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USB: Allow autosuspend delay to equal 0
[linux-2.6.git] / drivers / acpi / namespace / nsaccess.c
blob57faf598bad8f2fe98055f34589f23a2c341d976
1 /*******************************************************************************
2 *
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2007, R. Byron Moore
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
169 #ifndef ACPI_DUMP_APP
170 obj_desc->method.implementation =
171 acpi_ut_osi_implementation;
172 #endif
173 #endif
174 break;
175
176 case ACPI_TYPE_INTEGER:
177
178 obj_desc->integer.value = ACPI_TO_INTEGER(val);
179 break;
180
181 case ACPI_TYPE_STRING:
182
183 /*
184 * Build an object around the static string
185 */
186 obj_desc->string.length =
187 (u32) ACPI_STRLEN(val);
188 obj_desc->string.pointer = val;
189 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
190 break;
191
192 case ACPI_TYPE_MUTEX:
193
194 obj_desc->mutex.node = new_node;
195 obj_desc->mutex.sync_level =
196 (u8) (ACPI_TO_INTEGER(val) - 1);
197
198 /* Create a mutex */
199
200 status =
201 acpi_os_create_mutex(&obj_desc->mutex.
202 os_mutex);
203 if (ACPI_FAILURE(status)) {
204 acpi_ut_remove_reference(obj_desc);
205 goto unlock_and_exit;
206 }
207
208 /* Special case for ACPI Global Lock */
209
210 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
211 acpi_gbl_global_lock_mutex =
212 obj_desc->mutex.os_mutex;
213
214 /* Create additional counting semaphore for global lock */
215
216 status =
217 acpi_os_create_semaphore(1, 0,
218 &acpi_gbl_global_lock_semaphore);
219 if (ACPI_FAILURE(status)) {
220 acpi_ut_remove_reference
221 (obj_desc);
222 goto unlock_and_exit;
223 }
224 }
225 break;
226
227 default:
228
229 ACPI_ERROR((AE_INFO,
230 "Unsupported initial type value %X",
231 init_val->type));
232 acpi_ut_remove_reference(obj_desc);
233 obj_desc = NULL;
234 continue;
235 }
236
237 /* Store pointer to value descriptor in the Node */
238
239 status = acpi_ns_attach_object(new_node, obj_desc,
240 ACPI_GET_OBJECT_TYPE
241 (obj_desc));
242
243 /* Remove local reference to the object */
244
245 acpi_ut_remove_reference(obj_desc);
246 }
247 }
248
249 unlock_and_exit:
250 (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
251
252 /* Save a handle to "_GPE", it is always present */
253
254 if (ACPI_SUCCESS(status)) {
255 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
256 &acpi_gbl_fadt_gpe_device);
257 }
258
259 return_ACPI_STATUS(status);
260 }
261
262 /*******************************************************************************
263 *
264 * FUNCTION: acpi_ns_lookup
265 *
266 * PARAMETERS: scope_info - Current scope info block
267 * Pathname - Search pathname, in internal format
268 * (as represented in the AML stream)
269 * Type - Type associated with name
270 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
271 * Flags - Flags describing the search restrictions
272 * walk_state - Current state of the walk
273 * return_node - Where the Node is placed (if found
274 * or created successfully)
275 *
276 * RETURN: Status
277 *
278 * DESCRIPTION: Find or enter the passed name in the name space.
279 * Log an error if name not found in Exec mode.
280 *
281 * MUTEX: Assumes namespace is locked.
282 *
283 ******************************************************************************/
284
285 acpi_status
286 acpi_ns_lookup(union acpi_generic_state *scope_info,
287 char *pathname,
288 acpi_object_type type,
289 acpi_interpreter_mode interpreter_mode,
290 u32 flags,
291 struct acpi_walk_state *walk_state,
292 struct acpi_namespace_node **return_node)
293 {
294 acpi_status status;
295 char *path = pathname;
296 struct acpi_namespace_node *prefix_node;
297 struct acpi_namespace_node *current_node = NULL;
298 struct acpi_namespace_node *this_node = NULL;
299 u32 num_segments;
300 u32 num_carats;
301 acpi_name simple_name;
302 acpi_object_type type_to_check_for;
303 acpi_object_type this_search_type;
304 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
305 u32 local_flags;
306
307 ACPI_FUNCTION_TRACE(ns_lookup);
308
309 if (!return_node) {
310 return_ACPI_STATUS(AE_BAD_PARAMETER);
311 }
312
313 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
314 *return_node = ACPI_ENTRY_NOT_FOUND;
315 acpi_gbl_ns_lookup_count++;
316
317 if (!acpi_gbl_root_node) {
318 return_ACPI_STATUS(AE_NO_NAMESPACE);
319 }
320
321 /*
322 * Get the prefix scope.
