alistair23-linux/drivers/vfio/platform/vfio_amba.c
Sinan Kaya b5add544d6 vfio, platform: make reset driver a requirement by default
The code was allowing platform devices to be used without a supporting
VFIO reset driver. The hardware can be left in some inconsistent state
after a guest machine abort.

The reset driver will put the hardware back to safe state and disable
interrupts before returning the control back to the host machine.

Adding a new reset_required kernel module option to platform VFIO drivers.
The default value is true for the DT and ACPI based drivers.
The reset requirement value for AMBA drivers is set to false and is
unchangeable to maintain the existing functionality.

New requirements are:
1. A reset function needs to be implemented by the corresponding driver
via DT/ACPI.
2. The reset function needs to be discovered via DT/ACPI.

The probe of the driver will fail if any of the above conditions are
not satisfied.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:46 -06:00

118 lines
2.7 KiB
C

/*
* 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/module.h>
#include <linux/slab.h>
#include <linux/vfio.h>
#include <linux/amba/bus.h>
#include "vfio_platform_private.h"
#define DRIVER_VERSION "0.10"
#define DRIVER_AUTHOR "Antonios Motakis <a.motakis@virtualopensystems.com>"
#define DRIVER_DESC "VFIO for AMBA devices - User Level meta-driver"
/* probing devices from the AMBA bus */
static struct resource *get_amba_resource(struct vfio_platform_device *vdev,
int i)
{
struct amba_device *adev = (struct amba_device *) vdev->opaque;
if (i == 0)
return &adev->res;
return NULL;
}
static int get_amba_irq(struct vfio_platform_device *vdev, int i)
{
struct amba_device *adev = (struct amba_device *) vdev->opaque;
int ret = 0;
if (i < AMBA_NR_IRQS)
ret = adev->irq[i];
/* zero is an unset IRQ for AMBA devices */
return ret ? ret : -ENXIO;
}
static int vfio_amba_probe(struct amba_device *adev, const struct amba_id *id)
{
struct vfio_platform_device *vdev;
int ret;
vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
if (!vdev)
return -ENOMEM;
vdev->name = kasprintf(GFP_KERNEL, "vfio-amba-%08x", adev->periphid);
if (!vdev->name) {
kfree(vdev);
return -ENOMEM;
}
vdev->opaque = (void *) adev;
vdev->flags = VFIO_DEVICE_FLAGS_AMBA;
vdev->get_resource = get_amba_resource;
vdev->get_irq = get_amba_irq;
vdev->parent_module = THIS_MODULE;
vdev->reset_required = false;
ret = vfio_platform_probe_common(vdev, &adev->dev);
if (ret) {
kfree(vdev->name);
kfree(vdev);
}
return ret;
}
static int vfio_amba_remove(struct amba_device *adev)
{
struct vfio_platform_device *vdev;
vdev = vfio_platform_remove_common(&adev->dev);
if (vdev) {
kfree(vdev->name);
kfree(vdev);
return 0;
}
return -EINVAL;
}
static struct amba_id pl330_ids[] = {
{ 0, 0 },
};
MODULE_DEVICE_TABLE(amba, pl330_ids);
static struct amba_driver vfio_amba_driver = {
.probe = vfio_amba_probe,
.remove = vfio_amba_remove,
.id_table = pl330_ids,
.drv = {
.name = "vfio-amba",
.owner = THIS_MODULE,
},
};
module_amba_driver(vfio_amba_driver);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);