/*
 * QDev Hotplug handlers
 *
 * Copyright (c) Red Hat
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"
#include "hw/core/qdev.h"
#include "hw/core/boards.h"
#include "qapi/error.h"

HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev)
{
    MachineState *machine;
    MachineClass *mc;
    Object *m_obj = qdev_get_machine();

    if (object_dynamic_cast(m_obj, TYPE_MACHINE)) {
        machine = MACHINE(m_obj);
        mc = MACHINE_GET_CLASS(machine);
        if (mc->get_hotplug_handler) {
            return mc->get_hotplug_handler(machine, dev);
        }
    }

    return NULL;
}

static bool qdev_hotplug_unplug_allowed_common(DeviceState *dev, BusState *bus,
                                               Error **errp)
{
    DeviceClass *dc = DEVICE_GET_CLASS(dev);

    if (!dc->hotpluggable) {
        error_setg(errp, "Device '%s' does not support hotplugging",
                   object_get_typename(OBJECT(dev)));
        return false;
    }

    if (bus) {
        if (!qbus_is_hotpluggable(bus)) {
            error_setg(errp, "Bus '%s' does not support hotplugging",
                       bus->name);
            return false;
        }
    } else {
        if (!qdev_get_machine_hotplug_handler(dev)) {
            /*
             * No bus, no machine hotplug handler --> device is not hotpluggable
             */
            error_setg(errp,
                       "Device '%s' can not be hotplugged on this machine",
                       object_get_typename(OBJECT(dev)));
            return false;
        }
    }

    return true;
}

bool qdev_hotplug_allowed(DeviceState *dev, BusState *bus, Error **errp)
{
    MachineState *machine;
    MachineClass *mc;
    Object *m_obj = qdev_get_machine();

    if (!qdev_hotplug_unplug_allowed_common(dev, bus, errp)) {
        return false;
    }

    if (object_dynamic_cast(m_obj, TYPE_MACHINE)) {
        machine = MACHINE(m_obj);
        mc = MACHINE_GET_CLASS(machine);
        if (mc->hotplug_allowed) {
            return mc->hotplug_allowed(machine, dev, errp);
        }
    }

    return true;
}

bool qdev_hotunplug_allowed(DeviceState *dev, Error **errp)
{
    return !qdev_unplug_blocked(dev, errp) &&
           qdev_hotplug_unplug_allowed_common(dev, dev->parent_bus, errp);
}

HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev)
{
    if (dev->parent_bus) {
        return dev->parent_bus->hotplug_handler;
    }
    return NULL;
}

HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
{
    HotplugHandler *hotplug_ctrl = qdev_get_machine_hotplug_handler(dev);

    if (hotplug_ctrl == NULL && dev->parent_bus) {
        hotplug_ctrl = qdev_get_bus_hotplug_handler(dev);
    }
    return hotplug_ctrl;
}

/* can be used as ->unplug() callback for the simple cases */
void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,
                                  DeviceState *dev, Error **errp)
{
    qdev_unrealize(dev);
}