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 - 2018, 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 *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
 213                 if (object->method.node) {
 214                         object->method.node = NULL;
 215                 }
 216                 break;
 217
 218         case ACPI_TYPE_REGION:
 219
 220                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 221                                   "***** Region %p\n", object));
 222
 223                 /*
 224                  * Update address_range list. However, only permanent regions
 225                  * are installed in this list. (Not created within a method)
 226                  */
 227                 if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
 228                         acpi_ut_remove_address_range(object->region.space_id,
 229                                                      object->region.node);
 230                 }
 231
 232                 second_desc = acpi_ns_get_secondary_object(object);
 233                 if (second_desc) {
 234                         /*
 235                          * Free the region_context if and only if the handler is one of the
 236                          * default handlers -- and therefore, we created the context object
 237                          * locally, it was not created by an external caller.
 238                          */
 239                         handler_desc = object->region.handler;
 240                         if (handler_desc) {
 241                                 next_desc =
 242                                     handler_desc->address_space.region_list;
 243                                 start_desc = next_desc;
 244                                 last_obj_ptr =
 245                                     &handler_desc->address_space.region_list;
 246
 247                                 /* Remove the region object from the handler list */
 248
 249                                 while (next_desc) {
 250                                         if (next_desc == object) {
 251                                                 *last_obj_ptr =
 252                                                     next_desc->region.next;
 253                                                 break;
 254                                         }
 255
 256                                         /* Walk the linked list of handlers */
 257
 258                                         last_obj_ptr = &next_desc->region.next;
 259                                         next_desc = next_desc->region.next;
 260
 261                                         /* Prevent infinite loop if list is corrupted */
 262
 263                                         if (next_desc == start_desc) {
 264                                                 ACPI_ERROR((AE_INFO,
 265                                                             "Circular region list in address handler object %p",
 266                                                             handler_desc));
 267                                                 return_VOID;
 268                                         }
 269                                 }
 270
 271                                 if (handler_desc->address_space.handler_flags &
 272                                     ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
 273
 274                                         /* Deactivate region and free region context */
 275
 276                                         if (handler_desc->address_space.setup) {
 277                                                 (void)handler_desc->
 278                                                     address_space.setup(object,
 279                                                                         ACPI_REGION_DEACTIVATE,
 280                                                                         handler_desc->
 281                                                                         address_space.
 282                                                                         context,
 283                                                                         &second_desc->
 284                                                                         extra.
 285                                                                         region_context);
 286                                         }
 287                                 }
 288
 289                                 acpi_ut_remove_reference(handler_desc);
 290                         }
 291
 292                         /* Now we can free the Extra object */
 293
 294                         acpi_ut_delete_object_desc(second_desc);
 295                 }
 296                 break;
 297
 298         case ACPI_TYPE_BUFFER_FIELD:
 299
 300                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 301                                   "***** Buffer Field %p\n", object));
 302
 303                 second_desc = acpi_ns_get_secondary_object(object);
 304                 if (second_desc) {
 305                         acpi_ut_delete_object_desc(second_desc);
 306                 }
 307                 break;
 308
 309         case ACPI_TYPE_LOCAL_BANK_FIELD:
 310
 311                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 312                                   "***** Bank Field %p\n", object));
 313
 314                 second_desc = acpi_ns_get_secondary_object(object);
 315                 if (second_desc) {
 316                         acpi_ut_delete_object_desc(second_desc);
 317                 }
