1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/*******************************************************************************
3 *
4 * Module Name: utdelete - object deletion and reference count utilities
5 *
6 ******************************************************************************/
7
8#include <acpi/acpi.h>
9#include "accommon.h"
10#include "acinterp.h"
11#include "acnamesp.h"
12#include "acevents.h"
13
14#define _COMPONENT          ACPI_UTILITIES
15ACPI_MODULE_NAME("utdelete")
16
17/* Local prototypes */
18static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);
19
20static void
21acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action);
22
23/*******************************************************************************
24 *
25 * FUNCTION:    acpi_ut_delete_internal_obj
26 *
27 * PARAMETERS:  object         - Object to be deleted
28 *
29 * RETURN:      None
30 *
31 * DESCRIPTION: Low level object deletion, after reference counts have been
32 *              updated (All reference counts, including sub-objects!)
33 *
34 ******************************************************************************/
35
36static void acpi_ut_delete_internal_obj(union acpi_operand_object *object)
37{
38	void *obj_pointer = NULL;
39	union acpi_operand_object *handler_desc;
40	union acpi_operand_object *second_desc;
41	union acpi_operand_object *next_desc;
42	union acpi_operand_object *start_desc;
43	union acpi_operand_object **last_obj_ptr;
44
45	ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);
46
47	if (!object) {
48		return_VOID;
49	}
50
51	/*
52	 * Must delete or free any pointers within the object that are not
53	 * actual ACPI objects (for example, a raw buffer pointer).
54	 */
55	switch (object->common.type) {
56	case ACPI_TYPE_STRING:
57
58		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
59				  "**** String %p, ptr %p\n", object,
60				  object->string.pointer));
61
62		/* Free the actual string buffer */
63
64		if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
65
66			/* But only if it is NOT a pointer into an ACPI table */
67
68			obj_pointer = object->string.pointer;
69		}
70		break;
71
72	case ACPI_TYPE_BUFFER:
73
74		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
75				  "**** Buffer %p, ptr %p\n", object,
76				  object->buffer.pointer));
77
78		/* Free the actual buffer */
79
80		if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
81
82			/* But only if it is NOT a pointer into an ACPI table */
83
84			obj_pointer = object->buffer.pointer;
85		}
86		break;
87
88	case ACPI_TYPE_PACKAGE:
89
90		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
91				  " **** Package of count %X\n",
92				  object->package.count));
93
94		/*
95		 * Elements of the package are not handled here, they are deleted
96		 * separately
97		 */
98
99		/* Free the (variable length) element pointer array */
100
101		obj_pointer = object->package.elements;
102		break;
103
104		/*
105		 * These objects have a possible list of notify handlers.
106		 * Device object also may have a GPE block.
107		 */
108	case ACPI_TYPE_DEVICE:
109
110		if (object->device.gpe_block) {
111			(void)acpi_ev_delete_gpe_block(object->device.
112						       gpe_block);
113		}
114
115		ACPI_FALLTHROUGH;
116
117	case ACPI_TYPE_PROCESSOR:
118	case ACPI_TYPE_THERMAL:
119
120		/* Walk the address handler list for this object */
121
122		handler_desc = object->common_notify.handler;
123		while (handler_desc) {
124			next_desc = handler_desc->address_space.next;
125			acpi_ut_remove_reference(handler_desc);
126			handler_desc = next_desc;
127		}
128		break;
129
130	case ACPI_TYPE_MUTEX:
131
132		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
133				  "***** Mutex %p, OS Mutex %p\n",
134				  object, object->mutex.os_mutex));
135
136		if (object == acpi_gbl_global_lock_mutex) {
137
138			/* Global Lock has extra semaphore */
139
140			(void)
141			    acpi_os_delete_semaphore
142			    (acpi_gbl_global_lock_semaphore);
143			acpi_gbl_global_lock_semaphore = NULL;
144
145			acpi_os_delete_mutex(object->mutex.os_mutex);
146			acpi_gbl_global_lock_mutex = NULL;
147		} else {
148			acpi_ex_unlink_mutex(object);
149			acpi_os_delete_mutex(object->mutex.os_mutex);
150		}
151		break;
152
153	case ACPI_TYPE_EVENT:
154
155		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
156				  "***** Event %p, OS Semaphore %p\n",
157				  object, object->event.os_semaphore));
158
159		(void)acpi_os_delete_semaphore(object->event.os_semaphore);
160		object->event.os_semaphore = NULL;
161		break;
162
163	case ACPI_TYPE_METHOD:
164
165		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
166				  "***** Method %p\n", object));
167
168		/* Delete the method mutex if it exists */
169
170		if (object->method.mutex) {
171			acpi_os_delete_mutex(object->method.mutex->mutex.
