ipv6: fix race condition regarding dst->expires and dst->from.
[pandora-kernel.git] / drivers / acpi / acpica / utdelete.c
1 /*******************************************************************************
2  *
3  * Module Name: utdelete - object deletion and reference count utilities
4  *
5  ******************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2012, 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 "acinterp.h"
47 #include "acnamesp.h"
48 #include "acevents.h"
49
50 #define _COMPONENT          ACPI_UTILITIES
51 ACPI_MODULE_NAME("utdelete")
52
53 /* Local prototypes */
54 static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);
55
56 static void
57 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action);
58
59 /*******************************************************************************
60  *
61  * FUNCTION:    acpi_ut_delete_internal_obj
62  *
63  * PARAMETERS:  object         - Object to be deleted
64  *
65  * RETURN:      None
66  *
67  * DESCRIPTION: Low level object deletion, after reference counts have been
68  *              updated (All reference counts, including sub-objects!)
69  *
70  ******************************************************************************/
71
72 static void acpi_ut_delete_internal_obj(union acpi_operand_object *object)
73 {
74         void *obj_pointer = NULL;
75         union acpi_operand_object *handler_desc;
76         union acpi_operand_object *second_desc;
77         union acpi_operand_object *next_desc;
78         union acpi_operand_object **last_obj_ptr;
79
80         ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);
81
82         if (!object) {
83                 return_VOID;
84         }
85
86         /*
87          * Must delete or free any pointers within the object that are not
88          * actual ACPI objects (for example, a raw buffer pointer).
89          */
90         switch (object->common.type) {
91         case ACPI_TYPE_STRING:
92
93                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
94                                   "**** String %p, ptr %p\n", object,
95                                   object->string.pointer));
96
97                 /* Free the actual string buffer */
98
99                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
100
101                         /* But only if it is NOT a pointer into an ACPI table */
102
103                         obj_pointer = object->string.pointer;
104                 }
105                 break;
106
107         case ACPI_TYPE_BUFFER:
108
109                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
110                                   "**** Buffer %p, ptr %p\n", object,
111                                   object->buffer.pointer));
112
113                 /* Free the actual buffer */
114
115                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
116
117                         /* But only if it is NOT a pointer into an ACPI table */
118
119                         obj_pointer = object->buffer.pointer;
120                 }
121                 break;
122
123         case ACPI_TYPE_PACKAGE:
124
125                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
126                                   " **** Package of count %X\n",
127                                   object->package.count));
128
129                 /*
130                  * Elements of the package are not handled here, they are deleted
131                  * separately
132                  */
133
134                 /* Free the (variable length) element pointer array */
135
136                 obj_pointer = object->package.elements;
137                 break;
138
139                 /*
140                  * These objects have a possible list of notify handlers.
141                  * Device object also may have a GPE block.
142                  */
143         case ACPI_TYPE_DEVICE:
144
145                 if (object->device.gpe_block) {
146                         (void)acpi_ev_delete_gpe_block(object->device.
147                                                        gpe_block);
148                 }
149
150                 /*lint -fallthrough */
151
152         case ACPI_TYPE_PROCESSOR:
153         case ACPI_TYPE_THERMAL:
154
155                 /* Walk the address handler list for this object */
156
157                 handler_desc = object->common_notify.handler;
158                 while (handler_desc) {
159                         next_desc = handler_desc->address_space.next;
160                         acpi_ut_remove_reference(handler_desc);
161                         handler_desc = next_desc;
162                 }
163                 break;
164
165         case ACPI_TYPE_MUTEX:
166
167                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
168                                   "***** Mutex %p, OS Mutex %p\n",
169                                   object, object->mutex.os_mutex));
170
171                 if (object == acpi_gbl_global_lock_mutex) {
172
173                         /* Global Lock has extra semaphore */
174
175                         (void)
176                             acpi_os_delete_semaphore
177                             (acpi_gbl_global_lock_semaphore);
178                         acpi_gbl_global_lock_semaphore = NULL;
179
180                         acpi_os_delete_mutex(object->mutex.os_mutex);
181                         acpi_gbl_global_lock_mutex = NULL;
182                 } else {
183                         acpi_ex_unlink_mutex(object);
184                         acpi_os_delete_mutex(object->mutex.os_mutex);
185                 }
186                 break;
187
188         case ACPI_TYPE_EVENT:
189
190                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
191                                   "***** Event %p, OS Semaphore %p\n",
192                                   object, object->event.os_semaphore));
193
194                 (void)acpi_os_delete_semaphore(object->event.os_semaphore);
195                 object->event.os_semaphore = NULL;
196                 break;
197
198         case ACPI_TYPE_METHOD:
199
200                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
201                                   "***** Method %p\n", object));
202
203                 /* Delete the method mutex if it exists */
204
205                 if (object->method.mutex) {
206                         acpi_os_delete_mutex(object->method.mutex->mutex.
