// SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/range.h>

#include "bus_numa.h"

LIST_HEAD(pci_root_infos);

static struct pci_root_info *x86_find_pci_root_info(int bus)
{
        struct pci_root_info *info;

        list_for_each_entry(info, &pci_root_infos, list)
                if (info->busn.start == bus)
                        return info;

        return NULL;
}

int x86_pci_root_bus_node(int bus)
{
        struct pci_root_info *info = x86_find_pci_root_info(bus);

        if (!info)
                return NUMA_NO_NODE;

        return info->node;
}

void x86_pci_root_bus_resources(int bus, struct list_head *resources)
{
        struct pci_root_info *info = x86_find_pci_root_info(bus);
        struct pci_root_res *root_res;
        struct resource_entry *window;
        bool found = false;

        if (!info)
                goto default_resources;

        printk(KERN_DEBUG "PCI: root bus %02x: hardware-probed resources\n",
               bus);

        /* already added by acpi ? */
        resource_list_for_each_entry(window, resources)
                if (window->res->flags & IORESOURCE_BUS) {
                        found = true;
                        break;
                }

        if (!found)
                pci_add_resource(resources, &info->busn);

        list_for_each_entry(root_res, &info->resources, list)
                pci_add_resource(resources, &root_res->res);

        return;

default_resources:
        /*
         * We don't have any host bridge aperture information from the
         * "native host bridge drivers," e.g., amd_bus or broadcom_bus,
         * so fall back to the defaults historically used by pci_create_bus().
         */
        printk(KERN_DEBUG "PCI: root bus %02x: using default resources\n", bus);
        pci_add_resource(resources, &ioport_resource);
        pci_add_resource(resources, &iomem_resource);
}

struct pci_root_info __init *alloc_pci_root_info(int bus_min, int bus_max,
                                                 int node, int link)
{
        struct pci_root_info *info;

        info = kzalloc_obj(*info);

        if (!info)
                return info;

        sprintf(info->name, "PCI Bus #%02x", bus_min);

        INIT_LIST_HEAD(&info->resources);
        info->busn.name  = info->name;
        info->busn.start = bus_min;
        info->busn.end   = bus_max;
        info->busn.flags = IORESOURCE_BUS;
        info->node = node;
        info->link = link;

        list_add_tail(&info->list, &pci_root_infos);

        return info;
}

void update_res(struct pci_root_info *info, resource_size_t start,
                resource_size_t end, unsigned long flags, int merge)
{
        struct resource *res;
        struct pci_root_res *root_res;

        if (start > end)
                return;

        if (start == RESOURCE_SIZE_MAX)
                return;

        if (!merge)
                goto addit;

        /* try to merge it with old one */
        list_for_each_entry(root_res, &info->resources, list) {
                resource_size_t final_start, final_end;
                resource_size_t common_start, common_end;

                res = &root_res->res;
                if (res->flags != flags)
                        continue;

                common_start = max(res->start, start);
                common_end = min(res->end, end);
                if (common_start > common_end + 1)
                        continue;

                final_start = min(res->start, start);
                final_end = max(res->end, end);

                res->start = final_start;
                res->end = final_end;
                return;
        }

addit:

        /* need to add that */
        root_res = kzalloc_obj(*root_res);
        if (!root_res)
                return;

        res = &root_res->res;
        res->name = info->name;
        res->flags = flags;
        res->start = start;
        res->end = end;

        list_add_tail(&root_res->list, &info->resources);
}