// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
 *
 * Module Name: nsalloc - Namespace allocation and deletion utilities
 *
 ******************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsalloc")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_create_node
 *
 * PARAMETERS:  name            - Name of the new node (4 char ACPI name)
 *
 * RETURN:      New namespace node (Null on failure)
 *
 * DESCRIPTION: Create a namespace node
 *
 ******************************************************************************/
struct acpi_namespace_node *acpi_ns_create_node(u32 name)
{
        struct acpi_namespace_node *node;
#ifdef ACPI_DBG_TRACK_ALLOCATIONS
        u32 temp;
#endif

        ACPI_FUNCTION_TRACE(ns_create_node);

        node = acpi_os_acquire_object(acpi_gbl_namespace_cache);
        if (!node) {
                return_PTR(NULL);
        }

        ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_allocated++);

#ifdef ACPI_DBG_TRACK_ALLOCATIONS
        temp = acpi_gbl_ns_node_list->total_allocated -
            acpi_gbl_ns_node_list->total_freed;
        if (temp > acpi_gbl_ns_node_list->max_occupied) {
                acpi_gbl_ns_node_list->max_occupied = temp;
        }
#endif

        node->name.integer = name;
        ACPI_SET_DESCRIPTOR_TYPE(node, ACPI_DESC_TYPE_NAMED);
        return_PTR(node);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_node
 *
 * PARAMETERS:  node            - Node to be deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Delete a namespace node. All node deletions must come through
 *              here. Detaches any attached objects, including any attached
 *              data. If a handler is associated with attached data, it is
 *              invoked before the node is deleted.
 *
 ******************************************************************************/

void acpi_ns_delete_node(struct acpi_namespace_node *node)
{
        union acpi_operand_object *obj_desc;
        union acpi_operand_object *next_desc;

        ACPI_FUNCTION_NAME(ns_delete_node);

        if (!node) {
                return_VOID;
        }

        /* Detach an object if there is one */

        acpi_ns_detach_object(node);

        /*
         * Delete an attached data object list if present (objects that were
         * attached via acpi_attach_data). Note: After any normal object is
         * detached above, the only possible remaining object(s) are data
         * objects, in a linked list.
         */
        obj_desc = node->object;
        while (obj_desc && (obj_desc->common.type == ACPI_TYPE_LOCAL_DATA)) {

                /* Invoke the attached data deletion handler if present */

                if (obj_desc->data.handler) {
                        obj_desc->data.handler(node, obj_desc->data.pointer);
                }

                next_desc = obj_desc->common.next_object;
                acpi_ut_remove_reference(obj_desc);
                obj_desc = next_desc;
        }

        /* Special case for the statically allocated root node */

        if (node == acpi_gbl_root_node) {
                return;
        }

        /* Now we can delete the node */

        (void)acpi_os_release_object(acpi_gbl_namespace_cache, node);

        ACPI_MEM_TRACKING(acpi_gbl_ns_node_list->total_freed++);
        ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Node %p, Remaining %X\n",
                          node, acpi_gbl_current_node_count));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_remove_node
 *
 * PARAMETERS:  node            - Node to be removed/deleted
 *
 * RETURN:      None
 *
 * DESCRIPTION: Remove (unlink) and delete a namespace node
 *
 ******************************************************************************/

void acpi_ns_remove_node(struct acpi_namespace_node *node)
{
        struct acpi_namespace_node *parent_node;
        struct acpi_namespace_node *prev_node;
        struct acpi_namespace_node *next_node;

        ACPI_FUNCTION_TRACE_PTR(ns_remove_node, node);

        parent_node = node->parent;

        prev_node = NULL;
        next_node = parent_node->child;

        /* Find the node that is the previous peer in the parent's child list */

        while (next_node != node) {
                prev_node = next_node;
                next_node = next_node->peer;
        }

        if (prev_node) {

                /* Node is not first child, unlink it */

                prev_node->peer = node->peer;
        } else {
                /*
                 * Node is first child (has no previous peer).
                 * Link peer list to parent
                 */
                parent_node->child = node->peer;
        }

