1 /*******************************************************************************
2 *
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2013, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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.
25 *
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.
29 *
30 * NO WARRANTY
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.
42 */
43
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "amlcode.h"
47 #include "acnamesp.h"
48 #include "acdispat.h"
49
50 #define _COMPONENT ACPI_NAMESPACE
51 ACPI_MODULE_NAME("nsaccess")
52
53 /*******************************************************************************
54 *
55 * FUNCTION: acpi_ns_root_initialize
56 *
57 * PARAMETERS: None
58 *
59 * RETURN: Status
60 *
61 * DESCRIPTION: Allocate and initialize the default root named objects
62 *
63 * MUTEX: Locks namespace for entire execution
64 *
65 ******************************************************************************/
acpi_ns_root_initialize(void)66 acpi_status acpi_ns_root_initialize(void)
67 {
68 acpi_status status;
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;
73
74 ACPI_FUNCTION_TRACE(ns_root_initialize);
75
76 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
77 if (ACPI_FAILURE(status)) {
78 return_ACPI_STATUS(status);
79 }
80
81 /*
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.
84 */
85 if (acpi_gbl_root_node) {
86 status = AE_OK;
87 goto unlock_and_exit;
88 }
89
90 /*
91 * Tell the rest of the subsystem that the root is initialized
92 * (This is OK because the namespace is locked)
93 */
94 acpi_gbl_root_node = &acpi_gbl_root_node_struct;
95
96 /* Enter the pre-defined names in the name table */
97
98 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
99 "Entering predefined entries into namespace\n"));
100
101 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
102
103 /* _OSI is optional for now, will be permanent later */
104
105 if (!ACPI_STRCMP(init_val->name, "_OSI")
106 && !acpi_gbl_create_osi_method) {
107 continue;
108 }
109
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",
116 init_val->name));
117 continue;
118 }
119
120 /*
121 * Name entered successfully. If entry in pre_defined_names[] specifies
122 * an initial value, create the initial value.
123 */
124 if (init_val->val) {
125 status = acpi_os_predefined_override(init_val, &val);
126 if (ACPI_FAILURE(status)) {
127 ACPI_ERROR((AE_INFO,
128 "Could not override predefined %s",
129 init_val->name));
130 }
131
132 if (!val) {
133 val = init_val->val;
134 }
135
136 /*
137 * Entry requests an initial value, allocate a
138 * descriptor for it.
139 */
140 obj_desc =
141 acpi_ut_create_internal_object(init_val->type);
142 if (!obj_desc) {
143 status = AE_NO_MEMORY;
144 goto unlock_and_exit;
145 }
146
147 /*
148 * Convert value string from table entry to
149 * internal representation. Only types actually
150 * used for initial values are implemented here.
151 */
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;
157
158 #if defined (ACPI_ASL_COMPILER)
159
160 /* Save the parameter count for the iASL compiler */
161
162 new_node->value = obj_desc->method.param_count;
163 #else
164 /* Mark this as a very SPECIAL method */
165
166 obj_desc->method.info_flags =
167 ACPI_METHOD_INTERNAL_ONLY;
168 obj_desc->method.dispatch.implementation =
169 acpi_ut_osi_implementation;
170 #endif
171 break;
172
173 case ACPI_TYPE_INTEGER:
174
175 obj_desc->integer.value = ACPI_TO_INTEGER(val);
176 break;
177
178 case ACPI_TYPE_STRING:
179
180 /* Build an object around the static string */
181
182 obj_desc->string.length = (u32)ACPI_STRLEN(val);
183 obj_desc->string.pointer = val;
184 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
185 break;
186
187 case ACPI_TYPE_MUTEX:
188
189 obj_desc->mutex.node = new_node;
190 obj_desc->mutex.sync_level =
191 (u8) (ACPI_TO_INTEGER(val) - 1);
192
193 /* Create a mutex */
194
195 status =
196 acpi_os_create_mutex(&obj_desc->mutex.