172					     os_mutex);
173			acpi_ut_delete_object_desc(object->method.mutex);
174			object->method.mutex = NULL;
175		}
176
177		if (object->method.node) {
178			object->method.node = NULL;
179		}
180		break;
181
182	case ACPI_TYPE_REGION:
183
184		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
185				  "***** Region %p\n", object));
186
187		/*
188		 * Update address_range list. However, only permanent regions
189		 * are installed in this list. (Not created within a method)
190		 */
191		if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
192			acpi_ut_remove_address_range(object->region.space_id,
193						     object->region.node);
194		}
195
196		second_desc = acpi_ns_get_secondary_object(object);
197		if (second_desc) {
198			/*
199			 * Free the region_context if and only if the handler is one of the
200			 * default handlers -- and therefore, we created the context object
201			 * locally, it was not created by an external caller.
202			 */
203			handler_desc = object->region.handler;
204			if (handler_desc) {
205				next_desc =
206				    handler_desc->address_space.region_list;
207				start_desc = next_desc;
208				last_obj_ptr =
209				    &handler_desc->address_space.region_list;
210
211				/* Remove the region object from the handler list */
212
213				while (next_desc) {
214					if (next_desc == object) {
215						*last_obj_ptr =
216						    next_desc->region.next;
217						break;
218					}
219
220					/* Walk the linked list of handlers */
221
222					last_obj_ptr = &next_desc->region.next;
223					next_desc = next_desc->region.next;
224
225					/* Prevent infinite loop if list is corrupted */
226
227					if (next_desc == start_desc) {
228						ACPI_ERROR((AE_INFO,
229							    "Circular region list in address handler object %p",
230							    handler_desc));
231						return_VOID;
232					}
233				}
234
235				if (handler_desc->address_space.handler_flags &
236				    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
237
238					/* Deactivate region and free region context */
239
240					if (handler_desc->address_space.setup) {
241						(void)handler_desc->
242						    address_space.setup(object,
243									ACPI_REGION_DEACTIVATE,
244									handler_desc->
245									address_space.
246									context,
247									&second_desc->
248									extra.
249									region_context);
250					}
251				}
252
253				acpi_ut_remove_reference(handler_desc);
254			}
255
256			/* Now we can free the Extra object */
257
258			acpi_ut_delete_object_desc(second_desc);
259		}
260		if (object->field.internal_pcc_buffer) {
261			ACPI_FREE(object->field.internal_pcc_buffer);
262		}
263
264		break;
265
266	case ACPI_TYPE_BUFFER_FIELD:
267
268		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
269				  "***** Buffer Field %p\n", object));
270
271		second_desc = acpi_ns_get_secondary_object(object);
272		if (second_desc) {
273			acpi_ut_delete_object_desc(second_desc);
274		}
275		break;
276
277	case ACPI_TYPE_LOCAL_BANK_FIELD:
278
279		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
280				  "***** Bank Field %p\n", object));
281
282		second_desc = acpi_ns_get_secondary_object(object);
283		if (second_desc) {
284			acpi_ut_delete_object_desc(second_desc);
285		}
286		break;
287
288	case ACPI_TYPE_LOCAL_ADDRESS_HANDLER:
289
290		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
291				  "***** Address handler %p\n", object));
292
293		acpi_os_delete_mutex(object->address_space.context_mutex);
294		break;
295
296	default:
297
298		break;
299	}
300
301	/* Free any allocated memory (pointer within the object) found above */
302
303	if (obj_pointer) {
304		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
305				  "Deleting Object Subptr %p\n", obj_pointer));
306		ACPI_FREE(obj_pointer);
307	}
308
309	/* Now the object can be safely deleted */
310
311	ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
312			      "%s: Deleting Object %p [%s]\n",
313			      ACPI_GET_FUNCTION_NAME, object,
314			      acpi_ut_get_object_type_name(object)));
