/******************************************************************************
 *
 * Module Name: evregion - ACPI address_space (op_region) handler dispatch
 *
 *****************************************************************************/

/*
 * 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 "acevents.h"
#include "acnamesp.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evregion")

/* Local prototypes */
static u8
acpi_ev_has_default_handler(struct acpi_namespace_node *node,
                            acpi_adr_space_type space_id);

static void acpi_ev_orphan_ec_reg_method(void);

static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
                u32 level, void *context, void **return_value);

static acpi_status
acpi_ev_install_handler(acpi_handle obj_handle,
                        u32 level, void *context, void **return_value);

/* These are the address spaces that will get default handlers */

#define ACPI_NUM_DEFAULT_SPACES     4

static u8 acpi_gbl_default_address_spaces[ACPI_NUM_DEFAULT_SPACES] = {
        ACPI_ADR_SPACE_SYSTEM_MEMORY,
        ACPI_ADR_SPACE_SYSTEM_IO,
        ACPI_ADR_SPACE_PCI_CONFIG,
        ACPI_ADR_SPACE_DATA_TABLE
};

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_install_region_handlers
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Installs the core subsystem default address space handlers.
 *
 ******************************************************************************/

acpi_status acpi_ev_install_region_handlers(void)
{
        acpi_status status;
        u32 i;

        ACPI_FUNCTION_TRACE(ev_install_region_handlers);

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

        /*
         * All address spaces (PCI Config, EC, SMBus) are scope dependent and
         * registration must occur for a specific device.
         *
         * In the case of the system memory and IO address spaces there is
         * currently no device associated with the address space. For these we
         * use the root.
         *
         * We install the default PCI config space handler at the root so that
         * this space is immediately available even though the we have not
         * enumerated all the PCI Root Buses yet. This is to conform to the ACPI
         * specification which states that the PCI config space must be always
         * available -- even though we are nowhere near ready to find the PCI root
         * buses at this point.
         *
         * NOTE: We ignore AE_ALREADY_EXISTS because this means that a handler
         * has already been installed (via acpi_install_address_space_handler).
         * Similar for AE_SAME_HANDLER.
         */
        for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
                status = acpi_ev_install_space_handler(acpi_gbl_root_node,
                                                       acpi_gbl_default_address_spaces
                                                       [i],
                                                       ACPI_DEFAULT_HANDLER,
                                                       NULL, NULL);
                switch (status) {
                case AE_OK:
                case AE_SAME_HANDLER:
                case AE_ALREADY_EXISTS:

                        /* These exceptions are all OK */

                        status = AE_OK;
                        break;

                default:

                        goto unlock_and_exit;
                }
        }

      unlock_and_exit:
        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_has_default_handler
 *
 * PARAMETERS:  node                - Namespace node for the device
 *              space_id            - The address space ID
 *
 * RETURN:      TRUE if default handler is installed, FALSE otherwise
 *
 * DESCRIPTION: Check if the default handler is installed for the requested
 *              space ID.
 *
 ******************************************************************************/

static u8
acpi_ev_has_default_handler(struct acpi_namespace_node *node,
                            acpi_adr_space_type space_id)
{
        union acpi_operand_object *obj_desc;
        union acpi_operand_object *handler_obj;

        /* Must have an existing internal object */

        obj_desc = acpi_ns_get_attached_object(node);
        if (obj_desc) {
                handler_obj = obj_desc->device.handler;

                /* Walk the linked list of handlers for this object */

                while (handler_obj) {
                        if (handler_obj->address_space.space_id == space_id) {
                                if (handler_obj->address_space.handler_flags &
                                    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
                                        return (TRUE);
                                }
                        }

                        handler_obj = handler_obj->address_space.next;
                }
        }

        return (FALSE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_initialize_op_regions
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute _REG methods for all Operation Regions that have
 *              an installed default region handler.
 *
 ******************************************************************************/

acpi_status acpi_ev_initialize_op_regions(void)
{
        acpi_status status;
        u32 i;

