1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3 *
4 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
5 *
6 ******************************************************************************/
7
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "amlcode.h"
11 #include "acnamesp.h"
12 #include "acdispat.h"
13
14 #ifdef ACPI_ASL_COMPILER
15 #include "acdisasm.h"
16 #endif
17
18 #define _COMPONENT ACPI_NAMESPACE
19 ACPI_MODULE_NAME("nsaccess")
20
21 /*******************************************************************************
22 *
23 * FUNCTION: acpi_ns_root_initialize
24 *
25 * PARAMETERS: None
26 *
27 * RETURN: Status
28 *
29 * DESCRIPTION: Allocate and initialize the default root named objects
30 *
31 * MUTEX: Locks namespace for entire execution
32 *
33 ******************************************************************************/
34 acpi_status acpi_ns_root_initialize(void)
35 {
36 acpi_status status;
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;
42
43 ACPI_FUNCTION_TRACE(ns_root_initialize);
44
45 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
46 if (ACPI_FAILURE(status)) {
47 return_ACPI_STATUS(status);
48 }
49
50 /*
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.
53 */
54 if (acpi_gbl_root_node) {
55 status = AE_OK;
56 goto unlock_and_exit;
57 }
58
59 /*
60 * Tell the rest of the subsystem that the root is initialized
61 * (This is OK because the namespace is locked)
62 */
63 acpi_gbl_root_node = &acpi_gbl_root_node_struct;
64
65 /* Enter the predefined names in the name table */
66
67 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
68 "Entering predefined entries into namespace\n"));
69
70 /*
71 * Create the initial (default) namespace.
72 * This namespace looks like something similar to this:
73 *
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
84 */
85 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
86 status = AE_OK;
87
88 /* _OSI is optional for now, will be permanent later */
89
90 if (!strcmp(init_val->name, "_OSI")
91 && !acpi_gbl_create_osi_method) {
92 continue;
93 }
94
95 /*
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.
100 */
101 new_node =
102 ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_namespace_node));
103 if (!new_node) {
104 status = AE_NO_MEMORY;
105 goto unlock_and_exit;
106 }
107
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;
111
112 if (!prev_node) {
113 acpi_gbl_root_node_struct.child = new_node;
114 } else {
115 prev_node->peer = new_node;
116 }
117
118 new_node->parent = &acpi_gbl_root_node_struct;
119 prev_node = new_node;
120
121 /*
122 * Name entered successfully. If entry in pre_defined_names[] specifies
123 * an initial value, create the initial value.
124 */
125 if (init_val->val) {
126 status = acpi_os_predefined_override(init_val, &val);
127 if (ACPI_FAILURE(status)) {
128 ACPI_ERROR((AE_INFO,
129 "Could not override predefined %s",
130 init_val->name));
131 }
132
133 if (!val) {
134 val = init_val->val;
135 }
136
137 /*
138 * Entry requests an initial value, allocate a
139 * descriptor for it.
140 */
141 obj_desc =
142 acpi_ut_create_internal_object(init_val->type);
143 if (!obj_desc) {
144 status = AE_NO_MEMORY;
145 goto unlock_and_exit;
146 }
147
148 /*
149 * Convert value string from table entry to
150 * internal representation. Only types actually
151 * used for initial values are implemented here.
152 */
153 switch (init_val->type) {
154 case ACPI_TYPE_METHOD:
155
156 obj_desc->method.param_count =
157 (u8) ACPI_TO_INTEGER(val);
158 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
159
160 #if defined (ACPI_ASL_COMPILER)
161
162 /* Save the parameter count for the iASL compiler */
163
164 new_node->value = obj_desc->method.param_count;
165 #else
166 /* Mark this as a very SPECIAL method (_OSI) */
167
168 obj_desc->method.info_flags =
169 ACPI_METHOD_INTERNAL_ONLY;
170 obj_desc->method.dispatch.implementation =
171 acpi_ut_osi_implementation;
172 #endif
173 break;
174
175 case ACPI_TYPE_INTEGER:
176
177 obj_desc->integer.value = ACPI_TO_INTEGER(val);
178 break;
179
180 case ACPI_TYPE_STRING:
181
182 /* Build an object around the static string */
183
184 obj_desc->string.length = (u32)strlen(val);
185 obj_desc->string.pointer = val;
186 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
187 break;
188
189 case ACPI_TYPE_MUTEX:
190
191 obj_desc->mutex.node = new_node;
192 obj_desc->mutex.sync_level =
193 (u8) (ACPI_TO_INTEGER(val) - 1);
194
195 /* Create a mutex */
196
197 status =
198 acpi_os_create_mutex(&obj_desc->mutex.
