vfio/ccw: Create an OPEN FSM Event

Move the process of enabling a subchannel for use by vfio-ccw
into the FSM, such that it can manage the sequence of lifecycle
events for the device.

That is, if the FSM state is NOT_OPER(erational), then do the work
that would enable the subchannel and move the FSM to STANDBY state.
An attempt to perform this event again from any of the other operating
states (IDLE, CP_PROCESSING, CP_PENDING) will convert the device back
to NOT_OPER so the configuration process can be started again.

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/20220707135737.720765-9-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index fe87a26..7d91896 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -231,15 +231,10 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 
        dev_set_drvdata(&sch->dev, private);
 
-       spin_lock_irq(sch->lock);
-       sch->isc = VFIO_CCW_ISC;
-       ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
-       spin_unlock_irq(sch->lock);
-       if (ret)
+       vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_OPEN);
+       if (private->state == VFIO_CCW_STATE_NOT_OPER)
                goto out_free;
 
-       private->state = VFIO_CCW_STATE_STANDBY;
-
        ret = mdev_register_device(&sch->dev, &vfio_ccw_mdev_driver);
        if (ret)
                goto out_disable;

diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 88e529a..2811b20 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -11,6 +11,8 @@
 
 #include <linux/vfio.h>
 
+#include <asm/isc.h>
+
 #include "ioasm.h"
 #include "vfio_ccw_private.h"
 
@@ -368,6 +370,20 @@ static void fsm_irq(struct vfio_ccw_private *private,
                complete(private->completion);
 }
 
+static void fsm_open(struct vfio_ccw_private *private,
+                    enum vfio_ccw_event event)
+{
+       struct subchannel *sch = private->sch;
+       int ret;
+
+       spin_lock_irq(sch->lock);
+       sch->isc = VFIO_CCW_ISC;
+       ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
+       if (!ret)
+               private->state = VFIO_CCW_STATE_STANDBY;
+       spin_unlock_irq(sch->lock);
+}
+
 /*
  * Device statemachine
  */
@@ -377,29 +393,34 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
                [VFIO_CCW_EVENT_IO_REQ]         = fsm_io_error,
                [VFIO_CCW_EVENT_ASYNC_REQ]      = fsm_async_error,
                [VFIO_CCW_EVENT_INTERRUPT]      = fsm_disabled_irq,
+               [VFIO_CCW_EVENT_OPEN]           = fsm_open,
        },
        [VFIO_CCW_STATE_STANDBY] = {
                [VFIO_CCW_EVENT_NOT_OPER]       = fsm_notoper,
                [VFIO_CCW_EVENT_IO_REQ]         = fsm_io_error,
                [VFIO_CCW_EVENT_ASYNC_REQ]      = fsm_async_error,
                [VFIO_CCW_EVENT_INTERRUPT]      = fsm_irq,
+               [VFIO_CCW_EVENT_OPEN]           = fsm_notoper,
        },
        [VFIO_CCW_STATE_IDLE] = {
                [VFIO_CCW_EVENT_NOT_OPER]       = fsm_notoper,
                [VFIO_CCW_EVENT_IO_REQ]         = fsm_io_request,
                [VFIO_CCW_EVENT_ASYNC_REQ]      = fsm_async_request,
                [VFIO_CCW_EVENT_INTERRUPT]      = fsm_irq,
+               [VFIO_CCW_EVENT_OPEN]           = fsm_notoper,
        },
        [VFIO_CCW_STATE_CP_PROCESSING] = {
                [VFIO_CCW_EVENT_NOT_OPER]       = fsm_notoper,
                [VFIO_CCW_EVENT_IO_REQ]         = fsm_io_retry,
                [VFIO_CCW_EVENT_ASYNC_REQ]      = fsm_async_retry,
                [VFIO_CCW_EVENT_INTERRUPT]      = fsm_irq,
+               [VFIO_CCW_EVENT_OPEN]           = fsm_notoper,
        },
        [VFIO_CCW_STATE_CP_PENDING] = {
                [VFIO_CCW_EVENT_NOT_OPER]       = fsm_notoper,
                [VFIO_CCW_EVENT_IO_REQ]         = fsm_io_busy,
                [VFIO_CCW_EVENT_ASYNC_REQ]      = fsm_async_request,
                [VFIO_CCW_EVENT_INTERRUPT]      = fsm_irq,
+               [VFIO_CCW_EVENT_OPEN]           = fsm_notoper,
        },
 };

diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index a2584c1..93e136b 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -142,6 +142,7 @@ enum vfio_ccw_event {
        VFIO_CCW_EVENT_IO_REQ,
        VFIO_CCW_EVENT_INTERRUPT,
        VFIO_CCW_EVENT_ASYNC_REQ,
+       VFIO_CCW_EVENT_OPEN,
        /* last element! */
        NR_VFIO_CCW_EVENTS
 };