Merge tag 'for-linus-4.19b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel...
[sfrench/cifs-2.6.git] / drivers / acpi / acpica / nsaccess.c
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /*******************************************************************************
3  *
4  * Module Name: nsaccess - Top-level functions for accessing ACPI namespace
5  *
6  ******************************************************************************/
7
8 #include <acpi/acpi.h>
9 #include "accommon.h"
10 #include "amlcode.h"
11 #include "acnamesp.h"
12 #include "acdispat.h"
13
14 #ifdef ACPI_ASL_COMPILER
15 #include "acdisasm.h"
16 #endif
17
18 #define _COMPONENT          ACPI_NAMESPACE
19 ACPI_MODULE_NAME("nsaccess")
20
21 /*******************************************************************************
22  *
23  * FUNCTION:    acpi_ns_root_initialize
24  *
25  * PARAMETERS:  None
26  *
27  * RETURN:      Status
28  *
29  * DESCRIPTION: Allocate and initialize the default root named objects
30  *
31  * MUTEX:       Locks namespace for entire execution
32  *
33  ******************************************************************************/
34 acpi_status acpi_ns_root_initialize(void)
35 {
36         acpi_status status;
37         const struct acpi_predefined_names *init_val = NULL;
38         struct acpi_namespace_node *new_node;
39         union acpi_operand_object *obj_desc;
40         acpi_string val = NULL;
41
42         ACPI_FUNCTION_TRACE(ns_root_initialize);
43
44         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
45         if (ACPI_FAILURE(status)) {
46                 return_ACPI_STATUS(status);
47         }
48
49         /*
50          * The global root ptr is initially NULL, so a non-NULL value indicates
51          * that acpi_ns_root_initialize() has already been called; just return.
52          */
53         if (acpi_gbl_root_node) {
54                 status = AE_OK;
55                 goto unlock_and_exit;
56         }
57
58         /*
59          * Tell the rest of the subsystem that the root is initialized
60          * (This is OK because the namespace is locked)
61          */
62         acpi_gbl_root_node = &acpi_gbl_root_node_struct;
63
64         /* Enter the pre-defined names in the name table */
65
66         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
67                           "Entering predefined entries into namespace\n"));
68
69         for (init_val = acpi_gbl_pre_defined_names; init_val->name; init_val++) {
70
71                 /* _OSI is optional for now, will be permanent later */
72
73                 if (!strcmp(init_val->name, "_OSI")
74                     && !acpi_gbl_create_osi_method) {
75                         continue;
76                 }
77
78                 status =
79                     acpi_ns_lookup(NULL, ACPI_CAST_PTR(char, init_val->name),
80                                    init_val->type, ACPI_IMODE_LOAD_PASS2,
81                                    ACPI_NS_NO_UPSEARCH, NULL, &new_node);
82                 if (ACPI_FAILURE(status)) {
83                         ACPI_EXCEPTION((AE_INFO, status,
84                                         "Could not create predefined name %s",
85                                         init_val->name));
86                         continue;
87                 }
88
89                 /*
90                  * Name entered successfully. If entry in pre_defined_names[] specifies
91                  * an initial value, create the initial value.
92                  */
93                 if (init_val->val) {
94                         status = acpi_os_predefined_override(init_val, &val);
95                         if (ACPI_FAILURE(status)) {
96                                 ACPI_ERROR((AE_INFO,
97                                             "Could not override predefined %s",
98                                             init_val->name));
99                         }
100
101                         if (!val) {
102                                 val = init_val->val;
103                         }
104
105                         /*
106                          * Entry requests an initial value, allocate a
107                          * descriptor for it.
108                          */
109                         obj_desc =
110                             acpi_ut_create_internal_object(init_val->type);
111                         if (!obj_desc) {
112                                 status = AE_NO_MEMORY;
113                                 goto unlock_and_exit;
114                         }
115
116                         /*
117                          * Convert value string from table entry to
118                          * internal representation. Only types actually
119                          * used for initial values are implemented here.
