Merge branch 'linus' into core/iommu
[linux-2.6] / 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 - 2008, 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.
122                  * If entry in pre_defined_names[] specifies an
123                  * initial value, create the initial value.
124                  */
125                 if (init_val->val) {
126                         status = acpi_os_predefined_override(init_val, &val);
127                         if (ACPI_FAILURE(status)) {
128                                 ACPI_ERROR((AE_INFO,
129                                             "Could not override predefined %s",
130                                             init_val->name));
131                         }
132
133                         if (!val) {
134                                 val = init_val->val;
135                         }
136
137                         /*
138                          * Entry requests an initial value, allocate a
139                          * descriptor for it.
140                          */
141                         obj_desc =
142                             acpi_ut_create_internal_object(init_val->type);
143                         if (!obj_desc) {
144                                 status = AE_NO_MEMORY;
145                                 goto unlock_and_exit;
146                         }
147
148                         /*
149                          * Convert value string from table entry to
150                          * internal representation. Only types actually
151                          * used for initial values are implemented here.
152                          */
153                         switch (init_val->type) {
154                         case ACPI_TYPE_METHOD:
155                                 obj_desc->method.param_count =
156                                     (u8) ACPI_TO_INTEGER(val);
157                                 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
158
159 #if defined (ACPI_ASL_COMPILER)
160
161                                 /* Save the parameter count for the i_aSL compiler */
162
163                                 new_node->value = obj_desc->method.param_count;
164 #else
165                                 /* Mark this as a very SPECIAL method */
166
167                                 obj_desc->method.method_flags =
168                                     AML_METHOD_INTERNAL_ONLY;
169                                 obj_desc->method.implementation =
170                                     acpi_ut_osi_implementation;
171 #endif
172                                 break;
173
174                         case ACPI_TYPE_INTEGER:
175
176                                 obj_desc->integer.value = ACPI_TO_INTEGER(val);
177                                 break;
178
179                         case ACPI_TYPE_STRING:
180
181                                 /*
182                                  * Build an object around the static string
183                                  */
184                                 obj_desc->string.length =
185                                     (u32) ACPI_STRLEN(val);
186                                 obj_desc->string.pointer = val;
187                                 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
188                                 break;
189
190                         case ACPI_TYPE_MUTEX:
191
192                                 obj_desc->mutex.node = new_node;
193                                 obj_desc->mutex.sync_level =
194                                     (u8) (ACPI_TO_INTEGER(val) - 1);
195
196                                 /* Create a mutex */
197
198                                 status =
199                                     acpi_os_create_mutex(&obj_desc->mutex.
200                                                          os_mutex);
201                                 if (ACPI_FAILURE(status)) {
202                                         acpi_ut_remove_reference(obj_desc);
203                                         goto unlock_and_exit;
204                                 }
205
206                                 /* Special case for ACPI Global Lock */
207
208                                 if (ACPI_STRCMP(init_val->name, "_GL_") == 0) {
209                                         acpi_gbl_global_lock_mutex = obj_desc;
210
211                                         /* Create additional counting semaphore for global lock */
212
213                                         status =
214                                             acpi_os_create_semaphore(1, 0,
215                                                                      &acpi_gbl_global_lock_semaphore);
216                                         if (ACPI_FAILURE(status)) {
217                                                 acpi_ut_remove_reference
218                                                     (obj_desc);
219                                                 goto unlock_and_exit;
220                                         }
221                                 }
222                                 break;
223
224                         default:
225
226                                 ACPI_ERROR((AE_INFO,
227                                             "Unsupported initial type value %X",
228                                             init_val->type));
229                                 acpi_ut_remove_reference(obj_desc);
230                                 obj_desc = NULL;
231                                 continue;
232                         }
233
234                         /* Store pointer to value descriptor in the Node */
235
236                         status = acpi_ns_attach_object(new_node, obj_desc,
237                                                        ACPI_GET_OBJECT_TYPE
238                                                        (obj_desc));
239
240                         /* Remove local reference to the object */
241
242                         acpi_ut_remove_reference(obj_desc);
243                 }
244         }
245
246       unlock_and_exit:
247         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
248
249         /* Save a handle to "_GPE", it is always present */
250
251         if (ACPI_SUCCESS(status)) {
252                 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
253                                           &acpi_gbl_fadt_gpe_device);
254         }
255
256         return_ACPI_STATUS(status);
257 }
258
259 /*******************************************************************************
260  *
261  * FUNCTION:    acpi_ns_lookup
262  *
263  * PARAMETERS:  scope_info      - Current scope info block
264  *              Pathname        - Search pathname, in internal format
265  *                                (as represented in the AML stream)
266  *              Type            - Type associated with name
267  *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
268  *              Flags           - Flags describing the search restrictions
269  *              walk_state      - Current state of the walk
270  *              return_node     - Where the Node is placed (if found
271  *                                or created successfully)
272  *
273  * RETURN:      Status
274  *
275  * DESCRIPTION: Find or enter the passed name in the name space.
