From 48e4c385c5f54626651cca027afe242439281899 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:15 +0100
Subject: [S390] cio: fix double free in case of probe failure

io_subchannel_probe() frees memory for sch->private which is later
freed again when io_subchannel_remove() is called. Fix this problem
by removing the cleanup in io_subchannel_probe().

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 2490b741e16..55f997308e4 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1292,7 +1292,7 @@ static int io_subchannel_probe(struct subchannel *sch)
 	sch->private = kzalloc(sizeof(struct io_subchannel_private),
 			       GFP_KERNEL | GFP_DMA);
 	if (!sch->private)
-		goto out_err;
+		goto out_schedule;
 	/*
 	 * First check if a fitting device may be found amongst the
 	 * disconnected devices or in the orphanage.
@@ -1317,7 +1317,7 @@ static int io_subchannel_probe(struct subchannel *sch)
 	}
 	cdev = io_subchannel_create_ccwdev(sch);
 	if (IS_ERR(cdev))
-		goto out_err;
+		goto out_schedule;
 	rc = io_subchannel_recog(cdev, sch);
 	if (rc) {
 		spin_lock_irqsave(sch->lock, flags);
@@ -1325,9 +1325,7 @@ static int io_subchannel_probe(struct subchannel *sch)
 		spin_unlock_irqrestore(sch->lock, flags);
 	}
 	return 0;
-out_err:
-	kfree(sch->private);
-	sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
+
 out_schedule:
 	io_subchannel_schedule_removal(sch);
 	return 0;
@@ -1341,13 +1339,14 @@ io_subchannel_remove (struct subchannel *sch)
 
 	cdev = sch_get_cdev(sch);
 	if (!cdev)
-		return 0;
+		goto out_free;
 	/* Set ccw device to not operational and drop reference. */
 	spin_lock_irqsave(cdev->ccwlock, flags);
 	sch_set_cdev(sch, NULL);
 	cdev->private->state = DEV_STATE_NOT_OPER;
 	spin_unlock_irqrestore(cdev->ccwlock, flags);
 	ccw_device_unregister(cdev);
+out_free:
 	kfree(sch->private);
 	sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
 	return 0;
-- 
cgit v1.2.3-70-g09d2


From 60e4dac1abdf49ccdb7545ec406325f08423d848 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:16 +0100
Subject: [S390] cio: fix repeat setting of cdev parent association

sch_create_and_recog_new_device() associates a parent subchannel
with its ccw device child even though this is already done by
the subsequently called io_subchannel_recog(). Also make sure
io_subchannel_recog() sets the association under lock.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 55f997308e4..0efecefdb83 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -888,9 +888,6 @@ static void sch_create_and_recog_new_device(struct subchannel *sch)
 		css_sch_device_unregister(sch);
 		return;
 	}
-	spin_lock_irq(sch->lock);
-	sch_set_cdev(sch, cdev);
-	spin_unlock_irq(sch->lock);
 	/* Start recognition for the new ccw device. */
 	if (io_subchannel_recog(cdev, sch)) {
 		spin_lock_irq(sch->lock);
@@ -1107,7 +1104,6 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 	int rc;
 	struct ccw_device_private *priv;
 
-	sch_set_cdev(sch, cdev);
 	cdev->ccwlock = sch->lock;
 
 	/* Init private data. */
@@ -1125,6 +1121,7 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 
 	/* Start async. device sensing. */
 	spin_lock_irq(sch->lock);
+	sch_set_cdev(sch, cdev);
 	rc = ccw_device_recognition(cdev);
 	spin_unlock_irq(sch->lock);
 	if (rc) {
-- 
cgit v1.2.3-70-g09d2


From 5d6e6b6f6f3eac10a7f5a15e961bac3b36824d9d Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:17 +0100
Subject: [S390] cio: introduce parent-initiated device move

Change the initiative to update subchannel-ccw device associations
to the subchannel: when there is an indication that the internal
association no longer reflects the current hardware state, mark
each affected subchannel as requiring attention. Once processing
reaches a subchannel, determine the correct association for that
subchannel at that time and perform the necessary device_move
operations.

This change fixes problems with the previous approach which would
leave devices in an inconsistent state when a new hardware change
occurred while a device_move was already scheduled.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/css.c        |   9 +-
 drivers/s390/cio/device.c     | 513 +++++++++++++++---------------------------
 drivers/s390/cio/device_fsm.c |   8 +-
 3 files changed, 192 insertions(+), 338 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 91c25706fa8..b4df5a56cfe 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -376,8 +376,8 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
 		/* Unusable - ignore. */
 		return 0;
 	}
-	CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
-			 "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
+	CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
+		      schid.sch_no);
 
 	return css_probe_device(schid);
 }
@@ -394,6 +394,10 @@ static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
 				"Got subchannel machine check but "
 				"no sch_event handler provided.\n");
 	}
+	if (ret != 0 && ret != -EAGAIN) {
+		CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
+			      sch->schid.ssid, sch->schid.sch_no, ret);
+	}
 	return ret;
 }
 
@@ -684,6 +688,7 @@ static int __init setup_css(int nr)
 	css->pseudo_subchannel->dev.parent = &css->device;
 	css->pseudo_subchannel->dev.release = css_subchannel_release;
 	dev_set_name(&css->pseudo_subchannel->dev, "defunct");
+	mutex_init(&css->pseudo_subchannel->reg_mutex);
 	ret = cio_create_sch_lock(css->pseudo_subchannel);
 	if (ret) {
 		kfree(css->pseudo_subchannel);
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 0efecefdb83..6097763f103 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -673,57 +673,19 @@ static int ccw_device_register(struct ccw_device *cdev)
 	return ret;
 }
 
-struct match_data {
-	struct ccw_dev_id dev_id;
-	struct ccw_device * sibling;
-};
-
-static int
-match_devno(struct device * dev, void * data)
-{
-	struct match_data * d = data;
-	struct ccw_device * cdev;
-
-	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))
-		return 1;
-	return 0;
-}
-
-static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
-						     struct ccw_device *sibling)
+static int match_dev_id(struct device *dev, void *data)
 {
-	struct device *dev;
-	struct match_data data;
-
-	data.dev_id = *dev_id;
-	data.sibling = sibling;
-	dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
-
-	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;
+	struct ccw_device *cdev = to_ccwdev(dev);
+	struct ccw_dev_id *dev_id = data;
 
-	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)
+static struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 {
 	struct device *dev;
 
-	dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
-				match_orphan);
+	dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 
 	return dev ? to_ccwdev(dev) : NULL;
 }
@@ -808,75 +770,6 @@ static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 
 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 
-static void sch_attach_device(struct subchannel *sch,
-			      struct ccw_device *cdev)
-{
-	css_update_ssd_info(sch);
-	spin_lock_irq(sch->lock);
-	sch_set_cdev(sch, cdev);
-	cdev->private->schid = sch->schid;
-	cdev->ccwlock = sch->lock;
-	ccw_device_trigger_reprobe(cdev);
-	spin_unlock_irq(sch->lock);
-}
-
-static void sch_attach_disconnected_device(struct subchannel *sch,
-					   struct ccw_device *cdev)
-{
-	struct subchannel *other_sch;
-	int ret;
-
-	/* 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, DPM_ORDER_PARENT_BEFORE_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 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);
-	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;
-
-	/* 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, DPM_ORDER_PARENT_BEFORE_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)
 {
 	struct ccw_device *cdev;
@@ -901,70 +794,6 @@ static void sch_create_and_recog_new_device(struct subchannel *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;
-
-	/* 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,
-		DPM_ORDER_NONE);
-	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;
-	/*
-	 * 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);
-		/* 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);
-	if (replacing_cdev) {
-		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);
-}
-
 /*
  * Register recognized device.
  */
@@ -1131,53 +960,56 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 	return rc;
 }
 
-static void ccw_device_move_to_sch(struct work_struct *work)
+static int ccw_device_move_to_sch(struct ccw_device *cdev,
+				  struct subchannel *sch)
 {
-	struct ccw_device_private *priv;
+	struct subchannel *old_sch;
 	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 = to_subchannel(cdev->dev.parent);
-	/* Get reference for new parent. */
+	old_sch = to_subchannel(cdev->dev.parent);
+	/* Obtain child reference for new parent. */
 	if (!get_device(&sch->dev))
-		return;
+		return -ENODEV;
 	mutex_lock(&sch->reg_mutex);
-	/*
-	 * Try to move the ccw device to its new subchannel.
-	 * Note: device_move() changes cdev->dev.parent
-	 */
 	rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 	mutex_unlock(&sch->reg_mutex);
 	if (rc) {
-		CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
-			      "0.%x.%04x failed (ret=%d)!\n",
+		CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%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);
-		/* Put reference for new parent again. */
+			      sch->schib.pmcw.dev, rc);
+		/* Release child reference for new parent. */
 		put_device(&sch->dev);
-		goto out;
+		return rc;
 	}
-	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);
-		css_sch_device_unregister(former_parent);
-		/* Reset intparm to zeroes. */
-		former_parent->config.intparm = 0;
-		cio_commit_config(former_parent);
+	/* Clean up old subchannel. */
+	if (!sch_is_pseudo_sch(old_sch)) {
+		spin_lock_irq(old_sch->lock);
+		sch_set_cdev(old_sch, NULL);
+		cio_disable_subchannel(old_sch);
+		spin_unlock_irq(old_sch->lock);
+		css_schedule_eval(old_sch->schid);
 	}
-	sch_attach_device(sch, cdev);
-out:
-	/* Put reference for old parent. */
-	put_device(&former_parent->dev);
-	put_device(&cdev->dev);
+	/* Release child reference for old parent. */
+	put_device(&old_sch->dev);
+	/* Initialize new subchannel. */
+	spin_lock_irq(sch->lock);
+	cdev->private->schid = sch->schid;
+	cdev->ccwlock = sch->lock;
+	if (!sch_is_pseudo_sch(sch))
+		sch_set_cdev(sch, cdev);
+	spin_unlock_irq(sch->lock);
+	if (!sch_is_pseudo_sch(sch))
+		css_update_ssd_info(sch);
+	return 0;
+}
+
+static int ccw_device_move_to_orph(struct ccw_device *cdev)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct channel_subsystem *css = to_css(sch->dev.parent);
+
+	return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 }
 
 static void io_subchannel_irq(struct subchannel *sch)
@@ -1244,8 +1076,6 @@ static int io_subchannel_probe(struct subchannel *sch)
 {
 	struct ccw_device *cdev;
 	int rc;
-	unsigned long flags;
-	struct ccw_dev_id dev_id;
 
 	if (cio_is_console(sch->schid)) {
 		rc = sysfs_create_group(&sch->dev.kobj,
@@ -1290,37 +1120,7 @@ static int io_subchannel_probe(struct subchannel *sch)
 			       GFP_KERNEL | GFP_DMA);
 	if (!sch->private)
 		goto out_schedule;
-	/*
-	 * 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))
-		goto out_schedule;
-	rc = io_subchannel_recog(cdev, sch);
-	if (rc) {
-		spin_lock_irqsave(sch->lock, flags);
-		io_subchannel_recog_done(cdev);
-		spin_unlock_irqrestore(sch->lock, flags);
-	}
+	css_schedule_eval(sch->schid);
 	return 0;
 
 out_schedule:
@@ -1349,16 +1149,6 @@ out_free:
 	return 0;
 }
 
-static int io_subchannel_notify(struct subchannel *sch, int event)
-{
-	struct ccw_device *cdev;
-
-	cdev = sch_get_cdev(sch);
-	if (!cdev)
-		return 0;
-	return ccw_device_notify(cdev, event);
-}
-
 static void io_subchannel_verify(struct subchannel *sch)
 {
 	struct ccw_device *cdev;
@@ -1482,19 +1272,6 @@ io_subchannel_shutdown(struct subchannel *sch)
 	cio_disable_subchannel(sch);
 }
 
-static int io_subchannel_get_status(struct subchannel *sch)
-{
-	struct schib schib;
-
-	if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
-		return CIO_GONE;
-	if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
-		return CIO_REVALIDATE;
-	if (!sch->lpm)
-		return CIO_NO_PATH;
-	return CIO_OPER;
-}
-
 static int device_is_disconnected(struct ccw_device *cdev)
 {
 	if (!cdev)
@@ -1626,91 +1403,165 @@ void ccw_device_set_notoper(struct ccw_device *cdev)
 	cdev->private->state = DEV_STATE_NOT_OPER;
 }
 