        ACPI_FUNCTION_TRACE(ev_initialize_op_regions);

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

        /* Run the _REG methods for op_regions in each default address space */

        for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
                /*
                 * Make sure the installed handler is the DEFAULT handler. If not the
                 * default, the _REG methods will have already been run (when the
                 * handler was installed)
                 */
                if (acpi_ev_has_default_handler(acpi_gbl_root_node,
                                                acpi_gbl_default_address_spaces
                                                [i])) {
                        status =
                            acpi_ev_execute_reg_methods(acpi_gbl_root_node,
                                                        acpi_gbl_default_address_spaces
                                                        [i]);
                }
        }

        acpi_gbl_reg_methods_executed = TRUE;

        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_execute_reg_method
 *
 * PARAMETERS:  region_obj          - Region object
 *              function            - Passed to _REG: On (1) or Off (0)
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Execute _REG method for a region
 *
 ******************************************************************************/

acpi_status
acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
{
        struct acpi_evaluate_info *info;
        union acpi_operand_object *args[3];
        union acpi_operand_object *region_obj2;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ev_execute_reg_method);

        region_obj2 = acpi_ns_get_secondary_object(region_obj);
        if (!region_obj2) {
                return_ACPI_STATUS(AE_NOT_EXIST);
        }

        if (region_obj2->extra.method_REG == NULL) {
                return_ACPI_STATUS(AE_OK);
        }

        /* Allocate and initialize the evaluation information block */

        info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
        if (!info) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        info->prefix_node = region_obj2->extra.method_REG;
        info->pathname = NULL;
        info->parameters = args;
        info->flags = ACPI_IGNORE_RETURN_VALUE;

        /*
         * The _REG method has two arguments:
         *
         * arg0 - Integer:
         *  Operation region space ID Same value as region_obj->Region.space_id
         *
         * arg1 - Integer:
         *  connection status 1 for connecting the handler, 0 for disconnecting
         *  the handler (Passed as a parameter)
         */
        args[0] =
            acpi_ut_create_integer_object((u64) region_obj->region.space_id);
        if (!args[0]) {
                status = AE_NO_MEMORY;
                goto cleanup1;
        }

        args[1] = acpi_ut_create_integer_object((u64) function);
        if (!args[1]) {
                status = AE_NO_MEMORY;
                goto cleanup2;
        }

        args[2] = NULL;         /* Terminate list */

        /* Execute the method, no return value */

        ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
                        (ACPI_TYPE_METHOD, info->prefix_node, NULL));

        status = acpi_ns_evaluate(info);
        acpi_ut_remove_reference(args[1]);

      cleanup2:
        acpi_ut_remove_reference(args[0]);

      cleanup1:
        ACPI_FREE(info);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_address_space_dispatch
 *
 * PARAMETERS:  region_obj          - Internal region object
 *              field_obj           - Corresponding field. Can be NULL.
 *              function            - Read or Write operation
 *              region_offset       - Where in the region to read or write
 *              bit_width           - Field width in bits (8, 16, 32, or 64)
 *              value               - Pointer to in or out value, must be
 *                                    a full 64-bit integer
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Dispatch an address space or operation region access to
 *              a previously installed handler.
 *
 ******************************************************************************/

acpi_status
acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
                               union acpi_operand_object *field_obj,
                               u32 function,
                               u32 region_offset, u32 bit_width, u64 *value)
{
        acpi_status status;
        acpi_adr_space_handler handler;
        acpi_adr_space_setup region_setup;
        union acpi_operand_object *handler_desc;
        union acpi_operand_object *region_obj2;
        void *region_context = NULL;
        struct acpi_connection_info *context;

        ACPI_FUNCTION_TRACE(ev_address_space_dispatch);

        region_obj2 = acpi_ns_get_secondary_object(region_obj);
        if (!region_obj2) {
                return_ACPI_STATUS(AE_NOT_EXIST);
        }

