/*-
 * Copyright (c) 2016 The FreeBSD Foundation
 * Copyright (c) 2022 Arm Ltd
 *
 * This software was developed by Andrew Turner under
 * the sponsorship of the FreeBSD Foundation.
 *
 * 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/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/rman.h>

#include <machine/intr.h>
#include <machine/resource.h>

#include <contrib/dev/acpica/include/acpi.h>
#include <dev/acpica/acpivar.h>

#include "gic_v3_reg.h"
#include "gic_v3_var.h"

#define GICV3_PRIV_VGIC         0x80000000
#define GICV3_PRIV_FLAGS        0x80000000
#define HV_MSI_SPI_START        64
#define HV_MSI_SPI_LAST         0

struct gic_v3_acpi_devinfo {
        struct gic_v3_devinfo   di_gic_dinfo;
        struct resource_list    di_rl;
};

static device_identify_t gic_v3_acpi_identify;
static device_probe_t gic_v3_acpi_probe;
static device_attach_t gic_v3_acpi_attach;
static bus_get_resource_list_t gic_v3_acpi_get_resource_list;

static void gic_v3_acpi_bus_attach(device_t);

static device_method_t gic_v3_acpi_methods[] = {
        /* Device interface */
        DEVMETHOD(device_identify,              gic_v3_acpi_identify),
        DEVMETHOD(device_probe,                 gic_v3_acpi_probe),
        DEVMETHOD(device_attach,                gic_v3_acpi_attach),

        /* Bus interface */
        DEVMETHOD(bus_get_resource_list,        gic_v3_acpi_get_resource_list),

        /* End */
        DEVMETHOD_END
};

DEFINE_CLASS_1(gic, gic_v3_acpi_driver, gic_v3_acpi_methods,
    sizeof(struct gic_v3_softc), gic_v3_driver);

EARLY_DRIVER_MODULE(gic_v3, acpi, gic_v3_acpi_driver, 0, 0,
    BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);

struct madt_table_data {
        device_t parent;
        device_t dev;
        ACPI_MADT_GENERIC_DISTRIBUTOR *dist;
        int count;
        bool rdist_use_gicc;
        bool have_vgic;
};

static void
madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        struct madt_table_data *madt_data;

        madt_data = (struct madt_table_data *)arg;

        switch(entry->Type) {
        case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
                if (madt_data->dist != NULL) {
                        if (bootverbose)
                                device_printf(madt_data->parent,
                                    "gic: Already have a distributor table");
                        break;
                }
                madt_data->dist = (ACPI_MADT_GENERIC_DISTRIBUTOR *)entry;
                break;

        case ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR:
                break;

        default:
                break;
        }
}

static void
rdist_map(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        ACPI_MADT_GENERIC_REDISTRIBUTOR *redist;
        ACPI_MADT_GENERIC_INTERRUPT *intr;
        struct madt_table_data *madt_data;
        rman_res_t count;

        madt_data = (struct madt_table_data *)arg;

        switch(entry->Type) {
        case ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR:
                if (madt_data->rdist_use_gicc)
                        break;
                redist = (ACPI_MADT_GENERIC_REDISTRIBUTOR *)entry;

                madt_data->count++;
                BUS_SET_RESOURCE(madt_data->parent, madt_data->dev,
                    SYS_RES_MEMORY, madt_data->count, redist->BaseAddress,
                    redist->Length);
                break;

        case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
                if (!madt_data->rdist_use_gicc)
                        break;

                intr = (ACPI_MADT_GENERIC_INTERRUPT *)entry;

                madt_data->count++;
                /*
                 * Map the two 64k redistributor frames.
                 */
                count = GICR_RD_BASE_SIZE + GICR_SGI_BASE_SIZE;
                if (madt_data->dist->Version == ACPI_MADT_GIC_VERSION_V4)
                        count += GICR_VLPI_BASE_SIZE + GICR_RESERVED_SIZE;
                BUS_SET_RESOURCE(madt_data->parent, madt_data->dev,
                    SYS_RES_MEMORY, madt_data->count, intr->GicrBaseAddress,
                    count);
                if (intr->VgicInterrupt == 0)
                        madt_data->have_vgic = false;

        default:
                break;
        }
}

static void
gic_v3_acpi_identify(driver_t *driver, device_t parent)
{
        struct madt_table_data madt_data;
        ACPI_TABLE_MADT *madt;
        vm_paddr_t physaddr;
        uintptr_t private;
        device_t dev;

        physaddr = acpi_find_table(ACPI_SIG_MADT);
        if (physaddr == 0)
                return;

        madt = acpi_map_table(physaddr, ACPI_SIG_MADT);
        if (madt == NULL) {
                device_printf(parent, "gic: Unable to map the MADT\n");
                return;
        }

        madt_data.parent = parent;
        madt_data.dist = NULL;
        madt_data.count = 0;

        acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
            madt_handler, &madt_data);
        if (madt_data.dist == NULL) {
                device_printf(parent,
                    "No gic interrupt or distributor table\n");
                goto out;
        }

