/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018 Andrew Turner
 * All rights reserved.
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * 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 "opt_platform.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/pcpu.h>
#include <sys/systm.h>

#include <machine/cpu.h>

#include <dev/psci/psci.h>
#include <dev/psci/smccc.h>

typedef void (cpu_quirk_install)(void);
struct cpu_quirks {
        cpu_quirk_install *quirk_install;
        u_int           midr_mask;
        u_int           midr_value;
#define CPU_QUIRK_POST_DEVICE   (1 << 0)        /* After device attach */
                                                /* e.g. needs SMCCC */
        u_int           flags;
};

static cpu_quirk_install install_thunderx_bcast_tlbi_workaround;

static struct cpu_quirks cpu_quirks[] = {
        {
                .midr_mask = CPU_IMPL_MASK | CPU_PART_MASK,
                .midr_value =
                    CPU_ID_RAW(CPU_IMPL_CAVIUM, CPU_PART_THUNDERX, 0, 0),
                .quirk_install = install_thunderx_bcast_tlbi_workaround,
        },
        {
                .midr_mask = CPU_IMPL_MASK | CPU_PART_MASK,
                .midr_value =
                    CPU_ID_RAW(CPU_IMPL_CAVIUM, CPU_PART_THUNDERX_81XX, 0, 0),
                .quirk_install = install_thunderx_bcast_tlbi_workaround,
        },
};

/*
 * Workaround Cavium erratum 27456.
 *
 * Invalidate the local icache when changing address spaces.
 */
static void
install_thunderx_bcast_tlbi_workaround(void)
{
        u_int midr;

        midr = get_midr();
        if (CPU_PART(midr) == CPU_PART_THUNDERX_81XX)
                PCPU_SET(bcast_tlbi_workaround, 1);
        else if (CPU_PART(midr) == CPU_PART_THUNDERX) {
                if (CPU_VAR(midr) == 0) {
                        /* ThunderX 1.x */
                        PCPU_SET(bcast_tlbi_workaround, 1);
                } else if (CPU_VAR(midr) == 1 && CPU_REV(midr) <= 1) {
                        /* ThunderX 2.0 - 2.1 */
                        PCPU_SET(bcast_tlbi_workaround, 1);
                }
        }
}

static void
install_cpu_errata_flags(u_int mask, u_int flags)
{
        u_int midr;
        size_t i;

        midr = get_midr();

        for (i = 0; i < nitems(cpu_quirks); i++) {
                if ((midr & cpu_quirks[i].midr_mask) ==
                    cpu_quirks[i].midr_value &&
                    (cpu_quirks[i].flags & mask) == flags) {
                        cpu_quirks[i].quirk_install();
                }
        }
}

/*
 * Install any CPU errata we need. On CPU 0 we only install the errata that
 * don't depend on device drivers as this is called early in the boot process.
 * On other CPUs the device drivers have already attached so install all
 * applicable errata.
 */
void
install_cpu_errata(void)
{
        /*
         * Only install early CPU errata on CPU 0, device drivers may not
         * have attached and some workarounds depend on them, e.g. to query
         * SMCCC.
         */
        if (PCPU_GET(cpuid) == 0) {
                install_cpu_errata_flags(CPU_QUIRK_POST_DEVICE, 0);
        } else {
                install_cpu_errata_flags(0, 0);
        }
}

/*
 * Install any errata workarounds that depend on device drivers, e.g. use
 * SMCCC to install a workaround.
 */
static void
install_cpu_errata_late(void *dummy __unused)
{
        MPASS(PCPU_GET(cpuid) == 0);
        install_cpu_errata_flags(CPU_QUIRK_POST_DEVICE, CPU_QUIRK_POST_DEVICE);
}
SYSINIT(install_cpu_errata_late, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE,
    install_cpu_errata_late, NULL);