Merge /pub/scm/linux/kernel/git/torvalds/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 - 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 (
71         void)
72 {
73         acpi_status                         status;
74         const struct acpi_predefined_names *init_val = NULL;
75         struct acpi_namespace_node          *new_node;
76         union acpi_operand_object           *obj_desc;
77         acpi_string                         val = NULL;
78
79
80         ACPI_FUNCTION_TRACE ("ns_root_initialize");
81
82
83         status = acpi_ut_acquire_mutex (ACPI_MTX_NAMESPACE);
84         if (ACPI_FAILURE (status)) {
85                 return_ACPI_STATUS (status);
86         }
87
88         /*
89          * The global root ptr is initially NULL, so a non-NULL value indicates
90          * that acpi_ns_root_initialize() has already been called; just return.
91          */
92         if (acpi_gbl_root_node) {
93                 status = AE_OK;
94                 goto unlock_and_exit;
95         }
96
97         /*
98          * Tell the rest of the subsystem that the root is initialized
99          * (This is OK because the namespace is locked)
100          */
101         acpi_gbl_root_node = &acpi_gbl_root_node_struct;
102
103         /* Enter the pre-defined names in the name table */
104
105         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
106                 "Entering predefined entries into namespace\n"));
107
108         for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
109                 /* _OSI is optional for now, will be permanent later */
110
111                 if (!ACPI_STRCMP (init_val->name, "_OSI") && !acpi_gbl_create_osi_method) {
112                         continue;
113                 }
114
115                 status = acpi_ns_lookup (NULL, init_val->name, init_val->type,
116                                   ACPI_IMODE_LOAD_PASS2, ACPI_NS_NO_UPSEARCH,
117                                   NULL, &new_node);
118
119                 if (ACPI_FAILURE (status) || (!new_node)) /* Must be on same line for code converter */ {
120                         ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
121                                 "Could not create predefined name %s, %s\n",
122                                 init_val->name, acpi_format_exception (status)));
123                 }
124
125                 /*
126                  * Name entered successfully.
127                  * If entry in pre_defined_names[] specifies an
128                  * initial value, create the initial value.
129                  */
130                 if (init_val->val) {
131                         status = acpi_os_predefined_override (init_val, &val);
132                         if (ACPI_FAILURE (status)) {
133                                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
134                                         "Could not override predefined %s\n",
135                                         init_val->name));
136                         }
137
138                         if (!val) {
139                                 val = init_val->val;
140                         }
141
142                         /*
143                          * Entry requests an initial value, allocate a
144                          * descriptor for it.
145                          */
146                         obj_desc = acpi_ut_create_internal_object (init_val->type);
147                         if (!obj_desc) {
148                                 status = AE_NO_MEMORY;
149                                 goto unlock_and_exit;
150                         }
151
152                         /*
153                          * Convert value string from table entry to
154                          * internal representation. Only types actually
155                          * used for initial values are implemented here.
156                          */
157                         switch (init_val->type) {
158                         case ACPI_TYPE_METHOD:
159                                 obj_desc->method.param_count = (u8) ACPI_TO_INTEGER (val);
160                                 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
161
162 #if defined (_ACPI_ASL_COMPILER) || defined (_ACPI_DUMP_App)
163
164                                 /*
165                                  * i_aSL Compiler cheats by putting parameter count
166                                  * in the owner_iD
167                                  */
168                                 new_node->owner_id = obj_desc->method.param_count;
169 #else
170                                 /* Mark this as a very SPECIAL method */
171
172                                 obj_desc->method.method_flags = AML_METHOD_INTERNAL_ONLY;
173                                 obj_desc->method.implementation = acpi_ut_osi_implementation;
174 #endif
175                                 break;
176
177                         case ACPI_TYPE_INTEGER:
178
179                                 obj_desc->integer.value = ACPI_TO_INTEGER (val);
180                                 break;
181
182
183                         case ACPI_TYPE_STRING:
184
185                                 /*
186                                  * Build an object around the static string
187                                  */
188                                 obj_desc->string.length = (u32) ACPI_STRLEN (val);
189                                 obj_desc->string.pointer = val;
190                                 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
191                                 break;
192
193
194                         case ACPI_TYPE_MUTEX:
195
196                                 obj_desc->mutex.node = new_node;
197                                 obj_desc->mutex.sync_level = (u8) (ACPI_TO_INTEGER (val) - 1);
198
