1/*******************************************************************************
2 *
3 * Module Name: utdelete - object deletion and reference count utilities
4 *
5 ******************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2015, 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
51ACPI_MODULE_NAME("utdelete")
52
53/* Local prototypes */
54static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);
55
56static void
57acpi_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
72static 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 *start_desc;
79	union acpi_operand_object **last_obj_ptr;
80
81	ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);
82
83	if (!object) {
84		return_VOID;
85	}
86
87	/*
88	 * Must delete or free any pointers within the object that are not
89	 * actual ACPI objects (for example, a raw buffer pointer).
90	 */
91	switch (object->common.type) {
92	case ACPI_TYPE_STRING:
93
94		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
95				  "**** String %p, ptr %p\n", object,
96				  object->string.pointer));
97
98		/* Free the actual string buffer */
99
100		if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
101
102			/* But only if it is NOT a pointer into an ACPI table */
103
104			obj_pointer = object->string.pointer;
105		}
106		break;
107
108	case ACPI_TYPE_BUFFER:
109
110		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
111				  "**** Buffer %p, ptr %p\n", object,
112				  object->buffer.pointer));
113
114		/* Free the actual buffer */
115
116		if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
117
118			/* But only if it is NOT a pointer into an ACPI table */
119
120			obj_pointer = object->buffer.pointer;
121		}
122		break;
123
124	case ACPI_TYPE_PACKAGE:
125
126		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
127				  " **** Package of count %X\n",
128				  object->package.count));
129
130		/*
131		 * Elements of the package are not handled here, they are deleted
132		 * separately
133		 */
134
135		/* Free the (variable length) element pointer array */
136
137		obj_pointer = object->package.elements;
138		break;
139
140		/*
141		 * These objects have a possible list of notify handlers.
142		 * Device object also may have a GPE block.
143		 */
144	case ACPI_TYPE_DEVICE:
145
146		if (object->device.gpe_block) {
147			(void)acpi_ev_delete_gpe_block(object->device.
148						       gpe_block);
149		}
150
151		/*lint -fallthrough */
152
153	case ACPI_TYPE_PROCESSOR:
154	case ACPI_TYPE_THERMAL:
155
156		/* Walk the address handler list for this object */
157
158		handler_desc = object->common_notify.handler;
159		while (handler_desc) {
160			next_desc = handler_desc->address_space.next;
161			acpi_ut_remove_reference(handler_desc);
162			handler_desc = next_desc;
163		}
164		break;
165
166	case ACPI_TYPE_MUTEX:
167
168		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
169				  "***** Mutex %p, OS Mutex %p\n",
170				  object, object->mutex.os_mutex));
171
172		if (object == acpi_gbl_global_lock_mutex) {
173
174			/* Global Lock has extra semaphore */
175
176			(void)
177			    acpi_os_delete_semaphore
178			    (acpi_gbl_global_lock_semaphore);
179			acpi_gbl_global_lock_semaphore = NULL;
180
181			acpi_os_delete_mutex(object->mutex.os_mutex);
182			acpi_gbl_global_lock_mutex = NULL;
183		} else {
184			acpi_ex_unlink_mutex(object);
185			acpi_os_delete_mutex(object->mutex.os_mutex);
186		}
187		break;
188
189	case ACPI_TYPE_EVENT:
190
191		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
192				  "***** Event %p, OS Semaphore %p\n",
193				  object, object->event.os_semaphore));
194
195		(void)acpi_os_delete_semaphore(object->event.os_semaphore);
196		object->event.os_semaphore = NULL;
197		break;
198
199	case ACPI_TYPE_METHOD:
200
201		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
202				  "***** Method %p\n", object));
203
204		/* Delete the method mutex if it exists */
205
206		if (object->method.mutex) {
207			acpi_os_delete_mutex(object->method.mutex->mutex.
208					     os_mutex);
209			acpi_ut_delete_object_desc(object->method.mutex);
210			object->method.mutex = NULL;
211		}
212		if (object->method.node) {
213			object->method.node = NULL;
214		}
215		break;
216
217	case ACPI_TYPE_REGION:
218
219		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
220				  "***** Region %p\n", object));
221
222		/*
223		 * Update address_range list. However, only permanent regions
224		 * are installed in this list. (Not created within a method)
225		 */
226		if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
227			acpi_ut_remove_address_range(object->region.space_id,
228						     object->region.node);
229		}
230
231		second_desc = acpi_ns_get_secondary_object(object);
232		if (second_desc) {
233			/*
234			 * Free the region_context if and only if the handler is one of the
235			 * default handlers -- and therefore, we created the context object
236			 * locally, it was not created by an external caller.
