// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PCI Dynamic LPAR, PCI Hot Plug and PCI EEH recovery code
 * for RPA-compliant PPC64 platform.
 * Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
 * Copyright (C) 2005 International Business Machines
 *
 * Updates, 2005, John Rose <johnrose@austin.ibm.com>
 * Updates, 2005, Linas Vepstas <linas@austin.ibm.com>
 */

#include <linux/pci.h>
#include <linux/export.h>
#include <linux/node.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/firmware.h>
#include <asm/eeh.h>

#include "pseries.h"

struct pci_controller *init_phb_dynamic(struct device_node *dn)
{
        struct pci_controller *phb;
        int nid;

        pr_debug("PCI: Initializing new hotplug PHB %pOF\n", dn);

        nid = of_node_to_nid(dn);
        if (likely((nid) >= 0)) {
                if (!node_online(nid)) {
                        if (register_node(nid)) {
                                pr_err("PCI: Failed to register node %d\n", nid);
                        } else {
                                update_numa_distance(dn);
                                node_set_online(nid);
                        }
                }
        }

        phb = pcibios_alloc_controller(dn);
        if (!phb)
                return NULL;
        rtas_setup_phb(phb);
        pci_process_bridge_OF_ranges(phb, dn, 0);
        phb->controller_ops = pseries_pci_controller_ops;

        pci_devs_phb_init_dynamic(phb);

        pseries_msi_allocate_domains(phb);

        ppc_iommu_register_device(phb);

        /* Create EEH devices for the PHB */
        eeh_phb_pe_create(phb);

        if (dn->child)
                pseries_eeh_init_edev_recursive(PCI_DN(dn));

        pcibios_scan_phb(phb);
        pcibios_finish_adding_to_bus(phb->bus);

        return phb;
}
EXPORT_SYMBOL_GPL(init_phb_dynamic);

/* RPA-specific bits for removing PHBs */
int remove_phb_dynamic(struct pci_controller *phb)
{
        struct pci_bus *b = phb->bus;
        struct pci_host_bridge *host_bridge = to_pci_host_bridge(b->bridge);
        struct resource *res;
        int rc, i;

        pr_debug("PCI: Removing PHB %04x:%02x...\n",
                 pci_domain_nr(b), b->number);

        /* We cannot to remove a root bus that has children */
        if (!(list_empty(&b->children) && list_empty(&b->devices)))
                return -EBUSY;

        /* We -know- there aren't any child devices anymore at this stage
         * and thus, we can safely unmap the IO space as it's not in use
         */
        res = &phb->io_resource;
        if (res->flags & IORESOURCE_IO) {
                rc = pcibios_unmap_io_space(b);
                if (rc) {
                        printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
                               __func__, b->name);
                        return 1;
                }
        }

        ppc_iommu_unregister_device(phb);

        pseries_msi_free_domains(phb);

        /* Keep a reference so phb isn't freed yet */
        get_device(&host_bridge->dev);

        /* Remove the PCI bus and unregister the bridge device from sysfs */
        phb->bus = NULL;
        pci_remove_bus(b);
        host_bridge->bus = NULL;
        device_unregister(&host_bridge->dev);

        /* Now release the IO resource */
        if (res->flags & IORESOURCE_IO)
                release_resource(res);

        /* Release memory resources */
        for (i = 0; i < 3; ++i) {
                res = &phb->mem_resources[i];
                if (!(res->flags & IORESOURCE_MEM))
                        continue;
                release_resource(res);
        }

        /*
         * The pci_controller data structure is freed by
         * the pcibios_free_controller_deferred() callback;
         * see pseries_root_bridge_prepare().
         */
        put_device(&host_bridge->dev);

        return 0;
}
EXPORT_SYMBOL_GPL(remove_phb_dynamic);