315
316	acpi_ut_delete_object_desc(object);
317	return_VOID;
318}
319
320/*******************************************************************************
321 *
322 * FUNCTION:    acpi_ut_delete_internal_object_list
323 *
324 * PARAMETERS:  obj_list        - Pointer to the list to be deleted
325 *
326 * RETURN:      None
327 *
328 * DESCRIPTION: This function deletes an internal object list, including both
329 *              simple objects and package objects
330 *
331 ******************************************************************************/
332
333void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
334{
335	union acpi_operand_object **internal_obj;
336
337	ACPI_FUNCTION_ENTRY();
338
339	/* Walk the null-terminated internal list */
340
341	for (internal_obj = obj_list; *internal_obj; internal_obj++) {
342		acpi_ut_remove_reference(*internal_obj);
343	}
344
345	/* Free the combined parameter pointer list and object array */
346
347	ACPI_FREE(obj_list);
348	return;
349}
350
351/*******************************************************************************
352 *
353 * FUNCTION:    acpi_ut_update_ref_count
354 *
355 * PARAMETERS:  object          - Object whose ref count is to be updated
356 *              action          - What to do (REF_INCREMENT or REF_DECREMENT)
357 *
358 * RETURN:      None. Sets new reference count within the object
359 *
360 * DESCRIPTION: Modify the reference count for an internal acpi object
361 *
362 ******************************************************************************/
363
364static void
365acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
366{
367	u16 original_count;
368	u16 new_count = 0;
369	acpi_cpu_flags lock_flags;
370	char *message;
371
372	ACPI_FUNCTION_NAME(ut_update_ref_count);
373
374	if (!object) {
375		return;
376	}
377
378	/*
379	 * Always get the reference count lock. Note: Interpreter and/or
380	 * Namespace is not always locked when this function is called.
381	 */
382	lock_flags = acpi_os_acquire_lock(acpi_gbl_reference_count_lock);
383	original_count = object->common.reference_count;
384
385	/* Perform the reference count action (increment, decrement) */
386
387	switch (action) {
388	case REF_INCREMENT:
389
390		new_count = original_count + 1;
391		object->common.reference_count = new_count;
392		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
393
394		/* The current reference count should never be zero here */
395
396		if (!original_count) {
397			ACPI_WARNING((AE_INFO,
398				      "Obj %p, Reference Count was zero before increment\n",
399				      object));
400		}
401
402		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
403				  "Obj %p Type %.2X [%s] Refs %.2X [Incremented]\n",
404				  object, object->common.type,
405				  acpi_ut_get_object_type_name(object),
406				  new_count));
407		message = "Incremement";
408		break;
409
410	case REF_DECREMENT:
411
412		/* The current reference count must be non-zero */
413
414		if (original_count) {
415			new_count = original_count - 1;
416			object->common.reference_count = new_count;
417		}
418
419		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
420
421		if (!original_count) {
422			ACPI_WARNING((AE_INFO,
423				      "Obj %p, Reference Count is already zero, cannot decrement\n",
424				      object));
425			return;
426		}
427
428		ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
429				      "%s: Obj %p Type %.2X Refs %.2X [Decremented]\n",
430				      ACPI_GET_FUNCTION_NAME, object,
431				      object->common.type, new_count));
432
433		/* Actually delete the object on a reference count of zero */
434
435		if (new_count == 0) {
436			acpi_ut_delete_internal_obj(object);
437		}
438		message = "Decrement";
439		break;
440
441	default:
442
443		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
444		ACPI_ERROR((AE_INFO, "Unknown Reference Count action (0x%X)",
445			    action));
446		return;
447	}
448
449	/*
450	 * Sanity check the reference count, for debug purposes only.
