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 ******************************************************************************/
acpi_ns_root_initialize(void)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 union acpi_operand_object *obj_desc;
40 acpi_string val = NULL;
41
42 ACPI_FUNCTION_TRACE(ns_root_initialize);
43
44 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
45 if (ACPI_FAILURE(status)) {
46 return_ACPI_STATUS(status);
47 }
48
49 /*
50 * The global root ptr is initially NULL, so a non-NULL value indicates
51 * that acpi_ns_root_initialize() has already been called; just return.
52 */
53 if (acpi_gbl_root_node) {
54 status = AE_OK;
55 goto unlock_and_exit;
56 }
57
58 /*
59 * Tell the rest of the subsystem that the root is initialized
60 * (This is OK because the namespace is locked)
61 */
62 acpi_gbl_root_node = &acpi_gbl_root_node_struct;
63
64 /* Enter the pre-defined names in the name table */
65
66 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
67 "Entering predefined entries into namespace\n"));
68
69 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
70
71 /* _OSI is optional for now, will be permanent later */
72
73 if (!strcmp(init_val->name, "_OSI")
74 && !acpi_gbl_create_osi_method) {
75 continue;
76 }
77
78 status =
79 acpi_ns_lookup(NULL, ACPI_CAST_PTR(char, init_val->name),
80 init_val->type, ACPI_IMODE_LOAD_PASS2,
81 ACPI_NS_NO_UPSEARCH, NULL, &new_node);
82 if (ACPI_FAILURE(status)) {
83 ACPI_EXCEPTION((AE_INFO, status,
84 "Could not create predefined name %s",
85 init_val->name));
86 continue;
87 }
88
89 /*
90 * Name entered successfully. If entry in pre_defined_names[] specifies
91 * an initial value, create the initial value.
92 */
93 if (init_val->val) {
94 status = acpi_os_predefined_override(init_val, &val);
95 if (ACPI_FAILURE(status)) {
96 ACPI_ERROR((AE_INFO,
97 "Could not override predefined %s",
98 init_val->name));
99 }
100
101 if (!val) {
102 val = init_val->val;
103 }
104
105 /*
106 * Entry requests an initial value, allocate a
107 * descriptor for it.
108 */
109 obj_desc =
110 acpi_ut_create_internal_object(init_val->type);
111 if (!obj_desc) {
112 status = AE_NO_MEMORY;
113 goto unlock_and_exit;
114 }
115
116 /*
117 * Convert value string from table entry to
118 * internal representation. Only types actually
119 * used for initial values are implemented here.
120 */
121 switch (init_val->type) {
122 case ACPI_TYPE_METHOD:
123
124 obj_desc->method.param_count =
125 (u8) ACPI_TO_INTEGER(val);
126 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
127
128 #if defined (ACPI_ASL_COMPILER)
129
130 /* Save the parameter count for the iASL compiler */
131
132 new_node->value = obj_desc->method.param_count;
133 #else
134 /* Mark this as a very SPECIAL method */
135
136 obj_desc->method.info_flags =
137 ACPI_METHOD_INTERNAL_ONLY;
138 obj_desc->method.dispatch.implementation =
139 acpi_ut_osi_implementation;
140 #endif
141 break;
142
143 case ACPI_TYPE_INTEGER:
144
145 obj_desc->integer.value = ACPI_TO_INTEGER(val);
146 break;
147
148 case ACPI_TYPE_STRING:
149
150 /* Build an object around the static string */
151
152 obj_desc->string.length = (u32)strlen(val);
153 obj_desc->string.pointer = val;
154 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
155 break;
156
157 case ACPI_TYPE_MUTEX:
158
159 obj_desc->mutex.node = new_node;
160 obj_desc->mutex.sync_level =
161 (u8) (ACPI_TO_INTEGER(val) - 1);
162
163 /* Create a mutex */
164
165 status =
166 acpi_os_create_mutex(&obj_desc->mutex.