199                                 if (ACPI_STRCMP (init_val->name, "_GL_") == 0) {
200                                         /*
201                                          * Create a counting semaphore for the
202                                          * global lock
203                                          */
204                                         status = acpi_os_create_semaphore (ACPI_NO_UNIT_LIMIT,
205                                                          1, &obj_desc->mutex.semaphore);
206                                         if (ACPI_FAILURE (status)) {
207                                                 acpi_ut_remove_reference (obj_desc);
208                                                 goto unlock_and_exit;
209                                         }
210
211                                         /*
212                                          * We just created the mutex for the
213                                          * global lock, save it
214                                          */
215                                         acpi_gbl_global_lock_semaphore = obj_desc->mutex.semaphore;
216                                 }
217                                 else {
218                                         /* Create a mutex */
219
220                                         status = acpi_os_create_semaphore (1, 1,
221                                                            &obj_desc->mutex.semaphore);
222                                         if (ACPI_FAILURE (status)) {
223                                                 acpi_ut_remove_reference (obj_desc);
224                                                 goto unlock_and_exit;
225                                         }
226                                 }
227                                 break;
228
229
230                         default:
231
232                                 ACPI_REPORT_ERROR (("Unsupported initial type value %X\n",
233                                         init_val->type));
234                                 acpi_ut_remove_reference (obj_desc);
235                                 obj_desc = NULL;
236                                 continue;
237                         }
238
239                         /* Store pointer to value descriptor in the Node */
240
241                         status = acpi_ns_attach_object (new_node, obj_desc,
242                                          ACPI_GET_OBJECT_TYPE (obj_desc));
243
244                         /* Remove local reference to the object */
245
246                         acpi_ut_remove_reference (obj_desc);
247                 }
248         }
249
250
251 unlock_and_exit:
252         (void) acpi_ut_release_mutex (ACPI_MTX_NAMESPACE);
253
254         /* Save a handle to "_GPE", it is always present */
255
256         if (ACPI_SUCCESS (status)) {
257                 status = acpi_ns_get_node_by_path ("\\_GPE", NULL, ACPI_NS_NO_UPSEARCH,
258                                   &acpi_gbl_fadt_gpe_device);
259         }
260
261         return_ACPI_STATUS (status);
262 }
263
264
265 /*******************************************************************************
266  *
267  * FUNCTION:    acpi_ns_lookup
268  *
269  * PARAMETERS:  scope_info      - Current scope info block
270  *              Pathname        - Search pathname, in internal format
271  *                                (as represented in the AML stream)
272  *              Type            - Type associated with name
273  *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
274  *              Flags           - Flags describing the search restrictions
275  *              walk_state      - Current state of the walk
276  *              return_node     - Where the Node is placed (if found
277  *                                or created successfully)
278  *
279  * RETURN:      Status
280  *
281  * DESCRIPTION: Find or enter the passed name in the name space.
282  *              Log an error if name not found in Exec mode.
283  *
284  * MUTEX:       Assumes namespace is locked.
285  *
286  ******************************************************************************/
287
288 acpi_status
289 acpi_ns_lookup (
290         union acpi_generic_state        *scope_info,
291         char                            *pathname,
292         acpi_object_type                type,
293         acpi_interpreter_mode           interpreter_mode,
294         u32                             flags,
295         struct acpi_walk_state          *walk_state,
296         struct acpi_namespace_node      **return_node)
297 {
298         acpi_status                     status;
299         char                            *path = pathname;
300         struct acpi_namespace_node      *prefix_node;
301         struct acpi_namespace_node      *current_node = NULL;
302         struct acpi_namespace_node      *this_node = NULL;
303         u32                             num_segments;
304         u32                             num_carats;
305         acpi_name                       simple_name;
306         acpi_object_type                type_to_check_for;
307         acpi_object_type                this_search_type;
308         u32                             search_parent_flag = ACPI_NS_SEARCH_PARENT;
309         u32                             local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND |
310                            ACPI_NS_SEARCH_PARENT);
311
312
313         ACPI_FUNCTION_TRACE ("ns_lookup");
314
315
316         if (!return_node) {
317                 return_ACPI_STATUS (AE_BAD_PARAMETER);
318         }
319
320         acpi_gbl_ns_lookup_count++;
321         *return_node = ACPI_ENTRY_NOT_FOUND;
322
323         if (!acpi_gbl_root_node) {
324                 return_ACPI_STATUS (AE_NO_NAMESPACE);
325         }
326
327         /*
328          * Get the prefix scope.
