6923059ba3c7e5cef1ad748250b91f06245425a0
[linux-2.6.git] / 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 - 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 #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                 /* _OSI is optional for now, will be permanent later */
102
103                 if (!ACPI_STRCMP(init_val->name, "_OSI")
104                     && !acpi_gbl_create_osi_method) {
105                         continue;
106                 }
107
108                 status = acpi_ns_lookup(NULL, init_val->name, init_val->type,
109                                         ACPI_IMODE_LOAD_PASS2,
110                                         ACPI_NS_NO_UPSEARCH, NULL, &new_node);
111
112                 if (ACPI_FAILURE(status) || (!new_node)) {      /* Must be on same line for code converter */
113                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
114                                           "Could not create predefined name %s, %s\n",
115                                           init_val->name,
116                                           acpi_format_exception(status)));
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_DEBUG_PRINT((ACPI_DB_ERROR,
128                                                   "Could not override predefined %s\n",
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                                 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
199                                         /*
200                                          * Create a counting semaphore for the
201                                          * global lock
202                                          */
203                                         status =
204                                             acpi_os_create_semaphore
205                                             (ACPI_NO_UNIT_LIMIT, 1,
206                                              &obj_desc->mutex.semaphore);
207                                         if (ACPI_FAILURE(status)) {
208                                                 acpi_ut_remove_reference
209                                                     (obj_desc);
210                                                 goto unlock_and_exit;
211                                         }
212
213                                         /*
214                                          * We just created the mutex for the
215                                          * global lock, save it
216                                          */
217                                         acpi_gbl_global_lock_semaphore =
218                                             obj_desc->mutex.semaphore;
219                                 } else {
220                                         /* Create a mutex */
221
222                                         status = acpi_os_create_semaphore(1, 1,
223                                                                           &obj_desc->
224                                                                           mutex.
225                                                                           semaphore);
226                                         if (ACPI_FAILURE(status)) {
227                                                 acpi_ut_remove_reference
228                                                     (obj_desc);
229                                                 goto unlock_and_exit;
230                                         }
231                                 }
232                                 break;
233
234                         default:
235
236                                 ACPI_REPORT_ERROR(("Unsupported initial type value %X\n", init_val->type));
237                                 acpi_ut_remove_reference(obj_desc);
238                                 obj_desc = NULL;
239                                 continue;
240                         }
241
242                         /* Store pointer to value descriptor in the Node */
243
244                         status = acpi_ns_attach_object(new_node, obj_desc,
245                                                        ACPI_GET_OBJECT_TYPE
246                                                        (obj_desc));
247
248                         /* Remove local reference to the object */
249
250                         acpi_ut_remove_reference(obj_desc);
251                 }
252         }
253
254       unlock_and_exit:
255         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
256
257         /* Save a handle to "_GPE", it is always present */
258
259         if (ACPI_SUCCESS(status)) {
260                 status =
261                     acpi_ns_get_node_by_path("\\_GPE", NULL,
262                                              ACPI_NS_NO_UPSEARCH,
263                                              &acpi_gbl_fadt_gpe_device);
264         }
265
266         return_ACPI_STATUS(status);
267 }
268
269 /*******************************************************************************
270  *
271  * FUNCTION:    acpi_ns_lookup
272  *
273  * PARAMETERS:  scope_info      - Current scope info block
274  *              Pathname        - Search pathname, in internal format
275  *                                (as represented in the AML stream)
276  *              Type            - Type associated with name
277  *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
278  *              Flags           - Flags describing the search restrictions
279  *              walk_state      - Current state of the walk
280  *              return_node     - Where the Node is placed (if found
281  *                                or created successfully)
282  *
283  * RETURN:      Status
284  *
285  * DESCRIPTION: Find or enter the passed name in the name space.
286  *              Log an error if name not found in Exec mode.
287  *
288  * MUTEX:       Assumes namespace is locked.
