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 - 2013, Intel Corp.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "acinterp.h"
  47 #include "acnamesp.h"
  48 #include "acevents.h"
  49
  50 #define _COMPONENT          ACPI_UTILITIES
  51 ACPI_MODULE_NAME("utdelete")
  52
  53 /* Local prototypes */
  54 static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);
  55
  56 static void
  57 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action);
  58
  59 /*******************************************************************************
  60  *
  61  * FUNCTION:    acpi_ut_delete_internal_obj
  62  *
  63  * PARAMETERS:  object         - Object to be deleted
  64  *
  65  * RETURN:      None
  66  *
  67  * DESCRIPTION: Low level object deletion, after reference counts have been
  68  *              updated (All reference counts, including sub-objects!)
  69  *
  70  ******************************************************************************/
  71
  72 static void acpi_ut_delete_internal_obj(union acpi_operand_object *object)
  73 {
  74         void *obj_pointer = NULL;
  75         union acpi_operand_object *handler_desc;
  76         union acpi_operand_object *second_desc;
  77         union acpi_operand_object *next_desc;
  78         union acpi_operand_object **last_obj_ptr;
  79
  80         ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);
  81
  82         if (!object) {
  83                 return_VOID;
  84         }
  85
  86         /*
  87          * Must delete or free any pointers within the object that are not
  88          * actual ACPI objects (for example, a raw buffer pointer).
  89          */
  90         switch (object->common.type) {
  91         case ACPI_TYPE_STRING:
  92
  93                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
  94                                   "**** String %p, ptr %p\n", object,
  95                                   object->string.pointer));
  96
  97                 /* Free the actual string buffer */
  98
  99                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
 100
 101                         /* But only if it is NOT a pointer into an ACPI table */
 102
 103                         obj_pointer = object->string.pointer;
 104                 }
 105                 break;
 106
 107         case ACPI_TYPE_BUFFER:
 108
 109                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 110                                   "**** Buffer %p, ptr %p\n", object,
 111                                   object->buffer.pointer));
 112
 113                 /* Free the actual buffer */
 114
 115                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
 116
 117                         /* But only if it is NOT a pointer into an ACPI table */
 118
 119                         obj_pointer = object->buffer.pointer;
 120                 }
 121                 break;
 122
 123         case ACPI_TYPE_PACKAGE:
 124
 125                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 126                                   " **** Package of count %X\n",
 127                                   object->package.count));
 128
 129                 /*
 130                  * Elements of the package are not handled here, they are deleted
 131                  * separately
 132                  */
 133
 134                 /* Free the (variable length) element pointer array */
 135
 136                 obj_pointer = object->package.elements;
 137                 break;
 138
 139                 /*
 140                  * These objects have a possible list of notify handlers.
 141                  * Device object also may have a GPE block.
 142                  */
 143         case ACPI_TYPE_DEVICE:
 144
 145                 if (object->device.gpe_block) {
 146                         (void)acpi_ev_delete_gpe_block(object->device.
 147                                                        gpe_block);
 148                 }
 149
 150                 /*lint -fallthrough */
 151
 152         case ACPI_TYPE_PROCESSOR:
 153         case ACPI_TYPE_THERMAL:
 154
 155                 /* Walk the address handler list for this object */
 156
 157                 handler_desc = object->common_notify.handler;
 158                 while (handler_desc) {
 159                         next_desc = handler_desc->address_space.next;
 160                         acpi_ut_remove_reference(handler_desc);
 161                         handler_desc = next_desc;
 162                 }
 163                 break;
 164
 165         case ACPI_TYPE_MUTEX:
 166
 167                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 168                                   "***** Mutex %p, OS Mutex %p\n",
 169                                   object, object->mutex.os_mutex));
 170
 171                 if (object == acpi_gbl_global_lock_mutex) {
 172
 173                         /* Global Lock has extra semaphore */
 174
 175                         (void)
 176                             acpi_os_delete_semaphore
 177                             (acpi_gbl_global_lock_semaphore);
 178                         acpi_gbl_global_lock_semaphore = NULL;
 179
 180                         acpi_os_delete_mutex(object->mutex.os_mutex);
 181                         acpi_gbl_global_lock_mutex = NULL;
 182                 } else {
 183                         acpi_ex_unlink_mutex(object);
 184                         acpi_os_delete_mutex(object->mutex.os_mutex);
 185                 }
 186                 break;
 187
 188         case ACPI_TYPE_EVENT:
 189
 190                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 191                                   "***** Event %p, OS Semaphore %p\n",
 192                                   object, object->event.os_semaphore));
 193
 194                 (void)acpi_os_delete_semaphore(object->event.os_semaphore);
 195                 object->event.os_semaphore = NULL;
 196                 break;
 197
 198         case ACPI_TYPE_METHOD:
 199
 200                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 201                                   "***** Method %p\n", object));
 202
 203                 /* Delete the method mutex if it exists */
 204
 205                 if (object->method.mutex) {
 206                         acpi_os_delete_mutex(object->method.mutex->mutex.
