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On Tue, Nov 06, 2007 at 02:33:53AM -0800, akpm@linux-foundation.org wrote:
[mmotm.git] / drivers / acpi / acpica / nsaccess.c
blob9c3cdbe2d82a96e8b5ed8502432d057afa3e5856
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 "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 ******************************************************************************/
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
114 if (ACPI_FAILURE(status) || (!new_node)) { /* Must be on same line for code converter */
115 ACPI_EXCEPTION((AE_INFO, status,
116 "Could not create predefined name %s",
117 init_val->name));
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 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 /* Build an object around the static string */
181
182 obj_desc->string.length =
183 (u32) ACPI_STRLEN(val);
184 obj_desc->string.pointer = val;
185 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
186 break;
187
188 case ACPI_TYPE_MUTEX:
189
190 obj_desc->mutex.node = new_node;
191 obj_desc->mutex.sync_level =
192 (u8) (ACPI_TO_INTEGER(val) - 1);
193
194 /* Create a mutex */
195
196 status =
197 acpi_os_create_mutex(&obj_desc->mutex.
198 os_mutex);
199 if (ACPI_FAILURE(status)) {
200 acpi_ut_remove_reference(obj_desc);
201 goto unlock_and_exit;
202 }
203
204 /* Special case for ACPI Global Lock */
205
206 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
207 acpi_gbl_global_lock_mutex = obj_desc;
208
209 /* Create additional counting semaphore for global lock */
210
211 status =
212 acpi_os_create_semaphore(1, 0,
213 &acpi_gbl_global_lock_semaphore);
214 if (ACPI_FAILURE(status)) {
215 acpi_ut_remove_reference
216 (obj_desc);
217 goto unlock_and_exit;
218 }
219 }
220 break;
221
222 default:
223
224 ACPI_ERROR((AE_INFO,
225 "Unsupported initial type value %X",
226 init_val->type));
227 acpi_ut_remove_reference(obj_desc);
228 obj_desc = NULL;
229 continue;
230 }
231
232 /* Store pointer to value descriptor in the Node */
233
234 status = acpi_ns_attach_object(new_node, obj_desc,
235 obj_desc->common.type);
236
237 /* Remove local reference to the object */
238
239 acpi_ut_remove_reference(obj_desc);
240 }
241 }
242
243 unlock_and_exit:
244 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
245
246 /* Save a handle to "_GPE", it is always present */
247
248 if (ACPI_SUCCESS(status)) {
249 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
250 &acpi_gbl_fadt_gpe_device);
251 }
252
253 return_ACPI_STATUS(status);
254 }
255
256 /*******************************************************************************
257 *
258 * FUNCTION: acpi_ns_lookup
259 *
260 * PARAMETERS: scope_info - Current scope info block
261 * Pathname - Search pathname, in internal format
262 * (as represented in the AML stream)
263 * Type - Type associated with name
264 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
265 * Flags - Flags describing the search restrictions
266 * walk_state - Current state of the walk
267 * return_node - Where the Node is placed (if found
268 * or created successfully)
269 *
270 * RETURN: Status
271 *
272 * DESCRIPTION: Find or enter the passed name in the name space.
273 * Log an error if name not found in Exec mode.
274 *
275 * MUTEX: Assumes namespace is locked.
276 *
277 ******************************************************************************/
278
279 acpi_status
280 acpi_ns_lookup(union acpi_generic_state *scope_info,
281 char *pathname,
282 acpi_object_type type,
283 acpi_interpreter_mode interpreter_mode,
284 u32 flags,
285 struct acpi_walk_state *walk_state,
286 struct acpi_namespace_node **return_node)
287 {
288 acpi_status status;
289 char *path = pathname;
290 struct acpi_namespace_node *prefix_node;
291 struct acpi_namespace_node *current_node = NULL;
292 struct acpi_namespace_node *this_node = NULL;
293 u32 num_segments;
294 u32 num_carats;
295 acpi_name simple_name;
296 acpi_object_type type_to_check_for;
297 acpi_object_type this_search_type;
298 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
299 u32 local_flags;
300
301 ACPI_FUNCTION_TRACE(ns_lookup);
302
303 if (!return_node) {
304 return_ACPI_STATUS(AE_BAD_PARAMETER);
305 }
306
307 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
308 *return_node = ACPI_ENTRY_NOT_FOUND;
309 acpi_gbl_ns_lookup_count++;
310
311 if (!acpi_gbl_root_node) {
312 return_ACPI_STATUS(AE_NO_NAMESPACE);
313 }
314
315 /* Get the prefix scope. A null scope means use the root scope */
316
317 if ((!scope_info) || (!scope_info->scope.node)) {
318 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
319 "Null scope prefix, using root node (%p)\n",
320 acpi_gbl_root_node));
321
322 prefix_node = acpi_gbl_root_node;
323 } else {
324 prefix_node = scope_info->scope.node;
325 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
326 ACPI_DESC_TYPE_NAMED) {
327 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
328 prefix_node,
329 acpi_ut_get_descriptor_name(prefix_node)));
330 return_ACPI_STATUS(AE_AML_INTERNAL);
331 }
332
333 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
334 /*
335 * This node might not be a actual "scope" node (such as a
336 * Device/Method, etc.) It could be a Package or other object
337 * node. Backup up the tree to find the containing scope node.
