vfio/mdev: Use struct mdev_type in struct mdev_device

The kobj pointer in mdev_device is actually pointing at a struct
mdev_type. Use the proper type so things are understandable.

There are a number of places that are confused and passing both the mdev
and the mtype as function arguments, fix these to derive the mtype
directly from the mdev to remove the redundancy.
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: <5-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/mdev/mdev_core.c

@@ -73,11 +73,9 @@ static void mdev_put_parent(struct mdev_parent *parent)
 static void mdev_device_remove_common(struct mdev_device *mdev)
 {
 	struct mdev_parent *parent;
-	struct mdev_type *type;
 	int ret;
 
-	type = to_mdev_type(mdev->type_kobj);
-	mdev_remove_sysfs_files(mdev, type);
+	mdev_remove_sysfs_files(mdev);
 	device_del(&mdev->dev);
 	parent = mdev->parent;
 	lockdep_assert_held(&parent->unreg_sem);
@@ -241,13 +239,11 @@ static void mdev_device_release(struct device *dev)
 	mdev_device_free(mdev);
 }
 
-int mdev_device_create(struct kobject *kobj,
-		       struct device *dev, const guid_t *uuid)
+int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
 {
 	int ret;
 	struct mdev_device *mdev, *tmp;
 	struct mdev_parent *parent;
-	struct mdev_type *type = to_mdev_type(kobj);
 
 	parent = mdev_get_parent(type->parent);
 	if (!parent)
@@ -285,14 +281,14 @@ int mdev_device_create(struct kobject *kobj,
 	}
 
 	device_initialize(&mdev->dev);
-	mdev->dev.parent  = dev;
+	mdev->dev.parent = parent->dev;
 	mdev->dev.bus     = &mdev_bus_type;
 	mdev->dev.release = mdev_device_release;
 	dev_set_name(&mdev->dev, "%pUl", uuid);
 	mdev->dev.groups = parent->ops->mdev_attr_groups;
-	mdev->type_kobj = kobj;
+	mdev->type = type;
 
-	ret = parent->ops->create(kobj, mdev);
+	ret = parent->ops->create(&type->kobj, mdev);
 	if (ret)
 		goto ops_create_fail;
 
@@ -300,7 +296,7 @@ int mdev_device_create(struct kobject *kobj,
 	if (ret)
 		goto add_fail;
 
-	ret = mdev_create_sysfs_files(mdev, type);
+	ret = mdev_create_sysfs_files(mdev);
 	if (ret)
 		goto sysfs_fail;
 

drivers/vfio/mdev/mdev_private.h

@@ -40,11 +40,10 @@ struct mdev_type {
 int  parent_create_sysfs_files(struct mdev_parent *parent);
 void parent_remove_sysfs_files(struct mdev_parent *parent);
 
-int  mdev_create_sysfs_files(struct mdev_device *mdev, struct mdev_type *type);
-void mdev_remove_sysfs_files(struct mdev_device *mdev, struct mdev_type *type);
+int  mdev_create_sysfs_files(struct mdev_device *mdev);
+void mdev_remove_sysfs_files(struct mdev_device *mdev);
 
-int  mdev_device_create(struct kobject *kobj,
-			struct device *dev, const guid_t *uuid);
+int mdev_device_create(struct mdev_type *kobj, const guid_t *uuid);
 int  mdev_device_remove(struct mdev_device *dev);
 
 #endif /* MDEV_PRIVATE_H */

drivers/vfio/mdev/mdev_sysfs.c

@@ -67,7 +67,7 @@ static ssize_t create_store(struct kobject *kobj, struct device *dev,
 	if (ret)
 		return ret;
 
-	ret = mdev_device_create(kobj, dev, &uuid);
+	ret = mdev_device_create(to_mdev_type(kobj), &uuid);
 	if (ret)
 		return ret;
 
@@ -249,8 +249,9 @@ static const struct attribute *mdev_device_attrs[] = {
 	NULL,
 };
 
-int mdev_create_sysfs_files(struct mdev_device *mdev, struct mdev_type *type)
+int mdev_create_sysfs_files(struct mdev_device *mdev)
 {
+	struct mdev_type *type = mdev->type;
 	struct kobject *kobj = &mdev->dev.kobj;
 	int ret;
 
@@ -271,15 +272,15 @@ int mdev_create_sysfs_files(struct mdev_device *mdev, struct mdev_type *type)
 create_files_failed:
 	sysfs_remove_link(kobj, "mdev_type");
 type_link_failed:
-	sysfs_remove_link(type->devices_kobj, dev_name(&mdev->dev));
+	sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
 	return ret;
 }
 
-void mdev_remove_sysfs_files(struct mdev_device *mdev, struct mdev_type *type)
+void mdev_remove_sysfs_files(struct mdev_device *mdev)
 {
 	struct kobject *kobj = &mdev->dev.kobj;
 
 	sysfs_remove_files(kobj, mdev_device_attrs);
 	sysfs_remove_link(kobj, "mdev_type");
-	sysfs_remove_link(type->devices_kobj, dev_name(&mdev->dev));
+	sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev));
 }

include/linux/mdev.h

@@ -10,13 +10,15 @@
 #ifndef MDEV_H
 #define MDEV_H
 
+struct mdev_type;
+
 struct mdev_device {
 	struct device dev;
 	struct mdev_parent *parent;
 	guid_t uuid;
 	void *driver_data;
 	struct list_head next;
-	struct kobject *type_kobj;
+	struct mdev_type *type;
 	struct device *iommu_device;
 	bool active;
 };