drivers/acpi/utilities/utdelete.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: utdelete - object deletion and reference count utilities
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2007, R. Byron Moore
   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 <acpi/acinterp.h>
  46 #include <acpi/acnamesp.h>
  47 #include <acpi/acevents.h>
  48 #include <acpi/amlcode.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
  79         ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);
  80
  81         if (!object) {
  82                 return_VOID;
  83         }
  84
  85         /*
  86          * Must delete or free any pointers within the object that are not
  87          * actual ACPI objects (for example, a raw buffer pointer).
  88          */
  89         switch (ACPI_GET_OBJECT_TYPE(object)) {
  90         case ACPI_TYPE_STRING:
  91
  92                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
  93                                   "**** String %p, ptr %p\n", object,
  94                                   object->string.pointer));
  95
  96                 /* Free the actual string buffer */
  97
  98                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
  99
 100                         /* But only if it is NOT a pointer into an ACPI table */
 101
 102                         obj_pointer = object->string.pointer;
 103                 }
 104                 break;
 105
 106         case ACPI_TYPE_BUFFER:
 107
 108                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 109                                   "**** Buffer %p, ptr %p\n", object,
 110                                   object->buffer.pointer));
 111
 112                 /* Free the actual buffer */
 113
 114                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
 115
 116                         /* But only if it is NOT a pointer into an ACPI table */
 117
 118                         obj_pointer = object->buffer.pointer;
 119                 }
 120                 break;
 121
 122         case ACPI_TYPE_PACKAGE:
 123
 124                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 125                                   " **** Package of count %X\n",
 126                                   object->package.count));
 127
 128                 /*
 129                  * Elements of the package are not handled here, they are deleted
 130                  * separately
 131                  */
 132
 133                 /* Free the (variable length) element pointer array */
 134
 135                 obj_pointer = object->package.elements;
 136                 break;
 137
 138         case ACPI_TYPE_DEVICE:
 139
 140                 if (object->device.gpe_block) {
 141                         (void)acpi_ev_delete_gpe_block(object->device.
 142                                                        gpe_block);
 143                 }
 144
 145                 /* Walk the handler list for this device */
 146
 147                 handler_desc = object->device.handler;
 148                 while (handler_desc) {
 149                         next_desc = handler_desc->address_space.next;
 150                         acpi_ut_remove_reference(handler_desc);
 151                         handler_desc = next_desc;
 152                 }
 153                 break;
 154
 155         case ACPI_TYPE_MUTEX:
 156
 157                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 158                                   "***** Mutex %p, OS Mutex %p\n",
 159                                   object, object->mutex.os_mutex));
 160
 161                 if (object == acpi_gbl_global_lock_mutex) {
 162
 163                         /* Global Lock has extra semaphore */
 164
 165                         (void)
 166                             acpi_os_delete_semaphore
 167                             (acpi_gbl_global_lock_semaphore);
 168                         acpi_gbl_global_lock_semaphore = NULL;
 169
 170                         acpi_os_delete_mutex(object->mutex.os_mutex);
 171                         acpi_gbl_global_lock_mutex = NULL;
 172                 } else {
 173                         acpi_ex_unlink_mutex(object);
 174                         acpi_os_delete_mutex(object->mutex.os_mutex);
 175                 }
 176                 break;
 177
 178         case ACPI_TYPE_EVENT:
 179
 180                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 181                                   "***** Event %p, OS Semaphore %p\n",
 182                                   object, object->event.os_semaphore));
 183
 184                 (void)acpi_os_delete_semaphore(object->event.os_semaphore);
 185                 object->event.os_semaphore = NULL;
 186                 break;
 187
 188         case ACPI_TYPE_METHOD:
 189
 190                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 191                                   "***** Method %p\n", object));
 192
 193                 /* Delete the method mutex if it exists */
 194
 195                 if (object->method.mutex) {
 196                         acpi_os_delete_mutex(object->method.mutex->mutex.
 197                                              os_mutex);
 198                         acpi_ut_delete_object_desc(object->method.mutex);
 199                         object->method.mutex = NULL;
 200                 }
 201                 break;
 202
 203         case ACPI_TYPE_REGION:
 204
 205                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 206                                   "***** Region %p\n", object));
 207
 208                 second_desc = acpi_ns_get_secondary_object(object);
 209                 if (second_desc) {
 210                         /*
 211                          * Free the region_context if and only if the handler is one of the
 212                          * default handlers -- and therefore, we created the context object
 213                          * locally, it was not created by an external caller.
