[S390] Support for disconnected devices reappearing on another subchannel.
- create a 'pseudo_subchannel' per channel subsystem (the 'orphanage')
- use the orphanage as a shelter for ccw_devices that can't remain on the same
subchannel
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 9a31239f..7fe1ccd 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -23,6 +23,7 @@
#include <asm/param.h> /* HZ */
#include "cio.h"
+#include "cio_debug.h"
#include "css.h"
#include "device.h"
#include "ioasm.h"
@@ -294,6 +295,11 @@
return sprintf(buf, cdev->online ? "1\n" : "0\n");
}
+int ccw_device_is_orphan(struct ccw_device *cdev)
+{
+ return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
+}
+
static void ccw_device_unregister(struct work_struct *work)
{
struct ccw_device_private *priv;
@@ -310,10 +316,23 @@
ccw_device_remove_disconnected(struct ccw_device *cdev)
{
struct subchannel *sch;
+ unsigned long flags;
/*
* Forced offline in disconnected state means
* 'throw away device'.
*/
+ if (ccw_device_is_orphan(cdev)) {
+ /* Deregister ccw device. */
+ spin_lock_irqsave(cdev->ccwlock, flags);
+ cdev->private->state = DEV_STATE_NOT_OPER;
+ spin_unlock_irqrestore(cdev->ccwlock, flags);
+ if (get_device(&cdev->dev)) {
+ PREPARE_WORK(&cdev->private->kick_work,
+ ccw_device_unregister);
+ queue_work(ccw_device_work, &cdev->private->kick_work);
+ }
+ return ;
+ }
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
@@ -474,6 +493,8 @@
struct ccw_device *cdev = to_ccwdev(dev);
struct subchannel *sch;
+ if (ccw_device_is_orphan(cdev))
+ return sprintf(buf, "no device\n");
switch (cdev->private->state) {
case DEV_STATE_BOXED:
return sprintf(buf, "boxed\n");
@@ -574,11 +595,10 @@
cdev = to_ccwdev(dev);
if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
+ !ccw_device_is_orphan(cdev) &&
ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
- (cdev != d->sibling)) {
- cdev->private->state = DEV_STATE_NOT_OPER;
+ (cdev != d->sibling))
return 1;
- }
return 0;
}
@@ -595,6 +615,28 @@
return dev ? to_ccwdev(dev) : NULL;
}
+static int match_orphan(struct device *dev, void *data)
+{
+ struct ccw_dev_id *dev_id;
+ struct ccw_device *cdev;
+
+ dev_id = data;
+ cdev = to_ccwdev(dev);
+ return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
+}
+
+static struct ccw_device *
+get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
+ struct ccw_dev_id *dev_id)
+{
+ struct device *dev;
+
+ dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
+ match_orphan);
+
+ return dev ? to_ccwdev(dev) : NULL;
+}
+
static void
ccw_device_add_changed(struct work_struct *work)
{
@@ -614,64 +656,19 @@
}
}
-extern int css_get_ssd_info(struct subchannel *sch);
-
-void
-ccw_device_do_unreg_rereg(struct work_struct *work)
+void ccw_device_do_unreg_rereg(struct work_struct *work)
{
struct ccw_device_private *priv;
struct ccw_device *cdev;
struct subchannel *sch;
- int need_rename;
priv = container_of(work, struct ccw_device_private, kick_work);
cdev = priv->cdev;
sch = to_subchannel(cdev->dev.parent);
- if (cdev->private->dev_id.devno != sch->schib.pmcw.dev) {
- /*
- * The device number has changed. This is usually only when
- * a device has been detached under VM and then re-appeared
- * on another subchannel because of a different attachment
- * order than before. Ideally, we should should just switch
- * subchannels, but unfortunately, this is not possible with
- * the current implementation.
- * Instead, we search for the old subchannel for this device
- * number and deregister so there are no collisions with the
- * newly registered ccw_device.
- * FIXME: Find another solution so the block layer doesn't
- * get possibly sick...
