lkdtm: Add Control Flow Integrity test

[linux/fpc-iii.git] / drivers / acpi / property.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * ACPI device specific properties support.
 *
 * Copyright (C) 2014, Intel Corporation
 * All rights reserved.
 *
 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
 *          Darren Hart <dvhart@linux.intel.com>
 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 */

#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>

#include "internal.h"

static int acpi_data_get_property_array(const struct acpi_device_data *data,
                                        const char *name,
                                        acpi_object_type type,
                                        const union acpi_object **obj);

/*
 * The GUIDs here are made equivalent to each other in order to avoid extra
 * complexity in the properties handling code, with the caveat that the
 * kernel will accept certain combinations of GUID and properties that are
 * not defined without a warning. For instance if any of the properties
 * from different GUID appear in a property list of another, it will be
 * accepted by the kernel. Firmware validation tools should catch these.
 */
static const guid_t prp_guids[] = {
        /* ACPI _DSD device properties GUID: daffd814-6eba-4d8c-8a91-bc9bbf4aa301 */
        GUID_INIT(0xdaffd814, 0x6eba, 0x4d8c,
                  0x8a, 0x91, 0xbc, 0x9b, 0xbf, 0x4a, 0xa3, 0x01),
        /* Hotplug in D3 GUID: 6211e2c0-58a3-4af3-90e1-927a4e0c55a4 */
        GUID_INIT(0x6211e2c0, 0x58a3, 0x4af3,
                  0x90, 0xe1, 0x92, 0x7a, 0x4e, 0x0c, 0x55, 0xa4),
        /* External facing port GUID: efcc06cc-73ac-4bc3-bff0-76143807c389 */
        GUID_INIT(0xefcc06cc, 0x73ac, 0x4bc3,
                  0xbf, 0xf0, 0x76, 0x14, 0x38, 0x07, 0xc3, 0x89),
};

/* ACPI _DSD data subnodes GUID: dbb8e3e6-5886-4ba6-8795-1319f52a966b */
static const guid_t ads_guid =
        GUID_INIT(0xdbb8e3e6, 0x5886, 0x4ba6,
                  0x87, 0x95, 0x13, 0x19, 0xf5, 0x2a, 0x96, 0x6b);

static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
                                           const union acpi_object *desc,
                                           struct acpi_device_data *data,
                                           struct fwnode_handle *parent);
static bool acpi_extract_properties(const union acpi_object *desc,
                                    struct acpi_device_data *data);

static bool acpi_nondev_subnode_extract(const union acpi_object *desc,
                                        acpi_handle handle,
                                        const union acpi_object *link,
                                        struct list_head *list,
                                        struct fwnode_handle *parent)
{
        struct acpi_data_node *dn;
        bool result;

        dn = kzalloc(sizeof(*dn), GFP_KERNEL);
        if (!dn)
                return false;

        dn->name = link->package.elements[0].string.pointer;
        dn->fwnode.ops = &acpi_data_fwnode_ops;
        dn->parent = parent;
        INIT_LIST_HEAD(&dn->data.properties);
        INIT_LIST_HEAD(&dn->data.subnodes);

        result = acpi_extract_properties(desc, &dn->data);

        if (handle) {
                acpi_handle scope;
                acpi_status status;

                /*
                 * The scope for the subnode object lookup is the one of the
                 * namespace node (device) containing the object that has
                 * returned the package.  That is, it's the scope of that
                 * object's parent.
                 */
                status = acpi_get_parent(handle, &scope);
                if (ACPI_SUCCESS(status)
                    && acpi_enumerate_nondev_subnodes(scope, desc, &dn->data,
                                                      &dn->fwnode))
                        result = true;
        } else if (acpi_enumerate_nondev_subnodes(NULL, desc, &dn->data,
                                                  &dn->fwnode)) {
                result = true;
        }

        if (result) {
                dn->handle = handle;
                dn->data.pointer = desc;
                list_add_tail(&dn->sibling, list);
                return true;
        }

        kfree(dn);
        acpi_handle_debug(handle, "Invalid properties/subnodes data, skipping\n");
        return false;
}

static bool acpi_nondev_subnode_data_ok(acpi_handle handle,
                                        const union acpi_object *link,
                                        struct list_head *list,
                                        struct fwnode_handle *parent)
{
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
        acpi_status status;

        status = acpi_evaluate_object_typed(handle, NULL, NULL, &buf,
                                            ACPI_TYPE_PACKAGE);
        if (ACPI_FAILURE(status))
                return false;

        if (acpi_nondev_subnode_extract(buf.pointer, handle, link, list,
                                        parent))
                return true;

        ACPI_FREE(buf.pointer);
        return false;
}

static bool acpi_nondev_subnode_ok(acpi_handle scope,
                                   const union acpi_object *link,
                                   struct list_head *list,
                                   struct fwnode_handle *parent)
{
        acpi_handle handle;
        acpi_status status;

        if (!scope)
                return false;

        status = acpi_get_handle(scope, link->package.elements[1].string.pointer,
                                 &handle);
        if (ACPI_FAILURE(status))
                return false;

        return acpi_nondev_subnode_data_ok(handle, link, list, parent);
}

static int acpi_add_nondev_subnodes(acpi_handle scope,
                                    const union acpi_object *links,
                                    struct list_head *list,
                                    struct fwnode_handle *parent)
{
        bool ret = false;
        int i;

        for (i = 0; i < links->package.count; i++) {
                const union acpi_object *link, *desc;
                acpi_handle handle;
                bool result;

                link = &links->package.elements[i];
                /* Only two elements allowed. */
                if (link->package.count != 2)
                        continue;