 214                          */
 215                         handler_desc = object->region.handler;
 216                         if (handler_desc) {
 217                                 if (handler_desc->address_space.handler_flags &
 218                                     ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
 219
 220                                         /* Deactivate region and free region context */
 221
 222                                         if (handler_desc->address_space.setup) {
 223                                                 (void)handler_desc->
 224                                                     address_space.setup(object,
 225                                                                         ACPI_REGION_DEACTIVATE,
 226                                                                         handler_desc->
 227                                                                         address_space.
 228                                                                         context,
 229                                                                         &second_desc->
 230                                                                         extra.
 231                                                                         region_context);
 232                                         }
 233                                 }
 234
 235                                 acpi_ut_remove_reference(handler_desc);
 236                         }
 237
 238                         /* Now we can free the Extra object */
 239
 240                         acpi_ut_delete_object_desc(second_desc);
 241                 }
 242                 break;
 243
 244         case ACPI_TYPE_BUFFER_FIELD:
 245
 246                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 247                                   "***** Buffer Field %p\n", object));
 248
 249                 second_desc = acpi_ns_get_secondary_object(object);
 250                 if (second_desc) {
 251                         acpi_ut_delete_object_desc(second_desc);
 252                 }
 253                 break;
 254
 255         case ACPI_TYPE_LOCAL_BANK_FIELD:
 256
 257                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 258                                   "***** Bank Field %p\n", object));
 259
 260                 second_desc = acpi_ns_get_secondary_object(object);
 261                 if (second_desc) {
 262                         acpi_ut_delete_object_desc(second_desc);
 263                 }
 264                 break;
 265
 266         default:
 267                 break;
 268         }
 269
 270         /* Free any allocated memory (pointer within the object) found above */
 271
 272         if (obj_pointer) {
 273                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 274                                   "Deleting Object Subptr %p\n", obj_pointer));
 275                 ACPI_FREE(obj_pointer);
 276         }
 277
 278         /* Now the object can be safely deleted */
 279
 280         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
 281                           object, acpi_ut_get_object_type_name(object)));
 282
 283         acpi_ut_delete_object_desc(object);
 284         return_VOID;
 285 }
 286
 287 /*******************************************************************************
 288  *
 289  * FUNCTION:    acpi_ut_delete_internal_object_list
 290  *
 291  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 292  *
 293  * RETURN:      None
 294  *
 295  * DESCRIPTION: This function deletes an internal object list, including both
 296  *              simple objects and package objects
 297  *
 298  ******************************************************************************/
 299
 300 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
 301 {
 302         union acpi_operand_object **internal_obj;
 303
 304         ACPI_FUNCTION_TRACE(ut_delete_internal_object_list);
 305
 306         /* Walk the null-terminated internal list */
 307
 308         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
 309                 acpi_ut_remove_reference(*internal_obj);
 310         }
 311
 312         /* Free the combined parameter pointer list and object array */
 313
 314         ACPI_FREE(obj_list);
 315         return_VOID;
 316 }
 317
 318 /*******************************************************************************
 319  *
 320  * FUNCTION:    acpi_ut_update_ref_count
 321  *
 322  * PARAMETERS:  Object          - Object whose ref count is to be updated
 323  *              Action          - What to do
 324  *
 325  * RETURN:      New ref count
 326  *
 327  * DESCRIPTION: Modify the ref count and return it.
 328  *
 329  ******************************************************************************/
 330
 331 static void
 332 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
 333 {
 334         u16 count;
 335         u16 new_count;
 336
 337         ACPI_FUNCTION_NAME(ut_update_ref_count);
 338
 339         if (!object) {
 340                 return;
 341         }
 342
 343         count = object->common.reference_count;
 344         new_count = count;
 345
 346         /*
 347          * Perform the reference count action (increment, decrement, force delete)
 348          */
 349         switch (action) {
 350         case REF_INCREMENT:
 351
 352                 new_count++;
 353                 object->common.reference_count = new_count;
 354
 355                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 356                                   "Obj %p Refs=%X, [Incremented]\n",
 357                                   object, new_count));
 358                 break;
 359
 360         case REF_DECREMENT:
 361
 362                 if (count < 1) {
 363                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 364                                           "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
 365                                           object, new_count));
 366
 367                         new_count = 0;
 368                 } else {
 369                         new_count--;
 370
 371                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 372                                           "Obj %p Refs=%X, [Decremented]\n",
 373                                           object, new_count));
 374                 }
 375
 376                 if (ACPI_GET_OBJECT_TYPE(object) == ACPI_TYPE_METHOD) {
 377                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 378                                           "Method Obj %p Refs=%X, [Decremented]\n",
 379                                           object, new_count));
 380                 }
 381
 382                 object->common.reference_count = new_count;
 383                 if (new_count == 0) {
 384                         acpi_ut_delete_internal_obj(object);
 385                 }
 386                 break;
 387
 388         case REF_FORCE_DELETE:
 389
 390                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 391                                   "Obj %p Refs=%X, Force delete! (Set to 0)\n",
 392                                   object, count));
 393
 394                 new_count = 0;
 395                 object->common.reference_count = new_count;
 396                 acpi_ut_delete_internal_obj(object);
 397                 break;
 398
 399         default:
 400
 401                 ACPI_ERROR((AE_INFO, "Unknown action (%X)", action));
 402                 break;
 403         }
 404
 405         /*
 406          * Sanity check the reference count, for debug purposes only.