-static int io_subchannel_sch_event(struct subchannel *sch, int slow)
+enum io_sch_action {
+	IO_SCH_UNREG,
+	IO_SCH_ORPH_UNREG,
+	IO_SCH_ATTACH,
+	IO_SCH_UNREG_ATTACH,
+	IO_SCH_ORPH_ATTACH,
+	IO_SCH_REPROBE,
+	IO_SCH_VERIFY,
+	IO_SCH_DISC,
+	IO_SCH_NOP,
+};
+
+static enum io_sch_action sch_get_action(struct subchannel *sch)
+{
+	struct ccw_device *cdev;
+
+	cdev = sch_get_cdev(sch);
+	if (cio_update_schib(sch)) {
+		/* Not operational. */
+		if (!cdev)
+			return IO_SCH_UNREG;
+		if (!ccw_device_notify(cdev, CIO_GONE))
+			return IO_SCH_UNREG;
+		return IO_SCH_ORPH_UNREG;
+	}
+	/* Operational. */
+	if (!cdev)
+		return IO_SCH_ATTACH;
+	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
+		if (!ccw_device_notify(cdev, CIO_GONE))
+			return IO_SCH_UNREG_ATTACH;
+		return IO_SCH_ORPH_ATTACH;
+	}
+	if ((sch->schib.pmcw.pam & sch->opm) == 0) {
+		if (!ccw_device_notify(cdev, CIO_NO_PATH))
+			return IO_SCH_UNREG;
+		return IO_SCH_DISC;
+	}
+	if (device_is_disconnected(cdev))
+		return IO_SCH_REPROBE;
+	if (cdev->online)
+		return IO_SCH_VERIFY;
+	return IO_SCH_NOP;
+}
+
+/**
+ * io_subchannel_sch_event - process subchannel event
+ * @sch: subchannel
+ * @process: non-zero if function is called in process context
+ *
+ * An unspecified event occurred for this subchannel. Adjust data according
+ * to the current operational state of the subchannel and device. Return
+ * zero when the event has been handled sufficiently or -EAGAIN when this
+ * function should be called again in process context.
+ */
+static int io_subchannel_sch_event(struct subchannel *sch, int process)
 {
-	int event, ret, disc;
 	unsigned long flags;
-	enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
 	struct ccw_device *cdev;
+	struct ccw_dev_id dev_id;
+	enum io_sch_action action;
+	int rc = -EAGAIN;
 
 	spin_lock_irqsave(sch->lock, flags);
+	if (!device_is_registered(&sch->dev))
+		goto out_unlock;
+	action = sch_get_action(sch);
+	CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
+		      sch->schid.ssid, sch->schid.sch_no, process,
+		      action);
+	/* Perform immediate actions while holding the lock. */
 	cdev = sch_get_cdev(sch);
-	disc = device_is_disconnected(cdev);
-	if (disc && slow) {
-		/* Disconnected devices are evaluated directly only.*/
-		spin_unlock_irqrestore(sch->lock, flags);
-		return 0;
-	}
-	/* No interrupt after machine check - kill pending timers. */
-	if (cdev)
-		ccw_device_set_timeout(cdev, 0);
-	if (!disc && !slow) {
-		/* Non-disconnected devices are evaluated on the slow path. */
-		spin_unlock_irqrestore(sch->lock, flags);
-		return -EAGAIN;
+	switch (action) {
+	case IO_SCH_REPROBE:
+		/* Trigger device recognition. */
+		ccw_device_trigger_reprobe(cdev);
+		rc = 0;
+		goto out_unlock;
+	case IO_SCH_VERIFY:
+		/* Trigger path verification. */
+		io_subchannel_verify(sch);
+		rc = 0;
+		goto out_unlock;
+	case IO_SCH_DISC:
+		ccw_device_set_disconnected(cdev);
+		rc = 0;
+		goto out_unlock;
+	case IO_SCH_ORPH_UNREG:
+	case IO_SCH_ORPH_ATTACH:
+		ccw_device_set_disconnected(cdev);
+		break;
+	case IO_SCH_UNREG_ATTACH:
+	case IO_SCH_UNREG:
+		if (cdev)
+			ccw_device_set_notoper(cdev);
+		break;
+	case IO_SCH_NOP:
+		rc = 0;
+		goto out_unlock;
+	default:
+		break;
 	}
-	event = io_subchannel_get_status(sch);
-	CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
-		      sch->schid.ssid, sch->schid.sch_no, event,
-		      disc ? "disconnected" : "normal",
-		      slow ? "slow" : "fast");
-	/* Analyze subchannel status. */
-	action = NONE;
-	switch (event) {
-	case CIO_NO_PATH:
-		if (disc) {
-			/* Check if paths have become available. */
-			action = REPROBE;
-			break;
-		}
-		/* fall through */
-	case CIO_GONE:
-		/* Ask driver what to do with device. */
-		if (io_subchannel_notify(sch, event))
-			action = DISC;
-		else
-			action = UNREGISTER;
+	spin_unlock_irqrestore(sch->lock, flags);
+	/* All other actions require process context. */
+	if (!process)
+		goto out;
+	/* Handle attached ccw device. */
+	switch (action) {
+	case IO_SCH_ORPH_UNREG:
+	case IO_SCH_ORPH_ATTACH:
+		/* Move ccw device to orphanage. */
+		rc = ccw_device_move_to_orph(cdev);
+		if (rc)
+			goto out;
 		break;
-	case CIO_REVALIDATE:
-		/* Device will be removed, so no notify necessary. */
-		if (disc)
-			/* Reprobe because immediate unregister might block. */
-			action = REPROBE;
-		else
-			action = UNREGISTER_PROBE;
+	case IO_SCH_UNREG_ATTACH:
+		/* Unregister ccw device. */
+		ccw_device_unregister(cdev);
 		break;
-	case CIO_OPER:
-		if (disc)
-			/* Get device operational again. */
-			action = REPROBE;
+	default:
 		break;
 	}
-	/* Perform action. */
-	ret = 0;
+	/* Handle subchannel. */
 	switch (action) {
-	case UNREGISTER:
-	case UNREGISTER_PROBE:
-		ccw_device_set_notoper(cdev);
-		/* Unregister device (will use subchannel lock). */
-		spin_unlock_irqrestore(sch->lock, flags);
+	case IO_SCH_ORPH_UNREG:
+	case IO_SCH_UNREG:
 		css_sch_device_unregister(sch);
-		spin_lock_irqsave(sch->lock, flags);
 		break;
-	case REPROBE:
+	case IO_SCH_ORPH_ATTACH:
+	case IO_SCH_UNREG_ATTACH:
+	case IO_SCH_ATTACH:
+		dev_id.ssid = sch->schid.ssid;
+		dev_id.devno = sch->schib.pmcw.dev;
+		cdev = get_ccwdev_by_dev_id(&dev_id);
+		if (!cdev) {
+			sch_create_and_recog_new_device(sch);
+			break;
+		}
+		rc = ccw_device_move_to_sch(cdev, sch);
+		if (rc) {
+			/* Release reference from get_ccwdev_by_dev_id() */
+			put_device(&cdev->dev);
+			goto out;
+		}
+		spin_lock_irqsave(sch->lock, flags);
 		ccw_device_trigger_reprobe(cdev);
-		break;
-	case DISC:
-		ccw_device_set_disconnected(cdev);
+		spin_unlock_irqrestore(sch->lock, flags);
+		/* Release reference from get_ccwdev_by_dev_id() */
+		put_device(&cdev->dev);
 		break;
 	default:
 		break;
 	}
-	spin_unlock_irqrestore(sch->lock, flags);
-	/* Probe if necessary. */
-	if (action == UNREGISTER_PROBE)
-		ret = css_probe_device(sch->schid);
+	return 0;
 
-	return ret;
+out_unlock:
+	spin_unlock_irqrestore(sch->lock, flags);
+out:
+	return rc;
 }
 
 #ifdef CONFIG_CCW_CONSOLE
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index b9613d7df9e..d1e05f44fb6 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -1072,11 +1072,9 @@ void ccw_device_trigger_reprobe(struct ccw_device *cdev)
 
 	/* We should also udate ssd info, but this has to wait. */
 	/* 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(slow_path_wq, &cdev->private->kick_work);
-	} else
+	if (sch->schib.pmcw.dev != cdev->private->dev_id.devno)
+		css_schedule_eval(sch->schid);
+	else
 		ccw_device_start_id(cdev, 0);
 }
 
-- 
cgit v1.2.3-70-g09d2


From 390935acac21f3ea1a130bdca8eb9397cb293643 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:18 +0100
Subject: [S390] cio: introduce subchannel todos

Ensure that current and future users of sch->work do not overwrite
each other by introducing a single mechanism for delayed subchannel
work.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/cio.h    |  8 +++++++-
 drivers/s390/cio/css.c    | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 drivers/s390/cio/css.h    |  3 +++
 drivers/s390/cio/device.c | 23 +++++------------------
 4 files changed, 63 insertions(+), 19 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 2e43558c704..bf7f80f5a33 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -68,6 +68,11 @@ struct schib {
 	__u8 mda[4];		 /* model dependent area */
 } __attribute__ ((packed,aligned(4)));
 
+enum sch_todo {
+	SCH_TODO_NOTHING,
+	SCH_TODO_UNREG,
+};
+
 /* subchannel data structure used by I/O subroutines */
 struct subchannel {
 	struct subchannel_id schid;
@@ -95,7 +100,8 @@ struct subchannel {
 	struct device dev;	/* entry in device tree */
 	struct css_driver *driver;
 	void *private; /* private per subchannel type data */
-	struct work_struct work;
+	enum sch_todo todo;
+	struct work_struct todo_work;
 	struct schib_config config;
 } __attribute__ ((aligned(8)));
 
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index b4df5a56cfe..92ff88ac110 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -133,6 +133,8 @@ out:
 	return rc;
 }
 
+static void css_sch_todo(struct work_struct *work);
+
 static struct subchannel *
 css_alloc_subchannel(struct subchannel_id schid)
 {
@@ -147,6 +149,7 @@ css_alloc_subchannel(struct subchannel_id schid)
 		kfree(sch);
 		return ERR_PTR(ret);
 	}
+	INIT_WORK(&sch->todo_work, css_sch_todo);
 	return sch;
 }
 
@@ -190,6 +193,51 @@ void css_sch_device_unregister(struct subchannel *sch)
 }
 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
 
+static void css_sch_todo(struct work_struct *work)
+{
+	struct subchannel *sch;
+	enum sch_todo todo;
+
+	sch = container_of(work, struct subchannel, todo_work);
+	/* Find out todo. */
+	spin_lock_irq(sch->lock);
+	todo = sch->todo;
+	CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
+		      sch->schid.sch_no, todo);
+	sch->todo = SCH_TODO_NOTHING;
+	spin_unlock_irq(sch->lock);
+	/* Perform todo. */
+	if (todo == SCH_TODO_UNREG)
+		css_sch_device_unregister(sch);
+	/* Release workqueue ref. */
+	put_device(&sch->dev);
+}
+
+/**
+ * css_sched_sch_todo - schedule a subchannel operation
+ * @sch: subchannel
+ * @todo: todo
+ *
+ * Schedule the operation identified by @todo to be performed on the slow path
+ * workqueue. Do nothing if another operation with higher priority is already
+ * scheduled. Needs to be called with subchannel lock held.
+ */
+void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
+{
+	CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
+		      sch->schid.ssid, sch->schid.sch_no, todo);
+	if (sch->todo >= todo)
+		return;
+	/* Get workqueue ref. */
+	if (!get_device(&sch->dev))
+		return;
+	sch->todo = todo;
+	if (!queue_work(slow_path_wq, &sch->todo_work)) {
+		/* Already queued, release workqueue ref. */
+		put_device(&sch->dev);
+	}
+}
+
 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
 {
 	int i;
diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index 68d6b0bf151..fe84b92cde6 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -11,6 +11,8 @@
 #include <asm/chpid.h>
 #include <asm/schid.h>
 
+#include "cio.h"
+
 /*
  * path grouping stuff
  */
@@ -151,4 +153,5 @@ int css_sch_is_valid(struct schib *);
 
 extern struct workqueue_struct *slow_path_wq;
 void css_wait_for_slow_path(void);
+void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo);
 #endif
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 6097763f103..0dcfc0ee3d8 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1051,23 +1051,6 @@ static void io_subchannel_init_fields(struct subchannel *sch)
 	io_subchannel_init_config(sch);
 }
 
-static void io_subchannel_do_unreg(struct work_struct *work)
-{
-	struct subchannel *sch;
-
-	sch = container_of(work, struct subchannel, work);
-	css_sch_device_unregister(sch);
-	put_device(&sch->dev);
-}
-
-/* Schedule unregister if we have no cdev. */
-static void io_subchannel_schedule_removal(struct subchannel *sch)
-{
-	get_device(&sch->dev);
-	INIT_WORK(&sch->work, io_subchannel_do_unreg);
-	queue_work(slow_path_wq, &sch->work);
-}
-
 /*
  * Note: We always return 0 so that we bind to the device even on error.
  * This is needed so that our remove function is called on unregister.
@@ -1124,7 +1107,9 @@ static int io_subchannel_probe(struct subchannel *sch)
 	return 0;
 
 out_schedule:
-	io_subchannel_schedule_removal(sch);
+	spin_lock_irq(sch->lock);
+	css_sched_sch_todo(sch, SCH_TODO_UNREG);
+	spin_unlock_irq(sch->lock);
 	return 0;
 }
 
@@ -1469,6 +1454,8 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
 	spin_lock_irqsave(sch->lock, flags);
 	if (!device_is_registered(&sch->dev))
 		goto out_unlock;
+	if (work_pending(&sch->todo_work))
+		goto out_unlock;
 	action = sch_get_action(sch);
 	CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
 		      sch->schid.ssid, sch->schid.sch_no, process,
-- 
cgit v1.2.3-70-g09d2


From 37de53bb52908726c18fc84515792a5b2f454532 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:19 +0100
Subject: [S390] cio: introduce ccw device todos

Introduce a central mechanism for performing delayed ccw device work
to ensure that different types of work do not overwrite each other.
Prioritization ensures that the most important work is always
performed while less important tasks are either obsoleted or repeated
later.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c     | 203 +++++++++++++++++++++---------------------
 drivers/s390/cio/device.h     |   3 +-
 drivers/s390/cio/device_fsm.c |  28 ++----
 drivers/s390/cio/io_sch.h     |  12 ++-
 4 files changed, 119 insertions(+), 127 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 0dcfc0ee3d8..167446785d1 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -306,47 +306,6 @@ static void ccw_device_unregister(struct ccw_device *cdev)
 	}
 }
 
-static void ccw_device_remove_orphan_cb(struct work_struct *work)
-{
-	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);
-	/* Release cdev reference for workqueue processing. */
-	put_device(&cdev->dev);
-}
-
-static void
-ccw_device_remove_disconnected(struct ccw_device *cdev)
-{
-	unsigned long flags;
-
-	/*
-	 * Forced offline in disconnected state means
-	 * 'throw away device'.
-	 */
-	if (ccw_device_is_orphan(cdev)) {
-		/*
-		 * Deregister ccw device.
-		 * Unfortunately, we cannot do this directly from the
-		 * attribute method.
-		 */
-		/* Get cdev reference for workqueue processing. */
-		if (!get_device(&cdev->dev))
-			return;
-		spin_lock_irqsave(cdev->ccwlock, flags);
-		cdev->private->state = DEV_STATE_NOT_OPER;
-		spin_unlock_irqrestore(cdev->ccwlock, flags);
-		PREPARE_WORK(&cdev->private->kick_work,
-				ccw_device_remove_orphan_cb);
-		queue_work(slow_path_wq, &cdev->private->kick_work);
-	} else
-		/* Deregister subchannel, which will kill the ccw device. */
-		ccw_device_schedule_sch_unregister(cdev);
-}
-
 /**
  * ccw_device_set_offline() - disable a ccw device for I/O
  * @cdev: target ccw device
@@ -494,9 +453,11 @@ error:
 
 static int online_store_handle_offline(struct ccw_device *cdev)
 {
-	if (cdev->private->state == DEV_STATE_DISCONNECTED)
-		ccw_device_remove_disconnected(cdev);
-	else if (cdev->online && cdev->drv && cdev->drv->set_offline)
+	if (cdev->private->state == DEV_STATE_DISCONNECTED) {
+		spin_lock_irq(cdev->ccwlock);
+		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
+		spin_unlock_irq(cdev->ccwlock);
+	} else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 		return ccw_device_set_offline(cdev);
 	return 0;
 }
@@ -690,17 +651,10 @@ static struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 	return dev ? to_ccwdev(dev) : NULL;
 }
 