289  *
290  ******************************************************************************/
291
292 acpi_status
293 acpi_ns_lookup(union acpi_generic_state *scope_info,
294                char *pathname,
295                acpi_object_type type,
296                acpi_interpreter_mode interpreter_mode,
297                u32 flags,
298                struct acpi_walk_state *walk_state,
299                struct acpi_namespace_node **return_node)
300 {
301         acpi_status status;
302         char *path = pathname;
303         struct acpi_namespace_node *prefix_node;
304         struct acpi_namespace_node *current_node = NULL;
305         struct acpi_namespace_node *this_node = NULL;
306         u32 num_segments;
307         u32 num_carats;
308         acpi_name simple_name;
309         acpi_object_type type_to_check_for;
310         acpi_object_type this_search_type;
311         u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
312         u32 local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND |
313                                     ACPI_NS_SEARCH_PARENT);
314
315         ACPI_FUNCTION_TRACE("ns_lookup");
316
317         if (!return_node) {
318                 return_ACPI_STATUS(AE_BAD_PARAMETER);
319         }
320
321         acpi_gbl_ns_lookup_count++;
322         *return_node = ACPI_ENTRY_NOT_FOUND;
323
324         if (!acpi_gbl_root_node) {
325                 return_ACPI_STATUS(AE_NO_NAMESPACE);
326         }
327
328         /*
329          * Get the prefix scope.
330          * A null scope means use the root scope
331          */
332         if ((!scope_info) || (!scope_info->scope.node)) {
333                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
334                                   "Null scope prefix, using root node (%p)\n",
335                                   acpi_gbl_root_node));
336
337                 prefix_node = acpi_gbl_root_node;
338         } else {
339                 prefix_node = scope_info->scope.node;
340                 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
341                     ACPI_DESC_TYPE_NAMED) {
342                         ACPI_REPORT_ERROR(("ns_lookup: %p is not a namespace node [%s]\n", 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",
373                                   flags));
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",
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                                 /* Name is fully qualified, no search rules apply */
417
418                                 search_parent_flag = ACPI_NS_NO_UPSEARCH;
419                                 /*
420                                  * Point past this prefix to the name segment
421                                  * part or the next Parent Prefix
422                                  */
423                                 path++;
424
425                                 /* Backup to the parent node */
426
427                                 num_carats++;
428                                 this_node = acpi_ns_get_parent_node(this_node);
429                                 if (!this_node) {
430                                         /* Current scope has no parent scope */
431
432                                         ACPI_REPORT_ERROR(("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
441                                                   (this_node), num_carats));
442                         }
443                 }
444
445                 /*
446                  * Determine the number of ACPI name segments in this pathname.
447                  *
448                  * The segment part consists of either:
449                  *  - A Null name segment (0)
450                  *  - A dual_name_prefix followed by two 4-byte name segments
451                  *  - A multi_name_prefix followed by a byte indicating the
452                  *      number of segments and the segments themselves.
453                  *  - A single 4-byte name segment
454                  *
455                  * Examine the name prefix opcode, if any, to determine the number of
456                  * segments.
457                  */
458                 switch (*path) {
459                 case 0:
460                         /*
461                          * Null name after a root or parent prefixes. We already
462                          * have the correct target node and there are no name segments.
463                          */
464                         num_segments = 0;
465                         type = this_node->type;
466
467                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
468                                           "Prefix-only Pathname (Zero name segments), Flags=%X\n",
469                                           flags));
470                         break;
471
472                 case AML_DUAL_NAME_PREFIX:
473
474                         /* More than one name_seg, search rules do not apply */
475
476                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
477
478                         /* Two segments, point to first name segment */
479
480                         num_segments = 2;
481                         path++;
482
483                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
484                                           "Dual Pathname (2 segments, Flags=%X)\n",
485                                           flags));
486                         break;
487
488                 case AML_MULTI_NAME_PREFIX_OP:
489
490                         /* More than one name_seg, search rules do not apply */
491
492                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
493
494                         /* Extract segment count, point to first name segment */
495
496                         path++;
497                         num_segments = (u32) (u8) * path;
498                         path++;
499
500                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
501                                           "Multi Pathname (%d Segments, Flags=%X)\n",
502                                           num_segments, flags));
503                         break;
504
505                 default:
506                         /*
507                          * Not a Null name, no Dual or Multi prefix, hence there is
508                          * only one name segment and Pathname is already pointing to it.
