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   1 /*******************************************************************************
   2  *
   3  * Module Name: utdelete - object deletion and reference count utilities
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2005, 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
  45 #include <acpi/acpi.h>
  46 #include <acpi/acinterp.h>
  47 #include <acpi/acnamesp.h>
  48 #include <acpi/acevents.h>
  49 #include <acpi/amlcode.h>
  50
  51 #define _COMPONENT          ACPI_UTILITIES
  52          ACPI_MODULE_NAME    ("utdelete")
  53
  54 /* Local prototypes */
  55
  56 static void
  57 acpi_ut_delete_internal_obj (
  58         union acpi_operand_object       *object);
  59
  60 static void
  61 acpi_ut_update_ref_count (
  62         union acpi_operand_object       *object,
  63         u32                             action);
  64
  65
  66 /*******************************************************************************
  67  *
  68  * FUNCTION:    acpi_ut_delete_internal_obj
  69  *
  70  * PARAMETERS:  Object         - Object to be deleted
  71  *
  72  * RETURN:      None
  73  *
  74  * DESCRIPTION: Low level object deletion, after reference counts have been
  75  *              updated (All reference counts, including sub-objects!)
  76  *
  77  ******************************************************************************/
  78
  79 static void
  80 acpi_ut_delete_internal_obj (
  81         union acpi_operand_object       *object)
  82 {
  83         void                            *obj_pointer = NULL;
  84         union acpi_operand_object       *handler_desc;
  85         union acpi_operand_object       *second_desc;
  86         union acpi_operand_object       *next_desc;
  87
  88
  89         ACPI_FUNCTION_TRACE_PTR ("ut_delete_internal_obj", object);
  90
  91
  92         if (!object) {
  93                 return_VOID;
  94         }
  95
  96         /*
  97          * Must delete or free any pointers within the object that are not
  98          * actual ACPI objects (for example, a raw buffer pointer).
  99          */
 100         switch (ACPI_GET_OBJECT_TYPE (object)) {
 101         case ACPI_TYPE_STRING:
 102
 103                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "**** String %p, ptr %p\n",
 104                         object, object->string.pointer));
 105
 106                 /* Free the actual string buffer */
 107
 108                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
 109                         /* But only if it is NOT a pointer into an ACPI table */
 110
 111                         obj_pointer = object->string.pointer;
 112                 }
 113                 break;
 114
 115
 116         case ACPI_TYPE_BUFFER:
 117
 118                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "**** Buffer %p, ptr %p\n",
 119                         object, object->buffer.pointer));
 120
 121                 /* Free the actual buffer */
 122
 123                 if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {
 124                         /* But only if it is NOT a pointer into an ACPI table */
 125
 126                         obj_pointer = object->buffer.pointer;
 127                 }
 128                 break;
 129
 130
 131         case ACPI_TYPE_PACKAGE:
 132
 133                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, " **** Package of count %X\n",
 134                         object->package.count));
 135
 136                 /*
 137                  * Elements of the package are not handled here, they are deleted
 138                  * separately
 139                  */
 140
 141                 /* Free the (variable length) element pointer array */
 142
 143                 obj_pointer = object->package.elements;
 144                 break;
 145
 146
 147         case ACPI_TYPE_DEVICE:
 148
 149                 if (object->device.gpe_block) {
 150                         (void) acpi_ev_delete_gpe_block (object->device.gpe_block);
 151                 }
 152
 153                 /* Walk the handler list for this device */
 154
 155                 handler_desc = object->device.handler;
 156                 while (handler_desc) {
 157                         next_desc = handler_desc->address_space.next;
 158                         acpi_ut_remove_reference (handler_desc);
 159                         handler_desc = next_desc;
 160                 }
 161                 break;
 162
 163
 164         case ACPI_TYPE_MUTEX:
 165
 166                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 167                         "***** Mutex %p, Semaphore %p\n",
 168                         object, object->mutex.semaphore));
 169
 170                 acpi_ex_unlink_mutex (object);
 171                 (void) acpi_os_delete_semaphore (object->mutex.semaphore);
 172                 break;
 173
 174
 175         case ACPI_TYPE_EVENT:
 176
 177                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 178                         "***** Event %p, Semaphore %p\n",
 179                         object, object->event.semaphore));
 180
 181                 (void) acpi_os_delete_semaphore (object->event.semaphore);
 182                 object->event.semaphore = NULL;
 183                 break;
 184
 185
 186         case ACPI_TYPE_METHOD:
 187
 188                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 189                         "***** Method %p\n", object));
 190
 191                 /* Delete the method semaphore if it exists */
 192
 193                 if (object->method.semaphore) {
 194                         (void) acpi_os_delete_semaphore (object->method.semaphore);
 195                         object->method.semaphore = NULL;
 196                 }
 197                 break;
 198
 199
 200         case ACPI_TYPE_REGION:
 201
 202                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 203                         "***** Region %p\n", object));
 204
 205                 second_desc = acpi_ns_get_secondary_object (object);
 206                 if (second_desc) {
 207                         /*
 208                          * Free the region_context if and only if the handler is one of the
 209                          * default handlers -- and therefore, we created the context object
 210                          * locally, it was not created by an external caller.