        /* Ensure that there is a handler associated with this region */

        handler_desc = region_obj->region.handler;
        if (!handler_desc) {
                ACPI_ERROR((AE_INFO,
                            "No handler for Region [%4.4s] (%p) [%s]",
                            acpi_ut_get_node_name(region_obj->region.node),
                            region_obj,
                            acpi_ut_get_region_name(region_obj->region.
                                                    space_id)));

                return_ACPI_STATUS(AE_NOT_EXIST);
        }

        context = handler_desc->address_space.context;

        /*
         * It may be the case that the region has never been initialized.
         * Some types of regions require special init code
         */
        if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {

                /* This region has not been initialized yet, do it */

                region_setup = handler_desc->address_space.setup;
                if (!region_setup) {

                        /* No initialization routine, exit with error */

                        ACPI_ERROR((AE_INFO,
                                    "No init routine for region(%p) [%s]",
                                    region_obj,
                                    acpi_ut_get_region_name(region_obj->region.
                                                            space_id)));
                        return_ACPI_STATUS(AE_NOT_EXIST);
                }

                /*
                 * We must exit the interpreter because the region setup will
                 * potentially execute control methods (for example, the _REG method
                 * for this region)
                 */
                acpi_ex_exit_interpreter();

                status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
                                      context, &region_context);

                /* Re-enter the interpreter */

                acpi_ex_enter_interpreter();

                /* Check for failure of the Region Setup */

                if (ACPI_FAILURE(status)) {
                        ACPI_EXCEPTION((AE_INFO, status,
                                        "During region initialization: [%s]",
                                        acpi_ut_get_region_name(region_obj->
                                                                region.
                                                                space_id)));
                        return_ACPI_STATUS(status);
                }

                /* Region initialization may have been completed by region_setup */

                if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
                        region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;

                        if (region_obj2->extra.region_context) {

                                /* The handler for this region was already installed */

                                ACPI_FREE(region_context);
                        } else {
                                /*
                                 * Save the returned context for use in all accesses to
                                 * this particular region
                                 */
                                region_obj2->extra.region_context =
                                    region_context;
                        }
                }
        }

        /* We have everything we need, we can invoke the address space handler */

        handler = handler_desc->address_space.handler;

        ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                          "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
                          &region_obj->region.handler->address_space, handler,
                          ACPI_FORMAT_NATIVE_UINT(region_obj->region.address +
                                                  region_offset),
                          acpi_ut_get_region_name(region_obj->region.
                                                  space_id)));

        /*
         * Special handling for generic_serial_bus and general_purpose_io:
         * There are three extra parameters that must be passed to the
         * handler via the context:
         *   1) Connection buffer, a resource template from Connection() op.
         *   2) Length of the above buffer.
         *   3) Actual access length from the access_as() op.
         */
        if (((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS) ||
             (region_obj->region.space_id == ACPI_ADR_SPACE_GPIO)) &&
            context && field_obj) {

                /* Get the Connection (resource_template) buffer */

                context->connection = field_obj->field.resource_buffer;
                context->length = field_obj->field.resource_length;
                context->access_length = field_obj->field.access_length;
        }

        if (!(handler_desc->address_space.handler_flags &
              ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
                /*
                 * For handlers other than the default (supplied) handlers, we must
                 * exit the interpreter because the handler *might* block -- we don't
                 * know what it will do, so we can't hold the lock on the intepreter.
                 */
                acpi_ex_exit_interpreter();
        }

        /* Call the handler */

        status = handler(function,
                         (region_obj->region.address + region_offset),
                         bit_width, value, context,
                         region_obj2->extra.region_context);

        if (ACPI_FAILURE(status)) {
                ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
                                acpi_ut_get_region_name(region_obj->region.
                                                        space_id)));
        }

        if (!(handler_desc->address_space.handler_flags &
              ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
                /*
                 * We just returned from a non-default handler, we must re-enter the
                 * interpreter
                 */
                acpi_ex_enter_interpreter();
        }

