[PATCH v2 7/9] vfio/ccw: Remove private->mdev

[Jason Gunthorpe <jgg@nvidia.com>]

Having a mdev pointer floating about in addition to a struct vfio_device
is confusing. It is only used for three things:

- Getting the mdev 'struct device *' - this is the same as
     private->vdev.dev

- Printing the uuid of the mdev in logging. The uuid is also the dev_name
  of the mdev so this is the same string as
     dev_name(private->vdev.dev)

- A weird attempt to fence the vfio_ccw_sch_io_todo() work. This work is
  only queued during states IDLE/PROCESSING/PENDING and flushed when
  entering CLOSED. Thus the work already cannot run when the mdev is NULL.
  Remove it.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/s390/cio/vfio_ccw_drv.c     |  6 ++--
 drivers/s390/cio/vfio_ccw_fsm.c     | 48 +++++++++++++----------------
 drivers/s390/cio/vfio_ccw_ops.c     | 16 ++++------
 drivers/s390/cio/vfio_ccw_private.h |  2 --
 include/linux/mdev.h                |  4 ---
 5 files changed, 30 insertions(+), 46 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index de782e967a5474..0e2edd96567a09 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -64,7 +64,7 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work)
 	 * has finished. Do not overwrite a possible processing
 	 * state if the final interrupt was for HSCH or CSCH.
 	 */
-	if (private->mdev && cp_is_finished)
+	if (cp_is_finished)
 		private->state = VFIO_CCW_STATE_IDLE;
 
 	if (private->io_trigger)
@@ -303,8 +303,8 @@ static int vfio_ccw_chp_event(struct subchannel *sch,
 		return 0;
 
 	trace_vfio_ccw_chp_event(private->sch->schid, mask, event);
-	VFIO_CCW_MSG_EVENT(2, "%pUl (%x.%x.%04x): mask=0x%x event=%d\n",
-			   mdev_uuid(private->mdev), sch->schid.cssid,
+	VFIO_CCW_MSG_EVENT(2, "%s (%x.%x.%04x): mask=0x%x event=%d\n",
+			   dev_name(private->vdev.dev), sch->schid.cssid,
 			   sch->schid.ssid, sch->schid.sch_no,
 			   mask, event);
 
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 302215090b9ac7..df1490943b20ec 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -245,7 +245,6 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 	union orb *orb;
 	union scsw *scsw = &private->scsw;
 	struct ccw_io_region *io_region = private->io_region;
-	struct mdev_device *mdev = private->mdev;
 	char *errstr = "request";
 	struct subchannel_id schid = get_schid(private);
 
@@ -258,32 +257,30 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 		/* Don't try to build a cp if transport mode is specified. */
 		if (orb->tm.b) {
 			io_region->ret_code = -EOPNOTSUPP;
-			VFIO_CCW_MSG_EVENT(2,
-					   "%pUl (%x.%x.%04x): transport mode\n",
-					   mdev_uuid(mdev), schid.cssid,
-					   schid.ssid, schid.sch_no);
+			VFIO_CCW_MSG_EVENT(
+				2, "%s (%x.%x.%04x): transport mode\n",
+				dev_name(private->vdev.dev), schid.cssid,
+				schid.ssid, schid.sch_no);
 			errstr = "transport mode";
 			goto err_out;
 		}
-		io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
+		io_region->ret_code = cp_init(&private->cp, private->vdev.dev,
 					      orb);
 		if (io_region->ret_code) {
-			VFIO_CCW_MSG_EVENT(2,
-					   "%pUl (%x.%x.%04x): cp_init=%d\n",
-					   mdev_uuid(mdev), schid.cssid,
-					   schid.ssid, schid.sch_no,
-					   io_region->ret_code);
+			VFIO_CCW_MSG_EVENT(2, "%s (%x.%x.%04x): cp_init=%d\n",
+					   dev_name(private->vdev.dev),
+					   schid.cssid, schid.ssid,
+					   schid.sch_no, io_region->ret_code);
 			errstr = "cp init";
 			goto err_out;
 		}
 
