vfio/mdev: Use vfio_init/register/unregister_group_dev

mdev gets little benefit because it doesn't actually do anything, however
it is the last user, so move the vfio_init/register/unregister_group_dev()
code here for now.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Liu Yi L <yi.l.liu@intel.com>
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: <10-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/mdev/vfio_mdev.c

@@ -124,13 +124,29 @@ static const struct vfio_device_ops vfio_mdev_dev_ops = {
 static int vfio_mdev_probe(struct device *dev)
 {
 	struct mdev_device *mdev = to_mdev_device(dev);
+	struct vfio_device *vdev;
+	int ret;
 
-	return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+
+	vfio_init_group_dev(vdev, &mdev->dev, &vfio_mdev_dev_ops, mdev);
+	ret = vfio_register_group_dev(vdev);
+	if (ret) {
+		kfree(vdev);
+		return ret;
+	}
+	dev_set_drvdata(&mdev->dev, vdev);
+	return 0;
 }
 
 static void vfio_mdev_remove(struct device *dev)
 {
-	vfio_del_group_dev(dev);
+	struct vfio_device *vdev = dev_get_drvdata(dev);
+
+	vfio_unregister_group_dev(vdev);
+	kfree(vdev);
 }
 
 static struct mdev_driver vfio_mdev_driver = {

drivers/vfio/vfio.c

@@ -99,8 +99,8 @@ MODULE_PARM_DESC(enable_unsafe_noiommu_mode, "Enable UNSAFE, no-IOMMU mode.  Thi
 /*
  * vfio_iommu_group_{get,put} are only intended for VFIO bus driver probe
  * and remove functions, any use cases other than acquiring the first
- * reference for the purpose of calling vfio_add_group_dev() or removing
- * that symmetric reference after vfio_del_group_dev() should use the raw
+ * reference for the purpose of calling vfio_register_group_dev() or removing
+ * that symmetric reference after vfio_unregister_group_dev() should use the raw
  * iommu_group_{get,put} functions.  In particular, vfio_iommu_group_put()
  * removes the device from the dummy group and cannot be nested.
  */
@@ -799,29 +799,6 @@ int vfio_register_group_dev(struct vfio_device *device)
 }
 EXPORT_SYMBOL_GPL(vfio_register_group_dev);
 
-int vfio_add_group_dev(struct device *dev, const struct vfio_device_ops *ops,
-		       void *device_data)
-{
-	struct vfio_device *device;
-	int ret;
-
-	device = kzalloc(sizeof(*device), GFP_KERNEL);
-	if (!device)
-		return -ENOMEM;
-
-	vfio_init_group_dev(device, dev, ops, device_data);
-	ret = vfio_register_group_dev(device);
-	if (ret)
-		goto err_kfree;
-	dev_set_drvdata(dev, device);
-	return 0;
-
-err_kfree:
-	kfree(device);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(vfio_add_group_dev);
-
 /**
  * Get a reference to the vfio_device for a device.  Even if the
  * caller thinks they own the device, they could be racing with a
@@ -962,18 +939,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
 }
 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
 
-void *vfio_del_group_dev(struct device *dev)
-{
-	struct vfio_device *device = dev_get_drvdata(dev);
-	void *device_data = device->device_data;
-
-	vfio_unregister_group_dev(device);
-	dev_set_drvdata(dev, NULL);
-	kfree(device);
-	return device_data;
-}
-EXPORT_SYMBOL_GPL(vfio_del_group_dev);
-
 /**
  * VFIO base fd, /dev/vfio/vfio
  */

include/linux/vfio.h

@@ -63,11 +63,6 @@ extern void vfio_iommu_group_put(struct iommu_group *group, struct device *dev);
 void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
 			 const struct vfio_device_ops *ops, void *device_data);
 int vfio_register_group_dev(struct vfio_device *device);
-extern int vfio_add_group_dev(struct device *dev,
-			      const struct vfio_device_ops *ops,
-			      void *device_data);
-
-extern void *vfio_del_group_dev(struct device *dev);
 void vfio_unregister_group_dev(struct vfio_device *device);
 extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
 extern void vfio_device_put(struct vfio_device *device);