        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_detach_region
 *
 * PARAMETERS:  region_obj          - Region Object
 *              acpi_ns_is_locked   - Namespace Region Already Locked?
 *
 * RETURN:      None
 *
 * DESCRIPTION: Break the association between the handler and the region
 *              this is a two way association.
 *
 ******************************************************************************/

void
acpi_ev_detach_region(union acpi_operand_object *region_obj,
                      u8 acpi_ns_is_locked)
{
        union acpi_operand_object *handler_obj;
        union acpi_operand_object *obj_desc;
        union acpi_operand_object **last_obj_ptr;
        acpi_adr_space_setup region_setup;
        void **region_context;
        union acpi_operand_object *region_obj2;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ev_detach_region);

        region_obj2 = acpi_ns_get_secondary_object(region_obj);
        if (!region_obj2) {
                return_VOID;
        }
        region_context = &region_obj2->extra.region_context;

        /* Get the address handler from the region object */

        handler_obj = region_obj->region.handler;
        if (!handler_obj) {

                /* This region has no handler, all done */

                return_VOID;
        }

        /* Find this region in the handler's list */

        obj_desc = handler_obj->address_space.region_list;
        last_obj_ptr = &handler_obj->address_space.region_list;

        while (obj_desc) {

                /* Is this the correct Region? */

                if (obj_desc == region_obj) {
                        ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                                          "Removing Region %p from address handler %p\n",
                                          region_obj, handler_obj));

                        /* This is it, remove it from the handler's list */

                        *last_obj_ptr = obj_desc->region.next;
                        obj_desc->region.next = NULL;   /* Must clear field */

                        if (acpi_ns_is_locked) {
                                status =
                                    acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
                                if (ACPI_FAILURE(status)) {
                                        return_VOID;
                                }
                        }

                        /* Now stop region accesses by executing the _REG method */

                        status =
                            acpi_ev_execute_reg_method(region_obj,
                                                       ACPI_REG_DISCONNECT);
                        if (ACPI_FAILURE(status)) {
                                ACPI_EXCEPTION((AE_INFO, status,
                                                "from region _REG, [%s]",
                                                acpi_ut_get_region_name
                                                (region_obj->region.space_id)));
                        }

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

                        /*
                         * If the region has been activated, call the setup handler with
                         * the deactivate notification
                         */
                        if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
                                region_setup = handler_obj->address_space.setup;
                                status =
                                    region_setup(region_obj,
                                                 ACPI_REGION_DEACTIVATE,
                                                 handler_obj->address_space.
                                                 context, region_context);

                                /* Init routine may fail, Just ignore errors */

                                if (ACPI_FAILURE(status)) {
                                        ACPI_EXCEPTION((AE_INFO, status,
                                                        "from region handler - deactivate, [%s]",
                                                        acpi_ut_get_region_name
                                                        (region_obj->region.
                                                         space_id)));
                                }

                                region_obj->region.flags &=
                                    ~(AOPOBJ_SETUP_COMPLETE);
                        }

                        /*
                         * Remove handler reference in the region
                         *
                         * NOTE: this doesn't mean that the region goes away, the region
                         * is just inaccessible as indicated to the _REG method
                         *
                         * If the region is on the handler's list, this must be the
                         * region's handler
                         */
                        region_obj->region.handler = NULL;
                        acpi_ut_remove_reference(handler_obj);

                        return_VOID;
                }

                /* Walk the linked list of handlers */

                last_obj_ptr = &obj_desc->region.next;
                obj_desc = obj_desc->region.next;
        }

        /* If we get here, the region was not in the handler's region list */

        ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                          "Cannot remove region %p from address handler %p\n",
                          region_obj, handler_obj));

        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_attach_region
 *
 * PARAMETERS:  handler_obj         - Handler Object
 *              region_obj          - Region Object
 *              acpi_ns_is_locked   - Namespace Region Already Locked?
 *
 * RETURN:      None
 *
 * DESCRIPTION: Create the association between the handler and the region
 *              this is a two way association.
 *
 ******************************************************************************/

acpi_status
acpi_ev_attach_region(union acpi_operand_object *handler_obj,
                      union acpi_operand_object *region_obj,
                      u8 acpi_ns_is_locked)
{