237			 */
238			handler_desc = object->region.handler;
239			if (handler_desc) {
240				next_desc =
241				    handler_desc->address_space.region_list;
242				start_desc = next_desc;
243				last_obj_ptr =
244				    &handler_desc->address_space.region_list;
245
246				/* Remove the region object from the handler list */
247
248				while (next_desc) {
249					if (next_desc == object) {
250						*last_obj_ptr =
251						    next_desc->region.next;
252						break;
253					}
254
255					/* Walk the linked list of handlers */
256
257					last_obj_ptr = &next_desc->region.next;
258					next_desc = next_desc->region.next;
259
260					/* Prevent infinite loop if list is corrupted */
261
262					if (next_desc == start_desc) {
263						ACPI_ERROR((AE_INFO,
264							    "Circular region list in address handler object %p",
265							    handler_desc));
266						return_VOID;
267					}
268				}
269
270				if (handler_desc->address_space.handler_flags &
271				    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
272
273					/* Deactivate region and free region context */
274
275					if (handler_desc->address_space.setup) {
276						(void)handler_desc->
277						    address_space.setup(object,
278									ACPI_REGION_DEACTIVATE,
279									handler_desc->
280									address_space.
281									context,
282									&second_desc->
283									extra.
284									region_context);
285					}
286				}
287
288				acpi_ut_remove_reference(handler_desc);
289			}
290
291			/* Now we can free the Extra object */
292
293			acpi_ut_delete_object_desc(second_desc);
294		}
295		break;
296
297	case ACPI_TYPE_BUFFER_FIELD:
298
299		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
300				  "***** Buffer Field %p\n", object));
301
302		second_desc = acpi_ns_get_secondary_object(object);
303		if (second_desc) {
304			acpi_ut_delete_object_desc(second_desc);
305		}
306		break;
307
308	case ACPI_TYPE_LOCAL_BANK_FIELD:
309
310		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
311				  "***** Bank Field %p\n", object));
312
313		second_desc = acpi_ns_get_secondary_object(object);
314		if (second_desc) {
315			acpi_ut_delete_object_desc(second_desc);
316		}
317		break;
318
319	default:
320
321		break;
322	}
323
324	/* Free any allocated memory (pointer within the object) found above */
325
326	if (obj_pointer) {
327		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
328				  "Deleting Object Subptr %p\n", obj_pointer));
329		ACPI_FREE(obj_pointer);
330	}
331
332	/* Now the object can be safely deleted */
333
334	ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
335			  object, acpi_ut_get_object_type_name(object)));
336
337	acpi_ut_delete_object_desc(object);
338	return_VOID;
339}
340
341/*******************************************************************************
342 *
343 * FUNCTION:    acpi_ut_delete_internal_object_list
344 *
345 * PARAMETERS:  obj_list        - Pointer to the list to be deleted
346 *
347 * RETURN:      None
348 *
349 * DESCRIPTION: This function deletes an internal object list, including both
350 *              simple objects and package objects
351 *
352 ******************************************************************************/
353
354void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
355{
356	union acpi_operand_object **internal_obj;
357
358	ACPI_FUNCTION_ENTRY();
359
360	/* Walk the null-terminated internal list */
361
362	for (internal_obj = obj_list; *internal_obj; internal_obj++) {
363		acpi_ut_remove_reference(*internal_obj);
364	}
365
366	/* Free the combined parameter pointer list and object array */
367
368	ACPI_FREE(obj_list);
369	return;
370}
371
372/*******************************************************************************
373 *
374 * FUNCTION:    acpi_ut_update_ref_count
375 *
376 * PARAMETERS:  object          - Object whose ref count is to be updated
377 *              action          - What to do (REF_INCREMENT or REF_DECREMENT)
378 *
379 * RETURN:      None. Sets new reference count within the object
380 *
381 * DESCRIPTION: Modify the reference count for an internal acpi object
382 *
383 ******************************************************************************/
384
385static void
386acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
387{
388	u16 original_count;
389	u16 new_count = 0;
390	acpi_cpu_flags lock_flags;
391
392	ACPI_FUNCTION_NAME(ut_update_ref_count);
393
394	if (!object) {
395		return;
396	}
397
398	/*
399	 * Always get the reference count lock. Note: Interpreter and/or
400	 * Namespace is not always locked when this function is called.