323 * A null scope means use the root scope
324 */
325 if ((!scope_info) || (!scope_info->scope.node)) {
326 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
327 "Null scope prefix, using root node (%p)\n",
328 acpi_gbl_root_node));
329
330 prefix_node = acpi_gbl_root_node;
331 } else {
332 prefix_node = scope_info->scope.node;
333 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
334 ACPI_DESC_TYPE_NAMED) {
335 ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
336 prefix_node,
337 acpi_ut_get_descriptor_name(prefix_node)));
338 return_ACPI_STATUS(AE_AML_INTERNAL);
339 }
340
341 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
342 /*
343 * This node might not be a actual "scope" node (such as a
344 * Device/Method, etc.) It could be a Package or other object node.
345 * Backup up the tree to find the containing scope node.
346 */
347 while (!acpi_ns_opens_scope(prefix_node->type) &&
348 prefix_node->type != ACPI_TYPE_ANY) {
349 prefix_node =
350 acpi_ns_get_parent_node(prefix_node);
351 }
352 }
353 }
354
355 /* Save type TBD: may be no longer necessary */
356
357 type_to_check_for = type;
358
359 /*
360 * Begin examination of the actual pathname
361 */
362 if (!pathname) {
363
364 /* A Null name_path is allowed and refers to the root */
365
366 num_segments = 0;
367 this_node = acpi_gbl_root_node;
368 path = "";
369
370 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
371 "Null Pathname (Zero segments), Flags=%X\n",
372 flags));
373 } else {
374 /*
375 * Name pointer is valid (and must be in internal name format)
376 *
377 * Check for scope prefixes:
378 *
379 * As represented in the AML stream, a namepath consists of an
380 * optional scope prefix followed by a name segment part.
381 *
382 * If present, the scope prefix is either a Root Prefix (in
383 * which case the name is fully qualified), or one or more
384 * Parent Prefixes (in which case the name's scope is relative
385 * to the current scope).
386 */
387 if (*path == (u8) AML_ROOT_PREFIX) {
388
389 /* Pathname is fully qualified, start from the root */
390
391 this_node = acpi_gbl_root_node;
392 search_parent_flag = ACPI_NS_NO_UPSEARCH;
393
394 /* Point to name segment part */
395
396 path++;
397
398 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
399 "Path is absolute from root [%p]\n",
400 this_node));
401 } else {
402 /* Pathname is relative to current scope, start there */
403
404 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
405 "Searching relative to prefix scope [%4.4s] (%p)\n",
406 acpi_ut_get_node_name(prefix_node),
407 prefix_node));
408
409 /*
410 * Handle multiple Parent Prefixes (carat) by just getting
411 * the parent node for each prefix instance.
412 */
413 this_node = prefix_node;
414 num_carats = 0;
415 while (*path == (u8) AML_PARENT_PREFIX) {
416
417 /* Name is fully qualified, no search rules apply */
418
419 search_parent_flag = ACPI_NS_NO_UPSEARCH;
420 /*
421 * Point past this prefix to the name segment
422 * part or the next Parent Prefix
423 */
424 path++;
425
426 /* Backup to the parent node */
427
428 num_carats++;
429 this_node = acpi_ns_get_parent_node(this_node);
430 if (!this_node) {
431
432 /* Current scope has no parent scope */
433
434 ACPI_ERROR((AE_INFO,
435 "ACPI path has too many parent prefixes (^) - reached beyond root node"));
436 return_ACPI_STATUS(AE_NOT_FOUND);
437 }
438 }
439
440 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
441 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
442 "Search scope is [%4.4s], path has %d carat(s)\n",
443 acpi_ut_get_node_name
444 (this_node), num_carats));
445 }
446 }
447
448 /*
449 * Determine the number of ACPI name segments in this pathname.
450 *
451 * The segment part consists of either:
452 * - A Null name segment (0)
453 * - A dual_name_prefix followed by two 4-byte name segments
454 * - A multi_name_prefix followed by a byte indicating the
455 * number of segments and the segments themselves.
456 * - A single 4-byte name segment
457 *
458 * Examine the name prefix opcode, if any, to determine the number of
459 * segments.
460 */
461 switch (*path) {
462 case 0:
463 /*
464 * Null name after a root or parent prefixes. We already
465 * have the correct target node and there are no name segments.