167 os_mutex);
168 if (ACPI_FAILURE(status)) {
169 acpi_ut_remove_reference(obj_desc);
170 goto unlock_and_exit;
171 }
172
173 /* Special case for ACPI Global Lock */
174
175 if (strcmp(init_val->name, "_GL_") == 0) {
176 acpi_gbl_global_lock_mutex = obj_desc;
177
178 /* Create additional counting semaphore for global lock */
179
180 status =
181 acpi_os_create_semaphore(1, 0,
182 &acpi_gbl_global_lock_semaphore);
183 if (ACPI_FAILURE(status)) {
184 acpi_ut_remove_reference
185 (obj_desc);
186 goto unlock_and_exit;
187 }
188 }
189 break;
190
191 default:
192
193 ACPI_ERROR((AE_INFO,
194 "Unsupported initial type value 0x%X",
195 init_val->type));
196 acpi_ut_remove_reference(obj_desc);
197 obj_desc = NULL;
198 continue;
199 }
200
201 /* Store pointer to value descriptor in the Node */
202
203 status = acpi_ns_attach_object(new_node, obj_desc,
204 obj_desc->common.type);
205
206 /* Remove local reference to the object */
207
208 acpi_ut_remove_reference(obj_desc);
209 }
210 }
211
212 unlock_and_exit:
213 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
214
215 /* Save a handle to "_GPE", it is always present */
216
217 if (ACPI_SUCCESS(status)) {
218 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
219 &acpi_gbl_fadt_gpe_device);
220 }
221
222 return_ACPI_STATUS(status);
223 }
224
225 /*******************************************************************************
226 *
227 * FUNCTION: acpi_ns_lookup
228 *
229 * PARAMETERS: scope_info - Current scope info block
230 * pathname - Search pathname, in internal format
231 * (as represented in the AML stream)
232 * type - Type associated with name
233 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
234 * flags - Flags describing the search restrictions
235 * walk_state - Current state of the walk
236 * return_node - Where the Node is placed (if found
237 * or created successfully)
238 *
239 * RETURN: Status
240 *
241 * DESCRIPTION: Find or enter the passed name in the name space.
242 * Log an error if name not found in Exec mode.
243 *
244 * MUTEX: Assumes namespace is locked.
245 *
246 ******************************************************************************/
247
248 acpi_status
acpi_ns_lookup(union acpi_generic_state * scope_info,char * pathname,acpi_object_type type,acpi_interpreter_mode interpreter_mode,u32 flags,struct acpi_walk_state * walk_state,struct acpi_namespace_node ** return_node)249 acpi_ns_lookup(union acpi_generic_state *scope_info,
250 char *pathname,
251 acpi_object_type type,
252 acpi_interpreter_mode interpreter_mode,
253 u32 flags,
254 struct acpi_walk_state *walk_state,
255 struct acpi_namespace_node **return_node)
256 {
257 acpi_status status;
258 char *path = pathname;
259 char *external_path;
260 struct acpi_namespace_node *prefix_node;
261 struct acpi_namespace_node *current_node = NULL;
262 struct acpi_namespace_node *this_node = NULL;
263 u32 num_segments;
264 u32 num_carats;
265 acpi_name simple_name;
266 acpi_object_type type_to_check_for;
267 acpi_object_type this_search_type;
268 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
269 u32 local_flags;
270
271 ACPI_FUNCTION_TRACE(ns_lookup);
272
273 if (!return_node) {
274 return_ACPI_STATUS(AE_BAD_PARAMETER);
275 }
276
277 local_flags = flags &
278 ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
279 ACPI_NS_SEARCH_PARENT);
280 *return_node = ACPI_ENTRY_NOT_FOUND;
281 acpi_gbl_ns_lookup_count++;
282
283 if (!acpi_gbl_root_node) {
284 return_ACPI_STATUS(AE_NO_NAMESPACE);
285 }
286
287 /* Get the prefix scope. A null scope means use the root scope */
288
289 if ((!scope_info) || (!scope_info->scope.node)) {
290 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
291 "Null scope prefix, using root node (%p)\n",
292 acpi_gbl_root_node));
293
294 prefix_node = acpi_gbl_root_node;
295 } else {
296 prefix_node = scope_info->scope.node;
297 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
298 ACPI_DESC_TYPE_NAMED) {
299 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
300 prefix_node,
301 acpi_ut_get_descriptor_name(prefix_node)));
302 return_ACPI_STATUS(AE_AML_INTERNAL);
303 }
304
305 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
306 /*
307 * This node might not be a actual "scope" node (such as a
308 * Device/Method, etc.) It could be a Package or other object
309 * node. Backup up the tree to find the containing scope node.
