nsobject.c

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/*******************************************************************************
 *
 * Module Name: nsobject - Utilities for objects attached to namespace
 *                         table entries
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * 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 "accommon.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsobject")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_attach_object
 *
 * PARAMETERS:  node                - Parent Node
 *              object              - Object to be attached
 *              type                - Type of object, or ACPI_TYPE_ANY if not
 *                                    known
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Record the given object as the value associated with the
 *              name whose acpi_handle is passed.  If Object is NULL
 *              and Type is ACPI_TYPE_ANY, set the name as having no value.
 *              Note: Future may require that the Node->Flags field be passed
 *              as a parameter.
 *
 * MUTEX:       Assumes namespace is locked
 *
 ******************************************************************************/
acpi_status
acpi_ns_attach_object(struct acpi_namespace_node *node,
              union acpi_operand_object *object, acpi_object_type type)
{
    union acpi_operand_object *obj_desc;
    union acpi_operand_object *last_obj_desc;
    acpi_object_type object_type = ACPI_TYPE_ANY;

    ACPI_FUNCTION_TRACE(ns_attach_object);

    /*
     * Parameter validation
     */
    if (!node) {

        /* Invalid handle */

        ACPI_ERROR((AE_INFO, "Null NamedObj handle"));
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    if (!object && (ACPI_TYPE_ANY != type)) {

        /* Null object */

        ACPI_ERROR((AE_INFO,
                "Null object, but type not ACPI_TYPE_ANY"));
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    if (ACPI_GET_DESCRIPTOR_TYPE(node) != ACPI_DESC_TYPE_NAMED) {

        /* Not a name handle */

        ACPI_ERROR((AE_INFO, "Invalid handle %p [%s]",
                node, acpi_ut_get_descriptor_name(node)));
        return_ACPI_STATUS(AE_BAD_PARAMETER);
    }

    /* Check if this object is already attached */

    if (node->object == object) {
        ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                  "Obj %p already installed in NameObj %p\n",
                  object, node));

        return_ACPI_STATUS(AE_OK);
    }

    /* If null object, we will just install it */

    if (!object) {
        obj_desc = NULL;
        object_type = ACPI_TYPE_ANY;
    }

    /*
     * If the source object is a namespace Node with an attached object,
     * we will use that (attached) object
     */
    else if ((ACPI_GET_DESCRIPTOR_TYPE(object) == ACPI_DESC_TYPE_NAMED) &&
         ((struct acpi_namespace_node *)object)->object) {
        /*
         * Value passed is a name handle and that name has a
         * non-null value.  Use that name's value and type.
         */
        obj_desc = ((struct acpi_namespace_node *)object)->object;
        object_type = ((struct acpi_namespace_node *)object)->type;
    }

    /*
     * Otherwise, we will use the parameter object, but we must type
     * it first
     */
    else {
        obj_desc = (union acpi_operand_object *)object;

        /* Use the given type */

        object_type = type;
    }

    ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Installing %p into Node %p [%4.4s]\n",
              obj_desc, node, acpi_ut_get_node_name(node)));

    /* Detach an existing attached object if present */

    if (node->object) {
        acpi_ns_detach_object(node);
    }

    if (obj_desc) {
        /*
         * Must increment the new value's reference count
         * (if it is an internal object)
         */
        acpi_ut_add_reference(obj_desc);

        /*
         * Handle objects with multiple descriptors - walk
         * to the end of the descriptor list
         */
        last_obj_desc = obj_desc;
        while (last_obj_desc->common.next_object) {
            last_obj_desc = last_obj_desc->common.next_object;
        }

        /* Install the object at the front of the object list */

        last_obj_desc->common.next_object = node->object;
    }

    node->type = (u8) object_type;
    node->object = obj_desc;

    return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_detach_object
 *
 * PARAMETERS:  node           - A Namespace node whose object will be detached
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Detach/delete an object associated with a namespace node.
 *              if the object is an allocated object, it is freed.
 *              Otherwise, the field is simply cleared.
 *
 ******************************************************************************/

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

    ACPI_FUNCTION_TRACE(ns_detach_object);

    obj_desc = node->object;

    if (!obj_desc || (obj_desc->common.type == ACPI_TYPE_LOCAL_DATA)) {
        return_VOID;
    }

    if (node->flags & ANOBJ_ALLOCATED_BUFFER) {

        /* Free the dynamic aml buffer */

        if (obj_desc->common.type == ACPI_TYPE_METHOD) {
            ACPI_FREE(obj_desc->method.aml_start);
        }
    }

    /* Clear the entry in all cases */

    node->object = NULL;
    if (ACPI_GET_DESCRIPTOR_TYPE(obj_desc) == ACPI_DESC_TYPE_OPERAND) {
        node->object = obj_desc->common.next_object;
        if (node->object &&
            ((node->object)->common.type != ACPI_TYPE_LOCAL_DATA)) {
            node->object = node->object->common.next_object;
        }
    }

    /* Reset the node type to untyped */

    node->type = ACPI_TYPE_ANY;

    ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "Node %p [%4.4s] Object %p\n",
              node, acpi_ut_get_node_name(node), obj_desc));