-void ccw_device_do_unbind_bind(struct work_struct *work)
+static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 {
-	struct ccw_device_private *priv;
-	struct ccw_device *cdev;
-	struct subchannel *sch;
 	int ret;
 
-	priv = container_of(work, struct ccw_device_private, kick_work);
-	cdev = priv->cdev;
-	sch = to_subchannel(cdev->dev.parent);
-
 	if (test_bit(1, &cdev->private->registered)) {
 		device_release_driver(&cdev->dev);
 		ret = device_attach(&cdev->dev);
@@ -735,6 +689,8 @@ static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 	return ERR_PTR(-ENOMEM);
 }
 
+static void ccw_device_todo(struct work_struct *work);
+
 static int io_subchannel_initialize_dev(struct subchannel *sch,
 					struct ccw_device *cdev)
 {
@@ -742,7 +698,7 @@ static int io_subchannel_initialize_dev(struct subchannel *sch,
 	atomic_set(&cdev->private->onoff, 0);
 	cdev->dev.parent = &sch->dev;
 	cdev->dev.release = ccw_device_release;
-	INIT_WORK(&cdev->private->kick_work, NULL);
+	INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
 	cdev->dev.groups = ccwdev_attr_groups;
 	/* Do first half of device_register. */
 	device_initialize(&cdev->dev);
@@ -797,17 +753,12 @@ static void sch_create_and_recog_new_device(struct subchannel *sch)
 /*
  * Register recognized device.
  */
-static void
-io_subchannel_register(struct work_struct *work)
+static void io_subchannel_register(struct ccw_device *cdev)
 {
-	struct ccw_device_private *priv;
-	struct ccw_device *cdev;
 	struct subchannel *sch;
 	int ret;
 	unsigned long flags;
 
-	priv = container_of(work, struct ccw_device_private, kick_work);
-	cdev = priv->cdev;
 	sch = to_subchannel(cdev->dev.parent);
 	/*
 	 * Check if subchannel is still registered. It may have become
@@ -859,41 +810,23 @@ out:
 	cdev->private->flags.recog_done = 1;
 	wake_up(&cdev->private->wait_q);
 out_err:
-	/* Release reference for workqueue processing. */
-	put_device(&cdev->dev);
 	if (atomic_dec_and_test(&ccw_device_init_count))
 		wake_up(&ccw_device_init_wq);
 }
 
-static void ccw_device_call_sch_unregister(struct work_struct *work)
+static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 {
-	struct ccw_device_private *priv;
-	struct ccw_device *cdev;
 	struct subchannel *sch;
 
-	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);
-	/* Release cdev reference for workqueue processing.*/
-	put_device(&cdev->dev);
 	/* Release subchannel reference for local processing. */
 	put_device(&sch->dev);
 }
 
-void ccw_device_schedule_sch_unregister(struct ccw_device *cdev)
-{
-	/* Get cdev reference for workqueue processing. */
-	if (!get_device(&cdev->dev))
-		return;
-	PREPARE_WORK(&cdev->private->kick_work,
-		     ccw_device_call_sch_unregister);
-	queue_work(slow_path_wq, &cdev->private->kick_work);
-}
-
 /*
  * subchannel recognition done. Called from the state machine.
  */
@@ -909,7 +842,8 @@ io_subchannel_recog_done(struct ccw_device *cdev)
 		/* Device did not respond in time. */
 	case DEV_STATE_NOT_OPER:
 		cdev->private->flags.recog_done = 1;
-		ccw_device_schedule_sch_unregister(cdev);
+		/* Remove device found not operational. */
+		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 		if (atomic_dec_and_test(&ccw_device_init_count))
 			wake_up(&ccw_device_init_wq);
 		break;
@@ -918,11 +852,7 @@ io_subchannel_recog_done(struct ccw_device *cdev)
 		 * We can't register the device in interrupt context so
 		 * we schedule a work item.
 		 */
-		if (!get_device(&cdev->dev))
-			break;
-		PREPARE_WORK(&cdev->private->kick_work,
-			     io_subchannel_register);
-		queue_work(slow_path_wq, &cdev->private->kick_work);
+		ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 		break;
 	}
 }
@@ -1333,20 +1263,16 @@ static void ccw_device_schedule_recovery(void)
 static int purge_fn(struct device *dev, void *data)
 {
 	struct ccw_device *cdev = to_ccwdev(dev);
-	struct ccw_device_private *priv = cdev->private;
-	int unreg;
+	struct ccw_dev_id *id = &cdev->private->dev_id;
 
 	spin_lock_irq(cdev->ccwlock);
-	unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
-		(priv->state == DEV_STATE_OFFLINE);
+	if (is_blacklisted(id->ssid, id->devno) &&
+	    (cdev->private->state == DEV_STATE_OFFLINE)) {
+		CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
+			      id->devno);
+		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
+	}
 	spin_unlock_irq(cdev->ccwlock);
-	if (!unreg)
-		goto out;
-	CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
-		      priv->dev_id.devno);
-	ccw_device_schedule_sch_unregister(cdev);
-
-out:
 	/* Abort loop in case of pending signal. */
 	if (signal_pending(current))
 		return -EINTR;
@@ -1456,12 +1382,14 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
 		goto out_unlock;
 	if (work_pending(&sch->todo_work))
 		goto out_unlock;
+	cdev = sch_get_cdev(sch);
+	if (cdev && work_pending(&cdev->private->todo_work))
+		goto out_unlock;
 	action = sch_get_action(sch);
 	CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
 		      sch->schid.ssid, sch->schid.sch_no, process,
 		      action);
 	/* Perform immediate actions while holding the lock. */
-	cdev = sch_get_cdev(sch);
 	switch (action) {
 	case IO_SCH_REPROBE:
 		/* Trigger device recognition. */
@@ -1753,7 +1681,7 @@ static int ccw_device_pm_prepare(struct device *dev)
 {
 	struct ccw_device *cdev = to_ccwdev(dev);
 
-	if (work_pending(&cdev->private->kick_work))
+	if (work_pending(&cdev->private->todo_work))
 		return -EAGAIN;
 	/* Fail while device is being set online/offline. */
 	if (atomic_read(&cdev->private->onoff))
@@ -1874,7 +1802,7 @@ static int resume_handle_boxed(struct ccw_device *cdev)
 	cdev->private->state = DEV_STATE_BOXED;
 	if (ccw_device_notify(cdev, CIO_BOXED))
 		return 0;
-	ccw_device_schedule_sch_unregister(cdev);
+	ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 	return -ENODEV;
 }
 
@@ -1883,7 +1811,7 @@ static int resume_handle_disc(struct ccw_device *cdev)
 	cdev->private->state = DEV_STATE_DISCONNECTED;
 	if (ccw_device_notify(cdev, CIO_GONE))
 		return 0;
-	ccw_device_schedule_sch_unregister(cdev);
+	ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 	return -ENODEV;
 }
 
@@ -1928,9 +1856,7 @@ static int ccw_device_pm_restore(struct device *dev)
 	/* check if the device type has changed */
 	if (!ccw_device_test_sense_data(cdev)) {
 		ccw_device_update_sense_data(cdev);
-		PREPARE_WORK(&cdev->private->kick_work,
-			     ccw_device_do_unbind_bind);
-		queue_work(ccw_device_work, &cdev->private->kick_work);
+		ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 		ret = -ENODEV;
 		goto out_unlock;
 	}
@@ -1974,7 +1900,7 @@ out_disc_unlock:
 	goto out_restore;
 
 out_unreg_unlock:
-	ccw_device_schedule_sch_unregister(cdev);
+	ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 	ret = -ENODEV;
 out_unlock:
 	spin_unlock_irq(sch->lock);
@@ -2039,6 +1965,77 @@ ccw_device_get_subchannel_id(struct ccw_device *cdev)
 	return sch->schid;
 }
 
+static void ccw_device_todo(struct work_struct *work)
+{
+	struct ccw_device_private *priv;
+	struct ccw_device *cdev;
+	struct subchannel *sch;
+	enum cdev_todo todo;
+
+	priv = container_of(work, struct ccw_device_private, todo_work);
+	cdev = priv->cdev;
+	sch = to_subchannel(cdev->dev.parent);
+	/* Find out todo. */
+	spin_lock_irq(cdev->ccwlock);
+	todo = priv->todo;
+	priv->todo = CDEV_TODO_NOTHING;
+	CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
+		      priv->dev_id.ssid, priv->dev_id.devno, todo);
+	spin_unlock_irq(cdev->ccwlock);
+	/* Perform todo. */
+	switch (todo) {
+	case CDEV_TODO_ENABLE_CMF:
+		cmf_reenable(cdev);
+		break;
+	case CDEV_TODO_REBIND:
+		ccw_device_do_unbind_bind(cdev);
+		break;
+	case CDEV_TODO_REGISTER:
+		io_subchannel_register(cdev);
+		break;
+	case CDEV_TODO_UNREG_EVAL:
+		if (!sch_is_pseudo_sch(sch))
+			css_schedule_eval(sch->schid);
+		/* fall-through */
+	case CDEV_TODO_UNREG:
+		if (sch_is_pseudo_sch(sch))
+			ccw_device_unregister(cdev);
+		else
+			ccw_device_call_sch_unregister(cdev);
+		break;
+	default:
+		break;
+	}
+	/* Release workqueue ref. */
+	put_device(&cdev->dev);
+}
+
+/**
+ * ccw_device_sched_todo - schedule ccw device operation
+ * @cdev: ccw device
+ * @todo: todo
+ *
+ * Schedule the operation identified by @todo to be performed on the slow path
+ * workqueue. Do nothing if another operation with higher priority is already
+ * scheduled. Needs to be called with ccwdev lock held.
+ */
+void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
+{
+	CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
+		      cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
+		      todo);
+	if (cdev->private->todo >= todo)
+		return;
+	cdev->private->todo = todo;
+	/* Get workqueue ref. */
+	if (!get_device(&cdev->dev))
+		return;
+	if (!queue_work(slow_path_wq, &cdev->private->todo_work)) {
+		/* Already queued, release workqueue ref. */
+		put_device(&cdev->dev);
+	}
+}
+
 MODULE_LICENSE("GPL");
 EXPORT_SYMBOL(ccw_device_set_online);
 EXPORT_SYMBOL(ccw_device_set_offline);
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 246c6482842..adaa27efc59 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -81,8 +81,6 @@ void io_subchannel_init_config(struct subchannel *sch);
 
 int ccw_device_cancel_halt_clear(struct ccw_device *);
 
-void ccw_device_do_unbind_bind(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 *);
@@ -92,6 +90,7 @@ void ccw_device_update_sense_data(struct ccw_device *);
 int ccw_device_test_sense_data(struct ccw_device *);
 void ccw_device_schedule_sch_unregister(struct ccw_device *);
 int ccw_purge_blacklisted(void);
+void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo);
 
 /* Function prototypes for device status and basic sense stuff. */
 void ccw_device_accumulate_irb(struct ccw_device *, struct irb *);
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index d1e05f44fb6..b163743bf58 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -289,9 +289,7 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
 			wake_up(&cdev->private->wait_q);
 		} else {
 			ccw_device_update_sense_data(cdev);
-			PREPARE_WORK(&cdev->private->kick_work,
-				     ccw_device_do_unbind_bind);
-			queue_work(ccw_device_work, &cdev->private->kick_work);
+			ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 		}
 		return;
 	case DEV_STATE_BOXED:
@@ -343,28 +341,16 @@ int ccw_device_notify(struct ccw_device *cdev, int event)
 	return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
 }
 
-static void cmf_reenable_delayed(struct work_struct *work)
-{
-	struct ccw_device_private *priv;
-	struct ccw_device *cdev;
-
-	priv = container_of(work, struct ccw_device_private, kick_work);
-	cdev = priv->cdev;
-	cmf_reenable(cdev);
-}
-
 static void ccw_device_oper_notify(struct ccw_device *cdev)
 {
 	if (ccw_device_notify(cdev, CIO_OPER)) {
 		/* Reenable channel measurements, if needed. */
-		PREPARE_WORK(&cdev->private->kick_work, cmf_reenable_delayed);
-		queue_work(ccw_device_work, &cdev->private->kick_work);
+		ccw_device_sched_todo(cdev, CDEV_TODO_ENABLE_CMF);
 		return;
 	}
 	/* Driver doesn't want device back. */
 	ccw_device_set_notoper(cdev);
-	PREPARE_WORK(&cdev->private->kick_work, ccw_device_do_unbind_bind);
-	queue_work(ccw_device_work, &cdev->private->kick_work);
+	ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
 }
 
 /*
@@ -392,14 +378,14 @@ ccw_device_done(struct ccw_device *cdev, int state)
 		CIO_MSG_EVENT(0, "Boxed device %04x on subchannel %04x\n",
 			      cdev->private->dev_id.devno, sch->schid.sch_no);
 		if (cdev->online && !ccw_device_notify(cdev, CIO_BOXED))
-			ccw_device_schedule_sch_unregister(cdev);
+			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 		cdev->private->flags.donotify = 0;
 		break;
 	case DEV_STATE_NOT_OPER:
 		CIO_MSG_EVENT(0, "Device %04x gone on subchannel %04x\n",
 			      cdev->private->dev_id.devno, sch->schid.sch_no);
 		if (!ccw_device_notify(cdev, CIO_GONE))
-			ccw_device_schedule_sch_unregister(cdev);
+			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 		else
 			ccw_device_set_disconnected(cdev);
 		cdev->private->flags.donotify = 0;
@@ -409,7 +395,7 @@ ccw_device_done(struct ccw_device *cdev, int state)
 			      "%04x\n", cdev->private->dev_id.devno,
 			      sch->schid.sch_no);
 		if (!ccw_device_notify(cdev, CIO_NO_PATH))
-			ccw_device_schedule_sch_unregister(cdev);
+			ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 		else
 			ccw_device_set_disconnected(cdev);
 		cdev->private->flags.donotify = 0;
@@ -751,7 +737,7 @@ static void ccw_device_generic_notoper(struct ccw_device *cdev,
 				       enum dev_event dev_event)
 {
 	if (!ccw_device_notify(cdev, CIO_GONE))
-		ccw_device_schedule_sch_unregister(cdev);
+		ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 	else
 		ccw_device_set_disconnected(cdev);
 }
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index 0b8f381bd20..b770e420213 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -82,6 +82,15 @@ struct senseid {
 	struct ciw ciw[MAX_CIWS];	/* variable # of CIWs */
 }  __attribute__ ((packed, aligned(4)));
 
