drm/nouveau: fix kernel-doc comments

[drm/drm-misc.git] / drivers / acpi / scan.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * scan.c - support for transforming the ACPI namespace into individual objects
 */

#define pr_fmt(fmt) "ACPI: " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/acpi_iort.h>
#include <linux/acpi_viot.h>
#include <linux/iommu.h>
#include <linux/signal.h>
#include <linux/kthread.h>
#include <linux/dmi.h>
#include <linux/dma-map-ops.h>
#include <linux/platform_data/x86/apple.h>
#include <linux/pgtable.h>
#include <linux/crc32.h>
#include <linux/dma-direct.h>

#include "internal.h"
#include "sleep.h"

#define ACPI_BUS_CLASS                  "system_bus"
#define ACPI_BUS_HID                    "LNXSYBUS"
#define ACPI_BUS_DEVICE_NAME            "System Bus"

#define INVALID_ACPI_HANDLE     ((acpi_handle)ZERO_PAGE(0))

static const char *dummy_hid = "device";

static LIST_HEAD(acpi_dep_list);
static DEFINE_MUTEX(acpi_dep_list_lock);
LIST_HEAD(acpi_bus_id_list);
static DEFINE_MUTEX(acpi_scan_lock);
static LIST_HEAD(acpi_scan_handlers_list);
DEFINE_MUTEX(acpi_device_lock);
LIST_HEAD(acpi_wakeup_device_list);
static DEFINE_MUTEX(acpi_hp_context_lock);

/*
 * The UART device described by the SPCR table is the only object which needs
 * special-casing. Everything else is covered by ACPI namespace paths in STAO
 * table.
 */
static u64 spcr_uart_addr;

void acpi_scan_lock_acquire(void)
{
        mutex_lock(&acpi_scan_lock);
}
EXPORT_SYMBOL_GPL(acpi_scan_lock_acquire);

void acpi_scan_lock_release(void)
{
        mutex_unlock(&acpi_scan_lock);
}
EXPORT_SYMBOL_GPL(acpi_scan_lock_release);

void acpi_lock_hp_context(void)
{
        mutex_lock(&acpi_hp_context_lock);
}

void acpi_unlock_hp_context(void)
{
        mutex_unlock(&acpi_hp_context_lock);
}

void acpi_initialize_hp_context(struct acpi_device *adev,
                                struct acpi_hotplug_context *hp,
                                acpi_hp_notify notify, acpi_hp_uevent uevent)
{
        acpi_lock_hp_context();
        hp->notify = notify;
        hp->uevent = uevent;
        acpi_set_hp_context(adev, hp);
        acpi_unlock_hp_context();
}
EXPORT_SYMBOL_GPL(acpi_initialize_hp_context);

int acpi_scan_add_handler(struct acpi_scan_handler *handler)
{
        if (!handler)
                return -EINVAL;

        list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
        return 0;
}

int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
                                       const char *hotplug_profile_name)
{
        int error;

        error = acpi_scan_add_handler(handler);
        if (error)
                return error;

        acpi_sysfs_add_hotplug_profile(&handler->hotplug, hotplug_profile_name);
        return 0;
}

bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
{
        struct acpi_device_physical_node *pn;
        bool offline = true;
        char *envp[] = { "EVENT=offline", NULL };

        /*
         * acpi_container_offline() calls this for all of the container's
         * children under the container's physical_node_lock lock.
         */
        mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);

        list_for_each_entry(pn, &adev->physical_node_list, node)
                if (device_supports_offline(pn->dev) && !pn->dev->offline) {
                        if (uevent)
                                kobject_uevent_env(&pn->dev->kobj, KOBJ_CHANGE, envp);

                        offline = false;
                        break;
                }

        mutex_unlock(&adev->physical_node_lock);
        return offline;
}

static acpi_status acpi_bus_offline(acpi_handle handle, u32 lvl, void *data,
                                    void **ret_p)
{
        struct acpi_device *device = acpi_fetch_acpi_dev(handle);
        struct acpi_device_physical_node *pn;
        bool second_pass = (bool)data;
        acpi_status status = AE_OK;

        if (!device)
                return AE_OK;

        if (device->handler && !device->handler->hotplug.enabled) {
                *ret_p = &device->dev;
                return AE_SUPPORT;
        }

        mutex_lock(&device->physical_node_lock);

        list_for_each_entry(pn, &device->physical_node_list, node) {
                int ret;

                if (second_pass) {
                        /* Skip devices offlined by the first pass. */
                        if (pn->put_online)
                                continue;
                } else {
                        pn->put_online = false;
                }
                ret = device_offline(pn->dev);
                if (ret >= 0) {
                        pn->put_online = !ret;
                } else {
                        *ret_p = pn->dev;
                        if (second_pass) {
                                status = AE_ERROR;
                                break;
                        }
                }
        }

        mutex_unlock(&device->physical_node_lock);

        return status;
}

static acpi_status acpi_bus_online(acpi_handle handle, u32 lvl, void *data,
                                   void **ret_p)
{
        struct acpi_device *device = acpi_fetch_acpi_dev(handle);
        struct acpi_device_physical_node *pn;

        if (!device)
                return AE_OK;

        mutex_lock(&device->physical_node_lock);

        list_for_each_entry(pn, &device->physical_node_list, node)
                if (pn->put_online) {
                        device_online(pn->dev);
                        pn->put_online = false;
                }

        mutex_unlock(&device->physical_node_lock);

        return AE_OK;
}

static int acpi_scan_try_to_offline(struct acpi_device *device)
{
        acpi_handle handle = device->handle;
        struct device *errdev = NULL;
        acpi_status status;

        /*
         * Carry out two passes here and ignore errors in the first pass,
         * because if the devices in question are memory blocks and
         * CONFIG_MEMCG is set, one of the blocks may hold data structures
         * that the other blocks depend on, but it is not known in advance which
         * block holds them.
         *
         * If the first pass is successful, the second one isn't needed, though.
         */
        status = acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                                     NULL, acpi_bus_offline, (void *)false,
                                     (void **)&errdev);
        if (status == AE_SUPPORT) {
                dev_warn(errdev, "Offline disabled.\n");
                acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                                    acpi_bus_online, NULL, NULL, NULL);
                return -EPERM;
        }
        acpi_bus_offline(handle, 0, (void *)false, (void **)&errdev);
        if (errdev) {
                errdev = NULL;
                acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                                    NULL, acpi_bus_offline, (void *)true,
                                    (void **)&errdev);
                if (!errdev)
                        acpi_bus_offline(handle, 0, (void *)true,
                                         (void **)&errdev);

                if (errdev) {
                        dev_warn(errdev, "Offline failed.\n");
                        acpi_bus_online(handle, 0, NULL, NULL);
                        acpi_walk_namespace(ACPI_TYPE_ANY, handle,
                                            ACPI_UINT32_MAX, acpi_bus_online,
                                            NULL, NULL, NULL);
                        return -EBUSY;
                }
        }
        return 0;
}

#define ACPI_SCAN_CHECK_FLAG_STATUS     BIT(0)
#define ACPI_SCAN_CHECK_FLAG_EJECT      BIT(1)

static int acpi_scan_check_and_detach(struct acpi_device *adev, void *p)
{
        struct acpi_scan_handler *handler = adev->handler;
        uintptr_t flags = (uintptr_t)p;

        acpi_dev_for_each_child_reverse(adev, acpi_scan_check_and_detach, p);

        if (flags & ACPI_SCAN_CHECK_FLAG_STATUS) {
                acpi_bus_get_status(adev);
                /*
                 * Skip devices that are still there and take the enabled
                 * flag into account.
                 */
                if (acpi_device_is_enabled(adev))
                        return 0;

                /* Skip device that have not been enumerated. */
                if (!acpi_device_enumerated(adev)) {
                        dev_dbg(&adev->dev, "Still not enumerated\n");
                        return 0;
                }
        }

        adev->flags.match_driver = false;
        if (handler) {
                if (handler->detach)
                        handler->detach(adev);
        } else {
                device_release_driver(&adev->dev);
        }
        /*
         * Most likely, the device is going away, so put it into D3cold before
         * that.
         */
        acpi_device_set_power(adev, ACPI_STATE_D3_COLD);
        adev->flags.initialized = false;

        /* For eject this is deferred to acpi_bus_post_eject() */
        if (!(flags & ACPI_SCAN_CHECK_FLAG_EJECT)) {
                adev->handler = NULL;
                acpi_device_clear_enumerated(adev);
        }
        return 0;
}

static int acpi_bus_post_eject(struct acpi_device *adev, void *not_used)
{
        struct acpi_scan_handler *handler = adev->handler;

        acpi_dev_for_each_child_reverse(adev, acpi_bus_post_eject, NULL);

        if (handler) {
                if (handler->post_eject)
                        handler->post_eject(adev);

                adev->handler = NULL;
        }

        acpi_device_clear_enumerated(adev);

        return 0;
}

static void acpi_scan_check_subtree(struct acpi_device *adev)
{
        uintptr_t flags = ACPI_SCAN_CHECK_FLAG_STATUS;

        acpi_scan_check_and_detach(adev, (void *)flags);
}

static int acpi_scan_hot_remove(struct acpi_device *device)
{
        acpi_handle handle = device->handle;
        unsigned long long sta;
        acpi_status status;
        uintptr_t flags = ACPI_SCAN_CHECK_FLAG_EJECT;

        if (device->handler && device->handler->hotplug.demand_offline) {
                if (!acpi_scan_is_offline(device, true))
                        return -EBUSY;
        } else {
                int error = acpi_scan_try_to_offline(device);
                if (error)
                        return error;
        }

        acpi_handle_debug(handle, "Ejecting\n");

        acpi_scan_check_and_detach(device, (void *)flags);

        acpi_evaluate_lck(handle, 0);
        /*
         * TBD: _EJD support.
         */
        status = acpi_evaluate_ej0(handle);
        if (status == AE_NOT_FOUND)
                return -ENODEV;
        else if (ACPI_FAILURE(status))
                return -EIO;

