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Linux-2.6.12-rc2
[linux-2.6/kvm.git] / drivers / acpi / namespace / nsaccess.c
blob1c0c12336c57335cdc5fa6bf489570a2c96c5183
1 /*******************************************************************************
2 *
3 * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
4 *
5 ******************************************************************************/
6
7 /*
8 * Copyright (C) 2000 - 2005, 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
45 #include <acpi/acpi.h>
46 #include <acpi/amlcode.h>
47 #include <acpi/acnamesp.h>
48 #include <acpi/acdispat.h>
49
50
51 #define _COMPONENT ACPI_NAMESPACE
52 ACPI_MODULE_NAME ("nsaccess")
53
54
55 /*******************************************************************************
56 *
57 * FUNCTION: acpi_ns_root_initialize
58 *
59 * PARAMETERS: None
60 *
61 * RETURN: Status
62 *
63 * DESCRIPTION: Allocate and initialize the default root named objects
64 *
65 * MUTEX: Locks namespace for entire execution
66 *
67 ******************************************************************************/
68
69 acpi_status
70 acpi_ns_root_initialize (void)
71 {
72 acpi_status status;
73 const struct acpi_predefined_names *init_val = NULL;
74 struct acpi_namespace_node *new_node;
75 union acpi_operand_object *obj_desc;
76 acpi_string val = NULL;
77
78
79 ACPI_FUNCTION_TRACE ("ns_root_initialize");
80
81
82 status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
83 if (ACPI_FAILURE (status)) {
84 return_ACPI_STATUS (status);
85 }
86
87 /*
88 * The global root ptr is initially NULL, so a non-NULL value indicates
89 * that acpi_ns_root_initialize() has already been called; just return.
90 */
91 if (acpi_gbl_root_node) {
92 status = AE_OK;
93 goto unlock_and_exit;
94 }
95
96 /*
97 * Tell the rest of the subsystem that the root is initialized
98 * (This is OK because the namespace is locked)
99 */
100 acpi_gbl_root_node = &acpi_gbl_root_node_struct;
101
102 /* Enter the pre-defined names in the name table */
103
104 ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
105 "Entering predefined entries into namespace\n"));
106
107 for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
108 /* _OSI is optional for now, will be permanent later */
109
110 if (!ACPI_STRCMP (init_val->name, "_OSI") && !acpi_gbl_create_osi_method) {
111 continue;
112 }
113
114 status = acpi_ns_lookup (NULL, init_val->name, init_val->type,
115 ACPI_IMODE_LOAD_PASS2, ACPI_NS_NO_UPSEARCH,
116 NULL, &new_node);
117
118 if (ACPI_FAILURE (status) || (!new_node)) /* Must be on same line for code converter */ {
119 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
120 "Could not create predefined name %s, %s\n",
121 init_val->name, acpi_format_exception (status)));
122 }
123
124 /*
125 * Name entered successfully.
126 * If entry in pre_defined_names[] specifies an
127 * initial value, create the initial value.
128 */
129 if (init_val->val) {
130 status = acpi_os_predefined_override (init_val, &val);
131 if (ACPI_FAILURE (status)) {
132 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
133 "Could not override predefined %s\n",
134 init_val->name));
135 }
136
137 if (!val) {
138 val = init_val->val;
139 }
140
141 /*
142 * Entry requests an initial value, allocate a
143 * descriptor for it.
144 */
145 obj_desc = acpi_ut_create_internal_object (init_val->type);
146 if (!obj_desc) {
147 status = AE_NO_MEMORY;
148 goto unlock_and_exit;
149 }
150
151 /*
152 * Convert value string from table entry to
153 * internal representation. Only types actually
154 * used for initial values are implemented here.
