xref: /openbmc/linux/drivers/acpi/acpica/utdelete.c (revision cd238eff)
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
15 ACPI_MODULE_NAME("utdelete")
16 
17 /* Local prototypes */
18 static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);
19 
20 static void
21 acpi_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 
36 static 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 		/*lint -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 	default:
289 
290 		break;
291 	}
292 
293 	/* Free any allocated memory (pointer within the object) found above */
294 
295 	if (obj_pointer) {
296 		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
297 				  "Deleting Object Subptr %p\n", obj_pointer));
298 		ACPI_FREE(obj_pointer);
299 	}
300 
301 	/* Now the object can be safely deleted */
302 
303 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
304 			      "%s: Deleting Object %p [%s]\n",
305 			      ACPI_GET_FUNCTION_NAME, object,
306 			      acpi_ut_get_object_type_name(object)));
307 
308 	acpi_ut_delete_object_desc(object);
309 	return_VOID;
310 }
311 
312 /*******************************************************************************
313  *
314  * FUNCTION:    acpi_ut_delete_internal_object_list
315  *
316  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
317  *
318  * RETURN:      None
319  *
320  * DESCRIPTION: This function deletes an internal object list, including both
321  *              simple objects and package objects
322  *
323  ******************************************************************************/
324 
325 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
326 {
327 	union acpi_operand_object **internal_obj;
328 
329 	ACPI_FUNCTION_ENTRY();
330 
331 	/* Walk the null-terminated internal list */
332 
333 	for (internal_obj = obj_list; *internal_obj; internal_obj++) {
334 		acpi_ut_remove_reference(*internal_obj);
335 	}
336 
337 	/* Free the combined parameter pointer list and object array */
338 
339 	ACPI_FREE(obj_list);
340 	return;
341 }
342 
343 /*******************************************************************************
344  *
345  * FUNCTION:    acpi_ut_update_ref_count
346  *
347  * PARAMETERS:  object          - Object whose ref count is to be updated
348  *              action          - What to do (REF_INCREMENT or REF_DECREMENT)
349  *
350  * RETURN:      None. Sets new reference count within the object
351  *
352  * DESCRIPTION: Modify the reference count for an internal acpi object
353  *
354  ******************************************************************************/
355 
356 static void
357 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
358 {
359 	u16 original_count;
360 	u16 new_count = 0;
361 	acpi_cpu_flags lock_flags;
362 	char *message;
363 
364 	ACPI_FUNCTION_NAME(ut_update_ref_count);
365 
366 	if (!object) {
367 		return;
368 	}
369 
370 	/*
371 	 * Always get the reference count lock. Note: Interpreter and/or
372 	 * Namespace is not always locked when this function is called.
373 	 */
374 	lock_flags = acpi_os_acquire_lock(acpi_gbl_reference_count_lock);
375 	original_count = object->common.reference_count;
376 
377 	/* Perform the reference count action (increment, decrement) */
378 
379 	switch (action) {
380 	case REF_INCREMENT:
381 
382 		new_count = original_count + 1;
383 		object->common.reference_count = new_count;
384 		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
385 
386 		/* The current reference count should never be zero here */
387 
388 		if (!original_count) {
389 			ACPI_WARNING((AE_INFO,
390 				      "Obj %p, Reference Count was zero before increment\n",
391 				      object));
392 		}
393 
394 		ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
395 				  "Obj %p Type %.2X [%s] Refs %.2X [Incremented]\n",
396 				  object, object->common.type,
397 				  acpi_ut_get_object_type_name(object),
398 				  new_count));
399 		message = "Incremement";
400 		break;
401 
402 	case REF_DECREMENT:
403 
404 		/* The current reference count must be non-zero */
405 
406 		if (original_count) {
407 			new_count = original_count - 1;
408 			object->common.reference_count = new_count;
409 		}
410 
411 		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
412 
413 		if (!original_count) {
414 			ACPI_WARNING((AE_INFO,
415 				      "Obj %p, Reference Count is already zero, cannot decrement\n",
416 				      object));
417 		}
418 
419 		ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
420 				      "%s: Obj %p Type %.2X Refs %.2X [Decremented]\n",
421 				      ACPI_GET_FUNCTION_NAME, object,
422 				      object->common.type, new_count));
423 
424 		/* Actually delete the object on a reference count of zero */
425 
426 		if (new_count == 0) {
427 			acpi_ut_delete_internal_obj(object);
428 		}
429 		message = "Decrement";
430 		break;
431 
432 	default:
433 
434 		acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
435 		ACPI_ERROR((AE_INFO, "Unknown Reference Count action (0x%X)",
436 			    action));
437 		return;
438 	}
439 
440 	/*
441 	 * Sanity check the reference count, for debug purposes only.