199 os_mutex);
200 if (ACPI_FAILURE(status)) {
201 acpi_ut_remove_reference(obj_desc);
202 goto unlock_and_exit;
203 }
204
205 /* Special case for ACPI Global Lock */
206
207 if (strcmp(init_val->name, "_GL_") == 0) {
208 acpi_gbl_global_lock_mutex = obj_desc;
209
210 /* Create additional counting semaphore for global lock */
211
212 status =
213 acpi_os_create_semaphore(1, 0,
214 &acpi_gbl_global_lock_semaphore);
215 if (ACPI_FAILURE(status)) {
216 acpi_ut_remove_reference
217 (obj_desc);
218 goto unlock_and_exit;
219 }
220 }
221 break;
222
223 default:
224
225 ACPI_ERROR((AE_INFO,
226 "Unsupported initial type value 0x%X",
227 init_val->type));
228 acpi_ut_remove_reference(obj_desc);
229 obj_desc = NULL;
230 continue;
231 }
232
233 /* Store pointer to value descriptor in the Node */
234
235 status = acpi_ns_attach_object(new_node, obj_desc,
236 obj_desc->common.type);
237
238 /* Remove local reference to the object */
239
240 acpi_ut_remove_reference(obj_desc);
241 }
242 }
243
244 unlock_and_exit:
245 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
246
247 /* Save a handle to "_GPE", it is always present */
248
249 if (ACPI_SUCCESS(status)) {
250 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
251 &acpi_gbl_fadt_gpe_device);
252 }
253
254 return_ACPI_STATUS(status);
255 }
256
257 /*******************************************************************************
258 *
259 * FUNCTION: acpi_ns_lookup
260 *
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)
270 *
271 * RETURN: Status
272 *
273 * DESCRIPTION: Find or enter the passed name in the name space.
274 * Log an error if name not found in Exec mode.
275 *
276 * MUTEX: Assumes namespace is locked.
277 *
278 ******************************************************************************/
279
280 acpi_status
281 acpi_ns_lookup(union acpi_generic_state *scope_info,
282 char *pathname,
283 acpi_object_type type,
284 acpi_interpreter_mode interpreter_mode,
285 u32 flags,
286 struct acpi_walk_state *walk_state,
287 struct acpi_namespace_node **return_node)
288 {
289 acpi_status status;
290 char *path = pathname;
291 char *external_path;
292 struct acpi_namespace_node *prefix_node;
293 struct acpi_namespace_node *current_node = NULL;
294 struct acpi_namespace_node *this_node = NULL;
295 u32 num_segments;
296 u32 num_carats;
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;
301 u32 local_flags;
302 acpi_interpreter_mode local_interpreter_mode;
303
304 ACPI_FUNCTION_TRACE(ns_lookup);
305
306 if (!return_node) {
307 return_ACPI_STATUS(AE_BAD_PARAMETER);
308 }
309
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++;
315
316 if (!acpi_gbl_root_node) {
317 return_ACPI_STATUS(AE_NO_NAMESPACE);
318 }
319
320 /* Get the prefix scope. A null scope means use the root scope */
321
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));
326
327 prefix_node = acpi_gbl_root_node;
328 } else {
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]",
333 prefix_node,
334 acpi_ut_get_descriptor_name(prefix_node)));
335 return_ACPI_STATUS(AE_AML_INTERNAL);
336 }
337
338 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
339 /*
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.
