[PATCH v1 4/7] vfio/ccw: move private to mdev lifecycle

[Eric Farman]

Now that the mdev parent data is split out into its own struct,
it is safe to move the remaining private data to follow the
mdev probe/remove lifecycle. The mdev parent data will remain
where it is, and follow the subchannel and the css driver
interfaces.

Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
---
 drivers/s390/cio/vfio_ccw_drv.c     | 17 ++---------------
 drivers/s390/cio/vfio_ccw_ops.c     | 26 +++++++++++++-------------
 drivers/s390/cio/vfio_ccw_private.h |  3 +++
 3 files changed, 18 insertions(+), 28 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index cc9ed2fd970f..686a9b9f6731 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -146,7 +146,7 @@ static void vfio_ccw_sch_irq(struct subchannel *sch)
 	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
 }
 
-static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
+struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 {
 	struct vfio_ccw_private *private;
 
@@ -157,7 +157,7 @@ static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 	return private;
 }
 
-static void vfio_ccw_free_private(struct vfio_ccw_private *private)
+void vfio_ccw_free_private(struct vfio_ccw_private *private)
 {
 	struct vfio_ccw_crw *crw, *temp;
 
@@ -185,7 +185,6 @@ static void vfio_ccw_free_parent(struct device *dev)
 static int vfio_ccw_sch_probe(struct subchannel *sch)
 {
 	struct pmcw *pmcw = &sch->schib.pmcw;
-	struct vfio_ccw_private *private;
 	struct vfio_ccw_parent *parent;
 	int ret = -ENOMEM;
 
@@ -202,14 +201,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	parent->dev.release = &vfio_ccw_free_parent;
 	device_initialize(&parent->dev);
 
-	private = vfio_ccw_alloc_private(sch);
-	if (IS_ERR(private)) {
-		put_device(&parent->dev);
-		return PTR_ERR(private);
-	}
-
 	dev_set_drvdata(&sch->dev, parent);
-	dev_set_drvdata(&parent->dev, private);
 
 	parent->mdev_type.sysfs_name = "io";
 	parent->mdev_type.pretty_name = "I/O subchannel (Non-QDIO)";
@@ -226,9 +218,7 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	return 0;
 
 out_free:
-	dev_set_drvdata(&parent->dev, NULL);
 	dev_set_drvdata(&sch->dev, NULL);
-	vfio_ccw_free_private(private);
 	put_device(&parent->dev);
 	return ret;
 }
@@ -236,13 +226,10 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 static void vfio_ccw_sch_remove(struct subchannel *sch)
 {
 	struct vfio_ccw_parent *parent = dev_get_drvdata(&sch->dev);
-	struct vfio_ccw_private *private = dev_get_drvdata(&parent->dev);
 
 	mdev_unregister_parent(&parent->parent);
 
 	dev_set_drvdata(&sch->dev, NULL);
-
-	vfio_ccw_free_private(private);
 	put_device(&parent->dev);
 
 	VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 626b8eb3507b..3e627b236241 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -101,15 +101,20 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 {
 	struct subchannel *sch = to_subchannel(mdev->dev.parent);
 	struct vfio_ccw_parent *parent = dev_get_drvdata(&sch->dev);
-	struct vfio_ccw_private *private = dev_get_drvdata(&parent->dev);
+	struct vfio_ccw_private *private;
 	int ret;
 
-	if (private->state == VFIO_CCW_STATE_NOT_OPER)
-		return -ENODEV;
+	private = vfio_ccw_alloc_private(sch);
+	if (!private)
+		return -ENOMEM;
 
 	ret = vfio_init_device(&private->vdev, &mdev->dev, &vfio_ccw_dev_ops);
-	if (ret)
+	if (ret) {
+		kfree(private);
 		return ret;
+	}
+
+	dev_set_drvdata(&parent->dev, private);
 
 	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
 			   sch->schid.cssid,
@@ -123,6 +128,7 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 	return 0;
 
 err_put_vdev:
+	dev_set_drvdata(&parent->dev, NULL);
 	vfio_put_device(&private->vdev);
 	return ret;
 }
@@ -132,15 +138,6 @@ static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
 	struct vfio_ccw_private *private =
 		container_of(vdev, struct vfio_ccw_private, vdev);
 
-	/*
-	 * We cannot free vfio_ccw_private here because it includes
-	 * parent info which must be free'ed by css driver.
-	 *
-	 * Use a workaround by memset'ing the core device part and
-	 * then notifying the remove path that all active references
-	 * to this device have been released.
-	 */
-	memset(vdev, 0, sizeof(*vdev));
 	complete(&private->release_comp);
 }
 
@@ -157,6 +154,7 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 
 	vfio_unregister_group_dev(&private->vdev);
 
+	dev_set_drvdata(&parent->dev, NULL);
 	vfio_put_device(&private->vdev);
 	/*
 	 * Wait for all active references on mdev are released so it
@@ -167,6 +165,8 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 	 * cycle.
 	 */
 	wait_for_completion(&private->release_comp);
+
+	vfio_ccw_free_private(private);
 }
 
 static int vfio_ccw_mdev_open_device(struct vfio_device *vdev)
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index b35940057073..c1959b8bfe86 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -119,6 +119,9 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch);
 void vfio_ccw_sch_io_todo(struct work_struct *work);
 void vfio_ccw_crw_todo(struct work_struct *work);
 
+struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch);
+void vfio_ccw_free_private(struct vfio_ccw_private *private);
+
 extern struct mdev_driver vfio_ccw_mdev_driver;
 
 /*
-- 
2.34.1