 318                 break;
 319
 320         default:
 321
 322                 break;
 323         }
 324
 325         /* Free any allocated memory (pointer within the object) found above */
 326
 327         if (obj_pointer) {
 328                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 329                                   "Deleting Object Subptr %p\n", obj_pointer));
 330                 ACPI_FREE(obj_pointer);
 331         }
 332
 333         /* Now the object can be safely deleted */
 334
 335         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
 336                           object, acpi_ut_get_object_type_name(object)));
 337
 338         acpi_ut_delete_object_desc(object);
 339         return_VOID;
 340 }
 341
 342 /*******************************************************************************
 343  *
 344  * FUNCTION:    acpi_ut_delete_internal_object_list
 345  *
 346  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 347  *
 348  * RETURN:      None
 349  *
 350  * DESCRIPTION: This function deletes an internal object list, including both
 351  *              simple objects and package objects
 352  *
 353  ******************************************************************************/
 354
 355 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
 356 {
 357         union acpi_operand_object **internal_obj;
 358
 359         ACPI_FUNCTION_ENTRY();
 360
 361         /* Walk the null-terminated internal list */
 362
 363         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
 364                 acpi_ut_remove_reference(*internal_obj);
 365         }
 366
 367         /* Free the combined parameter pointer list and object array */
 368
 369         ACPI_FREE(obj_list);
 370         return;
 371 }
 372
 373 /*******************************************************************************
 374  *
 375  * FUNCTION:    acpi_ut_update_ref_count
 376  *
 377  * PARAMETERS:  object          - Object whose ref count is to be updated
 378  *              action          - What to do (REF_INCREMENT or REF_DECREMENT)
 379  *
 380  * RETURN:      None. Sets new reference count within the object
 381  *
 382  * DESCRIPTION: Modify the reference count for an internal acpi object
 383  *
 384  ******************************************************************************/
 385
 386 static void
 387 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
 388 {
 389         u16 original_count;
 390         u16 new_count = 0;
 391         acpi_cpu_flags lock_flags;
 392
 393         ACPI_FUNCTION_NAME(ut_update_ref_count);
 394
 395         if (!object) {
 396                 return;
 397         }
 398
 399         /*
 400          * Always get the reference count lock. Note: Interpreter and/or
 401          * Namespace is not always locked when this function is called.
 402          */
 403         lock_flags = acpi_os_acquire_lock(acpi_gbl_reference_count_lock);
 404         original_count = object->common.reference_count;
 405
 406         /* Perform the reference count action (increment, decrement) */
 407
 408         switch (action) {
 409         case REF_INCREMENT:
 410
 411                 new_count = original_count + 1;
 412                 object->common.reference_count = new_count;
 413                 acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
 414
 415                 /* The current reference count should never be zero here */
 416
 417                 if (!original_count) {
 418                         ACPI_WARNING((AE_INFO,
 419                                       "Obj %p, Reference Count was zero before increment\n",
 420                                       object));
 421                 }
 422
 423                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 424                                   "Obj %p Type %.2X [%s] Refs %.2X [Incremented]\n",
 425                                   object, object->common.type,
 426                                   acpi_ut_get_object_type_name(object),
 427                                   new_count));
 428                 break;
 429
 430         case REF_DECREMENT:
 431
 432                 /* The current reference count must be non-zero */
 433
 434                 if (original_count) {
 435                         new_count = original_count - 1;
 436                         object->common.reference_count = new_count;
 437                 }
 438
 439                 acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
 440
 441                 if (!original_count) {
 442                         ACPI_WARNING((AE_INFO,
 443                                       "Obj %p, Reference Count is already zero, cannot decrement\n",
 444                                       object));
 445                 }
 446
 447                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 448                                   "Obj %p Type %.2X Refs %.2X [Decremented]\n",
 449                                   object, object->common.type, new_count));
 450
 451                 /* Actually delete the object on a reference count of zero */
 452
 453                 if (new_count == 0) {
 454                         acpi_ut_delete_internal_obj(object);
 455                 }
 456                 break;
 457
 458         default:
 459
 460                 acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
 461                 ACPI_ERROR((AE_INFO, "Unknown Reference Count action (0x%X)",
 462                             action));
 463                 return;
 464         }
 465
 466         /*
 467          * Sanity check the reference count, for debug purposes only.