442 	 * (A deleted object will have a huge reference count)
443 	 */
444 	if (new_count > ACPI_MAX_REFERENCE_COUNT) {
445 		ACPI_WARNING((AE_INFO,
446 			      "Large Reference Count (0x%X) in object %p, Type=0x%.2X Operation=%s",
447 			      new_count, object, object->common.type, message));
448 	}
449 }
450 
451 /*******************************************************************************
452  *
453  * FUNCTION:    acpi_ut_update_object_reference
454  *
455  * PARAMETERS:  object              - Increment ref count for this object
456  *                                    and all sub-objects
457  *              action              - Either REF_INCREMENT or REF_DECREMENT
458  *
459  * RETURN:      Status
460  *
461  * DESCRIPTION: Increment the object reference count
462  *
463  * Object references are incremented when:
464  * 1) An object is attached to a Node (namespace object)
465  * 2) An object is copied (all subobjects must be incremented)
466  *
467  * Object references are decremented when:
468  * 1) An object is detached from an Node
469  *
470  ******************************************************************************/
471 
472 acpi_status
473 acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
474 {
475 	acpi_status status = AE_OK;
476 	union acpi_generic_state *state_list = NULL;
477 	union acpi_operand_object *next_object = NULL;
478 	union acpi_operand_object *prev_object;
479 	union acpi_generic_state *state;
480 	u32 i;
481 
482 	ACPI_FUNCTION_NAME(ut_update_object_reference);
483 
484 	while (object) {
485 
486 		/* Make sure that this isn't a namespace handle */
487 
488 		if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
489 			ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
490 					  "Object %p is NS handle\n", object));
491 			return (AE_OK);
492 		}
493 
494 		/*
495 		 * All sub-objects must have their reference count incremented
496 		 * also. Different object types have different subobjects.
497 		 */
498 		switch (object->common.type) {
499 		case ACPI_TYPE_DEVICE:
500 		case ACPI_TYPE_PROCESSOR:
501 		case ACPI_TYPE_POWER:
502 		case ACPI_TYPE_THERMAL:
503 			/*
504 			 * Update the notify objects for these types (if present)
505 			 * Two lists, system and device notify handlers.
506 			 */
507 			for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
508 				prev_object =
509 				    object->common_notify.notify_list[i];
510 				while (prev_object) {
511 					next_object =
512 					    prev_object->notify.next[i];
513 					acpi_ut_update_ref_count(prev_object,
514 								 action);
515 					prev_object = next_object;
516 				}
517 			}
518 			break;
519 
520 		case ACPI_TYPE_PACKAGE:
521 			/*
522 			 * We must update all the sub-objects of the package,
523 			 * each of whom may have their own sub-objects.
524 			 */
525 			for (i = 0; i < object->package.count; i++) {
526 				/*
527 				 * Null package elements are legal and can be simply
528 				 * ignored.
529 				 */
530 				next_object = object->package.elements[i];
531 				if (!next_object) {
532 					continue;
533 				}
534 
535 				switch (next_object->common.type) {
536 				case ACPI_TYPE_INTEGER:
537 				case ACPI_TYPE_STRING:
538 				case ACPI_TYPE_BUFFER:
539 					/*
540 					 * For these very simple sub-objects, we can just
541 					 * update the reference count here and continue.
542 					 * Greatly increases performance of this operation.
543 					 */
544 					acpi_ut_update_ref_count(next_object,
545 								 action);
546 					break;
547 
548 				default:
549 					/*
550 					 * For complex sub-objects, push them onto the stack
551 					 * for later processing (this eliminates recursion.)
552 					 */
553 					status =
554 					    acpi_ut_create_update_state_and_push
555 					    (next_object, action, &state_list);
556 					if (ACPI_FAILURE(status)) {
557 						goto error_exit;
558 					}
559 					break;
560 				}
561 			}
562 			next_object = NULL;
563 			break;
564 
565 		case ACPI_TYPE_BUFFER_FIELD:
566 
567 			next_object = object->buffer_field.buffer_obj;
568 			break;
569 
570 		case ACPI_TYPE_LOCAL_REGION_FIELD:
571 
572 			next_object = object->field.region_obj;
573 			break;
574 
575 		case ACPI_TYPE_LOCAL_BANK_FIELD:
576 
577 			next_object = object->bank_field.bank_obj;
578 			status =
579 			    acpi_ut_create_update_state_and_push(object->
580 								 bank_field.