155 */
156 switch (init_val->type) {
157 case ACPI_TYPE_METHOD:
158 obj_desc->method.param_count = (u8) ACPI_TO_INTEGER (val);
159 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
160
161 #if defined (_ACPI_ASL_COMPILER) || defined (_ACPI_DUMP_App)
162
163 /*
164 * i_aSL Compiler cheats by putting parameter count
165 * in the owner_iD
166 */
167 new_node->owner_id = obj_desc->method.param_count;
168 #else
169 /* Mark this as a very SPECIAL method */
170
171 obj_desc->method.method_flags = AML_METHOD_INTERNAL_ONLY;
172 obj_desc->method.implementation = acpi_ut_osi_implementation;
173 #endif
174 break;
175
176 case ACPI_TYPE_INTEGER:
177
178 obj_desc->integer.value = ACPI_TO_INTEGER (val);
179 break;
180
181
182 case ACPI_TYPE_STRING:
183
184 /*
185 * Build an object around the static string
186 */
187 obj_desc->string.length = (u32) ACPI_STRLEN (val);
188 obj_desc->string.pointer = val;
189 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
190 break;
191
192
193 case ACPI_TYPE_MUTEX:
194
195 obj_desc->mutex.node = new_node;
196 obj_desc->mutex.sync_level = (u8) (ACPI_TO_INTEGER (val) - 1);
197
198 if (ACPI_STRCMP (init_val->name, "_GL_") == 0) {
199 /*
200 * Create a counting semaphore for the
201 * global lock
202 */
203 status = acpi_os_create_semaphore (ACPI_NO_UNIT_LIMIT,
204 1, &obj_desc->mutex.semaphore);
205 if (ACPI_FAILURE (status)) {
206 acpi_ut_remove_reference (obj_desc);
207 goto unlock_and_exit;
208 }
209
210 /*
211 * We just created the mutex for the
212 * global lock, save it
213 */
214 acpi_gbl_global_lock_semaphore = obj_desc->mutex.semaphore;
215 }
216 else {
217 /* Create a mutex */
218
219 status = acpi_os_create_semaphore (1, 1,
220 &obj_desc->mutex.semaphore);
221 if (ACPI_FAILURE (status)) {
222 acpi_ut_remove_reference (obj_desc);
223 goto unlock_and_exit;
224 }
225 }
226 break;
227
228
229 default:
230
231 ACPI_REPORT_ERROR (("Unsupported initial type value %X\n",
232 init_val->type));
233 acpi_ut_remove_reference (obj_desc);
234 obj_desc = NULL;
235 continue;
236 }
237
238 /* Store pointer to value descriptor in the Node */
239
240 status = acpi_ns_attach_object (new_node, obj_desc,
241 ACPI_GET_OBJECT_TYPE (obj_desc));
242
243 /* Remove local reference to the object */
244
245 acpi_ut_remove_reference (obj_desc);
246 }
247 }
248
249
250 unlock_and_exit:
251 (void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
252
253 /* Save a handle to "_GPE", it is always present */
254
255 if (ACPI_SUCCESS (status)) {
256 status = acpi_ns_get_node_by_path ("\\_GPE", NULL, ACPI_NS_NO_UPSEARCH,
257 &acpi_gbl_fadt_gpe_device);
258 }
259
260 return_ACPI_STATUS (status);
261 }
262
263
264 /*******************************************************************************
265 *
266 * FUNCTION: acpi_ns_lookup
267 *
268 * PARAMETERS: prefix_node - Search scope if name is not fully qualified
269 * Pathname - Search pathname, in internal format
270 * (as represented in the AML stream)
271 * Type - Type associated with name
272 * interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
273 * Flags - Flags describing the search restrictions
274 * walk_state - Current state of the walk
275 * return_node - Where the Node is placed (if found
276 * or created successfully)
277 *
278 * RETURN: Status
279 *
280 * DESCRIPTION: Find or enter the passed name in the name space.
281 * Log an error if name not found in Exec mode.
282 *
283 * MUTEX: Assumes namespace is locked.
284 *
285 ******************************************************************************/
286
287 acpi_status
288 acpi_ns_lookup (
289 union acpi_generic_state *scope_info,
290 char *pathname,
291 acpi_object_type type,
292 acpi_interpreter_mode interpreter_mode,
293 u32 flags,
294 struct acpi_walk_state *walk_state,
295 struct acpi_namespace_node **return_node)
296 {
297 acpi_status status;
298 char *path = pathname;
299 struct acpi_namespace_node *prefix_node;
300 struct acpi_namespace_node *current_node = NULL;
301 struct acpi_namespace_node *this_node = NULL;
302 u32 num_segments;
303 u32 num_carats;
304 acpi_name simple_name;
305 acpi_object_type type_to_check_for;
306 acpi_object_type this_search_type;
307 u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
308 u32 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND |
309 ACPI_NS_SEARCH_PARENT);
310
311
312 ACPI_FUNCTION_TRACE ("ns_lookup");
313
314
315 if (!return_node) {
316 return_ACPI_STATUS (AE_BAD_PARAMETER);
317 }
318
319 acpi_gbl_ns_lookup_count++;
320 *return_node = ACPI_ENTRY_NOT_FOUND;
321
322 if (!acpi_gbl_root_node) {
323 return_ACPI_STATUS (AE_NO_NAMESPACE);
324 }
325
326 /*
327 * Get the prefix scope.