        ACPI_FUNCTION_TRACE(ev_attach_region);

        ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                          "Adding Region [%4.4s] %p to address handler %p [%s]\n",
                          acpi_ut_get_node_name(region_obj->region.node),
                          region_obj, handler_obj,
                          acpi_ut_get_region_name(region_obj->region.
                                                  space_id)));

        /* Link this region to the front of the handler's list */

        region_obj->region.next = handler_obj->address_space.region_list;
        handler_obj->address_space.region_list = region_obj;

        /* Install the region's handler */

        if (region_obj->region.handler) {
                return_ACPI_STATUS(AE_ALREADY_EXISTS);
        }

        region_obj->region.handler = handler_obj;
        acpi_ut_add_reference(handler_obj);

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_install_handler
 *
 * PARAMETERS:  walk_namespace callback
 *
 * DESCRIPTION: This routine installs an address handler into objects that are
 *              of type Region or Device.
 *
 *              If the Object is a Device, and the device has a handler of
 *              the same type then the search is terminated in that branch.
 *
 *              This is because the existing handler is closer in proximity
 *              to any more regions than the one we are trying to install.
 *
 ******************************************************************************/

static acpi_status
acpi_ev_install_handler(acpi_handle obj_handle,
                        u32 level, void *context, void **return_value)
{
        union acpi_operand_object *handler_obj;
        union acpi_operand_object *next_handler_obj;
        union acpi_operand_object *obj_desc;
        struct acpi_namespace_node *node;
        acpi_status status;

        ACPI_FUNCTION_NAME(ev_install_handler);

        handler_obj = (union acpi_operand_object *)context;

        /* Parameter validation */

        if (!handler_obj) {
                return (AE_OK);
        }

        /* Convert and validate the device handle */

        node = acpi_ns_validate_handle(obj_handle);
        if (!node) {
                return (AE_BAD_PARAMETER);
        }

        /*
         * We only care about regions and objects that are allowed to have
         * address space handlers
         */
        if ((node->type != ACPI_TYPE_DEVICE) &&
            (node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
                return (AE_OK);
        }

        /* Check for an existing internal object */

        obj_desc = acpi_ns_get_attached_object(node);
        if (!obj_desc) {

                /* No object, just exit */

                return (AE_OK);
        }

        /* Devices are handled different than regions */

        if (obj_desc->common.type == ACPI_TYPE_DEVICE) {

                /* Check if this Device already has a handler for this address space */

                next_handler_obj = obj_desc->device.handler;
                while (next_handler_obj) {

                        /* Found a handler, is it for the same address space? */

                        if (next_handler_obj->address_space.space_id ==
                            handler_obj->address_space.space_id) {
                                ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                                                  "Found handler for region [%s] in device %p(%p) "
                                                  "handler %p\n",
                                                  acpi_ut_get_region_name
                                                  (handler_obj->address_space.
                                                   space_id), obj_desc,
                                                  next_handler_obj,
                                                  handler_obj));

                                /*
                                 * Since the object we found it on was a device, then it
                                 * means that someone has already installed a handler for
                                 * the branch of the namespace from this device on. Just
                                 * bail out telling the walk routine to not traverse this
                                 * branch. This preserves the scoping rule for handlers.
                                 */
                                return (AE_CTRL_DEPTH);
                        }

                        /* Walk the linked list of handlers attached to this device */

                        next_handler_obj = next_handler_obj->address_space.next;
                }

                /*
                 * As long as the device didn't have a handler for this space we
                 * don't care about it. We just ignore it and proceed.
                 */
                return (AE_OK);
        }

        /* Object is a Region */

        if (obj_desc->region.space_id != handler_obj->address_space.space_id) {

                /* This region is for a different address space, just ignore it */

                return (AE_OK);
        }

        /*
         * Now we have a region and it is for the handler's address space type.
         *
         * First disconnect region for any previous handler (if any)
         */
        acpi_ev_detach_region(obj_desc, FALSE);