207                                              os_mutex);
208                         acpi_ut_delete_object_desc(object->method.mutex);
209                         object->method.mutex = NULL;
210                 }
211                 break;
212
213         case ACPI_TYPE_REGION:
214
215                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
216                                   "***** Region %p\n", object));
217
218                 /*
219                  * Update address_range list. However, only permanent regions
220                  * are installed in this list. (Not created within a method)
221                  */
222                 if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
223                         acpi_ut_remove_address_range(object->region.space_id,
224                                                      object->region.node);
225                 }
226
227                 second_desc = acpi_ns_get_secondary_object(object);
228                 if (second_desc) {
229                         /*
230                          * Free the region_context if and only if the handler is one of the
231                          * default handlers -- and therefore, we created the context object
232                          * locally, it was not created by an external caller.
233                          */
234                         handler_desc = object->region.handler;
235                         if (handler_desc) {
236                                 next_desc =
237                                     handler_desc->address_space.region_list;
238                                 last_obj_ptr =
239                                     &handler_desc->address_space.region_list;
240
241                                 /* Remove the region object from the handler's list */
242
243                                 while (next_desc) {
244                                         if (next_desc == object) {
245                                                 *last_obj_ptr =
246                                                     next_desc->region.next;
247                                                 break;
248                                         }
249
250                                         /* Walk the linked list of handler */
251
252                                         last_obj_ptr = &next_desc->region.next;
253                                         next_desc = next_desc->region.next;
254                                 }
255
256                                 if (handler_desc->address_space.handler_flags &
257                                     ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
258
259                                         /* Deactivate region and free region context */
260
261                                         if (handler_desc->address_space.setup) {
262                                                 (void)handler_desc->
263                                                     address_space.setup(object,
264                                                                         ACPI_REGION_DEACTIVATE,
265                                                                         handler_desc->
266                                                                         address_space.
267                                                                         context,
268                                                                         &second_desc->
269                                                                         extra.
270                                                                         region_context);
271                                         }
272                                 }
273
274                                 acpi_ut_remove_reference(handler_desc);
275                         }
276
277                         /* Now we can free the Extra object */
278
279                         acpi_ut_delete_object_desc(second_desc);
280                 }
281                 break;
282
283         case ACPI_TYPE_BUFFER_FIELD:
284
285                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
286                                   "***** Buffer Field %p\n", object));
287
288                 second_desc = acpi_ns_get_secondary_object(object);
289                 if (second_desc) {
290                         acpi_ut_delete_object_desc(second_desc);
291                 }
292                 break;
293
294         case ACPI_TYPE_LOCAL_BANK_FIELD:
295
296                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
297                                   "***** Bank Field %p\n", object));
298
299                 second_desc = acpi_ns_get_secondary_object(object);
300                 if (second_desc) {
301                         acpi_ut_delete_object_desc(second_desc);
302                 }
303                 break;
304
305         default:
306                 break;
307         }
308
309         /* Free any allocated memory (pointer within the object) found above */
310
311         if (obj_pointer) {
312                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
313                                   "Deleting Object Subptr %p\n", obj_pointer));
314                 ACPI_FREE(obj_pointer);
315         }
316
317         /* Now the object can be safely deleted */
318
319         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
320                           object, acpi_ut_get_object_type_name(object)));
321
322         acpi_ut_delete_object_desc(object);
323         return_VOID;
324 }
325
326 /*******************************************************************************
327  *
328  * FUNCTION:    acpi_ut_delete_internal_object_list
329  *
330  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
331  *
332  * RETURN:      None
333  *
334  * DESCRIPTION: This function deletes an internal object list, including both
335  *              simple objects and package objects
336  *
337  ******************************************************************************/
338
339 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
340 {
341         union acpi_operand_object **internal_obj;
342
343         ACPI_FUNCTION_TRACE(ut_delete_internal_object_list);
344
345         /* Walk the null-terminated internal list */
346
347         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
348                 acpi_ut_remove_reference(*internal_obj);
349         }
350
351         /* Free the combined parameter pointer list and object array */
352
353         ACPI_FREE(obj_list);
354         return_VOID;
355 }
356
357 /*******************************************************************************
358  *
359  * FUNCTION:    acpi_ut_update_ref_count
360  *
361  * PARAMETERS:  object          - Object whose ref count is to be updated
362  *              action          - What to do
363  *
364  * RETURN:      New ref count
365  *
366  * DESCRIPTION: Modify the ref count and return it.