        /* Check the GIC version is supported by thiss driver */
        switch(madt_data.dist->Version) {
        case ACPI_MADT_GIC_VERSION_V3:
        case ACPI_MADT_GIC_VERSION_V4:
                break;
        default:
                goto out;
        }

        dev = BUS_ADD_CHILD(parent, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE,
            "gic", -1);
        if (dev == NULL) {
                device_printf(parent, "add gic child failed\n");
                goto out;
        }

        /* Add the MADT data */
        BUS_SET_RESOURCE(parent, dev, SYS_RES_MEMORY, 0,
            madt_data.dist->BaseAddress, GICD_SIZE);

        madt_data.dev = dev;
        madt_data.rdist_use_gicc = false;
        madt_data.have_vgic = true;
        acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
            rdist_map, &madt_data);
        if (madt_data.count == 0) {
                /*
                 * No redistributors found, fall back to use the GICR
                 * address from the GICC sub-table.
                 */
                madt_data.rdist_use_gicc = true;
                acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
                    rdist_map, &madt_data);
        }

        private = madt_data.dist->Version;
        /* Flag that the VGIC is in use */
        if (madt_data.have_vgic)
                private |= GICV3_PRIV_VGIC;

        acpi_set_private(dev, (void *)private);

out:
        acpi_unmap_table(madt);
}

static int
gic_v3_acpi_probe(device_t dev)
{

        switch((uintptr_t)acpi_get_private(dev) & ~GICV3_PRIV_FLAGS) {
        case ACPI_MADT_GIC_VERSION_V3:
        case ACPI_MADT_GIC_VERSION_V4:
                break;
        default:
                return (ENXIO);
        }

        device_set_desc(dev, GIC_V3_DEVSTR);
        return (BUS_PROBE_NOWILDCARD);
}

static void
madt_count_redistrib(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        struct gic_v3_softc *sc = arg;

        if (entry->Type == ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR)
                sc->gic_redists.nregions++;
}

static void
madt_count_gicc_redistrib(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        struct gic_v3_softc *sc = arg;

        if (entry->Type == ACPI_MADT_TYPE_GENERIC_INTERRUPT)
                sc->gic_redists.nregions++;
}

static int
gic_v3_acpi_count_regions(device_t dev)
{
        struct gic_v3_softc *sc;
        ACPI_TABLE_MADT *madt;
        vm_paddr_t physaddr;

        sc = device_get_softc(dev);

        physaddr = acpi_find_table(ACPI_SIG_MADT);
        if (physaddr == 0)
                return (ENXIO);

        madt = acpi_map_table(physaddr, ACPI_SIG_MADT);
        if (madt == NULL) {
                device_printf(dev, "Unable to map the MADT\n");
                return (ENXIO);
        }

        acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
            madt_count_redistrib, sc);
        /* Fall back to use the distributor GICR base address */
        if (sc->gic_redists.nregions == 0) {
                acpi_walk_subtables(madt + 1,
                    (char *)madt + madt->Header.Length,
                    madt_count_gicc_redistrib, sc);
                sc->gic_redists.single = true;
        }
        acpi_unmap_table(madt);

        return (sc->gic_redists.nregions > 0 ? 0 : ENXIO);
}

static int
gic_v3_acpi_attach(device_t dev)
{
        struct gic_v3_softc *sc;
        int err;

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

        err = gic_v3_acpi_count_regions(dev);
        if (err != 0)
                goto count_error;
        if (vm_guest == VM_GUEST_HV) {
                sc->gic_mbi_start = HV_MSI_SPI_START;
                sc->gic_mbi_end = HV_MSI_SPI_LAST;
        }
        err = gic_v3_attach(dev);
        if (err != 0)
                goto error;

        sc->gic_pic = intr_pic_register(dev, ACPI_INTR_XREF);
        if (sc->gic_pic == NULL) {
                device_printf(dev, "could not register PIC\n");
                err = ENXIO;
                goto error;
        }
        /*
         * Registering for MSI with SPI range, as this is
         * required for Hyper-V GIC to work in ARM64.
         */
        if (vm_guest == VM_GUEST_HV) {
                err = intr_msi_register(dev, ACPI_MSI_XREF);
                if (err) {
                        device_printf(dev, "could not register MSI\n");
                        goto error;
                }
        }

        err = intr_pic_claim_root(dev, ACPI_INTR_XREF, arm_gic_v3_intr, sc,
            INTR_ROOT_IRQ);
        if (err != 0) {
                err = ENXIO;
                goto error;
        }