 407          * (A deleted object will have a huge reference count)
 408          */
 409         if (count > ACPI_MAX_REFERENCE_COUNT) {
 410                 ACPI_WARNING((AE_INFO,
 411                               "Large Reference Count (%X) in object %p", count,
 412                               object));
 413         }
 414 }
 415
 416 /*******************************************************************************
 417  *
 418  * FUNCTION:    acpi_ut_update_object_reference
 419  *
 420  * PARAMETERS:  Object              - Increment ref count for this object
 421  *                                    and all sub-objects
 422  *              Action              - Either REF_INCREMENT or REF_DECREMENT or
 423  *                                    REF_FORCE_DELETE
 424  *
 425  * RETURN:      Status
 426  *
 427  * DESCRIPTION: Increment the object reference count
 428  *
 429  * Object references are incremented when:
 430  * 1) An object is attached to a Node (namespace object)
 431  * 2) An object is copied (all subobjects must be incremented)
 432  *
 433  * Object references are decremented when:
 434  * 1) An object is detached from an Node
 435  *
 436  ******************************************************************************/
 437
 438 acpi_status
 439 acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
 440 {
 441         acpi_status status = AE_OK;
 442         union acpi_generic_state *state_list = NULL;
 443         union acpi_operand_object *next_object = NULL;
 444         union acpi_generic_state *state;
 445         acpi_native_uint i;
 446
 447         ACPI_FUNCTION_TRACE_PTR(ut_update_object_reference, object);
 448
 449         while (object) {
 450
 451                 /* Make sure that this isn't a namespace handle */
 452
 453                 if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
 454                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 455                                           "Object %p is NS handle\n", object));
 456                         return_ACPI_STATUS(AE_OK);
 457                 }
 458
 459                 /*
 460                  * All sub-objects must have their reference count incremented also.
 461                  * Different object types have different subobjects.
 462                  */
 463                 switch (ACPI_GET_OBJECT_TYPE(object)) {
 464                 case ACPI_TYPE_DEVICE:
 465                 case ACPI_TYPE_PROCESSOR:
 466                 case ACPI_TYPE_POWER:
 467                 case ACPI_TYPE_THERMAL:
 468
 469                         /* Update the notify objects for these types (if present) */
 470
 471                         acpi_ut_update_ref_count(object->common_notify.
 472                                                  system_notify, action);
 473                         acpi_ut_update_ref_count(object->common_notify.
 474                                                  device_notify, action);
 475                         break;
 476
 477                 case ACPI_TYPE_PACKAGE:
 478                         /*
 479                          * We must update all the sub-objects of the package,
 480                          * each of whom may have their own sub-objects.
 481                          */
 482                         for (i = 0; i < object->package.count; i++) {
 483                                 /*
 484                                  * Push each element onto the stack for later processing.
 485                                  * Note: There can be null elements within the package,
 486                                  * these are simply ignored
 487                                  */
 488                                 status =
 489                                     acpi_ut_create_update_state_and_push
 490                                     (object->package.elements[i], action,
 491                                      &state_list);
 492                                 if (ACPI_FAILURE(status)) {
 493                                         goto error_exit;
 494                                 }
 495                         }
 496                         break;
 497
 498                 case ACPI_TYPE_BUFFER_FIELD:
 499
 500                         next_object = object->buffer_field.buffer_obj;
 501                         break;
 502
 503                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 504
 505                         next_object = object->field.region_obj;
 506                         break;
 507
 508                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 509
 510                         next_object = object->bank_field.bank_obj;
 511                         status =
 512                             acpi_ut_create_update_state_and_push(object->
 513                                                                  bank_field.