401	 */
402	lock_flags = acpi_os_acquire_lock(acpi_gbl_reference_count_lock);
403	original_count = object->common.reference_count;
404
405	/* Perform the reference count action (increment, decrement) */
406
407	switch (action) {
408	case REF_INCREMENT:
409
410		new_count = original_count + 1;
411		object->common.reference_count = new_count;
412		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
413
414		/* The current reference count should never be zero here */
415
416		if (!original_count) {
417			ACPI_WARNING((AE_INFO,
418				      "Obj %p, Reference Count was zero before increment\n",
419				      object));
420		}
421
422		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
423				  "Obj %p Type %.2X Refs %.2X [Incremented]\n",
424				  object, object->common.type, new_count));
425		break;
426
427	case REF_DECREMENT:
428
429		/* The current reference count must be non-zero */
430
431		if (original_count) {
432			new_count = original_count - 1;
433			object->common.reference_count = new_count;
434		}
435
436		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
437
438		if (!original_count) {
439			ACPI_WARNING((AE_INFO,
440				      "Obj %p, Reference Count is already zero, cannot decrement\n",
441				      object));
442		}
443
444		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
445				  "Obj %p Type %.2X Refs %.2X [Decremented]\n",
446				  object, object->common.type, new_count));
447
448		/* Actually delete the object on a reference count of zero */
449
450		if (new_count == 0) {
451			acpi_ut_delete_internal_obj(object);
452		}
453		break;
454
455	default:
456
457		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
458		ACPI_ERROR((AE_INFO, "Unknown Reference Count action (0x%X)",
459			    action));
460		return;
461	}
462
463	/*
464	 * Sanity check the reference count, for debug purposes only.
465	 * (A deleted object will have a huge reference count)
466	 */
467	if (new_count > ACPI_MAX_REFERENCE_COUNT) {
468		ACPI_WARNING((AE_INFO,
469			      "Large Reference Count (0x%X) in object %p, Type=0x%.2X",
470			      new_count, object, object->common.type));
471	}
472}
473
474/*******************************************************************************
475 *
476 * FUNCTION:    acpi_ut_update_object_reference
477 *
478 * PARAMETERS:  object              - Increment ref count for this object
479 *                                    and all sub-objects
480 *              action              - Either REF_INCREMENT or REF_DECREMENT
481 *
482 * RETURN:      Status
483 *
484 * DESCRIPTION: Increment the object reference count
485 *
486 * Object references are incremented when:
487 * 1) An object is attached to a Node (namespace object)
488 * 2) An object is copied (all subobjects must be incremented)
489 *
490 * Object references are decremented when:
491 * 1) An object is detached from an Node
492 *
493 ******************************************************************************/
494
495acpi_status
496acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
497{
498	acpi_status status = AE_OK;
499	union acpi_generic_state *state_list = NULL;
500	union acpi_operand_object *next_object = NULL;
501	union acpi_operand_object *prev_object;
502	union acpi_generic_state *state;
503	u32 i;
504
505	ACPI_FUNCTION_NAME(ut_update_object_reference);
506
507	while (object) {
508
509		/* Make sure that this isn't a namespace handle */
510
511		if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
512			ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
513					  "Object %p is NS handle\n", object));
514			return (AE_OK);
515		}
516
517		/*
518		 * All sub-objects must have their reference count incremented also.
519		 * Different object types have different subobjects.
520		 */
521		switch (object->common.type) {
522		case ACPI_TYPE_DEVICE:
523		case ACPI_TYPE_PROCESSOR:
524		case ACPI_TYPE_POWER:
525		case ACPI_TYPE_THERMAL:
526			/*
527			 * Update the notify objects for these types (if present)
528			 * Two lists, system and device notify handlers.
529			 */
530			for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
531				prev_object =
532				    object->common_notify.notify_list[i];
533				while (prev_object) {
534					next_object =
535					    prev_object->notify.next[i];
536					acpi_ut_update_ref_count(prev_object,
537								 action);
538					prev_object = next_object;
539				}
540			}
541			break;
542
543		case ACPI_TYPE_PACKAGE:
544			/*
545			 * We must update all the sub-objects of the package,
546			 * each of whom may have their own sub-objects.
547			 */
548			for (i = 0; i < object->package.count; i++) {
549				/*
550				 * Null package elements are legal and can be simply
551				 * ignored.
552				 */
553				next_object = object->package.elements[i];
554				if (!next_object) {
555					continue;
556				}
557
558				switch (next_object->common.type) {
559				case ACPI_TYPE_INTEGER:
560				case ACPI_TYPE_STRING:
561				case ACPI_TYPE_BUFFER:
562					/*
563					 * For these very simple sub-objects, we can just
564					 * update the reference count here and continue.
565					 * Greatly increases performance of this operation.
566					 */
567					acpi_ut_update_ref_count(next_object,
568								 action);
569					break;
570
571				default:
572					/*
573					 * For complex sub-objects, push them onto the stack
574					 * for later processing (this eliminates recursion.)
