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[S390] pm: tape power management callbacks

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Signed-off-by: Frank Munzert <munzert@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Frank Munzert
2009-06-16 10:30:39 +02:00
committed by Martin Schwidefsky
parent 9f62fa1618
commit 3ef32e62cb
4 changed files with 57 additions and 4 deletions
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52
drivers/s390/char/tape_core.c
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@@ -3,7 +3,7 @@
* basic function of the tape device driver
*
* S390 and zSeries version
* Copyright IBM Corp. 2001,2006
* Copyright IBM Corp. 2001, 2009
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Michael Holzheu <holzheu@de.ibm.com>
* Tuan Ngo-Anh <ngoanh@de.ibm.com>
@@ -379,6 +379,55 @@ tape_cleanup_device(struct tape_device *device)
tape_med_state_set(device, MS_UNKNOWN);
}
/*
* Suspend device.
*
* Called by the common I/O layer if the drive should be suspended on user
* request. We refuse to suspend if the device is loaded or in use for the
* following reason:
* While the Linux guest is suspended, it might be logged off which causes
* devices to be detached. Tape devices are automatically rewound and unloaded
* during DETACH processing (unless the tape device was attached with the
* NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
* resume the original state of the tape device, since we would need to
* manually re-load the cartridge which was active at suspend time.
*/
int tape_generic_pm_suspend(struct ccw_device *cdev)
{
struct tape_device *device;
device = cdev->dev.driver_data;
if (!device) {
return -ENODEV;
}
DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
device->cdev_id, device);
if (device->medium_state != MS_UNLOADED) {
pr_err("A cartridge is loaded in tape device %s, "
"refusing to suspend\n", dev_name(&cdev->dev));
return -EBUSY;
}
spin_lock_irq(get_ccwdev_lock(device->cdev));
switch (device->tape_state) {
case TS_INIT:
case TS_NOT_OPER:
case TS_UNUSED:
spin_unlock_irq(get_ccwdev_lock(device->cdev));
break;
default:
pr_err("Tape device %s is busy, refusing to "
"suspend\n", dev_name(&cdev->dev));
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return -EBUSY;
}
DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
return 0;
}
/*
* Set device offline.
*
@@ -1273,6 +1322,7 @@ EXPORT_SYMBOL(tape_generic_remove);
EXPORT_SYMBOL(tape_generic_probe);
EXPORT_SYMBOL(tape_generic_online);
EXPORT_SYMBOL(tape_generic_offline);
EXPORT_SYMBOL(tape_generic_pm_suspend);
EXPORT_SYMBOL(tape_put_device);
EXPORT_SYMBOL(tape_get_device_reference);
EXPORT_SYMBOL(tape_state_verbose);