509                          */
510                         num_segments = 1;
511
512                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
513                                           "Simple Pathname (1 segment, Flags=%X)\n",
514                                           flags));
515                         break;
516                 }
517
518                 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
519         }
520
521         /*
522          * Search namespace for each segment of the name.  Loop through and
523          * verify (or add to the namespace) each name segment.
524          *
525          * The object type is significant only at the last name
526          * segment.  (We don't care about the types along the path, only
527          * the type of the final target object.)
528          */
529         this_search_type = ACPI_TYPE_ANY;
530         current_node = this_node;
531         while (num_segments && current_node) {
532                 num_segments--;
533                 if (!num_segments) {
534                         /*
535                          * This is the last segment, enable typechecking
536                          */
537                         this_search_type = type;
538
539                         /*
540                          * Only allow automatic parent search (search rules) if the caller
541                          * requested it AND we have a single, non-fully-qualified name_seg
542                          */
543                         if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
544                             (flags & ACPI_NS_SEARCH_PARENT)) {
545                                 local_flags |= ACPI_NS_SEARCH_PARENT;
546                         }
547
548                         /* Set error flag according to caller */
549
550                         if (flags & ACPI_NS_ERROR_IF_FOUND) {
551                                 local_flags |= ACPI_NS_ERROR_IF_FOUND;
552                         }
553                 }
554
555                 /* Extract one ACPI name from the front of the pathname */
556
557                 ACPI_MOVE_32_TO_32(&simple_name, path);
558
559                 /* Try to find the single (4 character) ACPI name */
560
561                 status =
562                     acpi_ns_search_and_enter(simple_name, walk_state,
563                                              current_node, interpreter_mode,
564                                              this_search_type, local_flags,
565                                              &this_node);
566                 if (ACPI_FAILURE(status)) {
567                         if (status == AE_NOT_FOUND) {
568                                 /* Name not found in ACPI namespace */
569
570                                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
571                                                   "Name [%4.4s] not found in scope [%4.4s] %p\n",
572                                                   (char *)&simple_name,
573                                                   (char *)&current_node->name,
574                                                   current_node));
575                         }
576
577                         *return_node = this_node;
578                         return_ACPI_STATUS(status);
579                 }
580
581                 /*
582                  * Sanity typecheck of the target object:
583                  *
584                  * If 1) This is the last segment (num_segments == 0)
585                  *    2) And we are looking for a specific type
586                  *       (Not checking for TYPE_ANY)
587                  *    3) Which is not an alias
588                  *    4) Which is not a local type (TYPE_SCOPE)
589                  *    5) And the type of target object is known (not TYPE_ANY)
590                  *    6) And target object does not match what we are looking for
591                  *
592                  * Then we have a type mismatch.  Just warn and ignore it.
593                  */
594                 if ((num_segments == 0) &&
595                     (type_to_check_for != ACPI_TYPE_ANY) &&
596                     (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
597                     (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) &&
598                     (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) &&
599                     (this_node->type != ACPI_TYPE_ANY) &&
600                     (this_node->type != type_to_check_for)) {
601                         /* Complain about a type mismatch */
602
603                         ACPI_REPORT_WARNING(("ns_lookup: Type mismatch on %4.4s (%s), searching for (%s)\n", (char *)&simple_name, acpi_ut_get_type_name(this_node->type), acpi_ut_get_type_name(type_to_check_for)));
604                 }
605
606                 /*
607                  * If this is the last name segment and we are not looking for a
608                  * specific type, but the type of found object is known, use that type
609                  * to see if it opens a scope.
610                  */
611                 if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
612                         type = this_node->type;
613                 }
614
615                 /* Point to next name segment and make this node current */
616
617                 path += ACPI_NAME_SIZE;
618                 current_node = this_node;
619         }
620
621         /*
622          * Always check if we need to open a new scope
623          */
624         if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
625                 /*
626                  * If entry is a type which opens a scope, push the new scope on the
627                  * scope stack.
628                  */
629                 if (acpi_ns_opens_scope(type)) {
630                         status =
631                             acpi_ds_scope_stack_push(this_node, type,
632                                                      walk_state);
633                         if (ACPI_FAILURE(status)) {
634                                 return_ACPI_STATUS(status);
635                         }
636                 }
637         }
638
639         *return_node = this_node;
640         return_ACPI_STATUS(AE_OK);
641 }