?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
ACPICA: Fix to allow aliases within ASL namepaths
[linux-2.6/mini2440.git] / drivers / acpi / namespace / nsaccess.c
blob35b0e46bd095fe0947d40bb2383e3c7f387bd7f3
1 /*******************************************************************************
2 *
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2008, 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 <acpi/amlcode.h>
46 #include <acpi/acnamesp.h>
47 #include <acpi/acdispat.h>
48
49 #define _COMPONENT ACPI_NAMESPACE
50 ACPI_MODULE_NAME("nsaccess")
51
52 /*******************************************************************************
53 *
54 * FUNCTION: acpi_ns_root_initialize
55 *
56 * PARAMETERS: None
57 *
58 * RETURN: Status
59 *
60 * DESCRIPTION: Allocate and initialize the default root named objects
61 *
62 * MUTEX: Locks namespace for entire execution
63 *
64 ******************************************************************************/
65 acpi_status acpi_ns_root_initialize(void)
66 {
67 acpi_status status;
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;
72
73 ACPI_FUNCTION_TRACE(ns_root_initialize);
74
75 status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
76 if (ACPI_FAILURE(status)) {
77 return_ACPI_STATUS(status);
78 }
79
80 /*
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.
83 */
84 if (acpi_gbl_root_node) {
85 status = AE_OK;
86 goto unlock_and_exit;
87 }
88
89 /*
90 * Tell the rest of the subsystem that the root is initialized
91 * (This is OK because the namespace is locked)
92 */
93 acpi_gbl_root_node = &acpi_gbl_root_node_struct;
94
95 /* Enter the pre-defined names in the name table */
96
97 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
98 "Entering predefined entries into namespace\n"));
99
100 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
101
102 /* _OSI is optional for now, will be permanent later */
103
104 if (!ACPI_STRCMP(init_val->name, "_OSI")
105 && !acpi_gbl_create_osi_method) {
106 continue;
107 }
108
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);
112
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",
116 init_val->name));
117 }
118
119 /*
120 * Name entered successfully.
121 * If entry in pre_defined_names[] specifies an
122 * 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 i_aSL 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.method_flags =
167 AML_METHOD_INTERNAL_ONLY;
168 obj_desc->method.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 /*
181 * Build an object around the static string
182 */
183 obj_desc->string.length =
184 (u32) ACPI_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 (ACPI_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 %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 ACPI_GET_OBJECT_TYPE
237 (obj_desc));
238
239 /* Remove local reference to the object */
240
241 acpi_ut_remove_reference(obj_desc);
242 }
243 }
244
245 unlock_and_exit:
246 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
247
248 /* Save a handle to "_GPE", it is always present */
249
250 if (ACPI_SUCCESS(status)) {
251 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
252 &acpi_gbl_fadt_gpe_device);
253 }
254
255 return_ACPI_STATUS(status);
256 }
257
258 /*******************************************************************************
259 *
260 * FUNCTION: acpi_ns_lookup
261 *
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)
271 *
272 * RETURN: Status
273 *
274 * DESCRIPTION: Find or enter the passed name in the name space.
275 * Log an error if name not found in Exec mode.
276 *
277 * MUTEX: Assumes namespace is locked.
278 *
279 ******************************************************************************/
280
281 acpi_status
282 acpi_ns_lookup(union acpi_generic_state *scope_info,
283 char *pathname,
284 acpi_object_type type,
285 acpi_interpreter_mode interpreter_mode,
286 u32 flags,
287 struct acpi_walk_state *walk_state,
288 struct acpi_namespace_node **return_node)
289 {
290 acpi_status status;
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;
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
303 ACPI_FUNCTION_TRACE(ns_lookup);
304
305 if (!return_node) {
306 return_ACPI_STATUS(AE_BAD_PARAMETER);
307 }
308
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++;
312
313 if (!acpi_gbl_root_node) {
314 return_ACPI_STATUS(AE_NO_NAMESPACE);
315 }
316
317 /*
318 * Get the prefix scope.
319 * A null scope means use the root scope
320 */
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));
325
326 prefix_node = acpi_gbl_root_node;
327 } else {
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]",
332 prefix_node,
333 acpi_ut_get_descriptor_name(prefix_node)));
334 return_ACPI_STATUS(AE_AML_INTERNAL);
335 }
336
337 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
338 /*
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.
342 */
343 while (!acpi_ns_opens_scope(prefix_node->type) &&
344 prefix_node->type != ACPI_TYPE_ANY) {
345 prefix_node =
346 acpi_ns_get_parent_node(prefix_node);
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 * Point past this prefix to the name segment
418 * part or the next Parent Prefix
419 */
420 path++;
421
422 /* Backup to the parent node */
423
424 num_carats++;
425 this_node = acpi_ns_get_parent_node(this_node);
426 if (!this_node) {
427
428 /* Current scope has no parent scope */
429
430 ACPI_ERROR((AE_INFO,
431 "ACPI path has too many parent prefixes (^) - reached beyond root node"));
432 return_ACPI_STATUS(AE_NOT_FOUND);
433 }
434 }
435
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));
441 }
442 }
443
444 /*
445 * Determine the number of ACPI name segments in this pathname.