 211                          */
 212                         handler_desc = object->region.handler;
 213                         if (handler_desc) {
 214                                 if (handler_desc->address_space.hflags & ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
 215                                         obj_pointer = second_desc->extra.region_context;
 216                                 }
 217
 218                                 acpi_ut_remove_reference (handler_desc);
 219                         }
 220
 221                         /* Now we can free the Extra object */
 222
 223                         acpi_ut_delete_object_desc (second_desc);
 224                 }
 225                 break;
 226
 227
 228         case ACPI_TYPE_BUFFER_FIELD:
 229
 230                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 231                         "***** Buffer Field %p\n", object));
 232
 233                 second_desc = acpi_ns_get_secondary_object (object);
 234                 if (second_desc) {
 235                         acpi_ut_delete_object_desc (second_desc);
 236                 }
 237                 break;
 238
 239
 240         default:
 241                 break;
 242         }
 243
 244         /* Free any allocated memory (pointer within the object) found above */
 245
 246         if (obj_pointer) {
 247                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Deleting Object Subptr %p\n",
 248                                 obj_pointer));
 249                 ACPI_MEM_FREE (obj_pointer);
 250         }
 251
 252         /* Now the object can be safely deleted */
 253
 254         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
 255                         object, acpi_ut_get_object_type_name (object)));
 256
 257         acpi_ut_delete_object_desc (object);
 258         return_VOID;
 259 }
 260
 261
 262 /*******************************************************************************
 263  *
 264  * FUNCTION:    acpi_ut_delete_internal_object_list
 265  *
 266  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 267  *
 268  * RETURN:      None
 269  *
 270  * DESCRIPTION: This function deletes an internal object list, including both
 271  *              simple objects and package objects
 272  *
 273  ******************************************************************************/
 274
 275 void
 276 acpi_ut_delete_internal_object_list (
 277         union acpi_operand_object       **obj_list)
 278 {
 279         union acpi_operand_object       **internal_obj;
 280
 281
 282         ACPI_FUNCTION_TRACE ("ut_delete_internal_object_list");
 283
 284
 285         /* Walk the null-terminated internal list */
 286
 287         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
 288                 acpi_ut_remove_reference (*internal_obj);
 289         }
 290
 291         /* Free the combined parameter pointer list and object array */
 292
 293         ACPI_MEM_FREE (obj_list);
 294         return_VOID;
 295 }
 296
 297
 298 /*******************************************************************************
 299  *
 300  * FUNCTION:    acpi_ut_update_ref_count
 301  *
 302  * PARAMETERS:  Object          - Object whose ref count is to be updated
 303  *              Action          - What to do
 304  *
 305  * RETURN:      New ref count
 306  *
 307  * DESCRIPTION: Modify the ref count and return it.
 308  *
 309  ******************************************************************************/
 310
 311 static void
 312 acpi_ut_update_ref_count (
 313         union acpi_operand_object       *object,
 314         u32                             action)
 315 {
 316         u16                             count;
 317         u16                             new_count;
 318
 319
 320         ACPI_FUNCTION_NAME ("ut_update_ref_count");
 321
 322
 323         if (!object) {
 324                 return;
 325         }
 326
 327         count = object->common.reference_count;
 328         new_count = count;
 329
 330         /*
 331          * Perform the reference count action
 332          * (increment, decrement, or force delete)
 333          */
 334         switch (action) {
 335
 336         case REF_INCREMENT:
 337
 338                 new_count++;
 339                 object->common.reference_count = new_count;
 340
 341                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 342                         "Obj %p Refs=%X, [Incremented]\n",
 343                         object, new_count));
 344                 break;
 345
 346
 347         case REF_DECREMENT:
 348
 349                 if (count < 1) {
 350                         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 351                                 "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
 352                                 object, new_count));
 353
 354                         new_count = 0;
 355                 }
 356                 else {
 357                         new_count--;
 358
 359                         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 360                                 "Obj %p Refs=%X, [Decremented]\n",
 361                                 object, new_count));
 362                 }
 363
 364                 if (ACPI_GET_OBJECT_TYPE (object) == ACPI_TYPE_METHOD) {
 365                         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 366                                 "Method Obj %p Refs=%X, [Decremented]\n",
 367                                 object, new_count));
 368                 }
 369
 370                 object->common.reference_count = new_count;
 371                 if (new_count == 0) {
 372                         acpi_ut_delete_internal_obj (object);
 373                 }
 374
 375                 break;
 376
 377
 378         case REF_FORCE_DELETE:
 379
 380                 ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 381                         "Obj %p Refs=%X, Force delete! (Set to 0)\n",
 382                         object, count));
 383
 384                 new_count = 0;
 385                 object->common.reference_count = new_count;
 386                 acpi_ut_delete_internal_obj (object);
 387                 break;
 388
 389
 390         default:
 391
 392                 ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Unknown action (%X)\n", action));
 393                 break;
 394         }
 395
 396         /*
 397          * Sanity check the reference count, for debug purposes only.