 		io_region->ret_code = cp_prefetch(&private->cp);
 		if (io_region->ret_code) {
-			VFIO_CCW_MSG_EVENT(2,
-					   "%pUl (%x.%x.%04x): cp_prefetch=%d\n",
-					   mdev_uuid(mdev), schid.cssid,
-					   schid.ssid, schid.sch_no,
-					   io_region->ret_code);
+			VFIO_CCW_MSG_EVENT(
+				2, "%s (%x.%x.%04x): cp_prefetch=%d\n",
+				dev_name(private->vdev.dev), schid.cssid,
+				schid.ssid, schid.sch_no, io_region->ret_code);
 			errstr = "cp prefetch";
 			cp_free(&private->cp);
 			goto err_out;
@@ -292,28 +289,25 @@ static void fsm_io_request(struct vfio_ccw_private *private,
 		/* Start channel program and wait for I/O interrupt. */
 		io_region->ret_code = fsm_io_helper(private);
 		if (io_region->ret_code) {
-			VFIO_CCW_MSG_EVENT(2,
-					   "%pUl (%x.%x.%04x): fsm_io_helper=%d\n",
-					   mdev_uuid(mdev), schid.cssid,
-					   schid.ssid, schid.sch_no,
-					   io_region->ret_code);
+			VFIO_CCW_MSG_EVENT(
+				2, "%s (%x.%x.%04x): fsm_io_helper=%d\n",
+				dev_name(private->vdev.dev), schid.cssid,
+				schid.ssid, schid.sch_no, io_region->ret_code);
 			errstr = "cp fsm_io_helper";
 			cp_free(&private->cp);
 			goto err_out;
 		}
 		return;
 	} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
-		VFIO_CCW_MSG_EVENT(2,
-				   "%pUl (%x.%x.%04x): halt on io_region\n",
-				   mdev_uuid(mdev), schid.cssid,
+		VFIO_CCW_MSG_EVENT(2, "%s (%x.%x.%04x): halt on io_region\n",
+				   dev_name(private->vdev.dev), schid.cssid,
 				   schid.ssid, schid.sch_no);
 		/* halt is handled via the async cmd region */
 		io_region->ret_code = -EOPNOTSUPP;
 		goto err_out;
 	} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
-		VFIO_CCW_MSG_EVENT(2,
-				   "%pUl (%x.%x.%04x): clear on io_region\n",
-				   mdev_uuid(mdev), schid.cssid,
+		VFIO_CCW_MSG_EVENT(2, "%s (%x.%x.%04x): clear on io_region\n",
+				   dev_name(private->vdev.dev), schid.cssid,
 				   schid.ssid, schid.sch_no);
 		/* clear is handled via the async cmd region */
 		io_region->ret_code = -EOPNOTSUPP;
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 38ab5c1f25ec09..23004e67c492f6 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -95,11 +95,9 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 	vfio_init_group_dev(&private->vdev, &mdev->dev,
 			    &vfio_ccw_dev_ops);
 
-	private->mdev = mdev;
-
-	VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: create\n",
-			   mdev_uuid(mdev), private->sch->schid.cssid,
-			   private->sch->schid.ssid,
+	VFIO_CCW_MSG_EVENT(2, "mdev %s, sch %x.%x.%04x: create\n",
+			   dev_name(private->vdev.dev),
+			   private->sch->schid.cssid, private->sch->schid.ssid,
 			   private->sch->schid.sch_no);
 
 	ret = vfio_register_group_dev(&private->vdev);
@@ -110,7 +108,6 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 
 err_init:
 	vfio_uninit_group_dev(&private->vdev);
-	private->mdev = NULL;
 	return ret;
 }
 
@@ -118,14 +115,13 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
 
-	VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: remove\n",
-			   mdev_uuid(mdev), private->sch->schid.cssid,
-			   private->sch->schid.ssid,
+	VFIO_CCW_MSG_EVENT(2, "mdev %s, sch %x.%x.%04x: remove\n",
+			   dev_name(private->vdev.dev),
+			   private->sch->schid.cssid, private->sch->schid.ssid,
 			   private->sch->schid.sch_no);
 
 	vfio_unregister_group_dev(&private->vdev);
 	vfio_uninit_group_dev(&private->vdev);
-	private->mdev = NULL;
 }
 
 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 bbc97eb9d9c6fc..67ee9c624393b0 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -72,7 +72,6 @@ struct vfio_ccw_crw {
  * @sch: pointer to the subchannel
  * @state: internal state of the device
  * @completion: synchronization helper of the I/O completion
- * @mdev: pointer to the mediated device
  * @nb: notifier for vfio events
  * @io_region: MMIO region to input/output I/O arguments/results
  * @io_mutex: protect against concurrent update of I/O regions
@@ -95,7 +94,6 @@ struct vfio_ccw_private {
 	struct subchannel	*sch;
 	int			state;
 	struct completion	*completion;
-	struct mdev_device	*mdev;
 	struct notifier_block	nb;
 	struct ccw_io_region	*io_region;
 	struct mutex		io_mutex;
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 819eaf98ffac73..ea59610d45fd89 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -158,10 +158,6 @@ static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
 {
 	mdev->driver_data = data;
 }
-static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
-{
-	return &mdev->uuid;
-}
 
 extern struct bus_type mdev_bus_type;
 
-- 
2.33.0