                /* The first one must be a string. */
                if (link->package.elements[0].type != ACPI_TYPE_STRING)
                        continue;

                /* The second one may be a string, a reference or a package. */
                switch (link->package.elements[1].type) {
                case ACPI_TYPE_STRING:
                        result = acpi_nondev_subnode_ok(scope, link, list,
                                                         parent);
                        break;
                case ACPI_TYPE_LOCAL_REFERENCE:
                        handle = link->package.elements[1].reference.handle;
                        result = acpi_nondev_subnode_data_ok(handle, link, list,
                                                             parent);
                        break;
                case ACPI_TYPE_PACKAGE:
                        desc = &link->package.elements[1];
                        result = acpi_nondev_subnode_extract(desc, NULL, link,
                                                             list, parent);
                        break;
                default:
                        result = false;
                        break;
                }
                ret = ret || result;
        }

        return ret;
}

static bool acpi_enumerate_nondev_subnodes(acpi_handle scope,
                                           const union acpi_object *desc,
                                           struct acpi_device_data *data,
                                           struct fwnode_handle *parent)
{
        int i;

        /* Look for the ACPI data subnodes GUID. */
        for (i = 0; i < desc->package.count; i += 2) {
                const union acpi_object *guid, *links;

                guid = &desc->package.elements[i];
                links = &desc->package.elements[i + 1];

                /*
                 * The first element must be a GUID and the second one must be
                 * a package.
                 */
                if (guid->type != ACPI_TYPE_BUFFER ||
                    guid->buffer.length != 16 ||
                    links->type != ACPI_TYPE_PACKAGE)
                        break;

                if (!guid_equal((guid_t *)guid->buffer.pointer, &ads_guid))
                        continue;

                return acpi_add_nondev_subnodes(scope, links, &data->subnodes,
                                                parent);
        }

        return false;
}

static bool acpi_property_value_ok(const union acpi_object *value)
{
        int j;

        /*
         * The value must be an integer, a string, a reference, or a package
         * whose every element must be an integer, a string, or a reference.
         */
        switch (value->type) {
        case ACPI_TYPE_INTEGER:
        case ACPI_TYPE_STRING:
        case ACPI_TYPE_LOCAL_REFERENCE:
                return true;

        case ACPI_TYPE_PACKAGE:
                for (j = 0; j < value->package.count; j++)
                        switch (value->package.elements[j].type) {
                        case ACPI_TYPE_INTEGER:
                        case ACPI_TYPE_STRING:
                        case ACPI_TYPE_LOCAL_REFERENCE:
                                continue;

                        default:
                                return false;
                        }

                return true;
        }
        return false;
}

static bool acpi_properties_format_valid(const union acpi_object *properties)
{
        int i;

        for (i = 0; i < properties->package.count; i++) {
                const union acpi_object *property;

                property = &properties->package.elements[i];
                /*
                 * Only two elements allowed, the first one must be a string and
                 * the second one has to satisfy certain conditions.
                 */
                if (property->package.count != 2
                    || property->package.elements[0].type != ACPI_TYPE_STRING
                    || !acpi_property_value_ok(&property->package.elements[1]))
                        return false;
        }
        return true;
}

static void acpi_init_of_compatible(struct acpi_device *adev)
{
        const union acpi_object *of_compatible;
        int ret;

        ret = acpi_data_get_property_array(&adev->data, "compatible",
                                           ACPI_TYPE_STRING, &of_compatible);
        if (ret) {
                ret = acpi_dev_get_property(adev, "compatible",
                                            ACPI_TYPE_STRING, &of_compatible);
                if (ret) {
                        if (adev->parent
                            && adev->parent->flags.of_compatible_ok)
                                goto out;

                        return;
                }
        }
        adev->data.of_compatible = of_compatible;

 out:
        adev->flags.of_compatible_ok = 1;
}

static bool acpi_is_property_guid(const guid_t *guid)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(prp_guids); i++) {
                if (guid_equal(guid, &prp_guids[i]))
                        return true;
        }

        return false;
}

struct acpi_device_properties *
acpi_data_add_props(struct acpi_device_data *data, const guid_t *guid,
                    const union acpi_object *properties)
{
        struct acpi_device_properties *props;

        props = kzalloc(sizeof(*props), GFP_KERNEL);
        if (props) {
                INIT_LIST_HEAD(&props->list);
                props->guid = guid;
                props->properties = properties;
                list_add_tail(&props->list, &data->properties);
        }

        return props;
}

static bool acpi_extract_properties(const union acpi_object *desc,
                                    struct acpi_device_data *data)
{
        int i;

        if (desc->package.count % 2)
                return false;

        /* Look for the device properties GUID. */
        for (i = 0; i < desc->package.count; i += 2) {
                const union acpi_object *guid, *properties;

                guid = &desc->package.elements[i];
                properties = &desc->package.elements[i + 1];

