freebsd-dev/sys/dev/virtio/virtio.c

/*-
 * 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/cdefs.h>
__FBSDID("$FreeBSD$");

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

#include <dev/virtio/virtio.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_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_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);
}

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);
}

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 = malloc(512, M_TEMP, M_NOWAIT)) == NULL) {
		device_printf(dev, "%s features: %#jx\n", msg, (uintmax_t) features);
		return;
	}

	sbuf_new(&sb, buf, 512, SBUF_FIXEDLEN);
	sbuf_printf(&sb, "%s features: %#jx", msg, (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, ">");

#if __FreeBSD_version < 900020
	sbuf_finish(&sb);
	if (sbuf_overflowed(&sb) == 0)
#else
	if (sbuf_finish(&sb) == 0)
#endif
		device_printf(dev, "%s\n", sbuf_data(&sb));

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

/*
 * 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_alloc_virtqueues(device_t dev, int flags, int nvqs,
    struct vq_alloc_info *info)
{

	return (VIRTIO_BUS_ALLOC_VIRTQUEUES(device_get_parent(dev), flags,
	    nvqs, info));
}

int
virtio_setup_intr(device_t dev, enum intr_type type)
{

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

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;

	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);