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path: root/drivers/s390/cio/device.c
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Diffstat (limited to 'drivers/s390/cio/device.c')
-rw-r--r--drivers/s390/cio/device.c75
1 files changed, 56 insertions, 19 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 039ef03cf21..cba33aa1df7 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -718,6 +718,8 @@ ccw_device_release(struct device *dev)
struct ccw_device *cdev;
cdev = to_ccwdev(dev);
+ /* Release reference of parent subchannel. */
+ put_device(cdev->dev.parent);
kfree(cdev->private);
kfree(cdev);
}
@@ -792,37 +794,55 @@ static void sch_attach_disconnected_device(struct subchannel *sch,
struct subchannel *other_sch;
int ret;
- other_sch = to_subchannel(get_device(cdev->dev.parent));
+ /* Get reference for new parent. */
+ if (!get_device(&sch->dev))
+ return;
+ other_sch = to_subchannel(cdev->dev.parent);
+ /* Note: device_move() changes cdev->dev.parent */
ret = device_move(&cdev->dev, &sch->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
"(ret=%d)!\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
- put_device(&other_sch->dev);
+ /* Put reference for new parent. */
+ put_device(&sch->dev);
return;
}
sch_set_cdev(other_sch, NULL);
/* No need to keep a subchannel without ccw device around. */
css_sch_device_unregister(other_sch);
- put_device(&other_sch->dev);
sch_attach_device(sch, cdev);
+ /* Put reference for old parent. */
+ put_device(&other_sch->dev);
}
static void sch_attach_orphaned_device(struct subchannel *sch,
struct ccw_device *cdev)
{
int ret;
+ struct subchannel *pseudo_sch;
- /* Try to move the ccw device to its new subchannel. */
+ /* Get reference for new parent. */
+ if (!get_device(&sch->dev))
+ return;
+ pseudo_sch = to_subchannel(cdev->dev.parent);
+ /*
+ * Try to move the ccw device to its new subchannel.
+ * Note: device_move() changes cdev->dev.parent
+ */
ret = device_move(&cdev->dev, &sch->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
"failed (ret=%d)!\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
+ /* Put reference for new parent. */
+ put_device(&sch->dev);
return;
}
sch_attach_device(sch, cdev);
+ /* Put reference on pseudo subchannel. */
+ put_device(&pseudo_sch->dev);
}
static void sch_create_and_recog_new_device(struct subchannel *sch)
@@ -844,9 +864,11 @@ static void sch_create_and_recog_new_device(struct subchannel *sch)
spin_lock_irq(sch->lock);
sch_set_cdev(sch, NULL);
spin_unlock_irq(sch->lock);
- if (cdev->dev.release)
- cdev->dev.release(&cdev->dev);
css_sch_device_unregister(sch);
+ /* Put reference from io_subchannel_create_ccwdev(). */
+ put_device(&sch->dev);
+ /* Give up initial reference. */
+ put_device(&cdev->dev);
}
}
@@ -868,15 +890,20 @@ void ccw_device_move_to_orphanage(struct work_struct *work)
dev_id.devno = sch->schib.pmcw.dev;
dev_id.ssid = sch->schid.ssid;
+ /* Increase refcount for pseudo subchannel. */
+ get_device(&css->pseudo_subchannel->dev);
/*
* Move the orphaned ccw device to the orphanage so the replacing
* ccw device can take its place on the subchannel.
+ * Note: device_move() changes cdev->dev.parent
*/
ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
if (ret) {
CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
"(ret=%d)!\n", cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
+ /* Decrease refcount for pseudo subchannel again. */
+ put_device(&css->pseudo_subchannel->dev);
return;
}
cdev->ccwlock = css->pseudo_subchannel->lock;
@@ -890,6 +917,8 @@ void ccw_device_move_to_orphanage(struct work_struct *work)
sch_attach_disconnected_device(sch, replacing_cdev);
/* Release reference from get_disc_ccwdev_by_dev_id() */
put_device(&replacing_cdev->dev);
+ /* Release reference of subchannel from old cdev. */
+ put_device(&sch->dev);
return;
}
replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
@@ -897,9 +926,13 @@ void ccw_device_move_to_orphanage(struct work_struct *work)
sch_attach_orphaned_device(sch, replacing_cdev);
/* Release reference from get_orphaned_ccwdev_by_dev_id() */
put_device(&replacing_cdev->dev);
+ /* Release reference of subchannel from old cdev. */
+ put_device(&sch->dev);
return;
}
sch_create_and_recog_new_device(sch);
+ /* Release reference of subchannel from old cdev. */
+ put_device(&sch->dev);
}
/*
@@ -948,13 +981,13 @@ io_subchannel_register(struct work_struct *work)
CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno, ret);
- put_device(&cdev->dev);
spin_lock_irqsave(sch->lock, flags);
sch_set_cdev(sch, NULL);
spin_unlock_irqrestore(sch->lock, flags);
- kfree (cdev->private);
- kfree (cdev);
- put_device(&sch->dev);
+ /* Release reference for workqueue processing. */
+ put_device(&cdev->dev);
+ /* Release initial device reference. */
+ put_device(&cdev->dev);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
return;
@@ -962,7 +995,6 @@ io_subchannel_register(struct work_struct *work)
put_device(&cdev->dev);
out:
cdev->private->flags.recog_done = 1;
- put_device(&sch->dev);
wake_up(&cdev->private->wait_q);
if (atomic_dec_and_test(&ccw_device_init_count))
wake_up(&ccw_device_init_wq);
@@ -1012,8 +1044,6 @@ 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;
@@ -1084,10 +1114,15 @@ static void ccw_device_move_to_sch(struct work_struct *work)
priv = container_of(work, struct ccw_device_private, kick_work);
sch = priv->sch;
cdev = priv->cdev;
- former_parent = ccw_device_is_orphan(cdev) ?
- NULL : to_subchannel(get_device(cdev->dev.parent));
+ former_parent = to_subchannel(cdev->dev.parent);
+ /* Get reference for new parent. */
+ if (!get_device(&sch->dev))
+ return;
mutex_lock(&sch->reg_mutex);
- /* Try to move the ccw device to its new subchannel. */
+ /*
+ * Try to move the ccw device to its new subchannel.
+ * Note: device_move() changes cdev->dev.parent
+ */
rc = device_move(&cdev->dev, &sch->dev);
mutex_unlock(&sch->reg_mutex);
if (rc) {
@@ -1097,9 +1132,11 @@ static void ccw_device_move_to_sch(struct work_struct *work)
cdev->private->dev_id.devno, sch->schid.ssid,
sch->schid.sch_no, rc);
css_sch_device_unregister(sch);
+ /* Put reference for new parent again. */
+ put_device(&sch->dev);
goto out;
}
- if (former_parent) {
+ if (!sch_is_pseudo_sch(former_parent)) {
spin_lock_irq(former_parent->lock);
sch_set_cdev(former_parent, NULL);
spin_unlock_irq(former_parent->lock);
@@ -1110,8 +1147,8 @@ static void ccw_device_move_to_sch(struct work_struct *work)
}
sch_attach_device(sch, cdev);
out:
- if (former_parent)
- put_device(&former_parent->dev);
+ /* Put reference for old parent. */
+ put_device(&former_parent->dev);
put_device(&cdev->dev);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-02 07:00:03 +0000