120                          */
121                         switch (init_val->type) {
122                         case ACPI_TYPE_METHOD:
123
124                                 obj_desc->method.param_count =
125                                     (u8) ACPI_TO_INTEGER(val);
126                                 obj_desc->common.flags |= AOPOBJ_DATA_VALID;
127
128 #if defined (ACPI_ASL_COMPILER)
129
130                                 /* Save the parameter count for the iASL compiler */
131
132                                 new_node->value = obj_desc->method.param_count;
133 #else
134                                 /* Mark this as a very SPECIAL method */
135
136                                 obj_desc->method.info_flags =
137                                     ACPI_METHOD_INTERNAL_ONLY;
138                                 obj_desc->method.dispatch.implementation =
139                                     acpi_ut_osi_implementation;
140 #endif
141                                 break;
142
143                         case ACPI_TYPE_INTEGER:
144
145                                 obj_desc->integer.value = ACPI_TO_INTEGER(val);
146                                 break;
147
148                         case ACPI_TYPE_STRING:
149
150                                 /* Build an object around the static string */
151
152                                 obj_desc->string.length = (u32)strlen(val);
153                                 obj_desc->string.pointer = val;
154                                 obj_desc->common.flags |= AOPOBJ_STATIC_POINTER;
155                                 break;
156
157                         case ACPI_TYPE_MUTEX:
158
159                                 obj_desc->mutex.node = new_node;
160                                 obj_desc->mutex.sync_level =
161                                     (u8) (ACPI_TO_INTEGER(val) - 1);
162
163                                 /* Create a mutex */
164
165                                 status =
166                                     acpi_os_create_mutex(&obj_desc->mutex.
167                                                          os_mutex);
168                                 if (ACPI_FAILURE(status)) {
169                                         acpi_ut_remove_reference(obj_desc);
170                                         goto unlock_and_exit;
171                                 }
172
173                                 /* Special case for ACPI Global Lock */
174
175                                 if (strcmp(init_val->name, "_GL_") == 0) {
176                                         acpi_gbl_global_lock_mutex = obj_desc;
177
178                                         /* Create additional counting semaphore for global lock */
179
180                                         status =
181                                             acpi_os_create_semaphore(1, 0,
182                                                                      &acpi_gbl_global_lock_semaphore);
183                                         if (ACPI_FAILURE(status)) {
184                                                 acpi_ut_remove_reference
185                                                     (obj_desc);
186                                                 goto unlock_and_exit;
187                                         }
188                                 }
189                                 break;
190
191                         default:
192
193                                 ACPI_ERROR((AE_INFO,
194                                             "Unsupported initial type value 0x%X",
195                                             init_val->type));
196                                 acpi_ut_remove_reference(obj_desc);
197                                 obj_desc = NULL;
198                                 continue;
199                         }
200
201                         /* Store pointer to value descriptor in the Node */
202
203                         status = acpi_ns_attach_object(new_node, obj_desc,
204                                                        obj_desc->common.type);
205
206                         /* Remove local reference to the object */
207
208                         acpi_ut_remove_reference(obj_desc);
209                 }
210         }
211
212 unlock_and_exit:
213         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
214
215         /* Save a handle to "_GPE", it is always present */
216
217         if (ACPI_SUCCESS(status)) {
218                 status = acpi_ns_get_node(NULL, "\\_GPE", ACPI_NS_NO_UPSEARCH,
219                                           &acpi_gbl_fadt_gpe_device);
220         }
221
222         return_ACPI_STATUS(status);
223 }
224
225 /*******************************************************************************
226  *
227  * FUNCTION:    acpi_ns_lookup
228  *
229  * PARAMETERS:  scope_info      - Current scope info block
230  *              pathname        - Search pathname, in internal format
231  *                                (as represented in the AML stream)
232  *              type            - Type associated with name
233  *              interpreter_mode - IMODE_LOAD_PASS2 => add name if not found
234  *              flags           - Flags describing the search restrictions
235  *              walk_state      - Current state of the walk
236  *              return_node     - Where the Node is placed (if found
237  *                                or created successfully)
238  *
239  * RETURN:      Status
240  *
241  * DESCRIPTION: Find or enter the passed name in the name space.
