mdev_driver.c
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// SPDX-License-Identifier: GPL-2.0-only
/*
* MDEV driver
*
* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
* Author: Neo Jia <cjia@nvidia.com>
* Kirti Wankhede <kwankhede@nvidia.com>
*/
#include <linux/device.h>
#include <linux/iommu.h>
#include <linux/mdev.h>
#include "mdev_private.h"
static int mdev_attach_iommu(struct mdev_device *mdev)
{
int ret;
struct iommu_group *group;
group = iommu_group_alloc();
if (IS_ERR(group))
return PTR_ERR(group);
ret = iommu_group_add_device(group, &mdev->dev);
if (!ret)
dev_info(&mdev->dev, "MDEV: group_id = %d\n",
iommu_group_id(group));
iommu_group_put(group);
return ret;
}
static void mdev_detach_iommu(struct mdev_device *mdev)
{
iommu_group_remove_device(&mdev->dev);
dev_info(&mdev->dev, "MDEV: detaching iommu\n");
}
static int mdev_probe(struct device *dev)
{
struct mdev_driver *drv = to_mdev_driver(dev->driver);
struct mdev_device *mdev = to_mdev_device(dev);
int ret;
ret = mdev_attach_iommu(mdev);
if (ret)
return ret;
if (drv && drv->probe) {
ret = drv->probe(dev);
if (ret)
mdev_detach_iommu(mdev);
}
return ret;
}
static int mdev_remove(struct device *dev)
{
struct mdev_driver *drv = to_mdev_driver(dev->driver);
struct mdev_device *mdev = to_mdev_device(dev);
if (drv && drv->remove)
drv->remove(dev);
mdev_detach_iommu(mdev);
return 0;
}
struct bus_type mdev_bus_type = {
.name = "mdev",
.probe = mdev_probe,
.remove = mdev_remove,
};
EXPORT_SYMBOL_GPL(mdev_bus_type);
/**
* mdev_register_driver - register a new MDEV driver
* @drv: the driver to register
* @owner: module owner of driver to be registered
*
* Returns a negative value on error, otherwise 0.
**/
int mdev_register_driver(struct mdev_driver *drv, struct module *owner)
{
/* initialize common driver fields */
drv->driver.name = drv->name;
drv->driver.bus = &mdev_bus_type;
drv->driver.owner = owner;
/* register with core */
return driver_register(&drv->driver);
}
EXPORT_SYMBOL(mdev_register_driver);
/*
* mdev_unregister_driver - unregister MDEV driver
* @drv: the driver to unregister
*/
void mdev_unregister_driver(struct mdev_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(mdev_unregister_driver);
int mdev_bus_register(void)
{
return bus_register(&mdev_bus_type);
}
void mdev_bus_unregister(void)
{
bus_unregister(&mdev_bus_type);
}