// SPDX-License-Identifier: GPL-2.0
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>

#include "pci.h"

static void pci_free_resources(struct pci_dev *dev)
{
        struct resource *res;

        pci_dev_for_each_resource(dev, res) {
                if (res->parent)
                        release_resource(res);
        }
}

static void pci_stop_dev(struct pci_dev *dev)
{
        pci_pme_active(dev, false);

        if (!pci_dev_test_and_clear_added(dev))
                return;

        device_release_driver(&dev->dev);
        pci_proc_detach_device(dev);
        pci_remove_sysfs_dev_files(dev);
        of_pci_remove_node(dev);
}

static void pci_destroy_dev(struct pci_dev *dev)
{
        if (pci_dev_test_and_set_removed(dev))
                return;

        pci_doe_sysfs_teardown(dev);
        pci_npem_remove(dev);

        /*
         * While device is in D0 drop the device from TSM link operations
         * including unbind and disconnect (IDE + SPDM teardown).
         */
        pci_tsm_destroy(dev);

        device_del(&dev->dev);

        down_write(&pci_bus_sem);
        list_del(&dev->bus_list);
        up_write(&pci_bus_sem);

        pci_doe_destroy(dev);
        pci_ide_destroy(dev);
        pcie_aspm_exit_link_state(dev);
        pci_bridge_d3_update(dev);
        pci_free_resources(dev);
        put_device(&dev->dev);
}

void pci_remove_bus(struct pci_bus *bus)
{
        pci_proc_detach_bus(bus);

        down_write(&pci_bus_sem);
        list_del(&bus->node);
        pci_bus_release_busn_res(bus);
        up_write(&pci_bus_sem);
        pci_remove_legacy_files(bus);

        if (bus->ops->remove_bus)
                bus->ops->remove_bus(bus);

        pcibios_remove_bus(bus);
        device_unregister(&bus->dev);
}
EXPORT_SYMBOL(pci_remove_bus);

static void pci_stop_bus_device(struct pci_dev *dev)
{
        struct pci_bus *bus = dev->subordinate;
        struct pci_dev *child, *tmp;

        /*
         * Stopping an SR-IOV PF device removes all the associated VFs,
         * which will update the bus->devices list and confuse the
         * iterator.  Therefore, iterate in reverse so we remove the VFs
         * first, then the PF.
         */
        if (bus) {
                list_for_each_entry_safe_reverse(child, tmp,
                                                 &bus->devices, bus_list)
                        pci_stop_bus_device(child);
        }

        pci_stop_dev(dev);
}

static void pci_remove_bus_device(struct pci_dev *dev)
{
        struct pci_bus *bus = dev->subordinate;
        struct pci_dev *child, *tmp;

        if (bus) {
                list_for_each_entry_safe(child, tmp,
                                         &bus->devices, bus_list)
                        pci_remove_bus_device(child);

                pci_remove_bus(bus);
                dev->subordinate = NULL;
        }

        pci_destroy_dev(dev);
}

/**
 * pci_stop_and_remove_bus_device - remove a PCI device and any children
 * @dev: the device to remove
 *
 * Remove a PCI device from the device lists, informing the drivers
 * that the device has been removed.  We also remove any subordinate
 * buses and children in a depth-first manner.
 *
 * For each device we remove, delete the device structure from the
 * device lists, remove the /proc entry, and notify userspace
 * (/sbin/hotplug).
 */
void pci_stop_and_remove_bus_device(struct pci_dev *dev)
{
        lockdep_assert_held(&pci_rescan_remove_lock);
        pci_stop_bus_device(dev);
        pci_remove_bus_device(dev);
}
EXPORT_SYMBOL(pci_stop_and_remove_bus_device);

void pci_stop_and_remove_bus_device_locked(struct pci_dev *dev)
{
        pci_lock_rescan_remove();
        pci_stop_and_remove_bus_device(dev);
        pci_unlock_rescan_remove();
}
EXPORT_SYMBOL_GPL(pci_stop_and_remove_bus_device_locked);

void pci_stop_root_bus(struct pci_bus *bus)
{
        struct pci_dev *child, *tmp;
        struct pci_host_bridge *host_bridge;

        if (!pci_is_root_bus(bus))
                return;

        host_bridge = to_pci_host_bridge(bus->bridge);
        list_for_each_entry_safe_reverse(child, tmp,
                                         &bus->devices, bus_list)
                pci_stop_bus_device(child);

        of_pci_remove_host_bridge_node(host_bridge);

        /* stop the host bridge */
        device_release_driver(&host_bridge->dev);
}
EXPORT_SYMBOL_GPL(pci_stop_root_bus);

void pci_remove_root_bus(struct pci_bus *bus)
{
        struct pci_dev *child, *tmp;
        struct pci_host_bridge *host_bridge;

        if (!pci_is_root_bus(bus))
                return;

        host_bridge = to_pci_host_bridge(bus->bridge);
        list_for_each_entry_safe(child, tmp,
                                 &bus->devices, bus_list)
                pci_remove_bus_device(child);

#ifdef CONFIG_PCI_DOMAINS_GENERIC
        /* Release domain_nr if it was dynamically allocated */
        if (host_bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET)
                pci_bus_release_domain_nr(host_bridge->dev.parent, bus->domain_nr);
#endif

        pci_remove_bus(bus);
        host_bridge->bus = NULL;

        /* remove the host bridge */
        device_del(&host_bridge->dev);
}
EXPORT_SYMBOL_GPL(pci_remove_root_bus);