        /*
         * Verify if eject was indeed successful.  If not, log an error
         * message.  No need to call _OST since _EJ0 call was made OK.
         */
        status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
        if (ACPI_FAILURE(status)) {
                acpi_handle_warn(handle,
                        "Status check after eject failed (0x%x)\n", status);
        } else if (sta & ACPI_STA_DEVICE_ENABLED) {
                acpi_handle_warn(handle,
                        "Eject incomplete - status 0x%llx\n", sta);
        } else {
                acpi_bus_post_eject(device, NULL);
        }

        return 0;
}

static int acpi_scan_rescan_bus(struct acpi_device *adev)
{
        struct acpi_scan_handler *handler = adev->handler;
        int ret;

        if (handler && handler->hotplug.scan_dependent)
                ret = handler->hotplug.scan_dependent(adev);
        else
                ret = acpi_bus_scan(adev->handle);

        if (ret)
                dev_info(&adev->dev, "Namespace scan failure\n");

        return ret;
}

static int acpi_scan_device_check(struct acpi_device *adev)
{
        struct acpi_device *parent;

        acpi_scan_check_subtree(adev);

        if (!acpi_device_is_present(adev))
                return 0;

        /*
         * This function is only called for device objects for which matching
         * scan handlers exist.  The only situation in which the scan handler
         * is not attached to this device object yet is when the device has
         * just appeared (either it wasn't present at all before or it was
         * removed and then added again).
         */
        if (adev->handler) {
                dev_dbg(&adev->dev, "Already enumerated\n");
                return 0;
        }

        parent = acpi_dev_parent(adev);
        if (!parent)
                parent = adev;

        return acpi_scan_rescan_bus(parent);
}

static int acpi_scan_bus_check(struct acpi_device *adev)
{
        acpi_scan_check_subtree(adev);

        return acpi_scan_rescan_bus(adev);
}

static int acpi_generic_hotplug_event(struct acpi_device *adev, u32 type)
{
        switch (type) {
        case ACPI_NOTIFY_BUS_CHECK:
                return acpi_scan_bus_check(adev);
        case ACPI_NOTIFY_DEVICE_CHECK:
                return acpi_scan_device_check(adev);
        case ACPI_NOTIFY_EJECT_REQUEST:
        case ACPI_OST_EC_OSPM_EJECT:
                if (adev->handler && !adev->handler->hotplug.enabled) {
                        dev_info(&adev->dev, "Eject disabled\n");
                        return -EPERM;
                }
                acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_EJECT_REQUEST,
                                  ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
                return acpi_scan_hot_remove(adev);
        }
        return -EINVAL;
}

void acpi_device_hotplug(struct acpi_device *adev, u32 src)
{
        u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
        int error = -ENODEV;

        lock_device_hotplug();
        mutex_lock(&acpi_scan_lock);

        /*
         * The device object's ACPI handle cannot become invalid as long as we
         * are holding acpi_scan_lock, but it might have become invalid before
         * that lock was acquired.
         */
        if (adev->handle == INVALID_ACPI_HANDLE)
                goto err_out;

        if (adev->flags.is_dock_station) {
                error = dock_notify(adev, src);
        } else if (adev->flags.hotplug_notify) {
                error = acpi_generic_hotplug_event(adev, src);
        } else {
                acpi_hp_notify notify;

                acpi_lock_hp_context();
                notify = adev->hp ? adev->hp->notify : NULL;
                acpi_unlock_hp_context();
                /*
                 * There may be additional notify handlers for device objects
                 * without the .event() callback, so ignore them here.
                 */
                if (notify)
                        error = notify(adev, src);
                else
                        goto out;
        }
        switch (error) {
        case 0:
                ost_code = ACPI_OST_SC_SUCCESS;
                break;
        case -EPERM:
                ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
                break;
        case -EBUSY:
                ost_code = ACPI_OST_SC_DEVICE_BUSY;
                break;
        default:
                ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
                break;
        }

 err_out:
        acpi_evaluate_ost(adev->handle, src, ost_code, NULL);

 out:
        acpi_put_acpi_dev(adev);
        mutex_unlock(&acpi_scan_lock);
        unlock_device_hotplug();
}

static void acpi_free_power_resources_lists(struct acpi_device *device)
{
        int i;

        if (device->wakeup.flags.valid)
                acpi_power_resources_list_free(&device->wakeup.resources);

        if (!device->power.flags.power_resources)
                return;

        for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++) {
                struct acpi_device_power_state *ps = &device->power.states[i];
                acpi_power_resources_list_free(&ps->resources);
        }
}

static void acpi_device_release(struct device *dev)
{
        struct acpi_device *acpi_dev = to_acpi_device(dev);

        acpi_free_properties(acpi_dev);
        acpi_free_pnp_ids(&acpi_dev->pnp);
        acpi_free_power_resources_lists(acpi_dev);
        kfree(acpi_dev);
}

static void acpi_device_del(struct acpi_device *device)
{
        struct acpi_device_bus_id *acpi_device_bus_id;

        mutex_lock(&acpi_device_lock);

        list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
                if (!strcmp(acpi_device_bus_id->bus_id,
                            acpi_device_hid(device))) {
                        ida_free(&acpi_device_bus_id->instance_ida,
                                 device->pnp.instance_no);
                        if (ida_is_empty(&acpi_device_bus_id->instance_ida)) {
                                list_del(&acpi_device_bus_id->node);
                                kfree_const(acpi_device_bus_id->bus_id);
                                kfree(acpi_device_bus_id);
                        }
                        break;
                }

        list_del(&device->wakeup_list);

        mutex_unlock(&acpi_device_lock);

        acpi_power_add_remove_device(device, false);
        acpi_device_remove_files(device);
        if (device->remove)
                device->remove(device);

        device_del(&device->dev);
}

static BLOCKING_NOTIFIER_HEAD(acpi_reconfig_chain);

static LIST_HEAD(acpi_device_del_list);
static DEFINE_MUTEX(acpi_device_del_lock);

static void acpi_device_del_work_fn(struct work_struct *work_not_used)
{
        for (;;) {
                struct acpi_device *adev;

                mutex_lock(&acpi_device_del_lock);

                if (list_empty(&acpi_device_del_list)) {
                        mutex_unlock(&acpi_device_del_lock);
                        break;
                }
                adev = list_first_entry(&acpi_device_del_list,
                                        struct acpi_device, del_list);
                list_del(&adev->del_list);

                mutex_unlock(&acpi_device_del_lock);

                blocking_notifier_call_chain(&acpi_reconfig_chain,
                                             ACPI_RECONFIG_DEVICE_REMOVE, adev);

                acpi_device_del(adev);
                /*
                 * Drop references to all power resources that might have been
                 * used by the device.
                 */
                acpi_power_transition(adev, ACPI_STATE_D3_COLD);
                acpi_dev_put(adev);
        }
}

/**
 * acpi_scan_drop_device - Drop an ACPI device object.
 * @handle: Handle of an ACPI namespace node, not used.
 * @context: Address of the ACPI device object to drop.
 *
 * This is invoked by acpi_ns_delete_node() during the removal of the ACPI
 * namespace node the device object pointed to by @context is attached to.
 *
 * The unregistration is carried out asynchronously to avoid running
 * acpi_device_del() under the ACPICA's namespace mutex and the list is used to
 * ensure the correct ordering (the device objects must be unregistered in the
 * same order in which the corresponding namespace nodes are deleted).
 */
static void acpi_scan_drop_device(acpi_handle handle, void *context)
{
        static DECLARE_WORK(work, acpi_device_del_work_fn);
        struct acpi_device *adev = context;

        mutex_lock(&acpi_device_del_lock);

        /*
         * Use the ACPI hotplug workqueue which is ordered, so this work item
         * won't run after any hotplug work items submitted subsequently.  That
         * prevents attempts to register device objects identical to those being
         * deleted from happening concurrently (such attempts result from
         * hotplug events handled via the ACPI hotplug workqueue).  It also will
         * run after all of the work items submitted previously, which helps
         * those work items to ensure that they are not accessing stale device
         * objects.
         */
        if (list_empty(&acpi_device_del_list))
                acpi_queue_hotplug_work(&work);

        list_add_tail(&adev->del_list, &acpi_device_del_list);
        /* Make acpi_ns_validate_handle() return NULL for this handle. */
        adev->handle = INVALID_ACPI_HANDLE;

        mutex_unlock(&acpi_device_del_lock);
}

static struct acpi_device *handle_to_device(acpi_handle handle,
                                            void (*callback)(void *))
{
        struct acpi_device *adev = NULL;
        acpi_status status;

        status = acpi_get_data_full(handle, acpi_scan_drop_device,
                                    (void **)&adev, callback);
        if (ACPI_FAILURE(status) || !adev) {
                acpi_handle_debug(handle, "No context!\n");
                return NULL;
        }
        return adev;
}

/**
 * acpi_fetch_acpi_dev - Retrieve ACPI device object.
 * @handle: ACPI handle associated with the requested ACPI device object.
 *
 * Return a pointer to the ACPI device object associated with @handle, if
 * present, or NULL otherwise.
 */
struct acpi_device *acpi_fetch_acpi_dev(acpi_handle handle)
{
        return handle_to_device(handle, NULL);
}
EXPORT_SYMBOL_GPL(acpi_fetch_acpi_dev);

static void get_acpi_device(void *dev)
{
        acpi_dev_get(dev);
}

/**
 * acpi_get_acpi_dev - Retrieve ACPI device object and reference count it.
 * @handle: ACPI handle associated with the requested ACPI device object.
 *
 * Return a pointer to the ACPI device object associated with @handle and bump
 * up that object's reference counter (under the ACPI Namespace lock), if
 * present, or return NULL otherwise.
 *
 * The ACPI device object reference acquired by this function needs to be
 * dropped via acpi_dev_put().
 */
struct acpi_device *acpi_get_acpi_dev(acpi_handle handle)
{
        return handle_to_device(handle, get_acpi_device);
}
EXPORT_SYMBOL_GPL(acpi_get_acpi_dev);

static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
{
        struct acpi_device_bus_id *acpi_device_bus_id;

        /* Find suitable bus_id and instance number in acpi_bus_id_list. */
        list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) {
                if (!strcmp(acpi_device_bus_id->bus_id, dev_id))
                        return acpi_device_bus_id;
        }
        return NULL;
}

static int acpi_device_set_name(struct acpi_device *device,
                                struct acpi_device_bus_id *acpi_device_bus_id)
{
        struct ida *instance_ida = &acpi_device_bus_id->instance_ida;
        int result;

        result = ida_alloc(instance_ida, GFP_KERNEL);
        if (result < 0)
                return result;

        device->pnp.instance_no = result;
        dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, result);
        return 0;
}

int acpi_tie_acpi_dev(struct acpi_device *adev)
{
        acpi_handle handle = adev->handle;
        acpi_status status;

        if (!handle)
                return 0;

        status = acpi_attach_data(handle, acpi_scan_drop_device, adev);
        if (ACPI_FAILURE(status)) {
                acpi_handle_err(handle, "Unable to attach device data\n");
                return -ENODEV;
        }

        return 0;
}

static void acpi_store_pld_crc(struct acpi_device *adev)
{
        struct acpi_pld_info *pld;
        acpi_status status;

        status = acpi_get_physical_device_location(adev->handle, &pld);
        if (ACPI_FAILURE(status))
                return;

        adev->pld_crc = crc32(~0, pld, sizeof(*pld));
        ACPI_FREE(pld);
}

int acpi_device_add(struct acpi_device *device)
{
        struct acpi_device_bus_id *acpi_device_bus_id;
        int result;