        /* Delete the node and any attached objects */

        acpi_ns_delete_node(node);
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_install_node
 *
 * PARAMETERS:  walk_state      - Current state of the walk
 *              parent_node     - The parent of the new Node
 *              node            - The new Node to install
 *              type            - ACPI object type of the new Node
 *
 * RETURN:      None
 *
 * DESCRIPTION: Initialize a new namespace node and install it amongst
 *              its peers.
 *
 *              Note: Current namespace lookup is linear search. This appears
 *              to be sufficient as namespace searches consume only a small
 *              fraction of the execution time of the ACPI subsystem.
 *
 ******************************************************************************/

void acpi_ns_install_node(struct acpi_walk_state *walk_state, struct acpi_namespace_node *parent_node,  /* Parent */
                          struct acpi_namespace_node *node,     /* New Child */
                          acpi_object_type type)
{
        acpi_owner_id owner_id = 0;
        struct acpi_namespace_node *child_node;

        ACPI_FUNCTION_TRACE(ns_install_node);

        if (walk_state) {
                /*
                 * Get the owner ID from the Walk state. The owner ID is used to
                 * track table deletion and deletion of objects created by methods.
                 */
                owner_id = walk_state->owner_id;

                if ((walk_state->method_desc) &&
                    (parent_node != walk_state->method_node)) {
                        /*
                         * A method is creating a new node that is not a child of the
                         * method (it is non-local). Mark the executing method as having
                         * modified the namespace. This is used for cleanup when the
                         * method exits.
                         */
                        walk_state->method_desc->method.info_flags |=
                            ACPI_METHOD_MODIFIED_NAMESPACE;
                }
        }

        /* Link the new entry into the parent and existing children */

        node->peer = NULL;
        node->parent = parent_node;
        child_node = parent_node->child;

        if (!child_node) {
                parent_node->child = node;
        } else {
                /* Add node to the end of the peer list */

                while (child_node->peer) {
                        child_node = child_node->peer;
                }

                child_node->peer = node;
        }

        /* Init the new entry */

        node->owner_id = owner_id;
        node->type = (u8) type;

        ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
                          "%4.4s (%s) [Node %p Owner %3.3X] added to %4.4s (%s) [Node %p]\n",
                          acpi_ut_get_node_name(node),
                          acpi_ut_get_type_name(node->type), node, owner_id,
                          acpi_ut_get_node_name(parent_node),
                          acpi_ut_get_type_name(parent_node->type),
                          parent_node));

        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_children
 *
 * PARAMETERS:  parent_node     - Delete this objects children
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Delete all children of the parent object. In other words,
 *              deletes a "scope".
 *
 ******************************************************************************/

void acpi_ns_delete_children(struct acpi_namespace_node *parent_node)
{
        struct acpi_namespace_node *next_node;
        struct acpi_namespace_node *node_to_delete;

        ACPI_FUNCTION_TRACE_PTR(ns_delete_children, parent_node);

        if (!parent_node) {
                return_VOID;
        }

        /* Deallocate all children at this level */

        next_node = parent_node->child;
        while (next_node) {

                /* Grandchildren should have all been deleted already */

                if (next_node->child) {
                        ACPI_ERROR((AE_INFO, "Found a grandchild! P=%p C=%p",
                                    parent_node, next_node));
                }

                /*
                 * Delete this child node and move on to the next child in the list.
                 * No need to unlink the node since we are deleting the entire branch.
                 */
                node_to_delete = next_node;
                next_node = next_node->peer;
                acpi_ns_delete_node(node_to_delete);
        };