#ifdef SMP
        err = intr_ipi_pic_register(dev, 0);
        if (err != 0) {
                device_printf(dev, "could not register for IPIs\n");
                goto error;
        }
#endif

        /*
         * Try to register the ITS driver to this GIC. The GIC will act as
         * a bus in that case. Failure here will not affect the main GIC
         * functionality.
         */
        gic_v3_acpi_bus_attach(dev);

        if (device_get_children(dev, &sc->gic_children, &sc->gic_nchildren) !=0)
                sc->gic_nchildren = 0;

        return (0);

error:
        /* Failure so free resources */
        gic_v3_detach(dev);
count_error:
        if (bootverbose) {
                device_printf(dev,
                    "Failed to attach. Error %d\n", err);
        }

        return (err);
}

static void
gic_v3_add_children(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        ACPI_MADT_GENERIC_TRANSLATOR *gict;
        struct gic_v3_acpi_devinfo *di;
        struct gic_v3_softc *sc;
        device_t child, dev;
        u_int xref;
        int err, pxm;

        if (entry->Type == ACPI_MADT_TYPE_GENERIC_TRANSLATOR) {
                /* We have an ITS, add it as a child */
                gict = (ACPI_MADT_GENERIC_TRANSLATOR *)entry;
                dev = arg;
                sc = device_get_softc(dev);

                di = malloc(sizeof(*di), M_GIC_V3, M_WAITOK | M_ZERO);
                err = acpi_iort_its_lookup(gict->TranslationId, &xref, &pxm);
                if (err != 0) {
                        free(di, M_GIC_V3);
                        return;
                }

                child = device_add_child(dev, "its", DEVICE_UNIT_ANY);
                if (child == NULL) {
                        free(di, M_GIC_V3);
                        return;
                }

                di->di_gic_dinfo.gic_domain = pxm;
                di->di_gic_dinfo.msi_xref = xref;
                resource_list_init(&di->di_rl);
                resource_list_add(&di->di_rl, SYS_RES_MEMORY, 0,
                    gict->BaseAddress, gict->BaseAddress + 128 * 1024 - 1,
                    128 * 1024);
                sc->gic_nchildren++;
                device_set_ivars(child, di);
        }
}

static void
gic_v3_acpi_bus_attach(device_t dev)
{
        struct gic_v3_acpi_devinfo *di;
        struct gic_v3_softc *sc;
        ACPI_TABLE_MADT *madt;
        device_t child;
        vm_paddr_t physaddr;

        sc = device_get_softc(dev);

        physaddr = acpi_find_table(ACPI_SIG_MADT);
        if (physaddr == 0)
                return;

        madt = acpi_map_table(physaddr, ACPI_SIG_MADT);
        if (madt == NULL) {
                device_printf(dev, "Unable to map the MADT to add children\n");
                return;
        }

        acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
            gic_v3_add_children, dev);
        /* Add the vgic child if needed */
        if (((uintptr_t)acpi_get_private(dev) & GICV3_PRIV_FLAGS) != 0) {
                child = device_add_child(dev, "vgic", DEVICE_UNIT_ANY);
                if (child == NULL) {
                        device_printf(dev, "Could not add vgic child\n");
                } else {
                        di = malloc(sizeof(*di), M_GIC_V3, M_WAITOK | M_ZERO);
                        resource_list_init(&di->di_rl);
                        di->di_gic_dinfo.gic_domain = -1;
                        di->di_gic_dinfo.is_vgic = 1;
                        device_set_ivars(child, di);
                        sc->gic_nchildren++;
                }
        }

        acpi_unmap_table(madt);

        bus_attach_children(dev);
}

static struct resource_list *
gic_v3_acpi_get_resource_list(device_t bus, device_t child)
{
        struct gic_v3_acpi_devinfo *di;

        di = device_get_ivars(child);
        KASSERT(di != NULL, ("%s: No devinfo", __func__));

        return (&di->di_rl);
}