git.oblomov.eu Git - linux-2.6/blob - 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, Semaphore %p\n",
 159                                   object, object->mutex.semaphore));
 160
 161                 acpi_ex_unlink_mutex(object);
 162                 (void)acpi_os_delete_semaphore(object->mutex.semaphore);
 163                 break;
 164
 165         case ACPI_TYPE_EVENT:
 166
 167                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 168                                   "***** Event %p, Semaphore %p\n",
 169                                   object, object->event.semaphore));
 170
 171                 (void)acpi_os_delete_semaphore(object->event.semaphore);
 172                 object->event.semaphore = NULL;
 173                 break;
 174
 175         case ACPI_TYPE_METHOD:
 176
 177                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 178                                   "***** Method %p\n", object));
 179
 180                 /* Delete the method semaphore if it exists */
 181
 182                 if (object->method.semaphore) {
 183                         (void)acpi_os_delete_semaphore(object->method.
 184                                                        semaphore);
 185                         object->method.semaphore = NULL;
 186                 }
 187                 break;
 188
 189         case ACPI_TYPE_REGION:
 190
 191                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 192                                   "***** Region %p\n", object));
 193
 194                 second_desc = acpi_ns_get_secondary_object(object);
 195                 if (second_desc) {
 196                         /*
 197                          * Free the region_context if and only if the handler is one of the
 198                          * default handlers -- and therefore, we created the context object
 199                          * locally, it was not created by an external caller.
 200                          */
 201                         handler_desc = object->region.handler;
 202                         if (handler_desc) {
 203                                 if (handler_desc->address_space.
 204                                     hflags &
 205                                     ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
 206                                         obj_pointer =
 207                                             second_desc->extra.region_context;
 208                                 }
 209
 210                                 acpi_ut_remove_reference(handler_desc);
 211                         }
 212
 213                         /* Now we can free the Extra object */
 214
 215                         acpi_ut_delete_object_desc(second_desc);
 216                 }
 217                 break;
 218
 219         case ACPI_TYPE_BUFFER_FIELD:
 220
 221                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 222                                   "***** Buffer Field %p\n", object));
 223
 224                 second_desc = acpi_ns_get_secondary_object(object);
 225                 if (second_desc) {
 226                         acpi_ut_delete_object_desc(second_desc);
 227                 }
 228                 break;
 229
 230         default:
 231                 break;
 232         }
 233
 234         /* Free any allocated memory (pointer within the object) found above */
 235
 236         if (obj_pointer) {
 237                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 238                                   "Deleting Object Subptr %p\n", obj_pointer));
 239                 ACPI_MEM_FREE(obj_pointer);
 240         }
 241
 242         /* Now the object can be safely deleted */
 243
 244         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
 245                           object, acpi_ut_get_object_type_name(object)));
 246
 247         acpi_ut_delete_object_desc(object);
 248         return_VOID;
 249 }
 250
 251 /*******************************************************************************
 252  *
 253  * FUNCTION:    acpi_ut_delete_internal_object_list
 254  *
 255  * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 256  *
 257  * RETURN:      None
 258  *
 259  * DESCRIPTION: This function deletes an internal object list, including both
 260  *              simple objects and package objects
 261  *
 262  ******************************************************************************/
 263
 264 void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
 265 {
 266         union acpi_operand_object **internal_obj;
 267
 268         ACPI_FUNCTION_TRACE("ut_delete_internal_object_list");
 269
 270         /* Walk the null-terminated internal list */
 271
 272         for (internal_obj = obj_list; *internal_obj; internal_obj++) {
 273                 acpi_ut_remove_reference(*internal_obj);
 274         }
 275
 276         /* Free the combined parameter pointer list and object array */
 277
 278         ACPI_MEM_FREE(obj_list);
 279         return_VOID;
 280 }
 281
 282 /*******************************************************************************
 283  *
 284  * FUNCTION:    acpi_ut_update_ref_count
 285  *
 286  * PARAMETERS:  Object          - Object whose ref count is to be updated
 287  *              Action          - What to do
 288  *
 289  * RETURN:      New ref count
 290  *
 291  * DESCRIPTION: Modify the ref count and return it.