        /*
         * Linkage
         * -------
         * Link this device to its parent and siblings.
         */
        INIT_LIST_HEAD(&device->wakeup_list);
        INIT_LIST_HEAD(&device->physical_node_list);
        INIT_LIST_HEAD(&device->del_list);
        mutex_init(&device->physical_node_lock);

        mutex_lock(&acpi_device_lock);

        acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device));
        if (acpi_device_bus_id) {
                result = acpi_device_set_name(device, acpi_device_bus_id);
                if (result)
                        goto err_unlock;
        } else {
                acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id),
                                             GFP_KERNEL);
                if (!acpi_device_bus_id) {
                        result = -ENOMEM;
                        goto err_unlock;
                }
                acpi_device_bus_id->bus_id =
                        kstrdup_const(acpi_device_hid(device), GFP_KERNEL);
                if (!acpi_device_bus_id->bus_id) {
                        kfree(acpi_device_bus_id);
                        result = -ENOMEM;
                        goto err_unlock;
                }

                ida_init(&acpi_device_bus_id->instance_ida);

                result = acpi_device_set_name(device, acpi_device_bus_id);
                if (result) {
                        kfree_const(acpi_device_bus_id->bus_id);
                        kfree(acpi_device_bus_id);
                        goto err_unlock;
                }

                list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list);
        }

        if (device->wakeup.flags.valid)
                list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);

        acpi_store_pld_crc(device);

        mutex_unlock(&acpi_device_lock);

        result = device_add(&device->dev);
        if (result) {
                dev_err(&device->dev, "Error registering device\n");
                goto err;
        }

        acpi_device_setup_files(device);

        return 0;

err:
        mutex_lock(&acpi_device_lock);

        list_del(&device->wakeup_list);

err_unlock:
        mutex_unlock(&acpi_device_lock);

        acpi_detach_data(device->handle, acpi_scan_drop_device);

        return result;
}

/* --------------------------------------------------------------------------
                                 Device Enumeration
   -------------------------------------------------------------------------- */
static bool acpi_info_matches_ids(struct acpi_device_info *info,
                                  const char * const ids[])
{
        struct acpi_pnp_device_id_list *cid_list = NULL;
        int i, index;

        if (!(info->valid & ACPI_VALID_HID))
                return false;

        index = match_string(ids, -1, info->hardware_id.string);
        if (index >= 0)
                return true;

        if (info->valid & ACPI_VALID_CID)
                cid_list = &info->compatible_id_list;

        if (!cid_list)
                return false;

        for (i = 0; i < cid_list->count; i++) {
                index = match_string(ids, -1, cid_list->ids[i].string);
                if (index >= 0)
                        return true;
        }

        return false;
}

/* List of HIDs for which we ignore matching ACPI devices, when checking _DEP lists. */
static const char * const acpi_ignore_dep_ids[] = {
        "PNP0D80", /* Windows-compatible System Power Management Controller */
        "INT33BD", /* Intel Baytrail Mailbox Device */
        "LATT2021", /* Lattice FW Update Client Driver */
        NULL
};

/* List of HIDs for which we honor deps of matching ACPI devs, when checking _DEP lists. */
static const char * const acpi_honor_dep_ids[] = {
        "INT3472", /* Camera sensor PMIC / clk and regulator info */
        "INTC1059", /* IVSC (TGL) driver must be loaded to allow i2c access to camera sensors */
        "INTC1095", /* IVSC (ADL) driver must be loaded to allow i2c access to camera sensors */
        "INTC100A", /* IVSC (RPL) driver must be loaded to allow i2c access to camera sensors */
        "INTC10CF", /* IVSC (MTL) driver must be loaded to allow i2c access to camera sensors */
        "RSCV0001", /* RISC-V PLIC */
        "RSCV0002", /* RISC-V APLIC */
        "PNP0C0F",  /* PCI Link Device */
        NULL
};

static struct acpi_device *acpi_find_parent_acpi_dev(acpi_handle handle)
{
        struct acpi_device *adev;

        /*
         * Fixed hardware devices do not appear in the namespace and do not
         * have handles, but we fabricate acpi_devices for them, so we have
         * to deal with them specially.
         */
        if (!handle)
                return acpi_root;

        do {
                acpi_status status;

                status = acpi_get_parent(handle, &handle);
                if (ACPI_FAILURE(status)) {
                        if (status != AE_NULL_ENTRY)
                                return acpi_root;

                        return NULL;
                }
                adev = acpi_fetch_acpi_dev(handle);
        } while (!adev);
        return adev;
}

acpi_status
acpi_bus_get_ejd(acpi_handle handle, acpi_handle *ejd)
{
        acpi_status status;
        acpi_handle tmp;
        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
        union acpi_object *obj;

        status = acpi_get_handle(handle, "_EJD", &tmp);
        if (ACPI_FAILURE(status))
                return status;

        status = acpi_evaluate_object(handle, "_EJD", NULL, &buffer);
        if (ACPI_SUCCESS(status)) {
                obj = buffer.pointer;
                status = acpi_get_handle(ACPI_ROOT_OBJECT, obj->string.pointer,
                                         ejd);
                kfree(buffer.pointer);
        }
        return status;
}
EXPORT_SYMBOL_GPL(acpi_bus_get_ejd);

static int acpi_bus_extract_wakeup_device_power_package(struct acpi_device *dev)
{
        acpi_handle handle = dev->handle;
        struct acpi_device_wakeup *wakeup = &dev->wakeup;
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *package = NULL;
        union acpi_object *element = NULL;
        acpi_status status;
        int err = -ENODATA;

        INIT_LIST_HEAD(&wakeup->resources);

        /* _PRW */
        status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
        if (ACPI_FAILURE(status)) {
                acpi_handle_info(handle, "_PRW evaluation failed: %s\n",
                                 acpi_format_exception(status));
                return err;
        }

        package = (union acpi_object *)buffer.pointer;

        if (!package || package->package.count < 2)
                goto out;

        element = &(package->package.elements[0]);
        if (!element)
                goto out;

        if (element->type == ACPI_TYPE_PACKAGE) {
                if ((element->package.count < 2) ||
                    (element->package.elements[0].type !=
                     ACPI_TYPE_LOCAL_REFERENCE)
                    || (element->package.elements[1].type != ACPI_TYPE_INTEGER))
                        goto out;

                wakeup->gpe_device =
                    element->package.elements[0].reference.handle;
                wakeup->gpe_number =
                    (u32) element->package.elements[1].integer.value;
        } else if (element->type == ACPI_TYPE_INTEGER) {
                wakeup->gpe_device = NULL;
                wakeup->gpe_number = element->integer.value;
        } else {
                goto out;
        }

        element = &(package->package.elements[1]);
        if (element->type != ACPI_TYPE_INTEGER)
                goto out;

        wakeup->sleep_state = element->integer.value;

        err = acpi_extract_power_resources(package, 2, &wakeup->resources);
        if (err)
                goto out;

        if (!list_empty(&wakeup->resources)) {
                int sleep_state;

                err = acpi_power_wakeup_list_init(&wakeup->resources,
                                                  &sleep_state);
                if (err) {
                        acpi_handle_warn(handle, "Retrieving current states "
                                         "of wakeup power resources failed\n");
                        acpi_power_resources_list_free(&wakeup->resources);
                        goto out;
                }
                if (sleep_state < wakeup->sleep_state) {
                        acpi_handle_warn(handle, "Overriding _PRW sleep state "
                                         "(S%d) by S%d from power resources\n",
                                         (int)wakeup->sleep_state, sleep_state);
                        wakeup->sleep_state = sleep_state;
                }
        }

 out:
        kfree(buffer.pointer);
        return err;
}

/* Do not use a button for S5 wakeup */
#define ACPI_AVOID_WAKE_FROM_S5         BIT(0)

static bool acpi_wakeup_gpe_init(struct acpi_device *device)
{
        static const struct acpi_device_id button_device_ids[] = {
                {"PNP0C0C", 0},                         /* Power button */
                {"PNP0C0D", ACPI_AVOID_WAKE_FROM_S5},   /* Lid */
                {"PNP0C0E", ACPI_AVOID_WAKE_FROM_S5},   /* Sleep button */
                {"", 0},
        };
        struct acpi_device_wakeup *wakeup = &device->wakeup;
        const struct acpi_device_id *match;
        acpi_status status;

        wakeup->flags.notifier_present = 0;

        /* Power button, Lid switch always enable wakeup */
        match = acpi_match_acpi_device(button_device_ids, device);
        if (match) {
                if ((match->driver_data & ACPI_AVOID_WAKE_FROM_S5) &&
                    wakeup->sleep_state == ACPI_STATE_S5)
                        wakeup->sleep_state = ACPI_STATE_S4;
                acpi_mark_gpe_for_wake(wakeup->gpe_device, wakeup->gpe_number);
                device_set_wakeup_capable(&device->dev, true);
                return true;
        }

        status = acpi_setup_gpe_for_wake(device->handle, wakeup->gpe_device,
                                         wakeup->gpe_number);
        return ACPI_SUCCESS(status);
}

static void acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
{
        int err;

        /* Presence of _PRW indicates wake capable */
        if (!acpi_has_method(device->handle, "_PRW"))
                return;

        err = acpi_bus_extract_wakeup_device_power_package(device);
        if (err) {
                dev_err(&device->dev, "Unable to extract wakeup power resources");
                return;
        }

        device->wakeup.flags.valid = acpi_wakeup_gpe_init(device);
        device->wakeup.prepare_count = 0;
        /*
         * Call _PSW/_DSW object to disable its ability to wake the sleeping
         * system for the ACPI device with the _PRW object.
         * The _PSW object is deprecated in ACPI 3.0 and is replaced by _DSW.
         * So it is necessary to call _DSW object first. Only when it is not
         * present will the _PSW object used.
         */
        err = acpi_device_sleep_wake(device, 0, 0, 0);
        if (err)
                pr_debug("error in _DSW or _PSW evaluation\n");
}

static void acpi_bus_init_power_state(struct acpi_device *device, int state)
{
        struct acpi_device_power_state *ps = &device->power.states[state];
        char pathname[5] = { '_', 'P', 'R', '0' + state, '\0' };
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        acpi_status status;