 207                                              os_mutex);
 208                         acpi_ut_delete_object_desc(object->method.mutex);
 209                         object->method.mutex = NULL;
 210                 }
 211                 break;
 212
 213         case ACPI_TYPE_REGION:
 214
 215                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 216                                   "***** Region %p\n", object));
 217
 218                 /*
 219                  * Update address_range list. However, only permanent regions
 220                  * are installed in this list. (Not created within a method)
 221                  */
 222                 if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
 223                         acpi_ut_remove_address_range(object->region.space_id,
 224                                                      object->region.node);
 225                 }
 226
 227                 second_desc = acpi_ns_get_secondary_object(object);
 228                 if (second_desc) {
 229                         /*
 230                          * Free the region_context if and only if the handler is one of the
 231                          * default handlers -- and therefore, we created the context object
 232                          * locally, it was not created by an external caller.
 233                          */
 234                         handler_desc = object->region.handler;
 235                         if (handler_desc) {
 236                                 next_desc =
 237                                     handler_desc->address_space.region_list;
 238                                 last_obj_ptr =
 239                                     &handler_desc->address_space.region_list;
 240
 241                                 /* Remove the region object from the handler's list */
 242
 243                                 while (next_desc) {
 244                                         if (next_desc == object) {
 245                                                 *last_obj_ptr =
 246                                                     next_desc->region.next;
 247                                                 break;
 248                                         }
 249
 250                                         /* Walk the linked list of handler */
 251
 252                                         last_obj_ptr = &next_desc->region.next;
 253                                         next_desc = next_desc->region.next;
 254                                 }
 255
 256                                 if (handler_desc->address_space.handler_flags &
 257                                     ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
 258
 259                                         /* Deactivate region and free region context */
 260
 261                                         if (handler_desc->address_space.setup) {
 262                                                 (void)handler_desc->
 263                                                     address_space.setup(object,
 264                                                                         ACPI_REGION_DEACTIVATE,
 265                                                                         handler_desc->
 266                                                                         address_space.
 267                                                                         context,
 268                                                                         &second_desc->
 269                                                                         extra.
