/*******************************************************************************
 *
 * 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;
}