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authorCornelia Huck <cornelia.huck@de.ibm.com>2006-12-08 15:54:28 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-12-08 15:54:28 +0100
commitd7b5a4c94f49131811112526f7d404a50f0b5ca7 (patch)
tree159cb6717e16339b821315c0bc6b17b6f5df5119 /drivers/s390
parent2ec2298412e1ab4674b3780005058d4f0b8bd858 (diff)
downloadlinux-d7b5a4c94f49131811112526f7d404a50f0b5ca7.tar.bz2
[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>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/cio.c6
-rw-r--r--drivers/s390/cio/cio.h2
-rw-r--r--drivers/s390/cio/css.c37
-rw-r--r--drivers/s390/cio/css.h4
-rw-r--r--drivers/s390/cio/device.c287
-rw-r--r--drivers/s390/cio/device.h2
-rw-r--r--drivers/s390/cio/device_fsm.c17
7 files changed, 296 insertions, 59 deletions
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index e8d331493fd8..7835a714a405 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -415,6 +415,8 @@ cio_enable_subchannel (struct subchannel *sch, unsigned int isc)
CIO_TRACE_EVENT (2, "ensch");
CIO_TRACE_EVENT (2, sch->dev.bus_id);
+ if (sch_is_pseudo_sch(sch))
+ return -EINVAL;
ccode = stsch (sch->schid, &sch->schib);
if (ccode)
return -ENODEV;
@@ -462,6 +464,8 @@ cio_disable_subchannel (struct subchannel *sch)
CIO_TRACE_EVENT (2, "dissch");
CIO_TRACE_EVENT (2, sch->dev.bus_id);
+ if (sch_is_pseudo_sch(sch))
+ return 0;
ccode = stsch (sch->schid, &sch->schib);
if (ccode == 3) /* Not operational. */
return -ENODEV;
@@ -496,7 +500,7 @@ cio_disable_subchannel (struct subchannel *sch)
return ret;
}
-static int cio_create_sch_lock(struct subchannel *sch)
+int cio_create_sch_lock(struct subchannel *sch)
{
sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
if (!sch->lock)
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 7e7369b21a93..35154a210357 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -131,6 +131,8 @@ extern int cio_set_options (struct subchannel *, int);
extern int cio_get_options (struct subchannel *);
extern int cio_modify (struct subchannel *);
+int cio_create_sch_lock(struct subchannel *);
+
/* Use with care. */
#ifdef CONFIG_CCW_CONSOLE
extern struct subchannel *cio_probe_console(void);
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 65939e2eb415..0bf716619378 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -580,12 +580,24 @@ css_cm_enable_store(struct device *dev, struct device_attribute *attr,
static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
-static inline void __init
-setup_css(int nr)
+static inline int __init setup_css(int nr)
{
u32 tod_high;
+ int ret;
memset(css[nr], 0, sizeof(struct channel_subsystem));
+ css[nr]->pseudo_subchannel =
+ kzalloc(sizeof(*css[nr]->pseudo_subchannel), GFP_KERNEL);
+ if (!css[nr]->pseudo_subchannel)
+ return -ENOMEM;
+ css[nr]->pseudo_subchannel->dev.parent = &css[nr]->device;
+ css[nr]->pseudo_subchannel->dev.release = css_subchannel_release;
+ sprintf(css[nr]->pseudo_subchannel->dev.bus_id, "defunct");
+ ret = cio_create_sch_lock(css[nr]->pseudo_subchannel);
+ if (ret) {
+ kfree(css[nr]->pseudo_subchannel);
+ return ret;
+ }
mutex_init(&css[nr]->mutex);
css[nr]->valid = 1;
css[nr]->cssid = nr;
@@ -593,6 +605,7 @@ setup_css(int nr)
css[nr]->device.release = channel_subsystem_release;
tod_high = (u32) (get_clock() >> 32);
css_generate_pgid(css[nr], tod_high);
+ return 0;
}
/*
@@ -629,10 +642,12 @@ init_channel_subsystem (void)
ret = -ENOMEM;
goto out_unregister;
}
- setup_css(i);
- ret = device_register(&css[i]->device);
+ ret = setup_css(i);
if (ret)
goto out_free;
+ ret = device_register(&css[i]->device);
+ if (ret)
+ goto out_free_all;
if (css_characteristics_avail &&
css_chsc_characteristics.secm) {
ret = device_create_file(&css[i]->device,
@@ -640,6 +655,9 @@ init_channel_subsystem (void)
if (ret)
goto out_device;
}
+ ret = device_register(&css[i]->pseudo_subchannel->dev);
+ if (ret)
+ goto out_file;
}
css_init_done = 1;
@@ -647,13 +665,19 @@ init_channel_subsystem (void)
for_each_subchannel(__init_channel_subsystem, NULL);
return 0;
+out_file:
+ device_remove_file(&css[i]->device, &dev_attr_cm_enable);
out_device:
device_unregister(&css[i]->device);
+out_free_all:
+ kfree(css[i]->pseudo_subchannel->lock);
+ kfree(css[i]->pseudo_subchannel);
out_free:
kfree(css[i]);
out_unregister:
while (i > 0) {
i--;
+ device_unregister(&css[i]->pseudo_subchannel->dev);
if (css_characteristics_avail && css_chsc_characteristics.secm)