 270                                                                         region_context);
 271                                         }
 272                                 }
 273
 274                                 acpi_ut_remove_reference(handler_desc);
 275                         }
 276
 277                         /* Now we can free the Extra object */
 278
 279                         acpi_ut_delete_object_desc(second_desc);
 280                 }
 281                 break;
 282
 283         case ACPI_TYPE_BUFFER_FIELD:
 284
 285                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 286                                   "***** Buffer Field %p\n", object));
 287
 288                 second_desc = acpi_ns_get_secondary_object(object);
 289                 if (second_desc) {
 290                         acpi_ut_delete_object_desc(second_desc);
 291                 }
 292                 break;
 293
 294         case ACPI_TYPE_LOCAL_BANK_FIELD:
 295
 296                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 297                                   "***** Bank Field %p\n", object));
 298
 299                 second_desc = acpi_ns_get_secondary_object(object);
 300                 if (second_desc) {
 301                         acpi_ut_delete_object_desc(second_desc);
 302                 }
 303                 break;
 304
 305         default:
 306                 break;
 307         }
 308
 309         /* Free any allocated memory (pointer within the object) found above */
 310
 311         if (obj_pointer) {
 312                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 313                                   "Deleting Object Subptr %p\n", obj_pointer));
 314                 ACPI_FREE(obj_pointer);
 315         }
 316
 317         /* Now the object can be safely deleted */
 318
 319         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
 320                           object, acpi_ut_get_object_type_name(object)));
 321
 322         acpi_ut_delete_object_desc(object);
 323         return_VOID;
 324 }
 325
 326 /*******************************************************************************
 327  *
 328  * FUNCTION:    acpi_ut_delete_internal_object_list
 329  *
 330  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 331  *
 332  * RETURN:      None
 333  *
 334  * DESCRIPTION: This function deletes an internal object list, including both
 335  *              simple objects and package objects
 336  *
 337  ******************************************************************************/
 338
 339 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
 340 {
 341         union acpi_operand_object **internal_obj;
 342
 343         ACPI_FUNCTION_ENTRY();
 344
 345         /* Walk the null-terminated internal list */
 346
 347         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
 348                 acpi_ut_remove_reference(*internal_obj);
 349         }
 350
 351         /* Free the combined parameter pointer list and object array */
 352
 353         ACPI_FREE(obj_list);
 354         return;
 355 }
 356
 357 /*******************************************************************************
 358  *
 359  * FUNCTION:    acpi_ut_update_ref_count
 360  *
 361  * PARAMETERS:  object          - Object whose ref count is to be updated
 362  *              action          - What to do
 363  *
 364  * RETURN:      New ref count
 365  *
 366  * DESCRIPTION: Modify the ref count and return it.
 367  *
 368  ******************************************************************************/
 369
 370 static void
 371 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
 372 {
 373         u16 count;
 374         u16 new_count;
 375
 376         ACPI_FUNCTION_NAME(ut_update_ref_count);
 377
 378         if (!object) {
 379                 return;
 380         }
 381
 382         count = object->common.reference_count;
 383         new_count = count;
 384
 385         /*
 386          * Perform the reference count action (increment, decrement, force delete)
 387          */
 388         switch (action) {
 389         case REF_INCREMENT:
 390
 391                 new_count++;
 392                 object->common.reference_count = new_count;
 393
 394                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 395                                   "Obj %p Refs=%X, [Incremented]\n",
 396                                   object, new_count));
 397                 break;
 398
 399         case REF_DECREMENT:
 400
 401                 if (count < 1) {
 402                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 403                                           "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
 404                                           object, new_count));
 405
 406                         new_count = 0;
 407                 } else {
 408                         new_count--;
 409
 410                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 411                                           "Obj %p Refs=%X, [Decremented]\n",
 412                                           object, new_count));
 413                 }
 414
 415                 if (object->common.type == ACPI_TYPE_METHOD) {
 416                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 417                                           "Method Obj %p Refs=%X, [Decremented]\n",
 418                                           object, new_count));
 419                 }
 420
 421                 object->common.reference_count = new_count;
 422                 if (new_count == 0) {
 423                         acpi_ut_delete_internal_obj(object);
 424                 }
 425                 break;
 426
 427         case REF_FORCE_DELETE:
 428
 429                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 430                                   "Obj %p Refs=%X, Force delete! (Set to 0)\n",
 431                                   object, count));
 432
 433                 new_count = 0;
 434                 object->common.reference_count = new_count;
 435                 acpi_ut_delete_internal_obj(object);
 436                 break;
 437
 438         default:
 439
 440                 ACPI_ERROR((AE_INFO, "Unknown action (0x%X)", action));
 441                 break;
 442         }
 443
 444         /*
 445          * Sanity check the reference count, for debug purposes only.