                /*
                 * The first element must be a GUID and the second one must be
                 * a package.
                 */
                if (guid->type != ACPI_TYPE_BUFFER ||
                    guid->buffer.length != 16 ||
                    properties->type != ACPI_TYPE_PACKAGE)
                        break;

                if (!acpi_is_property_guid((guid_t *)guid->buffer.pointer))
                        continue;

                /*
                 * We found the matching GUID. Now validate the format of the
                 * package immediately following it.
                 */
                if (!acpi_properties_format_valid(properties))
                        continue;

                acpi_data_add_props(data, (const guid_t *)guid->buffer.pointer,
                                    properties);
        }

        return !list_empty(&data->properties);
}

void acpi_init_properties(struct acpi_device *adev)
{
        struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
        struct acpi_hardware_id *hwid;
        acpi_status status;
        bool acpi_of = false;

        INIT_LIST_HEAD(&adev->data.properties);
        INIT_LIST_HEAD(&adev->data.subnodes);

        if (!adev->handle)
                return;

        /*
         * Check if ACPI_DT_NAMESPACE_HID is present and inthat case we fill in
         * Device Tree compatible properties for this device.
         */
        list_for_each_entry(hwid, &adev->pnp.ids, list) {
                if (!strcmp(hwid->id, ACPI_DT_NAMESPACE_HID)) {
                        acpi_of = true;
                        break;
                }
        }

        status = acpi_evaluate_object_typed(adev->handle, "_DSD", NULL, &buf,
                                            ACPI_TYPE_PACKAGE);
        if (ACPI_FAILURE(status))
                goto out;

        if (acpi_extract_properties(buf.pointer, &adev->data)) {
                adev->data.pointer = buf.pointer;
                if (acpi_of)
                        acpi_init_of_compatible(adev);
        }
        if (acpi_enumerate_nondev_subnodes(adev->handle, buf.pointer,
                                        &adev->data, acpi_fwnode_handle(adev)))
                adev->data.pointer = buf.pointer;

        if (!adev->data.pointer) {
                acpi_handle_debug(adev->handle, "Invalid _DSD data, skipping\n");
                ACPI_FREE(buf.pointer);
        }

 out:
        if (acpi_of && !adev->flags.of_compatible_ok)
                acpi_handle_info(adev->handle,
                         ACPI_DT_NAMESPACE_HID " requires 'compatible' property\n");

        if (!adev->data.pointer)
                acpi_extract_apple_properties(adev);
}

static void acpi_destroy_nondev_subnodes(struct list_head *list)
{
        struct acpi_data_node *dn, *next;

        if (list_empty(list))
                return;

        list_for_each_entry_safe_reverse(dn, next, list, sibling) {
                acpi_destroy_nondev_subnodes(&dn->data.subnodes);
                wait_for_completion(&dn->kobj_done);
                list_del(&dn->sibling);
                ACPI_FREE((void *)dn->data.pointer);
                kfree(dn);
        }
}

void acpi_free_properties(struct acpi_device *adev)
{
        struct acpi_device_properties *props, *tmp;

        acpi_destroy_nondev_subnodes(&adev->data.subnodes);
        ACPI_FREE((void *)adev->data.pointer);
        adev->data.of_compatible = NULL;
        adev->data.pointer = NULL;
        list_for_each_entry_safe(props, tmp, &adev->data.properties, list) {
                list_del(&props->list);
                kfree(props);
        }
}

/**
 * acpi_data_get_property - return an ACPI property with given name
 * @data: ACPI device deta object to get the property from
 * @name: Name of the property
 * @type: Expected property type
 * @obj: Location to store the property value (if not %NULL)
 *
 * Look up a property with @name and store a pointer to the resulting ACPI
 * object at the location pointed to by @obj if found.
 *
 * Callers must not attempt to free the returned objects.  These objects will be
 * freed by the ACPI core automatically during the removal of @data.
 *
 * Return: %0 if property with @name has been found (success),
 *         %-EINVAL if the arguments are invalid,
 *         %-EINVAL if the property doesn't exist,
 *         %-EPROTO if the property value type doesn't match @type.
 */
static int acpi_data_get_property(const struct acpi_device_data *data,
                                  const char *name, acpi_object_type type,
                                  const union acpi_object **obj)
{
        const struct acpi_device_properties *props;

        if (!data || !name)
                return -EINVAL;

        if (!data->pointer || list_empty(&data->properties))
                return -EINVAL;

        list_for_each_entry(props, &data->properties, list) {
                const union acpi_object *properties;
                unsigned int i;

                properties = props->properties;
                for (i = 0; i < properties->package.count; i++) {
                        const union acpi_object *propname, *propvalue;
                        const union acpi_object *property;

                        property = &properties->package.elements[i];

                        propname = &property->package.elements[0];
                        propvalue = &property->package.elements[1];

                        if (!strcmp(name, propname->string.pointer)) {
                                if (type != ACPI_TYPE_ANY &&
                                    propvalue->type != type)
                                        return -EPROTO;
                                if (obj)
                                        *obj = propvalue;

                                return 0;
                        }
                }
        }
        return -EINVAL;
}

