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 - 2006, 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->mutex.os_mutex != ACPI_GLOBAL_LOCK) {
 162                         acpi_ex_unlink_mutex(object);
 163                         acpi_os_delete_mutex(object->mutex.os_mutex);
 164                 } else {
 165                         /* Global Lock "mutex" is actually a counting semaphore */
 166
 167                         (void)
 168                             acpi_os_delete_semaphore
 169                             (acpi_gbl_global_lock_semaphore);
 170                         acpi_gbl_global_lock_semaphore = NULL;
 171                 }
 172                 break;
 173
 174         case ACPI_TYPE_EVENT:
 175
 176                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 177                                   "***** Event %p, OS Semaphore %p\n",
 178                                   object, object->event.os_semaphore));
 179
 180                 (void)acpi_os_delete_semaphore(object->event.os_semaphore);
 181                 object->event.os_semaphore = NULL;
 182                 break;
 183
 184         case ACPI_TYPE_METHOD:
 185
 186                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 187                                   "***** Method %p\n", object));
 188
 189                 /* Delete the method mutex if it exists */
 190
 191                 if (object->method.mutex) {
 192                         acpi_os_delete_mutex(object->method.mutex->mutex.
 193                                              os_mutex);
 194                         acpi_ut_delete_object_desc(object->method.mutex);
 195                         object->method.mutex = NULL;
 196                 }
 197                 break;
 198
 199         case ACPI_TYPE_REGION:
 200
 201                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 202                                   "***** Region %p\n", object));
 203
 204                 second_desc = acpi_ns_get_secondary_object(object);
 205                 if (second_desc) {
 206                         /*
 207                          * Free the region_context if and only if the handler is one of the
 208                          * default handlers -- and therefore, we created the context object
 209                          * locally, it was not created by an external caller.
 210                          */
 211                         handler_desc = object->region.handler;
 212                         if (handler_desc) {
 213                                 if (handler_desc->address_space.handler_flags &
 214                                     ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
 215
 216                                         /* Deactivate region and free region context */
 217
 218                                         if (handler_desc->address_space.setup) {
 219                                                 (void)handler_desc->
 220                                                     address_space.setup(object,
 221                                                                         ACPI_REGION_DEACTIVATE,
 222                                                                         handler_desc->
 223                                                                         address_space.
 224                                                                         context,
 225                                                                         &second_desc->
 226                                                                         extra.
 227                                                                         region_context);
 228                                         }
 229                                 }
 230
 231                                 acpi_ut_remove_reference(handler_desc);
 232                         }
 233
 234                         /* Now we can free the Extra object */
 235
 236                         acpi_ut_delete_object_desc(second_desc);
 237                 }
 238                 break;
 239
 240         case ACPI_TYPE_BUFFER_FIELD:
 241
 242                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 243                                   "***** Buffer Field %p\n", object));
 244
 245                 second_desc = acpi_ns_get_secondary_object(object);
 246                 if (second_desc) {
 247                         acpi_ut_delete_object_desc(second_desc);
 248                 }
 249                 break;
 250
 251         default:
 252                 break;
 253         }
 254
 255         /* Free any allocated memory (pointer within the object) found above */
 256
 257         if (obj_pointer) {
 258                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 259                                   "Deleting Object Subptr %p\n", obj_pointer));
 260                 ACPI_FREE(obj_pointer);
 261         }
 262
 263         /* Now the object can be safely deleted */
 264
 265         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
 266                           object, acpi_ut_get_object_type_name(object)));
 267
 268         acpi_ut_delete_object_desc(object);
 269         return_VOID;
 270 }
 271
 272 /*******************************************************************************
 273  *
 274  * FUNCTION:    acpi_ut_delete_internal_object_list
 275  *
 276  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 277  *
 278  * RETURN:      None
 279  *
 280  * DESCRIPTION: This function deletes an internal object list, including both
 281  *              simple objects and package objects
 282  *
 283  ******************************************************************************/
 284
 285 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
 286 {
 287         union acpi_operand_object **internal_obj;
 288
 289         ACPI_FUNCTION_TRACE(ut_delete_internal_object_list);
 290
 291         /* Walk the null-terminated internal list */
 292
 293         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
 294                 acpi_ut_remove_reference(*internal_obj);
 295         }
 296
 297         /* Free the combined parameter pointer list and object array */
 298
 299         ACPI_FREE(obj_list);
 300         return_VOID;
 301 }
 302
 303 /*******************************************************************************
 304  *
 305  * FUNCTION:    acpi_ut_update_ref_count
 306  *
 307  * PARAMETERS:  Object          - Object whose ref count is to be updated
 308  *              Action          - What to do
 309  *
 310  * RETURN:      New ref count
 311  *
 312  * DESCRIPTION: Modify the ref count and return it.
