/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003 Matthew N. Dodd <winter@jurai.net>
 * 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/efi.h>

#include <sys/module.h>
#include <sys/bus.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <machine/md_var.h>
#if defined(__amd64__) || defined(__i386__)
#include <machine/pc/bios.h>
#endif
#include <dev/smbios/smbios.h>

/*
 * System Management BIOS Reference Specification, v2.4 Final
 * http://www.dmtf.org/standards/published_documents/DSP0134.pdf
 */

struct smbios_softc {
        device_t                dev;
        union {
                struct smbios_eps *     eps;
                struct smbios3_eps *    eps3;
        };
        bool is_eps3;
};

static void     smbios_identify (driver_t *, device_t);
static int      smbios_probe    (device_t);
static int      smbios_attach   (device_t);
static int      smbios_detach   (device_t);
static int      smbios_modevent (module_t, int, void *);

static int      smbios_cksum    (void *);
static bool     smbios_eps3     (void *);

static void
smbios_identify (driver_t *driver, device_t parent)
{
#ifdef ARCH_MAY_USE_EFI
        efi_guid_t efi_smbios = EFI_TABLE_SMBIOS;
        efi_guid_t efi_smbios3 = EFI_TABLE_SMBIOS3;
        void *addr_efi;
#endif
        struct smbios_eps *eps;
        struct smbios3_eps *eps3;
        void *ptr;
        device_t child;
        vm_paddr_t addr = 0;
        size_t map_size = sizeof(*eps);
        uint8_t length;

        if (!device_is_alive(parent))
                return;

#ifdef ARCH_MAY_USE_EFI
        if (!efi_get_table(&efi_smbios3, &addr_efi)) {
                addr = (vm_paddr_t)addr_efi;
                map_size = sizeof(*eps3);
        } else if (!efi_get_table(&efi_smbios, &addr_efi)) {
                addr = (vm_paddr_t)addr_efi;
        }

#endif

#if defined(__amd64__) || defined(__i386__)
        if (addr == 0) {
                addr = bios_sigsearch(SMBIOS_START, SMBIOS3_SIG, SMBIOS3_LEN,
                    SMBIOS_STEP, SMBIOS_OFF);
                if (addr != 0)
                        map_size = sizeof(*eps3);
                else
                        addr = bios_sigsearch(SMBIOS_START,
                            SMBIOS_SIG, SMBIOS_LEN, SMBIOS_STEP, SMBIOS_OFF);
        }
#endif

        if (addr == 0)
                return;

        ptr = pmap_mapbios(addr, map_size);
        if (ptr == NULL) {
                printf("smbios: Unable to map memory.\n");
                return;
        }
        if (map_size == sizeof(*eps3)) {
                eps3 = ptr;
                length = eps3->length;
                if (memcmp(eps3->anchor_string, SMBIOS3_SIG, SMBIOS3_LEN) != 0)
                        goto corrupt_sig;
        } else {
                eps = ptr;
                length = eps->length;
                if (memcmp(eps->anchor_string, SMBIOS_SIG, SMBIOS_LEN) != 0)
                        goto corrupt_sig;
        }
        if (length != map_size) {
                /*
                 * SMBIOS v2.1 implementations might use 0x1e because the
                 * standard was then erroneous.
                 */
                if (length == 0x1e && map_size == sizeof(*eps) &&
                    eps->major_version == 2 && eps->minor_version == 1)
                        length = map_size;
                else {
                        printf("smbios: %s-bit Entry Point: Invalid length: "
                            "Got %hhu, expected %zu\n",
                            map_size == sizeof(*eps3) ? "64" : "32",
                            length, map_size);
                        goto unmap_return;
                }
        }

        child = BUS_ADD_CHILD(parent, 5, "smbios", DEVICE_UNIT_ANY);
        device_set_driver(child, driver);

        /* smuggle the phys addr into probe and attach */
        bus_set_resource(child, SYS_RES_MEMORY, 0, addr, length);
        device_set_desc(child, "System Management BIOS");

unmap_return:
        pmap_unmapbios(ptr, map_size);
        return;

corrupt_sig:
        {
                const char *sig;
                const char *table_ver_str;
                size_t i, end;

                if (map_size == sizeof(*eps3)) {
                        sig = eps3->anchor_string;
                        table_ver_str = "64";
                        end = SMBIOS3_LEN;
                } else {
                        sig = eps->anchor_string;
                        table_ver_str = "32";
                        end = SMBIOS_LEN;
                }

