[PATCH v1 16/18] vfio/ccw: Create a get_private routine

[Eric Farman <farman@xxxxxxxxxxxxx>]

Refactor out the logic of getting the vfio_ccw_private struct from
the subchannel, so that it can be synchronized with vfio better.

Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
---
 drivers/s390/cio/vfio_ccw_drv.c     | 10 +++++-----
 drivers/s390/cio/vfio_ccw_private.h | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 5928460854ec..c8cbbad6e1c5 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -37,7 +37,7 @@ debug_info_t *vfio_ccw_debug_trace_id;
  */
 int vfio_ccw_sch_quiesce(struct subchannel *sch)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
+	struct vfio_ccw_private *private = vfio_ccw_get_private(sch);
 	DECLARE_COMPLETION_ONSTACK(completion);
 	int iretry, ret = 0;
 
@@ -124,7 +124,7 @@ static void vfio_ccw_crw_todo(struct work_struct *work)
  */
 static void vfio_ccw_sch_irq(struct subchannel *sch)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
+	struct vfio_ccw_private *private = vfio_ccw_get_private(sch);
 
 	if (WARN_ON(!private))
 		return;
@@ -245,7 +245,7 @@ static void vfio_ccw_sch_remove(struct subchannel *sch)
 
 static void vfio_ccw_sch_shutdown(struct subchannel *sch)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
+	struct vfio_ccw_private *private = vfio_ccw_get_private(sch);
 
 	if (!private)
 		return;
@@ -266,7 +266,7 @@ static void vfio_ccw_sch_shutdown(struct subchannel *sch)
  */
 static int vfio_ccw_sch_event(struct subchannel *sch, int process)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
+	struct vfio_ccw_private *private = vfio_ccw_get_private(sch);
 	unsigned long flags;
 	int rc = -EAGAIN;
 
@@ -321,7 +321,7 @@ static void vfio_ccw_queue_crw(struct vfio_ccw_private *private,
 static int vfio_ccw_chp_event(struct subchannel *sch,
 			      struct chp_link *link, int event)
 {
-	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
+	struct vfio_ccw_private *private = vfio_ccw_get_private(sch);
 	int mask = chp_ssd_get_mask(&sch->ssd_info, link);
 	int retry = 255;
 
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index bf11ebd0d32a..3833204bd388 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -24,6 +24,8 @@
 #include "css.h"
 #include "vfio_ccw_cp.h"
 
+struct mdev_device;
+
 #define VFIO_CCW_OFFSET_SHIFT   10
 #define VFIO_CCW_OFFSET_TO_INDEX(off)	(off >> VFIO_CCW_OFFSET_SHIFT)
 #define VFIO_CCW_INDEX_TO_OFFSET(index)	((u64)(index) << VFIO_CCW_OFFSET_SHIFT)
@@ -125,6 +127,18 @@ 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;
 
+static inline struct vfio_ccw_private *vfio_ccw_get_private(struct subchannel *sch)
+{
+	struct vfio_ccw_private *private;
+
+	if (!sch)
+		return NULL;
+
+	private = dev_get_drvdata(&sch->dev);
+
+	return private;
+}
+
 /*
  * States of the device statemachine.
  */
-- 
2.32.0