/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2019 Ruslan Bukin <br@bsdpad.com>
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory (Department of Computer Science and
 * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
 * DARPA SSITH 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.
 */

/*
 * Intel Stratix 10 Service Layer
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/vmem.h>

#include <vm/vm.h>
#include <vm/pmap.h>

#include <dev/fdt/simplebus.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <arm64/intel/intel-smc.h>
#include <arm64/intel/stratix10-svc.h>

#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/intr.h>

struct s10_svc_softc {
        device_t                dev;
        vmem_t                  *vmem;
        intel_smc_callfn_t      callfn;
};

static int
s10_data_claim(struct s10_svc_softc *sc)
{
        struct arm_smccc_res res;
        register_t a0, a1, a2;
        int ret;

        ret = 0;

        while (1) {
                a0 = INTEL_SIP_SMC_FPGA_CONFIG_COMPLETED_WRITE;
                a1 = 0;
                a2 = 0;

                ret = sc->callfn(a0, a1, a2, 0, 0, 0, 0, 0, &res);
                if (ret == INTEL_SIP_SMC_FPGA_CONFIG_STATUS_BUSY)
                        continue;

                break;
        }

        return (ret);
}

int
s10_svc_send(device_t dev, struct s10_svc_msg *msg)
{
        struct s10_svc_softc *sc;
        struct arm_smccc_res res;
        register_t a0, a1, a2;
        int ret;

        sc = device_get_softc(dev);

        a0 = 0;
        a1 = 0;
        a2 = 0;

        switch (msg->command) {
        case COMMAND_RECONFIG:
                a0 = INTEL_SIP_SMC_FPGA_CONFIG_START;
                a1 = msg->flags;
                break;
        case COMMAND_RECONFIG_DATA_SUBMIT:
                a0 = INTEL_SIP_SMC_FPGA_CONFIG_WRITE;
                a1 = (uint64_t)msg->payload;
                a2 = (uint64_t)msg->payload_length;
                break;
        case COMMAND_RECONFIG_DATA_CLAIM:
                ret = s10_data_claim(sc);
                return (ret);
        default:
                return (-1);
        }

        ret = sc->callfn(a0, a1, a2, 0, 0, 0, 0, 0, &res);

        return (ret);
}

int
s10_svc_allocate_memory(device_t dev, struct s10_svc_mem *mem, int size)
{
        struct s10_svc_softc *sc;

        sc = device_get_softc(dev);

        if (size <= 0)
                return (EINVAL);

        if (vmem_alloc(sc->vmem, size,
            M_FIRSTFIT | M_NOWAIT, &mem->paddr)) {
                device_printf(dev, "Can't allocate memory\n");
                return (ENOMEM);
        }

        mem->size = size;
        mem->fill = 0;
        mem->vaddr = (vm_offset_t)pmap_mapdev(mem->paddr, mem->size);

        return (0);
}

void
s10_svc_free_memory(device_t dev, struct s10_svc_mem *mem)
{
        struct s10_svc_softc *sc;

        sc = device_get_softc(dev);

        vmem_free(sc->vmem, mem->paddr, mem->size);
}

static int
s10_get_memory(struct s10_svc_softc *sc)
{
        struct arm_smccc_res res;
        vmem_addr_t addr;
        vmem_size_t size;
        vmem_t *vmem;

        sc->callfn(INTEL_SIP_SMC_FPGA_CONFIG_GET_MEM,
            0, 0, 0, 0, 0, 0, 0, &res);
        if (res.a0 != INTEL_SIP_SMC_STATUS_OK)
                return (ENXIO);

        vmem = vmem_create("stratix10 vmem", 0, 0, PAGE_SIZE,
            PAGE_SIZE, M_BESTFIT | M_WAITOK);
        if (vmem == NULL)
                return (ENXIO);

        addr = res.a1;
        size = res.a2;

        device_printf(sc->dev, "Shared memory address 0x%lx size 0x%lx\n",
            addr, size);

        vmem_add(vmem, addr, size, 0);

        sc->vmem = vmem;

        return (0);
}

static intel_smc_callfn_t
s10_svc_get_callfn(struct s10_svc_softc *sc, phandle_t node)
{
        char method[16];

        if ((OF_getprop(node, "method", method, sizeof(method))) > 0) {
                if (strcmp(method, "hvc") == 0)
                        return (arm_smccc_hvc);
                else if (strcmp(method, "smc") == 0)
                        return (arm_smccc_smc);
                else
                        device_printf(sc->dev,
                            "Invalid method \"%s\"\n", method);
        } else
                device_printf(sc->dev, "SMC method not provided\n");

        return (NULL);
}

static int
s10_svc_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (!ofw_bus_is_compatible(dev, "intel,stratix10-svc"))
                return (ENXIO);

        device_set_desc(dev, "Stratix 10 SVC");

        return (BUS_PROBE_DEFAULT);
}

static int
s10_svc_attach(device_t dev)
{
        struct s10_svc_softc *sc;
        phandle_t node;

        node = ofw_bus_get_node(dev);

        sc = device_get_softc(dev);
        sc->dev = dev;

        if (device_get_unit(dev) != 0)
                return (ENXIO);

        sc->callfn = s10_svc_get_callfn(sc, node);
        if (sc->callfn == NULL)
                return (ENXIO);

        if (s10_get_memory(sc) != 0)
                return (ENXIO);

        return (0);
}

static device_method_t s10_svc_methods[] = {
        DEVMETHOD(device_probe,         s10_svc_probe),
        DEVMETHOD(device_attach,        s10_svc_attach),
        { 0, 0 }
};

static driver_t s10_svc_driver = {
        "s10_svc",
        s10_svc_methods,
        sizeof(struct s10_svc_softc),
};

EARLY_DRIVER_MODULE(s10_svc, simplebus, s10_svc_driver, 0, 0,
    BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);