451	 * (A deleted object will have a huge reference count)
452	 */
453	if (new_count > ACPI_MAX_REFERENCE_COUNT) {
454		ACPI_WARNING((AE_INFO,
455			      "Large Reference Count (0x%X) in object %p, Type=0x%.2X Operation=%s",
456			      new_count, object, object->common.type, message));
457	}
458}
459
460/*******************************************************************************
461 *
462 * FUNCTION:    acpi_ut_update_object_reference
463 *
464 * PARAMETERS:  object              - Increment or decrement the ref count for
465 *                                    this object and all sub-objects
466 *              action              - Either REF_INCREMENT or REF_DECREMENT
467 *
468 * RETURN:      Status
469 *
470 * DESCRIPTION: Increment or decrement the object reference count
471 *
472 * Object references are incremented when:
473 * 1) An object is attached to a Node (namespace object)
474 * 2) An object is copied (all subobjects must be incremented)
475 *
476 * Object references are decremented when:
477 * 1) An object is detached from an Node
478 *
479 ******************************************************************************/
480
481acpi_status
482acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
483{
484	acpi_status status = AE_OK;
485	union acpi_generic_state *state_list = NULL;
486	union acpi_operand_object *next_object = NULL;
487	union acpi_operand_object *prev_object;
488	union acpi_generic_state *state;
489	u32 i;
490
491	ACPI_FUNCTION_NAME(ut_update_object_reference);
492
493	while (object) {
494
495		/* Make sure that this isn't a namespace handle */
496
497		if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
498			ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
499					  "Object %p is NS handle\n", object));
500			return (AE_OK);
501		}
502
503		/*
504		 * All sub-objects must have their reference count updated
505		 * also. Different object types have different subobjects.
506		 */
507		switch (object->common.type) {
508		case ACPI_TYPE_DEVICE:
509		case ACPI_TYPE_PROCESSOR:
510		case ACPI_TYPE_POWER:
511		case ACPI_TYPE_THERMAL:
512			/*
513			 * Update the notify objects for these types (if present)
514			 * Two lists, system and device notify handlers.
515			 */
516			for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
517				prev_object =
518				    object->common_notify.notify_list[i];
519				while (prev_object) {
520					next_object =
521					    prev_object->notify.next[i];
522					acpi_ut_update_ref_count(prev_object,
523								 action);
524					prev_object = next_object;
525				}
526			}
527			break;
528
529		case ACPI_TYPE_PACKAGE:
530			/*
531			 * We must update all the sub-objects of the package,
532			 * each of whom may have their own sub-objects.
533			 */
534			for (i = 0; i < object->package.count; i++) {
535				/*
536				 * Null package elements are legal and can be simply
537				 * ignored.
538				 */
539				next_object = object->package.elements[i];
540				if (!next_object) {
541					continue;
542				}
543
544				switch (next_object->common.type) {
545				case ACPI_TYPE_INTEGER:
546				case ACPI_TYPE_STRING:
547				case ACPI_TYPE_BUFFER:
548					/*
549					 * For these very simple sub-objects, we can just
550					 * update the reference count here and continue.
551					 * Greatly increases performance of this operation.
552					 */
553					acpi_ut_update_ref_count(next_object,
554								 action);
555					break;
556
557				default:
558					/*
559					 * For complex sub-objects, push them onto the stack
560					 * for later processing (this eliminates recursion.)
561					 */
562					status =
563					    acpi_ut_create_update_state_and_push
564					    (next_object, action, &state_list);
565					if (ACPI_FAILURE(status)) {
566						goto error_exit;
567					}
568					break;
569				}
570			}
571
572			next_object = NULL;
573			break;
574
575		case ACPI_TYPE_BUFFER_FIELD:
576
577			next_object = object->buffer_field.buffer_obj;
578			break;
579
580		case ACPI_TYPE_LOCAL_BANK_FIELD:
581
582			next_object = object->bank_field.bank_obj;
583			status =
584			    acpi_ut_create_update_state_and_push(object->
585								 bank_field.
586								 region_obj,
587								 action,
588								 &state_list);
589			if (ACPI_FAILURE(status)) {
590				goto error_exit;
591			}
592			break;
593
594		case ACPI_TYPE_LOCAL_INDEX_FIELD:
595
596			next_object = object->index_field.index_obj;
597			status =
598			    acpi_ut_create_update_state_and_push(object->
599								 index_field.