 313  *
 314  ******************************************************************************/
 315
 316 static void
 317 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
 318 {
 319         u16 count;
 320         u16 new_count;
 321
 322         ACPI_FUNCTION_NAME(ut_update_ref_count);
 323
 324         if (!object) {
 325                 return;
 326         }
 327
 328         count = object->common.reference_count;
 329         new_count = count;
 330
 331         /*
 332          * Perform the reference count action (increment, decrement, force delete)
 333          */
 334         switch (action) {
 335         case REF_INCREMENT:
 336
 337                 new_count++;
 338                 object->common.reference_count = new_count;
 339
 340                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 341                                   "Obj %p Refs=%X, [Incremented]\n",
 342                                   object, new_count));
 343                 break;
 344
 345         case REF_DECREMENT:
 346
 347                 if (count < 1) {
 348                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 349                                           "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
 350                                           object, new_count));
 351
 352                         new_count = 0;
 353                 } else {
 354                         new_count--;
 355
 356                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 357                                           "Obj %p Refs=%X, [Decremented]\n",
 358                                           object, new_count));
 359                 }
 360
 361                 if (ACPI_GET_OBJECT_TYPE(object) == ACPI_TYPE_METHOD) {
 362                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 363                                           "Method Obj %p Refs=%X, [Decremented]\n",
 364                                           object, new_count));
 365                 }
 366
 367                 object->common.reference_count = new_count;
 368                 if (new_count == 0) {
 369                         acpi_ut_delete_internal_obj(object);
 370                 }
 371                 break;
 372
 373         case REF_FORCE_DELETE:
 374
 375                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 376                                   "Obj %p Refs=%X, Force delete! (Set to 0)\n",
 377                                   object, count));
 378
 379                 new_count = 0;
 380                 object->common.reference_count = new_count;
 381                 acpi_ut_delete_internal_obj(object);
 382                 break;
 383
 384         default:
 385
 386                 ACPI_ERROR((AE_INFO, "Unknown action (%X)", action));
 387                 break;
 388         }
 389
 390         /*
 391          * Sanity check the reference count, for debug purposes only.
 392          * (A deleted object will have a huge reference count)
 393          */
 394         if (count > ACPI_MAX_REFERENCE_COUNT) {
 395                 ACPI_WARNING((AE_INFO,
 396                               "Large Reference Count (%X) in object %p", count,
 397                               object));
 398         }
 399 }
 400
 401 /*******************************************************************************
 402  *
 403  * FUNCTION:    acpi_ut_update_object_reference
 404  *
 405  * PARAMETERS:  Object              - Increment ref count for this object
 406  *                                    and all sub-objects
 407  *              Action              - Either REF_INCREMENT or REF_DECREMENT or
 408  *                                    REF_FORCE_DELETE
 409  *
 410  * RETURN:      Status
 411  *
 412  * DESCRIPTION: Increment the object reference count
 413  *
 414  * Object references are incremented when:
 415  * 1) An object is attached to a Node (namespace object)
 416  * 2) An object is copied (all subobjects must be incremented)
 417  *
 418  * Object references are decremented when:
 419  * 1) An object is detached from an Node
 420  *
 421  ******************************************************************************/
 422
 423 acpi_status
 424 acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
 425 {
 426         acpi_status status = AE_OK;
 427         union acpi_generic_state *state_list = NULL;
 428         union acpi_operand_object *next_object = NULL;
 429         union acpi_generic_state *state;
 430         acpi_native_uint i;
 431
 432         ACPI_FUNCTION_TRACE_PTR(ut_update_object_reference, object);
 433
 434         while (object) {
 435
 436                 /* Make sure that this isn't a namespace handle */
 437
 438                 if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
 439                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 440                                           "Object %p is NS handle\n", object));
 441                         return_ACPI_STATUS(AE_OK);
 442                 }
 443
 444                 /*
 445                  * All sub-objects must have their reference count incremented also.
 446                  * Different object types have different subobjects.
 447                  */
 448                 switch (ACPI_GET_OBJECT_TYPE(object)) {
 449                 case ACPI_TYPE_DEVICE:
 450                 case ACPI_TYPE_PROCESSOR:
 451                 case ACPI_TYPE_POWER:
 452                 case ACPI_TYPE_THERMAL:
 453
 454                         /* Update the notify objects for these types (if present) */
 455
 456                         acpi_ut_update_ref_count(object->common_notify.
 457                                                  system_notify, action);
 458                         acpi_ut_update_ref_count(object->common_notify.
 459                                                  device_notify, action);
 460                         break;
 461
 462                 case ACPI_TYPE_PACKAGE:
 463                         /*
 464                          * We must update all the sub-objects of the package,
 465                          * each of whom may have their own sub-objects.
 466                          */
 467                         for (i = 0; i < object->package.count; i++) {
 468                                 /*
 469                                  * Push each element onto the stack for later processing.