242  *              Log an error if name not found in Exec mode.
243  *
244  * MUTEX:       Assumes namespace is locked.
245  *
246  ******************************************************************************/
247
248 acpi_status
249 acpi_ns_lookup(union acpi_generic_state *scope_info,
250                char *pathname,
251                acpi_object_type type,
252                acpi_interpreter_mode interpreter_mode,
253                u32 flags,
254                struct acpi_walk_state *walk_state,
255                struct acpi_namespace_node **return_node)
256 {
257         acpi_status status;
258         char *path = pathname;
259         char *external_path;
260         struct acpi_namespace_node *prefix_node;
261         struct acpi_namespace_node *current_node = NULL;
262         struct acpi_namespace_node *this_node = NULL;
263         u32 num_segments;
264         u32 num_carats;
265         acpi_name simple_name;
266         acpi_object_type type_to_check_for;
267         acpi_object_type this_search_type;
268         u32 search_parent_flag = ACPI_NS_SEARCH_PARENT;
269         u32 local_flags;
270
271         ACPI_FUNCTION_TRACE(ns_lookup);
272
273         if (!return_node) {
274                 return_ACPI_STATUS(AE_BAD_PARAMETER);
275         }
276
277         local_flags = flags &
278             ~(ACPI_NS_ERROR_IF_FOUND | ACPI_NS_OVERRIDE_IF_FOUND |
279               ACPI_NS_SEARCH_PARENT);
280         *return_node = ACPI_ENTRY_NOT_FOUND;
281         acpi_gbl_ns_lookup_count++;
282
283         if (!acpi_gbl_root_node) {
284                 return_ACPI_STATUS(AE_NO_NAMESPACE);
285         }
286
287         /* Get the prefix scope. A null scope means use the root scope */
288
289         if ((!scope_info) || (!scope_info->scope.node)) {
290                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
291                                   "Null scope prefix, using root node (%p)\n",
292                                   acpi_gbl_root_node));
293
294                 prefix_node = acpi_gbl_root_node;
295         } else {
296                 prefix_node = scope_info->scope.node;
297                 if (ACPI_GET_DESCRIPTOR_TYPE(prefix_node) !=
298                     ACPI_DESC_TYPE_NAMED) {
299                         ACPI_ERROR((AE_INFO, "%p is not a namespace node [%s]",
300                                     prefix_node,
301                                     acpi_ut_get_descriptor_name(prefix_node)));
302                         return_ACPI_STATUS(AE_AML_INTERNAL);
303                 }
304
305                 if (!(flags & ACPI_NS_PREFIX_IS_SCOPE)) {
306                         /*
307                          * This node might not be a actual "scope" node (such as a
308                          * Device/Method, etc.)  It could be a Package or other object
309                          * node. Backup up the tree to find the containing scope node.
310                          */
311                         while (!acpi_ns_opens_scope(prefix_node->type) &&
312                                prefix_node->type != ACPI_TYPE_ANY) {
313                                 prefix_node = prefix_node->parent;
314                         }
315                 }
316         }
317
318         /* Save type. TBD: may be no longer necessary */
319
320         type_to_check_for = type;
321
322         /*
323          * Begin examination of the actual pathname
324          */
325         if (!pathname) {
326
327                 /* A Null name_path is allowed and refers to the root */
328
329                 num_segments = 0;
330                 this_node = acpi_gbl_root_node;
331                 path = "";
332
333                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
334                                   "Null Pathname (Zero segments), Flags=%X\n",
335                                   flags));
336         } else {
337                 /*
338                  * Name pointer is valid (and must be in internal name format)
339                  *
340                  * Check for scope prefixes:
341                  *
342                  * As represented in the AML stream, a namepath consists of an
343                  * optional scope prefix followed by a name segment part.