338 */
339 while (!acpi_ns_opens_scope(prefix_node->type) &&
340 prefix_node->type != ACPI_TYPE_ANY) {
341 prefix_node =
342 acpi_ns_get_parent_node(prefix_node);
343 }
344 }
345 }
346
347 /* Save type. TBD: may be no longer necessary */
348
349 type_to_check_for = type;
350
351 /*
352 * Begin examination of the actual pathname
353 */
354 if (!pathname) {
355
356 /* A Null name_path is allowed and refers to the root */
357
358 num_segments = 0;
359 this_node = acpi_gbl_root_node;
360 path = "";
361
362 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
363 "Null Pathname (Zero segments), Flags=%X\n",
364 flags));
365 } else {
366 /*
367 * Name pointer is valid (and must be in internal name format)
368 *
369 * Check for scope prefixes:
370 *
371 * As represented in the AML stream, a namepath consists of an
372 * optional scope prefix followed by a name segment part.
373 *
374 * If present, the scope prefix is either a Root Prefix (in
375 * which case the name is fully qualified), or one or more
376 * Parent Prefixes (in which case the name's scope is relative
377 * to the current scope).
378 */
379 if (*path == (u8) AML_ROOT_PREFIX) {
380
381 /* Pathname is fully qualified, start from the root */
382
383 this_node = acpi_gbl_root_node;
384 search_parent_flag = ACPI_NS_NO_UPSEARCH;
385
386 /* Point to name segment part */
387
388 path++;
389
390 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
391 "Path is absolute from root [%p]\n",
392 this_node));
393 } else {
394 /* Pathname is relative to current scope, start there */
395
396 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
397 "Searching relative to prefix scope [%4.4s] (%p)\n",
398 acpi_ut_get_node_name(prefix_node),
399 prefix_node));
400
401 /*
402 * Handle multiple Parent Prefixes (carat) by just getting
403 * the parent node for each prefix instance.
404 */
405 this_node = prefix_node;
406 num_carats = 0;
407 while (*path == (u8) AML_PARENT_PREFIX) {
408
409 /* Name is fully qualified, no search rules apply */
410
411 search_parent_flag = ACPI_NS_NO_UPSEARCH;
412
413 /*
414 * Point past this prefix to the name segment
415 * part or the next Parent Prefix
416 */
417 path++;
418
419 /* Backup to the parent node */
420
421 num_carats++;
422 this_node = acpi_ns_get_parent_node(this_node);
423 if (!this_node) {
424
425 /* Current scope has no parent scope */
426
427 ACPI_ERROR((AE_INFO,
428 "ACPI path has too many parent prefixes (^) "
429 "- reached beyond root node"));
430 return_ACPI_STATUS(AE_NOT_FOUND);
431 }
432 }
433
434 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
435 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
436 "Search scope is [%4.4s], path has %d carat(s)\n",
437 acpi_ut_get_node_name
438 (this_node), num_carats));
439 }
440 }
441
442 /*
443 * Determine the number of ACPI name segments in this pathname.
444 *
445 * The segment part consists of either:
446 * - A Null name segment (0)
447 * - A dual_name_prefix followed by two 4-byte name segments
448 * - A multi_name_prefix followed by a byte indicating the
449 * number of segments and the segments themselves.
450 * - A single 4-byte name segment
451 *
452 * Examine the name prefix opcode, if any, to determine the number of
453 * segments.
454 */
455 switch (*path) {
456 case 0:
457 /*
458 * Null name after a root or parent prefixes. We already
459 * have the correct target node and there are no name segments.
460 */
461 num_segments = 0;
462 type = this_node->type;
463
464 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
465 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
466 flags));
467 break;
468
469 case AML_DUAL_NAME_PREFIX:
470
471 /* More than one name_seg, search rules do not apply */
472
473 search_parent_flag = ACPI_NS_NO_UPSEARCH;
474
475 /* Two segments, point to first name segment */
476
477 num_segments = 2;
478 path++;
479
480 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
481 "Dual Pathname (2 segments, Flags=%X)\n",
482 flags));
483 break;
484
485 case AML_MULTI_NAME_PREFIX_OP:
486
487 /* More than one name_seg, search rules do not apply */
488
489 search_parent_flag = ACPI_NS_NO_UPSEARCH;
490
491 /* Extract segment count, point to first name segment */
492
493 path++;
494 num_segments = (u32) (u8) * path;
495 path++;
496
497 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
498 "Multi Pathname (%d Segments, Flags=%X)\n",
499 num_segments, flags));
500 break;
501
502 default:
503 /*
504 * Not a Null name, no Dual or Multi prefix, hence there is
505 * only one name segment and Pathname is already pointing to it.