343 */
344 while (!acpi_ns_opens_scope(prefix_node->type) &&
345 prefix_node->type != ACPI_TYPE_ANY) {
346 prefix_node = prefix_node->parent;
347 }
348 }
349 }
350
351 /* Save type. TBD: may be no longer necessary */
352
353 type_to_check_for = type;
354
355 /*
356 * Begin examination of the actual pathname
357 */
358 if (!pathname) {
359
360 /* A Null name_path is allowed and refers to the root */
361
362 num_segments = 0;
363 this_node = acpi_gbl_root_node;
364 path = "";
365
366 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
367 "Null Pathname (Zero segments), Flags=%X\n",
368 flags));
369 } else {
370 /*
371 * Name pointer is valid (and must be in internal name format)
372 *
373 * Check for scope prefixes:
374 *
375 * As represented in the AML stream, a namepath consists of an
376 * optional scope prefix followed by a name segment part.
377 *
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).
382 */
383 if (*path == (u8) AML_ROOT_PREFIX) {
384
385 /* Pathname is fully qualified, start from the root */
386
387 this_node = acpi_gbl_root_node;
388 search_parent_flag = ACPI_NS_NO_UPSEARCH;
389
390 /* Point to name segment part */
391
392 path++;
393
394 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
395 "Path is absolute from root [%p]\n",
396 this_node));
397 } else {
398 /* Pathname is relative to current scope, start there */
399
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),
403 prefix_node));
404
405 /*
406 * Handle multiple Parent Prefixes (carat) by just getting
407 * the parent node for each prefix instance.
408 */
409 this_node = prefix_node;
410 num_carats = 0;
411 while (*path == (u8) AML_PARENT_PREFIX) {
412
413 /* Name is fully qualified, no search rules apply */
414
415 search_parent_flag = ACPI_NS_NO_UPSEARCH;
416
417 /*
418 * Point past this prefix to the name segment
419 * part or the next Parent Prefix
420 */
421 path++;
422
423 /* Backup to the parent node */
424
425 num_carats++;
426 this_node = this_node->parent;
427 if (!this_node) {
428 /*
429 * Current scope has no parent scope. Externalize
430 * the internal path for error message.
431 */
432 status =
433 acpi_ns_externalize_name
434 (ACPI_UINT32_MAX, pathname, NULL,
435 &external_path);
436 if (ACPI_SUCCESS(status)) {
437 ACPI_ERROR((AE_INFO,
438 "%s: Path has too many parent prefixes (^)",
439 external_path));
440
441 ACPI_FREE(external_path);
442 }
443
444 return_ACPI_STATUS(AE_NOT_FOUND);
445 }
446 }
447
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));
453 }
454 }
455
456 /*
457 * Determine the number of ACPI name segments in this pathname.
458 *
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
465 *
466 * Examine the name prefix opcode, if any, to determine the number of
467 * segments.
468 */
469 switch (*path) {
470 case 0:
471 /*
472 * Null name after a root or parent prefixes. We already
473 * have the correct target node and there are no name segments.
474 */
475 num_segments = 0;
476 type = this_node->type;
477
478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
479 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
480 flags));
481 break;
482
483 case AML_DUAL_NAME_PREFIX:
484
485 /* More than one name_seg, search rules do not apply */
486
487 search_parent_flag = ACPI_NS_NO_UPSEARCH;
488
489 /* Two segments, point to first name segment */
490
491 num_segments = 2;
492 path++;
493
494 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
495 "Dual Pathname (2 segments, Flags=%X)\n",
496 flags));
497 break;
498
499 case AML_MULTI_NAME_PREFIX:
500
501 /* More than one name_seg, search rules do not apply */
502
503 search_parent_flag = ACPI_NS_NO_UPSEARCH;
504
505 /* Extract segment count, point to first name segment */
506
507 path++;
508 num_segments = (u32) (u8) * path;
509 path++;
510
511 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
512 "Multi Pathname (%u Segments, Flags=%X)\n",
513 num_segments, flags));
514 break;
515
516 default:
517 /*
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.
520 */
521 num_segments = 1;
522
523 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
524 "Simple Pathname (1 segment, Flags=%X)\n",
525 flags));
526 break;
527 }
528
529 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
530 }
531
532 /*
533 * Search namespace for each segment of the name. Loop through and
534 * verify (or add to the namespace) each name segment.
535 *
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.)