 468          * (A deleted object will have a huge reference count)
 469          */
 470         if (new_count > ACPI_MAX_REFERENCE_COUNT) {
 471                 ACPI_WARNING((AE_INFO,
 472                               "Large Reference Count (0x%X) in object %p, Type=0x%.2X",
 473                               new_count, object, object->common.type));
 474         }
 475 }
 476
 477 /*******************************************************************************
 478  *
 479  * FUNCTION:    acpi_ut_update_object_reference
 480  *
 481  * PARAMETERS:  object              - Increment ref count for this object
 482  *                                    and all sub-objects
 483  *              action              - Either REF_INCREMENT or REF_DECREMENT
 484  *
 485  * RETURN:      Status
 486  *
 487  * DESCRIPTION: Increment the object reference count
 488  *
 489  * Object references are incremented when:
 490  * 1) An object is attached to a Node (namespace object)
 491  * 2) An object is copied (all subobjects must be incremented)
 492  *
 493  * Object references are decremented when:
 494  * 1) An object is detached from an Node
 495  *
 496  ******************************************************************************/
 497
 498 acpi_status
 499 acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
 500 {
 501         acpi_status status = AE_OK;
 502         union acpi_generic_state *state_list = NULL;
 503         union acpi_operand_object *next_object = NULL;
 504         union acpi_operand_object *prev_object;
 505         union acpi_generic_state *state;
 506         u32 i;
 507
 508         ACPI_FUNCTION_NAME(ut_update_object_reference);
 509
 510         while (object) {
 511
 512                 /* Make sure that this isn't a namespace handle */
 513
 514                 if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
 515                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 516                                           "Object %p is NS handle\n", object));
 517                         return (AE_OK);
 518                 }
 519
 520                 /*
 521                  * All sub-objects must have their reference count incremented
 522                  * also. Different object types have different subobjects.
 523                  */
 524                 switch (object->common.type) {
 525                 case ACPI_TYPE_DEVICE:
 526                 case ACPI_TYPE_PROCESSOR:
 527                 case ACPI_TYPE_POWER:
 528                 case ACPI_TYPE_THERMAL:
 529                         /*
 530                          * Update the notify objects for these types (if present)
 531                          * Two lists, system and device notify handlers.
 532                          */
 533                         for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 534                                 prev_object =
 535                                     object->common_notify.notify_list[i];
 536                                 while (prev_object) {
 537                                         next_object =
 538                                             prev_object->notify.next[i];
 539                                         acpi_ut_update_ref_count(prev_object,
 540                                                                  action);
 541                                         prev_object = next_object;
 542                                 }
 543                         }
 544                         break;
 545
 546                 case ACPI_TYPE_PACKAGE:
 547                         /*
 548                          * We must update all the sub-objects of the package,
 549                          * each of whom may have their own sub-objects.
 550                          */
 551                         for (i = 0; i < object->package.count; i++) {
 552                                 /*
 553                                  * Null package elements are legal and can be simply
 554                                  * ignored.
 555                                  */
 556                                 next_object = object->package.elements[i];
 557                                 if (!next_object) {
 558                                         continue;
 559                                 }
 560
 561                                 switch (next_object->common.type) {
 562                                 case ACPI_TYPE_INTEGER:
 563                                 case ACPI_TYPE_STRING:
 564                                 case ACPI_TYPE_BUFFER:
 565                                         /*
 566                                          * For these very simple sub-objects, we can just
 567                                          * update the reference count here and continue.
 568                                          * Greatly increases performance of this operation.
 569                                          */
 570                                         acpi_ut_update_ref_count(next_object,
 571                                                                  action);
 572                                         break;
 573
 574                                 default:
 575                                         /*
 576                                          * For complex sub-objects, push them onto the stack
 577                                          * for later processing (this eliminates recursion.)
 578                                          */
 579                                         status =
 580                                             acpi_ut_create_update_state_and_push
 581                                             (next_object, action, &state_list);
 582                                         if (ACPI_FAILURE(status)) {
 583                                                 goto error_exit;
 584                                         }
 585                                         break;
 586                                 }
 587                         }
 588                         next_object = NULL;
 589                         break;
 590
 591                 case ACPI_TYPE_BUFFER_FIELD:
 592
 593                         next_object = object->buffer_field.buffer_obj;
 594                         break;
 595
 596                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 597
 598                         next_object = object->field.region_obj;
 599                         break;
 600
 601                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 602
 603                         next_object = object->bank_field.bank_obj;
 604                         status =
 605                             acpi_ut_create_update_state_and_push(object->
 606                                                                  bank_field.
 607                                                                  region_obj,
 608                                                                  action,
 609                                                                  &state_list);
 610                         if (ACPI_FAILURE(status)) {
 611                                 goto error_exit;
 612                         }
 613                         break;
 614
 615                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
 616
 617                         next_object = object->index_field.index_obj;
 618                         status =
 619                             acpi_ut_create_update_state_and_push(object->
 620                                                                  index_field.