329          * A null scope means use the root scope
330          */
331         if ((!scope_info) ||
332                 (!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         }
339         else {
340                 prefix_node = scope_info->scope.node;
341                 if (ACPI_GET_DESCRIPTOR_TYPE (prefix_node) != ACPI_DESC_TYPE_NAMED) {
342                         ACPI_REPORT_ERROR (("ns_lookup: %p is not a namespace node [%s]\n",
343                                         prefix_node, acpi_ut_get_descriptor_name (prefix_node)));
344                         return_ACPI_STATUS (AE_AML_INTERNAL);
345                 }
346
347                 /*
348                  * This node might not be a actual "scope" node (such as a
349                  * Device/Method, etc.)  It could be a Package or other object node.
350                  * Backup up the tree to find the containing scope node.
351                  */
352                 while (!acpi_ns_opens_scope (prefix_node->type) &&
353                                 prefix_node->type != ACPI_TYPE_ANY) {
354                         prefix_node = acpi_ns_get_parent_node (prefix_node);
355                 }
356         }
357
358         /* Save type   TBD: may be no longer necessary */
359
360         type_to_check_for = type;
361
362         /*
363          * Begin examination of the actual pathname
364          */
365         if (!pathname) {
366                 /* A Null name_path is allowed and refers to the root */
367
368                 num_segments = 0;
369                 this_node    = acpi_gbl_root_node;
370                 path     = "";
371
372                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
373                         "Null Pathname (Zero segments), Flags=%X\n", flags));
374         }
375         else {
376                 /*
377                  * Name pointer is valid (and must be in internal name format)
378                  *
379                  * Check for scope prefixes:
380                  *
381                  * As represented in the AML stream, a namepath consists of an
382                  * optional scope prefix followed by a name segment part.
383                  *
384                  * If present, the scope prefix is either a Root Prefix (in
385                  * which case the name is fully qualified), or one or more
386                  * Parent Prefixes (in which case the name's scope is relative
387                  * to the current scope).
388                  */
389                 if (*path == (u8) AML_ROOT_PREFIX) {
390                         /* Pathname is fully qualified, start from the root */
391
392                         this_node = acpi_gbl_root_node;
393                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
394
395                         /* Point to name segment part */
396
397                         path++;
398
399                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
400                                 "Path is absolute from root [%p]\n", this_node));
401                 }
402                 else {
403                         /* Pathname is relative to current scope, start there */
404
405                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
406                                 "Searching relative to prefix scope [%4.4s] (%p)\n",
407                                 acpi_ut_get_node_name (prefix_node), 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 (
433                                                 ("ACPI path has too many parent prefixes (^) - reached beyond root node\n"));
434                                         return_ACPI_STATUS (AE_NOT_FOUND);
435                                 }
436                         }
437
438                         if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
439                                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
440                                         "Search scope is [%4.4s], path has %d carat(s)\n",
441                                         acpi_ut_get_node_name (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", flags));
485                         break;
486
487                 case AML_MULTI_NAME_PREFIX_OP:
488
489                         /* More than one name_seg, search rules do not apply */
490
491                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
492
493                         /* Extract segment count, point to first name segment */
494
495                         path++;
496                         num_segments = (u32) (u8) *path;
497                         path++;
498
499                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
500                                 "Multi Pathname (%d Segments, Flags=%X) \n",
501                                 num_segments, flags));
502                         break;
503
504                 default:
505                         /*
506                          * Not a Null name, no Dual or Multi prefix, hence there is
507                          * only one name segment and Pathname is already pointing to it.
508                          */
509                         num_segments = 1;
510
511                         ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
512                                 "Simple Pathname (1 segment, Flags=%X)\n", flags));
513                         break;
514                 }
515
516                 ACPI_DEBUG_EXEC (acpi_ns_print_pathname (num_segments, path));
517         }
518
519
520         /*
521          * Search namespace for each segment of the name.  Loop through and
522          * verify (or add to the namespace) each name segment.