        INIT_LIST_HEAD(&ps->resources);

        /* Evaluate "_PRx" to get referenced power resources */
        status = acpi_evaluate_object(device->handle, pathname, NULL, &buffer);
        if (ACPI_SUCCESS(status)) {
                union acpi_object *package = buffer.pointer;

                if (buffer.length && package
                    && package->type == ACPI_TYPE_PACKAGE
                    && package->package.count)
                        acpi_extract_power_resources(package, 0, &ps->resources);

                ACPI_FREE(buffer.pointer);
        }

        /* Evaluate "_PSx" to see if we can do explicit sets */
        pathname[2] = 'S';
        if (acpi_has_method(device->handle, pathname))
                ps->flags.explicit_set = 1;

        /* State is valid if there are means to put the device into it. */
        if (!list_empty(&ps->resources) || ps->flags.explicit_set)
                ps->flags.valid = 1;

        ps->power = -1;         /* Unknown - driver assigned */
        ps->latency = -1;       /* Unknown - driver assigned */
}

static void acpi_bus_get_power_flags(struct acpi_device *device)
{
        unsigned long long dsc = ACPI_STATE_D0;
        u32 i;

        /* Presence of _PS0|_PR0 indicates 'power manageable' */
        if (!acpi_has_method(device->handle, "_PS0") &&
            !acpi_has_method(device->handle, "_PR0"))
                return;

        device->flags.power_manageable = 1;

        /*
         * Power Management Flags
         */
        if (acpi_has_method(device->handle, "_PSC"))
                device->power.flags.explicit_get = 1;

        if (acpi_has_method(device->handle, "_IRC"))
                device->power.flags.inrush_current = 1;

        if (acpi_has_method(device->handle, "_DSW"))
                device->power.flags.dsw_present = 1;

        acpi_evaluate_integer(device->handle, "_DSC", NULL, &dsc);
        device->power.state_for_enumeration = dsc;

        /*
         * Enumerate supported power management states
         */
        for (i = ACPI_STATE_D0; i <= ACPI_STATE_D3_HOT; i++)
                acpi_bus_init_power_state(device, i);

        INIT_LIST_HEAD(&device->power.states[ACPI_STATE_D3_COLD].resources);

        /* Set the defaults for D0 and D3hot (always supported). */
        device->power.states[ACPI_STATE_D0].flags.valid = 1;
        device->power.states[ACPI_STATE_D0].power = 100;
        device->power.states[ACPI_STATE_D3_HOT].flags.valid = 1;

        /*
         * Use power resources only if the D0 list of them is populated, because
         * some platforms may provide _PR3 only to indicate D3cold support and
         * in those cases the power resources list returned by it may be bogus.
         */
        if (!list_empty(&device->power.states[ACPI_STATE_D0].resources)) {
                device->power.flags.power_resources = 1;
                /*
                 * D3cold is supported if the D3hot list of power resources is
                 * not empty.
                 */
                if (!list_empty(&device->power.states[ACPI_STATE_D3_HOT].resources))
                        device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
        }

        if (acpi_bus_init_power(device))
                device->flags.power_manageable = 0;
}

static void acpi_bus_get_flags(struct acpi_device *device)
{
        /* Presence of _STA indicates 'dynamic_status' */
        if (acpi_has_method(device->handle, "_STA"))
                device->flags.dynamic_status = 1;

        /* Presence of _RMV indicates 'removable' */
        if (acpi_has_method(device->handle, "_RMV"))
                device->flags.removable = 1;

        /* Presence of _EJD|_EJ0 indicates 'ejectable' */
        if (acpi_has_method(device->handle, "_EJD") ||
            acpi_has_method(device->handle, "_EJ0"))
                device->flags.ejectable = 1;
}

static void acpi_device_get_busid(struct acpi_device *device)
{
        char bus_id[5] = { '?', 0 };
        struct acpi_buffer buffer = { sizeof(bus_id), bus_id };
        int i = 0;

        /*
         * Bus ID
         * ------
         * The device's Bus ID is simply the object name.
         * TBD: Shouldn't this value be unique (within the ACPI namespace)?
         */
        if (!acpi_dev_parent(device)) {
                strscpy(device->pnp.bus_id, "ACPI");
                return;
        }

        switch (device->device_type) {
        case ACPI_BUS_TYPE_POWER_BUTTON:
                strscpy(device->pnp.bus_id, "PWRF");
                break;
        case ACPI_BUS_TYPE_SLEEP_BUTTON:
                strscpy(device->pnp.bus_id, "SLPF");
                break;
        case ACPI_BUS_TYPE_ECDT_EC:
                strscpy(device->pnp.bus_id, "ECDT");
                break;
        default:
                acpi_get_name(device->handle, ACPI_SINGLE_NAME, &buffer);
                /* Clean up trailing underscores (if any) */
                for (i = 3; i > 1; i--) {
                        if (bus_id[i] == '_')
                                bus_id[i] = '\0';
                        else
                                break;
                }
                strscpy(device->pnp.bus_id, bus_id);
                break;
        }
}

/*
 * acpi_ata_match - see if an acpi object is an ATA device
 *
 * If an acpi object has one of the ACPI ATA methods defined,
 * then we can safely call it an ATA device.
 */
bool acpi_ata_match(acpi_handle handle)
{
        return acpi_has_method(handle, "_GTF") ||
               acpi_has_method(handle, "_GTM") ||
               acpi_has_method(handle, "_STM") ||
               acpi_has_method(handle, "_SDD");
}

/*
 * acpi_bay_match - see if an acpi object is an ejectable driver bay
 *
 * If an acpi object is ejectable and has one of the ACPI ATA methods defined,
 * then we can safely call it an ejectable drive bay
 */
bool acpi_bay_match(acpi_handle handle)
{
        acpi_handle phandle;

        if (!acpi_has_method(handle, "_EJ0"))
                return false;
        if (acpi_ata_match(handle))
                return true;
        if (ACPI_FAILURE(acpi_get_parent(handle, &phandle)))
                return false;

        return acpi_ata_match(phandle);
}

bool acpi_device_is_battery(struct acpi_device *adev)
{
        struct acpi_hardware_id *hwid;

        list_for_each_entry(hwid, &adev->pnp.ids, list)
                if (!strcmp("PNP0C0A", hwid->id))
                        return true;

        return false;
}

static bool is_ejectable_bay(struct acpi_device *adev)
{
        acpi_handle handle = adev->handle;

        if (acpi_has_method(handle, "_EJ0") && acpi_device_is_battery(adev))
                return true;

        return acpi_bay_match(handle);
}

/*
 * acpi_dock_match - see if an acpi object has a _DCK method
 */
bool acpi_dock_match(acpi_handle handle)
{
        return acpi_has_method(handle, "_DCK");
}

static acpi_status
acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
                          void **return_value)
{
        long *cap = context;

        if (acpi_has_method(handle, "_BCM") &&
            acpi_has_method(handle, "_BCL")) {
                acpi_handle_debug(handle, "Found generic backlight support\n");
                *cap |= ACPI_VIDEO_BACKLIGHT;
                /* We have backlight support, no need to scan further */
                return AE_CTRL_TERMINATE;
        }
        return 0;
}

/* Returns true if the ACPI object is a video device which can be
 * handled by video.ko.
 * The device will get a Linux specific CID added in scan.c to
 * identify the device as an ACPI graphics device
 * Be aware that the graphics device may not be physically present
 * Use acpi_video_get_capabilities() to detect general ACPI video
 * capabilities of present cards
 */
long acpi_is_video_device(acpi_handle handle)
{
        long video_caps = 0;

        /* Is this device able to support video switching ? */
        if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
                video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;

        /* Is this device able to retrieve a video ROM ? */
        if (acpi_has_method(handle, "_ROM"))
                video_caps |= ACPI_VIDEO_ROM_AVAILABLE;

        /* Is this device able to configure which video head to be POSTed ? */
        if (acpi_has_method(handle, "_VPO") &&
            acpi_has_method(handle, "_GPD") &&
            acpi_has_method(handle, "_SPD"))
                video_caps |= ACPI_VIDEO_DEVICE_POSTING;

        /* Only check for backlight functionality if one of the above hit. */
        if (video_caps)
                acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
                                    ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
                                    &video_caps, NULL);

        return video_caps;
}
EXPORT_SYMBOL(acpi_is_video_device);

const char *acpi_device_hid(struct acpi_device *device)
{
        struct acpi_hardware_id *hid;

        hid = list_first_entry_or_null(&device->pnp.ids, struct acpi_hardware_id, list);
        if (!hid)
                return dummy_hid;

        return hid->id;
}
EXPORT_SYMBOL(acpi_device_hid);

static void acpi_add_id(struct acpi_device_pnp *pnp, const char *dev_id)
{
        struct acpi_hardware_id *id;

        id = kmalloc(sizeof(*id), GFP_KERNEL);
        if (!id)
                return;

        id->id = kstrdup_const(dev_id, GFP_KERNEL);
        if (!id->id) {
                kfree(id);
                return;
        }

        list_add_tail(&id->list, &pnp->ids);
        pnp->type.hardware_id = 1;
}

/*
 * Old IBM workstations have a DSDT bug wherein the SMBus object
 * lacks the SMBUS01 HID and the methods do not have the necessary "_"
 * prefix.  Work around this.
 */
static bool acpi_ibm_smbus_match(acpi_handle handle)
{
        char node_name[ACPI_PATH_SEGMENT_LENGTH];
        struct acpi_buffer path = { sizeof(node_name), node_name };

        if (!dmi_name_in_vendors("IBM"))
                return false;

        /* Look for SMBS object */
        if (ACPI_FAILURE(acpi_get_name(handle, ACPI_SINGLE_NAME, &path)) ||
            strcmp("SMBS", path.pointer))
                return false;

