/*-
 * Copyright (c) 2019 Justin Hibbits
 *
 * 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 ``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 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/types.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/endian.h>

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

#include <machine/spr.h>
#include <machine/trap.h>
#include "opal.h"

struct opal_hmi_event {
        uint8_t         version;
        uint8_t         severity;
        uint8_t         type;
        uint8_t         disposition;
        uint8_t         rsvd_1[4];
        uint64_t        hmer;
        uint64_t        tfmr;
        union {
                struct {
                        uint8_t         xstop_type;
                        uint8_t         rsvd_2[3];
                        uint32_t        xstop_reason;
                        union {
                                uint32_t        pir;
                                uint32_t        chip_id;
                        };
                };
        };
};

#define HMI_DISP_RECOVERED      0
#define HMI_DISP_NOT_RECOVERED  1

static void
opal_hmi_event_handler(void *unused, struct opal_msg *msg)
{
        struct opal_hmi_event   evt;

        memcpy(&evt, &msg->params, sizeof(evt));
        printf("Hypervisor Maintenance Event received"
            "(Severity %d, type %d, HMER: %016lx).\n",
            evt.severity, evt.type, evt.hmer);

        if (evt.disposition == HMI_DISP_NOT_RECOVERED)
                panic("Unrecoverable hypervisor maintenance exception on CPU %d",
                    evt.pir);

        return;
}

static int
opal_hmi_handler2(struct trapframe *frame)
{
        /*
         * Use DMAP preallocated pcpu memory to handle
         * the phys flags pointer.
         */
        uint64_t *flags = PCPU_PTR(aim.opal_hmi_flags);
        int err;

        *flags = 0;
        err = opal_call(OPAL_HANDLE_HMI2, DMAP_TO_PHYS((vm_offset_t)flags));

        if (be64toh(*flags) & OPAL_HMI_FLAGS_TOD_TB_FAIL)
                panic("TOD/TB recovery failure");

        if (err == OPAL_SUCCESS)
                return (0);

        printf("HMI handler failed!  OPAL error code: %d\n", err);

        return (-1);
}

static int
opal_hmi_handler(struct trapframe *frame)
{
        int err;

        err = opal_call(OPAL_HANDLE_HMI);

        if (err == OPAL_SUCCESS)
                return (0);

        printf("HMI handler failed!  OPAL error code: %d\n", err);

        return (-1);
}

static void
opal_setup_hmi(void *data)
{
        /* This only works for OPAL, so first make sure we have it. */
        if (opal_check() != 0)
                return;

        if (opal_call(OPAL_CHECK_TOKEN, OPAL_HANDLE_HMI2) == OPAL_TOKEN_PRESENT)
                hmi_handler = opal_hmi_handler2;
        else if (opal_call(OPAL_CHECK_TOKEN, OPAL_HANDLE_HMI) == OPAL_TOKEN_PRESENT)
                hmi_handler = opal_hmi_handler;
        else {
                printf("Warning: No OPAL HMI handler found.\n");
                return;
        }

        EVENTHANDLER_REGISTER(OPAL_HMI_EVT, opal_hmi_event_handler, NULL,
            EVENTHANDLER_PRI_ANY);

        if (bootverbose)
                printf("Installed OPAL HMI handler.\n");
}

SYSINIT(opal_setup_hmi, SI_SUB_CPU, SI_ORDER_ANY, opal_setup_hmi, NULL);