523          *
524          * The object type is significant only at the last name
525          * segment.  (We don't care about the types along the path, only
526          * the type of the final target object.)
527          */
528         this_search_type = ACPI_TYPE_ANY;
529         current_node = this_node;
530         while (num_segments && current_node) {
531                 num_segments--;
532                 if (!num_segments) {
533                         /*
534                          * This is the last segment, enable typechecking
535                          */
536                         this_search_type = type;
537
538                         /*
539                          * Only allow automatic parent search (search rules) if the caller
540                          * requested it AND we have a single, non-fully-qualified name_seg
541                          */
542                         if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
543                                 (flags & ACPI_NS_SEARCH_PARENT)) {
544                                 local_flags |= ACPI_NS_SEARCH_PARENT;
545                         }
546
547                         /* Set error flag according to caller */
548
549                         if (flags & ACPI_NS_ERROR_IF_FOUND) {
550                                 local_flags |= ACPI_NS_ERROR_IF_FOUND;
551                         }
552                 }
553
554                 /* Extract one ACPI name from the front of the pathname */
555
556                 ACPI_MOVE_32_TO_32 (&simple_name, path);
557
558                 /* Try to find the single (4 character) ACPI name */
559
560                 status = acpi_ns_search_and_enter (simple_name, walk_state, current_node,
561                                  interpreter_mode, this_search_type, local_flags, &this_node);
562                 if (ACPI_FAILURE (status)) {
563                         if (status == AE_NOT_FOUND) {
564                                 /* Name not found in ACPI namespace */
565
566                                 ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
567                                         "Name [%4.4s] not found in scope [%4.4s] %p\n",
568                                         (char *) &simple_name, (char *) &current_node->name,
569                                         current_node));
570                         }
571
572                         *return_node = this_node;
573                         return_ACPI_STATUS (status);
574                 }
575
576                 /*
577                  * Sanity typecheck of the target object:
578                  *
579                  * If 1) This is the last segment (num_segments == 0)
580                  *    2) And we are looking for a specific type
581                  *       (Not checking for TYPE_ANY)
582                  *    3) Which is not an alias
583                  *    4) Which is not a local type (TYPE_SCOPE)
584                  *    5) And the type of target object is known (not TYPE_ANY)
585                  *    6) And target object does not match what we are looking for
586                  *
587                  * Then we have a type mismatch.  Just warn and ignore it.
588                  */
589                 if ((num_segments       == 0)                               &&
590                         (type_to_check_for  != ACPI_TYPE_ANY)                   &&
591                         (type_to_check_for  != ACPI_TYPE_LOCAL_ALIAS)           &&
592                         (type_to_check_for  != ACPI_TYPE_LOCAL_METHOD_ALIAS)    &&
593                         (type_to_check_for  != ACPI_TYPE_LOCAL_SCOPE)           &&
594                         (this_node->type    != ACPI_TYPE_ANY)                   &&
595                         (this_node->type    != type_to_check_for)) {
596                         /* Complain about a type mismatch */
597
598                         ACPI_REPORT_WARNING (
599                                 ("ns_lookup: Type mismatch on %4.4s (%s), searching for (%s)\n",
600                                 (char *) &simple_name, acpi_ut_get_type_name (this_node->type),
601                                 acpi_ut_get_type_name (type_to_check_for)));
602                 }
603
604                 /*
605                  * If this is the last name segment and we are not looking for a
606                  * specific type, but the type of found object is known, use that type
607                  * to see if it opens a scope.
608                  */
609                 if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
610                         type = this_node->type;
611                 }
612
613                 /* Point to next name segment and make this node current */
614
615                 path += ACPI_NAME_SIZE;
616                 current_node = this_node;
617         }
618
619         /*
620          * Always check if we need to open a new scope
621          */
622         if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
623                 /*
624                  * If entry is a type which opens a scope, push the new scope on the
625                  * scope stack.
626                  */
627                 if (acpi_ns_opens_scope (type)) {
628                         status = acpi_ds_scope_stack_push (this_node, type, walk_state);
629                         if (ACPI_FAILURE (status)) {
630                                 return_ACPI_STATUS (status);
631                         }
632                 }
633         }
634
635         *return_node = this_node;
636         return_ACPI_STATUS (AE_OK);
637 }
638