/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2026 Ruslan Bukin <br@bsdpad.com>
 *
 * 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/types.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/bitstring.h>
#include <sys/kernel.h>
#include <sys/rman.h>
#include <sys/sysctl.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 <machine/bus.h>
#include <machine/resource.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <dev/iommu/iommu.h>
#include <riscv/iommu/iommu_pmap.h>
#include <riscv/iommu/iommu.h>
#include <riscv/iommu/iommu_frontend.h>

#define PCI_DEVICE_ID_REDHAT_RISCV_IOMMU        0x0014
#define PCI_VENDOR_ID_REDHAT                    0x1b36
#define PCI_DEVICE_ID_RIVOS_RISCV_IOMMU_GA      0x0008
#define PCI_VENDOR_ID_RIVOS                     0x1efd

static int
iommu_pci_probe(device_t dev)
{
        uint16_t vendor_id, device_id;

        vendor_id = pci_get_vendor(dev);
        device_id = pci_get_device(dev);

        if (vendor_id == PCI_VENDOR_ID_REDHAT &&
            device_id == PCI_DEVICE_ID_REDHAT_RISCV_IOMMU) {
                device_set_desc(dev, "RedHat IOMMU");
                return (BUS_PROBE_DEFAULT);
        }

        if (vendor_id == PCI_VENDOR_ID_RIVOS &&
            device_id == PCI_DEVICE_ID_RIVOS_RISCV_IOMMU_GA) {
                device_set_desc(dev, "Rivos IOMMU");
                return (BUS_PROBE_DEFAULT);
        }

        return (ENXIO);
}

static int
iommu_pci_attach(device_t dev)
{
        struct riscv_iommu_unit *unit;
        struct riscv_iommu_softc *sc;
        struct iommu_unit *iommu;
        phandle_t node;
        int count;
        int error;
        int rid;
        int i;

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

        node = ofw_bus_get_node(dev);

        pci_enable_busmaster(dev);

        rid = PCIR_BAR(0);
        sc->res[0] = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
            RF_ACTIVE);
        if (sc->res[0] == NULL) {
                device_printf(dev, "couldn't map memory\n");
                goto error;
        }

        count = 4;
        if (pci_alloc_msix(dev, &count) == 0) {
                for (i = 0; i < 4; i++) {
                        rid = i;
                        sc->res[1 + i] = bus_alloc_resource_any(dev,
                            SYS_RES_IRQ, &rid, RF_ACTIVE);
                        if (sc->res[i + 1] == NULL) {
                                device_printf(dev, "Can't allocate IRQ "
                                    " resource.\n");
                                goto error;
                        }
                }
        } else
                device_printf(dev, "Can't allocate MSI-X interrupts."
                    " Ignoring.\n");

        error = riscv_iommu_attach(dev);
        if (error)
                goto error;

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

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

        LIST_INIT(&unit->domain_list);

        sc->xref = OF_xref_from_node(node);

        error = iommu_register(iommu);
        if (error) {
                device_printf(dev, "Failed to register RISC-V IOMMU.\n");
                goto error;
        }

        return (0);

error:
        if (sc->res[0])
                bus_release_resource(dev, SYS_RES_MEMORY, PCIR_BAR(0),
                    sc->res[0]);

        for (i = 0; i < 4; i++)
                if (sc->res[i + 1])
                        bus_release_resource(dev, SYS_RES_IRQ, i,
                            sc->res[i + 1]);

        return (error);
}

static device_method_t riscv_iommu_pci_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         iommu_pci_probe),
        DEVMETHOD(device_attach,        iommu_pci_attach),
        DEVMETHOD_END
};

DEFINE_CLASS_1(riscv_iommu, riscv_iommu_pci_driver,
    riscv_iommu_pci_methods, sizeof(struct riscv_iommu_softc),
    riscv_iommu_driver);
DRIVER_MODULE(riscv_iommu, pci, riscv_iommu_pci_driver, NULL, NULL);