600								 data_obj,
601								 action,
602								 &state_list);
603			if (ACPI_FAILURE(status)) {
604				goto error_exit;
605			}
606			break;
607
608		case ACPI_TYPE_LOCAL_REFERENCE:
609			/*
610			 * The target of an Index (a package, string, or buffer) or a named
611			 * reference must track changes to the ref count of the index or
612			 * target object.
613			 */
614			if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
615			    (object->reference.class == ACPI_REFCLASS_NAME)) {
616				next_object = object->reference.object;
617			}
618			break;
619
620		case ACPI_TYPE_LOCAL_REGION_FIELD:
621		case ACPI_TYPE_REGION:
622		default:
623
624			break;	/* No subobjects for all other types */
625		}
626
627		/*
628		 * Now we can update the count in the main object. This can only
629		 * happen after we update the sub-objects in case this causes the
630		 * main object to be deleted.
631		 */
632		acpi_ut_update_ref_count(object, action);
633		object = NULL;
634
635		/* Move on to the next object to be updated */
636
637		if (next_object) {
638			object = next_object;
639			next_object = NULL;
640		} else if (state_list) {
641			state = acpi_ut_pop_generic_state(&state_list);
642			object = state->update.object;
643			acpi_ut_delete_generic_state(state);
644		}
645	}
646
647	return (AE_OK);
648
649error_exit:
650
651	ACPI_EXCEPTION((AE_INFO, status,
652			"Could not update object reference count"));
653
654	/* Free any stacked Update State objects */
655
656	while (state_list) {
657		state = acpi_ut_pop_generic_state(&state_list);
658		acpi_ut_delete_generic_state(state);
659	}
660
661	return (status);
662}
663
664/*******************************************************************************
665 *
666 * FUNCTION:    acpi_ut_add_reference
667 *
668 * PARAMETERS:  object          - Object whose reference count is to be
669 *                                incremented
670 *
671 * RETURN:      None
672 *
673 * DESCRIPTION: Add one reference to an ACPI object
674 *
675 ******************************************************************************/
676
677void acpi_ut_add_reference(union acpi_operand_object *object)
678{
679
680	ACPI_FUNCTION_NAME(ut_add_reference);
681
682	/* Ensure that we have a valid object */
683
684	if (!acpi_ut_valid_internal_object(object)) {
685		return;
686	}
687
688	ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
689			  "Obj %p Current Refs=%X [To Be Incremented]\n",
690			  object, object->common.reference_count));
691
692	/* Increment the reference count */
693
694	(void)acpi_ut_update_object_reference(object, REF_INCREMENT);
695	return;
696}
697
698/*******************************************************************************
699 *
700 * FUNCTION:    acpi_ut_remove_reference
701 *
702 * PARAMETERS:  object         - Object whose ref count will be decremented
703 *
704 * RETURN:      None
705 *
706 * DESCRIPTION: Decrement the reference count of an ACPI internal object
707 *
708 ******************************************************************************/
709
710void acpi_ut_remove_reference(union acpi_operand_object *object)
711{
712
713	ACPI_FUNCTION_NAME(ut_remove_reference);
714
715	/*
716	 * Allow a NULL pointer to be passed in, just ignore it. This saves
717	 * each caller from having to check. Also, ignore NS nodes.
718	 */
719	if (!object ||
720	    (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
721		return;
722	}
723
724	/* Ensure that we have a valid object */
725
726	if (!acpi_ut_valid_internal_object(object)) {
727		return;
728	}
729
730	ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
731			      "%s: Obj %p Current Refs=%X [To Be Decremented]\n",
732			      ACPI_GET_FUNCTION_NAME, object,
733			      object->common.reference_count));
734
735	/*
736	 * Decrement the reference count, and only actually delete the object
737	 * if the reference count becomes 0. (Must also decrement the ref count
738	 * of all subobjects!)
739	 */
740	(void)acpi_ut_update_object_reference(object, REF_DECREMENT);
741	return;
742}
743