581 								 region_obj,
582 								 action,
583 								 &state_list);
584 			if (ACPI_FAILURE(status)) {
585 				goto error_exit;
586 			}
587 			break;
588 
589 		case ACPI_TYPE_LOCAL_INDEX_FIELD:
590 
591 			next_object = object->index_field.index_obj;
592 			status =
593 			    acpi_ut_create_update_state_and_push(object->
594 								 index_field.
595 								 data_obj,
596 								 action,
597 								 &state_list);
598 			if (ACPI_FAILURE(status)) {
599 				goto error_exit;
600 			}
601 			break;
602 
603 		case ACPI_TYPE_LOCAL_REFERENCE:
604 			/*
605 			 * The target of an Index (a package, string, or buffer) or a named
606 			 * reference must track changes to the ref count of the index or
607 			 * target object.
608 			 */
609 			if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
610 			    (object->reference.class == ACPI_REFCLASS_NAME)) {
611 				next_object = object->reference.object;
612 			}
613 			break;
614 
615 		case ACPI_TYPE_REGION:
616 		default:
617 
618 			break;	/* No subobjects for all other types */
619 		}
620 
621 		/*
622 		 * Now we can update the count in the main object. This can only
623 		 * happen after we update the sub-objects in case this causes the
624 		 * main object to be deleted.
625 		 */
626 		acpi_ut_update_ref_count(object, action);
627 		object = NULL;
628 
629 		/* Move on to the next object to be updated */
630 
631 		if (next_object) {
632 			object = next_object;
633 			next_object = NULL;
634 		} else if (state_list) {
635 			state = acpi_ut_pop_generic_state(&state_list);
636 			object = state->update.object;
637 			acpi_ut_delete_generic_state(state);
638 		}
639 	}
640 
641 	return (AE_OK);
642 
643 error_exit:
644 
645 	ACPI_EXCEPTION((AE_INFO, status,
646 			"Could not update object reference count"));
647 
648 	/* Free any stacked Update State objects */
649 
650 	while (state_list) {
651 		state = acpi_ut_pop_generic_state(&state_list);
652 		acpi_ut_delete_generic_state(state);
653 	}
654 
655 	return (status);
656 }
657 
658 /*******************************************************************************
659  *
660  * FUNCTION:    acpi_ut_add_reference
661  *
662  * PARAMETERS:  object          - Object whose reference count is to be
663  *                                incremented
664  *
665  * RETURN:      None
666  *
667  * DESCRIPTION: Add one reference to an ACPI object
668  *
669  ******************************************************************************/
670 
671 void acpi_ut_add_reference(union acpi_operand_object *object)
672 {
673 
674 	ACPI_FUNCTION_NAME(ut_add_reference);
675 
676 	/* Ensure that we have a valid object */
677 
678 	if (!acpi_ut_valid_internal_object(object)) {
679 		return;
680 	}
681 
682 	ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
683 			  "Obj %p Current Refs=%X [To Be Incremented]\n",
684 			  object, object->common.reference_count));
685 
686 	/* Increment the reference count */
687 
688 	(void)acpi_ut_update_object_reference(object, REF_INCREMENT);
689 	return;
690 }
691 
692 /*******************************************************************************
693  *
694  * FUNCTION:    acpi_ut_remove_reference
695  *
696  * PARAMETERS:  object         - Object whose ref count will be decremented
697  *
698  * RETURN:      None
699  *
700  * DESCRIPTION: Decrement the reference count of an ACPI internal object
701  *
702  ******************************************************************************/
703 
704 void acpi_ut_remove_reference(union acpi_operand_object *object)
705 {
706 
707 	ACPI_FUNCTION_NAME(ut_remove_reference);
708 
709 	/*
710 	 * Allow a NULL pointer to be passed in, just ignore it. This saves
711 	 * each caller from having to check. Also, ignore NS nodes.
712 	 */
713 	if (!object ||
714 	    (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
715 		return;
716 	}
717 
718 	/* Ensure that we have a valid object */
719 
720 	if (!acpi_ut_valid_internal_object(object)) {
721 		return;
722 	}
723 
724 	ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
725 			      "%s: Obj %p Current Refs=%X [To Be Decremented]\n",
726 			      ACPI_GET_FUNCTION_NAME, object,
727 			      object->common.reference_count));
728 
729 	/*
730 	 * Decrement the reference count, and only actually delete the object
731 	 * if the reference count becomes 0. (Must also decrement the ref count
732 	 * of all subobjects!)
733 	 */
734 	(void)acpi_ut_update_object_reference(object, REF_DECREMENT);
735 	return;
736 }
737