// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: evhandler - Support for Address Space handlers
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

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

#define _COMPONENT          ACPI_EVENTS
ACPI_MODULE_NAME("evhandler")

/* Local prototypes */
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 */

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.
 *
 ******************************************************************************/

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->common_notify.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_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 =
                    acpi_ev_find_region_handler(handler_obj->address_space.
                                                space_id,
                                                obj_desc->common_notify.
                                                handler);
                if (next_handler_obj) {

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

                        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);
                }

                /*
                 * 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_find_region_handler
 *
 * PARAMETERS:  space_id        - The address space ID
 *              handler_obj     - Head of the handler object list
 *
 * RETURN:      Matching handler object. NULL if space ID not matched
 *
 * DESCRIPTION: Search a handler object list for a match on the address
 *              space ID.
 *
 ******************************************************************************/

union acpi_operand_object *acpi_ev_find_region_handler(acpi_adr_space_type
                                                       space_id,
                                                       union acpi_operand_object
                                                       *handler_obj)
{

        /* Walk the handler list for this device */

        while (handler_obj) {

                /* Same space_id indicates a handler is installed */

                if (handler_obj->address_space.space_id == space_id) {
                        return (handler_obj);
                }

                /* Next handler object */

                handler_obj = handler_obj->address_space.next;
        }

        return (NULL);
}

/*******************************************************************************
 *
 * 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 = AE_OK;
        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.
         * The root node is where the default handlers get installed.
         */
        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;
#ifdef ACPI_PCI_CONFIGURED
                case ACPI_ADR_SPACE_PCI_CONFIG:

                        handler = acpi_ex_pci_config_space_handler;
                        setup = acpi_ev_pci_config_region_setup;
                        break;
#endif
                case ACPI_ADR_SPACE_CMOS:

                        handler = acpi_ex_cmos_space_handler;
                        setup = acpi_ev_cmos_region_setup;
                        break;
#ifdef ACPI_PCI_CONFIGURED
                case ACPI_ADR_SPACE_PCI_BAR_TARGET:

                        handler = acpi_ex_pci_bar_space_handler;
                        setup = acpi_ev_pci_bar_region_setup;
                        break;
#endif
                case ACPI_ADR_SPACE_DATA_TABLE:

                        handler = acpi_ex_data_table_space_handler;
                        setup = acpi_ev_data_table_region_setup;
                        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. Now make sure
                 * the handler is not already installed.
                 */
                handler_obj = acpi_ev_find_region_handler(space_id,
                                                          obj_desc->
                                                          common_notify.
                                                          handler);

                if (handler_obj) {
                        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;
                }
        } 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 */

        status =
            acpi_os_create_mutex(&handler_obj->address_space.context_mutex);
        if (ACPI_FAILURE(status)) {
                acpi_ut_remove_reference(handler_obj);
                goto unlock_and_exit;
        }

        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->common_notify.handler;

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