197 os_mutex);
198 if (ACPI_FAILURE(status)) {
199 acpi_ut_remove_reference(obj_desc);
200 goto unlock_and_exit;
201 }
202
203 /* Special case for ACPI Global Lock */
204
205 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
206 acpi_gbl_global_lock_mutex = obj_desc;
207
208 /* Create additional counting semaphore for global lock */
209
210 status =
211 acpi_os_create_semaphore(1, 0,
212 &acpi_gbl_global_lock_semaphore);
213 if (ACPI_FAILURE(status)) {
214 acpi_ut_remove_reference
215 (obj_desc);
216 goto unlock_and_exit;
217 }
218 }
219 break;
220
221 default:
222
223 ACPI_ERROR((AE_INFO,
224 "Unsupported initial type value 0x%X",
225 init_val->type));
226 acpi_ut_remove_reference(obj_desc);
227 obj_desc = NULL;
228 continue;
229 }
230
231 /* Store pointer to value descriptor in the Node */
232
233 status = acpi_ns_attach_object(new_node, obj_desc,
234 obj_desc->common.type);
235
236 /* Remove local reference to the object */
237
238 acpi_ut_remove_reference(obj_desc);
239 }
240 }
241
242 unlock_and_exit:
243 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
244
245 /* Save a handle to "_GPE", it is always present */
246
247 if (ACPI_SUCCESS(status)) {
248 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
249 &acpi_gbl_fadt_gpe_device);
250 }
251
252 return_ACPI_STATUS(status);
253 }
254
255 /*******************************************************************************
256 *
257 * FUNCTION: acpi_ns_lookup
258 *
259 * PARAMETERS: scope_info - Current scope info block
260 * pathname - Search pathname, in internal format
261 * (as represented in the AML stream)
262 * type - Type associated with name
263 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
264 * flags - Flags describing the search restrictions
265 * walk_state - Current state of the walk
266 * return_node - Where the Node is placed (if found
267 * or created successfully)
268 *
269 * RETURN: Status
270 *
271 * DESCRIPTION: Find or enter the passed name in the name space.
272 * Log an error if name not found in Exec mode.
273 *
274 * MUTEX: Assumes namespace is locked.
275 *
276 ******************************************************************************/
277
278 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)279 acpi_ns_lookup(union acpi_generic_state *scope_info,
280 char *pathname,
281 acpi_object_type type,
282 acpi_interpreter_mode interpreter_mode,
283 u32 flags,
284 struct acpi_walk_state *walk_state,
285 struct acpi_namespace_node **return_node)
286 {
287 acpi_status status;
288 char *path = pathname;
289 struct acpi_namespace_node *prefix_node;
290 struct acpi_namespace_node *current_node = NULL;
291 struct acpi_namespace_node *this_node = NULL;
292 u32 num_segments;
293 u32 num_carats;
294 acpi_name simple_name;
295 acpi_object_type type_to_check_for;
296 acpi_object_type this_search_type;
297 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
298 u32 local_flags;
299
300 ACPI_FUNCTION_TRACE(ns_lookup);
301
302 if (!return_node) {
303 return_ACPI_STATUS(AE_BAD_PARAMETER);
304 }
305
306 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
307 *return_node = ACPI_ENTRY_NOT_FOUND;
308 acpi_gbl_ns_lookup_count++;
309
310 if (!acpi_gbl_root_node) {
311 return_ACPI_STATUS(AE_NO_NAMESPACE);
312 }
313
314 /* Get the prefix scope. A null scope means use the root scope */
315
316 if ((!scope_info) || (!scope_info->scope.node)) {
317 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
318 "Null scope prefix, using root node (%p)\n",
319 acpi_gbl_root_node));
320
321 prefix_node = acpi_gbl_root_node;
322 } else {
323 prefix_node = scope_info->scope.node;
324 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
325 ACPI_DESC_TYPE_NAMED) {
326 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
327 prefix_node,
328 acpi_ut_get_descriptor_name(prefix_node)));
329 return_ACPI_STATUS(AE_AML_INTERNAL);
330 }
331
332 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
333 /*
334 * This node might not be a actual "scope" node (such as a
335 * Device/Method, etc.) It could be a Package or other object
336 * node. Backup up the tree to find the containing scope node.
337 */
338 while (!acpi_ns_opens_scope(prefix_node->type) &&
339 prefix_node->type != ACPI_TYPE_ANY) {
340 prefix_node = prefix_node->parent;
341 }
342 }
343 }
344
345 /* Save type. TBD: may be no longer necessary */
346
347 type_to_check_for = type;
348
349 /*
350 * Begin examination of the actual pathname
351 */
352 if (!pathname) {
353
354 /* A Null name_path is allowed and refers to the root */
355
356 num_segments = 0;
357 this_node = acpi_gbl_root_node;
358 path = "";
359
360 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
361 "Null Pathname (Zero segments), Flags=%X\n",
362 flags));
363 } else {
364 /*
365 * Name pointer is valid (and must be in internal name format)
366 *
367 * Check for scope prefixes:
368 *
369 * As represented in the AML stream, a namepath consists of an
370 * optional scope prefix followed by a name segment part.