 446          * (A deleted object will have a huge reference count)
 447          */
 448         if (count > ACPI_MAX_REFERENCE_COUNT) {
 449                 ACPI_WARNING((AE_INFO,
 450                               "Large Reference Count (0x%X) in object %p",
 451                               count, object));
 452         }
 453 }
 454
 455 /*******************************************************************************
 456  *
 457  * FUNCTION:    acpi_ut_update_object_reference
 458  *
 459  * PARAMETERS:  object              - Increment ref count for this object
 460  *                                    and all sub-objects
 461  *              action              - Either REF_INCREMENT or REF_DECREMENT or
 462  *                                    REF_FORCE_DELETE
 463  *
 464  * RETURN:      Status
 465  *
 466  * DESCRIPTION: Increment the object reference count
 467  *
 468  * Object references are incremented when:
 469  * 1) An object is attached to a Node (namespace object)
 470  * 2) An object is copied (all subobjects must be incremented)
 471  *
 472  * Object references are decremented when:
 473  * 1) An object is detached from an Node
 474  *
 475  ******************************************************************************/
 476
 477 acpi_status
 478 acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
 479 {
 480         acpi_status status = AE_OK;
 481         union acpi_generic_state *state_list = NULL;
 482         union acpi_operand_object *next_object = NULL;
 483         union acpi_operand_object *prev_object;
 484         union acpi_generic_state *state;
 485         u32 i;
 486
 487         ACPI_FUNCTION_NAME(ut_update_object_reference);
 488
 489         while (object) {
 490
 491                 /* Make sure that this isn't a namespace handle */
 492
 493                 if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
 494                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 495                                           "Object %p is NS handle\n", object));
 496                         return (AE_OK);
 497                 }
 498
 499                 /*
 500                  * All sub-objects must have their reference count incremented also.
 501                  * Different object types have different subobjects.
 502                  */
 503                 switch (object->common.type) {
 504                 case ACPI_TYPE_DEVICE:
 505                 case ACPI_TYPE_PROCESSOR:
 506                 case ACPI_TYPE_POWER:
 507                 case ACPI_TYPE_THERMAL:
 508
 509                         /*
 510                          * Update the notify objects for these types (if present)
 511                          * Two lists, system and device notify handlers.
 512                          */
 513                         for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
 514                                 prev_object =
 515                                     object->common_notify.notify_list[i];
 516                                 while (prev_object) {
 517                                         next_object =
 518                                             prev_object->notify.next[i];
 519                                         acpi_ut_update_ref_count(prev_object,
 520                                                                  action);
 521                                         prev_object = next_object;
 522                                 }
 523                         }
 524                         break;
 525
 526                 case ACPI_TYPE_PACKAGE:
 527                         /*
 528                          * We must update all the sub-objects of the package,
 529                          * each of whom may have their own sub-objects.
 530                          */
 531                         for (i = 0; i < object->package.count; i++) {
 532                                 /*
 533                                  * Null package elements are legal and can be simply
 534                                  * ignored.
 535                                  */
 536                                 next_object = object->package.elements[i];
 537                                 if (!next_object) {
 538                                         continue;
 539                                 }
 540
 541                                 switch (next_object->common.type) {
 542                                 case ACPI_TYPE_INTEGER:
 543                                 case ACPI_TYPE_STRING:
 544                                 case ACPI_TYPE_BUFFER:
 545                                         /*
 546                                          * For these very simple sub-objects, we can just
 547                                          * update the reference count here and continue.
 548                                          * Greatly increases performance of this operation.
 549                                          */
 550                                         acpi_ut_update_ref_count(next_object,
 551                                                                  action);
 552                                         break;
 553
 554                                 default:
 555                                         /*
 556                                          * For complex sub-objects, push them onto the stack
 557                                          * for later processing (this eliminates recursion.)
 558                                          */
 559                                         status =
 560                                             acpi_ut_create_update_state_and_push
 561                                             (next_object, action, &state_list);
 562                                         if (ACPI_FAILURE(status)) {
 563                                                 goto error_exit;
 564                                         }
 565                                         break;
 566                                 }
 567                         }
 568                         next_object = NULL;
 569                         break;
 570
 571                 case ACPI_TYPE_BUFFER_FIELD:
 572
 573                         next_object = object->buffer_field.buffer_obj;
 574                         break;
 575
 576                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 577
 578                         next_object = object->field.region_obj;
 579                         break;
 580
 581                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 582
 583                         next_object = object->bank_field.bank_obj;
 584                         status =
 585                             acpi_ut_create_update_state_and_push(object->
 586                                                                  bank_field.