344                  *
345                  * If present, the scope prefix is either a Root Prefix (in
346                  * which case the name is fully qualified), or one or more
347                  * Parent Prefixes (in which case the name's scope is relative
348                  * to the current scope).
349                  */
350                 if (*path == (u8) AML_ROOT_PREFIX) {
351
352                         /* Pathname is fully qualified, start from the root */
353
354                         this_node = acpi_gbl_root_node;
355                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
356
357                         /* Point to name segment part */
358
359                         path++;
360
361                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
362                                           "Path is absolute from root [%p]\n",
363                                           this_node));
364                 } else {
365                         /* Pathname is relative to current scope, start there */
366
367                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
368                                           "Searching relative to prefix scope [%4.4s] (%p)\n",
369                                           acpi_ut_get_node_name(prefix_node),
370                                           prefix_node));
371
372                         /*
373                          * Handle multiple Parent Prefixes (carat) by just getting
374                          * the parent node for each prefix instance.
375                          */
376                         this_node = prefix_node;
377                         num_carats = 0;
378                         while (*path == (u8) AML_PARENT_PREFIX) {
379
380                                 /* Name is fully qualified, no search rules apply */
381
382                                 search_parent_flag = ACPI_NS_NO_UPSEARCH;
383
384                                 /*
385                                  * Point past this prefix to the name segment
386                                  * part or the next Parent Prefix
387                                  */
388                                 path++;
389
390                                 /* Backup to the parent node */
391
392                                 num_carats++;
393                                 this_node = this_node->parent;
394                                 if (!this_node) {
395                                         /*
396                                          * Current scope has no parent scope. Externalize
397                                          * the internal path for error message.
398                                          */
399                                         status =
400                                             acpi_ns_externalize_name
401                                             (ACPI_UINT32_MAX, pathname, NULL,
402                                              &external_path);
403                                         if (ACPI_SUCCESS(status)) {
404                                                 ACPI_ERROR((AE_INFO,
405                                                             "%s: Path has too many parent prefixes (^)",
406                                                             external_path));
407
408                                                 ACPI_FREE(external_path);
409                                         }
410
411                                         return_ACPI_STATUS(AE_NOT_FOUND);
412                                 }
413                         }
414
415                         if (search_parent_flag == ACPI_NS_NO_UPSEARCH) {
416                                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
417                                                   "Search scope is [%4.4s], path has %u carat(s)\n",
418                                                   acpi_ut_get_node_name
419                                                   (this_node), num_carats));
420                         }
421                 }
422
423                 /*
424                  * Determine the number of ACPI name segments in this pathname.
425                  *
426                  * The segment part consists of either:
427                  *  - A Null name segment (0)
428                  *  - A dual_name_prefix followed by two 4-byte name segments
429                  *  - A multi_name_prefix followed by a byte indicating the
430                  *      number of segments and the segments themselves.
431                  *  - A single 4-byte name segment
432                  *
433                  * Examine the name prefix opcode, if any, to determine the number of
434                  * segments.
435                  */
436                 switch (*path) {
437                 case 0:
438                         /*
439                          * Null name after a root or parent prefixes. We already
440                          * have the correct target node and there are no name segments.
441                          */
442                         num_segments = 0;
443                         type = this_node->type;
444
445                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
446                                           "Prefix-only Pathname (Zero name segments), Flags=%X\n",
447                                           flags));
448                         break;
449
450                 case AML_DUAL_NAME_PREFIX:
451
452                         /* More than one name_seg, search rules do not apply */
453
454                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
455
456                         /* Two segments, point to first name segment */
457
458                         num_segments = 2;
459                         path++;
460
461                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
462                                           "Dual Pathname (2 segments, Flags=%X)\n",
463                                           flags));
464                         break;
465
466                 case AML_MULTI_NAME_PREFIX:
467
468                         /* More than one name_seg, search rules do not apply */
469
470                         search_parent_flag = ACPI_NS_NO_UPSEARCH;
471
472                         /* Extract segment count, point to first name segment */
473
474                         path++;
475                         num_segments = (u32) (u8) * path;
476                         path++;
477
478                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
479                                           "Multi Pathname (%u Segments, Flags=%X)\n",
480                                           num_segments, flags));
481                         break;
482
483                 default:
484                         /*
485                          * Not a Null name, no Dual or Multi prefix, hence there is
486                          * only one name segment and Pathname is already pointing to it.