        /* Connect the region to the new handler */

        status = acpi_ev_attach_region(handler_obj, obj_desc, FALSE);
        return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_install_space_handler
 *
 * PARAMETERS:  node            - Namespace node for the device
 *              space_id        - The address space ID
 *              handler         - Address of the handler
 *              setup           - Address of the setup function
 *              context         - Value passed to the handler on each access
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for all op_regions of a given space_id.
 *              Assumes namespace is locked
 *
 ******************************************************************************/

acpi_status
acpi_ev_install_space_handler(struct acpi_namespace_node * node,
                              acpi_adr_space_type space_id,
                              acpi_adr_space_handler handler,
                              acpi_adr_space_setup setup, void *context)
{
        union acpi_operand_object *obj_desc;
        union acpi_operand_object *handler_obj;
        acpi_status status;
        acpi_object_type type;
        u8 flags = 0;

        ACPI_FUNCTION_TRACE(ev_install_space_handler);

        /*
         * This registration is valid for only the types below and the root. This
         * is where the default handlers get placed.
         */
        if ((node->type != ACPI_TYPE_DEVICE) &&
            (node->type != ACPI_TYPE_PROCESSOR) &&
            (node->type != ACPI_TYPE_THERMAL) && (node != acpi_gbl_root_node)) {
                status = AE_BAD_PARAMETER;
                goto unlock_and_exit;
        }

        if (handler == ACPI_DEFAULT_HANDLER) {
                flags = ACPI_ADDR_HANDLER_DEFAULT_INSTALLED;

                switch (space_id) {
                case ACPI_ADR_SPACE_SYSTEM_MEMORY:
                        handler = acpi_ex_system_memory_space_handler;
                        setup = acpi_ev_system_memory_region_setup;
                        break;

                case ACPI_ADR_SPACE_SYSTEM_IO:
                        handler = acpi_ex_system_io_space_handler;
                        setup = acpi_ev_io_space_region_setup;
                        break;

                case ACPI_ADR_SPACE_PCI_CONFIG:
                        handler = acpi_ex_pci_config_space_handler;
                        setup = acpi_ev_pci_config_region_setup;
                        break;

                case ACPI_ADR_SPACE_CMOS:
                        handler = acpi_ex_cmos_space_handler;
                        setup = acpi_ev_cmos_region_setup;
                        break;

                case ACPI_ADR_SPACE_PCI_BAR_TARGET:
                        handler = acpi_ex_pci_bar_space_handler;
                        setup = acpi_ev_pci_bar_region_setup;
                        break;

                case ACPI_ADR_SPACE_DATA_TABLE:
                        handler = acpi_ex_data_table_space_handler;
                        setup = NULL;
                        break;

                default:
                        status = AE_BAD_PARAMETER;
                        goto unlock_and_exit;
                }
        }

        /* If the caller hasn't specified a setup routine, use the default */

        if (!setup) {
                setup = acpi_ev_default_region_setup;
        }

        /* Check for an existing internal object */

        obj_desc = acpi_ns_get_attached_object(node);
        if (obj_desc) {
                /*
                 * The attached device object already exists. Make sure the handler
                 * is not already installed.
                 */
                handler_obj = obj_desc->device.handler;

                /* Walk the handler list for this device */

                while (handler_obj) {

                        /* Same space_id indicates a handler already installed */

                        if (handler_obj->address_space.space_id == space_id) {
                                if (handler_obj->address_space.handler ==
                                    handler) {
                                        /*
                                         * It is (relatively) OK to attempt to install the SAME
                                         * handler twice. This can easily happen with the
                                         * PCI_Config space.
                                         */
                                        status = AE_SAME_HANDLER;
                                        goto unlock_and_exit;
                                } else {
                                        /* A handler is already installed */

                                        status = AE_ALREADY_EXISTS;
                                }
                                goto unlock_and_exit;
                        }

                        /* Walk the linked list of handlers */

                        handler_obj = handler_obj->address_space.next;
                }
        } else {
                ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                                  "Creating object on Device %p while installing handler\n",
                                  node));