 587                                                                  region_obj,
 588                                                                  action,
 589                                                                  &state_list);
 590                         if (ACPI_FAILURE(status)) {
 591                                 goto error_exit;
 592                         }
 593                         break;
 594
 595                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
 596
 597                         next_object = object->index_field.index_obj;
 598                         status =
 599                             acpi_ut_create_update_state_and_push(object->
 600                                                                  index_field.
 601                                                                  data_obj,
 602                                                                  action,
 603                                                                  &state_list);
 604                         if (ACPI_FAILURE(status)) {
 605                                 goto error_exit;
 606                         }
 607                         break;
 608
 609                 case ACPI_TYPE_LOCAL_REFERENCE:
 610                         /*
 611                          * The target of an Index (a package, string, or buffer) or a named
 612                          * reference must track changes to the ref count of the index or
 613                          * target object.
 614                          */
 615                         if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
 616                             (object->reference.class == ACPI_REFCLASS_NAME)) {
 617                                 next_object = object->reference.object;
 618                         }
 619                         break;
 620
 621                 case ACPI_TYPE_REGION:
 622                 default:
 623                         break;  /* No subobjects for all other types */
 624                 }
 625
 626                 /*
 627                  * Now we can update the count in the main object. This can only
 628                  * happen after we update the sub-objects in case this causes the
 629                  * main object to be deleted.
 630                  */
 631                 acpi_ut_update_ref_count(object, action);
 632                 object = NULL;
 633
 634                 /* Move on to the next object to be updated */
 635
 636                 if (next_object) {
 637                         object = next_object;
 638                         next_object = NULL;
 639                 } else if (state_list) {
 640                         state = acpi_ut_pop_generic_state(&state_list);
 641                         object = state->update.object;
 642                         acpi_ut_delete_generic_state(state);
 643                 }
 644         }
 645
 646         return (AE_OK);
 647
 648       error_exit:
 649
 650         ACPI_EXCEPTION((AE_INFO, status,
 651                         "Could not update object reference count"));
 652
 653         /* Free any stacked Update State objects */
 654
 655         while (state_list) {
 656                 state = acpi_ut_pop_generic_state(&state_list);
 657                 acpi_ut_delete_generic_state(state);
 658         }
 659
 660         return (status);
 661 }
 662
 663 /*******************************************************************************
 664  *
 665  * FUNCTION:    acpi_ut_add_reference
 666  *
 667  * PARAMETERS:  object          - Object whose reference count is to be
 668  *                                incremented
 669  *
 670  * RETURN:      None
 671  *
 672  * DESCRIPTION: Add one reference to an ACPI object
 673  *
 674  ******************************************************************************/
 675
 676 void acpi_ut_add_reference(union acpi_operand_object *object)
 677 {
 678
 679         ACPI_FUNCTION_NAME(ut_add_reference);
 680
 681         /* Ensure that we have a valid object */
 682
 683         if (!acpi_ut_valid_internal_object(object)) {
 684                 return;
 685         }
 686
 687         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 688                           "Obj %p Current Refs=%X [To Be Incremented]\n",
 689                           object, object->common.reference_count));
 690
 691         /* Increment the reference count */
 692
 693         (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
 694         return;
 695 }
 696
 697 /*******************************************************************************
 698  *
 699  * FUNCTION:    acpi_ut_remove_reference
 700  *
 701  * PARAMETERS:  object         - Object whose ref count will be decremented
 702  *
 703  * RETURN:      None
 704  *
 705  * DESCRIPTION: Decrement the reference count of an ACPI internal object
 706  *
 707  ******************************************************************************/
 708
 709 void acpi_ut_remove_reference(union acpi_operand_object *object)
 710 {
 711
 712         ACPI_FUNCTION_NAME(ut_remove_reference);
 713
 714         /*
 715          * Allow a NULL pointer to be passed in, just ignore it. This saves
 716          * each caller from having to check. Also, ignore NS nodes.
 717          *
 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((ACPI_DB_ALLOCATIONS,
 731                           "Obj %p Current Refs=%X [To Be Decremented]\n",
 732                           object, object->common.reference_count));
 733
 734         /*
 735          * Decrement the reference count, and only actually delete the object
 736          * if the reference count becomes 0. (Must also decrement the ref count
 737          * of all subobjects!)
 738          */
 739         (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
 740         return;
 741 }