/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2019-2020 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.
 */

#include "opt_acpi.h"

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/bitstring.h>
#include <sys/kernel.h>
#include <sys/rman.h>
#include <sys/tree.h>
#include <sys/taskqueue.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <contrib/dev/acpica/include/acpi.h>
#include <dev/acpica/acpivar.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/iommu/iommu.h>

#include <arm64/iommu/iommu.h>

#include "smmuvar.h"

#define MEMORY_RESOURCE_SIZE    0x20000
#define MAX_SMMU                8

struct smmu_acpi_devinfo {
        struct resource_list    di_rl;
};

struct iort_table_data {
        device_t parent;
        device_t dev;
        ACPI_IORT_SMMU_V3 *smmu[MAX_SMMU];
        int count;
};

static void
iort_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        struct iort_table_data *iort_data;
        ACPI_IORT_NODE *node;
        int i;

        iort_data = (struct iort_table_data *)arg;
        i = iort_data->count;

        switch(entry->Type) {
        case ACPI_IORT_NODE_SMMU_V3:
                if (i == MAX_SMMU) {
                        printf("SMMUv3 found, but no space available.\n");
                        break;
                }

                if (iort_data->smmu[i] != NULL) {
                        if (bootverbose)
                                device_printf(iort_data->parent,
                                    "smmu: Already have an SMMU table");
                        break;
                }
                node = (ACPI_IORT_NODE *)entry;
                iort_data->smmu[i] = (ACPI_IORT_SMMU_V3 *)node->NodeData;
                iort_data->count++;
                break;
        default:
                break;
        }
}

static void
smmu_acpi_identify(driver_t *driver, device_t parent)
{
        struct iort_table_data iort_data;
        ACPI_TABLE_IORT *iort;
        vm_paddr_t iort_pa;
        uintptr_t priv;
        device_t dev;
        int i;

        iort_pa = acpi_find_table(ACPI_SIG_IORT);
        if (iort_pa == 0)
                return;

        iort = acpi_map_table(iort_pa, ACPI_SIG_IORT);
        if (iort == NULL) {
                device_printf(parent, "smmu: Unable to map the IORT\n");
                return;
        }

        iort_data.parent = parent;
        for (i = 0; i < MAX_SMMU; i++)
                iort_data.smmu[i] = NULL;
        iort_data.count = 0;

        acpi_walk_subtables(iort + 1, (char *)iort + iort->Header.Length,
            iort_handler, &iort_data);
        if (iort_data.count == 0) {
                device_printf(parent, "No SMMU found.\n");
                goto out;
        }

        for (i = 0; i < iort_data.count; i++) {
                dev = BUS_ADD_CHILD(parent,
                    BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE, "smmu", -1);
                if (dev == NULL) {
                        device_printf(parent, "add smmu child failed\n");
                        goto out;
                }

                /* Add the IORT data */
                BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 0,
                    iort_data.smmu[i]->EventGsiv, 1);
                BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 1,
                    iort_data.smmu[i]->PriGsiv, 1);
                BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 2,
                    iort_data.smmu[i]->SyncGsiv, 1);
                BUS_SET_RESOURCE(parent, dev, SYS_RES_IRQ, 3,
                    iort_data.smmu[i]->GerrGsiv, 1);
                BUS_SET_RESOURCE(parent, dev, SYS_RES_MEMORY, 0,
                    iort_data.smmu[i]->BaseAddress, MEMORY_RESOURCE_SIZE);

                priv = iort_data.smmu[i]->Flags;
                priv <<= 32;
                priv |= iort_data.smmu[i]->Model;

                acpi_set_private(dev, (void *)priv);
        }

        iort_data.dev = dev;

out:
        acpi_unmap_table(iort);
}

static int
smmu_acpi_probe(device_t dev)
{

        switch((uintptr_t)acpi_get_private(dev) & 0xffffffff) {
        case ACPI_IORT_SMMU_V3_GENERIC:
                /* Generic SMMUv3 */
                break;
        default:
                return (ENXIO);
        }

        device_set_desc(dev, SMMU_DEVSTR);

        return (BUS_PROBE_NOWILDCARD);
}

static int
smmu_acpi_attach(device_t dev)
{
        struct smmu_softc *sc;
        struct smmu_unit *unit;
        struct iommu_unit *iommu;
        uintptr_t priv;
        int err;
        int rid;

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

        priv = (uintptr_t)acpi_get_private(dev);
        if ((priv >> 32) & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE)
                sc->features |= SMMU_FEATURE_COHERENCY;

        if (bootverbose)
                device_printf(sc->dev, "%s: features %x\n",
                    __func__, sc->features);

        rid = 0;
        sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
            RF_ACTIVE);
        if (sc->res[0] == NULL) {
                device_printf(dev, "Can't allocate memory resource.\n");
                err = ENXIO;
                goto error;
        }

        /*
         * Interrupt lines are "eventq", "priq", "cmdq-sync", "gerror".
         */

        rid = 0;
        sc->res[1] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
        if (sc->res[1] == NULL) {
                device_printf(dev, "Can't allocate eventq IRQ resource.\n");
                err = ENXIO;
                goto error;
        }

        rid = 2;
        sc->res[3] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
        if (sc->res[3] == NULL) {
                device_printf(dev, "Can't allocate cmdq-sync IRQ resource.\n");
                err = ENXIO;
                goto error;
        }

        rid = 3;
        sc->res[4] = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid, RF_ACTIVE);
        if (sc->res[4] == NULL) {
                device_printf(dev, "Can't allocate gerror IRQ resource.\n");
                err = ENXIO;
                goto error;
        }

        err = smmu_attach(dev);
        if (err != 0)
                goto error;

        unit = &sc->unit;
        unit->dev = dev;

        iommu = &unit->iommu;
        iommu->dev = dev;

        LIST_INIT(&unit->domain_list);

        /* Use memory start address as an xref. */
        sc->xref = bus_get_resource_start(dev, SYS_RES_MEMORY, 0);

        err = iommu_register(iommu);
        if (err) {
                device_printf(dev, "Failed to register SMMU.\n");
                return (ENXIO);
        }

        return (0);

error:
        if (bootverbose) {
                device_printf(dev,
                    "Failed to attach. Error %d\n", err);
        }
        /* Failure so free resources. */
        smmu_detach(dev);

        return (err);
}

static device_method_t smmu_acpi_methods[] = {
        /* Device interface */
        DEVMETHOD(device_identify,              smmu_acpi_identify),
        DEVMETHOD(device_probe,                 smmu_acpi_probe),
        DEVMETHOD(device_attach,                smmu_acpi_attach),

        /* End */
        DEVMETHOD_END
};

DEFINE_CLASS_1(smmu, smmu_acpi_driver, smmu_acpi_methods,
    sizeof(struct smmu_softc), smmu_driver);

EARLY_DRIVER_MODULE(smmu, acpi, smmu_acpi_driver, 0, 0,
    BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);