 470                                  * Note: There can be null elements within the package,
 471                                  * these are simply ignored
 472                                  */
 473                                 status =
 474                                     acpi_ut_create_update_state_and_push
 475                                     (object->package.elements[i], action,
 476                                      &state_list);
 477                                 if (ACPI_FAILURE(status)) {
 478                                         goto error_exit;
 479                                 }
 480                         }
 481                         break;
 482
 483                 case ACPI_TYPE_BUFFER_FIELD:
 484
 485                         next_object = object->buffer_field.buffer_obj;
 486                         break;
 487
 488                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 489
 490                         next_object = object->field.region_obj;
 491                         break;
 492
 493                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 494
 495                         next_object = object->bank_field.bank_obj;
 496                         status =
 497                             acpi_ut_create_update_state_and_push(object->
 498                                                                  bank_field.
 499                                                                  region_obj,
 500                                                                  action,
 501                                                                  &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 =
 511                             acpi_ut_create_update_state_and_push(object->
 512                                                                  index_field.
 513                                                                  data_obj,
 514                                                                  action,
 515                                                                  &state_list);
 516                         if (ACPI_FAILURE(status)) {
 517                                 goto error_exit;
 518                         }
 519                         break;
 520
 521                 case ACPI_TYPE_LOCAL_REFERENCE:
 522                         /*
 523                          * The target of an Index (a package, string, or buffer) must track
 524                          * changes to the ref count of the index.
 525                          */
 526                         if (object->reference.opcode == AML_INDEX_OP) {
 527                                 next_object = object->reference.object;
 528                         }
 529                         break;
 530
 531                 case ACPI_TYPE_REGION:
 532                 default:
 533                         break;  /* No subobjects for all other types */
 534                 }
 535
 536                 /*
 537                  * Now we can update the count in the main object. This can only
 538                  * happen after we update the sub-objects in case this causes the
 539                  * main object to be deleted.
 540                  */
 541                 acpi_ut_update_ref_count(object, action);
 542                 object = NULL;
 543
 544                 /* Move on to the next object to be updated */
 545
 546                 if (next_object) {
 547                         object = next_object;
 548                         next_object = NULL;
 549                 } else if (state_list) {
 550                         state = acpi_ut_pop_generic_state(&state_list);
 551                         object = state->update.object;
 552                         acpi_ut_delete_generic_state(state);
 553                 }
 554         }
 555
 556         return_ACPI_STATUS(AE_OK);
 557
 558       error_exit:
 559
 560         ACPI_EXCEPTION((AE_INFO, status,
 561                         "Could not update object reference count"));
 562
 563         return_ACPI_STATUS(status);
 564 }
 565
 566 /*******************************************************************************
 567  *
 568  * FUNCTION:    acpi_ut_add_reference
 569  *
 570  * PARAMETERS:  Object          - Object whose reference count is to be
 571  *                                incremented
 572  *
 573  * RETURN:      None
 574  *
 575  * DESCRIPTION: Add one reference to an ACPI object
 576  *
 577  ******************************************************************************/
 578
 579 void acpi_ut_add_reference(union acpi_operand_object *object)
 580 {
 581
 582         ACPI_FUNCTION_TRACE_PTR(ut_add_reference, object);
 583
 584         /* Ensure that we have a valid object */
 585
 586         if (!acpi_ut_valid_internal_object(object)) {
 587                 return_VOID;
 588         }
 589
 590         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 591                           "Obj %p Current Refs=%X [To Be Incremented]\n",
 592                           object, object->common.reference_count));
 593
 594         /* Increment the reference count */
 595
 596         (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
 597         return_VOID;
 598 }
 599
 600 /*******************************************************************************
 601  *
 602  * FUNCTION:    acpi_ut_remove_reference
 603  *
 604  * PARAMETERS:  Object         - Object whose ref count will be decremented
 605  *
 606  * RETURN:      None
 607  *
 608  * DESCRIPTION: Decrement the reference count of an ACPI internal object
 609  *
 610  ******************************************************************************/
 611
 612 void acpi_ut_remove_reference(union acpi_operand_object *object)
 613 {
 614
 615         ACPI_FUNCTION_TRACE_PTR(ut_remove_reference, object);
 616
 617         /*
 618          * Allow a NULL pointer to be passed in, just ignore it. This saves
 619          * each caller from having to check. Also, ignore NS nodes.
 620          *
 621          */
 622         if (!object ||
 623             (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
 624                 return_VOID;
 625         }
 626
 627         /* Ensure that we have a valid object */
 628
 629         if (!acpi_ut_valid_internal_object(object)) {
 630                 return_VOID;
 631         }
 632
 633         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 634                           "Obj %p Current Refs=%X [To Be Decremented]\n",
 635                           object, object->common.reference_count));
 636
 637         /*
 638          * Decrement the reference count, and only actually delete the object
 639          * if the reference count becomes 0. (Must also decrement the ref count
 640          * of all subobjects!)
 641          */
 642         (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
 643         return_VOID;
 644 }