vfio/mdev: embedd struct mdev_parent in the parent data structure

Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure.  This
removes the need for a list of parents and the separate mdev_parent
refcount as we can simplify rely on the reference to the parent device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index f47dca6645aa..cd1667608ab5 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -58,19 +58,19 @@ devices as examples, as these devices are the first devices to use this module::
      |  MDEV CORE    |
      |   MODULE      |
      |   mdev.ko     |
-     | +-----------+ |  mdev_register_device() +--------------+
+     | +-----------+ |  mdev_register_parent() +--------------+
      | |           | +<------------------------+              |
      | |           | |                         |  nvidia.ko   |<-> physical
      | |           | +------------------------>+              |    device
      | |           | |        callbacks        +--------------+
      | | Physical  | |
-     | |  device   | |  mdev_register_device() +--------------+
+     | |  device   | |  mdev_register_parent() +--------------+
      | | interface | |<------------------------+              |
      | |           | |                         |  i915.ko     |<-> physical
      | |           | +------------------------>+              |    device
      | |           | |        callbacks        +--------------+
      | |           | |
-     | |           | |  mdev_register_device() +--------------+
+     | |           | |  mdev_register_parent() +--------------+
      | |           | +<------------------------+              |
      | |           | |                         | ccw_device.ko|<-> physical
      | |           | +------------------------>+              |    device
@@ -125,8 +125,8 @@ vfio_device_ops.
 When a driver wants to add the GUID creation sysfs to an existing device it has
 probe'd to then it should call::
 
-    int mdev_register_device(struct device *dev,
-                             struct mdev_driver *mdev_driver);
+    int mdev_register_parent(struct mdev_parent *parent, struct device *dev,
+			struct mdev_driver *mdev_driver);
 
 This will provide the 'mdev_supported_types/XX/create' files which can then be
 used to trigger the creation of a mdev_device. The created mdev_device will be
@@ -134,7 +134,7 @@ attached to the specified driver.
 
 When the driver needs to remove itself it calls::
 
-    void mdev_unregister_device(struct device *dev);
+    void mdev_unregister_parent(struct mdev_parent *parent);
 
 Which will unbind and destroy all the created mdevs and remove the sysfs files.