487                          */
488                         num_segments = 1;
489
490                         ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
491                                           "Simple Pathname (1 segment, Flags=%X)\n",
492                                           flags));
493                         break;
494                 }
495
496                 ACPI_DEBUG_EXEC(acpi_ns_print_pathname(num_segments, path));
497         }
498
499         /*
500          * Search namespace for each segment of the name. Loop through and
501          * verify (or add to the namespace) each name segment.
502          *
503          * The object type is significant only at the last name
504          * segment. (We don't care about the types along the path, only
505          * the type of the final target object.)
506          */
507         this_search_type = ACPI_TYPE_ANY;
508         current_node = this_node;
509         while (num_segments && current_node) {
510                 num_segments--;
511                 if (!num_segments) {
512
513                         /* This is the last segment, enable typechecking */
514
515                         this_search_type = type;
516
517                         /*
518                          * Only allow automatic parent search (search rules) if the caller
519                          * requested it AND we have a single, non-fully-qualified name_seg
520                          */
521                         if ((search_parent_flag != ACPI_NS_NO_UPSEARCH) &&
522                             (flags & ACPI_NS_SEARCH_PARENT)) {
523                                 local_flags |= ACPI_NS_SEARCH_PARENT;
524                         }
525
526                         /* Set error flag according to caller */
527
528                         if (flags & ACPI_NS_ERROR_IF_FOUND) {
529                                 local_flags |= ACPI_NS_ERROR_IF_FOUND;
530                         }
531
532                         /* Set override flag according to caller */
533
534                         if (flags & ACPI_NS_OVERRIDE_IF_FOUND) {
535                                 local_flags |= ACPI_NS_OVERRIDE_IF_FOUND;
536                         }
537                 }
538
539                 /* Extract one ACPI name from the front of the pathname */
540
541                 ACPI_MOVE_32_TO_32(&simple_name, path);
542
543                 /* Try to find the single (4 character) ACPI name */
544
545                 status =
546                     acpi_ns_search_and_enter(simple_name, walk_state,
547                                              current_node, interpreter_mode,
548                                              this_search_type, local_flags,
549                                              &this_node);
550                 if (ACPI_FAILURE(status)) {
551                         if (status == AE_NOT_FOUND) {
552
553                                 /* Name not found in ACPI namespace */
554
555                                 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
556                                                   "Name [%4.4s] not found in scope [%4.4s] %p\n",
557                                                   (char *)&simple_name,
558                                                   (char *)&current_node->name,
559                                                   current_node));
560                         }
561 #ifdef ACPI_EXEC_APP
562                         if ((status == AE_ALREADY_EXISTS) &&
563                             (this_node->flags & ANOBJ_NODE_EARLY_INIT)) {
564                                 this_node->flags &= ~ANOBJ_NODE_EARLY_INIT;
565                                 status = AE_OK;
566                         }
567 #endif
568
569 #ifdef ACPI_ASL_COMPILER
570                         /*
571                          * If this ACPI name already exists within the namespace as an
572                          * external declaration, then mark the external as a conflicting
573                          * declaration and proceed to process the current node as if it did
574                          * not exist in the namespace. If this node is not processed as
575                          * normal, then it could cause improper namespace resolution
576                          * by failing to open a new scope.
