/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2011 NetApp, Inc.
 * Copyright (c) 2018 Joyent, Inc.
 * Copyright 2021 Oxide Computer Company
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef __FreeBSD__
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <strings.h>
#include <err.h>
#endif

#include <stdlib.h>

#include "config.h"
#include "pci_emul.h"
#ifndef __FreeBSD__
#include "bhyverun.h"
#endif

#ifndef __FreeBSD__
static struct pci_hostbridge_model {
        const char      *phm_model;
        uint16_t        phm_vendor;
        uint16_t        phm_device;
} pci_hb_models[] = {
        { "amd",        0x1022, 0x7432 }, /* AMD/made-up */
        { "netapp",     0x1275, 0x1275 }, /* NetApp/NetApp */
        { "i440fx",     0x8086, 0x1237 }, /* Intel/82441 */
        { "q35",        0x8086, 0x29b0 }, /* Intel/Q35 HB */
};

#define NUM_HB_MODELS   (sizeof (pci_hb_models) / sizeof (pci_hb_models[0]))
#endif

static int
pci_hostbridge_init(struct pci_devinst *pi, nvlist_t *nvl)
{
        const char *value;
        u_int vendor, device;

#ifdef __FreeBSD__
        vendor = 0x1275;        /* NetApp */
        device = 0x1275;        /* NetApp */
#else
        vendor = device = 0;
#endif

        value = get_config_value_node(nvl, "vendor");
        if (value != NULL)
                vendor = strtol(value, NULL, 0);
        else
                vendor = pci_config_read_reg(NULL, nvl, PCIR_VENDOR, 2, vendor);
        value = get_config_value_node(nvl, "devid");
        if (value != NULL)
                device = strtol(value, NULL, 0);
        else
                device = pci_config_read_reg(NULL, nvl, PCIR_DEVICE, 2, device);

#ifndef __FreeBSD__
        const char *model = get_config_value_node(nvl, "model");

        if (model != NULL && (vendor != 0 || device != 0)) {
                warnx("pci_hostbridge: cannot specify model and vendor/device");
                return (-1);
        } else if ((vendor != 0 && device == 0) ||
            (vendor == 0 && device != 0)) {
                warnx("pci_hostbridge: must specify both vendor and "
                    "device for custom hostbridge");
                return (-1);
        }
        if (model == NULL && vendor == 0 && device == 0)
                model = "netapp";

        if (model != NULL) {
                for (uint_t i = 0; i < NUM_HB_MODELS; i++) {
                        if (strcmp(model, pci_hb_models[i].phm_model) != 0)
                                continue;

                        /* found a model match */
                        vendor = pci_hb_models[i].phm_vendor;
                        device = pci_hb_models[i].phm_device;
                        break;
                }
                if (vendor == 0) {
                        warnx("pci_hostbridge: invalid model '%s'", model);
                        return (-1);
                }
        }

        /* Both i440fx and Q35 chipsets feature the concept of Programmable
         * Address Memory (PAM), where certain physical address ranges can be
         * configured to direct reads/writes to either DRAM, or to the PCI MMIO
         * space instead.  At boot, they default to bypassing DRAM, so in order
         * to cheaply paper over our lack of emulation, the memory in PAM0
         * (0xf0000-0xfffff, the System BIOS segment) should be zeroed.
         *
         * If this emulation is expanded in the future to truly support PAM
         * behavior, this hack can be removed.
         */
        if (vendor == 0x8086 && (device == 0x1237 || device == 0x29b0)) {
                const uintptr_t start = 0xf0000;
                const size_t len = 0x10000;
                void *system_bios_region = paddr_guest2host(pi->pi_vmctx,
                    start, len);
                assert(system_bios_region != NULL);
                bzero(system_bios_region, len);
        }
#endif /* !__FreeBSD__ */

        /* config space */
        pci_set_cfgdata16(pi, PCIR_VENDOR, vendor);
        pci_set_cfgdata16(pi, PCIR_DEVICE, device);
        pci_set_cfgdata8(pi, PCIR_HDRTYPE, PCIM_HDRTYPE_NORMAL);
        pci_set_cfgdata8(pi, PCIR_CLASS, PCIC_BRIDGE);
        pci_set_cfgdata8(pi, PCIR_SUBCLASS, PCIS_BRIDGE_HOST);

        pci_emul_add_pciecap(pi, PCIEM_TYPE_ROOT_PORT);

        return (0);
}

static int
pci_amd_hostbridge_legacy_config(nvlist_t *nvl, const char *opts __unused)
{
        nvlist_t *pci_regs;

        pci_regs = create_relative_config_node(nvl, "pcireg");
        if (pci_regs == NULL) {
                warnx("amd_hostbridge: failed to create pciregs node");
                return (-1);
        }
        set_config_value_node(pci_regs, "vendor", "0x1022");    /* AMD */
        set_config_value_node(pci_regs, "device", "0x7432");    /* made up */

        return (0);
}

static const struct pci_devemu pci_de_amd_hostbridge = {
        .pe_emu = "amd_hostbridge",
        .pe_legacy_config = pci_amd_hostbridge_legacy_config,
        .pe_alias = "hostbridge",
};
PCI_EMUL_SET(pci_de_amd_hostbridge);

static const struct pci_devemu pci_de_hostbridge = {
        .pe_emu = "hostbridge",
        .pe_init = pci_hostbridge_init,
};
PCI_EMUL_SET(pci_de_hostbridge);