        /* Does it have the necessary (but misnamed) methods? */
        if (acpi_has_method(handle, "SBI") &&
            acpi_has_method(handle, "SBR") &&
            acpi_has_method(handle, "SBW"))
                return true;

        return false;
}

static bool acpi_object_is_system_bus(acpi_handle handle)
{
        acpi_handle tmp;

        if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_SB", &tmp)) &&
            tmp == handle)
                return true;
        if (ACPI_SUCCESS(acpi_get_handle(NULL, "\\_TZ", &tmp)) &&
            tmp == handle)
                return true;

        return false;
}

static void acpi_set_pnp_ids(acpi_handle handle, struct acpi_device_pnp *pnp,
                             int device_type)
{
        struct acpi_device_info *info = NULL;
        struct acpi_pnp_device_id_list *cid_list;
        int i;

        switch (device_type) {
        case ACPI_BUS_TYPE_DEVICE:
                if (handle == ACPI_ROOT_OBJECT) {
                        acpi_add_id(pnp, ACPI_SYSTEM_HID);
                        break;
                }

                acpi_get_object_info(handle, &info);
                if (!info) {
                        pr_err("%s: Error reading device info\n", __func__);
                        return;
                }

                if (info->valid & ACPI_VALID_HID) {
                        acpi_add_id(pnp, info->hardware_id.string);
                        pnp->type.platform_id = 1;
                }
                if (info->valid & ACPI_VALID_CID) {
                        cid_list = &info->compatible_id_list;
                        for (i = 0; i < cid_list->count; i++)
                                acpi_add_id(pnp, cid_list->ids[i].string);
                }
                if (info->valid & ACPI_VALID_ADR) {
                        pnp->bus_address = info->address;
                        pnp->type.bus_address = 1;
                }
                if (info->valid & ACPI_VALID_UID)
                        pnp->unique_id = kstrdup(info->unique_id.string,
                                                        GFP_KERNEL);
                if (info->valid & ACPI_VALID_CLS)
                        acpi_add_id(pnp, info->class_code.string);

                kfree(info);

                /*
                 * Some devices don't reliably have _HIDs & _CIDs, so add
                 * synthetic HIDs to make sure drivers can find them.
                 */
                if (acpi_is_video_device(handle)) {
                        acpi_add_id(pnp, ACPI_VIDEO_HID);
                        pnp->type.backlight = 1;
                        break;
                }
                if (acpi_bay_match(handle))
                        acpi_add_id(pnp, ACPI_BAY_HID);
                else if (acpi_dock_match(handle))
                        acpi_add_id(pnp, ACPI_DOCK_HID);
                else if (acpi_ibm_smbus_match(handle))
                        acpi_add_id(pnp, ACPI_SMBUS_IBM_HID);
                else if (list_empty(&pnp->ids) &&
                         acpi_object_is_system_bus(handle)) {
                        /* \_SB, \_TZ, LNXSYBUS */
                        acpi_add_id(pnp, ACPI_BUS_HID);
                        strscpy(pnp->device_name, ACPI_BUS_DEVICE_NAME);
                        strscpy(pnp->device_class, ACPI_BUS_CLASS);
                }

                break;
        case ACPI_BUS_TYPE_POWER:
                acpi_add_id(pnp, ACPI_POWER_HID);
                break;
        case ACPI_BUS_TYPE_PROCESSOR:
                acpi_add_id(pnp, ACPI_PROCESSOR_OBJECT_HID);
                break;
        case ACPI_BUS_TYPE_THERMAL:
                acpi_add_id(pnp, ACPI_THERMAL_HID);
                break;
        case ACPI_BUS_TYPE_POWER_BUTTON:
                acpi_add_id(pnp, ACPI_BUTTON_HID_POWERF);
                break;
        case ACPI_BUS_TYPE_SLEEP_BUTTON:
                acpi_add_id(pnp, ACPI_BUTTON_HID_SLEEPF);
                break;
        case ACPI_BUS_TYPE_ECDT_EC:
                acpi_add_id(pnp, ACPI_ECDT_HID);
                break;
        }
}

void acpi_free_pnp_ids(struct acpi_device_pnp *pnp)
{
        struct acpi_hardware_id *id, *tmp;

        list_for_each_entry_safe(id, tmp, &pnp->ids, list) {
                kfree_const(id->id);
                kfree(id);
        }
        kfree(pnp->unique_id);
}

/**
 * acpi_dma_supported - Check DMA support for the specified device.
 * @adev: The pointer to acpi device
 *
 * Return false if DMA is not supported. Otherwise, return true
 */
bool acpi_dma_supported(const struct acpi_device *adev)
{
        if (!adev)
                return false;

        if (adev->flags.cca_seen)
                return true;

        /*
        * Per ACPI 6.0 sec 6.2.17, assume devices can do cache-coherent
        * DMA on "Intel platforms".  Presumably that includes all x86 and
        * ia64, and other arches will set CONFIG_ACPI_CCA_REQUIRED=y.
        */
        if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
                return true;

        return false;
}

/**
 * acpi_get_dma_attr - Check the supported DMA attr for the specified device.
 * @adev: The pointer to acpi device
 *
 * Return enum dev_dma_attr.
 */
enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
{
        if (!acpi_dma_supported(adev))
                return DEV_DMA_NOT_SUPPORTED;

        if (adev->flags.coherent_dma)
                return DEV_DMA_COHERENT;
        else
                return DEV_DMA_NON_COHERENT;
}

/**
 * acpi_dma_get_range() - Get device DMA parameters.
 *
 * @dev: device to configure
 * @map: pointer to DMA ranges result
 *
 * Evaluate DMA regions and return pointer to DMA regions on
 * parsing success; it does not update the passed in values on failure.
 *
 * Return 0 on success, < 0 on failure.
 */
int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
{
        struct acpi_device *adev;
        LIST_HEAD(list);
        struct resource_entry *rentry;
        int ret;
        struct device *dma_dev = dev;
        struct bus_dma_region *r;

        /*
         * Walk the device tree chasing an ACPI companion with a _DMA
         * object while we go. Stop if we find a device with an ACPI
         * companion containing a _DMA method.
         */
        do {
                adev = ACPI_COMPANION(dma_dev);
                if (adev && acpi_has_method(adev->handle, METHOD_NAME__DMA))
                        break;

                dma_dev = dma_dev->parent;
        } while (dma_dev);

        if (!dma_dev)
                return -ENODEV;

        if (!acpi_has_method(adev->handle, METHOD_NAME__CRS)) {
                acpi_handle_warn(adev->handle, "_DMA is valid only if _CRS is present\n");
                return -EINVAL;
        }

        ret = acpi_dev_get_dma_resources(adev, &list);
        if (ret > 0) {
                r = kcalloc(ret + 1, sizeof(*r), GFP_KERNEL);
                if (!r) {
                        ret = -ENOMEM;
                        goto out;
                }

                *map = r;

                list_for_each_entry(rentry, &list, node) {
                        if (rentry->res->start >= rentry->res->end) {
                                kfree(*map);
                                *map = NULL;
                                ret = -EINVAL;
                                dev_dbg(dma_dev, "Invalid DMA regions configuration\n");
                                goto out;
                        }

                        r->cpu_start = rentry->res->start;
                        r->dma_start = rentry->res->start - rentry->offset;
                        r->size = resource_size(rentry->res);
                        r++;
                }
        }
 out:
        acpi_dev_free_resource_list(&list);

        return ret >= 0 ? 0 : ret;
}

#ifdef CONFIG_IOMMU_API
int acpi_iommu_fwspec_init(struct device *dev, u32 id,
                           struct fwnode_handle *fwnode)
{
        int ret;

        ret = iommu_fwspec_init(dev, fwnode);
        if (ret)
                return ret;

        return iommu_fwspec_add_ids(dev, &id, 1);
}

static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
{
        int err;

        /* Serialise to make dev->iommu stable under our potential fwspec */
        mutex_lock(&iommu_probe_device_lock);
        /* If we already translated the fwspec there is nothing left to do */
        if (dev_iommu_fwspec_get(dev)) {
                mutex_unlock(&iommu_probe_device_lock);
                return 0;
        }

        err = iort_iommu_configure_id(dev, id_in);
        if (err && err != -EPROBE_DEFER)
                err = viot_iommu_configure(dev);
        mutex_unlock(&iommu_probe_device_lock);

        /*
         * If we have reason to believe the IOMMU driver missed the initial
         * iommu_probe_device() call for dev, replay it to get things in order.
         */
        if (!err && dev->bus)
                err = iommu_probe_device(dev);

        return err;
}

#else /* !CONFIG_IOMMU_API */

int acpi_iommu_fwspec_init(struct device *dev, u32 id,
                           struct fwnode_handle *fwnode)
{
        return -ENODEV;
}

static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
{
        return -ENODEV;
}

#endif /* !CONFIG_IOMMU_API */

/**
 * acpi_dma_configure_id - Set-up DMA configuration for the device.
 * @dev: The pointer to the device
 * @attr: device dma attributes
 * @input_id: input device id const value pointer
 */
int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
                          const u32 *input_id)
{
        int ret;

        if (attr == DEV_DMA_NOT_SUPPORTED) {
                set_dma_ops(dev, &dma_dummy_ops);
                return 0;
        }

        acpi_arch_dma_setup(dev);

        /* Ignore all other errors apart from EPROBE_DEFER */
        ret = acpi_iommu_configure_id(dev, input_id);
        if (ret == -EPROBE_DEFER)
                return -EPROBE_DEFER;
        if (ret)
                dev_dbg(dev, "Adding to IOMMU failed: %d\n", ret);

        arch_setup_dma_ops(dev, attr == DEV_DMA_COHERENT);

        return 0;
}
EXPORT_SYMBOL_GPL(acpi_dma_configure_id);

static void acpi_init_coherency(struct acpi_device *adev)
{
        unsigned long long cca = 0;
        acpi_status status;
        struct acpi_device *parent = acpi_dev_parent(adev);

        if (parent && parent->flags.cca_seen) {
                /*
                 * From ACPI spec, OSPM will ignore _CCA if an ancestor
                 * already saw one.
                 */
                adev->flags.cca_seen = 1;
                cca = parent->flags.coherent_dma;
        } else {
                status = acpi_evaluate_integer(adev->handle, "_CCA",
                                               NULL, &cca);
                if (ACPI_SUCCESS(status))
                        adev->flags.cca_seen = 1;
                else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED))
                        /*
                         * If architecture does not specify that _CCA is
                         * required for DMA-able devices (e.g. x86),
                         * we default to _CCA=1.
                         */
                        cca = 1;
                else
                        acpi_handle_debug(adev->handle,
                                          "ACPI device is missing _CCA.\n");
        }

        adev->flags.coherent_dma = cca;
}

static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data)
{
        bool *is_serial_bus_slave_p = data;

        if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
                return 1;

        *is_serial_bus_slave_p = true;