310 */
311 while (!acpi_ns_opens_scope(prefix_node->type) &&
312 prefix_node->type != ACPI_TYPE_ANY) {
313 prefix_node = prefix_node->parent;
314 }
315 }
316 }
317
318 /* Save type. TBD: may be no longer necessary */
319
320 type_to_check_for = type;
321
322 /*
323 * Begin examination of the actual pathname
324 */
325 if (!pathname) {
326
327 /* A Null name_path is allowed and refers to the root */
328
329 num_segments = 0;
330 this_node = acpi_gbl_root_node;
331 path = "";
332
333 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
334 "Null Pathname (Zero segments), Flags=%X\n",
335 flags));
336 } else {
337 /*
338 * Name pointer is valid (and must be in internal name format)
339 *
340 * Check for scope prefixes:
341 *
342 * As represented in the AML stream, a namepath consists of an
343 * optional scope prefix followed by a name segment part.
344 *
345 * If present, the scope prefix is either a Root Prefix (in
346 * which case the name is fully qualified), or one or more
347 * Parent Prefixes (in which case the name's scope is relative
348 * to the current scope).
349 */
350 if (*path == (u8) AML_ROOT_PREFIX) {
351
352 /* Pathname is fully qualified, start from the root */
353
354 this_node = acpi_gbl_root_node;
355 search_parent_flag = ACPI_NS_NO_UPSEARCH;
356
357 /* Point to name segment part */
358
359 path++;
360
361 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
362 "Path is absolute from root [%p]\n",
363 this_node));
364 } else {
365 /* Pathname is relative to current scope, start there */
366
367 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
368 "Searching relative to prefix scope [%4.4s] (%p)\n",
369 acpi_ut_get_node_name(prefix_node),
370 prefix_node));
371
372 /*
373 * Handle multiple Parent Prefixes (carat) by just getting
374 * the parent node for each prefix instance.
375 */
376 this_node = prefix_node;
377 num_carats = 0;
378 while (*path == (u8) AML_PARENT_PREFIX) {
379
380 /* Name is fully qualified, no search rules apply */
381
382 search_parent_flag = ACPI_NS_NO_UPSEARCH;
383
384 /*
385 * Point past this prefix to the name segment
386 * part or the next Parent Prefix
387 */
388 path++;
389
390 /* Backup to the parent node */
391
392 num_carats++;
393 this_node = this_node->parent;
394 if (!this_node) {
395 /*
396 * Current scope has no parent scope. Externalize
397 * the internal path for error message.
398 */
399 status =
400 acpi_ns_externalize_name
401 (ACPI_UINT32_MAX, pathname, NULL,
402 &external_path);
403 if (ACPI_SUCCESS(status)) {
404 ACPI_ERROR((AE_INFO,
405 "%s: Path has too many parent prefixes (^)",
406 external_path));
407
408 ACPI_FREE(external_path);
409 }
410
411 return_ACPI_STATUS(AE_NOT_FOUND);
412 }
413 }
414
415 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
416 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
417 "Search scope is [%4.4s], path has %u carat(s)\n",
418 acpi_ut_get_node_name
419 (this_node), num_carats));
420 }
421 }
422
423 /*
424 * Determine the number of ACPI name segments in this pathname.
