Re: [PATCH v2 08/10] vfio/ccw: Create a CLOSE FSM event

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 6/15/22 4:33 PM, Eric Farman wrote:
Refactor the vfio_ccw_sch_quiesce() routine to extract the bit that
disables the subchannel and affects the FSM state. Use this to form
the basis of a CLOSE event that will mirror the OPEN event, and move
the subchannel back to NOT_OPER state.

Similar comments here related to previous patch. If a close event can trigger fsm_notoper then it should probably should cut a different trace entry when event == CLOSE


A key difference with that mirroring is that while OPEN handles the
transition from NOT_OPER => STANDBY, the later probing of the mdev
handles the transition from STANDBY => IDLE. On the other hand,
the CLOSE event will move from one of the operating states {IDLE,
CP_PROCESSING, CP_PENDING} => NOT_OPER. That is, there is no stop
in a STANDBY state on the deconfigure path.

Add a call to cp_free() in this event, such that it is captured for
the various permutations of this event.

In the unlikely event that cio_disable_subchannel() returns -EBUSY,
the remaining logic of vfio_ccw_sch_quiesce() can still be used.

Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
---
  drivers/s390/cio/vfio_ccw_drv.c     | 17 +++++------------
  drivers/s390/cio/vfio_ccw_fsm.c     | 26 ++++++++++++++++++++++++++
  drivers/s390/cio/vfio_ccw_ops.c     | 14 ++------------
  drivers/s390/cio/vfio_ccw_private.h |  1 +
  4 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 52249c40a565..62bd6f969b76 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -41,13 +41,6 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch)
  	DECLARE_COMPLETION_ONSTACK(completion);
  	int iretry, ret = 0;
- spin_lock_irq(sch->lock);
-	if (!sch->schib.pmcw.ena)
-		goto out_unlock;
-	ret = cio_disable_subchannel(sch);
-	if (ret != -EBUSY)
-		goto out_unlock;
-
  	iretry = 255;
  	do {
@@ -74,9 +67,7 @@ int vfio_ccw_sch_quiesce(struct subchannel *sch)
  		spin_lock_irq(sch->lock);
  		ret = cio_disable_subchannel(sch);
  	} while (ret == -EBUSY);
-out_unlock:
-	private->state = VFIO_CCW_STATE_NOT_OPER;
-	spin_unlock_irq(sch->lock);
+
  	return ret;
  }
@@ -258,7 +249,7 @@ static void vfio_ccw_sch_remove(struct subchannel *sch)
  {
  	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
- vfio_ccw_sch_quiesce(sch);
+	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
  	mdev_unregister_device(&sch->dev);
dev_set_drvdata(&sch->dev, NULL);
@@ -272,7 +263,9 @@ static void vfio_ccw_sch_remove(struct subchannel *sch)
static void vfio_ccw_sch_shutdown(struct subchannel *sch)
  {
-	vfio_ccw_sch_quiesce(sch);
+	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
+
+	vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
  }
/**
diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 7e7ed69e1461..fa546d33e595 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -380,6 +380,27 @@ static void fsm_open(struct vfio_ccw_private *private,
  	spin_unlock_irq(sch->lock);
  }
+static void fsm_close(struct vfio_ccw_private *private,
+		      enum vfio_ccw_event event)
+{
+	struct subchannel *sch = private->sch;
+	int ret;
+
+	spin_lock_irq(sch->lock);
+
+	if (!sch->schib.pmcw.ena)
+		goto out_unlock;
+
+	ret = cio_disable_subchannel(sch);
+	if (ret == -EBUSY)
+		vfio_ccw_sch_quiesce(sch);
+
+out_unlock:
+	private->state = VFIO_CCW_STATE_NOT_OPER;
+	spin_unlock_irq(sch->lock);
+	cp_free(&private->cp);
+}
+
  /*
   * Device statemachine
   */
@@ -390,6 +411,7 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
  		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_error,
  		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_disabled_irq,
  		[VFIO_CCW_EVENT_OPEN]		= fsm_open,
+		[VFIO_CCW_EVENT_CLOSE]		= fsm_nop,
  	},
  	[VFIO_CCW_STATE_STANDBY] = {
  		[VFIO_CCW_EVENT_NOT_OPER]	= fsm_notoper,
@@ -397,6 +419,7 @@ fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
  		[VFIO_CCW_EVENT_ASYNC_REQ]	= fsm_async_error,
  		[VFIO_CCW_EVENT_INTERRUPT]	= fsm_irq,
  		[VFIO_CCW_EVENT_OPEN]		= fsm_nop,
+		[VFIO_CCW_EVENT_CLOSE]		= fsm_notoper,

But if we are in STANDBY doesn't that imply we already did the OPEN? Don't we need to close it now before going NOT_OPER?





[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Kernel Development]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite Info]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Linux Media]     [Device Mapper]

  Powered by Linux