446 *
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
453 *
454 * Examine the name prefix opcode, if any, to determine the number of
455 * segments.
456 */
457 switch (*path) {
458 case 0:
459 /*
460 * Null name after a root or parent prefixes. We already
461 * have the correct target node and there are no name segments.
462 */
463 num_segments = 0;
464 type = this_node->type;
465
466 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
467 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
468 flags));
469 break;
470
471 case AML_DUAL_NAME_PREFIX:
472
473 /* More than one name_seg, search rules do not apply */
474
475 search_parent_flag = ACPI_NS_NO_UPSEARCH;
476
477 /* Two segments, point to first name segment */
478
479 num_segments = 2;
480 path++;
481
482 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
483 "Dual Pathname (2 segments, Flags=%X)\n",
484 flags));
485 break;
486
487 case AML_MULTI_NAME_PREFIX_OP:
488
489 /* More than one name_seg, search rules do not apply */
490
491 search_parent_flag = ACPI_NS_NO_UPSEARCH;
492
493 /* Extract segment count, point to first name segment */
494
495 path++;
496 num_segments = (u32) (u8) * path;
497 path++;
498
499 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
500 "Multi Pathname (%d Segments, Flags=%X)\n",
501 num_segments, flags));
502 break;
503
504 default:
505 /*
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.
508 */
509 num_segments = 1;
510
511 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
512 "Simple Pathname (1 segment, Flags=%X)\n",
513 flags));
514 break;
515 }
516
517 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
518 }
519
520 /*
521 * Search namespace for each segment of the name. Loop through and
522 * verify (or add to the namespace) each name segment.
523 *
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.)
527 */
528 this_search_type = ACPI_TYPE_ANY;
529 current_node = this_node;
530 while (num_segments && current_node) {
531 num_segments--;
532 if (!num_segments) {
533 /*
534 * This is the last segment, enable typechecking
535 */
536 this_search_type = type;
537
538 /*
539 * Only allow automatic parent search (search rules) if the caller
540 * requested it AND we have a single, non-fully-qualified name_seg
541 */
542 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
543 (flags & ACPI_NS_SEARCH_PARENT)) {
544 local_flags |= ACPI_NS_SEARCH_PARENT;
545 }
546
547 /* Set error flag according to caller */
548
549 if (flags & ACPI_NS_ERROR_IF_FOUND) {
550 local_flags |= ACPI_NS_ERROR_IF_FOUND;
551 }
552 }
553
554 /* Extract one ACPI name from the front of the pathname */
555
556 ACPI_MOVE_32_TO_32(&simple_name, path);
557
558 /* Try to find the single (4 character) ACPI name */
559
560 status =
561 acpi_ns_search_and_enter(simple_name, walk_state,
562 current_node, interpreter_mode,
563 this_search_type, local_flags,
564 &this_node);
565 if (ACPI_FAILURE(status)) {
566 if (status == AE_NOT_FOUND) {
567
568 /* Name not found in ACPI namespace */
569
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 *)&current_node->name,
574 current_node));
575 }
576
577 *return_node = this_node;
578 return_ACPI_STATUS(status);
579 }
580
581 /* More segments to follow? */
582
583 if (num_segments > 0) {
584 /*
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
588 * segments).
589 */
590 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
591 if (!this_node->object) {
592 return_ACPI_STATUS(AE_NOT_EXIST);
593 }
594
595 if (acpi_ns_opens_scope
596 (((struct acpi_namespace_node *)this_node->
597 object)->type)) {
598 this_node =
599 (struct acpi_namespace_node *)
600 this_node->object;
601 }
602 }
603 }
604
605 /* Special handling for the last segment (num_segments == 0) */
606
607 else {
608 /*
609 * Sanity typecheck of the target object:
610 *
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
618 *
619 * Then we have a type mismatch. Just warn and ignore it.
620 */
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)) {
627
628 /* Complain about a type mismatch */
629
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->
634 type),
635 acpi_ut_get_type_name
636 (type_to_check_for)));
637 }
638
639 /*
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.
643 */
644 if (type == ACPI_TYPE_ANY) {
645 type = this_node->type;
646 }
647 }
648
649 /* Point to next name segment and make this node current */
650
651 path += ACPI_NAME_SIZE;
652 current_node = this_node;
653 }
654
655 /*
656 * Always check if we need to open a new scope
657 */
658 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
659 /*
660 * If entry is a type which opens a scope, push the new scope on the
661 * scope stack.
662 */
663 if (acpi_ns_opens_scope(type)) {
664 status =
665 acpi_ds_scope_stack_push(this_node, type,
666 walk_state);
667 if (ACPI_FAILURE(status)) {
668 return_ACPI_STATUS(status);
669 }
670 }
671 }
672
673 *return_node = this_node;
674 return_ACPI_STATUS(AE_OK);
675 }
Support for the Chinese Samsung S3C2440 based development boards