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utdelete.c

/*******************************************************************************
 *
 * Module Name: utdelete - object deletion and reference count utilities
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/acinterp.h>
#include <acpi/acnamesp.h>
#include <acpi/acevents.h>
#include <acpi/amlcode.h>

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utdelete")

/* Local prototypes */
static void acpi_ut_delete_internal_obj(union acpi_operand_object *object);

static void
acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_internal_obj
 *
 * PARAMETERS:  Object         - Object to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Low level object deletion, after reference counts have been
 *              updated (All reference counts, including sub-objects!)
 *
 ******************************************************************************/

static void acpi_ut_delete_internal_obj(union acpi_operand_object *object)
{
      void *obj_pointer = NULL;
      union acpi_operand_object *handler_desc;
      union acpi_operand_object *second_desc;
      union acpi_operand_object *next_desc;

      ACPI_FUNCTION_TRACE_PTR(ut_delete_internal_obj, object);

      if (!object) {
            return_VOID;
      }

      /*
       * Must delete or free any pointers within the object that are not
       * actual ACPI objects (for example, a raw buffer pointer).
       */
      switch (ACPI_GET_OBJECT_TYPE(object)) {
      case ACPI_TYPE_STRING:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "**** String %p, ptr %p\n", object,
                          object->string.pointer));

            /* Free the actual string buffer */

            if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {

                  /* But only if it is NOT a pointer into an ACPI table */

                  obj_pointer = object->string.pointer;
            }
            break;

      case ACPI_TYPE_BUFFER:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "**** Buffer %p, ptr %p\n", object,
                          object->buffer.pointer));

            /* Free the actual buffer */

            if (!(object->common.flags & AOPOBJ_STATIC_POINTER)) {

                  /* But only if it is NOT a pointer into an ACPI table */

                  obj_pointer = object->buffer.pointer;
            }
            break;

      case ACPI_TYPE_PACKAGE:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          " **** Package of count %X\n",
                          object->package.count));

            /*
             * Elements of the package are not handled here, they are deleted
             * separately
             */

            /* Free the (variable length) element pointer array */

            obj_pointer = object->package.elements;
            break;

      case ACPI_TYPE_DEVICE:

            if (object->device.gpe_block) {
                  (void)acpi_ev_delete_gpe_block(object->device.
                                           gpe_block);
            }

            /* Walk the handler list for this device */

            handler_desc = object->device.handler;
            while (handler_desc) {
                  next_desc = handler_desc->address_space.next;
                  acpi_ut_remove_reference(handler_desc);
                  handler_desc = next_desc;
            }
            break;

      case ACPI_TYPE_MUTEX:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "***** Mutex %p, OS Mutex %p\n",
                          object, object->mutex.os_mutex));

            if (object->mutex.os_mutex == acpi_gbl_global_lock_mutex) {

                  /* Global Lock has extra semaphore */

                  (void)
                      acpi_os_delete_semaphore
                      (acpi_gbl_global_lock_semaphore);
                  acpi_gbl_global_lock_semaphore = NULL;

                  acpi_os_delete_mutex(object->mutex.os_mutex);
                  acpi_gbl_global_lock_mutex = NULL;
            } else {
                  acpi_ex_unlink_mutex(object);
                  acpi_os_delete_mutex(object->mutex.os_mutex);
            }
            break;

      case ACPI_TYPE_EVENT:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "***** Event %p, OS Semaphore %p\n",
                          object, object->event.os_semaphore));

            (void)acpi_os_delete_semaphore(object->event.os_semaphore);
            object->event.os_semaphore = NULL;
            break;

      case ACPI_TYPE_METHOD:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "***** Method %p\n", object));

            /* Delete the method mutex if it exists */

            if (object->method.mutex) {
                  acpi_os_delete_mutex(object->method.mutex->mutex.
                                   os_mutex);
                  acpi_ut_delete_object_desc(object->method.mutex);
                  object->method.mutex = NULL;
            }
            break;

      case ACPI_TYPE_REGION:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "***** Region %p\n", object));

            second_desc = acpi_ns_get_secondary_object(object);
            if (second_desc) {
                  /*
                   * Free the region_context if and only if the handler is one of the
                   * default handlers -- and therefore, we created the context object
                   * locally, it was not created by an external caller.
                   */
                  handler_desc = object->region.handler;
                  if (handler_desc) {
                        if (handler_desc->address_space.handler_flags &
                            ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {

                              /* Deactivate region and free region context */

                              if (handler_desc->address_space.setup) {
                                    (void)handler_desc->
                                        address_space.setup(object,
                                                      ACPI_REGION_DEACTIVATE,
                                                      handler_desc->
                                                      address_space.
                                                      context,
                                                      &second_desc->
                                                      extra.
                                                      region_context);
                              }
                        }