328 * A null scope means use the root scope
329 */
330 if ((!scope_info) ||
331 (!scope_info->scope.node)) {
332 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
333 "Null scope prefix, using root node (%p)\n",
334 acpi_gbl_root_node));
335
336 prefix_node = acpi_gbl_root_node;
337 }
338 else {
339 prefix_node = scope_info->scope.node;
340 if (ACPI_GET_DESCRIPTOR_TYPE (prefix_node) != ACPI_DESC_TYPE_NAMED) {
341 ACPI_REPORT_ERROR (("ns_lookup: %p is not a namespace node [%s]\n",
342 prefix_node, acpi_ut_get_descriptor_name (prefix_node)));
343 return_ACPI_STATUS (AE_AML_INTERNAL);
344 }
345
346 /*
347 * This node might not be a actual "scope" node (such as a
348 * Device/Method, etc.) It could be a Package or other object node.
349 * Backup up the tree to find the containing scope node.
350 */
351 while (!acpi_ns_opens_scope (prefix_node->type) &&
352 prefix_node->type != ACPI_TYPE_ANY) {
353 prefix_node = acpi_ns_get_parent_node (prefix_node);
354 }
355 }
356
357 /* Save type TBD: may be no longer necessary */
358
359 type_to_check_for = type;
360
361 /*
362 * Begin examination of the actual pathname
363 */
364 if (!pathname) {
365 /* A Null name_path is allowed and refers to the root */
366
367 num_segments = 0;
368 this_node = acpi_gbl_root_node;
369 path = "";
370
371 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
372 "Null Pathname (Zero segments), Flags=%X\n", flags));
373 }
374 else {
375 /*
376 * Name pointer is valid (and must be in internal name format)
377 *
378 * Check for scope prefixes:
379 *
380 * As represented in the AML stream, a namepath consists of an
381 * optional scope prefix followed by a name segment part.
382 *
383 * If present, the scope prefix is either a Root Prefix (in
384 * which case the name is fully qualified), or one or more
385 * Parent Prefixes (in which case the name's scope is relative
386 * to the current scope).
387 */
388 if (*path == (u8) AML_ROOT_PREFIX) {
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", this_node));
400 }
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), prefix_node));
407
408 /*
409 * Handle multiple Parent Prefixes (carat) by just getting
410 * the parent node for each prefix instance.
411 */
412 this_node = prefix_node;
413 num_carats = 0;
414 while (*path == (u8) AML_PARENT_PREFIX) {
415 /* Name is fully qualified, no search rules apply */
416
417 search_parent_flag = ACPI_NS_NO_UPSEARCH;
418 /*
419 * Point past this prefix to the name segment
420 * part or the next Parent Prefix
421 */
422 path++;
423
424 /* Backup to the parent node */
425
426 num_carats++;
427 this_node = acpi_ns_get_parent_node (this_node);
428 if (!this_node) {
429 /* Current scope has no parent scope */
430
431 ACPI_REPORT_ERROR (
432 ("ACPI path has too many parent prefixes (^) - reached beyond root node\n"));
433 return_ACPI_STATUS (AE_NOT_FOUND);
434 }
435 }
436
437 if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
438 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
439 "Search scope is [%4.4s], path has %d carat(s)\n",
440 acpi_ut_get_node_name (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", flags));
484 break;
485
486 case AML_MULTI_NAME_PREFIX_OP:
487
488 /* More than one name_seg, search rules do not apply */
489
490 search_parent_flag = ACPI_NS_NO_UPSEARCH;
491
492 /* Extract segment count, point to first name segment */
493
494 path++;
495 num_segments = (u32) (u8) *path;
496 path++;
497
498 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
499 "Multi Pathname (%d Segments, Flags=%X) \n",
500 num_segments, flags));
501 break;
502
503 default:
504 /*
505 * Not a Null name, no Dual or Multi prefix, hence there is
506 * only one name segment and Pathname is already pointing to it.
