 * Get the prefix scope.
330 * A null scope means use the root scope
332 if ((!scope_info) || (!scope_info->scope.node)) {
333 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
334 "Null scope prefix, using root node (%p)\n",
335 acpi_gbl_root_node));
337 prefix_node = acpi_gbl_root_node;
339 prefix_node = scope_info->scope.node;
340 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
341 ACPI_DESC_TYPE_NAMED) {
342 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
344 acpi_ut_get_descriptor_name(prefix_node)));
345 return_ACPI_STATUS(AE_AML_INTERNAL);
348 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
350 * This node might not be a actual "scope" node (such as a
351 * Device/Method, etc.) It could be a Package or other object node.
352 * Backup up the tree to find the containing scope node.
354 while (!acpi_ns_opens_scope(prefix_node->type) &&
355 prefix_node->type != ACPI_TYPE_ANY) {
357 acpi_ns_get_parent_node(prefix_node);
362 /* Save type TBD: may be no longer necessary */
364 type_to_check_for = type;
367 * Begin examination of the actual pathname
371 /* A Null name_path is allowed and refers to the root */
374 this_node = acpi_gbl_root_node;
377 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
378 "Null Pathname (Zero segments), Flags=%X\n",
382 * Name pointer is valid (and must be in internal name format)
384 * Check for scope prefixes:
386 * As represented in the AML stream, a namepath consists of an
387 * optional scope prefix followed by a name segment part.
389 * If present, the scope prefix is either a Root Prefix (in
390 * which case the name is fully qualified), or one or more
391 * Parent Prefixes (in which case the name's scope is relative
392 * to the current scope).
394 if (*path == (u8) AML_ROOT_PREFIX) {
396 /* Pathname is fully qualified, start from the root */
398 this_node = acpi_gbl_root_node;
399 search_parent_flag = ACPI_NS_NO_UPSEARCH;
401 /* Point to name segment part */
405 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
406 "Path is absolute from root [%p]\n",
409 /* Pathname is relative to current scope, start there */
411 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
412 "Searching relative to prefix scope [%4.4s] (%p)\n",
413 acpi_ut_get_node_name(prefix_node),
417 * Handle multiple Parent Prefixes (carat) by just getting
418 * the parent node for each prefix instance.
420 this_node = prefix_node;
422 while (*path == (u8) AML_PARENT_PREFIX) {
424 /* Name is fully qualified, no search rules apply */
426 search_parent_flag = ACPI_NS_NO_UPSEARCH;
428 * Point past this prefix to the name segment
429 * part or the next Parent Prefix
433 /* Backup to the parent node */
436 this_node = acpi_ns_get_parent_node(this_node);
439 /* Current scope has no parent scope */
442 "ACPI path has too many parent prefixes (^) - reached beyond root node"));
443 return_ACPI_STATUS(AE_NOT_FOUND);
447 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
448 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
449 "Search scope is [%4.4s], path has %d carat(s)\n",
450 acpi_ut_get_node_name
451 (this_node), num_carats));
456 * Determine the number of ACPI name segments in this pathname.
458 * The segment part consists of either:
459 * - A Null name segment (0)
460 * - A dual_name_prefix followed by two 4-byte name segments
461 * - A multi_name_prefix followed by a byte indicating the
462 * number of segments and the segments themselves.
463 * - A single 4-byte name segment
465 * Examine the name prefix opcode, if any, to determine the number of
471 * Null name after a root or parent prefixes. We already
472 * have the correct target node and there are no name segments.
