// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Read address ranges from a Broadcom CNB20LE Host Bridge
 *
 * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
 */

#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <asm/pci_x86.h>
#include <asm/pci-direct.h>

#include "bus_numa.h"

static void __init cnb20le_res(u8 bus, u8 slot, u8 func)
{
        struct pci_root_info *info;
        struct pci_root_res *root_res;
        struct resource res;
        u16 word1, word2;
        u8 fbus, lbus;

        /* read the PCI bus numbers */
        fbus = read_pci_config_byte(bus, slot, func, 0x44);
        lbus = read_pci_config_byte(bus, slot, func, 0x45);
        info = alloc_pci_root_info(fbus, lbus, 0, 0);

        /*
         * Add the legacy IDE ports on bus 0
         *
         * These do not exist anywhere in the bridge registers, AFAICT. I do
         * not have the datasheet, so this is the best I can do.
         */
        if (fbus == 0) {
                update_res(info, 0x01f0, 0x01f7, IORESOURCE_IO, 0);
                update_res(info, 0x03f6, 0x03f6, IORESOURCE_IO, 0);
                update_res(info, 0x0170, 0x0177, IORESOURCE_IO, 0);
                update_res(info, 0x0376, 0x0376, IORESOURCE_IO, 0);
                update_res(info, 0xffa0, 0xffaf, IORESOURCE_IO, 0);
        }

        /* read the non-prefetchable memory window */
        word1 = read_pci_config_16(bus, slot, func, 0xc0);
        word2 = read_pci_config_16(bus, slot, func, 0xc2);
        if (word1 != word2) {
                res.start = ((resource_size_t) word1 << 16) | 0x0000;
                res.end   = ((resource_size_t) word2 << 16) | 0xffff;
                res.flags = IORESOURCE_MEM;
                update_res(info, res.start, res.end, res.flags, 0);
        }

        /* read the prefetchable memory window */
        word1 = read_pci_config_16(bus, slot, func, 0xc4);
        word2 = read_pci_config_16(bus, slot, func, 0xc6);
        if (word1 != word2) {
                res.start = ((resource_size_t) word1 << 16) | 0x0000;
                res.end   = ((resource_size_t) word2 << 16) | 0xffff;
                res.flags = IORESOURCE_MEM | IORESOURCE_PREFETCH;
                update_res(info, res.start, res.end, res.flags, 0);
        }

        /* read the IO port window */
        word1 = read_pci_config_16(bus, slot, func, 0xd0);
        word2 = read_pci_config_16(bus, slot, func, 0xd2);
        if (word1 != word2) {
                res.start = word1;
                res.end   = word2;
                res.flags = IORESOURCE_IO;
                update_res(info, res.start, res.end, res.flags, 0);
        }

        /* print information about this host bridge */
        res.start = fbus;
        res.end   = lbus;
        res.flags = IORESOURCE_BUS;
        printk(KERN_INFO "CNB20LE PCI Host Bridge (domain 0000 %pR)\n", &res);

        list_for_each_entry(root_res, &info->resources, list)
                printk(KERN_INFO "host bridge window %pR\n", &root_res->res);
}

static int __init broadcom_postcore_init(void)
{
        u8 bus = 0, slot = 0;
        u32 id;
        u16 vendor, device;

#ifdef CONFIG_ACPI
        /*
         * We should get host bridge information from ACPI unless the BIOS
         * doesn't support it.
         */
        if (!acpi_disabled && acpi_os_get_root_pointer())
                return 0;
#endif

        id = read_pci_config(bus, slot, 0, PCI_VENDOR_ID);
        vendor = id & 0xffff;
        device = (id >> 16) & 0xffff;

        if (vendor == PCI_VENDOR_ID_SERVERWORKS &&
            device == PCI_DEVICE_ID_SERVERWORKS_LE) {
                cnb20le_res(bus, slot, 0);
                cnb20le_res(bus, slot, 1);
        }
        return 0;
}

postcore_initcall(broadcom_postcore_init);