425 *
426 * The segment part consists of either:
427 * - A Null name segment (0)
428 * - A dual_name_prefix followed by two 4-byte name segments
429 * - A multi_name_prefix followed by a byte indicating the
430 * number of segments and the segments themselves.
431 * - A single 4-byte name segment
432 *
433 * Examine the name prefix opcode, if any, to determine the number of
434 * segments.
435 */
436 switch (*path) {
437 case 0:
438 /*
439 * Null name after a root or parent prefixes. We already
440 * have the correct target node and there are no name segments.
441 */
442 num_segments = 0;
443 type = this_node->type;
444
445 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
446 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
447 flags));
448 break;
449
450 case AML_DUAL_NAME_PREFIX:
451
452 /* More than one name_seg, search rules do not apply */
453
454 search_parent_flag = ACPI_NS_NO_UPSEARCH;
455
456 /* Two segments, point to first name segment */
457
458 num_segments = 2;
459 path++;
460
461 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
462 "Dual Pathname (2 segments, Flags=%X)\n",
463 flags));
464 break;
465
466 case AML_MULTI_NAME_PREFIX:
467
468 /* More than one name_seg, search rules do not apply */
469
470 search_parent_flag = ACPI_NS_NO_UPSEARCH;
471
472 /* Extract segment count, point to first name segment */
473
474 path++;
475 num_segments = (u32) (u8) * path;
476 path++;
477
478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
479 "Multi Pathname (%u Segments, Flags=%X)\n",
480 num_segments, flags));
481 break;
482
483 default:
484 /*
485 * Not a Null name, no Dual or Multi prefix, hence there is
486 * only one name segment and Pathname is already pointing to it.
487 */
488 num_segments = 1;
489
490 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
491 "Simple Pathname (1 segment, Flags=%X)\n",
492 flags));
493 break;
494 }
495
496 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
497 }
498
499 /*
500 * Search namespace for each segment of the name. Loop through and
501 * verify (or add to the namespace) each name segment.
502 *
503 * The object type is significant only at the last name
504 * segment. (We don't care about the types along the path, only
505 * the type of the final target object.)
506 */
507 this_search_type = ACPI_TYPE_ANY;
508 current_node = this_node;
509 while (num_segments && current_node) {
510 num_segments--;
511 if (!num_segments) {
512
513 /* This is the last segment, enable typechecking */
514
515 this_search_type = type;
516
517 /*
518 * Only allow automatic parent search (search rules) if the caller
519 * requested it AND we have a single, non-fully-qualified name_seg
520 */
521 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
522 (flags & ACPI_NS_SEARCH_PARENT)) {
523 local_flags |= ACPI_NS_SEARCH_PARENT;
524 }
525
526 /* Set error flag according to caller */
527
528 if (flags & ACPI_NS_ERROR_IF_FOUND) {
529 local_flags |= ACPI_NS_ERROR_IF_FOUND;
530 }
531
532 /* Set override flag according to caller */
533
534 if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
535 local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;
536 }
537 }
538
539 /* Extract one ACPI name from the front of the pathname */
540
541 ACPI_MOVE_32_TO_32(&simple_name, path);
542
543 /* Try to find the single (4 character) ACPI name */
544
545 status =
546 acpi_ns_search_and_enter(simple_name, walk_state,
547 current_node, interpreter_mode,
548 this_search_type, local_flags,
549 &this_node);
550 if (ACPI_FAILURE(status)) {
551 if (status == AE_NOT_FOUND) {
552
553 /* Name not found in ACPI namespace */
554
555 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
556 "Name [%4.4s] not found in scope [%4.4s] %p\n",
557 (char *)&simple_name,
558 (char *)¤t_node->name,
559 current_node));
560 }
561 #ifdef ACPI_EXEC_APP
562 if ((status == AE_ALREADY_EXISTS) &&
563 (this_node->flags & ANOBJ_NODE_EARLY_INIT)) {
564 this_node->flags &= ~ANOBJ_NODE_EARLY_INIT;
565 status = AE_OK;
566 }
567 #endif
568
569 #ifdef ACPI_ASL_COMPILER
570 /*
571 * If this ACPI name already exists within the namespace as an
572 * external declaration, then mark the external as a conflicting
573 * declaration and proceed to process the current node as if it did
574 * not exist in the namespace. If this node is not processed as
575 * normal, then it could cause improper namespace resolution
576 * by failing to open a new scope.
