[PATCH v2 01/10] vfio: ccw: Moving state change out of IRQ context

Pierre Morel
2018-05-25T10:21:09Z

Let's move the state change from the IRQ routine to the
workqueue callback.

Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
---
drivers/s390/cio/vfio_ccw_drv.c | 20 +++++++-------------
drivers/s390/cio/vfio_ccw_fsm.c | 14 ++++++++------
2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index ea6a2d0..57ae1ab 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -70,20 +70,9 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch)
static void vfio_ccw_sch_io_todo(struct work_struct *work)
{
struct vfio_ccw_private *private;
- struct irb *irb;

private = container_of(work, struct vfio_ccw_private, io_work);
- irb = &private->irb;
-
- if (scsw_is_solicited(&irb->scsw)) {
- cp_update_scsw(&private->cp, &irb->scsw);
- cp_free(&private->cp);
- }
- memcpy(private->io_region.irb_area, irb, sizeof(*irb));
-
- if (private->io_trigger)
- eventfd_signal(private->io_trigger, 1);
-
+ vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
if (private->mdev)
private->state = VFIO_CCW_STATE_IDLE;
}
@@ -94,9 +83,14 @@ static void vfio_ccw_sch_io_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 irb *irb = this_cpu_ptr(&cio_irb);

inc_irq_stat(IRQIO_CIO);
- vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
+ memcpy(&private->irb, irb, sizeof(*irb));
+
+ queue_work(vfio_ccw_work_q, &private->io_work);
+ if (private->completion)
+ complete(private->completion);
}

static int vfio_ccw_sch_probe(struct subchannel *sch)
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 3c80064..24e1e04 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -172,14 +172,16 @@ static void fsm_io_request(struct vfio_ccw_private *private,
static void fsm_irq(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
- struct irb *irb = this_cpu_ptr(&cio_irb);
+ struct irb *irb = &private->irb;

- memcpy(&private->irb, irb, sizeof(*irb));
-
- queue_work(vfio_ccw_work_q, &private->io_work);
+ if (scsw_is_solicited(&irb->scsw)) {
+ cp_update_scsw(&private->cp, &irb->scsw);
+ cp_free(&private->cp);
+ }
+ memcpy(private->io_region.irb_area, irb, sizeof(*irb));

- if (private->completion)
- complete(private->completion);
+ if (private->io_trigger)
+ eventfd_signal(private->io_trigger, 1);
}

/*
--
2.7.4