         /* no need to do more checking */
        return -1;
}

static bool acpi_is_indirect_io_slave(struct acpi_device *device)
{
        struct acpi_device *parent = acpi_dev_parent(device);
        static const struct acpi_device_id indirect_io_hosts[] = {
                {"HISI0191", 0},
                {}
        };

        return parent && !acpi_match_device_ids(parent, indirect_io_hosts);
}

static bool acpi_device_enumeration_by_parent(struct acpi_device *device)
{
        struct list_head resource_list;
        bool is_serial_bus_slave = false;
        static const struct acpi_device_id ignore_serial_bus_ids[] = {
        /*
         * These devices have multiple SerialBus resources and a client
         * device must be instantiated for each of them, each with
         * its own device id.
         * Normally we only instantiate one client device for the first
         * resource, using the ACPI HID as id. These special cases are handled
         * by the drivers/platform/x86/serial-multi-instantiate.c driver, which
         * knows which client device id to use for each resource.
         */
                {"BSG1160", },
                {"BSG2150", },
                {"CSC3551", },
                {"CSC3554", },
                {"CSC3556", },
                {"CSC3557", },
                {"INT33FE", },
                {"INT3515", },
                /* Non-conforming _HID for Cirrus Logic already released */
                {"CLSA0100", },
                {"CLSA0101", },
        /*
         * Some ACPI devs contain SerialBus resources even though they are not
         * attached to a serial bus at all.
         */
                {ACPI_VIDEO_HID, },
                {"MSHW0028", },
        /*
         * HIDs of device with an UartSerialBusV2 resource for which userspace
         * expects a regular tty cdev to be created (instead of the in kernel
         * serdev) and which have a kernel driver which expects a platform_dev
         * such as the rfkill-gpio driver.
         */
                {"BCM4752", },
                {"LNV4752", },
                {}
        };

        if (acpi_is_indirect_io_slave(device))
                return true;

        /* Macs use device properties in lieu of _CRS resources */
        if (x86_apple_machine &&
            (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
             fwnode_property_present(&device->fwnode, "i2cAddress") ||
             fwnode_property_present(&device->fwnode, "baud")))
                return true;

        if (!acpi_match_device_ids(device, ignore_serial_bus_ids))
                return false;

        INIT_LIST_HEAD(&resource_list);
        acpi_dev_get_resources(device, &resource_list,
                               acpi_check_serial_bus_slave,
                               &is_serial_bus_slave);
        acpi_dev_free_resource_list(&resource_list);

        return is_serial_bus_slave;
}

void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
                             int type, void (*release)(struct device *))
{
        struct acpi_device *parent = acpi_find_parent_acpi_dev(handle);

        INIT_LIST_HEAD(&device->pnp.ids);
        device->device_type = type;
        device->handle = handle;
        device->dev.parent = parent ? &parent->dev : NULL;
        device->dev.release = release;
        device->dev.bus = &acpi_bus_type;
        device->dev.groups = acpi_groups;
        fwnode_init(&device->fwnode, &acpi_device_fwnode_ops);
        acpi_set_device_status(device, ACPI_STA_DEFAULT);
        acpi_device_get_busid(device);
        acpi_set_pnp_ids(handle, &device->pnp, type);
        acpi_init_properties(device);
        acpi_bus_get_flags(device);
        device->flags.match_driver = false;
        device->flags.initialized = true;
        device->flags.enumeration_by_parent =
                acpi_device_enumeration_by_parent(device);
        acpi_device_clear_enumerated(device);
        device_initialize(&device->dev);
        dev_set_uevent_suppress(&device->dev, true);
        acpi_init_coherency(device);
}

static void acpi_scan_dep_init(struct acpi_device *adev)
{
        struct acpi_dep_data *dep;

        list_for_each_entry(dep, &acpi_dep_list, node) {
                if (dep->consumer == adev->handle) {
                        if (dep->honor_dep)
                                adev->flags.honor_deps = 1;

                        if (!dep->met)
                                adev->dep_unmet++;
                }
        }
}

void acpi_device_add_finalize(struct acpi_device *device)
{
        dev_set_uevent_suppress(&device->dev, false);
        kobject_uevent(&device->dev.kobj, KOBJ_ADD);
}

static void acpi_scan_init_status(struct acpi_device *adev)
{
        if (acpi_bus_get_status(adev))
                acpi_set_device_status(adev, 0);
}

static int acpi_add_single_object(struct acpi_device **child,
                                  acpi_handle handle, int type, bool dep_init)
{
        struct acpi_device *device;
        bool release_dep_lock = false;
        int result;

        device = kzalloc(sizeof(struct acpi_device), GFP_KERNEL);
        if (!device)
                return -ENOMEM;

        acpi_init_device_object(device, handle, type, acpi_device_release);
        /*
         * Getting the status is delayed till here so that we can call
         * acpi_bus_get_status() and use its quirk handling.  Note that
         * this must be done before the get power-/wakeup_dev-flags calls.
         */
        if (type == ACPI_BUS_TYPE_DEVICE || type == ACPI_BUS_TYPE_PROCESSOR) {
                if (dep_init) {
                        mutex_lock(&acpi_dep_list_lock);
                        /*
                         * Hold the lock until the acpi_tie_acpi_dev() call
                         * below to prevent concurrent acpi_scan_clear_dep()
                         * from deleting a dependency list entry without
                         * updating dep_unmet for the device.
                         */
                        release_dep_lock = true;
                        acpi_scan_dep_init(device);
                }
                acpi_scan_init_status(device);
        }

        acpi_bus_get_power_flags(device);
        acpi_bus_get_wakeup_device_flags(device);

        result = acpi_tie_acpi_dev(device);

        if (release_dep_lock)
                mutex_unlock(&acpi_dep_list_lock);

        if (!result)
                result = acpi_device_add(device);

        if (result) {
                acpi_device_release(&device->dev);
                return result;
        }

        acpi_power_add_remove_device(device, true);
        acpi_device_add_finalize(device);

        acpi_handle_debug(handle, "Added as %s, parent %s\n",
                          dev_name(&device->dev), device->dev.parent ?
                                dev_name(device->dev.parent) : "(null)");

        *child = device;
        return 0;
}

static acpi_status acpi_get_resource_memory(struct acpi_resource *ares,
                                            void *context)
{
        struct resource *res = context;

        if (acpi_dev_resource_memory(ares, res))
                return AE_CTRL_TERMINATE;

        return AE_OK;
}

static bool acpi_device_should_be_hidden(acpi_handle handle)
{
        acpi_status status;
        struct resource res;

        /* Check if it should ignore the UART device */
        if (!(spcr_uart_addr && acpi_has_method(handle, METHOD_NAME__CRS)))
                return false;

        /*
         * The UART device described in SPCR table is assumed to have only one
         * memory resource present. So we only look for the first one here.
         */
        status = acpi_walk_resources(handle, METHOD_NAME__CRS,
                                     acpi_get_resource_memory, &res);
        if (ACPI_FAILURE(status) || res.start != spcr_uart_addr)
                return false;

        acpi_handle_info(handle, "The UART device @%pa in SPCR table will be hidden\n",
                         &res.start);

        return true;
}

bool acpi_device_is_present(const struct acpi_device *adev)
{
        return adev->status.present || adev->status.functional;
}

bool acpi_device_is_enabled(const struct acpi_device *adev)
{
        return adev->status.enabled;
}

static bool acpi_scan_handler_matching(struct acpi_scan_handler *handler,
                                       const char *idstr,
                                       const struct acpi_device_id **matchid)
{
        const struct acpi_device_id *devid;

        if (handler->match)
                return handler->match(idstr, matchid);

        for (devid = handler->ids; devid->id[0]; devid++)
                if (!strcmp((char *)devid->id, idstr)) {
                        if (matchid)
                                *matchid = devid;

                        return true;
                }

        return false;
}

static struct acpi_scan_handler *acpi_scan_match_handler(const char *idstr,
                                        const struct acpi_device_id **matchid)
{
        struct acpi_scan_handler *handler;

        list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
                if (acpi_scan_handler_matching(handler, idstr, matchid))
                        return handler;

        return NULL;
}

void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val)
{
        if (!!hotplug->enabled == !!val)
                return;

        mutex_lock(&acpi_scan_lock);

        hotplug->enabled = val;

        mutex_unlock(&acpi_scan_lock);
}

int acpi_scan_add_dep(acpi_handle handle, struct acpi_handle_list *dep_devices)
{
        u32 count;
        int i;

        for (count = 0, i = 0; i < dep_devices->count; i++) {
                struct acpi_device_info *info;
                struct acpi_dep_data *dep;
                bool skip, honor_dep;
                acpi_status status;

                status = acpi_get_object_info(dep_devices->handles[i], &info);
                if (ACPI_FAILURE(status)) {
                        acpi_handle_debug(handle, "Error reading _DEP device info\n");
                        continue;
                }

                skip = acpi_info_matches_ids(info, acpi_ignore_dep_ids);
                honor_dep = acpi_info_matches_ids(info, acpi_honor_dep_ids);
                kfree(info);

                if (skip)
                        continue;

                dep = kzalloc(sizeof(*dep), GFP_KERNEL);
                if (!dep)
                        continue;

                count++;

                dep->supplier = dep_devices->handles[i];
                dep->consumer = handle;
                dep->honor_dep = honor_dep;

                mutex_lock(&acpi_dep_list_lock);
                list_add_tail(&dep->node, &acpi_dep_list);
                mutex_unlock(&acpi_dep_list_lock);
        }

        acpi_handle_list_free(dep_devices);
        return count;
}

static void acpi_scan_init_hotplug(struct acpi_device *adev)
{
        struct acpi_hardware_id *hwid;

        if (acpi_dock_match(adev->handle) || is_ejectable_bay(adev)) {
                acpi_dock_add(adev);
                return;
        }
        list_for_each_entry(hwid, &adev->pnp.ids, list) {
                struct acpi_scan_handler *handler;

                handler = acpi_scan_match_handler(hwid->id, NULL);
                if (handler) {
                        adev->flags.hotplug_notify = true;
                        break;
                }
        }
}

u32 __weak arch_acpi_add_auto_dep(acpi_handle handle) { return 0; }

static u32 acpi_scan_check_dep(acpi_handle handle)
{
        struct acpi_handle_list dep_devices;
        u32 count = 0;

        /*
         * Some architectures like RISC-V need to add dependencies for
         * all devices which use GSI to the interrupt controller so that
         * interrupt controller is probed before any of those devices.
         * Instead of mandating _DEP on all the devices, detect the
         * dependency and add automatically.
         */
        count += arch_acpi_add_auto_dep(handle);

