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

From: Eric Farman
Date: Wed Oct 19 2022 - 12:22:27 EST


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