 514                                                                  region_obj,
 515                                                                  action,
 516                                                                  &state_list);
 517                         if (ACPI_FAILURE(status)) {
 518                                 goto error_exit;
 519                         }
 520                         break;
 521
 522                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
 523
 524                         next_object = object->index_field.index_obj;
 525                         status =
 526                             acpi_ut_create_update_state_and_push(object->
 527                                                                  index_field.
 528                                                                  data_obj,
 529                                                                  action,
 530                                                                  &state_list);
 531                         if (ACPI_FAILURE(status)) {
 532                                 goto error_exit;
 533                         }
 534                         break;
 535
 536                 case ACPI_TYPE_LOCAL_REFERENCE:
 537                         /*
 538                          * The target of an Index (a package, string, or buffer) or a named
 539                          * reference must track changes to the ref count of the index or
 540                          * target object.
 541                          */
 542                         if ((object->reference.opcode == AML_INDEX_OP) ||
 543                             (object->reference.opcode == AML_INT_NAMEPATH_OP)) {
 544                                 next_object = object->reference.object;
 545                         }
 546                         break;
 547
 548                 case ACPI_TYPE_REGION:
 549                 default:
 550                         break;  /* No subobjects for all other types */
 551                 }
 552
 553                 /*
 554                  * Now we can update the count in the main object. This can only
 555                  * happen after we update the sub-objects in case this causes the
 556                  * main object to be deleted.
 557                  */
 558                 acpi_ut_update_ref_count(object, action);
 559                 object = NULL;
 560
 561                 /* Move on to the next object to be updated */
 562
 563                 if (next_object) {
 564                         object = next_object;
 565                         next_object = NULL;
 566                 } else if (state_list) {
 567                         state = acpi_ut_pop_generic_state(&state_list);
 568                         object = state->update.object;
 569                         acpi_ut_delete_generic_state(state);
 570                 }
 571         }
 572
 573         return_ACPI_STATUS(AE_OK);
 574
 575       error_exit:
 576
 577         ACPI_EXCEPTION((AE_INFO, status,
 578                         "Could not update object reference count"));
 579
 580         return_ACPI_STATUS(status);
 581 }
 582
 583 /*******************************************************************************
 584  *
 585  * FUNCTION:    acpi_ut_add_reference
 586  *
 587  * PARAMETERS:  Object          - Object whose reference count is to be
 588  *                                incremented
 589  *
 590  * RETURN:      None
 591  *
 592  * DESCRIPTION: Add one reference to an ACPI object
 593  *
 594  ******************************************************************************/
 595
 596 void acpi_ut_add_reference(union acpi_operand_object *object)
 597 {
 598
 599         ACPI_FUNCTION_TRACE_PTR(ut_add_reference, object);
 600
 601         /* Ensure that we have a valid object */
 602
 603         if (!acpi_ut_valid_internal_object(object)) {
 604                 return_VOID;
 605         }
 606
 607         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 608                           "Obj %p Current Refs=%X [To Be Incremented]\n",
 609                           object, object->common.reference_count));
 610
 611         /* Increment the reference count */
 612
 613         (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
 614         return_VOID;
 615 }
 616
 617 /*******************************************************************************
 618  *
 619  * FUNCTION:    acpi_ut_remove_reference
 620  *
 621  * PARAMETERS:  Object         - Object whose ref count will be decremented
 622  *
 623  * RETURN:      None
 624  *
 625  * DESCRIPTION: Decrement the reference count of an ACPI internal object
 626  *
 627  ******************************************************************************/
 628
 629 void acpi_ut_remove_reference(union acpi_operand_object *object)
 630 {
 631
 632         ACPI_FUNCTION_TRACE_PTR(ut_remove_reference, object);
 633
 634         /*
 635          * Allow a NULL pointer to be passed in, just ignore it. This saves
 636          * each caller from having to check. Also, ignore NS nodes.
 637          *
 638          */
 639         if (!object ||
 640             (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
 641                 return_VOID;
 642         }
 643
 644         /* Ensure that we have a valid object */
 645
 646         if (!acpi_ut_valid_internal_object(object)) {
 647                 return_VOID;
 648         }
 649
 650         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 651                           "Obj %p Current Refs=%X [To Be Decremented]\n",
 652                           object, object->common.reference_count));
 653
 654         /*
 655          * Decrement the reference count, and only actually delete the object
 656          * if the reference count becomes 0. (Must also decrement the ref count
 657          * of all subobjects!)
 658          */
 659         (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
 660         return_VOID;
 661 }