- */
- struct ccw_device *other_cdev;
- struct ccw_dev_id dev_id;
- need_rename = 1;
- dev_id.devno = sch->schib.pmcw.dev;
- dev_id.ssid = sch->schid.ssid;
- other_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
- if (other_cdev) {
- struct subchannel *other_sch;
-
- other_sch = to_subchannel(other_cdev->dev.parent);
- if (get_device(&other_sch->dev)) {
- stsch(other_sch->schid, &other_sch->schib);
- if (other_sch->schib.pmcw.dnv) {
- other_sch->schib.pmcw.intparm = 0;
- cio_modify(other_sch);
- }
- css_sch_device_unregister(other_sch);
- }
- }
- /* Update ssd info here. */
- css_get_ssd_info(sch);
- cdev->private->dev_id.devno = sch->schib.pmcw.dev;
- } else
- need_rename = 0;
device_remove_files(&cdev->dev);
if (test_and_clear_bit(1, &cdev->private->registered))
device_del(&cdev->dev);
- if (need_rename)
- snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
- sch->schid.ssid, sch->schib.pmcw.dev);
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_add_changed);
queue_work(ccw_device_work, &cdev->private->kick_work);
@@ -736,6 +733,131 @@
return cdev;
}
+static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
+
+static void sch_attach_device(struct subchannel *sch,
+ struct ccw_device *cdev)
+{
+ spin_lock_irq(sch->lock);
+ sch->dev.driver_data = cdev;
+ cdev->private->schid = sch->schid;
+ cdev->ccwlock = sch->lock;
+ device_trigger_reprobe(sch);
+ spin_unlock_irq(sch->lock);
+}
+
+static void sch_attach_disconnected_device(struct subchannel *sch,
+ struct ccw_device *cdev)
+{
+ struct subchannel *other_sch;
+ int ret;
+
+ other_sch = to_subchannel(get_device(cdev->dev.parent));
+ ret = device_move(&cdev->dev, &sch->dev);
+ if (ret) {
+ CIO_MSG_EVENT(2, "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);
+ return;
+ }
+ other_sch->dev.driver_data = 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);
+}
+
+static void sch_attach_orphaned_device(struct subchannel *sch,
+ struct ccw_device *cdev)
+{
+ int ret;
+
+ /* Try to move the ccw device to its new subchannel. */
+ 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);
+ return;
+ }
+ sch_attach_device(sch, cdev);
+}
+
+static void sch_create_and_recog_new_device(struct subchannel *sch)
+{
+ struct ccw_device *cdev;
+
+ /* Need to allocate a new ccw device. */
+ cdev = io_subchannel_create_ccwdev(sch);
+ if (IS_ERR(cdev)) {
+ /* OK, we did everything we could... */
+ css_sch_device_unregister(sch);
+ return;
+ }
+ spin_lock_irq(sch->lock);
+ sch->dev.driver_data = cdev;
+ spin_unlock_irq(sch->lock);
+ /* Start recognition for the new ccw device. */
+ if (io_subchannel_recog(cdev, sch)) {
+ spin_lock_irq(sch->lock);
+ sch->dev.driver_data = NULL;
+ spin_unlock_irq(sch->lock);
+ if (cdev->dev.release)
+ cdev->dev.release(&cdev->dev);
+ css_sch_device_unregister(sch);
+ }
+}
+
+
+void ccw_device_move_to_orphanage(struct work_struct *work)
+{
+ struct ccw_device_private *priv;
+ struct ccw_device *cdev;
+ struct ccw_device *replacing_cdev;
+ struct subchannel *sch;
+ int ret;
+ struct channel_subsystem *css;
+ struct ccw_dev_id dev_id;
+
+ priv = container_of(work, struct ccw_device_private, kick_work);
+ cdev = priv->cdev;
+ sch = to_subchannel(cdev->dev.parent);
+ css = to_css(sch->dev.parent);
+ dev_id.devno = sch->schib.pmcw.dev;
+ dev_id.ssid = sch->schid.ssid;
+
+ /*
+ * Move the orphaned ccw device to the orphanage so the replacing
+ * ccw device can take its place on the subchannel.
+ */
+ 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);
+ return;
+ }
+ cdev->ccwlock = css->pseudo_subchannel->lock;
+ /*
+ * Search for the replacing ccw device
+ * - among the disconnected devices
+ * - in the orphanage
+ */
+ replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
+ if (replacing_cdev) {
+ sch_attach_disconnected_device(sch, replacing_cdev);
+ return;
+ }
+ replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
+ if (replacing_cdev) {
+ sch_attach_orphaned_device(sch, replacing_cdev);
+ return;
+ }
+ sch_create_and_recog_new_device(sch);
+}
+
/*
* Register recognized device.
*/
@@ -890,12 +1012,55 @@
return rc;
}
+static void ccw_device_move_to_sch(struct work_struct *work)
+{
+ struct ccw_device_private *priv;
+ int rc;
+ struct subchannel *sch;
+ struct ccw_device *cdev;
+ struct subchannel *former_parent;
+
+ 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));
+ mutex_lock(&sch->reg_mutex);
+ /* Try to move the ccw device to its new subchannel. */
+ rc = device_move(&cdev->dev, &sch->dev);
+ mutex_unlock(&sch->reg_mutex);
+ if (rc) {
+ CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
+ "0.%x.%04x failed (ret=%d)!\n",
+ cdev->private->dev_id.ssid,
+ cdev->private->dev_id.devno, sch->schid.ssid,
+ sch->schid.sch_no, rc);
+ css_sch_device_unregister(sch);
+ goto out;
+ }
+ if (former_parent) {
+ spin_lock_irq(former_parent->lock);
+ former_parent->dev.driver_data = NULL;
+ spin_unlock_irq(former_parent->lock);
+ css_sch_device_unregister(former_parent);
+ /* Reset intparm to zeroes. */
+ former_parent->schib.pmcw.intparm = 0;
+ cio_modify(former_parent);
+ }
+ sch_attach_device(sch, cdev);
+out:
+ if (former_parent)
+ put_device(&former_parent->dev);
+ put_device(&cdev->dev);
+}
+
static int
io_subchannel_probe (struct subchannel *sch)
{
struct ccw_device *cdev;
int rc;
unsigned long flags;
+ struct ccw_dev_id dev_id;
if (sch->dev.driver_data) {
/*
@@ -918,6 +1083,28 @@
get_device(&cdev->dev);
return 0;
}
+ /*
+ * First check if a fitting device may be found amongst the
+ * disconnected devices or in the orphanage.
+ */
+ dev_id.devno = sch->schib.pmcw.dev;
+ dev_id.ssid = sch->schid.ssid;
+ cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
+ if (!cdev)
+ cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
+ &dev_id);
+ if (cdev) {
+ /*
+ * Schedule moving the device until when we have a registered
+ * subchannel to move to and succeed the probe. We can
+ * unregister later again, when the probe is through.
+ */
+ cdev->private->sch = sch;
+ PREPARE_WORK(&cdev->private->kick_work,
+ ccw_device_move_to_sch);
+ queue_work(slow_path_wq, &cdev->private->kick_work);
+ return 0;
+ }
cdev = io_subchannel_create_ccwdev(sch);
if (IS_ERR(cdev))
return PTR_ERR(cdev);