/*-
 * Copyright (c) 2011, Bryan Venteicher <bryanv@daemoninthecloset.org>
 * All rights reserved.
 *
 * 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 unmodified, 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.
 *
 * $FreeBSD: src/sys/dev/virtio/virtio.c,v 1.1 2011/11/18 05:43:43 grehan Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sbuf.h>

#include <machine/inttypes.h>
#include <sys/bus.h>
#include <sys/serialize.h>
#include <sys/rman.h>

#include "virtio.h"
#include "virtqueue.h"

#include "virtio_bus_if.h"

static int virtio_modevent(module_t, int, void *);
static const char *virtio_feature_name(uint64_t, struct virtio_feature_desc *);

static struct virtio_ident {
        uint16_t devid;
        const char *name;
} virtio_ident_table[] = {
        { VIRTIO_ID_NETWORK,    "Network"       },
        { VIRTIO_ID_BLOCK,      "Block"         },
        { VIRTIO_ID_CONSOLE,    "Console"       },
        { VIRTIO_ID_ENTROPY,    "Entropy"       },
        { VIRTIO_ID_BALLOON,    "Balloon"       },
        { VIRTIO_ID_IOMEMORY,   "IOMemory"      },
        { VIRTIO_ID_SCSI,       "SCSI"          },
        { VIRTIO_ID_9P,         "9P Transport"  },

        { 0, NULL }
};

/* Device independent features. */
static struct virtio_feature_desc virtio_common_feature_desc[] = {
        { VIRTIO_F_NOTIFY_ON_EMPTY,     "NotifyOnEmpty" },
        { VIRTIO_F_ANY_LAYOUT,          "AnyLayout"     },
        { VIRTIO_RING_F_INDIRECT_DESC,  "RingIndirect"  },
        { VIRTIO_RING_F_EVENT_IDX,      "EventIdx"      },
        { VIRTIO_F_BAD_FEATURE,         "BadFeature"    },

        { 0, NULL }
};

const char *
virtio_device_name(uint16_t devid)
{
        struct virtio_ident *ident;

        for (ident = virtio_ident_table; ident->name != NULL; ident++) {
                if (ident->devid == devid)
                        return (ident->name);
        }

        return (NULL);
}

int
virtio_get_device_type(device_t dev)
{
        uintptr_t devtype;

        devtype = -1;

        BUS_READ_IVAR(device_get_parent(dev), dev,
            VIRTIO_IVAR_DEVTYPE, &devtype);

        return ((int) devtype);
}

void
virtio_set_feature_desc(device_t dev,
    struct virtio_feature_desc *feature_desc)
{

        BUS_WRITE_IVAR(device_get_parent(dev), dev,
            VIRTIO_IVAR_FEATURE_DESC, (uintptr_t) feature_desc);
}

void
virtio_describe(device_t dev, const char *msg,
    uint64_t features, struct virtio_feature_desc *desc)
{
        struct sbuf sb;
        uint64_t val;
        char *buf;
        const char *name;
        int n;

        if ((buf = kmalloc(512, M_TEMP, M_INTWAIT)) == NULL) {
                device_printf(dev, "%s features: 0x%"PRIx64"\n", msg,
                    features);
                return;
        }

        sbuf_new(&sb, buf, 512, SBUF_FIXEDLEN);
        sbuf_printf(&sb, "%s features: 0x%"PRIx64, msg, features);

        for (n = 0, val = 1ULL << 63; val != 0; val >>= 1) {
                /*
                 * BAD_FEATURE is used to detect broken Linux clients
                 * and therefore is not applicable to FreeBSD.
                 */
                if (((features & val) == 0) || val == VIRTIO_F_BAD_FEATURE)
                        continue;

                if (n++ == 0)
                        sbuf_cat(&sb, " <");
                else
                        sbuf_cat(&sb, ",");

                name = virtio_feature_name(val, desc);
                if (name == NULL)
                        sbuf_printf(&sb, "%#jx", (uintmax_t) val);
                else
                        sbuf_cat(&sb, name);
        }

        if (n > 0)
                sbuf_cat(&sb, ">");

