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, 2 insertions, 2 deletions

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 25eb7d5b834b..c43c1dc33333 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -105,8 +105,8 @@ structure to represent a mediated device's driver::
       */
      struct mdev_driver {
 	     const char *name;
-	     int  (*probe)  (struct device *dev);
-	     void (*remove) (struct device *dev);
+	     int  (*probe)  (struct mdev_device *dev);
+	     void (*remove) (struct mdev_device *dev);
 	     struct device_driver    driver;
      };