+enum cdev_todo {
+	CDEV_TODO_NOTHING,
+	CDEV_TODO_ENABLE_CMF,
+	CDEV_TODO_REBIND,
+	CDEV_TODO_REGISTER,
+	CDEV_TODO_UNREG,
+	CDEV_TODO_UNREG_EVAL,
+};
+
 struct ccw_device_private {
 	struct ccw_device *cdev;
 	struct subchannel *sch;
@@ -115,7 +124,8 @@ struct ccw_device_private {
 	struct senseid senseid;	/* SenseID info */
 	struct pgid pgid[8];	/* path group IDs per chpid*/
 	struct ccw1 iccws[2];	/* ccws for SNID/SID/SPGID commands */
-	struct work_struct kick_work;
+	struct work_struct todo_work;
+	enum cdev_todo todo;
 	wait_queue_head_t wait_q;
 	struct timer_list timer;
 	void *cmb;			/* measurement information */
-- 
cgit v1.2.3-70-g09d2


From a7ae2c02f5ab7080646a4cc6c01065ae9decad54 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:20 +0100
Subject: [S390] cio: inform user when online/offline processing fails

Print a warning message in case a ccw device enters boxed or
not operational state during online/offline processing.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 167446785d1..ee345066768 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -7,6 +7,10 @@
  *		 Cornelia Huck (cornelia.huck@de.ibm.com)
  *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
  */
+
+#define KMSG_COMPONENT "cio"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
@@ -347,6 +351,14 @@ int ccw_device_set_offline(struct ccw_device *cdev)
 	spin_unlock_irq(cdev->ccwlock);
 	wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 		   cdev->private->state == DEV_STATE_DISCONNECTED));
+	/* Inform the user if set offline failed. */
+	if (cdev->private->state == DEV_STATE_BOXED) {
+		pr_warning("%s: The device entered boxed state while "
+			   "being set offline\n", dev_name(&cdev->dev));
+	} else if (cdev->private->state == DEV_STATE_NOT_OPER) {
+		pr_warning("%s: The device stopped operating while "
+			   "being set offline\n", dev_name(&cdev->dev));
+	}
 	/* Give up reference from ccw_device_set_online(). */
 	put_device(&cdev->dev);
 	return 0;
@@ -407,6 +419,16 @@ int ccw_device_set_online(struct ccw_device *cdev)
 	if ((cdev->private->state != DEV_STATE_ONLINE) &&
 	    (cdev->private->state != DEV_STATE_W4SENSE)) {
 		spin_unlock_irq(cdev->ccwlock);
+		/* Inform the user that set online failed. */
+		if (cdev->private->state == DEV_STATE_BOXED) {
+			pr_warning("%s: Setting the device online failed "
+				   "because it is boxed\n",
+				   dev_name(&cdev->dev));
+		} else if (cdev->private->state == DEV_STATE_NOT_OPER) {
+			pr_warning("%s: Setting the device online failed "
+				   "because it is not operational\n",
+				   dev_name(&cdev->dev));
+		}
 		/* Give up online reference since onlining failed. */
 		put_device(&cdev->dev);
 		return -ENODEV;
-- 
cgit v1.2.3-70-g09d2


From 736b5db895eb900c108fe9e9b1659c171481169e Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:21 +0100
Subject: [S390] cio: handle error during device recognition consistently

Remove the return code from ccw_device_recognition and handle
recognition errors through the existing callback
ccw_device_recog_done to reduce cleanup code duplication.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c     | 57 ++++++-------------------------------------
 drivers/s390/cio/device.h     |  2 +-
 drivers/s390/cio/device_fsm.c | 20 +++++----------
 3 files changed, 15 insertions(+), 64 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index ee345066768..7ad6bfb2e55 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -486,18 +486,9 @@ static int online_store_handle_offline(struct ccw_device *cdev)
 
 static int online_store_recog_and_online(struct ccw_device *cdev)
 {
-	int ret;
-
 	/* Do device recognition, if needed. */
 	if (cdev->private->state == DEV_STATE_BOXED) {
-		ret = ccw_device_recognition(cdev);
-		if (ret) {
-			CIO_MSG_EVENT(0, "Couldn't start recognition "
-				      "for device 0.%x.%04x (ret=%d)\n",
-				      cdev->private->dev_id.ssid,
-				      cdev->private->dev_id.devno, ret);
-			return ret;
-		}
+		ccw_device_recognition(cdev);
 		wait_event(cdev->private->wait_q,
 			   cdev->private->flags.recog_done);
 		if (cdev->private->state != DEV_STATE_OFFLINE)
@@ -746,7 +737,7 @@ 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 io_subchannel_recog(struct ccw_device *, struct subchannel *);
 
 static void sch_create_and_recog_new_device(struct subchannel *sch)
 {
@@ -760,16 +751,7 @@ static void sch_create_and_recog_new_device(struct subchannel *sch)
 		return;
 	}
 	/* Start recognition for the new ccw device. */
-	if (io_subchannel_recog(cdev, sch)) {
-		spin_lock_irq(sch->lock);
-		sch_set_cdev(sch, NULL);
-		spin_unlock_irq(sch->lock);
-		css_sch_device_unregister(sch);
-		/* Put reference from io_subchannel_create_ccwdev(). */
-		put_device(&sch->dev);
-		/* Give up initial reference. */
-		put_device(&cdev->dev);
-	}
+	io_subchannel_recog(cdev, sch);
 }
 
 /*
@@ -879,10 +861,8 @@ io_subchannel_recog_done(struct ccw_device *cdev)
 	}
 }
 
-static int
-io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
+static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 {
-	int rc;
 	struct ccw_device_private *priv;
 
 	cdev->ccwlock = sch->lock;
@@ -903,13 +883,8 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 	/* Start async. device sensing. */
 	spin_lock_irq(sch->lock);
 	sch_set_cdev(sch, cdev);
-	rc = ccw_device_recognition(cdev);
+	ccw_device_recognition(cdev);
 	spin_unlock_irq(sch->lock);
-	if (rc) {
-		if (atomic_dec_and_test(&ccw_device_init_count))
-			wake_up(&ccw_device_init_wq);
-	}
-	return rc;
 }
 
 static int ccw_device_move_to_sch(struct ccw_device *cdev,
@@ -1528,10 +1503,7 @@ static int ccw_device_console_enable(struct ccw_device *cdev,
 	sch->driver = &io_subchannel_driver;
 	/* Initialize the ccw_device structure. */
 	cdev->dev.parent= &sch->dev;
-	rc = io_subchannel_recog(cdev, sch);
-	if (rc)
-		return rc;
-
+	io_subchannel_recog(cdev, sch);
 	/* Now wait for the async. recognition to come to an end. */
 	spin_lock_irq(cdev->ccwlock);
 	while (!dev_fsm_final_state(cdev))
@@ -1547,7 +1519,7 @@ static int ccw_device_console_enable(struct ccw_device *cdev,
 	rc = 0;
 out_unlock:
 	spin_unlock_irq(cdev->ccwlock);
-	return 0;
+	return rc;
 }
 
 struct ccw_device *
@@ -1789,7 +1761,6 @@ static int ccw_device_pm_thaw(struct device *dev)
 static void __ccw_device_pm_restore(struct ccw_device *cdev)
 {
 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
-	int ret;
 
 	if (cio_is_console(sch->schid))
 		goto out;
@@ -1799,22 +1770,10 @@ static void __ccw_device_pm_restore(struct ccw_device *cdev)
 	 */
 	spin_lock_irq(sch->lock);
 	cdev->private->flags.resuming = 1;
-	ret = ccw_device_recognition(cdev);
+	ccw_device_recognition(cdev);
 	spin_unlock_irq(sch->lock);
-	if (ret) {
-		CIO_MSG_EVENT(0, "Couldn't start recognition for device "
-			      "0.%x.%04x (ret=%d)\n",
-			      cdev->private->dev_id.ssid,
-			      cdev->private->dev_id.devno, ret);
-		spin_lock_irq(sch->lock);
-		cdev->private->state = DEV_STATE_DISCONNECTED;
-		spin_unlock_irq(sch->lock);
-		/* notify driver after the resume cb */
-		goto out;
-	}
 	wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
 		   cdev->private->state == DEV_STATE_DISCONNECTED);
-
 out:
 	cdev->private->flags.resuming = 0;
 }
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index adaa27efc59..78662e05d31 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -83,7 +83,7 @@ int ccw_device_cancel_halt_clear(struct ccw_device *);
 
 int ccw_device_is_orphan(struct ccw_device *);
 
-int ccw_device_recognition(struct ccw_device *);
+void ccw_device_recognition(struct ccw_device *);
 int ccw_device_online(struct ccw_device *);
 int ccw_device_offline(struct ccw_device *);
 void ccw_device_update_sense_data(struct ccw_device *);
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index b163743bf58..83adb919648 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -498,20 +498,9 @@ ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 /*
  * Start device recognition.
  */
-int
-ccw_device_recognition(struct ccw_device *cdev)
+void ccw_device_recognition(struct ccw_device *cdev)
 {
-	struct subchannel *sch;
-	int ret;
-
-	sch = to_subchannel(cdev->dev.parent);
-	ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
-	if (ret != 0)
-		/* Couldn't enable the subchannel for i/o. Sick device. */
-		return ret;
-
-	/* After 60s the device recognition is considered to have failed. */
-	ccw_device_set_timeout(cdev, 60*HZ);
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
 
 	/*
 	 * We used to start here with a sense pgid to find out whether a device
@@ -523,8 +512,11 @@ ccw_device_recognition(struct ccw_device *cdev)
 	 */
 	cdev->private->flags.recog_done = 0;
 	cdev->private->state = DEV_STATE_SENSE_ID;
+	if (cio_enable_subchannel(sch, (u32) (addr_t) sch)) {
+		ccw_device_recog_done(cdev, DEV_STATE_NOT_OPER);
+		return;
+	}
 	ccw_device_sense_id_start(cdev);
-	return 0;
 }
 
 /*
-- 
cgit v1.2.3-70-g09d2


From 1f5bd3848bfc56de4c32ef6971a6a966776204bb Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:23 +0100
Subject: [S390] cio: ensure proper locking during device recognition

Device recognition needs to be started with the ccw device lock
held to prevent race conditions between I/O starting and interrupt
reception.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 7ad6bfb2e55..afa362ce9e8 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -488,7 +488,9 @@ static int online_store_recog_and_online(struct ccw_device *cdev)
 {
 	/* Do device recognition, if needed. */
 	if (cdev->private->state == DEV_STATE_BOXED) {
+		spin_lock_irq(cdev->ccwlock);
 		ccw_device_recognition(cdev);
+		spin_unlock_irq(cdev->ccwlock);
 		wait_event(cdev->private->wait_q,
 			   cdev->private->flags.recog_done);
 		if (cdev->private->state != DEV_STATE_OFFLINE)
-- 
cgit v1.2.3-70-g09d2


From 9679baaf85b6e4dc662160bbbca344287ea6580d Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:27 +0100
Subject: [S390] cio: use ccw request infrastructure for pgid

Use the newly introduced ccw request infrastructure to implement
pgid related operations: sense pgid, set pgid and disband pg.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c      |   3 -
 drivers/s390/cio/device.h      |   3 -
 drivers/s390/cio/device_fsm.c  | 100 +----
 drivers/s390/cio/device_pgid.c | 876 +++++++++++++++++------------------------
 drivers/s390/cio/io_sch.h      |   5 +-
 5 files changed, 383 insertions(+), 604 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index afa362ce9e8..6a9ac85065e 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -957,9 +957,6 @@ void io_subchannel_init_config(struct subchannel *sch)
 {
 	memset(&sch->config, 0, sizeof(sch->config));
 	sch->config.csense = 1;
-	/* Use subchannel mp mode when there is more than 1 installed CHPID. */
-	if ((sch->schib.pmcw.pim & (sch->schib.pmcw.pim - 1)) != 0)
-		sch->config.mp = 1;
 }
 
 static void io_subchannel_init_fields(struct subchannel *sch)
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 2815798c416..ac6f55b4b74 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -112,15 +112,12 @@ void ccw_device_sense_id_done(struct ccw_device *, int);
 
 /* Function prototypes for path grouping stuff. */
 void ccw_device_sense_pgid_start(struct ccw_device *);
-void ccw_device_sense_pgid_irq(struct ccw_device *, enum dev_event);
 void ccw_device_sense_pgid_done(struct ccw_device *, int);
 
 void ccw_device_verify_start(struct ccw_device *);
-void ccw_device_verify_irq(struct ccw_device *, enum dev_event);
 void ccw_device_verify_done(struct ccw_device *, int);
 
 void ccw_device_disband_start(struct ccw_device *);
-void ccw_device_disband_irq(struct ccw_device *, enum dev_event);
 void ccw_device_disband_done(struct ccw_device *, int);
 
 int ccw_device_call_handler(struct ccw_device *);
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 6247d07d395..c7439f5500f 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -394,58 +394,6 @@ ccw_device_done(struct ccw_device *cdev, int state)
 	wake_up(&cdev->private->wait_q);
 }
 
-static int cmp_pgid(struct pgid *p1, struct pgid *p2)
-{
-	char *c1;
-	char *c2;
-
-	c1 = (char *)p1;
-	c2 = (char *)p2;
-
-	return memcmp(c1 + 1, c2 + 1, sizeof(struct pgid) - 1);
-}
-
-static void __ccw_device_get_common_pgid(struct ccw_device *cdev)
-{
-	int i;
-	int last;
-
-	last = 0;
-	for (i = 0; i < 8; i++) {
-		if (cdev->private->pgid[i].inf.ps.state1 == SNID_STATE1_RESET)
-			/* No PGID yet */
-			continue;
-		if (cdev->private->pgid[last].inf.ps.state1 ==
-		    SNID_STATE1_RESET) {
-			/* First non-zero PGID */
-			last = i;
-			continue;
-		}
-		if (cmp_pgid(&cdev->private->pgid[i],
-			     &cdev->private->pgid[last]) == 0)
-			/* Non-conflicting PGIDs */
-			continue;
-
-		/* PGID mismatch, can't pathgroup. */
-		CIO_MSG_EVENT(0, "SNID - pgid mismatch for device "
-			      "0.%x.%04x, can't pathgroup\n",
-			      cdev->private->dev_id.ssid,
-			      cdev->private->dev_id.devno);
-		cdev->private->options.pgroup = 0;
-		return;
-	}
-	if (cdev->private->pgid[last].inf.ps.state1 ==
-	    SNID_STATE1_RESET)
-		/* No previous pgid found */
-		memcpy(&cdev->private->pgid[0],
-		       &channel_subsystems[0]->global_pgid,
-		       sizeof(struct pgid));
-	else
-		/* Use existing pgid */
-		memcpy(&cdev->private->pgid[0], &cdev->private->pgid[last],
-		       sizeof(struct pgid));
-}
-
 /*
  * Function called from device_pgid.c after sense path ground has completed.
  */
@@ -457,12 +405,8 @@ ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 	sch = to_subchannel(cdev->dev.parent);
 	switch (err) {
 	case -EOPNOTSUPP: /* path grouping not supported, use nop instead. */
-		cdev->private->options.pgroup = 0;
-		break;
 	case 0: /* success */
 	case -EACCES: /* partial success, some paths not operational */
-		/* Check if all pgids are equal or 0. */
-		__ccw_device_get_common_pgid(cdev);
 		break;
 	case -ETIME:		/* Sense path group id stopped by timeout. */
 	case -EUSERS:		/* device is reserved for someone else. */
@@ -474,7 +418,6 @@ ccw_device_sense_pgid_done(struct ccw_device *cdev, int err)
 	}
 	/* Start Path Group verification. */
 	cdev->private->state = DEV_STATE_VERIFY;
-	cdev->private->flags.doverify = 0;
 	ccw_device_verify_start(cdev);
 }
 