371 *
372 * If present, the scope prefix is either a Root Prefix (in
373 * which case the name is fully qualified), or one or more
374 * Parent Prefixes (in which case the name's scope is relative
375 * to the current scope).
376 */
377 if (*path == (u8) AML_ROOT_PREFIX) {
378
379 /* Pathname is fully qualified, start from the root */
380
381 this_node = acpi_gbl_root_node;
382 search_parent_flag = ACPI_NS_NO_UPSEARCH;
383
384 /* Point to name segment part */
385
386 path++;
387
388 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
389 "Path is absolute from root [%p]\n",
390 this_node));
391 } else {
392 /* Pathname is relative to current scope, start there */
393
394 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
395 "Searching relative to prefix scope [%4.4s] (%p)\n",
396 acpi_ut_get_node_name(prefix_node),
397 prefix_node));
398
399 /*
400 * Handle multiple Parent Prefixes (carat) by just getting
401 * the parent node for each prefix instance.
402 */
403 this_node = prefix_node;
404 num_carats = 0;
405 while (*path == (u8) AML_PARENT_PREFIX) {
406
407 /* Name is fully qualified, no search rules apply */
408
409 search_parent_flag = ACPI_NS_NO_UPSEARCH;
410
411 /*
412 * Point past this prefix to the name segment
413 * part or the next Parent Prefix
414 */
415 path++;
416
417 /* Backup to the parent node */
418
419 num_carats++;
420 this_node = this_node->parent;
421 if (!this_node) {
422
423 /* Current scope has no parent scope */
424
425 ACPI_ERROR((AE_INFO,
426 "ACPI path has too many parent prefixes (^) "
427 "- reached beyond root node"));
428 return_ACPI_STATUS(AE_NOT_FOUND);
429 }
430 }
431
432 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
433 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
434 "Search scope is [%4.4s], path has %u carat(s)\n",
435 acpi_ut_get_node_name
436 (this_node), num_carats));
437 }
438 }
439
440 /*
441 * Determine the number of ACPI name segments in this pathname.
442 *
443 * The segment part consists of either:
444 * - A Null name segment (0)
445 * - A dual_name_prefix followed by two 4-byte name segments
446 * - A multi_name_prefix followed by a byte indicating the
447 * number of segments and the segments themselves.
448 * - A single 4-byte name segment
449 *
450 * Examine the name prefix opcode, if any, to determine the number of
451 * segments.
452 */
453 switch (*path) {
454 case 0:
455 /*
456 * Null name after a root or parent prefixes. We already
457 * have the correct target node and there are no name segments.
458 */
459 num_segments = 0;
460 type = this_node->type;
461
462 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
463 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
464 flags));
465 break;
466
467 case AML_DUAL_NAME_PREFIX:
468
469 /* More than one name_seg, search rules do not apply */
470
471 search_parent_flag = ACPI_NS_NO_UPSEARCH;
472
473 /* Two segments, point to first name segment */
474
475 num_segments = 2;
476 path++;
477
478 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
479 "Dual Pathname (2 segments, Flags=%X)\n",
480 flags));
481 break;
482
483 case AML_MULTI_NAME_PREFIX_OP:
484
485 /* More than one name_seg, search rules do not apply */
486
487 search_parent_flag = ACPI_NS_NO_UPSEARCH;
488
489 /* Extract segment count, point to first name segment */
490
491 path++;
492 num_segments = (u32) (u8) * path;
493 path++;
494
495 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
496 "Multi Pathname (%u Segments, Flags=%X)\n",
497 num_segments, flags));
498 break;
499
500 default:
501 /*
502 * Not a Null name, no Dual or Multi prefix, hence there is
503 * only one name segment and Pathname is already pointing to it.
504 */
505 num_segments = 1;
506
507 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
508 "Simple Pathname (1 segment, Flags=%X)\n",
509 flags));
510 break;
511 }
512
513 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
514 }
515
516 /*
517 * Search namespace for each segment of the name. Loop through and
518 * verify (or add to the namespace) each name segment.
519 *
520 * The object type is significant only at the last name
521 * segment. (We don't care about the types along the path, only
522 * the type of the final target object.)
