[PATCH v1 15/18] vfio/ccw: Manage private with mdev

[Eric Farman <farman@linux.ibm.com>]

Simplify the lifecycle of a vfio-ccw device by moving the alloc/free
of the vfio-ccw private struct to the mdev probe/remove processing,
rather than the subchannel.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 drivers/s390/cio/vfio_ccw_drv.c     | 35 ++++++++---------------------
 drivers/s390/cio/vfio_ccw_ops.c     | 35 +++++++++++++----------------
 drivers/s390/cio/vfio_ccw_private.h |  5 +++++
 3 files changed, 29 insertions(+), 46 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 6dca35f3ceba..5928460854ec 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -133,7 +133,8 @@ 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 mdev_device *mdev,
+						struct subchannel *sch)
 {
 	struct vfio_ccw_private *private;
 
@@ -141,6 +142,8 @@ static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 	if (!private)
 		return ERR_PTR(-ENOMEM);
 
+	vfio_init_group_dev(&private->vdev, &mdev->dev, &vfio_ccw_dev_ops);
+
 	private->sch = sch;
 	mutex_init(&private->io_mutex);
 	private->state = VFIO_CCW_STATE_STANDBY;
@@ -186,11 +189,12 @@ static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 	kfree(private->cp.guest_cp);
 out_free_private:
 	mutex_destroy(&private->io_mutex);
+	vfio_uninit_group_dev(&private->vdev);
 	kfree(private);
 	return ERR_PTR(-ENOMEM);
 }
 
-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;
 
@@ -205,14 +209,14 @@ static void vfio_ccw_free_private(struct vfio_ccw_private *private)
 	kmem_cache_free(vfio_ccw_io_region, private->io_region);
 	kfree(private->cp.guest_cp);
 	mutex_destroy(&private->io_mutex);
+	vfio_uninit_group_dev(&private->vdev);
 	kfree(private);
 }
 
 static int vfio_ccw_sch_probe(struct subchannel *sch)
 {
 	struct pmcw *pmcw = &sch->schib.pmcw;
-	struct vfio_ccw_private *private;
-	int ret = -ENOMEM;
+	int ret;
 
 	if (pmcw->qf) {
 		dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n",
@@ -220,41 +224,20 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 		return -ENODEV;
 	}
 
-	private = vfio_ccw_alloc_private(sch);
-	if (IS_ERR(private))
-		return PTR_ERR(private);
-
-	dev_set_drvdata(&sch->dev, private);
-
 	ret = mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
 	if (ret)
-		goto out_free;
+		return ret;
 
 	VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n",
 			   sch->schid.cssid, sch->schid.ssid,
 			   sch->schid.sch_no);
 	return 0;
-
-out_free:
-	dev_set_drvdata(&sch->dev, NULL);
-	vfio_ccw_free_private(private);
-	return ret;
 }
 
 static void vfio_ccw_sch_remove(struct subchannel *sch)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
-
-	if (!private)
-		return;
-
-	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
 	mdev_unregister_device(&sch->dev);
 
-	dev_set_drvdata(&sch->dev, NULL);
-
-	vfio_ccw_free_private(private);
-
 	VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
 			   sch->schid.cssid, sch->schid.ssid,
 			   sch->schid.sch_no);
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 60a4855e8ecb..1ce7079c9dbb 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -17,8 +17,6 @@
 
 #include "vfio_ccw_private.h"
 
-static const struct vfio_device_ops vfio_ccw_dev_ops;
-
 static int vfio_ccw_mdev_reset(struct vfio_ccw_private *private)
 {
 	/*
@@ -84,29 +82,28 @@ static struct attribute_group *mdev_type_groups[] = {
 
 static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
+	struct subchannel *sch = to_subchannel(mdev->dev.parent);
+	struct vfio_ccw_private *private;
 	int ret;
 
-	if (private->state == VFIO_CCW_STATE_NOT_OPER)
-		return -ENODEV;
-
-	memset(&private->vdev, 0, sizeof(private->vdev));
-	vfio_init_group_dev(&private->vdev, &mdev->dev,
-			    &vfio_ccw_dev_ops);
+	private = vfio_ccw_alloc_private(mdev, sch);
+	if (IS_ERR(private))
+		return PTR_ERR(private);
 
 	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
-			   private->sch->schid.cssid,
-			   private->sch->schid.ssid,
-			   private->sch->schid.sch_no);
+			   sch->schid.cssid,
+			   sch->schid.ssid,
+			   sch->schid.sch_no);
 
 	ret = vfio_register_emulated_iommu_dev(&private->vdev);
 	if (ret)
-		goto err_init;
+		goto err_alloc;
 	dev_set_drvdata(&mdev->dev, private);
+	dev_set_drvdata(&sch->dev, private);
 	return 0;
 
-err_init:
-	vfio_uninit_group_dev(&private->vdev);
+err_alloc:
+	vfio_ccw_free_private(private);
 	return ret;
 }
 
@@ -122,12 +119,10 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 			   private->sch->schid.ssid,
 			   private->sch->schid.sch_no);
 
+	dev_set_drvdata(&private->sch->dev, NULL);
 	dev_set_drvdata(&mdev->dev, NULL);
 	vfio_unregister_group_dev(&private->vdev);
-
-	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
-
-	vfio_uninit_group_dev(&private->vdev);
+	vfio_ccw_free_private(private);
 }
 
 static int vfio_ccw_mdev_open_device(struct vfio_device *vdev)
@@ -603,7 +598,7 @@ static unsigned int vfio_ccw_get_available(struct mdev_type *mtype)
 	return 1;
 }
 
-static const struct vfio_device_ops vfio_ccw_dev_ops = {
+const struct vfio_device_ops vfio_ccw_dev_ops = {
 	.open_device = vfio_ccw_mdev_open_device,
 	.close_device = vfio_ccw_mdev_close_device,
 	.read = vfio_ccw_mdev_read,
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index e568fd6bcf2a..bf11ebd0d32a 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -117,8 +117,13 @@ struct vfio_ccw_private {
 
 extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
 
+struct vfio_ccw_private *vfio_ccw_alloc_private(struct mdev_device *mdev,
+						struct subchannel *sch);
+void vfio_ccw_free_private(struct vfio_ccw_private *private);
+
 extern struct mdev_driver vfio_ccw_mdev_driver;
 extern const struct mdev_parent_ops vfio_ccw_mdev_ops;
+extern const struct vfio_device_ops vfio_ccw_dev_ops;
 
 /*
  * States of the device statemachine.
-- 
2.32.0