        if (sbuf_finish(&sb) == 0)
                device_printf(dev, "%s\n", sbuf_data(&sb));

        sbuf_delete(&sb);
        kfree(buf, M_TEMP);
}

static const char *
virtio_feature_name(uint64_t val, struct virtio_feature_desc *desc)
{
        int i, j;
        struct virtio_feature_desc *descs[2] = { desc,
            virtio_common_feature_desc };

        for (i = 0; i < 2; i++) {
                if (descs[i] == NULL)
                        continue;

                for (j = 0; descs[i][j].vfd_val != 0; j++) {
                        if (val == descs[i][j].vfd_val)
                                return (descs[i][j].vfd_str);
                }
        }

        return (NULL);
}

/*
 * VirtIO bus method wrappers.
 */

uint64_t
virtio_negotiate_features(device_t dev, uint64_t child_features)
{
        return (VIRTIO_BUS_NEGOTIATE_FEATURES(device_get_parent(dev),
                child_features));
}

int
virtio_alloc_virtqueues(device_t dev, int nvqs, struct vq_alloc_info *info)
{
        return (VIRTIO_BUS_ALLOC_VIRTQUEUES(device_get_parent(dev),
                nvqs, info));
}

int
virtio_setup_intr(device_t dev, uint irq, lwkt_serialize_t slz)
{
        return (VIRTIO_BUS_SETUP_INTR(device_get_parent(dev), irq, slz));
}

int
virtio_teardown_intr(device_t dev, uint irq)
{
        return (VIRTIO_BUS_TEARDOWN_INTR(device_get_parent(dev), irq));
}

int
virtio_intr_count(device_t dev)
{
        return (VIRTIO_BUS_INTR_COUNT(device_get_parent(dev)));
}

int
virtio_intr_alloc(device_t dev, int *cnt, int use_config, int *cpus)
{
        return (VIRTIO_BUS_INTR_ALLOC(device_get_parent(dev), cnt, use_config,
                                      cpus));
}

int
virtio_intr_release(device_t dev)
{
        return (VIRTIO_BUS_INTR_RELEASE(device_get_parent(dev)));
}

int
virtio_bind_intr(device_t dev, uint irq, int what,
    driver_intr_t handler, void *arg)
{
        return (VIRTIO_BUS_BIND_INTR(device_get_parent(dev), irq, what,
                                     handler, arg));
}

int
virtio_unbind_intr(device_t dev, int what)
{
        return (VIRTIO_BUS_UNBIND_INTR(device_get_parent(dev), what));
}

int
virtio_with_feature(device_t dev, uint64_t feature)
{
        return (VIRTIO_BUS_WITH_FEATURE(device_get_parent(dev), feature));
}

void
virtio_stop(device_t dev)
{
        VIRTIO_BUS_STOP(device_get_parent(dev));
}

int
virtio_reinit(device_t dev, uint64_t features)
{
        return (VIRTIO_BUS_REINIT(device_get_parent(dev), features));
}

void
virtio_reinit_complete(device_t dev)
{
        VIRTIO_BUS_REINIT_COMPLETE(device_get_parent(dev));
}

void
virtio_read_device_config(device_t dev, bus_size_t offset, void *dst, int len)
{
        VIRTIO_BUS_READ_DEVICE_CONFIG(device_get_parent(dev),
                                      offset, dst, len);
}

void
virtio_write_device_config(device_t dev, bus_size_t offset, void *dst, int len)
{
        VIRTIO_BUS_WRITE_DEVICE_CONFIG(device_get_parent(dev),
                                       offset, dst, len);
}

static int
virtio_modevent(module_t mod, int type, void *unused)
{
        int error;

        error = 0;

        switch (type) {
        case MOD_LOAD:
        case MOD_UNLOAD:
        case MOD_SHUTDOWN:
                break;
        default:
                error = EOPNOTSUPP;
                break;
        }

        return (error);
}

static moduledata_t virtio_mod = {
        "virtio",
        virtio_modevent,
        0
};

DECLARE_MODULE(virtio, virtio_mod, SI_SUB_DRIVERS, SI_ORDER_EARLIER);
MODULE_VERSION(virtio, 1);