        /* Clear the parent's child pointer */

        parent_node->child = NULL;
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_namespace_subtree
 *
 * PARAMETERS:  parent_node     - Root of the subtree to be deleted
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Delete a subtree of the namespace. This includes all objects
 *              stored within the subtree.
 *
 ******************************************************************************/

void acpi_ns_delete_namespace_subtree(struct acpi_namespace_node *parent_node)
{
        struct acpi_namespace_node *child_node = NULL;
        u32 level = 1;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ns_delete_namespace_subtree);

        if (!parent_node) {
                return_VOID;
        }

        /* Lock namespace for possible update */

        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
        if (ACPI_FAILURE(status)) {
                return_VOID;
        }

        /*
         * Traverse the tree of objects until we bubble back up
         * to where we started.
         */
        while (level > 0) {

                /* Get the next node in this scope (NULL if none) */

                child_node = acpi_ns_get_next_node(parent_node, child_node);
                if (child_node) {

                        /* Found a child node - detach any attached object */

                        acpi_ns_detach_object(child_node);

                        /* Check if this node has any children */

                        if (child_node->child) {
                                /*
                                 * There is at least one child of this node,
                                 * visit the node
                                 */
                                level++;
                                parent_node = child_node;
                                child_node = NULL;
                        }
                } else {
                        /*
                         * No more children of this parent node.
                         * Move up to the grandparent.
                         */
                        level--;

                        /*
                         * Now delete all of the children of this parent
                         * all at the same time.
                         */
                        acpi_ns_delete_children(parent_node);

                        /* New "last child" is this parent node */

                        child_node = parent_node;

                        /* Move up the tree to the grandparent */

                        parent_node = parent_node->parent;
                }
        }

        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_delete_namespace_by_owner
 *
 * PARAMETERS:  owner_id    - All nodes with this owner will be deleted
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Delete entries within the namespace that are owned by a
 *              specific ID. Used to delete entire ACPI tables. All
 *              reference counts are updated.
 *
 * MUTEX:       Locks namespace during deletion walk.
 *
 ******************************************************************************/

void acpi_ns_delete_namespace_by_owner(acpi_owner_id owner_id)
{
        struct acpi_namespace_node *child_node;
        struct acpi_namespace_node *deletion_node;
        struct acpi_namespace_node *parent_node;
        u32 level;
        acpi_status status;

        ACPI_FUNCTION_TRACE_U32(ns_delete_namespace_by_owner, owner_id);

        if (owner_id == 0) {
                return_VOID;
        }

        /* Lock namespace for possible update */

        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
        if (ACPI_FAILURE(status)) {
                return_VOID;
        }

        deletion_node = NULL;
        parent_node = acpi_gbl_root_node;
        child_node = NULL;
        level = 1;

        /*
         * Traverse the tree of nodes until we bubble back up
         * to where we started.
         */
        while (level > 0) {
                /*
                 * Get the next child of this parent node. When child_node is NULL,
                 * the first child of the parent is returned
                 */
                child_node = acpi_ns_get_next_node(parent_node, child_node);

                if (deletion_node) {
                        acpi_ns_delete_children(deletion_node);
                        acpi_ns_remove_node(deletion_node);
                        deletion_node = NULL;
                }

                if (child_node) {
                        if (child_node->owner_id == owner_id) {

                                /* Found a matching child node - detach any attached object */

                                acpi_ns_detach_object(child_node);
                        }

                        /* Check if this node has any children */

                        if (child_node->child) {
                                /*
                                 * There is at least one child of this node,
                                 * visit the node
                                 */
                                level++;
                                parent_node = child_node;
                                child_node = NULL;
                        } else if (child_node->owner_id == owner_id) {
                                deletion_node = child_node;
                        }
                } else {
                        /*
                         * No more children of this parent node.
                         * Move up to the grandparent.
                         */
                        level--;
                        if (level != 0) {
                                if (parent_node->owner_id == owner_id) {
                                        deletion_node = parent_node;
                                }
                        }

                        /* New "last child" is this parent node */

                        child_node = parent_node;

                        /* Move up the tree to the grandparent */

                        parent_node = parent_node->parent;
                }
        }

        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
        return_VOID;
}