@@ -537,7 +480,6 @@ ccw_device_verify_done(struct ccw_device *cdev, int err)
 	sch->lpm = sch->vpm;
 	/* Repeat path verification? */
 	if (cdev->private->flags.doverify) {
-		cdev->private->flags.doverify = 0;
 		ccw_device_verify_start(cdev);
 		return;
 	}
@@ -602,7 +544,6 @@ ccw_device_online(struct ccw_device *cdev)
 	if (!cdev->private->options.pgroup) {
 		/* Start initial path verification. */
 		cdev->private->state = DEV_STATE_VERIFY;
-		cdev->private->flags.doverify = 0;
 		ccw_device_verify_start(cdev);
 		return 0;
 	}
@@ -624,7 +565,6 @@ ccw_device_disband_done(struct ccw_device *cdev, int err)
 		break;
 	default:
 		cdev->private->flags.donotify = 0;
-		dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
 		break;
 	}
@@ -672,27 +612,6 @@ ccw_device_offline(struct ccw_device *cdev)
 	return 0;
 }
 
-/*
- * Handle timeout in device online/offline process.
- */
-static void
-ccw_device_onoff_timeout(struct ccw_device *cdev, enum dev_event dev_event)
-{
-	int ret;
-
-	ret = ccw_device_cancel_halt_clear(cdev);
-	switch (ret) {
-	case 0:
-		ccw_device_done(cdev, DEV_STATE_BOXED);
-		break;
-	case -ENODEV:
-		ccw_device_done(cdev, DEV_STATE_NOT_OPER);
-		break;
-	default:
-		ccw_device_set_timeout(cdev, 3*HZ);
-	}
-}
-
 /*
  * Handle not operational event in non-special state.
  */
@@ -751,7 +670,6 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 	}
 	/* Device is idle, we can do the path verification. */
 	cdev->private->state = DEV_STATE_VERIFY;
-	cdev->private->flags.doverify = 0;
 	ccw_device_verify_start(cdev);
 }
 
@@ -1103,9 +1021,9 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
 	},
 	[DEV_STATE_SENSE_PGID] = {
-		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
-		[DEV_EVENT_INTERRUPT]	= ccw_device_sense_pgid_irq,
-		[DEV_EVENT_TIMEOUT]	= ccw_device_onoff_timeout,
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
 	},
 	[DEV_STATE_SENSE_ID] = {
@@ -1121,9 +1039,9 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
 		[DEV_EVENT_VERIFY]	= ccw_device_offline_verify,
 	},
 	[DEV_STATE_VERIFY] = {
-		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
-		[DEV_EVENT_INTERRUPT]	= ccw_device_verify_irq,
-		[DEV_EVENT_TIMEOUT]	= ccw_device_onoff_timeout,
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
 		[DEV_EVENT_VERIFY]	= ccw_device_delay_verify,
 	},
 	[DEV_STATE_ONLINE] = {
@@ -1139,9 +1057,9 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
 		[DEV_EVENT_VERIFY]	= ccw_device_online_verify,
 	},
 	[DEV_STATE_DISBAND_PGID] = {
-		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
-		[DEV_EVENT_INTERRUPT]	= ccw_device_disband_irq,
-		[DEV_EVENT_TIMEOUT]	= ccw_device_onoff_timeout,
+		[DEV_EVENT_NOTOPER]	= ccw_device_request_event,
+		[DEV_EVENT_INTERRUPT]	= ccw_device_request_event,
+		[DEV_EVENT_TIMEOUT]	= ccw_device_request_event,
 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
 	},
 	[DEV_STATE_BOXED] = {
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index cb27bd4cc23..ce493144b05 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -1,594 +1,460 @@
 /*
- * drivers/s390/cio/device_pgid.c
+ *  CCW device PGID and path verification I/O handling.
  *
- *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- *			 IBM Corporation
- *    Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
- *		 Martin Schwidefsky (schwidefsky@de.ibm.com)
- *
- * Path Group ID functions.
+ *    Copyright IBM Corp. 2002,2009
+ *    Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *		 Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
  */
 
-#include <linux/module.h>
-#include <linux/init.h>
-
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/bitops.h>
 #include <asm/ccwdev.h>
 #include <asm/cio.h>
-#include <asm/delay.h>
-#include <asm/lowcore.h>
 
 #include "cio.h"
 #include "cio_debug.h"
-#include "css.h"
 #include "device.h"
-#include "ioasm.h"
 #include "io_sch.h"
 
+#define PGID_RETRIES	5
+#define PGID_TIMEOUT	(10 * HZ)
+
 /*
- * Helper function called from interrupt context to decide whether an
- * operation should be tried again.
+ * Process path verification data and report result.
  */
-static int __ccw_device_should_retry(union scsw *scsw)
+static void verify_done(struct ccw_device *cdev, int rc)
 {
-	/* CC is only valid if start function bit is set. */
-	if ((scsw->cmd.fctl & SCSW_FCTL_START_FUNC) && scsw->cmd.cc == 1)
-		return 1;
-	/* No more activity. For sense and set PGID we stubbornly try again. */
-	if (!scsw->cmd.actl)
-		return 1;
-	return 0;
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_dev_id *id = &cdev->private->dev_id;
+	int mpath = !cdev->private->flags.pgid_single;
+	int pgroup = cdev->private->options.pgroup;
+
+	if (rc)
+		goto out;
+	/* Ensure consistent multipathing state at device and channel. */
+	if (sch->config.mp != mpath) {
+		sch->config.mp = mpath;
+		rc = cio_commit_config(sch);
+	}
+out:
+	CIO_MSG_EVENT(2, "vrfy: device 0.%x.%04x: rc=%d pgroup=%d mpath=%d "
+			 "vpm=%02x\n", id->ssid, id->devno, rc, pgroup, mpath,
+			 sch->vpm);
+	ccw_device_verify_done(cdev, rc);
 }
 
 /*
- * Start Sense Path Group ID helper function. Used in ccw_device_recog
- * and ccw_device_sense_pgid.
+ * Create channel program to perform a NOOP.
  */
-static int
-__ccw_device_sense_pgid_start(struct ccw_device *cdev)
+static void nop_build_cp(struct ccw_device *cdev)
 {
-	struct subchannel *sch;
-	struct ccw1 *ccw;
-	int ret;
-	int i;
-
-	sch = to_subchannel(cdev->dev.parent);
-	/* Return if we already checked on all paths. */
-	if (cdev->private->imask == 0)
-		return (sch->lpm == 0) ? -ENODEV : -EACCES;
-	i = 8 - ffs(cdev->private->imask);
-
-	/* Setup sense path group id channel program. */
-	ccw = cdev->private->iccws;
-	ccw->cmd_code = CCW_CMD_SENSE_PGID;
-	ccw->count = sizeof (struct pgid);
-	ccw->flags = CCW_FLAG_SLI;
-
-	/* Reset device status. */
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
-	/* Try on every path. */
-	ret = -ENODEV;
-	while (cdev->private->imask != 0) {
-		/* Try every path multiple times. */
-		ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
-		if (cdev->private->iretry > 0) {
-			cdev->private->iretry--;
-			/* Reset internal retry indication. */
-			cdev->private->flags.intretry = 0;
-			ret = cio_start (sch, cdev->private->iccws, 
-					 cdev->private->imask);
-			/* ret is 0, -EBUSY, -EACCES or -ENODEV */
-			if (ret != -EACCES)
-				return ret;
-			CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel "
-				      "0.%x.%04x, lpm %02X, became 'not "
-				      "operational'\n",
-				      cdev->private->dev_id.devno,
-				      sch->schid.ssid,
-				      sch->schid.sch_no, cdev->private->imask);
-
-		}
-		cdev->private->imask >>= 1;
-		cdev->private->iretry = 5;
-		i++;
-	}
-
-	return ret;
+	struct ccw_request *req = &cdev->private->req;
+	struct ccw1 *cp = cdev->private->iccws;
+
+	cp->cmd_code	= CCW_CMD_NOOP;
+	cp->cda		= 0;
+	cp->count	= 0;
+	cp->flags	= CCW_FLAG_SLI;
+	req->cp		= cp;
 }
 
-void
-ccw_device_sense_pgid_start(struct ccw_device *cdev)
+/*
+ * Perform NOOP on a single path.
+ */
+static void nop_do(struct ccw_device *cdev)
 {
-	int ret;
-
-	/* Set a timeout of 60s */
-	ccw_device_set_timeout(cdev, 60*HZ);
-
-	cdev->private->state = DEV_STATE_SENSE_PGID;
-	cdev->private->imask = 0x80;
-	cdev->private->iretry = 5;
-	memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
-	ret = __ccw_device_sense_pgid_start(cdev);
-	if (ret && ret != -EBUSY)
-		ccw_device_sense_pgid_done(cdev, ret);
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
+
+	/* Adjust lpm. */
+	req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam & sch->opm);
+	if (!req->lpm)
+		goto out_nopath;
+	nop_build_cp(cdev);
+	ccw_request_start(cdev);
+	return;
+
+out_nopath:
+	verify_done(cdev, sch->vpm ? 0 : -EACCES);
 }
 
 /*
- * Called from interrupt context to check if a valid answer
- * to Sense Path Group ID was received.
+ * Adjust NOOP I/O status.
  */
-static int
-__ccw_device_check_sense_pgid(struct ccw_device *cdev)
+static enum io_status nop_filter(struct ccw_device *cdev, void *data,
+				 struct irb *irb, enum io_status status)
 {
-	struct subchannel *sch;
-	struct irb *irb;
-	int i;
-
-	sch = to_subchannel(cdev->dev.parent);
-	irb = &cdev->private->irb;
-	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
-		/* Retry Sense PGID if requested. */
-		if (cdev->private->flags.intretry) {
-			cdev->private->flags.intretry = 0;
-			return -EAGAIN;
-		}
-		return -ETIME;
-	}
-	if (irb->esw.esw0.erw.cons &&
-	    (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
-		/*
-		 * If the device doesn't support the Sense Path Group ID
-		 *  command further retries wouldn't help ...
-		 */
-		return -EOPNOTSUPP;
-	}
-	if (irb->esw.esw0.erw.cons) {
-		CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
-			      "lpum %02X, cnt %02d, sns : "
-			      "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
-			      cdev->private->dev_id.ssid,
-			      cdev->private->dev_id.devno,
-			      irb->esw.esw0.sublog.lpum,
-			      irb->esw.esw0.erw.scnt,
-			      irb->ecw[0], irb->ecw[1],
-			      irb->ecw[2], irb->ecw[3],
-			      irb->ecw[4], irb->ecw[5],
-			      irb->ecw[6], irb->ecw[7]);
-		return -EAGAIN;
-	}
-	if (irb->scsw.cmd.cc == 3) {
-		u8 lpm;
-
-		lpm = to_io_private(sch)->orb.cmd.lpm;
-		CIO_MSG_EVENT(3, "SNID - Device %04x on Subchannel 0.%x.%04x,"
-			      " lpm %02X, became 'not operational'\n",
-			      cdev->private->dev_id.devno, sch->schid.ssid,
-			      sch->schid.sch_no, lpm);
-		return -EACCES;
-	}
-	i = 8 - ffs(cdev->private->imask);
-	if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
-		CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
-			      "is reserved by someone else\n",
-			      cdev->private->dev_id.devno, sch->schid.ssid,
-			      sch->schid.sch_no);
-		return -EUSERS;
-	}
-	return 0;
+	/* Only subchannel status might indicate a path error. */
+	if (status == IO_STATUS_ERROR && irb->scsw.cmd.cstat == 0)
+		return IO_DONE;
+	return status;
 }
 
 /*
- * Got interrupt for Sense Path Group ID.
+ * Process NOOP request result for a single path.
  */
-void
-ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
+static void nop_callback(struct ccw_device *cdev, void *data, int rc)
 {
-	struct subchannel *sch;
-	struct irb *irb;
-	int ret;
-
-	irb = (struct irb *) __LC_IRB;
-
-	if (irb->scsw.cmd.stctl ==
-	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-		if (__ccw_device_should_retry(&irb->scsw)) {
-			ret = __ccw_device_sense_pgid_start(cdev);
-			if (ret && ret != -EBUSY)
-				ccw_device_sense_pgid_done(cdev, ret);
-		}
-		return;
-	}
-	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
-		return;
-	sch = to_subchannel(cdev->dev.parent);
-	ret = __ccw_device_check_sense_pgid(cdev);
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
-	switch (ret) {
-	/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
-	case -EOPNOTSUPP:	/* Sense Path Group ID not supported */
-		ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
-		break;
-	case -ETIME:		/* Sense path group id stopped by timeout. */
-		ccw_device_sense_pgid_done(cdev, -ETIME);
-		break;
-	case -EACCES:		/* channel is not operational. */
-		sch->lpm &= ~cdev->private->imask;
-		/* Fall through. */
-	case 0:			/* Sense Path Group ID successful. */
-		cdev->private->imask >>= 1;
-		cdev->private->iretry = 5;
-		/* Fall through. */
-	case -EAGAIN:		/* Try again. */
-		ret = __ccw_device_sense_pgid_start(cdev);
-		if (ret != 0 && ret != -EBUSY)
-			ccw_device_sense_pgid_done(cdev, ret);
-		break;
-	case -EUSERS:		/* device is reserved for someone else. */
-		ccw_device_sense_pgid_done(cdev, -EUSERS);
-		break;
-	}
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
+
+	if (rc == 0)
+		sch->vpm |= req->lpm;
+	else if (rc != -EACCES)
+		goto err;
+	req->lpm >>= 1;
+	nop_do(cdev);
+	return;
+
+err:
+	verify_done(cdev, rc);
 }
 
