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authorPeter Oberparleiter <peter.oberparleiter@de.ibm.com>2008-10-10 21:33:05 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-10-10 21:33:47 +0200
commit46fbe4e46ddb88805245a24f684400b50ead68a7 (patch)
tree0a8257d7802a8b15567bc8275b770a6b79e69a9d /drivers
parent4bcb3a37180ee4dffaef8298f373b334a7bedabb (diff)
[S390] cio: move device unregistration to dedicated work queue
Use dedicated slow path work queue when unregistering a device due to a user action. This ensures serialialization of other register/ unregister requests. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/s390/cio/device.c56
1 files changed, 25 insertions, 31 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 28221030b88..38a79ecfc74 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -296,36 +296,33 @@ static void ccw_device_unregister(struct ccw_device *cdev)
device_del(&cdev->dev);
}
-static void ccw_device_remove_orphan_cb(struct device *dev)
+static void ccw_device_remove_orphan_cb(struct work_struct *work)
{
- struct ccw_device *cdev = to_ccwdev(dev);
+ struct ccw_device_private *priv;
+ struct ccw_device *cdev;
+ priv = container_of(work, struct ccw_device_private, kick_work);
+ cdev = priv->cdev;
ccw_device_unregister(cdev);
put_device(&cdev->dev);
+ /* Release cdev reference for workqueue processing. */
+ put_device(&cdev->dev);
}
-static void ccw_device_remove_sch_cb(struct device *dev)
-{
- struct subchannel *sch;
-
- sch = to_subchannel(dev);
- css_sch_device_unregister(sch);
- /* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
- put_device(&sch->dev);
-}
+static void ccw_device_call_sch_unregister(struct work_struct *work);
static void
ccw_device_remove_disconnected(struct ccw_device *cdev)
{
unsigned long flags;
- int rc;
/*
* Forced offline in disconnected state means
* 'throw away device'.
*/
+ /* Get cdev reference for workqueue processing. */
+ if (!get_device(&cdev->dev))
+ return;
if (ccw_device_is_orphan(cdev)) {
/*
* Deregister ccw device.
@@ -335,23 +332,13 @@ ccw_device_remove_disconnected(struct ccw_device *cdev)
spin_lock_irqsave(cdev->ccwlock, flags);
cdev->private->state = DEV_STATE_NOT_OPER;
spin_unlock_irqrestore(cdev->ccwlock, flags);
- rc = device_schedule_callback(&cdev->dev,
- ccw_device_remove_orphan_cb);
- if (rc)
- CIO_MSG_EVENT(0, "Couldn't unregister orphan "
- "0.%x.%04x\n",
- cdev->private->dev_id.ssid,
- cdev->private->dev_id.devno);
- return;
- }
- /* Deregister subchannel, which will kill the ccw device. */
- rc = device_schedule_callback(cdev->dev.parent,
- ccw_device_remove_sch_cb);
- if (rc)
- CIO_MSG_EVENT(0, "Couldn't unregister disconnected device "
- "0.%x.%04x\n",
- cdev->private->dev_id.ssid,
- cdev->private->dev_id.devno);
+ PREPARE_WORK(&cdev->private->kick_work,
+ ccw_device_remove_orphan_cb);
+ } else
+ /* Deregister subchannel, which will kill the ccw device. */
+ PREPARE_WORK(&cdev->private->kick_work,
+ ccw_device_call_sch_unregister);
+ queue_work(slow_path_wq, &cdev->private->kick_work);
}
/**
@@ -970,12 +957,17 @@ static void ccw_device_call_sch_unregister(struct work_struct *work)
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
+ /* Get subchannel reference for local processing. */
+ if (!get_device(cdev->dev.parent))
+ return;
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
sch->schib.pmcw.intparm = 0;
cio_modify(sch);
+ /* Release cdev reference for workqueue processing.*/
put_device(&cdev->dev);
+ /* Release subchannel reference for local processing. */
put_device(&sch->dev);
}
@@ -1001,6 +993,8 @@ io_subchannel_recog_done(struct ccw_device *cdev)
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_call_sch_unregister);
queue_work(slow_path_wq, &cdev->private->kick_work);
+ /* Release subchannel reference for asynchronous recognition. */
+ put_device(&sch->dev);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
break;