 398          * (A deleted object will have a huge reference count)
 399          */
 400         if (count > ACPI_MAX_REFERENCE_COUNT) {
 401
 402                 ACPI_DEBUG_PRINT ((ACPI_DB_WARN,
 403                         "**** Warning **** Large Reference Count (%X) in object %p\n\n",
 404                         count, object));
 405         }
 406
 407         return;
 408 }
 409
 410
 411 /*******************************************************************************
 412  *
 413  * FUNCTION:    acpi_ut_update_object_reference
 414  *
 415  * PARAMETERS:  Object              - Increment ref count for this object
 416  *                                    and all sub-objects
 417  *              Action              - Either REF_INCREMENT or REF_DECREMENT or
 418  *                                    REF_FORCE_DELETE
 419  *
 420  * RETURN:      Status
 421  *
 422  * DESCRIPTION: Increment the object reference count
 423  *
 424  * Object references are incremented when:
 425  * 1) An object is attached to a Node (namespace object)
 426  * 2) An object is copied (all subobjects must be incremented)
 427  *
 428  * Object references are decremented when:
 429  * 1) An object is detached from an Node
 430  *
 431  ******************************************************************************/
 432
 433 acpi_status
 434 acpi_ut_update_object_reference (
 435         union acpi_operand_object       *object,
 436         u16                             action)
 437 {
 438         acpi_status                     status = AE_OK;
 439         union acpi_generic_state        *state_list = NULL;
 440         union acpi_operand_object       *next_object = NULL;
 441         union acpi_generic_state        *state;
 442         acpi_native_uint                i;
 443
 444
 445         ACPI_FUNCTION_TRACE_PTR ("ut_update_object_reference", object);
 446
 447
 448         while (object) {
 449                 /* Make sure that this isn't a namespace handle */
 450
 451                 if (ACPI_GET_DESCRIPTOR_TYPE (object) == ACPI_DESC_TYPE_NAMED) {
 452                         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 453                                 "Object %p is NS handle\n", object));
 454                         return_ACPI_STATUS (AE_OK);
 455                 }
 456
 457                 /*
 458                  * All sub-objects must have their reference count incremented also.
 459                  * Different object types have different subobjects.
 460                  */
 461                 switch (ACPI_GET_OBJECT_TYPE (object)) {
 462                 case ACPI_TYPE_DEVICE:
 463
 464                         acpi_ut_update_ref_count (object->device.system_notify, action);
 465                         acpi_ut_update_ref_count (object->device.device_notify, action);
 466                         break;
 467
 468                 case ACPI_TYPE_PACKAGE:
 469                         /*
 470                          * We must update all the sub-objects of the package,
 471                          * each of whom may have their own sub-objects.
 472                          */
 473                         for (i = 0; i < object->package.count; i++) {
 474                                 /*
 475                                  * Push each element onto the stack for later processing.
 476                                  * Note: There can be null elements within the package,
 477                                  * these are simply ignored
 478                                  */
 479                                 status = acpi_ut_create_update_state_and_push (
 480                                                  object->package.elements[i], action, &state_list);
 481                                 if (ACPI_FAILURE (status)) {
 482                                         goto error_exit;
 483                                 }
 484                         }
 485                         break;
 486
 487                 case ACPI_TYPE_BUFFER_FIELD:
 488
 489                         next_object = object->buffer_field.buffer_obj;
 490                         break;
 491
 492                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 493
 494                         next_object = object->field.region_obj;
 495                         break;
 496
 497                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 498
 499                         next_object = object->bank_field.bank_obj;
 500                         status = acpi_ut_create_update_state_and_push (
 501                                          object->bank_field.region_obj, action, &state_list);
 502                         if (ACPI_FAILURE (status)) {
 503                                 goto error_exit;
 504                         }
 505                         break;
 506
 507                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
 508
 509                         next_object = object->index_field.index_obj;
 510                         status = acpi_ut_create_update_state_and_push (
 511                                          object->index_field.data_obj, action, &state_list);
 512                         if (ACPI_FAILURE (status)) {
 513                                 goto error_exit;
 514                         }
 515                         break;
 516
 517                 case ACPI_TYPE_LOCAL_REFERENCE:
 518                         /*
 519                          * The target of an Index (a package, string, or buffer) must track
 520                          * changes to the ref count of the index.