276  *              Log an error if name not found in Exec mode.
277  *
278  * MUTEX:       Assumes namespace is locked.
279  *
280  ******************************************************************************/
281
282 acpi_status
283 acpi_ns_lookup(union acpi_generic_state *scope_info,
284                char *pathname,
285                acpi_object_type type,
286                acpi_interpreter_mode interpreter_mode,
287                u32 flags,
288                struct acpi_walk_state *walk_state,
289                struct acpi_namespace_node **return_node)
290 {
291         acpi_status status;
292         char *path = pathname;
293         struct acpi_namespace_node *prefix_node;
294         struct acpi_namespace_node *current_node = NULL;
295         struct acpi_namespace_node *this_node = NULL;
296         u32 num_segments;
297         u32 num_carats;
298         acpi_name simple_name;
299         acpi_object_type type_to_check_for;
300         acpi_object_type this_search_type;
301         u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
302         u32 local_flags;
303
304         ACPI_FUNCTION_TRACE(ns_lookup);
305
306         if (!return_node) {
307                 return_ACPI_STATUS(AE_BAD_PARAMETER);
308         }
309
310         local_flags = flags & ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_SEARCH_PARENT);
311         *return_node = ACPI_ENTRY_NOT_FOUND;
312         acpi_gbl_ns_lookup_count++;
313
314         if (!acpi_gbl_root_node) {
315                 return_ACPI_STATUS(AE_NO_NAMESPACE);
316         }
317
318         /*
319          * Get the prefix scope.
320          * A null scope means use the root scope
321          */
322         if ((!scope_info) || (!scope_info->scope.node)) {
323                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
324                                   "Null scope prefix, using root node (%p)\n",
325                                   acpi_gbl_root_node));
326
327                 prefix_node = acpi_gbl_root_node;
328         } else {
329                 prefix_node = scope_info->scope.node;
330                 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
331                     ACPI_DESC_TYPE_NAMED) {
332                         ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
333                                     prefix_node,
334                                     acpi_ut_get_descriptor_name(prefix_node)));
335                         return_ACPI_STATUS(AE_AML_INTERNAL);
336                 }
337
338                 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
339                         /*
340                          * This node might not be a actual "scope" node (such as a
341                          * Device/Method, etc.)  It could be a Package or other object node.
342                          * Backup up the tree to find the containing scope node.
343                          */
344                         while (!acpi_ns_opens_scope(prefix_node->type) &&
345                                prefix_node->type != ACPI_TYPE_ANY) {
346                                 prefix_node =
347                                     acpi_ns_get_parent_node(prefix_node);
348                         }
349                 }
350         }
351
352         /* Save type   TBD: may be no longer necessary */
353
354         type_to_check_for = type;
355
356         /*
357          * Begin examination of the actual pathname
358          */
359         if (!pathname) {
360
361                 /* A Null name_path is allowed and refers to the root */
362
363                 num_segments = 0;
364                 this_node = acpi_gbl_root_node;
365                 path = "";
366
367                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
368                                   "Null Pathname (Zero segments), Flags=%X\n",
369                                   flags));
370         } else {
371                 /*
372                  * Name pointer is valid (and must be in internal name format)
373                  *
374                  * Check for scope prefixes:
375                  *
376                  * As represented in the AML stream, a namepath consists of an
377                  * optional scope prefix followed by a name segment part.
378                  *
379                  * If present, the scope prefix is either a Root Prefix (in
380                  * which case the name is fully qualified), or one or more
381                  * Parent Prefixes (in which case the name's scope is relative
382                  * to the current scope).
383                  */
384                 if (*path == (u8) AML_ROOT_PREFIX) {
385
386                         /* Pathname is fully qualified, start from the root */
387
388                         this_node = acpi_gbl_root_node;
389                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
390
391                         /* Point to name segment part */
392
393                         path++;
394
395                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
396                                           "Path is absolute from root [%p]\n",
397                                           this_node));
398                 } else {
399                         /* Pathname is relative to current scope, start there */
400
401                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
402                                           "Searching relative to prefix scope [%4.4s] (%p)\n",
403                                           acpi_ut_get_node_name(prefix_node),
404                                           prefix_node));
405
406                         /*
407                          * Handle multiple Parent Prefixes (carat) by just getting
408                          * the parent node for each prefix instance.