    /* Remove one reference on the object (and all subobjects) */

    acpi_ut_remove_reference(obj_desc);
    return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_attached_object
 *
 * PARAMETERS:  node             - Namespace node
 *
 * RETURN:      Current value of the object field from the Node whose
 *              handle is passed
 *
 * DESCRIPTION: Obtain the object attached to a namespace node.
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ns_get_attached_object(struct
                               acpi_namespace_node
                               *node)
{
    ACPI_FUNCTION_TRACE_PTR(ns_get_attached_object, node);

    if (!node) {
        ACPI_WARNING((AE_INFO, "Null Node ptr"));
        return_PTR(NULL);
    }

    if (!node->object ||
        ((ACPI_GET_DESCRIPTOR_TYPE(node->object) != ACPI_DESC_TYPE_OPERAND)
         && (ACPI_GET_DESCRIPTOR_TYPE(node->object) !=
         ACPI_DESC_TYPE_NAMED))
        || ((node->object)->common.type == ACPI_TYPE_LOCAL_DATA)) {
        return_PTR(NULL);
    }

    return_PTR(node->object);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_secondary_object
 *
 * PARAMETERS:  node             - Namespace node
 *
 * RETURN:      Current value of the object field from the Node whose
 *              handle is passed.
 *
 * DESCRIPTION: Obtain a secondary object associated with a namespace node.
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ns_get_secondary_object(union
                            acpi_operand_object
                            *obj_desc)
{
    ACPI_FUNCTION_TRACE_PTR(ns_get_secondary_object, obj_desc);

    if ((!obj_desc) ||
        (obj_desc->common.type == ACPI_TYPE_LOCAL_DATA) ||
        (!obj_desc->common.next_object) ||
        ((obj_desc->common.next_object)->common.type ==
         ACPI_TYPE_LOCAL_DATA)) {
        return_PTR(NULL);
    }

    return_PTR(obj_desc->common.next_object);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_attach_data
 *
 * PARAMETERS:  node            - Namespace node
 *              handler         - Handler to be associated with the data
 *              data            - Data to be attached
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Low-level attach data.  Create and attach a Data object.
 *
 ******************************************************************************/

acpi_status
acpi_ns_attach_data(struct acpi_namespace_node *node,
            acpi_object_handler handler, void *data)
{
    union acpi_operand_object *prev_obj_desc;
    union acpi_operand_object *obj_desc;
    union acpi_operand_object *data_desc;

    /* We only allow one attachment per handler */

    prev_obj_desc = NULL;
    obj_desc = node->object;
    while (obj_desc) {
        if ((obj_desc->common.type == ACPI_TYPE_LOCAL_DATA) &&
            (obj_desc->data.handler == handler)) {
            return (AE_ALREADY_EXISTS);
        }

        prev_obj_desc = obj_desc;
        obj_desc = obj_desc->common.next_object;
    }

    /* Create an internal object for the data */

    data_desc = acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_DATA);
    if (!data_desc) {
        return (AE_NO_MEMORY);
    }

    data_desc->data.handler = handler;
    data_desc->data.pointer = data;

    /* Install the data object */

    if (prev_obj_desc) {
        prev_obj_desc->common.next_object = data_desc;
    } else {
        node->object = data_desc;
    }

    return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_detach_data
 *
 * PARAMETERS:  node            - Namespace node
 *              handler         - Handler associated with the data
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Low-level detach data.  Delete the data node, but the caller
 *              is responsible for the actual data.
 *
 ******************************************************************************/

acpi_status
acpi_ns_detach_data(struct acpi_namespace_node * node,
            acpi_object_handler handler)
{
    union acpi_operand_object *obj_desc;
    union acpi_operand_object *prev_obj_desc;

    prev_obj_desc = NULL;
    obj_desc = node->object;
    while (obj_desc) {
        if ((obj_desc->common.type == ACPI_TYPE_LOCAL_DATA) &&
            (obj_desc->data.handler == handler)) {
            if (prev_obj_desc) {
                prev_obj_desc->common.next_object =
                    obj_desc->common.next_object;
            } else {
                node->object = obj_desc->common.next_object;
            }

            acpi_ut_remove_reference(obj_desc);
            return (AE_OK);
        }

        prev_obj_desc = obj_desc;
        obj_desc = obj_desc->common.next_object;
    }

    return (AE_NOT_FOUND);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_attached_data
 *
 * PARAMETERS:  node            - Namespace node
 *              handler         - Handler associated with the data
 *              data            - Where the data is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Low level interface to obtain data previously associated with
 *              a namespace node.
 *
 ******************************************************************************/

acpi_status
acpi_ns_get_attached_data(struct acpi_namespace_node * node,
              acpi_object_handler handler, void **data)
{
    union acpi_operand_object *obj_desc;

    obj_desc = node->object;
    while (obj_desc) {
        if ((obj_desc->common.type == ACPI_TYPE_LOCAL_DATA) &&
            (obj_desc->data.handler == handler)) {
            *data = obj_desc->data.pointer;
            return (AE_OK);
        }

        obj_desc = obj_desc->common.next_object;
    }

    return (AE_NOT_FOUND);
}