Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
[linux-2.6] / drivers / acpi / namespace / nsaccess.c
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 }