                /* obj_desc does not exist, create one */

                if (node->type == ACPI_TYPE_ANY) {
                        type = ACPI_TYPE_DEVICE;
                } else {
                        type = node->type;
                }

                obj_desc = acpi_ut_create_internal_object(type);
                if (!obj_desc) {
                        status = AE_NO_MEMORY;
                        goto unlock_and_exit;
                }

                /* Init new descriptor */

                obj_desc->common.type = (u8) type;

                /* Attach the new object to the Node */

                status = acpi_ns_attach_object(node, obj_desc, type);

                /* Remove local reference to the object */

                acpi_ut_remove_reference(obj_desc);

                if (ACPI_FAILURE(status)) {
                        goto unlock_and_exit;
                }
        }

        ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
                          "Installing address handler for region %s(%X) on Device %4.4s %p(%p)\n",
                          acpi_ut_get_region_name(space_id), space_id,
                          acpi_ut_get_node_name(node), node, obj_desc));

        /*
         * Install the handler
         *
         * At this point there is no existing handler. Just allocate the object
         * for the handler and link it into the list.
         */
        handler_obj =
            acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_ADDRESS_HANDLER);
        if (!handler_obj) {
                status = AE_NO_MEMORY;
                goto unlock_and_exit;
        }

        /* Init handler obj */

        handler_obj->address_space.space_id = (u8) space_id;
        handler_obj->address_space.handler_flags = flags;
        handler_obj->address_space.region_list = NULL;
        handler_obj->address_space.node = node;
        handler_obj->address_space.handler = handler;
        handler_obj->address_space.context = context;
        handler_obj->address_space.setup = setup;

        /* Install at head of Device.address_space list */

        handler_obj->address_space.next = obj_desc->device.handler;

        /*
         * The Device object is the first reference on the handler_obj.
         * Each region that uses the handler adds a reference.
         */
        obj_desc->device.handler = handler_obj;

        /*
         * Walk the namespace finding all of the regions this
         * handler will manage.
         *
         * Start at the device and search the branch toward
         * the leaf nodes until either the leaf is encountered or
         * a device is detected that has an address handler of the
         * same type.
         *
         * In either case, back up and search down the remainder
         * of the branch
         */
        status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
                                        ACPI_NS_WALK_UNLOCK,
                                        acpi_ev_install_handler, NULL,
                                        handler_obj, NULL);

      unlock_and_exit:
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_execute_reg_methods
 *
 * PARAMETERS:  node            - Namespace node for the device
 *              space_id        - The address space ID
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Run all _REG methods for the input Space ID;
 *              Note: assumes namespace is locked, or system init time.
 *
 ******************************************************************************/

acpi_status
acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
                            acpi_adr_space_type space_id)
{
        acpi_status status;

        ACPI_FUNCTION_TRACE(ev_execute_reg_methods);

        /*
         * Run all _REG methods for all Operation Regions for this space ID. This
         * is a separate walk in order to handle any interdependencies between
         * regions and _REG methods. (i.e. handlers must be installed for all
         * regions of this Space ID before we can run any _REG methods)
         */
        status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
                                        ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run,
                                        NULL, &space_id, NULL);

        /* Special case for EC: handle "orphan" _REG methods with no region */

        if (space_id == ACPI_ADR_SPACE_EC) {
                acpi_ev_orphan_ec_reg_method();
        }

        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_reg_run
 *
 * PARAMETERS:  walk_namespace callback
 *
 * DESCRIPTION: Run _REG method for region objects of the requested spaceID
 *
 ******************************************************************************/

static acpi_status
acpi_ev_reg_run(acpi_handle obj_handle,
                u32 level, void *context, void **return_value)
{
        union acpi_operand_object *obj_desc;
        struct acpi_namespace_node *node;
        acpi_adr_space_type space_id;
        acpi_status status;

        space_id = *ACPI_CAST_PTR(acpi_adr_space_type, context);