 521                          */
 522                         if (object->reference.opcode == AML_INDEX_OP) {
 523                                 next_object = object->reference.object;
 524                         }
 525                         break;
 526
 527                 case ACPI_TYPE_REGION:
 528                 default:
 529                         break;/* No subobjects */
 530                 }
 531
 532                 /*
 533                  * Now we can update the count in the main object.  This can only
 534                  * happen after we update the sub-objects in case this causes the
 535                  * main object to be deleted.
 536                  */
 537                 acpi_ut_update_ref_count (object, action);
 538                 object = NULL;
 539
 540                 /* Move on to the next object to be updated */
 541
 542                 if (next_object) {
 543                         object = next_object;
 544                         next_object = NULL;
 545                 }
 546                 else if (state_list) {
 547                         state = acpi_ut_pop_generic_state (&state_list);
 548                         object = state->update.object;
 549                         acpi_ut_delete_generic_state (state);
 550                 }
 551         }
 552
 553         return_ACPI_STATUS (AE_OK);
 554
 555 error_exit:
 556
 557         ACPI_REPORT_ERROR (("Could not update object reference count, %s\n",
 558                 acpi_format_exception (status)));
 559
 560         return_ACPI_STATUS (status);
 561 }
 562
 563
 564 /*******************************************************************************
 565  *
 566  * FUNCTION:    acpi_ut_add_reference
 567  *
 568  * PARAMETERS:  Object          - Object whose reference count is to be
 569  *                                incremented
 570  *
 571  * RETURN:      None
 572  *
 573  * DESCRIPTION: Add one reference to an ACPI object
 574  *
 575  ******************************************************************************/
 576
 577 void
 578 acpi_ut_add_reference (
 579         union acpi_operand_object       *object)
 580 {
 581
 582         ACPI_FUNCTION_TRACE_PTR ("ut_add_reference", object);
 583
 584
 585         /* Ensure that we have a valid object */
 586
 587         if (!acpi_ut_valid_internal_object (object)) {
 588                 return_VOID;
 589         }
 590
 591         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 592                 "Obj %p Current Refs=%X [To Be Incremented]\n",
 593                 object, object->common.reference_count));
 594
 595         /* Increment the reference count */
 596
 597         (void) acpi_ut_update_object_reference (object, REF_INCREMENT);
 598         return_VOID;
 599 }
 600
 601
 602 /*******************************************************************************
 603  *
 604  * FUNCTION:    acpi_ut_remove_reference
 605  *
 606  * PARAMETERS:  Object         - Object whose ref count will be decremented
 607  *
 608  * RETURN:      None
 609  *
 610  * DESCRIPTION: Decrement the reference count of an ACPI internal object
 611  *
 612  ******************************************************************************/
 613
 614 void
 615 acpi_ut_remove_reference (
 616         union acpi_operand_object       *object)
 617 {
 618
 619         ACPI_FUNCTION_TRACE_PTR ("ut_remove_reference", object);
 620
 621
 622         /*
 623          * Allow a NULL pointer to be passed in, just ignore it.  This saves
 624          * each caller from having to check.  Also, ignore NS nodes.
 625          *
 626          */
 627         if (!object ||
 628                 (ACPI_GET_DESCRIPTOR_TYPE (object) == ACPI_DESC_TYPE_NAMED)) {
 629                 return_VOID;
 630         }
 631
 632         /* Ensure that we have a valid object */
 633
 634         if (!acpi_ut_valid_internal_object (object)) {
 635                 return_VOID;
 636         }
 637
 638         ACPI_DEBUG_PRINT ((ACPI_DB_ALLOCATIONS,
 639                 "Obj %p Current Refs=%X [To Be Decremented]\n",
 640                 object, object->common.reference_count));
 641
 642         /*
 643          * Decrement the reference count, and only actually delete the object
 644          * if the reference count becomes 0.  (Must also decrement the ref count
 645          * of all subobjects!)
 646          */
 647         (void) acpi_ut_update_object_reference (object, REF_DECREMENT);
 648         return_VOID;
 649 }
 650
 651