 /*
- * Path Group ID helper function.
+ * Create channel program to perform SET PGID on a single path.
  */
-static int
-__ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
+static void spid_build_cp(struct ccw_device *cdev, u8 fn)
 {
-	struct subchannel *sch;
-	struct ccw1 *ccw;
-	int ret;
-
-	sch = to_subchannel(cdev->dev.parent);
-
-	/* Setup sense path group id channel program. */
-	cdev->private->pgid[0].inf.fc = func;
-	ccw = cdev->private->iccws;
-	if (cdev->private->flags.pgid_single)
-		cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
-	else
-		cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
-	ccw->cmd_code = CCW_CMD_SET_PGID;
-	ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
-	ccw->count = sizeof (struct pgid);
-	ccw->flags = CCW_FLAG_SLI;
-
-	/* Reset device status. */
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
-
-	/* Try multiple times. */
-	ret = -EACCES;
-	if (cdev->private->iretry > 0) {
-		cdev->private->iretry--;
-		/* Reset internal retry indication. */
-		cdev->private->flags.intretry = 0;
-		ret = cio_start (sch, cdev->private->iccws,
-				 cdev->private->imask);
-		/* We expect an interrupt in case of success or busy
-		 * indication. */
-		if ((ret == 0) || (ret == -EBUSY))
-			return ret;
-	}
-	/* PGID command failed on this path. */
-	CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel "
-		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
-		      cdev->private->dev_id.devno, sch->schid.ssid,
-		      sch->schid.sch_no, cdev->private->imask);
-	return ret;
+	struct ccw_request *req = &cdev->private->req;
+	struct ccw1 *cp = cdev->private->iccws;
+	int i = 8 - ffs(req->lpm);
+	struct pgid *pgid = &cdev->private->pgid[i];
+
+	pgid->inf.fc	= fn;
+	cp->cmd_code	= CCW_CMD_SET_PGID;
+	cp->cda		= (u32) (addr_t) pgid;
+	cp->count	= sizeof(*pgid);
+	cp->flags	= CCW_FLAG_SLI;
+	req->cp		= cp;
 }
 
 /*
- * Helper function to send a nop ccw down a path.
+ * Perform establish/resign SET PGID on a single path.
  */
-static int __ccw_device_do_nop(struct ccw_device *cdev)
+static void spid_do(struct ccw_device *cdev)
 {
-	struct subchannel *sch;
-	struct ccw1 *ccw;
-	int ret;
-
-	sch = to_subchannel(cdev->dev.parent);
-
-	/* Setup nop channel program. */
-	ccw = cdev->private->iccws;
-	ccw->cmd_code = CCW_CMD_NOOP;
-	ccw->cda = 0;
-	ccw->count = 0;
-	ccw->flags = CCW_FLAG_SLI;
-
-	/* Reset device status. */
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
-
-	/* Try multiple times. */
-	ret = -EACCES;
-	if (cdev->private->iretry > 0) {
-		cdev->private->iretry--;
-		/* Reset internal retry indication. */
-		cdev->private->flags.intretry = 0;
-		ret = cio_start (sch, cdev->private->iccws,
-				 cdev->private->imask);
-		/* We expect an interrupt in case of success or busy
-		 * indication. */
-		if ((ret == 0) || (ret == -EBUSY))
-			return ret;
-	}
-	/* nop command failed on this path. */
-	CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel "
-		      "0.%x.%04x, lpm %02X, became 'not operational'\n",
-		      cdev->private->dev_id.devno, sch->schid.ssid,
-		      sch->schid.sch_no, cdev->private->imask);
-	return ret;
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
+	u8 fn;
+
+	/* Adjust lpm if paths are not set in pam. */
+	req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam);
+	if (!req->lpm)
+		goto out_nopath;
+	/* Channel program setup. */
+	if (req->lpm & sch->opm)
+		fn = SPID_FUNC_ESTABLISH;
+	else
+		fn = SPID_FUNC_RESIGN;
+	if (!cdev->private->flags.pgid_single)
+		fn |= SPID_FUNC_MULTI_PATH;
+	spid_build_cp(cdev, fn);
+	ccw_request_start(cdev);
+	return;
+
+out_nopath:
+	verify_done(cdev, sch->vpm ? 0 : -EACCES);
 }
 
+static void verify_start(struct ccw_device *cdev);
 
 /*
- * Called from interrupt context to check if a valid answer
- * to Set Path Group ID was received.
+ * Process SET PGID request result for a single path.
  */
-static int
-__ccw_device_check_pgid(struct ccw_device *cdev)
+static void spid_callback(struct ccw_device *cdev, void *data, int rc)
 {
-	struct subchannel *sch;
-	struct irb *irb;
-
-	sch = to_subchannel(cdev->dev.parent);
-	irb = &cdev->private->irb;
-	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
-		/* Retry Set PGID if requested. */
-		if (cdev->private->flags.intretry) {
-			cdev->private->flags.intretry = 0;
-			return -EAGAIN;
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
+
+	switch (rc) {
+	case 0:
+		sch->vpm |= req->lpm & sch->opm;
+		break;
+	case -EACCES:
+		break;
+	case -EOPNOTSUPP:
+		if (!cdev->private->flags.pgid_single) {
+			/* Try without multipathing. */
+			cdev->private->flags.pgid_single = 1;
+			goto out_restart;
 		}
-		return -ETIME;
-	}
-	if (irb->esw.esw0.erw.cons) {
-		if (irb->ecw[0] & SNS0_CMD_REJECT)
-			return -EOPNOTSUPP;
-		/* Hmm, whatever happened, try again. */
-		CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
-			      "cnt %02d, "
-			      "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
-			      cdev->private->dev_id.ssid,
-			      cdev->private->dev_id.devno,
-			      irb->esw.esw0.erw.scnt,
-			      irb->ecw[0], irb->ecw[1],
-			      irb->ecw[2], irb->ecw[3],
-			      irb->ecw[4], irb->ecw[5],
-			      irb->ecw[6], irb->ecw[7]);
-		return -EAGAIN;
-	}
-	if (irb->scsw.cmd.cc == 3) {
-		CIO_MSG_EVENT(3, "SPID - Device %04x on Subchannel 0.%x.%04x,"
-			      " lpm %02X, became 'not operational'\n",
-			      cdev->private->dev_id.devno, sch->schid.ssid,
-			      sch->schid.sch_no, cdev->private->imask);
-		return -EACCES;
+		/* Try without pathgrouping. */
+		cdev->private->options.pgroup = 0;
+		goto out_restart;
+	default:
+		goto err;
 	}
-	return 0;
+	req->lpm >>= 1;
+	spid_do(cdev);
+	return;
+
+out_restart:
+	verify_start(cdev);
+	return;
+err:
+	verify_done(cdev, rc);
+}
+
+static int pgid_cmp(struct pgid *p1, struct pgid *p2)
+{
+	return memcmp((char *) p1 + 1, (char *) p2 + 1,
+		      sizeof(struct pgid) - 1);
 }
 
 /*
- * Called from interrupt context to check the path status after a nop has
- * been send.
+ * Determine pathgroup state from PGID data.
  */
-static int __ccw_device_check_nop(struct ccw_device *cdev)
+static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
+			 int *mismatch, int *reserved, int *reset)
 {
-	struct subchannel *sch;
-	struct irb *irb;
-
-	sch = to_subchannel(cdev->dev.parent);
-	irb = &cdev->private->irb;
-	if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) {
-		/* Retry NOP if requested. */
-		if (cdev->private->flags.intretry) {
-			cdev->private->flags.intretry = 0;
-			return -EAGAIN;
+	struct pgid *pgid = &cdev->private->pgid[0];
+	struct pgid *first = NULL;
+	int lpm;
+	int i;
+
+	*mismatch = 0;
+	*reserved = 0;
+	*reset = 0;
+	for (i = 0, lpm = 0x80; i < 8; i++, pgid++, lpm >>= 1) {
+		if ((cdev->private->pgid_valid_mask & lpm) == 0)
+			continue;
+		if (pgid->inf.ps.state2 == SNID_STATE2_RESVD_ELSE)
+			*reserved = 1;
+		if (pgid->inf.ps.state1 == SNID_STATE1_RESET) {
+			/* A PGID was reset. */
+			*reset = 1;
+			continue;
 		}
-		return -ETIME;
-	}
-	if (irb->scsw.cmd.cc == 3) {
-		CIO_MSG_EVENT(3, "NOP - Device %04x on Subchannel 0.%x.%04x,"
-			      " lpm %02X, became 'not operational'\n",
-			      cdev->private->dev_id.devno, sch->schid.ssid,
-			      sch->schid.sch_no, cdev->private->imask);
-		return -EACCES;
+		if (!first) {
+			first = pgid;
+			continue;
+		}
+		if (pgid_cmp(pgid, first) != 0)
+			*mismatch = 1;
 	}
-	return 0;
+	if (!first)
+		first = &channel_subsystems[0]->global_pgid;
+	*p = first;
 }
 
-static void
-__ccw_device_verify_start(struct ccw_device *cdev)
+static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid)
 {
-	struct subchannel *sch;
-	__u8 func;
-	int ret;
-
-	sch = to_subchannel(cdev->dev.parent);
-	/* Repeat for all paths. */
-	for (; cdev->private->imask; cdev->private->imask >>= 1,
-				     cdev->private->iretry = 5) {
-		if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
-			/* Path not available, try next. */
-			continue;
-		if (cdev->private->options.pgroup) {
-			if (sch->opm & cdev->private->imask)
-				func = SPID_FUNC_ESTABLISH;
-			else
-				func = SPID_FUNC_RESIGN;
-			ret = __ccw_device_do_pgid(cdev, func);
-		} else
-			ret = __ccw_device_do_nop(cdev);
-		/* We expect an interrupt in case of success or busy
-		 * indication. */
-		if (ret == 0 || ret == -EBUSY)
-			return;
-		/* Permanent path failure, try next. */
+	int i;
+
+	for (i = 0; i < 8; i++)
+		memcpy(&cdev->private->pgid[i], pgid, sizeof(struct pgid));
+}
+
+/*
+ * Process SENSE PGID data and report result.
+ */
+static void snid_done(struct ccw_device *cdev, int rc)
+{
+	struct ccw_dev_id *id = &cdev->private->dev_id;
+	struct pgid *pgid;
+	int mismatch = 0;
+	int reserved = 0;
+	int reset = 0;
+
+	if (rc)
+		goto out;
+	pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset);
+	if (!mismatch) {
+		pgid_fill(cdev, pgid);
+		cdev->private->flags.pgid_rdy = 1;
 	}
-	/* Done with all paths. */
-	ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -EACCES);
+	if (reserved)
+		rc = -EUSERS;
+out:
+	CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x mism=%d "
+		      "rsvd=%d reset=%d\n", id->ssid, id->devno, rc,
+		      cdev->private->pgid_valid_mask, mismatch, reserved,
+		      reset);
+	ccw_device_sense_pgid_done(cdev, rc);
 }
-		
+
 /*
- * Got interrupt for Set Path Group ID.
+ * Create channel program to perform a SENSE PGID on a single path.
  */
-void
-ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
+static void snid_build_cp(struct ccw_device *cdev)
 {
-	struct subchannel *sch;
-	struct irb *irb;
-	int ret;
+	struct ccw_request *req = &cdev->private->req;
+	struct ccw1 *cp = cdev->private->iccws;
+	int i = 8 - ffs(req->lpm);
+
+	/* Channel program setup. */
+	cp->cmd_code	= CCW_CMD_SENSE_PGID;
+	cp->cda		= (u32) (addr_t) &cdev->private->pgid[i];
+	cp->count	= sizeof(struct pgid);
+	cp->flags	= CCW_FLAG_SLI;
+	req->cp		= cp;
+}
 
-	irb = (struct irb *) __LC_IRB;
+/*
+ * Perform SENSE PGID on a single path.
+ */
+static void snid_do(struct ccw_device *cdev)
+{
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
+
+	/* Adjust lpm if paths are not set in pam. */
+	req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam);
+	if (!req->lpm)
+		goto out_nopath;
+	snid_build_cp(cdev);
+	ccw_request_start(cdev);
+	return;
+
+out_nopath:
+	snid_done(cdev, cdev->private->pgid_valid_mask ? 0 : -EACCES);
+}
 
-	if (irb->scsw.cmd.stctl ==
-	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-		if (__ccw_device_should_retry(&irb->scsw))
-			__ccw_device_verify_start(cdev);
-		return;
-	}
-	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
-		return;
-	sch = to_subchannel(cdev->dev.parent);
-	if (cdev->private->options.pgroup)
-		ret = __ccw_device_check_pgid(cdev);
-	else
-		ret = __ccw_device_check_nop(cdev);
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
+/*
+ * Process SENSE PGID request result for single path.
+ */
+static void snid_callback(struct ccw_device *cdev, void *data, int rc)
+{
+	struct ccw_request *req = &cdev->private->req;
+
+	if (rc == 0)
+		cdev->private->pgid_valid_mask |= req->lpm;
+	else if (rc != -EACCES)
+		goto err;
+	req->lpm >>= 1;
+	snid_do(cdev);
+	return;
+
+err:
+	snid_done(cdev, rc);
+}
 
