/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2020 Val Packett <val@packett.cool>
 * Copyright (c) 2021 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/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>

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

#include "acpi_bus_if.h"
#include "pmu.h"

struct madt_ctx {
        struct pmu_softc *sc;
        int error;
        int i;
};

static void
madt_handler(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        ACPI_MADT_GENERIC_INTERRUPT *intr;
        struct intr_map_data_acpi *ad;
        struct intr_map_data *data;
        struct madt_ctx *ctx;
        struct pmu_softc *sc;
        struct pcpu *pcpu;
        int rid;
        int cpuid;
        int i;

        ctx = arg;
        sc = ctx->sc;
        rid = ctx->i;
        cpuid = -1;

        if (ctx->error)
                return;

        if (entry->Type != ACPI_MADT_TYPE_GENERIC_INTERRUPT)
                return;
        intr = (ACPI_MADT_GENERIC_INTERRUPT *)entry;

        for (i = 0; i < MAXCPU; i++) {
                pcpu = pcpu_find(i);
                if (pcpu != NULL && PCPU_GET_MPIDR(pcpu) == intr->ArmMpidr) {
                        cpuid = i;
                        break;
                }
        }

        if (cpuid == -1) {
                /* pcpu not found. */
                device_printf(sc->dev, "MADT: could not find pcpu, "
                    "ArmMpidr %lx\n", intr->ArmMpidr);
                return;
        }

        if (bootverbose)
                device_printf(sc->dev, "MADT: cpu %d (mpidr %lu) irq %d "
                    "%s-triggered\n", cpuid, intr->ArmMpidr,
                    intr->PerformanceInterrupt,
                    (intr->Flags & ACPI_MADT_PERFORMANCE_IRQ_MODE) ?
                    "edge" : "level");

        bus_set_resource(sc->dev, SYS_RES_IRQ, ctx->i,
            intr->PerformanceInterrupt, 1);

        sc->irq[ctx->i].res = bus_alloc_resource_any(sc->dev, SYS_RES_IRQ,
            &rid, RF_ACTIVE | RF_SHAREABLE);
        if (sc->irq[ctx->i].res == NULL) {
                device_printf(sc->dev, "Failed to allocate IRQ %d\n", ctx->i);
                ctx->error = ENXIO;
                return;
        }

        /*
         * BUS_CONFIG_INTR does nothing on arm64, so we manually set trigger
         * mode.
         */
        data = rman_get_virtual(sc->irq[ctx->i].res);
        KASSERT(data->type == INTR_MAP_DATA_ACPI, ("Wrong data type"));
        ad = (struct intr_map_data_acpi *)data;
        ad->trig = (intr->Flags & ACPI_MADT_PERFORMANCE_IRQ_MODE) ?
                INTR_TRIGGER_EDGE : INTR_TRIGGER_LEVEL;
        ad->pol = INTR_POLARITY_HIGH;

        if (!intr_is_per_cpu(sc->irq[ctx->i].res))
                sc->irq[ctx->i].cpuid = cpuid;

        ctx->i++;
}

static void
pmu_acpi_identify(driver_t *driver, device_t parent)
{
        device_t dev;

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

        dev = BUS_ADD_CHILD(parent, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LAST,
            "pmu", -1);

        if (dev == NULL)
                device_printf(parent, "pmu: Unable to add pmu child\n");
}

static int
pmu_acpi_probe(device_t dev)
{

        device_set_desc(dev, "Performance Monitoring Unit");

        return (BUS_PROBE_NOWILDCARD);
}

static int
pmu_acpi_attach(device_t dev)
{
        struct pmu_softc *sc;
        struct madt_ctx ctx;
        ACPI_TABLE_MADT *madt;
        int i;

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

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

        /* We have to initialize cpuid to -1. */
        for (i = 0; i < MAX_RLEN; i++)
                sc->irq[i].cpuid = -1;

        ctx.sc = sc;
        ctx.i = 0;
        ctx.error = 0;
        acpi_walk_subtables(madt + 1, (char *)madt + madt->Header.Length,
            madt_handler, &ctx);

        acpi_unmap_table(madt);

        if (ctx.error)
                return (ctx.error);

        return (pmu_attach(dev));
}

static device_method_t pmu_acpi_methods[] = {
        DEVMETHOD(device_identify,      pmu_acpi_identify),
        DEVMETHOD(device_probe,         pmu_acpi_probe),
        DEVMETHOD(device_attach,        pmu_acpi_attach),
        DEVMETHOD_END,
};

DEFINE_CLASS_0(pmu, pmu_acpi_driver, pmu_acpi_methods,
    sizeof(struct pmu_softc));

DRIVER_MODULE(pmu, acpi, pmu_acpi_driver, 0, 0);