vfio/mdev: Add missing typesafety around mdev_device

The mdev API should accept and pass a 'struct mdev_device *' in all
places, not pass a 'struct device *' and cast it internally with
to_mdev_device(). Particularly in its struct mdev_driver functions, the
whole point of a bus's struct device_driver wrapper is to provide type
safety compared to the default struct device_driver.

Further, the driver core standard is for bus drivers to expose their
device structure in their public headers that can be used with
container_of() inlines and '&foo->dev' to go between the class levels, and
'&foo->dev' to be used with dev_err/etc driver core helper functions. Move
'struct mdev_device' to mdev.h

Once done this allows moving some one instruction exported functions to
static inlines, which in turns allows removing one of the two grotesque
symbol_get()'s related to mdev in the core code.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <3-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 3 insertions, 20 deletions

diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index fdbb3bee99a9..97e2225f7f49 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -24,23 +24,6 @@ struct mdev_parent {
 	struct rw_semaphore unreg_sem;
 };
 
-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 device *iommu_device;
-	bool active;
-};
-
-static inline struct mdev_device *to_mdev_device(struct device *dev)
-{
-	return container_of(dev, struct mdev_device, dev);
-}
-#define dev_is_mdev(d)		((d)->bus == &mdev_bus_type)
-
 struct mdev_type {
 	struct kobject kobj;
 	struct kobject *devices_kobj;
@@ -57,11 +40,11 @@ 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 device *dev, struct mdev_type *type);
-void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type);
+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_device_create(struct kobject *kobj,
 			struct device *dev, const guid_t *uuid);
-int  mdev_device_remove(struct device *dev);
+int  mdev_device_remove(struct mdev_device *dev);
 
 #endif /* MDEV_PRIVATE_H */