-	switch (ret) {
-	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
-	case 0:
-		/* Path verification ccw finished successfully, update lpm. */
-		sch->vpm |= sch->opm & cdev->private->imask;
-		/* Go on with next path. */
-		cdev->private->imask >>= 1;
-		cdev->private->iretry = 5;
-		__ccw_device_verify_start(cdev);
-		break;
-	case -EOPNOTSUPP:
-		/*
-		 * One of those strange devices which claim to be able
-		 * to do multipathing but not for Set Path Group ID.
-		 */
-		if (cdev->private->flags.pgid_single)
-			cdev->private->options.pgroup = 0;
-		else
-			cdev->private->flags.pgid_single = 1;
-		/* Retry */
-		sch->vpm = 0;
-		cdev->private->imask = 0x80;
-		cdev->private->iretry = 5;
-		/* fall through. */
-	case -EAGAIN:		/* Try again. */
-		__ccw_device_verify_start(cdev);
-		break;
-	case -ETIME:		/* Set path group id stopped by timeout. */
-		ccw_device_verify_done(cdev, -ETIME);
-		break;
-	case -EACCES:		/* channel is not operational. */
-		cdev->private->imask >>= 1;
-		cdev->private->iretry = 5;
-		__ccw_device_verify_start(cdev);
-		break;
-	}
+/**
+ * ccw_device_sense_pgid_start - perform SENSE PGID
+ * @cdev: ccw device
+ *
+ * Execute a SENSE PGID channel program on each path to @cdev to update its
+ * PGID information. When finished, call ccw_device_sense_id_done with a
+ * return code specifying the result.
+ */
+void ccw_device_sense_pgid_start(struct ccw_device *cdev)
+{
+	struct ccw_request *req = &cdev->private->req;
+
+	CIO_TRACE_EVENT(4, "snid");
+	CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
+	/* Initialize PGID data. */
+	memset(cdev->private->pgid, 0, sizeof(cdev->private->pgid));
+	cdev->private->flags.pgid_rdy = 0;
+	cdev->private->pgid_valid_mask = 0;
+	/* Initialize request data. */
+	memset(req, 0, sizeof(*req));
+	req->timeout	= PGID_TIMEOUT;
+	req->maxretries	= PGID_RETRIES;
+	req->callback	= snid_callback;
+	req->lpm	= 0x80;
+	snid_do(cdev);
 }
 
-void
-ccw_device_verify_start(struct ccw_device *cdev)
+/*
+ * Perform path verification.
+ */
+static void verify_start(struct ccw_device *cdev)
 {
 	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
 
-	cdev->private->flags.pgid_single = 0;
-	cdev->private->imask = 0x80;
-	cdev->private->iretry = 5;
-
-	/* Start with empty vpm. */
 	sch->vpm = 0;
-
-	/* Get current pam. */
-	if (cio_update_schib(sch)) {
-		ccw_device_verify_done(cdev, -ENODEV);
-		return;
+	/* Initialize request data. */
+	memset(req, 0, sizeof(*req));
+	req->timeout	= PGID_TIMEOUT;
+	req->maxretries	= PGID_RETRIES;
+	req->lpm	= 0x80;
+	if (cdev->private->options.pgroup) {
+		req->callback	= spid_callback;
+		spid_do(cdev);
+	} else {
+		req->filter	= nop_filter;
+		req->callback	= nop_callback;
+		nop_do(cdev);
 	}
-	/* After 60s path verification is considered to have failed. */
-	ccw_device_set_timeout(cdev, 60*HZ);
-	__ccw_device_verify_start(cdev);
 }
 
-static void
-__ccw_device_disband_start(struct ccw_device *cdev)
+/**
+ * ccw_device_verify_start - perform path verification
+ * @cdev: ccw device
+ *
+ * Perform an I/O on each available channel path to @cdev to determine which
+ * paths are operational. The resulting path mask is stored in sch->vpm.
+ * If device options specify pathgrouping, establish a pathgroup for the
+ * operational paths. When finished, call ccw_device_verify_done with a
+ * return code specifying the result.
+ */
+void ccw_device_verify_start(struct ccw_device *cdev)
 {
-	struct subchannel *sch;
-	int ret;
-
-	sch = to_subchannel(cdev->dev.parent);
-	while (cdev->private->imask != 0) {
-		if (sch->lpm & cdev->private->imask) {
-			ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
-			if (ret == 0)
-				return;
-		}
-		cdev->private->iretry = 5;
-		cdev->private->imask >>= 1;
-	}
-	ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
+	CIO_TRACE_EVENT(4, "vrfy");
+	CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
+	if (!cdev->private->flags.pgid_rdy) {
+		/* No pathgrouping possible. */
+		cdev->private->options.pgroup = 0;
+		cdev->private->flags.pgid_single = 1;
+	} else
+		cdev->private->flags.pgid_single = 0;
+	cdev->private->flags.doverify = 0;
+	verify_start(cdev);
 }
 
 /*
- * Got interrupt for Unset Path Group ID.
+ * Process disband SET PGID request result.
  */
-void
-ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
+static void disband_callback(struct ccw_device *cdev, void *data, int rc)
 {
-	struct subchannel *sch;
-	struct irb *irb;
-	int ret;
-
-	irb = (struct irb *) __LC_IRB;
-
-	if (irb->scsw.cmd.stctl ==
-	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
-		if (__ccw_device_should_retry(&irb->scsw))
-			__ccw_device_disband_start(cdev);
-		return;
-	}
-	if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
-		return;
-	sch = to_subchannel(cdev->dev.parent);
-	ret = __ccw_device_check_pgid(cdev);
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
-	switch (ret) {
-	/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
-	case 0:			/* disband successful. */
-		ccw_device_disband_done(cdev, ret);
-		break;
-	case -EOPNOTSUPP:
-		/*
-		 * One of those strange devices which claim to be able
-		 * to do multipathing but not for Unset Path Group ID.
-		 */
-		cdev->private->flags.pgid_single = 1;
-		/* fall through. */
-	case -EAGAIN:		/* Try again. */
-		__ccw_device_disband_start(cdev);
-		break;
-	case -ETIME:		/* Set path group id stopped by timeout. */
-		ccw_device_disband_done(cdev, -ETIME);
-		break;
-	case -EACCES:		/* channel is not operational. */
-		cdev->private->imask >>= 1;
-		cdev->private->iretry = 5;
-		__ccw_device_disband_start(cdev);
-		break;
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_dev_id *id = &cdev->private->dev_id;
+
+	if (rc)
+		goto out;
+	/* Ensure consistent multipathing state at device and channel. */
+	cdev->private->flags.pgid_single = 1;
+	if (sch->config.mp) {
+		sch->config.mp = 0;
+		rc = cio_commit_config(sch);
 	}
+out:
+	CIO_MSG_EVENT(0, "disb: device 0.%x.%04x: rc=%d\n", id->ssid, id->devno,
+		      rc);
+	ccw_device_disband_done(cdev, rc);
 }
 
-void
-ccw_device_disband_start(struct ccw_device *cdev)
+/**
+ * ccw_device_disband_start - disband pathgroup
+ * @cdev: ccw device
+ *
+ * Execute a SET PGID channel program on @cdev to disband a previously
+ * established pathgroup. When finished, call ccw_device_disband_done with
+ * a return code specifying the result.
+ */
+void ccw_device_disband_start(struct ccw_device *cdev)
 {
-	/* After 60s disbanding is considered to have failed. */
-	ccw_device_set_timeout(cdev, 60*HZ);
-
-	cdev->private->flags.pgid_single = 0;
-	cdev->private->iretry = 5;
-	cdev->private->imask = 0x80;
-	__ccw_device_disband_start(cdev);
+	struct subchannel *sch = to_subchannel(cdev->dev.parent);
+	struct ccw_request *req = &cdev->private->req;
+	u8 fn;
+
+	CIO_TRACE_EVENT(4, "disb");
+	CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
+	/* Request setup. */
+	memset(req, 0, sizeof(*req));
+	req->timeout	= PGID_TIMEOUT;
+	req->maxretries	= PGID_RETRIES;
+	req->lpm	= sch->schib.pmcw.pam & sch->opm;
+	req->callback	= disband_callback;
+	fn = SPID_FUNC_DISBAND;
+	if (!cdev->private->flags.pgid_single)
+		fn |= SPID_FUNC_MULTI_PATH;
+	spid_build_cp(cdev, fn);
+	ccw_request_start(cdev);
 }
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index f9ff7683e24..78b5ad980cf 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -149,8 +149,8 @@ struct ccw_device_private {
 	struct ccw_dev_id dev_id;	/* device id */
 	struct subchannel_id schid;	/* subchannel number */
 	struct ccw_request req;		/* internal I/O request */
-	u8 imask;		/* lpm mask for SNID/SID/SPGID */
-	int iretry;		/* retry counter SNID/SID/SPGID */
+	int iretry;
+	u8 pgid_valid_mask;		/* mask of valid PGIDs */
 	struct {
 		unsigned int fast:1;	/* post with "channel end" */
 		unsigned int repall:1;	/* report every interrupt status */
@@ -167,6 +167,7 @@ struct ccw_device_private {
 		unsigned int fake_irb:1;    /* deliver faked irb */
 		unsigned int intretry:1;    /* retry internal operation */
 		unsigned int resuming:1;    /* recognition while resume */
+		unsigned int pgid_rdy:1;    /* pgids are ready */
 	} __attribute__((packed)) flags;
 	unsigned long intparm;	/* user interruption parameter */
 	struct qdio_irq *qdio_data;
-- 
cgit v1.2.3-70-g09d2


From 350e91207bc9c6a464c22b9e0e30d21dfc07efe3 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:28 +0100
Subject: [S390] cio: allow setting not-operational devices offline

Accept a request for setting a not-operational device offline.
This way, users can remove devices from Linux which would otherwise
remain unusable until reboot.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 6a9ac85065e..9af864f615b 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -529,11 +529,10 @@ static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 	int force, ret;
 	unsigned long i;
 
-	if ((cdev->private->state != DEV_STATE_OFFLINE &&
-	     cdev->private->state != DEV_STATE_ONLINE &&
-	     cdev->private->state != DEV_STATE_BOXED &&
-	     cdev->private->state != DEV_STATE_DISCONNECTED) ||
-	    atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
+	if (!dev_fsm_final_state(cdev) &&
+	    cdev->private->state != DEV_STATE_DISCONNECTED)
+		return -EAGAIN;
+	if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 		return -EAGAIN;
 
 	if (cdev->drv && !try_module_get(cdev->drv->owner)) {
-- 
cgit v1.2.3-70-g09d2


From 4257aaecffab77bad43e12057f56a5590b360f9f Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Date: Mon, 7 Dec 2009 12:51:29 +0100
Subject: [S390] cio: remove intretry flag

After changing all internal I/O functions to use the newly introduced
ccw request infrastructure, retries are handled automatically after a
clear operation. Therefore remove the internal retry flag and
associated code.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c        | 58 ++++++++++++----------------------------
 drivers/s390/cio/device.h        |  1 -
 drivers/s390/cio/device_fsm.c    | 27 -------------------
 drivers/s390/cio/device_ops.c    |  3 +--
 drivers/s390/cio/device_status.c |  3 ---
 drivers/s390/cio/io_sch.h        |  1 -
 6 files changed, 18 insertions(+), 75 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 9af864f615b..e24b9b1d102 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1068,36 +1068,6 @@ static void io_subchannel_verify(struct subchannel *sch)
 		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
 }
 
-static int check_for_io_on_path(struct subchannel *sch, int mask)
-{
-	if (cio_update_schib(sch))
-		return 0;
-	if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
-		return 1;
-	return 0;
-}
-
-static void terminate_internal_io(struct subchannel *sch,
-				  struct ccw_device *cdev)
-{
-	if (cio_clear(sch)) {
-		/* Recheck device in case clear failed. */
-		sch->lpm = 0;
-		if (cdev->online)
-			dev_fsm_event(cdev, DEV_EVENT_VERIFY);
-		else
-			css_schedule_eval(sch->schid);
-		return;
-	}
-	cdev->private->state = DEV_STATE_CLEAR_VERIFY;
-	/* Request retry of internal operation. */
-	cdev->private->flags.intretry = 1;
-	/* Call handler. */
-	if (cdev->handler)
-		cdev->handler(cdev, cdev->private->intparm,
-			      ERR_PTR(-EIO));
-}
-
 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
 {
 	struct ccw_device *cdev;
@@ -1105,18 +1075,24 @@ static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
 	cdev = sch_get_cdev(sch);
 	if (!cdev)
 		return;
-	if (check_for_io_on_path(sch, mask)) {
-		if (cdev->private->state == DEV_STATE_ONLINE)
-			ccw_device_kill_io(cdev);
-		else {
-			terminate_internal_io(sch, cdev);
-			/* Re-start path verification. */
-			dev_fsm_event(cdev, DEV_EVENT_VERIFY);
-		}
-	} else
-		/* trigger path verification. */
-		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+	if (cio_update_schib(sch))
+		goto err;
+	/* Check for I/O on path. */
+	if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
+		goto out;
+	if (cdev->private->state == DEV_STATE_ONLINE) {
+		ccw_device_kill_io(cdev);
+		goto out;
+	}
+	if (cio_clear(sch))
+		goto err;
+out:
+	/* Trigger path verification. */
+	dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+	return;
 
+err:
+	dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 }
 
 static int io_subchannel_chp_event(struct subchannel *sch,
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index ac6f55b4b74..4e1775cf973 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -21,7 +21,6 @@ enum dev_state {
 	DEV_STATE_DISBAND_PGID,
 	DEV_STATE_BOXED,
 	/* states to wait for i/o completion before doing something */
-	DEV_STATE_CLEAR_VERIFY,
 	DEV_STATE_TIMEOUT_KILL,
 	DEV_STATE_QUIESCE,
 	/* special states for devices gone not operational */
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index c7439f5500f..349d8c52c0d 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -771,12 +771,6 @@ ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 	 */
 	if (scsw_fctl(&irb->scsw) &
 	    (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC)) {
-		/* Retry Basic Sense if requested. */
-		if (cdev->private->flags.intretry) {
-			cdev->private->flags.intretry = 0;
-			ccw_device_do_sense(cdev, irb);
-			return;
-		}
 		cdev->private->flags.dosense = 0;
 		memset(&cdev->private->irb, 0, sizeof(struct irb));
 		ccw_device_accumulate_irb(cdev, irb);
@@ -799,21 +793,6 @@ call_handler:
 		ccw_device_online_verify(cdev, 0);
 }
 
