linux/drivers/vfio/mdev/mdev_driver.c
Jason Gunthorpe 91b9969d9c vfio/mdev: Simplify driver registration
This is only done once, we don't need to generate code to initialize a
structure stored in the ELF .data segment. Fill in the three required
.driver members directly instead of copying data into them during
mdev_register_driver().

Further the to_mdev_driver() function doesn't belong in a public header,
just inline it into the two places that need it. Finally, we can now
clearly see that 'drv' derived from dev->driver cannot be NULL, firstly
because the driver core forbids it, and secondly because NULL won't pass
through the container_of(). Remove the dead code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <4-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-07 15:39:16 -06:00

116 lines
2.3 KiB
C

// 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 =
container_of(dev->driver, struct mdev_driver, driver);
struct mdev_device *mdev = to_mdev_device(dev);
int ret;
ret = mdev_attach_iommu(mdev);
if (ret)
return ret;
if (drv->probe) {
ret = drv->probe(mdev);
if (ret)
mdev_detach_iommu(mdev);
}
return ret;
}
static int mdev_remove(struct device *dev)
{
struct mdev_driver *drv =
container_of(dev->driver, struct mdev_driver, driver);
struct mdev_device *mdev = to_mdev_device(dev);
if (drv->remove)
drv->remove(mdev);
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
*
* Returns a negative value on error, otherwise 0.
**/
int mdev_register_driver(struct mdev_driver *drv)
{
/* initialize common driver fields */
drv->driver.bus = &mdev_bus_type;
/* 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);
}