523 */
524 this_search_type = ACPI_TYPE_ANY;
525 current_node = this_node;
526 while (num_segments && current_node) {
527 num_segments--;
528 if (!num_segments) {
529
530 /* This is the last segment, enable typechecking */
531
532 this_search_type = type;
533
534 /*
535 * Only allow automatic parent search (search rules) if the caller
536 * requested it AND we have a single, non-fully-qualified name_seg
537 */
538 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
539 (flags & ACPI_NS_SEARCH_PARENT)) {
540 local_flags |= ACPI_NS_SEARCH_PARENT;
541 }
542
543 /* Set error flag according to caller */
544
545 if (flags & ACPI_NS_ERROR_IF_FOUND) {
546 local_flags |= ACPI_NS_ERROR_IF_FOUND;
547 }
548 }
549
550 /* Extract one ACPI name from the front of the pathname */
551
552 ACPI_MOVE_32_TO_32(&simple_name, path);
553
554 /* Try to find the single (4 character) ACPI name */
555
556 status =
557 acpi_ns_search_and_enter(simple_name, walk_state,
558 current_node, interpreter_mode,
559 this_search_type, local_flags,
560 &this_node);
561 if (ACPI_FAILURE(status)) {
562 if (status == AE_NOT_FOUND) {
563
564 /* Name not found in ACPI namespace */
565
566 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
567 "Name [%4.4s] not found in scope [%4.4s] %p\n",
568 (char *)&simple_name,
569 (char *)¤t_node->name,
570 current_node));
571 }
572
573 *return_node = this_node;
574 return_ACPI_STATUS(status);
575 }
576
577 /* More segments to follow? */
578
579 if (num_segments > 0) {
580 /*
581 * If we have an alias to an object that opens a scope (such as a
582 * device or processor), we need to dereference the alias here so
583 * that we can access any children of the original node (via the
584 * remaining segments).
585 */
586 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
587 if (!this_node->object) {
588 return_ACPI_STATUS(AE_NOT_EXIST);
589 }
590
591 if (acpi_ns_opens_scope
592 (((struct acpi_namespace_node *)
593 this_node->object)->type)) {
594 this_node =
595 (struct acpi_namespace_node *)
596 this_node->object;
597 }
598 }
599 }
600
601 /* Special handling for the last segment (num_segments == 0) */
602
603 else {
604 /*
605 * Sanity typecheck of the target object:
606 *
607 * If 1) This is the last segment (num_segments == 0)
608 * 2) And we are looking for a specific type
609 * (Not checking for TYPE_ANY)
610 * 3) Which is not an alias
611 * 4) Which is not a local type (TYPE_SCOPE)
612 * 5) And the type of target object is known (not TYPE_ANY)
613 * 6) And target object does not match what we are looking for
614 *
615 * Then we have a type mismatch. Just warn and ignore it.
616 */
617 if ((type_to_check_for != ACPI_TYPE_ANY) &&
618 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
619 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
620 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
621 && (this_node->type != ACPI_TYPE_ANY)
622 && (this_node->type != type_to_check_for)) {
623
624 /* Complain about a type mismatch */
625
626 ACPI_WARNING((AE_INFO,
627 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
628 ACPI_CAST_PTR(char, &simple_name),
629 acpi_ut_get_type_name(this_node->
630 type),
631 acpi_ut_get_type_name
632 (type_to_check_for)));
633 }
634
635 /*
636 * If this is the last name segment and we are not looking for a
637 * specific type, but the type of found object is known, use that
638 * type to (later) see if it opens a scope.
639 */
640 if (type == ACPI_TYPE_ANY) {
641 type = this_node->type;
642 }
643 }
644
645 /* Point to next name segment and make this node current */
646
647 path += ACPI_NAME_SIZE;
648 current_node = this_node;
649 }
650
651 /* Always check if we need to open a new scope */
652
653 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
654 /*
655 * If entry is a type which opens a scope, push the new scope on the
656 * scope stack.
657 */
658 if (acpi_ns_opens_scope(type)) {
659 status =
660 acpi_ds_scope_stack_push(this_node, type,
661 walk_state);
662 if (ACPI_FAILURE(status)) {
663 return_ACPI_STATUS(status);
664 }
665 }
666 }
667
668 *return_node = this_node;
669 return_ACPI_STATUS(AE_OK);
670 }
671