575					 */
576					status =
577					    acpi_ut_create_update_state_and_push
578					    (next_object, action, &state_list);
579					if (ACPI_FAILURE(status)) {
580						goto error_exit;
581					}
582					break;
583				}
584			}
585			next_object = NULL;
586			break;
587
588		case ACPI_TYPE_BUFFER_FIELD:
589
590			next_object = object->buffer_field.buffer_obj;
591			break;
592
593		case ACPI_TYPE_LOCAL_REGION_FIELD:
594
595			next_object = object->field.region_obj;
596			break;
597
598		case ACPI_TYPE_LOCAL_BANK_FIELD:
599
600			next_object = object->bank_field.bank_obj;
601			status =
602			    acpi_ut_create_update_state_and_push(object->
603								 bank_field.
604								 region_obj,
605								 action,
606								 &state_list);
607			if (ACPI_FAILURE(status)) {
608				goto error_exit;
609			}
610			break;
611
612		case ACPI_TYPE_LOCAL_INDEX_FIELD:
613
614			next_object = object->index_field.index_obj;
615			status =
616			    acpi_ut_create_update_state_and_push(object->
617								 index_field.
618								 data_obj,
619								 action,
620								 &state_list);
621			if (ACPI_FAILURE(status)) {
622				goto error_exit;
623			}
624			break;
625
626		case ACPI_TYPE_LOCAL_REFERENCE:
627			/*
628			 * The target of an Index (a package, string, or buffer) or a named
629			 * reference must track changes to the ref count of the index or
630			 * target object.
631			 */
632			if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
633			    (object->reference.class == ACPI_REFCLASS_NAME)) {
634				next_object = object->reference.object;
635			}
636			break;
637
638		case ACPI_TYPE_REGION:
639		default:
640
641			break;	/* No subobjects for all other types */
642		}
643
644		/*
645		 * Now we can update the count in the main object. This can only
646		 * happen after we update the sub-objects in case this causes the
647		 * main object to be deleted.
648		 */
649		acpi_ut_update_ref_count(object, action);
650		object = NULL;
651
652		/* Move on to the next object to be updated */
653
654		if (next_object) {
655			object = next_object;
656			next_object = NULL;
657		} else if (state_list) {
658			state = acpi_ut_pop_generic_state(&state_list);
659			object = state->update.object;
660			acpi_ut_delete_generic_state(state);
661		}
662	}
663
664	return (AE_OK);
665
666error_exit:
667
668	ACPI_EXCEPTION((AE_INFO, status,
669			"Could not update object reference count"));
670
671	/* Free any stacked Update State objects */
672
673	while (state_list) {
674		state = acpi_ut_pop_generic_state(&state_list);
675		acpi_ut_delete_generic_state(state);
676	}
677
678	return (status);
679}
680
681/*******************************************************************************
682 *
683 * FUNCTION:    acpi_ut_add_reference
684 *
685 * PARAMETERS:  object          - Object whose reference count is to be
686 *                                incremented
687 *
688 * RETURN:      None
689 *
690 * DESCRIPTION: Add one reference to an ACPI object
691 *
692 ******************************************************************************/
693
694void acpi_ut_add_reference(union acpi_operand_object *object)
695{
696
697	ACPI_FUNCTION_NAME(ut_add_reference);
698
699	/* Ensure that we have a valid object */
700
701	if (!acpi_ut_valid_internal_object(object)) {
702		return;
703	}
704
705	ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
706			  "Obj %p Current Refs=%X [To Be Incremented]\n",
707			  object, object->common.reference_count));
708
709	/* Increment the reference count */
710
711	(void)acpi_ut_update_object_reference(object, REF_INCREMENT);
712	return;
713}
714
715/*******************************************************************************
716 *
717 * FUNCTION:    acpi_ut_remove_reference
718 *
719 * PARAMETERS:  object         - Object whose ref count will be decremented
720 *
721 * RETURN:      None
722 *
723 * DESCRIPTION: Decrement the reference count of an ACPI internal object
724 *
725 ******************************************************************************/
726
727void acpi_ut_remove_reference(union acpi_operand_object *object)
728{
729
730	ACPI_FUNCTION_NAME(ut_remove_reference);
731
732	/*
733	 * Allow a NULL pointer to be passed in, just ignore it. This saves
734	 * each caller from having to check. Also, ignore NS nodes.
735	 */
736	if (!object ||
737	    (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
738		return;
739	}
740
741	/* Ensure that we have a valid object */
742
743	if (!acpi_ut_valid_internal_object(object)) {
744		return;
745	}
746
747	ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
748			  "Obj %p Current Refs=%X [To Be Decremented]\n",
749			  object, object->common.reference_count));
750
751	/*
752	 * Decrement the reference count, and only actually delete the object
753	 * if the reference count becomes 0. (Must also decrement the ref count
754	 * of all subobjects!)
755	 */
756	(void)acpi_ut_update_object_reference(object, REF_DECREMENT);
757	return;
758}
759