/**
 * acpi_dev_get_property - return an ACPI property with given name.
 * @adev: ACPI device to get the property from.
 * @name: Name of the property.
 * @type: Expected property type.
 * @obj: Location to store the property value (if not %NULL).
 */
int acpi_dev_get_property(const struct acpi_device *adev, const char *name,
                          acpi_object_type type, const union acpi_object **obj)
{
        return adev ? acpi_data_get_property(&adev->data, name, type, obj) : -EINVAL;
}
EXPORT_SYMBOL_GPL(acpi_dev_get_property);

static const struct acpi_device_data *
acpi_device_data_of_node(const struct fwnode_handle *fwnode)
{
        if (is_acpi_device_node(fwnode)) {
                const struct acpi_device *adev = to_acpi_device_node(fwnode);
                return &adev->data;
        } else if (is_acpi_data_node(fwnode)) {
                const struct acpi_data_node *dn = to_acpi_data_node(fwnode);
                return &dn->data;
        }
        return NULL;
}

/**
 * acpi_node_prop_get - return an ACPI property with given name.
 * @fwnode: Firmware node to get the property from.
 * @propname: Name of the property.
 * @valptr: Location to store a pointer to the property value (if not %NULL).
 */
int acpi_node_prop_get(const struct fwnode_handle *fwnode,
                       const char *propname, void **valptr)
{
        return acpi_data_get_property(acpi_device_data_of_node(fwnode),
                                      propname, ACPI_TYPE_ANY,
                                      (const union acpi_object **)valptr);
}

/**
 * acpi_data_get_property_array - return an ACPI array property with given name
 * @adev: ACPI data object to get the property from
 * @name: Name of the property
 * @type: Expected type of array elements
 * @obj: Location to store a pointer to the property value (if not NULL)
 *
 * Look up an array property with @name and store a pointer to the resulting
 * ACPI object at the location pointed to by @obj if found.
 *
 * Callers must not attempt to free the returned objects.  Those objects will be
 * freed by the ACPI core automatically during the removal of @data.
 *
 * Return: %0 if array property (package) with @name has been found (success),
 *         %-EINVAL if the arguments are invalid,
 *         %-EINVAL if the property doesn't exist,
 *         %-EPROTO if the property is not a package or the type of its elements
 *           doesn't match @type.
 */
static int acpi_data_get_property_array(const struct acpi_device_data *data,
                                        const char *name,
                                        acpi_object_type type,
                                        const union acpi_object **obj)
{
        const union acpi_object *prop;
        int ret, i;

        ret = acpi_data_get_property(data, name, ACPI_TYPE_PACKAGE, &prop);
        if (ret)
                return ret;

        if (type != ACPI_TYPE_ANY) {
                /* Check that all elements are of correct type. */
                for (i = 0; i < prop->package.count; i++)
                        if (prop->package.elements[i].type != type)
                                return -EPROTO;
        }
        if (obj)
                *obj = prop;

        return 0;
}

static struct fwnode_handle *
acpi_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
                                 const char *childname)
{
        char name[ACPI_PATH_SEGMENT_LENGTH];
        struct fwnode_handle *child;
        struct acpi_buffer path;
        acpi_status status;

        path.length = sizeof(name);
        path.pointer = name;

        fwnode_for_each_child_node(fwnode, child) {
                if (is_acpi_data_node(child)) {
                        if (acpi_data_node_match(child, childname))
                                return child;
                        continue;
                }

                status = acpi_get_name(ACPI_HANDLE_FWNODE(child),
                                       ACPI_SINGLE_NAME, &path);
                if (ACPI_FAILURE(status))
                        break;

                if (!strncmp(name, childname, ACPI_NAMESEG_SIZE))
                        return child;
        }

        return NULL;
}

/**
 * __acpi_node_get_property_reference - returns handle to the referenced object
 * @fwnode: Firmware node to get the property from
 * @propname: Name of the property
 * @index: Index of the reference to return
 * @num_args: Maximum number of arguments after each reference
 * @args: Location to store the returned reference with optional arguments
 *
 * Find property with @name, verifify that it is a package containing at least
 * one object reference and if so, store the ACPI device object pointer to the
 * target object in @args->adev.  If the reference includes arguments, store
 * them in the @args->args[] array.
 *
 * If there's more than one reference in the property value package, @index is
 * used to select the one to return.
 *
 * It is possible to leave holes in the property value set like in the
 * example below:
 *
 * Package () {
 *     "cs-gpios",
 *     Package () {
 *        ^GPIO, 19, 0, 0,
 *        ^GPIO, 20, 0, 0,
 *        0,
 *        ^GPIO, 21, 0, 0,
 *     }
 * }
 *
 * Calling this function with index %2 or index %3 return %-ENOENT. If the
 * property does not contain any more values %-ENOENT is returned. The NULL
 * entry must be single integer and preferably contain value %0.
 *
 * Return: %0 on success, negative error code on failure.
 */
int __acpi_node_get_property_reference(const struct fwnode_handle *fwnode,
        const char *propname, size_t index, size_t num_args,
        struct fwnode_reference_args *args)
{
        const union acpi_object *element, *end;
        const union acpi_object *obj;
        const struct acpi_device_data *data;
        struct acpi_device *device;
        int ret, idx = 0;

        data = acpi_device_data_of_node(fwnode);
        if (!data)
                return -ENOENT;

        ret = acpi_data_get_property(data, propname, ACPI_TYPE_ANY, &obj);
        if (ret)
                return ret == -EINVAL ? -ENOENT : -EINVAL;