367  *
368  ******************************************************************************/
369
370 static void
371 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
372 {
373         u16 count;
374         u16 new_count;
375
376         ACPI_FUNCTION_NAME(ut_update_ref_count);
377
378         if (!object) {
379                 return;
380         }
381
382         count = object->common.reference_count;
383         new_count = count;
384
385         /*
386          * Perform the reference count action (increment, decrement, force delete)
387          */
388         switch (action) {
389         case REF_INCREMENT:
390
391                 new_count++;
392                 object->common.reference_count = new_count;
393
394                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
395                                   "Obj %p Refs=%X, [Incremented]\n",
396                                   object, new_count));
397                 break;
398
399         case REF_DECREMENT:
400
401                 if (count < 1) {
402                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
403                                           "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
404                                           object, new_count));
405
406                         new_count = 0;
407                 } else {
408                         new_count--;
409
410                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
411                                           "Obj %p Refs=%X, [Decremented]\n",
412                                           object, new_count));
413                 }
414
415                 if (object->common.type == ACPI_TYPE_METHOD) {
416                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
417                                           "Method Obj %p Refs=%X, [Decremented]\n",
418                                           object, new_count));
419                 }
420
421                 object->common.reference_count = new_count;
422                 if (new_count == 0) {
423                         acpi_ut_delete_internal_obj(object);
424                 }
425                 break;
426
427         case REF_FORCE_DELETE:
428
429                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
430                                   "Obj %p Refs=%X, Force delete! (Set to 0)\n",
431                                   object, count));
432
433                 new_count = 0;
434                 object->common.reference_count = new_count;
435                 acpi_ut_delete_internal_obj(object);
436                 break;
437
438         default:
439
440                 ACPI_ERROR((AE_INFO, "Unknown action (0x%X)", action));
441                 break;
442         }
443
444         /*
445          * Sanity check the reference count, for debug purposes only.
446          * (A deleted object will have a huge reference count)
447          */
448         if (count > ACPI_MAX_REFERENCE_COUNT) {
449                 ACPI_WARNING((AE_INFO,
450                               "Large Reference Count (0x%X) in object %p",
451                               count, object));
452         }
453 }
454
455 /*******************************************************************************
456  *
457  * FUNCTION:    acpi_ut_update_object_reference
458  *
459  * PARAMETERS:  object              - Increment ref count for this object
460  *                                    and all sub-objects
461  *              action              - Either REF_INCREMENT or REF_DECREMENT or
462  *                                    REF_FORCE_DELETE
463  *
464  * RETURN:      Status
465  *
466  * DESCRIPTION: Increment the object reference count
467  *
468  * Object references are incremented when:
469  * 1) An object is attached to a Node (namespace object)
470  * 2) An object is copied (all subobjects must be incremented)
471  *
472  * Object references are decremented when:
473  * 1) An object is detached from an Node
474  *
475  ******************************************************************************/
476
477 acpi_status
478 acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
479 {
480         acpi_status status = AE_OK;
481         union acpi_generic_state *state_list = NULL;
482         union acpi_operand_object *next_object = NULL;
483         union acpi_operand_object *prev_object;
484         union acpi_generic_state *state;
485         u32 i;
486
487         ACPI_FUNCTION_TRACE_PTR(ut_update_object_reference, object);
488
489         while (object) {
490
491                 /* Make sure that this isn't a namespace handle */
492
493                 if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
494                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
495                                           "Object %p is NS handle\n", object));
496                         return_ACPI_STATUS(AE_OK);
497                 }
498
499                 /*
500                  * All sub-objects must have their reference count incremented also.
501                  * Different object types have different subobjects.
502                  */
503                 switch (object->common.type) {
504                 case ACPI_TYPE_DEVICE:
505                 case ACPI_TYPE_PROCESSOR:
506                 case ACPI_TYPE_POWER:
507                 case ACPI_TYPE_THERMAL:
508
509                         /*
510                          * Update the notify objects for these types (if present)
511                          * Two lists, system and device notify handlers.
512                          */
513                         for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
514                                 prev_object =
515                                     object->common_notify.notify_list[i];
516                                 while (prev_object) {
517                                         next_object =
518                                             prev_object->notify.next[i];
519                                         acpi_ut_update_ref_count(prev_object,
520                                                                  action);
521                                         prev_object = next_object;
522                                 }
523                         }
524                         break;
525
526                 case ACPI_TYPE_PACKAGE:
527                         /*
528                          * We must update all the sub-objects of the package,
529                          * each of whom may have their own sub-objects.
530                          */
531                         for (i = 0; i < object->package.count; i++) {
532                                 /*
533                                  * Push each element onto the stack for later processing.