        /*
         * Check for _HID here to avoid deferring the enumeration of:
         * 1. PCI devices.
         * 2. ACPI nodes describing USB ports.
         * Still, checking for _HID catches more then just these cases ...
         */
        if (!acpi_has_method(handle, "_DEP") || !acpi_has_method(handle, "_HID"))
                return count;

        if (!acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices)) {
                acpi_handle_debug(handle, "Failed to evaluate _DEP.\n");
                return count;
        }

        count += acpi_scan_add_dep(handle, &dep_devices);
        return count;
}

static acpi_status acpi_scan_check_crs_csi2_cb(acpi_handle handle, u32 a, void *b, void **c)
{
        acpi_mipi_check_crs_csi2(handle);
        return AE_OK;
}

static acpi_status acpi_bus_check_add(acpi_handle handle, bool first_pass,
                                      struct acpi_device **adev_p)
{
        struct acpi_device *device = acpi_fetch_acpi_dev(handle);
        acpi_object_type acpi_type;
        int type;

        if (device)
                goto out;

        if (ACPI_FAILURE(acpi_get_type(handle, &acpi_type)))
                return AE_OK;

        switch (acpi_type) {
        case ACPI_TYPE_DEVICE:
                if (acpi_device_should_be_hidden(handle))
                        return AE_OK;

                if (first_pass) {
                        acpi_mipi_check_crs_csi2(handle);

                        /* Bail out if there are dependencies. */
                        if (acpi_scan_check_dep(handle) > 0) {
                                /*
                                 * The entire CSI-2 connection graph needs to be
                                 * extracted before any drivers or scan handlers
                                 * are bound to struct device objects, so scan
                                 * _CRS CSI-2 resource descriptors for all
                                 * devices below the current handle.
                                 */
                                acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
                                                    ACPI_UINT32_MAX,
                                                    acpi_scan_check_crs_csi2_cb,
                                                    NULL, NULL, NULL);
                                return AE_CTRL_DEPTH;
                        }
                }

                fallthrough;
        case ACPI_TYPE_ANY:     /* for ACPI_ROOT_OBJECT */
                type = ACPI_BUS_TYPE_DEVICE;
                break;

        case ACPI_TYPE_PROCESSOR:
                type = ACPI_BUS_TYPE_PROCESSOR;
                break;

        case ACPI_TYPE_THERMAL:
                type = ACPI_BUS_TYPE_THERMAL;
                break;

        case ACPI_TYPE_POWER:
                acpi_add_power_resource(handle);
                fallthrough;
        default:
                return AE_OK;
        }

        /*
         * If first_pass is true at this point, the device has no dependencies,
         * or the creation of the device object would have been postponed above.
         */
        acpi_add_single_object(&device, handle, type, !first_pass);
        if (!device)
                return AE_CTRL_DEPTH;

        acpi_scan_init_hotplug(device);

out:
        if (!*adev_p)
                *adev_p = device;

        return AE_OK;
}

static acpi_status acpi_bus_check_add_1(acpi_handle handle, u32 lvl_not_used,
                                        void *not_used, void **ret_p)
{
        return acpi_bus_check_add(handle, true, (struct acpi_device **)ret_p);
}

static acpi_status acpi_bus_check_add_2(acpi_handle handle, u32 lvl_not_used,
                                        void *not_used, void **ret_p)
{
        return acpi_bus_check_add(handle, false, (struct acpi_device **)ret_p);
}

static void acpi_default_enumeration(struct acpi_device *device)
{
        /*
         * Do not enumerate devices with enumeration_by_parent flag set as
         * they will be enumerated by their respective parents.
         */
        if (!device->flags.enumeration_by_parent) {
                acpi_create_platform_device(device, NULL);
                acpi_device_set_enumerated(device);
        } else {
                blocking_notifier_call_chain(&acpi_reconfig_chain,
                                             ACPI_RECONFIG_DEVICE_ADD, device);
        }
}

static const struct acpi_device_id generic_device_ids[] = {
        {ACPI_DT_NAMESPACE_HID, },
        {"", },
};

static int acpi_generic_device_attach(struct acpi_device *adev,
                                      const struct acpi_device_id *not_used)
{
        /*
         * Since ACPI_DT_NAMESPACE_HID is the only ID handled here, the test
         * below can be unconditional.
         */
        if (adev->data.of_compatible)
                acpi_default_enumeration(adev);

        return 1;
}

static struct acpi_scan_handler generic_device_handler = {
        .ids = generic_device_ids,
        .attach = acpi_generic_device_attach,
};

static int acpi_scan_attach_handler(struct acpi_device *device)
{
        struct acpi_hardware_id *hwid;
        int ret = 0;

        list_for_each_entry(hwid, &device->pnp.ids, list) {
                const struct acpi_device_id *devid;
                struct acpi_scan_handler *handler;

                handler = acpi_scan_match_handler(hwid->id, &devid);
                if (handler) {
                        if (!handler->attach) {
                                device->pnp.type.platform_id = 0;
                                continue;
                        }
                        device->handler = handler;
                        ret = handler->attach(device, devid);
                        if (ret > 0)
                                break;

                        device->handler = NULL;
                        if (ret < 0)
                                break;
                }
        }

        return ret;
}

static int acpi_bus_attach(struct acpi_device *device, void *first_pass)
{
        bool skip = !first_pass && device->flags.visited;
        acpi_handle ejd;
        int ret;

        if (skip)
                goto ok;

        if (ACPI_SUCCESS(acpi_bus_get_ejd(device->handle, &ejd)))
                register_dock_dependent_device(device, ejd);

        acpi_bus_get_status(device);
        /* Skip devices that are not ready for enumeration (e.g. not present) */
        if (!acpi_dev_ready_for_enumeration(device)) {
                device->flags.initialized = false;
                acpi_device_clear_enumerated(device);
                device->flags.power_manageable = 0;
                return 0;
        }
        if (device->handler)
                goto ok;

        acpi_ec_register_opregions(device);

        if (!device->flags.initialized) {
                device->flags.power_manageable =
                        device->power.states[ACPI_STATE_D0].flags.valid;
                if (acpi_bus_init_power(device))
                        device->flags.power_manageable = 0;

                device->flags.initialized = true;
        } else if (device->flags.visited) {
                goto ok;
        }

        ret = acpi_scan_attach_handler(device);
        if (ret < 0)
                return 0;

        device->flags.match_driver = true;
        if (ret > 0 && !device->flags.enumeration_by_parent) {
                acpi_device_set_enumerated(device);
                goto ok;
        }

        ret = device_attach(&device->dev);
        if (ret < 0)
                return 0;

        if (device->pnp.type.platform_id || device->flags.enumeration_by_parent)
                acpi_default_enumeration(device);
        else
                acpi_device_set_enumerated(device);

ok:
        acpi_dev_for_each_child(device, acpi_bus_attach, first_pass);

        if (!skip && device->handler && device->handler->hotplug.notify_online)
                device->handler->hotplug.notify_online(device);

        return 0;
}

static int acpi_dev_get_next_consumer_dev_cb(struct acpi_dep_data *dep, void *data)
{
        struct acpi_device **adev_p = data;
        struct acpi_device *adev = *adev_p;

        /*
         * If we're passed a 'previous' consumer device then we need to skip
         * any consumers until we meet the previous one, and then NULL @data
         * so the next one can be returned.
         */
        if (adev) {
                if (dep->consumer == adev->handle)
                        *adev_p = NULL;

                return 0;
        }

        adev = acpi_get_acpi_dev(dep->consumer);
        if (adev) {
                *(struct acpi_device **)data = adev;
                return 1;
        }
        /* Continue parsing if the device object is not present. */
        return 0;
}

struct acpi_scan_clear_dep_work {
        struct work_struct work;
        struct acpi_device *adev;
};

static void acpi_scan_clear_dep_fn(struct work_struct *work)
{
        struct acpi_scan_clear_dep_work *cdw;

        cdw = container_of(work, struct acpi_scan_clear_dep_work, work);

        acpi_scan_lock_acquire();
        acpi_bus_attach(cdw->adev, (void *)true);
        acpi_scan_lock_release();

        acpi_dev_put(cdw->adev);
        kfree(cdw);
}

static bool acpi_scan_clear_dep_queue(struct acpi_device *adev)
{
        struct acpi_scan_clear_dep_work *cdw;

        if (adev->dep_unmet)
                return false;

        cdw = kmalloc(sizeof(*cdw), GFP_KERNEL);
        if (!cdw)
                return false;

        cdw->adev = adev;
        INIT_WORK(&cdw->work, acpi_scan_clear_dep_fn);
        /*
         * Since the work function may block on the lock until the entire
         * initial enumeration of devices is complete, put it into the unbound
         * workqueue.
         */
        queue_work(system_unbound_wq, &cdw->work);

        return true;
}

static void acpi_scan_delete_dep_data(struct acpi_dep_data *dep)
{
        list_del(&dep->node);
        kfree(dep);
}

static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
{
        struct acpi_device *adev = acpi_get_acpi_dev(dep->consumer);

        if (adev) {
                adev->dep_unmet--;
                if (!acpi_scan_clear_dep_queue(adev))
                        acpi_dev_put(adev);
        }

        if (dep->free_when_met)
                acpi_scan_delete_dep_data(dep);
        else
                dep->met = true;

        return 0;
}

/**
 * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
 * @handle:     The ACPI handle of the supplier device
 * @callback:   Pointer to the callback function to apply
 * @data:       Pointer to some data to pass to the callback
 *
 * The return value of the callback determines this function's behaviour. If 0
 * is returned we continue to iterate over acpi_dep_list. If a positive value
 * is returned then the loop is broken but this function returns 0. If a
 * negative value is returned by the callback then the loop is broken and that
 * value is returned as the final error.
 */
static int acpi_walk_dep_device_list(acpi_handle handle,
                                int (*callback)(struct acpi_dep_data *, void *),
                                void *data)
{
        struct acpi_dep_data *dep, *tmp;
        int ret = 0;

        mutex_lock(&acpi_dep_list_lock);
        list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
                if (dep->supplier == handle) {
                        ret = callback(dep, data);
                        if (ret)
                                break;
                }
        }
        mutex_unlock(&acpi_dep_list_lock);

        return ret > 0 ? 0 : ret;
}

/**
 * acpi_dev_clear_dependencies - Inform consumers that the device is now active
 * @supplier: Pointer to the supplier &struct acpi_device
 *
 * Clear dependencies on the given device.
 */
void acpi_dev_clear_dependencies(struct acpi_device *supplier)
{
        acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
}
EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);

/**
 * acpi_dev_ready_for_enumeration - Check if the ACPI device is ready for enumeration
 * @device: Pointer to the &struct acpi_device to check
 *
 * Check if the device is present and has no unmet dependencies.
 *
 * Return true if the device is ready for enumeratino. Otherwise, return false.
 */
bool acpi_dev_ready_for_enumeration(const struct acpi_device *device)
{
        if (device->flags.honor_deps && device->dep_unmet)
                return false;

        return acpi_device_is_present(device);
}
EXPORT_SYMBOL_GPL(acpi_dev_ready_for_enumeration);

