freebsd-skq/sys/dev/virtio/virtio.h
bryanv 263105576c Add VirtIO bus config_generation method
VirtIO buses (PCI, MMIO) can provide a generation field so a driver
can ensure either a 64-bit or array read was stable.

MFC after:	2 weeks
2018-02-19 19:28:24 +00:00

148 lines
4.9 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2014, 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_H_
#define _VIRTIO_H_
#include <dev/virtio/virtio_ids.h>
#include <dev/virtio/virtio_config.h>
struct vq_alloc_info;
/*
* Each virtqueue indirect descriptor list must be physically contiguous.
* To allow us to malloc(9) each list individually, limit the number
* supported to what will fit in one page. With 4KB pages, this is a limit
* of 256 descriptors. If there is ever a need for more, we can switch to
* contigmalloc(9) for the larger allocations, similar to what
* bus_dmamem_alloc(9) does.
*
* Note the sizeof(struct vring_desc) is 16 bytes.
*/
#define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
/*
* VirtIO instance variables indices.
*/
#define VIRTIO_IVAR_DEVTYPE 1
#define VIRTIO_IVAR_FEATURE_DESC 2
#define VIRTIO_IVAR_VENDOR 3
#define VIRTIO_IVAR_DEVICE 4
#define VIRTIO_IVAR_SUBVENDOR 5
#define VIRTIO_IVAR_SUBDEVICE 6
struct virtio_feature_desc {
uint64_t vfd_val;
const char *vfd_str;
};
const char *virtio_device_name(uint16_t devid);
void virtio_describe(device_t dev, const char *msg,
uint64_t features, struct virtio_feature_desc *feature_desc);
/*
* VirtIO Bus Methods.
*/
void virtio_read_ivar(device_t dev, int ivar, uintptr_t *val);
void virtio_write_ivar(device_t dev, int ivar, uintptr_t val);
uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
int virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
struct vq_alloc_info *info);
int virtio_setup_intr(device_t dev, enum intr_type type);
int virtio_with_feature(device_t dev, uint64_t feature);
void virtio_stop(device_t dev);
int virtio_config_generation(device_t dev);
int virtio_reinit(device_t dev, uint64_t features);
void virtio_reinit_complete(device_t dev);
/*
* Read/write a variable amount from the device specific (ie, network)
* configuration region. This region is encoded in the same endian as
* the guest.
*/
void virtio_read_device_config(device_t dev, bus_size_t offset,
void *dst, int length);
void virtio_write_device_config(device_t dev, bus_size_t offset,
void *src, int length);
/* Inlined device specific read/write functions for common lengths. */
#define VIRTIO_RDWR_DEVICE_CONFIG(size, type) \
static inline type \
__CONCAT(virtio_read_dev_config_,size)(device_t dev, \
bus_size_t offset) \
{ \
type val; \
virtio_read_device_config(dev, offset, &val, sizeof(type)); \
return (val); \
} \
\
static inline void \
__CONCAT(virtio_write_dev_config_,size)(device_t dev, \
bus_size_t offset, type val) \
{ \
virtio_write_device_config(dev, offset, &val, sizeof(type)); \
}
VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
#undef VIRTIO_RDWR_DEVICE_CONFIG
#define VIRTIO_READ_IVAR(name, ivar) \
static inline int \
__CONCAT(virtio_get_,name)(device_t dev) \
{ \
uintptr_t val; \
virtio_read_ivar(dev, ivar, &val); \
return ((int) val); \
}
VIRTIO_READ_IVAR(device_type, VIRTIO_IVAR_DEVTYPE);
VIRTIO_READ_IVAR(vendor, VIRTIO_IVAR_VENDOR);
VIRTIO_READ_IVAR(device, VIRTIO_IVAR_DEVICE);
VIRTIO_READ_IVAR(subvendor, VIRTIO_IVAR_SUBVENDOR);
VIRTIO_READ_IVAR(subdevice, VIRTIO_IVAR_SUBDEVICE);
#undef VIRTIO_READ_IVAR
#define VIRTIO_WRITE_IVAR(name, ivar) \
static inline void \
__CONCAT(virtio_set_,name)(device_t dev, void *val) \
{ \
virtio_write_ivar(dev, ivar, (uintptr_t) val); \
}
VIRTIO_WRITE_IVAR(feature_desc, VIRTIO_IVAR_FEATURE_DESC);
#undef VIRTIO_WRITE_IVAR
#endif /* _VIRTIO_H_ */