[PATCH v3 10/11] vfio/ccw: Refactor vfio_ccw_mdev_reset

Eric Farman
2022-06-30T20:37:10Z

Use both the FSM Close and Open events when resetting an mdev,
rather than making a separate call to cio_enable_subchannel().

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/s390/cio/vfio_ccw_ops.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index fc5b83187bd9..4673b7ddfe20 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -21,25 +21,21 @@ static const struct vfio_device_ops vfio_ccw_dev_ops;

static int vfio_ccw_mdev_reset(struct vfio_ccw_private *private)
{
- struct subchannel *sch;
- int ret;
-
- sch = private->sch;
/*
- * TODO:
- * In the cureent stage, some things like "no I/O running" and "no
- * interrupt pending" are clear, but we are not sure what other state
- * we need to care about.
- * There are still a lot more instructions need to be handled. We
- * should come back here later.
+ * If the FSM state is seen as Not Operational after closing
+ * and re-opening the mdev, return an error.
+ *
+ * Otherwise, change the FSM from STANDBY to IDLE which is
+ * normally done by vfio_ccw_mdev_probe() in current lifecycle.
*/
vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
+ vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_OPEN);
+ if (private->state == VFIO_CCW_STATE_NOT_OPER)
+ return -EINVAL;

- ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
- if (!ret)
- private->state = VFIO_CCW_STATE_IDLE;
+ private->state = VFIO_CCW_STATE_IDLE;

- return ret;
+ return 0;
}

static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
--
2.32.0