 621                                                                  data_obj,
 622                                                                  action,
 623                                                                  &state_list);
 624                         if (ACPI_FAILURE(status)) {
 625                                 goto error_exit;
 626                         }
 627                         break;
 628
 629                 case ACPI_TYPE_LOCAL_REFERENCE:
 630                         /*
 631                          * The target of an Index (a package, string, or buffer) or a named
 632                          * reference must track changes to the ref count of the index or
 633                          * target object.
 634                          */
 635                         if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
 636                             (object->reference.class == ACPI_REFCLASS_NAME)) {
 637                                 next_object = object->reference.object;
 638                         }
 639                         break;
 640
 641                 case ACPI_TYPE_REGION:
 642                 default:
 643
 644                         break;  /* No subobjects for all other types */
 645                 }
 646
 647                 /*
 648                  * Now we can update the count in the main object. This can only
 649                  * happen after we update the sub-objects in case this causes the
 650                  * main object to be deleted.
 651                  */
 652                 acpi_ut_update_ref_count(object, action);
 653                 object = NULL;
 654
 655                 /* Move on to the next object to be updated */
 656
 657                 if (next_object) {
 658                         object = next_object;
 659                         next_object = NULL;
 660                 } else if (state_list) {
 661                         state = acpi_ut_pop_generic_state(&state_list);
 662                         object = state->update.object;
 663                         acpi_ut_delete_generic_state(state);
 664                 }
 665         }
 666
 667         return (AE_OK);
 668
 669 error_exit:
 670
 671         ACPI_EXCEPTION((AE_INFO, status,
 672                         "Could not update object reference count"));
 673
 674         /* Free any stacked Update State objects */
 675
 676         while (state_list) {
 677                 state = acpi_ut_pop_generic_state(&state_list);
 678                 acpi_ut_delete_generic_state(state);
 679         }
 680
 681         return (status);
 682 }
 683
 684 /*******************************************************************************
 685  *
 686  * FUNCTION:    acpi_ut_add_reference
 687  *
 688  * PARAMETERS:  object          - Object whose reference count is to be
 689  *                                incremented
 690  *
 691  * RETURN:      None
 692  *
 693  * DESCRIPTION: Add one reference to an ACPI object
 694  *
 695  ******************************************************************************/
 696
 697 void acpi_ut_add_reference(union acpi_operand_object *object)
 698 {
 699
 700         ACPI_FUNCTION_NAME(ut_add_reference);
 701
 702         /* Ensure that we have a valid object */
 703
 704         if (!acpi_ut_valid_internal_object(object)) {
 705                 return;
 706         }
 707
 708         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 709                           "Obj %p Current Refs=%X [To Be Incremented]\n",
 710                           object, object->common.reference_count));
 711
 712         /* Increment the reference count */
 713
 714         (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
 715         return;
 716 }
 717
 718 /*******************************************************************************
 719  *
 720  * FUNCTION:    acpi_ut_remove_reference
 721  *
 722  * PARAMETERS:  object         - Object whose ref count will be decremented
 723  *
 724  * RETURN:      None
 725  *
 726  * DESCRIPTION: Decrement the reference count of an ACPI internal object
 727  *
 728  ******************************************************************************/
 729
 730 void acpi_ut_remove_reference(union acpi_operand_object *object)
 731 {
 732
 733         ACPI_FUNCTION_NAME(ut_remove_reference);
 734
 735         /*
 736          * Allow a NULL pointer to be passed in, just ignore it. This saves
 737          * each caller from having to check. Also, ignore NS nodes.
 738          */
 739         if (!object ||
 740             (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
 741                 return;
 742         }
 743
 744         /* Ensure that we have a valid object */
 745
 746         if (!acpi_ut_valid_internal_object(object)) {
 747                 return;
 748         }
 749
 750         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 751                           "Obj %p Current Refs=%X [To Be Decremented]\n",
 752                           object, object->common.reference_count));
 753
 754         /*
 755          * Decrement the reference count, and only actually delete the object
 756          * if the reference count becomes 0. (Must also decrement the ref count
 757          * of all subobjects!)
 758          */
 759         (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
 760         return;
 761 }