475 type = this_node->type;
477 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
478 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
482 case AML_DUAL_NAME_PREFIX:
484 /* More than one name_seg, search rules do not apply */
486 search_parent_flag = ACPI_NS_NO_UPSEARCH;
488 /* Two segments, point to first name segment */
493 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
494 "Dual Pathname (2 segments, Flags=%X)\n",
498 case AML_MULTI_NAME_PREFIX_OP:
500 /* More than one name_seg, search rules do not apply */
502 search_parent_flag = ACPI_NS_NO_UPSEARCH;
504 /* Extract segment count, point to first name segment */
507 num_segments = (u32) (u8) * path;
510 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
511 "Multi Pathname (%d Segments, Flags=%X)\n",
512 num_segments, flags));
517 * Not a Null name, no Dual or Multi prefix, hence there is
518 * only one name segment and Pathname is already pointing to it.
522 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
523 "Simple Pathname (1 segment, Flags=%X)\n",
528 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
532 * Search namespace for each segment of the name. Loop through and
533 * verify (or add to the namespace) each name segment.
535 * The object type is significant only at the last name
536 * segment. (We don't care about the types along the path, only
537 * the type of the final target object.)
539 this_search_type = ACPI_TYPE_ANY;
540 current_node = this_node;
541 while (num_segments && current_node) {
545 * This is the last segment, enable typechecking
547 this_search_type = type;
550 * Only allow automatic parent search (search rules) if the caller
551 * requested it AND we have a single, non-fully-qualified name_seg
553 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
554 (flags & ACPI_NS_SEARCH_PARENT)) {
555 local_flags |= ACPI_NS_SEARCH_PARENT;
558 /* Set error flag according to caller */
560 if (flags & ACPI_NS_ERROR_IF_FOUND) {
561 local_flags |= ACPI_NS_ERROR_IF_FOUND;
565 /* Extract one ACPI name from the front of the pathname */
567 ACPI_MOVE_32_TO_32(&simple_name, path);
569 /* Try to find the single (4 character) ACPI name */
572 acpi_ns_search_and_enter(simple_name, walk_state,
573 current_node, interpreter_mode,
574 this_search_type, local_flags,
576 if (ACPI_FAILURE(status)) {
577 if (status == AE_NOT_FOUND) {
579 /* Name not found in ACPI namespace */
581 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
582 "Name [%4.4s] not found in scope [%4.4s] %p\n",
583 (char *)&simple_name,
584 (char *)¤t_node->name,
588 *return_node = this_node;
589 return_ACPI_STATUS(status);
593 * Sanity typecheck of the target object:
595 * If 1) This is the last segment (num_segments == 0)
596 * 2) And we are looking for a specific type
597 * (Not checking for TYPE_ANY)
598 * 3) Which is not an alias
599 * 4) Which is not a local type (TYPE_SCOPE)
600 * 5) And the type of target object is known (not TYPE_ANY)
601 * 6) And target object does not match what we are looking for
603 * Then we have a type mismatch. Just warn and ignore it.
605 if ((num_segments == 0) &&
606 (type_to_check_for != ACPI_TYPE_ANY) &&
607 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
608 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) &&
609 (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) &&
610 (this_node->type != ACPI_TYPE_ANY) &&
611 (this_node->type != type_to_check_for)) {
613 /* Complain about a type mismatch */
615 ACPI_WARNING((AE_INFO,
616 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
617 ACPI_CAST_PTR(char, &simple_name),
618 acpi_ut_get_type_name(this_node->type),
619 acpi_ut_get_type_name
620 (type_to_check_for)));
624 * If this is the last name segment and we are not looking for a
625 * specific type, but the type of found object is known, use that type
626 * to see if it opens a scope.
628 if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
629 type = this_node->type;
632 /* Point to next name segment and make this node current */
634 path += ACPI_NAME_SIZE;
635 current_node = this_node;
639 * Always check if we need to open a new scope
641 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
643 * If entry is a type which opens a scope, push the new scope on the
646 if (acpi_ns_opens_scope(type)) {
648 acpi_ds_scope_stack_push(this_node, type,
650 if (ACPI_FAILURE(status)) {
651 return_ACPI_STATUS(status);
656 *return_node = this_node;
657 return_ACPI_STATUS(AE_OK);