// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
 *
 * Module Name: utdelete - object deletion and reference count utilities
 *
 ******************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "acevents.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;
        union acpi_operand_object *start_desc;
        union acpi_operand_object **last_obj_ptr;

        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 (object->common.type) {
        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;

                /*
                 * These objects have a possible list of notify handlers.
                 * Device object also may have a GPE block.
                 */
        case ACPI_TYPE_DEVICE:

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

                /*lint -fallthrough */

        case ACPI_TYPE_PROCESSOR:
        case ACPI_TYPE_THERMAL:

                /* Walk the address handler list for this object */

                handler_desc = object->common_notify.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 == 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;
                }

                if (object->method.node) {
                        object->method.node = NULL;
                }
                break;

        case ACPI_TYPE_REGION:

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

                /*
                 * Update address_range list. However, only permanent regions
                 * are installed in this list. (Not created within a method)
                 */
                if (!(object->region.node->flags & ANOBJ_TEMPORARY)) {
                        acpi_ut_remove_address_range(object->region.space_id,
                                                     object->region.node);
                }

                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) {
                                next_desc =
                                    handler_desc->address_space.region_list;
                                start_desc = next_desc;
                                last_obj_ptr =
                                    &handler_desc->address_space.region_list;

                                /* Remove the region object from the handler list */

                                while (next_desc) {
                                        if (next_desc == object) {
                                                *last_obj_ptr =
                                                    next_desc->region.next;
                                                break;
                                        }

                                        /* Walk the linked list of handlers */

                                        last_obj_ptr = &next_desc->region.next;
                                        next_desc = next_desc->region.next;

                                        /* Prevent infinite loop if list is corrupted */

                                        if (next_desc == start_desc) {
                                                ACPI_ERROR((AE_INFO,
                                                            "Circular region list in address handler object %p",
                                                            handler_desc));
                                                return_VOID;
                                        }
                                }

                                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;

        case ACPI_TYPE_LOCAL_BANK_FIELD:

                ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                                  "***** Bank 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_RAW((ACPI_DB_ALLOCATIONS,
                              "%s: Deleting Object %p [%s]\n",
                              ACPI_GET_FUNCTION_NAME, 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_ENTRY();

        /* 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;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_update_ref_count
 *
 * PARAMETERS:  object          - Object whose ref count is to be updated
 *              action          - What to do (REF_INCREMENT or REF_DECREMENT)
 *
 * RETURN:      None. Sets new reference count within the object
 *
 * DESCRIPTION: Modify the reference count for an internal acpi object
 *
 ******************************************************************************/

static void
acpi_ut_update_ref_count(union acpi_operand_object *object, u32 action)
{
        u16 original_count;
        u16 new_count = 0;
        acpi_cpu_flags lock_flags;

        ACPI_FUNCTION_NAME(ut_update_ref_count);

        if (!object) {
                return;
        }

        /*
         * Always get the reference count lock. Note: Interpreter and/or
         * Namespace is not always locked when this function is called.
         */
        lock_flags = acpi_os_acquire_lock(acpi_gbl_reference_count_lock);
        original_count = object->common.reference_count;

        /* Perform the reference count action (increment, decrement) */

        switch (action) {
        case REF_INCREMENT:

                new_count = original_count + 1;
                object->common.reference_count = new_count;
                acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);

                /* The current reference count should never be zero here */

                if (!original_count) {
                        ACPI_WARNING((AE_INFO,
                                      "Obj %p, Reference Count was zero before increment\n",
                                      object));
                }

                ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS,
                                  "Obj %p Type %.2X [%s] Refs %.2X [Incremented]\n",
                                  object, object->common.type,
                                  acpi_ut_get_object_type_name(object),
                                  new_count));
                break;

        case REF_DECREMENT:

                /* The current reference count must be non-zero */

                if (original_count) {
                        new_count = original_count - 1;
                        object->common.reference_count = new_count;
                }

                acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);

                if (!original_count) {
                        ACPI_WARNING((AE_INFO,
                                      "Obj %p, Reference Count is already zero, cannot decrement\n",
                                      object));
                }

                ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
                                      "%s: Obj %p Type %.2X Refs %.2X [Decremented]\n",
                                      ACPI_GET_FUNCTION_NAME, object,
                                      object->common.type, new_count));

                /* Actually delete the object on a reference count of zero */

                if (new_count == 0) {
                        acpi_ut_delete_internal_obj(object);
                }
                break;

        default:

                acpi_os_release_lock(acpi_gbl_reference_count_lock, lock_flags);
                ACPI_ERROR((AE_INFO, "Unknown Reference Count action (0x%X)",
                            action));
                return;
        }

        /*
         * Sanity check the reference count, for debug purposes only.
         * (A deleted object will have a huge reference count)
         */
        if (new_count > ACPI_MAX_REFERENCE_COUNT) {
                ACPI_WARNING((AE_INFO,
                              "Large Reference Count (0x%X) in object %p, Type=0x%.2X",
                              new_count, object, object->common.type));
        }
}

/*******************************************************************************
 *
 * 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
 *
 * 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_operand_object *prev_object;
        union acpi_generic_state *state;
        u32 i;

        ACPI_FUNCTION_NAME(ut_update_object_reference);

        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 (AE_OK);
                }

                /*
                 * All sub-objects must have their reference count incremented
                 * also. Different object types have different subobjects.
                 */
                switch (object->common.type) {
                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)
                         * Two lists, system and device notify handlers.
                         */
                        for (i = 0; i < ACPI_NUM_NOTIFY_TYPES; i++) {
                                prev_object =
                                    object->common_notify.notify_list[i];
                                while (prev_object) {
                                        next_object =
                                            prev_object->notify.next[i];
                                        acpi_ut_update_ref_count(prev_object,
                                                                 action);
                                        prev_object = next_object;
                                }
                        }
                        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++) {
                                /*
                                 * Null package elements are legal and can be simply
                                 * ignored.
                                 */
                                next_object = object->package.elements[i];
                                if (!next_object) {
                                        continue;
                                }

                                switch (next_object->common.type) {
                                case ACPI_TYPE_INTEGER:
                                case ACPI_TYPE_STRING:
                                case ACPI_TYPE_BUFFER:
                                        /*
                                         * For these very simple sub-objects, we can just
                                         * update the reference count here and continue.
                                         * Greatly increases performance of this operation.
                                         */
                                        acpi_ut_update_ref_count(next_object,
                                                                 action);
                                        break;

                                default:
                                        /*
                                         * For complex sub-objects, push them onto the stack
                                         * for later processing (this eliminates recursion.)
                                         */
                                        status =
                                            acpi_ut_create_update_state_and_push
                                            (next_object, action, &state_list);
                                        if (ACPI_FAILURE(status)) {
                                                goto error_exit;
                                        }
                                        break;
                                }
                        }
                        next_object = NULL;
                        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) or a named
                         * reference must track changes to the ref count of the index or
                         * target object.
                         */
                        if ((object->reference.class == ACPI_REFCLASS_INDEX) ||
                            (object->reference.class == ACPI_REFCLASS_NAME)) {
                                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 (AE_OK);

error_exit:

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

        /* Free any stacked Update State objects */

        while (state_list) {
                state = acpi_ut_pop_generic_state(&state_list);
                acpi_ut_delete_generic_state(state);
        }

        return (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_NAME(ut_add_reference);

        /* Ensure that we have a valid object */

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

        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;
}

/*******************************************************************************
 *
 * 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_NAME(ut_remove_reference);

        /*
         * 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;
        }

        /* Ensure that we have a valid object */

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

        ACPI_DEBUG_PRINT_RAW((ACPI_DB_ALLOCATIONS,
                              "%s: Obj %p Current Refs=%X [To Be Decremented]\n",
                              ACPI_GET_FUNCTION_NAME, 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;
}