        /*
         * The simplest case is when the value is a single reference.  Just
         * return that reference then.
         */
        if (obj->type == ACPI_TYPE_LOCAL_REFERENCE) {
                if (index)
                        return -EINVAL;

                ret = acpi_bus_get_device(obj->reference.handle, &device);
                if (ret)
                        return ret == -ENODEV ? -EINVAL : ret;

                args->fwnode = acpi_fwnode_handle(device);
                args->nargs = 0;
                return 0;
        }

        /*
         * If it is not a single reference, then it is a package of
         * references followed by number of ints as follows:
         *
         *  Package () { REF, INT, REF, INT, INT }
         *
         * The index argument is then used to determine which reference
         * the caller wants (along with the arguments).
         */
        if (obj->type != ACPI_TYPE_PACKAGE)
                return -EINVAL;
        if (index >= obj->package.count)
                return -ENOENT;

        element = obj->package.elements;
        end = element + obj->package.count;

        while (element < end) {
                u32 nargs, i;

                if (element->type == ACPI_TYPE_LOCAL_REFERENCE) {
                        struct fwnode_handle *ref_fwnode;

                        ret = acpi_bus_get_device(element->reference.handle,
                                                  &device);
                        if (ret)
                                return -EINVAL;

                        nargs = 0;
                        element++;

                        /*
                         * Find the referred data extension node under the
                         * referred device node.
                         */
                        for (ref_fwnode = acpi_fwnode_handle(device);
                             element < end && element->type == ACPI_TYPE_STRING;
                             element++) {
                                ref_fwnode = acpi_fwnode_get_named_child_node(
                                        ref_fwnode, element->string.pointer);
                                if (!ref_fwnode)
                                        return -EINVAL;
                        }

                        /* assume following integer elements are all args */
                        for (i = 0; element + i < end && i < num_args; i++) {
                                int type = element[i].type;

                                if (type == ACPI_TYPE_INTEGER)
                                        nargs++;
                                else if (type == ACPI_TYPE_LOCAL_REFERENCE)
                                        break;
                                else
                                        return -EINVAL;
                        }

                        if (nargs > NR_FWNODE_REFERENCE_ARGS)
                                return -EINVAL;

                        if (idx == index) {
                                args->fwnode = ref_fwnode;
                                args->nargs = nargs;
                                for (i = 0; i < nargs; i++)
                                        args->args[i] = element[i].integer.value;

                                return 0;
                        }

                        element += nargs;
                } else if (element->type == ACPI_TYPE_INTEGER) {
                        if (idx == index)
                                return -ENOENT;
                        element++;
                } else {
                        return -EINVAL;
                }

                idx++;
        }

        return -ENOENT;
}
EXPORT_SYMBOL_GPL(__acpi_node_get_property_reference);

static int acpi_data_prop_read_single(const struct acpi_device_data *data,
                                      const char *propname,
                                      enum dev_prop_type proptype, void *val)
{
        const union acpi_object *obj;
        int ret;

        if (!val)
                return -EINVAL;

        if (proptype >= DEV_PROP_U8 && proptype <= DEV_PROP_U64) {
                ret = acpi_data_get_property(data, propname, ACPI_TYPE_INTEGER, &obj);
                if (ret)
                        return ret;

                switch (proptype) {
                case DEV_PROP_U8:
                        if (obj->integer.value > U8_MAX)
                                return -EOVERFLOW;
                        *(u8 *)val = obj->integer.value;
                        break;
                case DEV_PROP_U16:
                        if (obj->integer.value > U16_MAX)
                                return -EOVERFLOW;
                        *(u16 *)val = obj->integer.value;
                        break;
                case DEV_PROP_U32:
                        if (obj->integer.value > U32_MAX)
                                return -EOVERFLOW;
                        *(u32 *)val = obj->integer.value;
                        break;
                default:
                        *(u64 *)val = obj->integer.value;
                        break;
                }
        } else if (proptype == DEV_PROP_STRING) {
                ret = acpi_data_get_property(data, propname, ACPI_TYPE_STRING, &obj);
                if (ret)
                        return ret;

                *(char **)val = obj->string.pointer;

                return 1;
        } else {
                ret = -EINVAL;
        }
        return ret;
}

int acpi_dev_prop_read_single(struct acpi_device *adev, const char *propname,
                              enum dev_prop_type proptype, void *val)
{
        int ret;

        if (!adev)
                return -EINVAL;

        ret = acpi_data_prop_read_single(&adev->data, propname, proptype, val);
        if (ret < 0 || proptype != ACPI_TYPE_STRING)
                return ret;
        return 0;
}

static int acpi_copy_property_array_u8(const union acpi_object *items, u8 *val,
                                       size_t nval)
{
        int i;

        for (i = 0; i < nval; i++) {
                if (items[i].type != ACPI_TYPE_INTEGER)
                        return -EPROTO;
                if (items[i].integer.value > U8_MAX)
                        return -EOVERFLOW;

                val[i] = items[i].integer.value;
        }
        return 0;
}

static int acpi_copy_property_array_u16(const union acpi_object *items,
                                        u16 *val, size_t nval)
{
        int i;