466 */
467 num_segments = 0;
468 type = this_node->type;
469
470 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
471 "Prefix-only Pathname (Zero name segments), Flags=%X\n",
472 flags));
473 break;
474
475 case AML_DUAL_NAME_PREFIX:
476
477 /* More than one name_seg, search rules do not apply */
478
479 search_parent_flag = ACPI_NS_NO_UPSEARCH;
480
481 /* Two segments, point to first name segment */
482
483 num_segments = 2;
484 path++;
485
486 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
487 "Dual Pathname (2 segments, Flags=%X)\n",
488 flags));
489 break;
490
491 case AML_MULTI_NAME_PREFIX_OP:
492
493 /* More than one name_seg, search rules do not apply */
494
495 search_parent_flag = ACPI_NS_NO_UPSEARCH;
496
497 /* Extract segment count, point to first name segment */
498
499 path++;
500 num_segments = (u32) (u8) * path;
501 path++;
502
503 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
504 "Multi Pathname (%d Segments, Flags=%X)\n",
505 num_segments, flags));
506 break;
507
508 default:
509 /*
510 * Not a Null name, no Dual or Multi prefix, hence there is
511 * only one name segment and Pathname is already pointing to it.
512 */
513 num_segments = 1;
514
515 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
516 "Simple Pathname (1 segment, Flags=%X)\n",
517 flags));
518 break;
519 }
520
521 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
522 }
523
524 /*
525 * Search namespace for each segment of the name. Loop through and
526 * verify (or add to the namespace) each name segment.
527 *
528 * The object type is significant only at the last name
529 * segment. (We don't care about the types along the path, only
530 * the type of the final target object.)
531 */
532 this_search_type = ACPI_TYPE_ANY;
533 current_node = this_node;
534 while (num_segments && current_node) {
535 num_segments--;
536 if (!num_segments) {
537 /*
538 * This is the last segment, enable typechecking
539 */
540 this_search_type = type;
541
542 /*
543 * Only allow automatic parent search (search rules) if the caller
544 * requested it AND we have a single, non-fully-qualified name_seg
545 */
546 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
547 (flags & ACPI_NS_SEARCH_PARENT)) {
548 local_flags |= ACPI_NS_SEARCH_PARENT;
549 }
550
551 /* Set error flag according to caller */
552
553 if (flags & ACPI_NS_ERROR_IF_FOUND) {
554 local_flags |= ACPI_NS_ERROR_IF_FOUND;
555 }
556 }
557
558 /* Extract one ACPI name from the front of the pathname */
559
560 ACPI_MOVE_32_TO_32(&simple_name, path);
561
562 /* Try to find the single (4 character) ACPI name */
563
564 status =
565 acpi_ns_search_and_enter(simple_name, walk_state,
566 current_node, interpreter_mode,
567 this_search_type, local_flags,
568 &this_node);
569 if (ACPI_FAILURE(status)) {
570 if (status == AE_NOT_FOUND) {
571
572 /* Name not found in ACPI namespace */
573
574 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
575 "Name [%4.4s] not found in scope [%4.4s] %p\n",
576 (char *)&simple_name,
577 (char *)&current_node->name,
578 current_node));
579 }
580
581 *return_node = this_node;
582 return_ACPI_STATUS(status);
583 }
584
585 /*
586 * Sanity typecheck of the target object:
587 *
588 * If 1) This is the last segment (num_segments == 0)
589 * 2) And we are looking for a specific type
590 * (Not checking for TYPE_ANY)
591 * 3) Which is not an alias
592 * 4) Which is not a local type (TYPE_SCOPE)
593 * 5) And the type of target object is known (not TYPE_ANY)
594 * 6) And target object does not match what we are looking for
595 *
596 * Then we have a type mismatch. Just warn and ignore it.
597 */
598 if ((num_segments == 0) &&
599 (type_to_check_for != ACPI_TYPE_ANY) &&
600 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
601 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) &&
602 (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) &&
603 (this_node->type != ACPI_TYPE_ANY) &&
604 (this_node->type != type_to_check_for)) {
605
606 /* Complain about a type mismatch */
607
608 ACPI_WARNING((AE_INFO,
609 "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
610 ACPI_CAST_PTR(char, &simple_name),
611 acpi_ut_get_type_name(this_node->type),
612 acpi_ut_get_type_name
613 (type_to_check_for)));
614 }
615
616 /*
617 * If this is the last name segment and we are not looking for a
618 * specific type, but the type of found object is known, use that type
619 * to see if it opens a scope.
620 */
621 if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
622 type = this_node->type;
623 }
624
625 /* Point to next name segment and make this node current */
626
627 path += ACPI_NAME_SIZE;
628 current_node = this_node;
629 }
630
631 /*
632 * Always check if we need to open a new scope
633 */
634 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
635 /*
636 * If entry is a type which opens a scope, push the new scope on the
637 * scope stack.
638 */
639 if (acpi_ns_opens_scope(type)) {
640 status =
641 acpi_ds_scope_stack_push(this_node, type,
642 walk_state);
643 if (ACPI_FAILURE(status)) {
644 return_ACPI_STATUS(status);
645 }
646 }
647 }
648
649 *return_node = this_node;
650 return_ACPI_STATUS(AE_OK);
651 }
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