577                          */
578                         if (acpi_gbl_disasm_flag &&
579                             (status == AE_ALREADY_EXISTS) &&
580                             ((this_node->flags & ANOBJ_IS_EXTERNAL) ||
581                              (walk_state
582                               && walk_state->opcode == AML_EXTERNAL_OP))) {
583                                 this_node->flags &= ~ANOBJ_IS_EXTERNAL;
584                                 this_node->type = (u8)this_search_type;
585                                 if (walk_state->opcode != AML_EXTERNAL_OP) {
586                                         acpi_dm_mark_external_conflict
587                                             (this_node);
588                                 }
589                                 break;
590                         }
591 #endif
592
593                         *return_node = this_node;
594                         return_ACPI_STATUS(status);
595                 }
596
597                 /* More segments to follow? */
598
599                 if (num_segments > 0) {
600                         /*
601                          * If we have an alias to an object that opens a scope (such as a
602                          * device or processor), we need to dereference the alias here so
603                          * that we can access any children of the original node (via the
604                          * remaining segments).
605                          */
606                         if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
607                                 if (!this_node->object) {
608                                         return_ACPI_STATUS(AE_NOT_EXIST);
609                                 }
610
611                                 if (acpi_ns_opens_scope
612                                     (((struct acpi_namespace_node *)
613                                       this_node->object)->type)) {
614                                         this_node =
615                                             (struct acpi_namespace_node *)
616                                             this_node->object;
617                                 }
618                         }
619                 }
620
621                 /* Special handling for the last segment (num_segments == 0) */
622
623                 else {
624                         /*
625                          * Sanity typecheck of the target object:
626                          *
627                          * If 1) This is the last segment (num_segments == 0)
628                          *    2) And we are looking for a specific type
629                          *       (Not checking for TYPE_ANY)
630                          *    3) Which is not an alias
631                          *    4) Which is not a local type (TYPE_SCOPE)
632                          *    5) And the type of target object is known (not TYPE_ANY)
633                          *    6) And target object does not match what we are looking for
634                          *
635                          * Then we have a type mismatch. Just warn and ignore it.
636                          */
637                         if ((type_to_check_for != ACPI_TYPE_ANY) &&
638                             (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
639                             (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
640                             && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
641                             && (this_node->type != ACPI_TYPE_ANY)
642                             && (this_node->type != type_to_check_for)) {
643
644                                 /* Complain about a type mismatch */
645
646                                 ACPI_WARNING((AE_INFO,
647                                               "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
648                                               ACPI_CAST_PTR(char, &simple_name),
649                                               acpi_ut_get_type_name(this_node->
650                                                                     type),
651                                               acpi_ut_get_type_name
652                                               (type_to_check_for)));
653                         }
654
655                         /*
656                          * If this is the last name segment and we are not looking for a
657                          * specific type, but the type of found object is known, use that
658                          * type to (later) see if it opens a scope.
659                          */
660                         if (type == ACPI_TYPE_ANY) {
661                                 type = this_node->type;
662                         }
663                 }
664
665                 /* Point to next name segment and make this node current */
666
667                 path += ACPI_NAME_SIZE;
668                 current_node = this_node;
669         }
670
671         /* Always check if we need to open a new scope */
672
673         if (!(flags & ACPI_NS_DONT_OPEN_SCOPE) && (walk_state)) {
674                 /*
675                  * If entry is a type which opens a scope, push the new scope on the
676                  * scope stack.
677                  */
678                 if (acpi_ns_opens_scope(type)) {
679                         status =
680                             acpi_ds_scope_stack_push(this_node, type,
681                                                      walk_state);
682                         if (ACPI_FAILURE(status)) {
683                                 return_ACPI_STATUS(status);
684                         }
685                 }
686         }
687 #ifdef ACPI_EXEC_APP
688         if (flags & ACPI_NS_EARLY_INIT) {
689                 this_node->flags |= ANOBJ_NODE_EARLY_INIT;
690         }
691 #endif
692
693         *return_node = this_node;
694         return_ACPI_STATUS(AE_OK);
695 }