/**
 * acpi_dev_get_next_consumer_dev - Return the next adev dependent on @supplier
 * @supplier: Pointer to the dependee device
 * @start: Pointer to the current dependent device
 *
 * Returns the next &struct acpi_device which declares itself dependent on
 * @supplier via the _DEP buffer, parsed from the acpi_dep_list.
 *
 * If the returned adev is not passed as @start to this function, the caller is
 * responsible for putting the reference to adev when it is no longer needed.
 */
struct acpi_device *acpi_dev_get_next_consumer_dev(struct acpi_device *supplier,
                                                   struct acpi_device *start)
{
        struct acpi_device *adev = start;

        acpi_walk_dep_device_list(supplier->handle,
                                  acpi_dev_get_next_consumer_dev_cb, &adev);

        acpi_dev_put(start);

        if (adev == start)
                return NULL;

        return adev;
}
EXPORT_SYMBOL_GPL(acpi_dev_get_next_consumer_dev);

static void acpi_scan_postponed_branch(acpi_handle handle)
{
        struct acpi_device *adev = NULL;

        if (ACPI_FAILURE(acpi_bus_check_add(handle, false, &adev)))
                return;

        acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                            acpi_bus_check_add_2, NULL, NULL, (void **)&adev);

        /*
         * Populate the ACPI _CRS CSI-2 software nodes for the ACPI devices that
         * have been added above.
         */
        acpi_mipi_init_crs_csi2_swnodes();

        acpi_bus_attach(adev, NULL);
}

static void acpi_scan_postponed(void)
{
        struct acpi_dep_data *dep, *tmp;

        mutex_lock(&acpi_dep_list_lock);

        list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
                acpi_handle handle = dep->consumer;

                /*
                 * In case there are multiple acpi_dep_list entries with the
                 * same consumer, skip the current entry if the consumer device
                 * object corresponding to it is present already.
                 */
                if (!acpi_fetch_acpi_dev(handle)) {
                        /*
                         * Even though the lock is released here, tmp is
                         * guaranteed to be valid, because none of the list
                         * entries following dep is marked as "free when met"
                         * and so they cannot be deleted.
                         */
                        mutex_unlock(&acpi_dep_list_lock);

                        acpi_scan_postponed_branch(handle);

                        mutex_lock(&acpi_dep_list_lock);
                }

                if (dep->met)
                        acpi_scan_delete_dep_data(dep);
                else
                        dep->free_when_met = true;
        }

        mutex_unlock(&acpi_dep_list_lock);
}

/**
 * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
 * @handle: Root of the namespace scope to scan.
 *
 * Scan a given ACPI tree (probably recently hot-plugged) and create and add
 * found devices.
 *
 * If no devices were found, -ENODEV is returned, but it does not mean that
 * there has been a real error.  There just have been no suitable ACPI objects
 * in the table trunk from which the kernel could create a device and add an
 * appropriate driver.
 *
 * Must be called under acpi_scan_lock.
 */
int acpi_bus_scan(acpi_handle handle)
{
        struct acpi_device *device = NULL;

        /* Pass 1: Avoid enumerating devices with missing dependencies. */

        if (ACPI_SUCCESS(acpi_bus_check_add(handle, true, &device)))
                acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX,
                                    acpi_bus_check_add_1, NULL, NULL,
                                    (void **)&device);

        if (!device)
                return -ENODEV;

        /*
         * Set up ACPI _CRS CSI-2 software nodes using information extracted
         * from the _CRS CSI-2 resource descriptors during the ACPI namespace
         * walk above and MIPI DisCo for Imaging device properties.
         */
        acpi_mipi_scan_crs_csi2();
        acpi_mipi_init_crs_csi2_swnodes();

        acpi_bus_attach(device, (void *)true);

        /* Pass 2: Enumerate all of the remaining devices. */

        acpi_scan_postponed();

        acpi_mipi_crs_csi2_cleanup();

        return 0;
}
EXPORT_SYMBOL(acpi_bus_scan);

/**
 * acpi_bus_trim - Detach scan handlers and drivers from ACPI device objects.
 * @adev: Root of the ACPI namespace scope to walk.
 *
 * Must be called under acpi_scan_lock.
 */
void acpi_bus_trim(struct acpi_device *adev)
{
        uintptr_t flags = 0;

        acpi_scan_check_and_detach(adev, (void *)flags);
}
EXPORT_SYMBOL_GPL(acpi_bus_trim);

int acpi_bus_register_early_device(int type)
{
        struct acpi_device *device = NULL;
        int result;

        result = acpi_add_single_object(&device, NULL, type, false);
        if (result)
                return result;

        device->flags.match_driver = true;
        return device_attach(&device->dev);
}
EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);

static void acpi_bus_scan_fixed(void)
{
        if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
                struct acpi_device *adev = NULL;

                acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
                                       false);
                if (adev) {
                        adev->flags.match_driver = true;
                        if (device_attach(&adev->dev) >= 0)
                                device_init_wakeup(&adev->dev, true);
                        else
                                dev_dbg(&adev->dev, "No driver\n");
                }
        }

        if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
                struct acpi_device *adev = NULL;

                acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
                                       false);
                if (adev) {
                        adev->flags.match_driver = true;
                        if (device_attach(&adev->dev) < 0)
                                dev_dbg(&adev->dev, "No driver\n");
                }
        }
}

static void __init acpi_get_spcr_uart_addr(void)
{
        acpi_status status;
        struct acpi_table_spcr *spcr_ptr;

        status = acpi_get_table(ACPI_SIG_SPCR, 0,
                                (struct acpi_table_header **)&spcr_ptr);
        if (ACPI_FAILURE(status)) {
                pr_warn("STAO table present, but SPCR is missing\n");
                return;
        }

        spcr_uart_addr = spcr_ptr->serial_port.address;
        acpi_put_table((struct acpi_table_header *)spcr_ptr);
}

static bool acpi_scan_initialized;

void __init acpi_scan_init(void)
{
        acpi_status status;
        struct acpi_table_stao *stao_ptr;

        acpi_pci_root_init();
        acpi_pci_link_init();
        acpi_processor_init();
        acpi_platform_init();
        acpi_lpss_init();
        acpi_apd_init();
        acpi_cmos_rtc_init();
        acpi_container_init();
        acpi_memory_hotplug_init();
        acpi_watchdog_init();
        acpi_pnp_init();
        acpi_int340x_thermal_init();
        acpi_init_lpit();

        acpi_scan_add_handler(&generic_device_handler);

        /*
         * If there is STAO table, check whether it needs to ignore the UART
         * device in SPCR table.
         */
        status = acpi_get_table(ACPI_SIG_STAO, 0,
                                (struct acpi_table_header **)&stao_ptr);
        if (ACPI_SUCCESS(status)) {
                if (stao_ptr->header.length > sizeof(struct acpi_table_stao))
                        pr_info("STAO Name List not yet supported.\n");

                if (stao_ptr->ignore_uart)
                        acpi_get_spcr_uart_addr();

                acpi_put_table((struct acpi_table_header *)stao_ptr);
        }

        acpi_gpe_apply_masked_gpes();
        acpi_update_all_gpes();

        /*
         * Although we call __add_memory() that is documented to require the
         * device_hotplug_lock, it is not necessary here because this is an
         * early code when userspace or any other code path cannot trigger
         * hotplug/hotunplug operations.
         */
        mutex_lock(&acpi_scan_lock);
        /*
         * Enumerate devices in the ACPI namespace.
         */
        if (acpi_bus_scan(ACPI_ROOT_OBJECT))
                goto unlock;

        acpi_root = acpi_fetch_acpi_dev(ACPI_ROOT_OBJECT);
        if (!acpi_root)
                goto unlock;

        /* Fixed feature devices do not exist on HW-reduced platform */
        if (!acpi_gbl_reduced_hardware)
                acpi_bus_scan_fixed();

        acpi_turn_off_unused_power_resources();

        acpi_scan_initialized = true;

unlock:
        mutex_unlock(&acpi_scan_lock);
}

static struct acpi_probe_entry *ape;
static int acpi_probe_count;
static DEFINE_MUTEX(acpi_probe_mutex);

static int __init acpi_match_madt(union acpi_subtable_headers *header,
                                  const unsigned long end)
{
        if (!ape->subtable_valid || ape->subtable_valid(&header->common, ape))
                if (!ape->probe_subtbl(header, end))
                        acpi_probe_count++;

        return 0;
}

void __weak arch_sort_irqchip_probe(struct acpi_probe_entry *ap_head, int nr) { }

int __init __acpi_probe_device_table(struct acpi_probe_entry *ap_head, int nr)
{
        int count = 0;

        if (acpi_disabled)
                return 0;

        mutex_lock(&acpi_probe_mutex);
        arch_sort_irqchip_probe(ap_head, nr);
        for (ape = ap_head; nr; ape++, nr--) {
                if (ACPI_COMPARE_NAMESEG(ACPI_SIG_MADT, ape->id)) {
                        acpi_probe_count = 0;
                        acpi_table_parse_madt(ape->type, acpi_match_madt, 0);
                        count += acpi_probe_count;
                } else {
                        int res;
                        res = acpi_table_parse(ape->id, ape->probe_table);
                        if (!res)
                                count++;
                }
        }
        mutex_unlock(&acpi_probe_mutex);

        return count;
}

static void acpi_table_events_fn(struct work_struct *work)
{
        acpi_scan_lock_acquire();
        acpi_bus_scan(ACPI_ROOT_OBJECT);
        acpi_scan_lock_release();

        kfree(work);
}

void acpi_scan_table_notify(void)
{
        struct work_struct *work;

        if (!acpi_scan_initialized)
                return;

        work = kmalloc(sizeof(*work), GFP_KERNEL);
        if (!work)
                return;

        INIT_WORK(work, acpi_table_events_fn);
        schedule_work(work);
}

int acpi_reconfig_notifier_register(struct notifier_block *nb)
{
        return blocking_notifier_chain_register(&acpi_reconfig_chain, nb);
}
EXPORT_SYMBOL(acpi_reconfig_notifier_register);

int acpi_reconfig_notifier_unregister(struct notifier_block *nb)
{
        return blocking_notifier_chain_unregister(&acpi_reconfig_chain, nb);
}
EXPORT_SYMBOL(acpi_reconfig_notifier_unregister);