534                                  * Note: There can be null elements within the package,
535                                  * these are simply ignored
536                                  */
537                                 status =
538                                     acpi_ut_create_update_state_and_push
539                                     (object->package.elements[i], action,
540                                      &state_list);
541                                 if (ACPI_FAILURE(status)) {
542                                         goto error_exit;
543                                 }
544                         }
545                         break;
546
547                 case ACPI_TYPE_BUFFER_FIELD:
548
549                         next_object = object->buffer_field.buffer_obj;
550                         break;
551
552                 case ACPI_TYPE_LOCAL_REGION_FIELD:
553
554                         next_object = object->field.region_obj;
555                         break;
556
557                 case ACPI_TYPE_LOCAL_BANK_FIELD:
558
559                         next_object = object->bank_field.bank_obj;
560                         status =
561                             acpi_ut_create_update_state_and_push(object->
562                                                                  bank_field.
563                                                                  region_obj,
564                                                                  action,
565                                                                  &state_list);
566                         if (ACPI_FAILURE(status)) {
567                                 goto error_exit;
568                         }
569                         break;
570
571                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
572
573                         next_object = object->index_field.index_obj;
574                         status =
575                             acpi_ut_create_update_state_and_push(object->
576                                                                  index_field.
577                                                                  data_obj,
578                                                                  action,
579                                                                  &state_list);
580                         if (ACPI_FAILURE(status)) {
581                                 goto error_exit;
582                         }
583                         break;
584
585                 case ACPI_TYPE_LOCAL_REFERENCE:
586                         /*
587                          * The target of an Index (a package, string, or buffer) or a named
588                          * reference must track changes to the ref count of the index or
589                          * target object.
590                          */
591                         if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
592                             (object->reference.class == ACPI_REFCLASS_NAME)) {
593                                 next_object = object->reference.object;
594                         }
595                         break;
596
597                 case ACPI_TYPE_REGION:
598                 default:
599                         break;  /* No subobjects for all other types */
600                 }
601
602                 /*
603                  * Now we can update the count in the main object. This can only
604                  * happen after we update the sub-objects in case this causes the
605                  * main object to be deleted.
606                  */
607                 acpi_ut_update_ref_count(object, action);
608                 object = NULL;
609
610                 /* Move on to the next object to be updated */
611
612                 if (next_object) {
613                         object = next_object;
614                         next_object = NULL;
615                 } else if (state_list) {
616                         state = acpi_ut_pop_generic_state(&state_list);
617                         object = state->update.object;
618                         acpi_ut_delete_generic_state(state);
619                 }
620         }
621
622         return_ACPI_STATUS(AE_OK);
623
624       error_exit:
625
626         ACPI_EXCEPTION((AE_INFO, status,
627                         "Could not update object reference count"));
628
629         /* Free any stacked Update State objects */
630
631         while (state_list) {
632                 state = acpi_ut_pop_generic_state(&state_list);
633                 acpi_ut_delete_generic_state(state);
634         }
635
636         return_ACPI_STATUS(status);
637 }
638
639 /*******************************************************************************
640  *
641  * FUNCTION:    acpi_ut_add_reference
642  *
643  * PARAMETERS:  object          - Object whose reference count is to be
644  *                                incremented
645  *
646  * RETURN:      None
647  *
648  * DESCRIPTION: Add one reference to an ACPI object
649  *
650  ******************************************************************************/
651
652 void acpi_ut_add_reference(union acpi_operand_object *object)
653 {
654
655         ACPI_FUNCTION_TRACE_PTR(ut_add_reference, object);
656
657         /* Ensure that we have a valid object */
658
659         if (!acpi_ut_valid_internal_object(object)) {
660                 return_VOID;
661         }
662
663         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
664                           "Obj %p Current Refs=%X [To Be Incremented]\n",
665                           object, object->common.reference_count));
666
667         /* Increment the reference count */
668
669         (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
670         return_VOID;
671 }
672
673 /*******************************************************************************
674  *
675  * FUNCTION:    acpi_ut_remove_reference
676  *
677  * PARAMETERS:  object         - Object whose ref count will be decremented
678  *
679  * RETURN:      None
680  *
681  * DESCRIPTION: Decrement the reference count of an ACPI internal object
682  *
683  ******************************************************************************/
684
685 void acpi_ut_remove_reference(union acpi_operand_object *object)
686 {
687
688         ACPI_FUNCTION_TRACE_PTR(ut_remove_reference, object);
689
690         /*
691          * Allow a NULL pointer to be passed in, just ignore it. This saves
692          * each caller from having to check. Also, ignore NS nodes.
693          *
694          */
695         if (!object ||
696             (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
697                 return_VOID;
698         }
699
700         /* Ensure that we have a valid object */
701
702         if (!acpi_ut_valid_internal_object(object)) {
703                 return_VOID;
704         }
705
706         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
707                           "Obj %p Current Refs=%X [To Be Decremented]\n",
708                           object, object->common.reference_count));
709
710         /*
711          * Decrement the reference count, and only actually delete the object
712          * if the reference count becomes 0. (Must also decrement the ref count
713          * of all subobjects!)
714          */
715         (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
716         return_VOID;
717 }