ACPICA: Update all ACPICA copyrights and signons to 2010
[linux-3.10.git] / drivers / acpi / acpica / nsaccess.c
1 /*******************************************************************************
2  *
3  * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2010, 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.extra.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 }