                /* Space after ':' printed by the loop. */
                printf("smbios: %s-bit Entry Point: Corrupt signature (hex):",
                    table_ver_str);
                for (i = 0; i < end; ++i)
                        printf(" %02hhx", sig[i]);
                printf("\n");
        }
        goto unmap_return;
}

static int
smbios_probe (device_t dev)
{
        vm_paddr_t pa;
        vm_size_t size;
        void *va;
        int error;

        error = 0;

        pa = bus_get_resource_start(dev, SYS_RES_MEMORY, 0);
        size = bus_get_resource_count(dev, SYS_RES_MEMORY, 0);
        va = pmap_mapbios(pa, size);
        if (va == NULL) {
                device_printf(dev, "Unable to map memory.\n");
                return (ENOMEM);
        }

        if (smbios_cksum(va)) {
                device_printf(dev, "SMBIOS checksum failed.\n");
                error = ENXIO;
        }

        pmap_unmapbios(va, size);
        return (error);
}

static int
smbios_attach (device_t dev)
{
        struct smbios_softc *sc;
        void *va;
        vm_paddr_t pa;
        vm_size_t size;

        sc = device_get_softc(dev);
        sc->dev = dev;
        pa = bus_get_resource_start(dev, SYS_RES_MEMORY, 0);
        size = bus_get_resource_count(dev, SYS_RES_MEMORY, 0);
        va = pmap_mapbios(pa, size);
        if (va == NULL) {
                device_printf(dev, "Unable to map memory.\n");
                return (ENOMEM);
        }
        sc->is_eps3 = smbios_eps3(va);

        if (sc->is_eps3) {
                sc->eps3 = va;
                device_printf(dev, "Entry point: v3 (64-bit), Version: %u.%u\n",
                    sc->eps3->major_version, sc->eps3->minor_version);
                if (bootverbose)
                        device_printf(dev,
                            "Docrev: %u, Entry Point Revision: %u\n",
                            sc->eps3->docrev, sc->eps3->entry_point_revision);
        } else {
                const struct smbios_eps *const eps = va;
                const uint8_t bcd = eps->BCD_revision;

                sc->eps = va;
                device_printf(dev, "Entry point: v2.1 (32-bit), Version: %u.%u",
                    eps->major_version, eps->minor_version);
                if (bcd < LIBKERN_LEN_BCD2BIN && bcd2bin(bcd) != 0)
                        printf(", BCD Revision: %u.%u\n",
                            bcd2bin(bcd >> 4), bcd2bin(bcd & 0x0f));
                else
                        printf("\n");
                if (bootverbose)
                        device_printf(dev, "Entry Point Revision: %u\n",
                            eps->entry_point_revision);
        }
        return (0);
}

static int
smbios_detach (device_t dev)
{
        struct smbios_softc *sc;
        vm_size_t size;
        void *va;

        sc = device_get_softc(dev);
        va = (sc->is_eps3 ? (void *)sc->eps3 : (void *)sc->eps);
        if (sc->is_eps3)
                va = sc->eps3;
        else
                va = sc->eps;
        size = bus_get_resource_count(dev, SYS_RES_MEMORY, 0);

        if (va != NULL)
                pmap_unmapbios(va, size);

        return (0);
}

static int
smbios_modevent (module_t mod, int what, void *arg)
{
        device_t *      devs;
        int             count;
        int             i;

        switch (what) {
        case MOD_LOAD:
                break;
        case MOD_UNLOAD:
                devclass_get_devices(devclass_find("smbios"), &devs, &count);
                for (i = 0; i < count; i++) {
                        device_delete_child(device_get_parent(devs[i]), devs[i]);
                }
                free(devs, M_TEMP);
                break;
        default:
                break;
        }

        return (0);
}

static device_method_t smbios_methods[] = {
        /* Device interface */
        DEVMETHOD(device_identify,      smbios_identify),
        DEVMETHOD(device_probe,         smbios_probe),
        DEVMETHOD(device_attach,        smbios_attach),
        DEVMETHOD(device_detach,        smbios_detach),
        DEVMETHOD_END
};

static driver_t smbios_driver = {
        "smbios",
        smbios_methods,
        sizeof(struct smbios_softc),
};

DRIVER_MODULE(smbios, nexus, smbios_driver, smbios_modevent, NULL);
#ifdef ARCH_MAY_USE_EFI
MODULE_DEPEND(smbios, efirt, 1, 1, 1);
#endif
MODULE_VERSION(smbios, 1);


static bool
smbios_eps3 (void *v)
{
        struct smbios3_eps *e;

        e = (struct smbios3_eps *)v;
        return (memcmp(e->anchor_string, SMBIOS3_SIG, SMBIOS3_LEN) == 0);
}

static int
smbios_cksum (void *v)
{
        const u_int8_t *ptr;
        u_int8_t cksum;
        u_int8_t length;
        int i;

        if (smbios_eps3(v)) {
                const struct smbios3_eps *eps3 = v;

                length = eps3->length;
        } else {
                const struct smbios_eps *eps = v;

                length = eps->length;
        }
        ptr = v;
        cksum = 0;
        for (i = 0; i < length; i++)
                cksum += ptr[i];

        return (cksum);
}