539 */
540 this_search_type = ACPI_TYPE_ANY;
541 current_node = this_node;
542
543 while (num_segments && current_node) {
544 num_segments--;
545 if (!num_segments) {
546
547 /* This is the last segment, enable typechecking */
548
549 this_search_type = type;
550
551 /*
552 * Only allow automatic parent search (search rules) if the caller
553 * requested it AND we have a single, non-fully-qualified name_seg
554 */
555 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
556 (flags & ACPI_NS_SEARCH_PARENT)) {
557 local_flags |= ACPI_NS_SEARCH_PARENT;
558 }
559
560 /* Set error flag according to caller */
561
562 if (flags & ACPI_NS_ERROR_IF_FOUND) {
563 local_flags |= ACPI_NS_ERROR_IF_FOUND;
564 }
565
566 /* Set override flag according to caller */
567
568 if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
569 local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;
570 }
571 }
572
573 /* Handle opcodes that create a new name_seg via a full name_path */
574
575 local_interpreter_mode = interpreter_mode;
576 if ((flags & ACPI_NS_PREFIX_MUST_EXIST) && (num_segments > 0)) {
577
578 /* Every element of the path must exist (except for the final name_seg) */
579
580 local_interpreter_mode = ACPI_IMODE_EXECUTE;
581 }
582
583 /* Extract one ACPI name from the front of the pathname */
584
585 ACPI_MOVE_32_TO_32(&simple_name, path);
586
587 /* Try to find the single (4 character) ACPI name */
588
589 status =
590 acpi_ns_search_and_enter(simple_name, walk_state,
591 current_node,
592 local_interpreter_mode,
593 this_search_type, local_flags,
594 &this_node);
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);
602 }
603 #endif
604 /* Name not found in ACPI namespace */
605
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,
610 current_node));
611 }
612 #ifdef ACPI_EXEC_APP
613 if ((status == AE_ALREADY_EXISTS) &&
614 (this_node->flags & ANOBJ_NODE_EARLY_INIT)) {
615 this_node->flags &= ~ANOBJ_NODE_EARLY_INIT;
616 status = AE_OK;
617 }
618 #endif
619
620 #ifdef ACPI_ASL_COMPILER
621 /*
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.
628 */
629 if (acpi_gbl_disasm_flag &&
630 (status == AE_ALREADY_EXISTS) &&
631 ((this_node->flags & ANOBJ_IS_EXTERNAL) ||
632 (walk_state
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
638 (this_node);
639 }
640 break;
641 }
642 #endif
643
644 *return_node = this_node;
645 return_ACPI_STATUS(status);
646 }
647
648 /* More segments to follow? */
649
650 if (num_segments > 0) {
651 /*
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).
656 */
657 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
658 if (!this_node->object) {
659 return_ACPI_STATUS(AE_NOT_EXIST);
660 }
661
662 if (acpi_ns_opens_scope
663 (((struct acpi_namespace_node *)
664 this_node->object)->type)) {
665 this_node =
666 (struct acpi_namespace_node *)
667 this_node->object;
668 }
669 }
670 }
671
672 /* Special handling for the last segment (num_segments == 0) */
673
674 else {
675 /*
676 * Sanity typecheck of the target object:
677 *
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
685 *
686 * Then we have a type mismatch. Just warn and ignore it.
687 */
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)) {
694
695 /* Complain about a type mismatch */
696
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->
701 type),
702 acpi_ut_get_type_name
703 (type_to_check_for)));
704 }
705
706 /*
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.
710 */
711 if (type == ACPI_TYPE_ANY) {
712 type = this_node->type;
713 }
714 }
715
716 /* Point to next name segment and make this node current */
717
718 path += ACPI_NAMESEG_SIZE;
719 current_node = this_node;
720 }
721
722 /* Always check if we need to open a new scope */
723
724 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
725 /*
726 * If entry is a type which opens a scope, push the new scope on the
727 * scope stack.
728 */
729 if (acpi_ns_opens_scope(type)) {
730 status =
731 acpi_ds_scope_stack_push(this_node, type,
732 walk_state);
733 if (ACPI_FAILURE(status)) {
734 return_ACPI_STATUS(status);
735 }
736 }
737 }
738 #ifdef ACPI_EXEC_APP
739 if (flags & ACPI_NS_EARLY_INIT) {
740 this_node->flags |= ANOBJ_NODE_EARLY_INIT;
741 }
742 #endif
743
744 *return_node = this_node;
745 return_ACPI_STATUS(AE_OK);
746 }