freebsd-skq/sys/dev/virtio/virtio_endian.h
Bryan Venteicher 9da9560c4d virtio: Add VirtIO PCI modern (V1) support
Use the existing legacy PCI driver as the basis for shared code
between the legacy and modern PCI drivers. The existing virtio_pci
kernel module will contain both the legacy and modern drivers.

Changes to the virtqueue and each device driver (network, block, etc)
for V1 support come in later commits.

Update the MMIO driver to reflect the VirtIO bus method changes, but
the modern compliance can be improved on later.

Note that the modern PCI driver requires bus_map_resource() to be
implemented, which is not the case on all archs.

The hw.virtio.pci.transitional tunable default value is zero so
transitional devices will continue to be driven via the legacy
driver.

Reviewed by: grehan (mentor)
Differential Revision: https://reviews.freebsd.org/D27856
2021-01-19 04:55:23 +00:00

107 lines
2.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2017, 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.
*
* $FreeBSD$
*/
#ifndef _VIRTIO_ENDIAN_H_
#define _VIRTIO_ENDIAN_H_
#include <sys/endian.h>
/*
* VirtIO V1 (modern) uses little endian, while legacy VirtIO uses the guest's
* native endian. These functions convert to and from the Guest's (driver's)
* and the Host's (device's) endianness when needed.
*/
static inline bool
virtio_swap_endian(bool modern)
{
#if _BYTE_ORDER == _LITTLE_ENDIAN
return (false);
#else
return (modern);
#endif
}
static inline uint16_t
virtio_htog16(bool modern, uint16_t val)
{
if (virtio_swap_endian(modern))
return (le16toh(val));
else
return (val);
}
static inline uint16_t
virtio_gtoh16(bool modern, uint16_t val)
{
if (virtio_swap_endian(modern))
return (htole16(val));
else
return (val);
}
static inline uint32_t
virtio_htog32(bool modern, uint32_t val)
{
if (virtio_swap_endian(modern))
return (le32toh(val));
else
return (val);
}
static inline uint32_t
virtio_gtoh32(bool modern, uint32_t val)
{
if (virtio_swap_endian(modern))
return (htole32(val));
else
return (val);
}
static inline uint64_t
virtio_htog64(bool modern, uint64_t val)
{
if (virtio_swap_endian(modern))
return (le64toh(val));
else
return (val);
}
static inline uint64_t
virtio_gtoh64(bool modern, uint64_t val)
{
if (virtio_swap_endian(modern))
return (htole64(val));
else
return (val);
}
#endif /* _VIRTIO_ENDIAN_H_ */