409                          */
410                         this_node = prefix_node;
411                         num_carats = 0;
412                         while (*path == (u8) AML_PARENT_PREFIX) {
413
414                                 /* Name is fully qualified, no search rules apply */
415
416                                 search_parent_flag = ACPI_NS_NO_UPSEARCH;
417                                 /*
418                                  * Point past this prefix to the name segment
419                                  * part or the next Parent Prefix
420                                  */
421                                 path++;
422
423                                 /* Backup to the parent node */
424
425                                 num_carats++;
426                                 this_node = acpi_ns_get_parent_node(this_node);
427                                 if (!this_node) {
428
429                                         /* Current scope has no parent scope */
430
431                                         ACPI_ERROR((AE_INFO,
432                                                     "ACPI path has too many parent prefixes (^) - reached beyond root node"));
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
569                                 /* Name not found in ACPI namespace */
570
571                                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
572                                                   "Name [%4.4s] not found in scope [%4.4s] %p\n",
573                                                   (char *)&simple_name,
574                                                   (char *)&current_node->name,
575                                                   current_node));
576                         }
577
578                         *return_node = this_node;
579                         return_ACPI_STATUS(status);
580                 }
581
582                 /* More segments to follow? */
583
584                 if (num_segments > 0) {
585                         /*
586                          * If we have an alias to an object that opens a scope (such as a
587                          * device or processor), we need to dereference the alias here so that
588                          * we can access any children of the original node (via the remaining
589                          * segments).
590                          */
591                         if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
592                                 if (!this_node->object) {
593                                         return_ACPI_STATUS(AE_NOT_EXIST);
594                                 }
595
596                                 if (acpi_ns_opens_scope
597                                     (((struct acpi_namespace_node *)this_node->
598                                       object)->type)) {
599                                         this_node =
600                                             (struct acpi_namespace_node *)
601                                             this_node->object;
602                                 }
603                         }
604                 }
605
606                 /* Special handling for the last segment (num_segments == 0) */
607
608                 else {
609                         /*
610                          * Sanity typecheck of the target object:
611                          *
612                          * If 1) This is the last segment (num_segments == 0)
613                          *    2) And we are looking for a specific type
614                          *       (Not checking for TYPE_ANY)
615                          *    3) Which is not an alias
616                          *    4) Which is not a local type (TYPE_SCOPE)
617                          *    5) And the type of target object is known (not TYPE_ANY)
618                          *    6) And target object does not match what we are looking for
619                          *
620                          * Then we have a type mismatch. Just warn and ignore it.
621                          */
622                         if ((type_to_check_for != ACPI_TYPE_ANY) &&
623                             (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
624                             (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
625                             && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
626                             && (this_node->type != ACPI_TYPE_ANY)
627                             && (this_node->type != type_to_check_for)) {
628
629                                 /* Complain about a type mismatch */
630
631                                 ACPI_WARNING((AE_INFO,
632                                               "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
633                                               ACPI_CAST_PTR(char, &simple_name),
634                                               acpi_ut_get_type_name(this_node->
635                                                                     type),
636                                               acpi_ut_get_type_name
637                                               (type_to_check_for)));
638                         }
639
640                         /*
641                          * If this is the last name segment and we are not looking for a
642                          * specific type, but the type of found object is known, use that type
643                          * to (later) see if it opens a scope.
644                          */
645                         if (type == ACPI_TYPE_ANY) {
646                                 type = this_node->type;
647                         }
648                 }
649
650                 /* Point to next name segment and make this node current */
651
652                 path += ACPI_NAME_SIZE;
653                 current_node = this_node;
654         }
655
656         /*
657          * Always check if we need to open a new scope
658          */
659         if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
660                 /*
661                  * If entry is a type which opens a scope, push the new scope on the
662                  * scope stack.
663                  */
664                 if (acpi_ns_opens_scope(type)) {
665                         status =
666                             acpi_ds_scope_stack_push(this_node, type,
667                                                      walk_state);
668                         if (ACPI_FAILURE(status)) {
669                                 return_ACPI_STATUS(status);
670                         }
671                 }
672         }
673
674         *return_node = this_node;
675         return_ACPI_STATUS(AE_OK);
676 }