 292  *
 293  ******************************************************************************/
 294
 295 static void
 296 acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
 297 {
 298         u16 count;
 299         u16 new_count;
 300
 301         ACPI_FUNCTION_NAME("ut_update_ref_count");
 302
 303         if (!object) {
 304                 return;
 305         }
 306
 307         count = object->common.reference_count;
 308         new_count = count;
 309
 310         /*
 311          * Perform the reference count action
 312          * (increment, decrement, or force delete)
 313          */
 314         switch (action) {
 315
 316         case REF_INCREMENT:
 317
 318                 new_count++;
 319                 object->common.reference_count = new_count;
 320
 321                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 322                                   "Obj %p Refs=%X, [Incremented]\n",
 323                                   object, new_count));
 324                 break;
 325
 326         case REF_DECREMENT:
 327
 328                 if (count < 1) {
 329                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 330                                           "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
 331                                           object, new_count));
 332
 333                         new_count = 0;
 334                 } else {
 335                         new_count--;
 336
 337                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 338                                           "Obj %p Refs=%X, [Decremented]\n",
 339                                           object, new_count));
 340                 }
 341
 342                 if (ACPI_GET_OBJECT_TYPE(object) == ACPI_TYPE_METHOD) {
 343                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 344                                           "Method Obj %p Refs=%X, [Decremented]\n",
 345                                           object, new_count));
 346                 }
 347
 348                 object->common.reference_count = new_count;
 349                 if (new_count == 0) {
 350                         acpi_ut_delete_internal_obj(object);
 351                 }
 352
 353                 break;
 354
 355         case REF_FORCE_DELETE:
 356
 357                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 358                                   "Obj %p Refs=%X, Force delete! (Set to 0)\n",
 359                                   object, count));
 360
 361                 new_count = 0;
 362                 object->common.reference_count = new_count;
 363                 acpi_ut_delete_internal_obj(object);
 364                 break;
 365
 366         default:
 367
 368                 ACPI_ERROR((AE_INFO, "Unknown action (%X)", action));
 369                 break;
 370         }
 371
 372         /*
 373          * Sanity check the reference count, for debug purposes only.
 374          * (A deleted object will have a huge reference count)
 375          */
 376         if (count > ACPI_MAX_REFERENCE_COUNT) {
 377
 378                 ACPI_WARNING((AE_INFO,
 379                               "Large Reference Count (%X) in object %p",
 380                               count, object));
 381         }
 382
 383         return;
 384 }
 385
 386 /*******************************************************************************
 387  *
 388  * FUNCTION:    acpi_ut_update_object_reference
 389  *
 390  * PARAMETERS:  Object              - Increment ref count for this object
 391  *                                    and all sub-objects
 392  *              Action              - Either REF_INCREMENT or REF_DECREMENT or
 393  *                                    REF_FORCE_DELETE
 394  *
 395  * RETURN:      Status
 396  *
 397  * DESCRIPTION: Increment the object reference count
 398  *
 399  * Object references are incremented when:
 400  * 1) An object is attached to a Node (namespace object)
 401  * 2) An object is copied (all subobjects must be incremented)
 402  *
 403  * Object references are decremented when:
 404  * 1) An object is detached from an Node
 405  *
 406  ******************************************************************************/
 407
 408 acpi_status
 409 acpi_ut_update_object_reference(union acpi_operand_object * object, u16 action)
 410 {
 411         acpi_status status = AE_OK;
 412         union acpi_generic_state *state_list = NULL;
 413         union acpi_operand_object *next_object = NULL;
 414         union acpi_generic_state *state;
 415         acpi_native_uint i;
 416
 417         ACPI_FUNCTION_TRACE_PTR("ut_update_object_reference", object);
 418
 419         while (object) {
 420
 421                 /* Make sure that this isn't a namespace handle */
 422
 423                 if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
 424                         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 425                                           "Object %p is NS handle\n", object));
 426                         return_ACPI_STATUS(AE_OK);
 427                 }
 428
 429                 /*
 430                  * All sub-objects must have their reference count incremented also.
 431                  * Different object types have different subobjects.
 432                  */
 433                 switch (ACPI_GET_OBJECT_TYPE(object)) {
 434                 case ACPI_TYPE_DEVICE:
 435
 436                         acpi_ut_update_ref_count(object->device.system_notify,
 437                                                  action);
 438                         acpi_ut_update_ref_count(object->device.device_notify,
 439                                                  action);
 440                         break;
 441
 442                 case ACPI_TYPE_PACKAGE:
 443                         /*
 444                          * We must update all the sub-objects of the package,
 445                          * each of whom may have their own sub-objects.
 446                          */
 447                         for (i = 0; i < object->package.count; i++) {
 448                                 /*
 449                                  * Push each element onto the stack for later processing.
 450                                  * Note: There can be null elements within the package,
 451                                  * these are simply ignored
 452                                  */
 453                                 status =
 454                                     acpi_ut_create_update_state_and_push
 455                                     (object->package.elements[i], action,
 456                                      &state_list);
 457                                 if (ACPI_FAILURE(status)) {
 458                                         goto error_exit;
 459                                 }
 460                         }
 461                         break;
 462
 463                 case ACPI_TYPE_BUFFER_FIELD:
 464
 465                         next_object = object->buffer_field.buffer_obj;
 466                         break;
 467
 468                 case ACPI_TYPE_LOCAL_REGION_FIELD:
 469
 470                         next_object = object->field.region_obj;
 471                         break;
 472
 473                 case ACPI_TYPE_LOCAL_BANK_FIELD:
 474
 475                         next_object = object->bank_field.bank_obj;
 476                         status =
 477                             acpi_ut_create_update_state_and_push(object->
 478                                                                  bank_field.
