diff options
| author | Eric Farman <farman@linux.ibm.com> | 2022-07-07 15:57:37 +0200 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2022-07-07 14:06:12 -0600 |
| commit | 204b394a23ad5e30944f23518e21e844614da2ff (patch) | |
| tree | b606c730cd50da310253376c0d4db5f42e1e388e /drivers/s390/cio/vfio_ccw_drv.c | |
| parent | bfec266c8159450720705f16208736e03812e5dc (diff) | |
vfio/ccw: Move FSM open/close to MDEV open/close
Part of the confusion that has existed is the FSM lifecycle of
subchannels between the common CSS driver and the vfio-ccw driver.
During configuration, the FSM state goes from NOT_OPER to STANDBY
to IDLE, but then back to NOT_OPER. For example:
vfio_ccw_sch_probe: VFIO_CCW_STATE_NOT_OPER
vfio_ccw_sch_probe: VFIO_CCW_STATE_STANDBY
vfio_ccw_mdev_probe: VFIO_CCW_STATE_IDLE
vfio_ccw_mdev_remove: VFIO_CCW_STATE_NOT_OPER
vfio_ccw_sch_remove: VFIO_CCW_STATE_NOT_OPER
vfio_ccw_sch_shutdown: VFIO_CCW_STATE_NOT_OPER
Rearrange the open/close events to align with the mdev open/close,
to better manage the memory and state of the devices as time
progresses. Specifically, make mdev_open() perform the FSM open,
and mdev_close() perform the FSM close instead of reset (which is
both close and open).
This makes the NOT_OPER state a dead-end path, indicating the
device is probably not recoverable without fully probing and
re-configuring the device.
This has the nice side-effect of removing a number of special-cases
where the FSM state is managed outside of the FSM itself (such as
the aforementioned mdev_close() routine).
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-12-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_drv.c')
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_drv.c | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index f98c9915e73d..4804101ccb0f 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -138,7 +138,7 @@ static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch) private->sch = sch; mutex_init(&private->io_mutex); - private->state = VFIO_CCW_STATE_NOT_OPER; + private->state = VFIO_CCW_STATE_STANDBY; INIT_LIST_HEAD(&private->crw); INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo); INIT_WORK(&private->crw_work, vfio_ccw_crw_todo); @@ -222,21 +222,15 @@ static int vfio_ccw_sch_probe(struct subchannel *sch) dev_set_drvdata(&sch->dev, private); - vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_OPEN); - if (private->state == VFIO_CCW_STATE_NOT_OPER) - goto out_free; - ret = mdev_register_device(&sch->dev, &vfio_ccw_mdev_driver); if (ret) - goto out_disable; + goto out_free; 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_disable: - cio_disable_subchannel(sch); out_free: dev_set_drvdata(&sch->dev, NULL); vfio_ccw_free_private(private); @@ -264,6 +258,7 @@ static void vfio_ccw_sch_shutdown(struct subchannel *sch) struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE); + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); } /** |