        for (i = 0; i < nval; i++) {
                if (items[i].type != ACPI_TYPE_INTEGER)
                        return -EPROTO;
                if (items[i].integer.value > U16_MAX)
                        return -EOVERFLOW;

                val[i] = items[i].integer.value;
        }
        return 0;
}

static int acpi_copy_property_array_u32(const union acpi_object *items,
                                        u32 *val, size_t nval)
{
        int i;

        for (i = 0; i < nval; i++) {
                if (items[i].type != ACPI_TYPE_INTEGER)
                        return -EPROTO;
                if (items[i].integer.value > U32_MAX)
                        return -EOVERFLOW;

                val[i] = items[i].integer.value;
        }
        return 0;
}

static int acpi_copy_property_array_u64(const union acpi_object *items,
                                        u64 *val, size_t nval)
{
        int i;

        for (i = 0; i < nval; i++) {
                if (items[i].type != ACPI_TYPE_INTEGER)
                        return -EPROTO;

                val[i] = items[i].integer.value;
        }
        return 0;
}

static int acpi_copy_property_array_string(const union acpi_object *items,
                                           char **val, size_t nval)
{
        int i;

        for (i = 0; i < nval; i++) {
                if (items[i].type != ACPI_TYPE_STRING)
                        return -EPROTO;

                val[i] = items[i].string.pointer;
        }
        return nval;
}

static int acpi_data_prop_read(const struct acpi_device_data *data,
                               const char *propname,
                               enum dev_prop_type proptype,
                               void *val, size_t nval)
{
        const union acpi_object *obj;
        const union acpi_object *items;
        int ret;

        if (val && nval == 1) {
                ret = acpi_data_prop_read_single(data, propname, proptype, val);
                if (ret >= 0)
                        return ret;
        }

        ret = acpi_data_get_property_array(data, propname, ACPI_TYPE_ANY, &obj);
        if (ret)
                return ret;

        if (!val)
                return obj->package.count;

        if (proptype != DEV_PROP_STRING && nval > obj->package.count)
                return -EOVERFLOW;
        else if (nval <= 0)
                return -EINVAL;

        items = obj->package.elements;

        switch (proptype) {
        case DEV_PROP_U8:
                ret = acpi_copy_property_array_u8(items, (u8 *)val, nval);
                break;
        case DEV_PROP_U16:
                ret = acpi_copy_property_array_u16(items, (u16 *)val, nval);
                break;
        case DEV_PROP_U32:
                ret = acpi_copy_property_array_u32(items, (u32 *)val, nval);
                break;
        case DEV_PROP_U64:
                ret = acpi_copy_property_array_u64(items, (u64 *)val, nval);
                break;
        case DEV_PROP_STRING:
                ret = acpi_copy_property_array_string(
                        items, (char **)val,
                        min_t(u32, nval, obj->package.count));
                break;
        default:
                ret = -EINVAL;
                break;
        }
        return ret;
}

int acpi_dev_prop_read(const struct acpi_device *adev, const char *propname,
                       enum dev_prop_type proptype, void *val, size_t nval)
{
        return adev ? acpi_data_prop_read(&adev->data, propname, proptype, val, nval) : -EINVAL;
}

/**
 * acpi_node_prop_read - retrieve the value of an ACPI property with given name.
 * @fwnode: Firmware node to get the property from.
 * @propname: Name of the property.
 * @proptype: Expected property type.
 * @val: Location to store the property value (if not %NULL).
 * @nval: Size of the array pointed to by @val.
 *
 * If @val is %NULL, return the number of array elements comprising the value
 * of the property.  Otherwise, read at most @nval values to the array at the
 * location pointed to by @val.
 */
int acpi_node_prop_read(const struct fwnode_handle *fwnode,
                        const char *propname, enum dev_prop_type proptype,
                        void *val, size_t nval)
{
        return acpi_data_prop_read(acpi_device_data_of_node(fwnode),
                                   propname, proptype, val, nval);
}

/**
 * acpi_get_next_subnode - Return the next child node handle for a fwnode
 * @fwnode: Firmware node to find the next child node for.
 * @child: Handle to one of the device's child nodes or a null handle.
 */
struct fwnode_handle *acpi_get_next_subnode(const struct fwnode_handle *fwnode,
                                            struct fwnode_handle *child)
{
        const struct acpi_device *adev = to_acpi_device_node(fwnode);
        const struct list_head *head;
        struct list_head *next;

        if (!child || is_acpi_device_node(child)) {
                struct acpi_device *child_adev;

                if (adev)
                        head = &adev->children;
                else
                        goto nondev;

                if (list_empty(head))
                        goto nondev;

                if (child) {
                        adev = to_acpi_device_node(child);
                        next = adev->node.next;
                        if (next == head) {
                                child = NULL;
                                goto nondev;
                        }
                        child_adev = list_entry(next, struct acpi_device, node);
                } else {
                        child_adev = list_first_entry(head, struct acpi_device,
                                                      node);
                }
                return acpi_fwnode_handle(child_adev);
        }

 nondev:
        if (!child || is_acpi_data_node(child)) {
                const struct acpi_data_node *data = to_acpi_data_node(fwnode);
                struct acpi_data_node *dn;