 479                                                                  region_obj,
 480                                                                  action,
 481                                                                  &state_list);
 482                         if (ACPI_FAILURE(status)) {
 483                                 goto error_exit;
 484                         }
 485                         break;
 486
 487                 case ACPI_TYPE_LOCAL_INDEX_FIELD:
 488
 489                         next_object = object->index_field.index_obj;
 490                         status =
 491                             acpi_ut_create_update_state_and_push(object->
 492                                                                  index_field.
 493                                                                  data_obj,
 494                                                                  action,
 495                                                                  &state_list);
 496                         if (ACPI_FAILURE(status)) {
 497                                 goto error_exit;
 498                         }
 499                         break;
 500
 501                 case ACPI_TYPE_LOCAL_REFERENCE:
 502                         /*
 503                          * The target of an Index (a package, string, or buffer) must track
 504                          * changes to the ref count of the index.
 505                          */
 506                         if (object->reference.opcode == AML_INDEX_OP) {
 507                                 next_object = object->reference.object;
 508                         }
 509                         break;
 510
 511                 case ACPI_TYPE_REGION:
 512                 default:
 513                         break;  /* No subobjects */
 514                 }
 515
 516                 /*
 517                  * Now we can update the count in the main object.  This can only
 518                  * happen after we update the sub-objects in case this causes the
 519                  * main object to be deleted.
 520                  */
 521                 acpi_ut_update_ref_count(object, action);
 522                 object = NULL;
 523
 524                 /* Move on to the next object to be updated */
 525
 526                 if (next_object) {
 527                         object = next_object;
 528                         next_object = NULL;
 529                 } else if (state_list) {
 530                         state = acpi_ut_pop_generic_state(&state_list);
 531                         object = state->update.object;
 532                         acpi_ut_delete_generic_state(state);
 533                 }
 534         }
 535
 536         return_ACPI_STATUS(AE_OK);
 537
 538       error_exit:
 539
 540         ACPI_EXCEPTION((AE_INFO, status,
 541                         "Could not update object reference count"));
 542
 543         return_ACPI_STATUS(status);
 544 }
 545
 546 /*******************************************************************************
 547  *
 548  * FUNCTION:    acpi_ut_add_reference
 549  *
 550  * PARAMETERS:  Object          - Object whose reference count is to be
 551  *                                incremented
 552  *
 553  * RETURN:      None
 554  *
 555  * DESCRIPTION: Add one reference to an ACPI object
 556  *
 557  ******************************************************************************/
 558
 559 void acpi_ut_add_reference(union acpi_operand_object *object)
 560 {
 561
 562         ACPI_FUNCTION_TRACE_PTR("ut_add_reference", object);
 563
 564         /* Ensure that we have a valid object */
 565
 566         if (!acpi_ut_valid_internal_object(object)) {
 567                 return_VOID;
 568         }
 569
 570         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 571                           "Obj %p Current Refs=%X [To Be Incremented]\n",
 572                           object, object->common.reference_count));
 573
 574         /* Increment the reference count */
 575
 576         (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
 577         return_VOID;
 578 }
 579
 580 /*******************************************************************************
 581  *
 582  * FUNCTION:    acpi_ut_remove_reference
 583  *
 584  * PARAMETERS:  Object         - Object whose ref count will be decremented
 585  *
 586  * RETURN:      None
 587  *
 588  * DESCRIPTION: Decrement the reference count of an ACPI internal object
 589  *
 590  ******************************************************************************/
 591
 592 void acpi_ut_remove_reference(union acpi_operand_object *object)
 593 {
 594
 595         ACPI_FUNCTION_TRACE_PTR("ut_remove_reference", object);
 596
 597         /*
 598          * Allow a NULL pointer to be passed in, just ignore it.  This saves
 599          * each caller from having to check.  Also, ignore NS nodes.
 600          *
 601          */
 602         if (!object ||
 603             (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
 604                 return_VOID;
 605         }
 606
 607         /* Ensure that we have a valid object */
 608
 609         if (!acpi_ut_valid_internal_object(object)) {
 610                 return_VOID;
 611         }
 612
 613         ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
 614                           "Obj %p Current Refs=%X [To Be Decremented]\n",
 615                           object, object->common.reference_count));
 616
 617         /*
 618          * Decrement the reference count, and only actually delete the object
 619          * if the reference count becomes 0.  (Must also decrement the ref count
 620          * of all subobjects!)
 621          */
 622         (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
 623         return_VOID;
 624 }