506 */
507 num_segments = 1;
508
509 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
510 "Simple Pathname (1 segment, Flags=%X)\n",
511 flags));
512 break;
513 }
514
515 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
516 }
517
518 /*
519 * Search namespace for each segment of the name. Loop through and
520 * verify (or add to the namespace) each name segment.
521 *
522 * The object type is significant only at the last name
523 * segment. (We don't care about the types along the path, only
524 * the type of the final target object.)
525 */
526 this_search_type = ACPI_TYPE_ANY;
527 current_node = this_node;
528 while (num_segments && current_node) {
529 num_segments--;
530 if (!num_segments) {
531
532 /* This is the last segment, enable typechecking */
533
534 this_search_type = type;
535
536 /*
537 * Only allow automatic parent search (search rules) if the caller
538 * requested it AND we have a single, non-fully-qualified name_seg
539 */
540 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
541 (flags & ACPI_NS_SEARCH_PARENT)) {
542 local_flags |= ACPI_NS_SEARCH_PARENT;
543 }
544
545 /* Set error flag according to caller */
546
547 if (flags & ACPI_NS_ERROR_IF_FOUND) {
548 local_flags |= ACPI_NS_ERROR_IF_FOUND;
549 }
550 }
551
552 /* Extract one ACPI name from the front of the pathname */
553
554 ACPI_MOVE_32_TO_32(&simple_name, path);
555
556 /* Try to find the single (4 character) ACPI name */
557
558 status =
559 acpi_ns_search_and_enter(simple_name, walk_state,
560 current_node, interpreter_mode,
561 this_search_type, local_flags,
562 &this_node);
563 if (ACPI_FAILURE(status)) {
564 if (status == AE_NOT_FOUND) {
565
566 /* Name not found in ACPI namespace */
567
568 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
569 "Name [%4.4s] not found in scope [%4.4s] %p\n",
570 (char *)&simple_name,
571 (char *)&current_node->name,
572 current_node));
573 }
574
575 *return_node = this_node;
576 return_ACPI_STATUS(status);
577 }
578
579 /* More segments to follow? */
580
581 if (num_segments > 0) {
582 /*
583 * If we have an alias to an object that opens a scope (such as a
584 * device or processor), we need to dereference the alias here so
585 * that we can access any children of the original node (via the
586 * remaining segments).
587 */
588 if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
589 if (!this_node->object) {
590 return_ACPI_STATUS(AE_NOT_EXIST);
591 }
592
593 if (acpi_ns_opens_scope
594 (((struct acpi_namespace_node *)
595 this_node->object)->type)) {
596 this_node =
597 (struct acpi_namespace_node *)
598 this_node->object;
599 }
600 }
601 }
602
603 /* Special handling for the last segment (num_segments == 0) */
604
605 else {
606 /*
607 * Sanity typecheck of the target object:
608 *
609 * If 1) This is the last segment (num_segments == 0)
610 * 2) And we are looking for a specific type
611 * (Not checking for TYPE_ANY)
612 * 3) Which is not an alias
613 * 4) Which is not a local type (TYPE_SCOPE)
614 * 5) And the type of target object is known (not TYPE_ANY)
615 * 6) And target object does not match what we are looking for
616 *
617 * Then we have a type mismatch. Just warn and ignore it.
618 */
619 if ((type_to_check_for != ACPI_TYPE_ANY) &&
620 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
621 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
622 && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
623 && (this_node->type != ACPI_TYPE_ANY)
624 && (this_node->type != type_to_check_for)) {
625
626 /* Complain about a type mismatch */
627
628 ACPI_WARNING((AE_INFO,
629 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
630 ACPI_CAST_PTR(char, &simple_name),
631 acpi_ut_get_type_name(this_node->
632 type),
633 acpi_ut_get_type_name
634 (type_to_check_for)));
635 }
636
637 /*
638 * If this is the last name segment and we are not looking for a
639 * specific type, but the type of found object is known, use that
640 * type to (later) see if it opens a scope.
641 */
642 if (type == ACPI_TYPE_ANY) {
643 type = this_node->type;
644 }
645 }
646
647 /* Point to next name segment and make this node current */
648
649 path += ACPI_NAME_SIZE;
650 current_node = this_node;
651 }
652
653 /* Always check if we need to open a new scope */
654
655 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
656 /*
657 * If entry is a type which opens a scope, push the new scope on the
658 * scope stack.
659 */
660 if (acpi_ns_opens_scope(type)) {
661 status =
662 acpi_ds_scope_stack_push(this_node, type,
663 walk_state);
664 if (ACPI_FAILURE(status)) {
665 return_ACPI_STATUS(status);
666 }
667 }
668 }
669
670 *return_node = this_node;
671 return_ACPI_STATUS(AE_OK);
672 }
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