507 */
508 num_segments = 1;
509
510 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
511 "Simple Pathname (1 segment, Flags=%X)\n", flags));
512 break;
513 }
514
515 ACPI_DEBUG_EXEC (acpi_ns_print_pathname (num_segments, path));
516 }
517
518
519 /*
520 * Search namespace for each segment of the name. Loop through and
521 * verify (or add to the namespace) each name segment.
522 *
523 * The object type is significant only at the last name
524 * segment. (We don't care about the types along the path, only
525 * the type of the final target object.)
526 */
527 this_search_type = ACPI_TYPE_ANY;
528 current_node = this_node;
529 while (num_segments && current_node) {
530 num_segments--;
531 if (!num_segments) {
532 /*
533 * This is the last segment, enable typechecking
534 */
535 this_search_type = type;
536
537 /*
538 * Only allow automatic parent search (search rules) if the caller
539 * requested it AND we have a single, non-fully-qualified name_seg
540 */
541 if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
542 (flags & ACPI_NS_SEARCH_PARENT)) {
543 local_flags |= ACPI_NS_SEARCH_PARENT;
544 }
545
546 /* Set error flag according to caller */
547
548 if (flags & ACPI_NS_ERROR_IF_FOUND) {
549 local_flags |= ACPI_NS_ERROR_IF_FOUND;
550 }
551 }
552
553 /* Extract one ACPI name from the front of the pathname */
554
555 ACPI_MOVE_32_TO_32 (&simple_name, path);
556
557 /* Try to find the single (4 character) ACPI name */
558
559 status = acpi_ns_search_and_enter (simple_name, walk_state, current_node,
560 interpreter_mode, this_search_type, local_flags, &this_node);
561 if (ACPI_FAILURE (status)) {
562 if (status == AE_NOT_FOUND) {
563 /* Name not found in ACPI namespace */
564
565 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
566 "Name [%4.4s] not found in scope [%4.4s] %p\n",
567 (char *) &simple_name, (char *) &current_node->name,
568 current_node));
569 }
570
571 *return_node = this_node;
572 return_ACPI_STATUS (status);
573 }
574
575 /*
576 * Sanity typecheck of the target object:
577 *
578 * If 1) This is the last segment (num_segments == 0)
579 * 2) And we are looking for a specific type
580 * (Not checking for TYPE_ANY)
581 * 3) Which is not an alias
582 * 4) Which is not a local type (TYPE_SCOPE)
583 * 5) And the type of target object is known (not TYPE_ANY)
584 * 6) And target object does not match what we are looking for
585 *
586 * Then we have a type mismatch. Just warn and ignore it.
587 */
588 if ((num_segments == 0) &&
589 (type_to_check_for != ACPI_TYPE_ANY) &&
590 (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
591 (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) &&
592 (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) &&
593 (this_node->type != ACPI_TYPE_ANY) &&
594 (this_node->type != type_to_check_for)) {
595 /* Complain about a type mismatch */
596
597 ACPI_REPORT_WARNING (
598 ("ns_lookup: Type mismatch on %4.4s (%s), searching for (%s)\n",
599 (char *) &simple_name, acpi_ut_get_type_name (this_node->type),
600 acpi_ut_get_type_name (type_to_check_for)));
601 }
602
603 /*
604 * If this is the last name segment and we are not looking for a
605 * specific type, but the type of found object is known, use that type
606 * to see if it opens a scope.
607 */
608 if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
609 type = this_node->type;
610 }
611
612 /* Point to next name segment and make this node current */
613
614 path += ACPI_NAME_SIZE;
615 current_node = this_node;
616 }
617
618 /*
619 * Always check if we need to open a new scope
620 */
621 if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
622 /*
623 * If entry is a type which opens a scope, push the new scope on the
624 * scope stack.
625 */
626 if (acpi_ns_opens_scope (type)) {
627 status = acpi_ds_scope_stack_push (this_node, type, walk_state);
628 if (ACPI_FAILURE (status)) {
629 return_ACPI_STATUS (status);
630 }
631 }
632 }
633
634 *return_node = this_node;
635 return_ACPI_STATUS (AE_OK);
636 }
637
kernel-based virtual machine