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[S390] cio: move device unregistration to dedicated work queue

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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>
This commit is contained in:
Peter Oberparleiter 2008-10-10 21:33:05 +02:00 committed by Martin Schwidefsky
parent 4bcb3a3718
commit 46fbe4e46d
1 changed files with 25 additions and 31 deletions
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56
drivers/s390/cio/device.c
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@ -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;