/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.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.
 */

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

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include <dev/virtio/virtio.h>
#include <dev/virtio/virtio_config.h>
#include <dev/virtio/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_RPMSG,              "Remote Processor Messaging"    },
        { VIRTIO_ID_SCSI,               "SCSI"                          },
        { VIRTIO_ID_9P,                 "9P Transport"                  },
        { VIRTIO_ID_RPROC_SERIAL,       "Remote Processor Serial"       },
        { VIRTIO_ID_CAIF,               "CAIF"                          },
        { VIRTIO_ID_GPU,                "GPU"                           },
        { VIRTIO_ID_INPUT,              "Input"                         },
        { VIRTIO_ID_VSOCK,              "VSOCK Transport"               },
        { VIRTIO_ID_CRYPTO,             "Crypto"                        },
        { VIRTIO_ID_IOMMU,              "IOMMU"                         },
        { VIRTIO_ID_SOUND,              "Sound"                         },
        { VIRTIO_ID_FS,                 "Filesystem"                    },
        { VIRTIO_ID_PMEM,               "Persistent Memory"             },
        { VIRTIO_ID_RPMB,               "RPMB"                          },
        { VIRTIO_ID_SCMI,               "SCMI"                          },
        { VIRTIO_ID_GPIO,               "GPIO"                          },

        { 0, NULL }
};

/* Device independent features. */
static struct virtio_feature_desc virtio_common_feature_desc[] = {
        { VIRTIO_F_NOTIFY_ON_EMPTY,     "NotifyOnEmpty"         }, /* Legacy */
        { VIRTIO_F_ANY_LAYOUT,          "AnyLayout"             }, /* Legacy */
        { VIRTIO_RING_F_INDIRECT_DESC,  "RingIndirectDesc"      },
        { VIRTIO_RING_F_EVENT_IDX,      "RingEventIdx"          },
        { VIRTIO_F_BAD_FEATURE,         "BadFeature"            }, /* Legacy */
        { VIRTIO_F_VERSION_1,           "Version1"              },
        { VIRTIO_F_IOMMU_PLATFORM,      "IOMMUPlatform"         },
        { VIRTIO_F_RING_PACKED,         "RingPacked"            },
        { VIRTIO_F_IN_ORDER,            "InOrder"               },
        { VIRTIO_F_ORDER_PLATFORM,      "OrderPlatform"         },
        { VIRTIO_F_SR_IOV,              "SRIOV"                 },
        { VIRTIO_F_NOTIFICATION_DATA,   "NotificationData"      },
        { VIRTIO_F_NOTIF_CONFIG_DATA,   "NotifConfigData"       },
        { VIRTIO_F_RING_RESET,          "RingReset"             },
        { VIRTIO_F_ADMIN_VQ,            "AdminVq"               },

        { 0, NULL }
};

SYSCTL_NODE(_hw, OID_AUTO, virtio, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "VirtIO driver parameters");

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);
}

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);
}

int
virtio_describe_sbuf(struct sbuf *sb, uint64_t features,
    struct virtio_feature_desc *desc)
{
        const char *name;
        uint64_t val;
        int n;

        sbuf_printf(sb, "%#jx", (uintmax_t) 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, ">");

        return (sbuf_finish(sb));
}

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

        if ((buf = malloc(1024, M_TEMP, M_NOWAIT)) == NULL) {
                error = ENOMEM;
                goto out;
        }

        sbuf_new(&sb, buf, 1024, SBUF_FIXEDLEN);
        sbuf_printf(&sb, "%s features: ", msg);

        error = virtio_describe_sbuf(&sb, features, desc);
        if (error == 0)
                device_printf(dev, "%s\n", sbuf_data(&sb));

        sbuf_delete(&sb);
        free(buf, M_TEMP);

out:
        if (error != 0) {
                device_printf(dev, "%s features: %#jx\n", msg,
                    (uintmax_t) features);
        }
}

uint64_t
virtio_filter_transport_features(uint64_t features)
{
        uint64_t transport, mask;

        transport = (1ULL <<
            (VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START)) - 1;
        transport <<= VIRTIO_TRANSPORT_F_START;

        mask = -1ULL & ~transport;
        mask |= VIRTIO_RING_F_INDIRECT_DESC;
        mask |= VIRTIO_RING_F_EVENT_IDX;
        mask |= VIRTIO_F_VERSION_1;

        return (features & mask);
}

bool
virtio_bus_is_modern(device_t dev)
{
        uintptr_t modern;

        virtio_read_ivar(dev, VIRTIO_IVAR_MODERN, &modern);
        return (modern != 0);
}

void
virtio_read_device_config_array(device_t dev, bus_size_t offset, void *dst,
    int size, int count)
{
        int i, gen;

        do {
                gen = virtio_config_generation(dev);

                for (i = 0; i < count; i++) {
                        virtio_read_device_config(dev, offset + i * size,
                            (uint8_t *) dst + i * size, size);
                }
        } while (gen != virtio_config_generation(dev));
}

/*
 * VirtIO bus method wrappers.
 */

void
virtio_read_ivar(device_t dev, int ivar, uintptr_t *val)
{

        *val = -1;
        BUS_READ_IVAR(device_get_parent(dev), dev, ivar, val);
}

void
virtio_write_ivar(device_t dev, int ivar, uintptr_t val)
{

        BUS_WRITE_IVAR(device_get_parent(dev), dev, ivar, val);
}

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_finalize_features(device_t dev)
{

        return (VIRTIO_BUS_FINALIZE_FEATURES(device_get_parent(dev)));
}

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, enum intr_type type)
{

        return (VIRTIO_BUS_SETUP_INTR(device_get_parent(dev), type));
}

bool
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));
}

int
virtio_config_generation(device_t dev)
{

        return (VIRTIO_BUS_CONFIG_GENERATION(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, const void *dst, int len)
{

        VIRTIO_BUS_WRITE_DEVICE_CONFIG(device_get_parent(dev),
            offset, dst, len);
}

int
virtio_child_pnpinfo(device_t busdev __unused, device_t child, struct sbuf *sb)
{

        /*
         * All of these PCI fields will be only 16 bits, but on the vtmmio bus
         * the corresponding fields (only "vendor" and "device_type") are 32
         * bits.  Many virtio drivers can attach below either bus.
         * Gratuitously expand these two fields to 32-bits to allow sharing PNP
         * match table data between the mostly-similar buses.
         *
         * Subdevice and device_type are redundant in both buses, so I don't
         * see a lot of PNP utility in exposing the same value under a
         * different name.
         */
        sbuf_printf(sb, "vendor=0x%08x device=0x%04x subvendor=0x%04x "
            "device_type=0x%08x", (unsigned)virtio_get_vendor(child),
            (unsigned)virtio_get_device(child),
            (unsigned)virtio_get_subvendor(child),
            (unsigned)virtio_get_device_type(child));
        return (0);
}

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

        switch (type) {
        case MOD_LOAD:
        case MOD_QUIESCE:
        case MOD_UNLOAD:
        case MOD_SHUTDOWN:
                error = 0;
                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_FIRST);
MODULE_VERSION(virtio, 1);