                /*
                 * We can have a combination of device and data nodes, e.g. with
                 * hierarchical _DSD properties. Make sure the adev pointer is
                 * restored before going through data nodes, otherwise we will
                 * be looking for data_nodes below the last device found instead
                 * of the common fwnode shared by device_nodes and data_nodes.
                 */
                adev = to_acpi_device_node(fwnode);
                if (adev)
                        head = &adev->data.subnodes;
                else if (data)
                        head = &data->data.subnodes;
                else
                        return NULL;

                if (list_empty(head))
                        return NULL;

                if (child) {
                        dn = to_acpi_data_node(child);
                        next = dn->sibling.next;
                        if (next == head)
                                return NULL;

                        dn = list_entry(next, struct acpi_data_node, sibling);
                } else {
                        dn = list_first_entry(head, struct acpi_data_node, sibling);
                }
                return &dn->fwnode;
        }
        return NULL;
}

/**
 * acpi_node_get_parent - Return parent fwnode of this fwnode
 * @fwnode: Firmware node whose parent to get
 *
 * Returns parent node of an ACPI device or data firmware node or %NULL if
 * not available.
 */
struct fwnode_handle *acpi_node_get_parent(const struct fwnode_handle *fwnode)
{
        if (is_acpi_data_node(fwnode)) {
                /* All data nodes have parent pointer so just return that */
                return to_acpi_data_node(fwnode)->parent;
        } else if (is_acpi_device_node(fwnode)) {
                acpi_handle handle, parent_handle;

                handle = to_acpi_device_node(fwnode)->handle;
                if (ACPI_SUCCESS(acpi_get_parent(handle, &parent_handle))) {
                        struct acpi_device *adev;

                        if (!acpi_bus_get_device(parent_handle, &adev))
                                return acpi_fwnode_handle(adev);
                }
        }

        return NULL;
}

/*
 * Return true if the node is an ACPI graph node. Called on either ports
 * or endpoints.
 */
static bool is_acpi_graph_node(struct fwnode_handle *fwnode,
                               const char *str)
{
        unsigned int len = strlen(str);
        const char *name;

        if (!len || !is_acpi_data_node(fwnode))
                return false;

        name = to_acpi_data_node(fwnode)->name;

        return (fwnode_property_present(fwnode, "reg") &&
                !strncmp(name, str, len) && name[len] == '@') ||
                fwnode_property_present(fwnode, str);
}

/**
 * acpi_graph_get_next_endpoint - Get next endpoint ACPI firmware node
 * @fwnode: Pointer to the parent firmware node
 * @prev: Previous endpoint node or %NULL to get the first
 *
 * Looks up next endpoint ACPI firmware node below a given @fwnode. Returns
 * %NULL if there is no next endpoint or in case of error. In case of success
 * the next endpoint is returned.
 */
static struct fwnode_handle *acpi_graph_get_next_endpoint(
        const struct fwnode_handle *fwnode, struct fwnode_handle *prev)
{
        struct fwnode_handle *port = NULL;
        struct fwnode_handle *endpoint;

        if (!prev) {
                do {
                        port = fwnode_get_next_child_node(fwnode, port);
                        /*
                         * The names of the port nodes begin with "port@"
                         * followed by the number of the port node and they also
                         * have a "reg" property that also has the number of the
                         * port node. For compatibility reasons a node is also
                         * recognised as a port node from the "port" property.
                         */
                        if (is_acpi_graph_node(port, "port"))
                                break;
                } while (port);
        } else {
                port = fwnode_get_parent(prev);
        }

        if (!port)
                return NULL;

        endpoint = fwnode_get_next_child_node(port, prev);
        while (!endpoint) {
                port = fwnode_get_next_child_node(fwnode, port);
                if (!port)
                        break;
                if (is_acpi_graph_node(port, "port"))
                        endpoint = fwnode_get_next_child_node(port, NULL);
        }

        /*
         * The names of the endpoint nodes begin with "endpoint@" followed by
         * the number of the endpoint node and they also have a "reg" property
         * that also has the number of the endpoint node. For compatibility
         * reasons a node is also recognised as an endpoint node from the
         * "endpoint" property.
         */
        if (!is_acpi_graph_node(endpoint, "endpoint"))
                return NULL;

        return endpoint;
}

/**
 * acpi_graph_get_child_prop_value - Return a child with a given property value
 * @fwnode: device fwnode
 * @prop_name: The name of the property to look for
 * @val: the desired property value
 *
 * Return the port node corresponding to a given port number. Returns
 * the child node on success, NULL otherwise.
 */
static struct fwnode_handle *acpi_graph_get_child_prop_value(
        const struct fwnode_handle *fwnode, const char *prop_name,
        unsigned int val)
{
        struct fwnode_handle *child;

        fwnode_for_each_child_node(fwnode, child) {
                u32 nr;

                if (fwnode_property_read_u32(child, prop_name, &nr))
                        continue;

                if (val == nr)
                        return child;
        }

        return NULL;
}


/**
 * acpi_graph_get_remote_enpoint - Parses and returns remote end of an endpoint
 * @fwnode: Endpoint firmware node pointing to a remote device
 * @endpoint: Firmware node of remote endpoint is filled here if not %NULL
 *
 * Returns the remote endpoint corresponding to @__fwnode. NULL on error.
 */
static struct fwnode_handle *
acpi_graph_get_remote_endpoint(const struct fwnode_handle *__fwnode)
{
        struct fwnode_handle *fwnode;
        unsigned int port_nr, endpoint_nr;
        struct fwnode_reference_args args;
        int ret;

        memset(&args, 0, sizeof(args));
        ret = acpi_node_get_property_reference(__fwnode, "remote-endpoint", 0,
                                               &args);
        if (ret)
                return NULL;