        /* Convert and validate the device handle */

        node = acpi_ns_validate_handle(obj_handle);
        if (!node) {
                return (AE_BAD_PARAMETER);
        }

        /*
         * We only care about regions.and objects that are allowed to have address
         * space handlers
         */
        if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
                return (AE_OK);
        }

        /* Check for an existing internal object */

        obj_desc = acpi_ns_get_attached_object(node);
        if (!obj_desc) {

                /* No object, just exit */

                return (AE_OK);
        }

        /* Object is a Region */

        if (obj_desc->region.space_id != space_id) {

                /* This region is for a different address space, just ignore it */

                return (AE_OK);
        }

        status = acpi_ev_execute_reg_method(obj_desc, ACPI_REG_CONNECT);
        return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_orphan_ec_reg_method
 *
 * PARAMETERS:  None
 *
 * RETURN:      None
 *
 * DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
 *              device. This is a _REG method that has no corresponding region
 *              within the EC device scope. The orphan _REG method appears to
 *              have been enabled by the description of the ECDT in the ACPI
 *              specification: "The availability of the region space can be
 *              detected by providing a _REG method object underneath the
 *              Embedded Controller device."
 *
 *              To quickly access the EC device, we use the EC_ID that appears
 *              within the ECDT. Otherwise, we would need to perform a time-
 *              consuming namespace walk, executing _HID methods to find the
 *              EC device.
 *
 ******************************************************************************/

static void acpi_ev_orphan_ec_reg_method(void)
{
        struct acpi_table_ecdt *table;
        acpi_status status;
        struct acpi_object_list args;
        union acpi_object objects[2];
        struct acpi_namespace_node *ec_device_node;
        struct acpi_namespace_node *reg_method;
        struct acpi_namespace_node *next_node;

        ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);

        /* Get the ECDT (if present in system) */

        status = acpi_get_table(ACPI_SIG_ECDT, 0,
                                ACPI_CAST_INDIRECT_PTR(struct acpi_table_header,
                                                       &table));
        if (ACPI_FAILURE(status)) {
                return_VOID;
        }

        /* We need a valid EC_ID string */

        if (!(*table->id)) {
                return_VOID;
        }

        /* Namespace is currently locked, must release */

        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

        /* Get a handle to the EC device referenced in the ECDT */

        status = acpi_get_handle(NULL,
                                 ACPI_CAST_PTR(char, table->id),
                                 ACPI_CAST_PTR(acpi_handle, &ec_device_node));
        if (ACPI_FAILURE(status)) {
                goto exit;
        }

        /* Get a handle to a _REG method immediately under the EC device */

        status = acpi_get_handle(ec_device_node,
                                 METHOD_NAME__REG, ACPI_CAST_PTR(acpi_handle,
                                                                 &reg_method));
        if (ACPI_FAILURE(status)) {
                goto exit;
        }

        /*
         * Execute the _REG method only if there is no Operation Region in
         * this scope with the Embedded Controller space ID. Otherwise, it
         * will already have been executed. Note, this allows for Regions
         * with other space IDs to be present; but the code below will then
         * execute the _REG method with the EC space ID argument.
         */
        next_node = acpi_ns_get_next_node(ec_device_node, NULL);
        while (next_node) {
                if ((next_node->type == ACPI_TYPE_REGION) &&
                    (next_node->object) &&
                    (next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
                        goto exit;      /* Do not execute _REG */
                }
                next_node = acpi_ns_get_next_node(ec_device_node, next_node);
        }

        /* Evaluate the _REG(EC,Connect) method */

        args.count = 2;
        args.pointer = objects;
        objects[0].type = ACPI_TYPE_INTEGER;
        objects[0].integer.value = ACPI_ADR_SPACE_EC;
        objects[1].type = ACPI_TYPE_INTEGER;
        objects[1].integer.value = ACPI_REG_CONNECT;

        status = acpi_evaluate_object(reg_method, NULL, &args, NULL);

      exit:
        /* We ignore all errors from above, don't care */

        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
        return_VOID;
}