577 */
578 if (acpi_gbl_disasm_flag &&
579 (status == AE_ALREADY_EXISTS) &&
580 ((this_node->flags & ANOBJ_IS_EXTERNAL) ||
581 (walk_state
582 && walk_state->opcode == AML_EXTERNAL_OP))) {
583 this_node->flags &= ~ANOBJ_IS_EXTERNAL;
584 this_node->type = (u8)this_search_type;
585 if (walk_state->opcode != AML_EXTERNAL_OP) {
586 acpi_dm_mark_external_conflict
587 (this_node);
588 }
589 break;
590 }
591 #endif
592
593 *return_node = this_node;
594 return_ACPI_STATUS(status);
595 }
596
597 /* More segments to follow? */
598
599 if (num_segments > 0) {
600 /*
601 * If we have an alias to an object that opens a scope (such as a
602 * device or processor), we need to dereference the alias here so
603 * that we can access any children of the original node (via the
604 * remaining segments).
605 */
606 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
607 if (!this_node->object) {
608 return_ACPI_STATUS(AE_NOT_EXIST);
609 }
610
611 if (acpi_ns_opens_scope
612 (((struct acpi_namespace_node *)
613 this_node->object)->type)) {
614 this_node =
615 (struct acpi_namespace_node *)
616 this_node->object;
617 }
618 }
619 }
620
621 /* Special handling for the last segment (num_segments == 0) */
622
623 else {
624 /*
625 * Sanity typecheck of the target object:
626 *
627 * If 1) This is the last segment (num_segments == 0)
628 * 2) And we are looking for a specific type
629 * (Not checking for TYPE_ANY)
630 * 3) Which is not an alias
631 * 4) Which is not a local type (TYPE_SCOPE)
632 * 5) And the type of target object is known (not TYPE_ANY)
633 * 6) And target object does not match what we are looking for
634 *
635 * Then we have a type mismatch. Just warn and ignore it.
636 */
637 if ((type_to_check_for != ACPI_TYPE_ANY) &&
638 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
639 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
640 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
641 && (this_node->type != ACPI_TYPE_ANY)
642 && (this_node->type != type_to_check_for)) {
643
644 /* Complain about a type mismatch */
645
646 ACPI_WARNING((AE_INFO,
647 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
648 ACPI_CAST_PTR(char, &simple_name),
649 acpi_ut_get_type_name(this_node->
650 type),
651 acpi_ut_get_type_name
652 (type_to_check_for)));
653 }
654
655 /*
656 * If this is the last name segment and we are not looking for a
657 * specific type, but the type of found object is known, use that
658 * type to (later) see if it opens a scope.
659 */
660 if (type == ACPI_TYPE_ANY) {
661 type = this_node->type;
662 }
663 }
664
665 /* Point to next name segment and make this node current */
666
667 path += ACPI_NAME_SIZE;
668 current_node = this_node;
669 }
670
671 /* Always check if we need to open a new scope */
672
673 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
674 /*
675 * If entry is a type which opens a scope, push the new scope on the
676 * scope stack.
677 */
678 if (acpi_ns_opens_scope(type)) {
679 status =
680 acpi_ds_scope_stack_push(this_node, type,
681 walk_state);
682 if (ACPI_FAILURE(status)) {
683 return_ACPI_STATUS(status);
684 }
685 }
686 }
687 #ifdef ACPI_EXEC_APP
688 if (flags & ACPI_NS_EARLY_INIT) {
689 this_node->flags |= ANOBJ_NODE_EARLY_INIT;
690 }
691 #endif
692
693 *return_node = this_node;
694 return_ACPI_STATUS(AE_OK);
695 }
696