        /* Direct endpoint reference? */
        if (!is_acpi_device_node(args.fwnode))
                return args.nargs ? NULL : args.fwnode;

        /*
         * Always require two arguments with the reference: port and
         * endpoint indices.
         */
        if (args.nargs != 2)
                return NULL;

        fwnode = args.fwnode;
        port_nr = args.args[0];
        endpoint_nr = args.args[1];

        fwnode = acpi_graph_get_child_prop_value(fwnode, "port", port_nr);

        return acpi_graph_get_child_prop_value(fwnode, "endpoint", endpoint_nr);
}

static bool acpi_fwnode_device_is_available(const struct fwnode_handle *fwnode)
{
        if (!is_acpi_device_node(fwnode))
                return false;

        return acpi_device_is_present(to_acpi_device_node(fwnode));
}

static bool acpi_fwnode_property_present(const struct fwnode_handle *fwnode,
                                         const char *propname)
{
        return !acpi_node_prop_get(fwnode, propname, NULL);
}

static int
acpi_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
                                    const char *propname,
                                    unsigned int elem_size, void *val,
                                    size_t nval)
{
        enum dev_prop_type type;

        switch (elem_size) {
        case sizeof(u8):
                type = DEV_PROP_U8;
                break;
        case sizeof(u16):
                type = DEV_PROP_U16;
                break;
        case sizeof(u32):
                type = DEV_PROP_U32;
                break;
        case sizeof(u64):
                type = DEV_PROP_U64;
                break;
        default:
                return -ENXIO;
        }

        return acpi_node_prop_read(fwnode, propname, type, val, nval);
}

static int
acpi_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
                                       const char *propname, const char **val,
                                       size_t nval)
{
        return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
                                   val, nval);
}

static int
acpi_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
                               const char *prop, const char *nargs_prop,
                               unsigned int args_count, unsigned int index,
                               struct fwnode_reference_args *args)
{
        return __acpi_node_get_property_reference(fwnode, prop, index,
                                                  args_count, args);
}

static struct fwnode_handle *
acpi_fwnode_get_parent(struct fwnode_handle *fwnode)
{
        return acpi_node_get_parent(fwnode);
}

static int acpi_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
                                            struct fwnode_endpoint *endpoint)
{
        struct fwnode_handle *port_fwnode = fwnode_get_parent(fwnode);

        endpoint->local_fwnode = fwnode;

        if (fwnode_property_read_u32(port_fwnode, "reg", &endpoint->port))
                fwnode_property_read_u32(port_fwnode, "port", &endpoint->port);
        if (fwnode_property_read_u32(fwnode, "reg", &endpoint->id))
                fwnode_property_read_u32(fwnode, "endpoint", &endpoint->id);

        return 0;
}

static const void *
acpi_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
                                  const struct device *dev)
{
        return acpi_device_get_match_data(dev);
}

#define DECLARE_ACPI_FWNODE_OPS(ops) \
        const struct fwnode_operations ops = {                          \
                .device_is_available = acpi_fwnode_device_is_available, \
                .device_get_match_data = acpi_fwnode_device_get_match_data, \
                .property_present = acpi_fwnode_property_present,       \
                .property_read_int_array =                              \
                        acpi_fwnode_property_read_int_array,            \
                .property_read_string_array =                           \
                        acpi_fwnode_property_read_string_array,         \
                .get_parent = acpi_node_get_parent,                     \
                .get_next_child_node = acpi_get_next_subnode,           \
                .get_named_child_node = acpi_fwnode_get_named_child_node, \
                .get_reference_args = acpi_fwnode_get_reference_args,   \
                .graph_get_next_endpoint =                              \
                        acpi_graph_get_next_endpoint,                   \
                .graph_get_remote_endpoint =                            \
                        acpi_graph_get_remote_endpoint,                 \
                .graph_get_port_parent = acpi_fwnode_get_parent,        \
                .graph_parse_endpoint = acpi_fwnode_graph_parse_endpoint, \
        };                                                              \
        EXPORT_SYMBOL_GPL(ops)

DECLARE_ACPI_FWNODE_OPS(acpi_device_fwnode_ops);
DECLARE_ACPI_FWNODE_OPS(acpi_data_fwnode_ops);
const struct fwnode_operations acpi_static_fwnode_ops;

bool is_acpi_device_node(const struct fwnode_handle *fwnode)
{
        return !IS_ERR_OR_NULL(fwnode) &&
                fwnode->ops == &acpi_device_fwnode_ops;
}
EXPORT_SYMBOL(is_acpi_device_node);

bool is_acpi_data_node(const struct fwnode_handle *fwnode)
{
        return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &acpi_data_fwnode_ops;
}
EXPORT_SYMBOL(is_acpi_data_node);