device_remove_file(&css[i]->device,
&dev_attr_cm_enable);
@@ -665,6 +689,11 @@ out:
return ret;
}
+int sch_is_pseudo_sch(struct subchannel *sch)
+{
+ return sch == to_css(sch->dev.parent)->pseudo_subchannel;
+}
+
/*
* find a driver for a subchannel. They identify by the subchannel
* type with the exception that the console subchannel driver has its own
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index ac845c1ebf83..71fe380f86f6 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -160,6 +160,8 @@ struct channel_subsystem {
int cm_enabled;
void *cub_addr1;
void *cub_addr2;
+ /* for orphaned ccw devices */
+ struct subchannel *pseudo_subchannel;
};
#define to_css(dev) container_of(dev, struct channel_subsystem, device)
@@ -187,6 +189,8 @@ void css_clear_subchannel_slow_list(void);
int css_slow_subchannels_exist(void);
extern int need_rescan;
+int sch_is_pseudo_sch(struct subchannel *);
+
extern struct workqueue_struct *slow_path_wq;
extern struct work_struct slow_path_work;
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 9a31239fe028..7fe1ccdc7812 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 @@ online_show (struct device *dev, struct device_attribute *attr, char *buf)
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 @@ static void
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 @@ available_show (struct device *dev, struct device_attribute *attr, char *buf)
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 @@ match_devno(struct device * dev, void * data)
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 @@ static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
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 @@ ccw_device_add_changed(struct work_struct *work)
}
}
-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 @@ static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
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 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
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 @@ io_subchannel_probe (struct subchannel *sch)
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);
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index d5fe95e04cfe..29db6341d632 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -80,6 +80,8 @@ int ccw_device_cancel_halt_clear(struct ccw_device *);
void ccw_device_do_unreg_rereg(struct work_struct *);
void ccw_device_call_sch_unregister(struct work_struct *);
+void ccw_device_move_to_orphanage(struct work_struct *);
+int ccw_device_is_orphan(struct ccw_device *);
int ccw_device_recognition(struct ccw_device *);
int ccw_device_online(struct ccw_device *);
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index a487fb0e7d3d..eed14572fc3b 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -186,13 +186,12 @@ ccw_device_handle_oper(struct ccw_device *cdev)
/*
* Check if cu type and device type still match. If
* not, it is certainly another device and we have to
- * de- and re-register. Also check here for non-matching devno.
+ * de- and re-register.
*/
if (cdev->id.cu_type != cdev->private->senseid.cu_type ||
cdev->id.cu_model != cdev->private->senseid.cu_model ||
cdev->id.dev_type != cdev->private->senseid.dev_type ||
- cdev->id.dev_model != cdev->private->senseid.dev_model ||
- cdev->private->dev_id.devno != sch->schib.pmcw.dev) {
+ cdev->id.dev_model != cdev->private->senseid.dev_model) {
PREPARE_WORK(&cdev->private->kick_work,
ccw_device_do_unreg_rereg);
queue_work(ccw_device_work, &cdev->private->kick_work);
@@ -676,6 +675,10 @@ ccw_device_offline(struct ccw_device *cdev)
{
struct subchannel *sch;
+ if (ccw_device_is_orphan(cdev)) {
+ ccw_device_done(cdev, DEV_STATE_OFFLINE);
+ return 0;
+ }
sch = to_subchannel(cdev->dev.parent);
if (stsch(sch->schid, &sch->schib) || !sch->schib.pmcw.dnv)
return -ENODEV;
@@ -1121,7 +1124,13 @@ device_trigger_reprobe(struct subchannel *sch)
sch->schib.pmcw.mp = 1;
sch->schib.pmcw.intparm = (__u32)(unsigned long)sch;
/* We should also udate ssd info, but this has to wait. */
- ccw_device_start_id(cdev, 0);
+ /* Check if this is another device which appeared on the same sch. */
+ if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
+ PREPARE_WORK(&cdev->private->kick_work,
+ ccw_device_move_to_orphanage);
+ queue_work(ccw_device_work, &cdev->private->kick_work);
+ } else
+ ccw_device_start_id(cdev, 0);
}
static void