vfio/platform: initial skeleton of VFIO support for platform devices

This patch forms the common skeleton code for platform devices support
with VFIO. This will include the core functionality of VFIO_PLATFORM,
however binding to the device and discovering the device resources will
be done with the help of a separate file where any Linux platform bus
specific code will reside.

This will allow us to implement support for also discovering AMBA devices
and their resources, but still reuse a large part of the VFIO_PLATFORM
implementation.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
[Baptiste Reynal: added includes in vfio_platform_private.h]
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Antonios Motakis 2015-03-16 14:08:42 -06:00 committed by Alex Williamson
parent 06e5801b8c
commit de49fc0d99
2 changed files with 160 additions and 0 deletions

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/*
* Copyright (C) 2013 - Virtual Open Systems
* Author: Antonios Motakis <a.motakis@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vfio.h>
#include "vfio_platform_private.h"
static void vfio_platform_release(void *device_data)
{
module_put(THIS_MODULE);
}
static int vfio_platform_open(void *device_data)
{
if (!try_module_get(THIS_MODULE))
return -ENODEV;
return 0;
}
static long vfio_platform_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
if (cmd == VFIO_DEVICE_GET_INFO)
return -EINVAL;
else if (cmd == VFIO_DEVICE_GET_REGION_INFO)
return -EINVAL;
else if (cmd == VFIO_DEVICE_GET_IRQ_INFO)
return -EINVAL;
else if (cmd == VFIO_DEVICE_SET_IRQS)
return -EINVAL;
else if (cmd == VFIO_DEVICE_RESET)
return -EINVAL;
return -ENOTTY;
}
static ssize_t vfio_platform_read(void *device_data, char __user *buf,
size_t count, loff_t *ppos)
{
return -EINVAL;
}
static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
size_t count, loff_t *ppos)
{
return -EINVAL;
}
static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
{
return -EINVAL;
}
static const struct vfio_device_ops vfio_platform_ops = {
.name = "vfio-platform",
.open = vfio_platform_open,
.release = vfio_platform_release,
.ioctl = vfio_platform_ioctl,
.read = vfio_platform_read,
.write = vfio_platform_write,
.mmap = vfio_platform_mmap,
};
int vfio_platform_probe_common(struct vfio_platform_device *vdev,
struct device *dev)
{
struct iommu_group *group;
int ret;
if (!vdev)
return -EINVAL;
group = iommu_group_get(dev);
if (!group) {
pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
return -EINVAL;
}
ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
if (ret) {
iommu_group_put(group);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
{
struct vfio_platform_device *vdev;
vdev = vfio_del_group_dev(dev);
if (vdev)
iommu_group_put(dev->iommu_group);
return vdev;
}
EXPORT_SYMBOL_GPL(vfio_platform_remove_common);

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/*
* Copyright (C) 2013 - Virtual Open Systems
* Author: Antonios Motakis <a.motakis@virtualopensystems.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef VFIO_PLATFORM_PRIVATE_H
#define VFIO_PLATFORM_PRIVATE_H
#include <linux/types.h>
#include <linux/interrupt.h>
struct vfio_platform_device {
/*
* These fields should be filled by the bus specific binder
*/
void *opaque;
const char *name;
uint32_t flags;
/* callbacks to discover device resources */
struct resource*
(*get_resource)(struct vfio_platform_device *vdev, int i);
int (*get_irq)(struct vfio_platform_device *vdev, int i);
};
extern int vfio_platform_probe_common(struct vfio_platform_device *vdev,
struct device *dev);
extern struct vfio_platform_device *vfio_platform_remove_common
(struct device *dev);
#endif /* VFIO_PLATFORM_PRIVATE_H */