vfio: amba: VFIO support for AMBA devices

/*

 * 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;

	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);

#define VFIO_DEVICE_FLAGS_RESET	(1 << 0)	/* Device supports reset */

#define VFIO_DEVICE_FLAGS_PCI	(1 << 1)	/* vfio-pci device */

#define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2)	/* vfio-platform device */

#define VFIO_DEVICE_FLAGS_AMBA  (1 << 3)	/* vfio-amba device */

	__u32	num_regions;	/* Max region index + 1 */

	__u32	num_irqs;	/* Max IRQ index + 1 */

};