[PATCH v2 04/10] vfio: ccw: replace IO_REQ event with SSCH_REQ event

Pierre Morel
2018-05-25T10:21:12Z

The write callback uses the a memory cell of the io_region
as the instruction to proceed.

Since we currently ever used only one instruction, SSCH,
let's state that we can only handle one instruction at a time
- by using a switch/case
- by changing the name of the event to VFIO_CCW_EVENT_SSCH_REQ

Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
---
drivers/s390/cio/vfio_ccw_fsm.c | 67 ++++++++++++-------------------------
drivers/s390/cio/vfio_ccw_ops.c | 16 +++++----
drivers/s390/cio/vfio_ccw_private.h | 2 +-
3 files changed, 31 insertions(+), 54 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 2bc4be66..86dab8c 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -19,14 +19,10 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
union orb *orb;
int ccode;
__u8 lpm;
- unsigned long flags;
int ret;

sch = private->sch;

- spin_lock_irqsave(sch->lock, flags);
- private->state = VFIO_CCW_STATE_BUSY;
-
orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);

/* Issue "Start Subchannel" */
@@ -61,7 +57,6 @@ static int fsm_io_helper(struct vfio_ccw_private *private)
default:
ret = ccode;
}
- spin_unlock_irqrestore(sch->lock, flags);
return ret;
}

@@ -122,50 +117,30 @@ static int fsm_io_request(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
union orb *orb;
- union scsw *scsw = &private->scsw;
struct ccw_io_region *io_region = &private->io_region;
struct mdev_device *mdev = private->mdev;

private->state = VFIO_CCW_STATE_BOXED;

- memcpy(scsw, io_region->scsw_area, sizeof(*scsw));
-
- if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) {
- orb = (union orb *)io_region->orb_area;
-
- /* Don't try to build a cp if transport mode is specified. */
- if (orb->tm.b) {
- io_region->ret_code = -EOPNOTSUPP;
- goto err_out;
- }
- io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
- orb);
- if (io_region->ret_code)
- goto err_out;
-
- io_region->ret_code = cp_prefetch(&private->cp);
- if (io_region->ret_code) {
- cp_free(&private->cp);
- goto err_out;
- }
-
- /* Start channel program and wait for I/O interrupt. */
- io_region->ret_code = fsm_io_helper(private);
- if (io_region->ret_code) {
- cp_free(&private->cp);
- goto err_out;
- }
- return;
- } else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
- /* XXX: Handle halt. */
- io_region->ret_code = -EOPNOTSUPP;
+ orb = (union orb *)io_region->orb_area;
+
+ io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev), orb);
+ if (io_region->ret_code)
goto err_out;
- } else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
- /* XXX: Handle clear. */
- io_region->ret_code = -EOPNOTSUPP;
+
+ io_region->ret_code = cp_prefetch(&private->cp);
+ if (io_region->ret_code) {
+ cp_free(&private->cp);
goto err_out;
}

+ io_region->ret_code = fsm_io_helper(private);
+ if (io_region->ret_code) {
+ cp_free(&private->cp);
+ goto err_out;
+ }
+ return VFIO_CCW_STATE_BUSY;
+
err_out:
return VFIO_CCW_STATE_IDLE;
}
@@ -186,7 +161,7 @@ static int fsm_irq(struct vfio_ccw_private *private,

if (private->io_trigger)
eventfd_signal(private->io_trigger, 1);
- return private->state;
+ return VFIO_CCW_STATE_IDLE;
}

/*
@@ -213,31 +188,31 @@ static int fsm_sch_event(struct vfio_ccw_private *private,
fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
[VFIO_CCW_STATE_NOT_OPER] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_nop,
- [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error,
+ [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq,
[VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_nop,
},
[VFIO_CCW_STATE_STANDBY] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
- [VFIO_CCW_EVENT_IO_REQ] = fsm_io_error,
+ [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_error,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
[VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event,
},
[VFIO_CCW_STATE_IDLE] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
- [VFIO_CCW_EVENT_IO_REQ] = fsm_io_request,
+ [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_request,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
[VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event,
},
[VFIO_CCW_STATE_BOXED] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
- [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
+ [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
[VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event,
},
[VFIO_CCW_STATE_BUSY] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
- [VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
+ [VFIO_CCW_EVENT_SSCH_REQ] = fsm_io_busy,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
[VFIO_CCW_EVENT_SCHIB_CHANGED] = fsm_sch_event,
},
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 41eeb57..0206101 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -188,25 +188,27 @@ static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
{
struct vfio_ccw_private *private;
struct ccw_io_region *region;
+ union scsw *scsw;

if (*ppos + count > sizeof(*region))
return -EINVAL;

private = dev_get_drvdata(mdev_parent_dev(mdev));
- if (private->state != VFIO_CCW_STATE_IDLE)
- return -EACCES;

region = &private->io_region;
if (copy_from_user((void *)region + *ppos, buf, count))
return -EFAULT;

- vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
- if (region->ret_code != 0) {
- private->state = VFIO_CCW_STATE_IDLE;
- return region->ret_code;
+ scsw = (union scsw *) &region->scsw_area;
+ switch (scsw->cmd.fctl) {
+ case SCSW_FCTL_START_FUNC:
+ vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_SSCH_REQ);
+ break;
+ default:
+ return -EOPNOTSUPP;
}

- return count;
+ return region->ret_code ? region->ret_code : count;
}

static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index a2be0c9..94fb408 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -76,7 +76,7 @@ enum vfio_ccw_state {
*/
enum vfio_ccw_event {
VFIO_CCW_EVENT_NOT_OPER,
- VFIO_CCW_EVENT_IO_REQ,
+ VFIO_CCW_EVENT_SSCH_REQ,
VFIO_CCW_EVENT_INTERRUPT,
VFIO_CCW_EVENT_SCHIB_CHANGED,
/* last element! */
--
2.7.4