[RFC PATCH] vfio/ccw: Move mdev stuff out of struct subchannel

[Eric Farman <farman@xxxxxxxxxxxxx>]

Here's my swipe at a cleanup patch that can be folded in
to this series, to get the mdev stuff in a more proper
location for vfio-ccw.

As previously described, the subchannel is a device-agnostic
structure that does/should not need to know about specific
nuances such as mediated devices. This is why things like
struct vfio_ccw_private exist, so move these details there.

Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
---
 drivers/s390/cio/cio.h              |  3 ---
 drivers/s390/cio/vfio_ccw_drv.c     | 13 +++++++------
 drivers/s390/cio/vfio_ccw_private.h |  4 ++++
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 1da45307a186..2ad8833653e9 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -109,9 +109,6 @@ struct subchannel {
 	 * frees it.  Use driver_set_override() to set or clear it.
 	 */
 	const char *driver_override;
-	struct mdev_parent parent;
-	struct mdev_type mdev_type;
-	struct mdev_type *mdev_types[1];
 } __attribute__ ((aligned(8)));
 
 DECLARE_PER_CPU_ALIGNED(struct irb, cio_irb);
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 6605b4239f88..bdf76805d175 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -142,6 +142,10 @@ static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 	INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
 	INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
 
+	private->mdev_type.sysfs_name = "io";
+	private->mdev_type.pretty_name = "I/O subchannel (Non-QDIO)";
+	private->mdev_types[0] = &private->mdev_type;
+
 	private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
 				       GFP_KERNEL);
 	if (!private->cp.guest_cp)
@@ -219,12 +223,9 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 
 	dev_set_drvdata(&sch->dev, private);
 
-	sch->mdev_type.sysfs_name = "io";
-	sch->mdev_type.pretty_name = "I/O subchannel (Non-QDIO)";
-	sch->mdev_types[0] = &sch->mdev_type;
-	ret = mdev_register_parent(&sch->parent, &sch->dev,
+	ret = mdev_register_parent(&private->parent, &sch->dev,
 				   &vfio_ccw_mdev_driver,
-				   sch->mdev_types, 1);
+				   private->mdev_types, 1);
 	if (ret)
 		goto out_free;
 
@@ -244,7 +245,7 @@ static void vfio_ccw_sch_remove(struct subchannel *sch)
 	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
 
 	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
-	mdev_unregister_parent(&sch->parent);
+	mdev_unregister_parent(&private->parent);
 
 	dev_set_drvdata(&sch->dev, NULL);
 
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index 4aa806530974..358996897efc 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -111,6 +111,10 @@ struct vfio_ccw_private {
 	struct eventfd_ctx	*req_trigger;
 	struct work_struct	io_work;
 	struct work_struct	crw_work;
+
+	struct mdev_parent	parent;
+	struct mdev_type	mdev_type;
+	struct mdev_type	*mdev_types[1];
 } __aligned(8);
 
 int vfio_ccw_sch_quiesce(struct subchannel *sch);
-- 
2.31.1