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