                        acpi_ut_remove_reference(handler_desc);
                  }

                  /* Now we can free the Extra object */

                  acpi_ut_delete_object_desc(second_desc);
            }
            break;

      case ACPI_TYPE_BUFFER_FIELD:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "***** Buffer Field %p\n", object));

            second_desc = acpi_ns_get_secondary_object(object);
            if (second_desc) {
                  acpi_ut_delete_object_desc(second_desc);
            }
            break;

      default:
            break;
      }

      /* Free any allocated memory (pointer within the object) found above */

      if (obj_pointer) {
            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "Deleting Object Subptr %p\n", obj_pointer));
            ACPI_FREE(obj_pointer);
      }

      /* Now the object can be safely deleted */

      ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Deleting Object %p [%s]\n",
                    object, acpi_ut_get_object_type_name(object)));

      acpi_ut_delete_object_desc(object);
      return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_internal_object_list
 *
 * PARAMETERS:  obj_list        - Pointer to the list to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: This function deletes an internal object list, including both
 *              simple objects and package objects
 *
 ******************************************************************************/

void acpi_ut_delete_internal_object_list(union acpi_operand_object **obj_list)
{
      union acpi_operand_object **internal_obj;

      ACPI_FUNCTION_TRACE(ut_delete_internal_object_list);

      /* Walk the null-terminated internal list */

      for (internal_obj = obj_list; *internal_obj; internal_obj++) {
            acpi_ut_remove_reference(*internal_obj);
      }

      /* Free the combined parameter pointer list and object array */

      ACPI_FREE(obj_list);
      return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_ref_count
 *
 * PARAMETERS:  Object          - Object whose ref count is to be updated
 *              Action          - What to do
 *
 * RETURN:      New ref count
 *
 * DESCRIPTION: Modify the ref count and return it.
 *
 ******************************************************************************/

static void
acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
{
      u16 count;
      u16 new_count;

      ACPI_FUNCTION_NAME(ut_update_ref_count);

      if (!object) {
            return;
      }

      count = object->common.reference_count;
      new_count = count;

      /*
       * Perform the reference count action (increment, decrement, force delete)
       */
      switch (action) {
      case REF_INCREMENT:

            new_count++;
            object->common.reference_count = new_count;

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "Obj %p Refs=%X, [Incremented]\n",
                          object, new_count));
            break;

      case REF_DECREMENT:

            if (count < 1) {
                  ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                                "Obj %p Refs=%X, can't decrement! (Set to 0)\n",
                                object, new_count));

                  new_count = 0;
            } else {
                  new_count--;

                  ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                                "Obj %p Refs=%X, [Decremented]\n",
                                object, new_count));
            }

            if (ACPI_GET_OBJECT_TYPE(object) == ACPI_TYPE_METHOD) {
                  ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                                "Method Obj %p Refs=%X, [Decremented]\n",
                                object, new_count));
            }

            object->common.reference_count = new_count;
            if (new_count == 0) {
                  acpi_ut_delete_internal_obj(object);
            }
            break;

      case REF_FORCE_DELETE:

            ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                          "Obj %p Refs=%X, Force delete! (Set to 0)\n",
                          object, count));

            new_count = 0;
            object->common.reference_count = new_count;
            acpi_ut_delete_internal_obj(object);
            break;

      default:

            ACPI_ERROR((AE_INFO, "Unknown action (%X)", action));
            break;
      }

      /*
       * Sanity check the reference count, for debug purposes only.
       * (A deleted object will have a huge reference count)
       */
      if (count > ACPI_MAX_REFERENCE_COUNT) {
            ACPI_WARNING((AE_INFO,
                        "Large Reference Count (%X) in object %p", count,
                        object));
      }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_object_reference
 *
 * PARAMETERS:  Object              - Increment ref count for this object
 *                                    and all sub-objects
 *              Action              - Either REF_INCREMENT or REF_DECREMENT or
 *                                    REF_FORCE_DELETE
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Increment the object reference count
 *
 * Object references are incremented when:
 * 1) An object is attached to a Node (namespace object)
 * 2) An object is copied (all subobjects must be incremented)
 *
 * Object references are decremented when:
 * 1) An object is detached from an Node
 *
 ******************************************************************************/

acpi_status
acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action)
{
      acpi_status status = AE_OK;
      union acpi_generic_state *state_list = NULL;
      union acpi_operand_object *next_object = NULL;
      union acpi_generic_state *state;
      acpi_native_uint i;

      ACPI_FUNCTION_TRACE_PTR(ut_update_object_reference, object);

      while (object) {

            /* Make sure that this isn't a namespace handle */

            if (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) {
                  ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                                "Object %p is NS handle\n", object));
                  return_ACPI_STATUS(AE_OK);
            }

            /*
             * All sub-objects must have their reference count incremented also.
             * Different object types have different subobjects.
             */
            switch (ACPI_GET_OBJECT_TYPE(object)) {
            case ACPI_TYPE_DEVICE:
            case ACPI_TYPE_PROCESSOR:
            case ACPI_TYPE_POWER:
            case ACPI_TYPE_THERMAL:

                  /* Update the notify objects for these types (if present) */

                  acpi_ut_update_ref_count(object->common_notify.
                                     system_notify, action);
                  acpi_ut_update_ref_count(object->common_notify.
                                     device_notify, action);
                  break;

            case ACPI_TYPE_PACKAGE:
                  /*
                   * We must update all the sub-objects of the package,
                   * each of whom may have their own sub-objects.
                   */
                  for (i = 0; i < object->package.count; i++) {
                        /*
                         * Push each element onto the stack for later processing.
                         * Note: There can be null elements within the package,
                         * these are simply ignored
                         */
                        status =
                            acpi_ut_create_update_state_and_push
                            (object->package.elements[i], action,
                             &state_list);
                        if (ACPI_FAILURE(status)) {
                              goto error_exit;
                        }
                  }
                  break;

            case ACPI_TYPE_BUFFER_FIELD:

                  next_object = object->buffer_field.buffer_obj;
                  break;

            case ACPI_TYPE_LOCAL_REGION_FIELD:

                  next_object = object->field.region_obj;
                  break;

            case ACPI_TYPE_LOCAL_BANK_FIELD:

                  next_object = object->bank_field.bank_obj;
                  status =
                      acpi_ut_create_update_state_and_push(object->
                                                 bank_field.
                                                 region_obj,
                                                 action,
                                                 &state_list);
                  if (ACPI_FAILURE(status)) {
                        goto error_exit;
                  }
                  break;

            case ACPI_TYPE_LOCAL_INDEX_FIELD:

                  next_object = object->index_field.index_obj;
                  status =
                      acpi_ut_create_update_state_and_push(object->
                                                 index_field.
                                                 data_obj,
                                                 action,
                                                 &state_list);
                  if (ACPI_FAILURE(status)) {
                        goto error_exit;
                  }
                  break;

            case ACPI_TYPE_LOCAL_REFERENCE:
                  /*
                   * The target of an Index (a package, string, or buffer) must track
                   * changes to the ref count of the index.
                   */
                  if (object->reference.opcode == AML_INDEX_OP) {
                        next_object = object->reference.object;
                  }
                  break;

            case ACPI_TYPE_REGION:
            default:
                  break;      /* No subobjects for all other types */
            }

            /*
             * Now we can update the count in the main object. This can only
             * happen after we update the sub-objects in case this causes the
             * main object to be deleted.
             */
            acpi_ut_update_ref_count(object, action);
            object = NULL;

            /* Move on to the next object to be updated */

            if (next_object) {
                  object = next_object;
                  next_object = NULL;
            } else if (state_list) {
                  state = acpi_ut_pop_generic_state(&state_list);
                  object = state->update.object;
                  acpi_ut_delete_generic_state(state);
            }
      }

      return_ACPI_STATUS(AE_OK);

      error_exit:

      ACPI_EXCEPTION((AE_INFO, status,
                  "Could not update object reference count"));

      return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_add_reference
 *
 * PARAMETERS:  Object          - Object whose reference count is to be
 *                                incremented
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add one reference to an ACPI object
 *
 ******************************************************************************/

void acpi_ut_add_reference(union acpi_operand_object *object)
{

      ACPI_FUNCTION_TRACE_PTR(ut_add_reference, object);

      /* Ensure that we have a valid object */

      if (!acpi_ut_valid_internal_object(object)) {
            return_VOID;
      }

      ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                    "Obj %p Current Refs=%X [To Be Incremented]\n",
                    object, object->common.reference_count));

      /* Increment the reference count */

      (void)acpi_ut_update_object_reference(object, REF_INCREMENT);
      return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_remove_reference
 *
 * PARAMETERS:  Object         - Object whose ref count will be decremented
 *
 * RETURN:      None
 *
 * DESCRIPTION: Decrement the reference count of an ACPI internal object
 *
 ******************************************************************************/

void acpi_ut_remove_reference(union acpi_operand_object *object)
{

      ACPI_FUNCTION_TRACE_PTR(ut_remove_reference, object);

      /*
       * Allow a NULL pointer to be passed in, just ignore it. This saves
       * each caller from having to check. Also, ignore NS nodes.
       *
       */
      if (!object ||
          (ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED)) {
            return_VOID;
      }

      /* Ensure that we have a valid object */

      if (!acpi_ut_valid_internal_object(object)) {
            return_VOID;
      }

      ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                    "Obj %p Current Refs=%X [To Be Decremented]\n",
                    object, object->common.reference_count));

      /*
       * Decrement the reference count, and only actually delete the object
       * if the reference count becomes 0. (Must also decrement the ref count
       * of all subobjects!)
       */
      (void)acpi_ut_update_object_reference(object, REF_DECREMENT);
      return_VOID;
}

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