-static void
-ccw_device_clear_verify(struct ccw_device *cdev, enum dev_event dev_event)
-{
-	struct irb *irb;
-
-	irb = (struct irb *) __LC_IRB;
-	/* Accumulate status. We don't do basic sense. */
-	ccw_device_accumulate_irb(cdev, irb);
-	/* Remember to clear irb to avoid residuals. */
-	memset(&cdev->private->irb, 0, sizeof(struct irb));
-	/* Try to start delayed device verification. */
-	ccw_device_online_verify(cdev, 0);
-	/* Note: Don't call handler for cio initiated clear! */
-}
-
 static void
 ccw_device_killing_irq(struct ccw_device *cdev, enum dev_event dev_event)
 {
@@ -1069,12 +1048,6 @@ fsm_func_t *dev_jumptable[NR_DEV_STATES][NR_DEV_EVENTS] = {
 		[DEV_EVENT_VERIFY]	= ccw_device_nop,
 	},
 	/* states to wait for i/o completion before doing something */
-	[DEV_STATE_CLEAR_VERIFY] = {
-		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
-		[DEV_EVENT_INTERRUPT]   = ccw_device_clear_verify,
-		[DEV_EVENT_TIMEOUT]	= ccw_device_nop,
-		[DEV_EVENT_VERIFY]	= ccw_device_nop,
-	},
 	[DEV_STATE_TIMEOUT_KILL] = {
 		[DEV_EVENT_NOTOPER]	= ccw_device_generic_notoper,
 		[DEV_EVENT_INTERRUPT]	= ccw_device_killing_irq,
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index 2d0efee8a29..5ab90ec4231 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -167,8 +167,7 @@ int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
 		return -EINVAL;
 	if (cdev->private->state == DEV_STATE_NOT_OPER)
 		return -ENODEV;
-	if (cdev->private->state == DEV_STATE_VERIFY ||
-	    cdev->private->state == DEV_STATE_CLEAR_VERIFY) {
+	if (cdev->private->state == DEV_STATE_VERIFY) {
 		/* Remember to fake irb when finished. */
 		if (!cdev->private->flags.fake_irb) {
 			cdev->private->flags.fake_irb = 1;
diff --git a/drivers/s390/cio/device_status.c b/drivers/s390/cio/device_status.c
index 5814dbee241..66d8066ef22 100644
--- a/drivers/s390/cio/device_status.c
+++ b/drivers/s390/cio/device_status.c
@@ -336,9 +336,6 @@ ccw_device_do_sense(struct ccw_device *cdev, struct irb *irb)
 	sense_ccw->count = SENSE_MAX_COUNT;
 	sense_ccw->flags = CCW_FLAG_SLI;
 
-	/* Reset internal retry indication. */
-	cdev->private->flags.intretry = 0;
-
 	rc = cio_start(sch, sense_ccw, 0xff);
 	if (rc == -ENODEV || rc == -EACCES)
 		dev_fsm_event(cdev, DEV_EVENT_VERIFY);
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index 78b5ad980cf..8942dc092d0 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -165,7 +165,6 @@ struct ccw_device_private {
 		unsigned int donotify:1;    /* call notify function */
 		unsigned int recog_done:1;  /* dev. recog. complete */
 		unsigned int fake_irb:1;    /* deliver faked irb */
-		unsigned int intretry:1;    /* retry internal operation */
 		unsigned int resuming:1;    /* recognition while resume */
 		unsigned int pgid_rdy:1;    /* pgids are ready */
 	} __attribute__((packed)) flags;
-- 
cgit v1.2.3-70-g09d2


From 7d253b9a1aaf5192808e641659f4feb122faa536 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:33 +0100
Subject: [S390] cio: remove registered flag from ccw_device_private

We used to maintain a "registered" flag in our ccw_device_private
structure. This patch removes the "registered" flag and converts
all users of it to device_is_registered which has the exact same
meaning.

Note: The usage the atomic operation test_and_clear_bit is replaced
by the non-atomic if (device_is_registered()) device_del(). This
will not do harm, since we serialize calls to ccw_device_unregister
with a single-threaded workqueue.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 11 +++--------
 drivers/s390/cio/io_sch.h |  1 -
 2 files changed, 3 insertions(+), 9 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index e24b9b1d102..f4401ede768 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -303,7 +303,7 @@ int ccw_device_is_orphan(struct ccw_device *cdev)
 
 static void ccw_device_unregister(struct ccw_device *cdev)
 {
-	if (test_and_clear_bit(1, &cdev->private->registered)) {
+	if (device_is_registered(&cdev->dev)) {
 		device_del(&cdev->dev);
 		/* Release reference from device_initialize(). */
 		put_device(&cdev->dev);
@@ -640,12 +640,7 @@ static int ccw_device_register(struct ccw_device *cdev)
 			   cdev->private->dev_id.devno);
 	if (ret)
 		return ret;
-	ret = device_add(dev);
-	if (ret)
-		return ret;
-
-	set_bit(1, &cdev->private->registered);
-	return ret;
+	return device_add(dev);
 }
 
 static int match_dev_id(struct device *dev, void *data)
@@ -669,7 +664,7 @@ static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 {
 	int ret;
 
-	if (test_bit(1, &cdev->private->registered)) {
+	if (device_is_registered(&cdev->dev)) {
 		device_release_driver(&cdev->dev);
 		ret = device_attach(&cdev->dev);
 		WARN_ON(ret == -ENODEV);
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index 0559479073c..ca1063d6b50 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -145,7 +145,6 @@ struct ccw_device_private {
 	struct subchannel *sch;
 	int state;		/* device state */
 	atomic_t onoff;
-	unsigned long registered;
 	struct ccw_dev_id dev_id;	/* device id */
 	struct subchannel_id schid;	/* subchannel number */
 	struct ccw_request req;		/* internal I/O request */
-- 
cgit v1.2.3-70-g09d2


From 24a1872d6411c7cce82c0888a4fbea23e993e051 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:34 +0100
Subject: [S390] cio: add per device initialization status flag

The function ccw_device_unregister has to ensure to remove
all references obtained by device_add and device_initialize.
Unfortunately it gets called for devices which are
1) uninitialized, 2) initialized but unregistered, and
3) registered devices. To distinguish 1) and 2) this patch
introduces a new flag "initialized", which is 1 as long as we
hold the initial device reference.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 6 ++++++
 drivers/s390/cio/io_sch.h | 1 +
 2 files changed, 7 insertions(+)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index f4401ede768..e8cb99a63cc 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -304,7 +304,11 @@ int ccw_device_is_orphan(struct ccw_device *cdev)
 static void ccw_device_unregister(struct ccw_device *cdev)
 {
 	if (device_is_registered(&cdev->dev)) {
+		/* Undo device_add(). */
 		device_del(&cdev->dev);
+	}
+	if (cdev->private->flags.initialized) {
+		cdev->private->flags.initialized = 0;
 		/* Release reference from device_initialize(). */
 		put_device(&cdev->dev);
 	}
@@ -716,6 +720,7 @@ static int io_subchannel_initialize_dev(struct subchannel *sch,
 		put_device(&cdev->dev);
 		return -ENODEV;
 	}
+	cdev->private->flags.initialized = 1;
 	return 0;
 }
 
@@ -998,6 +1003,7 @@ static int io_subchannel_probe(struct subchannel *sch)
 		cdev = sch_get_cdev(sch);
 		cdev->dev.groups = ccwdev_attr_groups;
 		device_initialize(&cdev->dev);
+		cdev->private->flags.initialized = 1;
 		ccw_device_register(cdev);
 		/*
 		 * Check if the device is already online. If it is
diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h
index ca1063d6b50..dbc69a5a043 100644
--- a/drivers/s390/cio/io_sch.h
+++ b/drivers/s390/cio/io_sch.h
@@ -167,6 +167,7 @@ struct ccw_device_private {
 		unsigned int resuming:1;    /* recognition while resume */
 		unsigned int pgroup:1;	    /* pathgroup is set up */
 		unsigned int mpath:1;	    /* multipathing is set up */
+		unsigned int initialized:1; /* set if initial reference held */
 	} __attribute__((packed)) flags;
 	unsigned long intparm;	/* user interruption parameter */
 	struct qdio_irq *qdio_data;
-- 
cgit v1.2.3-70-g09d2


From 56e6b796fe9b99287648fc5686aae00106b37bab Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:35 +0100
Subject: [S390] cio: fix quiesce state

DEV_STATE_QUIESCE is used to stop all IO on a busy subchannel.
This patch fixes the following problems related to the QUIESCE
state:

* Fix a potential race condition which could occur when the
resulting state was DEV_STATE_OFFLINE.

* Add missing locking around cio_disable_subchannel,
ccw_device_cancel_halt_clear and the cdev's handler.

* Loop until we know for sure that the subchannel is disabled.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c     | 35 +++++++++++++++++++----------------
 drivers/s390/cio/device_fsm.c | 17 ++++-------------
 2 files changed, 23 insertions(+), 29 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index e8cb99a63cc..2b50f93b7fe 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1130,33 +1130,36 @@ static int io_subchannel_chp_event(struct subchannel *sch,
 	return 0;
 }
 
-static void
-io_subchannel_shutdown(struct subchannel *sch)
+static void io_subchannel_shutdown(struct subchannel *sch)
 {
 	struct ccw_device *cdev;
 	int ret;
 
+	spin_lock_irq(sch->lock);
 	cdev = sch_get_cdev(sch);
-
 	if (cio_is_console(sch->schid))
-		return;
+		goto out_unlock;
 	if (!sch->schib.pmcw.ena)
-		/* Nothing to do. */
-		return;
+		goto out_unlock;
 	ret = cio_disable_subchannel(sch);
 	if (ret != -EBUSY)
-		/* Subchannel is disabled, we're done. */
-		return;
-	cdev->private->state = DEV_STATE_QUIESCE;
+		goto out_unlock;
 	if (cdev->handler)
-		cdev->handler(cdev, cdev->private->intparm,
-			      ERR_PTR(-EIO));
-	ret = ccw_device_cancel_halt_clear(cdev);
-	if (ret == -EBUSY) {
-		ccw_device_set_timeout(cdev, HZ/10);
-		wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
+		cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
+	while (ret == -EBUSY) {
+		cdev->private->state = DEV_STATE_QUIESCE;
+		ret = ccw_device_cancel_halt_clear(cdev);
+		if (ret == -EBUSY) {
+			ccw_device_set_timeout(cdev, HZ/10);
+			spin_unlock_irq(sch->lock);
+			wait_event(cdev->private->wait_q,
+				   cdev->private->state != DEV_STATE_QUIESCE);
+			spin_lock_irq(sch->lock);
+		}
+		ret = cio_disable_subchannel(sch);
 	}
-	cio_disable_subchannel(sch);
+out_unlock:
+	spin_unlock_irq(sch->lock);
 }
 
 static int device_is_disconnected(struct ccw_device *cdev)
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 7d42417bc2c..862b89ef3ee 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -911,10 +911,7 @@ static void
 ccw_device_quiesce_done(struct ccw_device *cdev, enum dev_event dev_event)
 {
 	ccw_device_set_timeout(cdev, 0);
-	if (dev_event == DEV_EVENT_NOTOPER)
-		cdev->private->state = DEV_STATE_NOT_OPER;
-	else
-		cdev->private->state = DEV_STATE_OFFLINE;
+	cdev->private->state = DEV_STATE_NOT_OPER;
 	wake_up(&cdev->private->wait_q);
 }
 
@@ -924,17 +921,11 @@ ccw_device_quiesce_timeout(struct ccw_device *cdev, enum dev_event dev_event)
 	int ret;
 
 	ret = ccw_device_cancel_halt_clear(cdev);
-	switch (ret) {
-	case 0:
-		cdev->private->state = DEV_STATE_OFFLINE;
-		wake_up(&cdev->private->wait_q);
-		break;
-	case -ENODEV:
+	if (ret == -EBUSY) {
+		ccw_device_set_timeout(cdev, HZ/10);
+	} else {
 		cdev->private->state = DEV_STATE_NOT_OPER;
 		wake_up(&cdev->private->wait_q);
-		break;
-	default:
-		ccw_device_set_timeout(cdev, HZ/10);
 	}
 }
 
-- 
cgit v1.2.3-70-g09d2


From 0c609fca243d456af014e92ad1caca045072dfe8 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:37 +0100
Subject: [S390] cio: handle busy subchannel in ccw_device_move_to_sch

Try to disable the old subchannel before we ask the driver core
to move the attached device to a new parent. This way we can use
the QUIESCE state during shutdown which prevents a possible use
after free situation in some error cases.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 2b50f93b7fe..af500aac24e 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -892,12 +892,27 @@ static int ccw_device_move_to_sch(struct ccw_device *cdev,
 				  struct subchannel *sch)
 {
 	struct subchannel *old_sch;
-	int rc;
+	int rc, old_enabled = 0;
 
 	old_sch = to_subchannel(cdev->dev.parent);
 	/* Obtain child reference for new parent. */
 	if (!get_device(&sch->dev))
 		return -ENODEV;
+
+	if (!sch_is_pseudo_sch(old_sch)) {
+		spin_lock_irq(old_sch->lock);
+		old_enabled = old_sch->schib.pmcw.ena;
+		rc = 0;
+		if (old_enabled)
+			rc = cio_disable_subchannel(old_sch);
+		spin_unlock_irq(old_sch->lock);
+		if (rc == -EBUSY) {
+			/* Release child reference for new parent. */
+			put_device(&sch->dev);
+			return rc;
+		}
+	}
+
 	mutex_lock(&sch->reg_mutex);
 	rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 	mutex_unlock(&sch->reg_mutex);
@@ -906,6 +921,12 @@ static int ccw_device_move_to_sch(struct ccw_device *cdev,
 			      cdev->private->dev_id.ssid,
 			      cdev->private->dev_id.devno, sch->schid.ssid,
 			      sch->schib.pmcw.dev, rc);
+		if (old_enabled) {
+			/* Try to reenable the old subchannel. */
+			spin_lock_irq(old_sch->lock);
+			cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
+			spin_unlock_irq(old_sch->lock);
+		}
 		/* Release child reference for new parent. */
 		put_device(&sch->dev);
 		return rc;
@@ -914,7 +935,6 @@ static int ccw_device_move_to_sch(struct ccw_device *cdev,
 	if (!sch_is_pseudo_sch(old_sch)) {
 		spin_lock_irq(old_sch->lock);
 		sch_set_cdev(old_sch, NULL);
-		cio_disable_subchannel(old_sch);
 		spin_unlock_irq(old_sch->lock);
 		css_schedule_eval(old_sch->schid);
 	}
-- 
cgit v1.2.3-70-g09d2


From 6e9a0f67deeca90c433ac40b887cee8da3bdcea2 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:38 +0100
Subject: [S390] cio: quiesce subchannel in io_subchannel_remove

Ensure that there will be no more interrupts for an
unregistered device by using the same quiesce and disable loop
as in io_subchannel_shutdown.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index af500aac24e..bd6e8cf77fa 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1059,6 +1059,8 @@ out_schedule:
 	return 0;
 }
 
+static void io_subchannel_quiesce(struct subchannel *);
+
 static int
 io_subchannel_remove (struct subchannel *sch)
 {
@@ -1068,6 +1070,7 @@ io_subchannel_remove (struct subchannel *sch)
 	cdev = sch_get_cdev(sch);
 	if (!cdev)
 		goto out_free;
+	io_subchannel_quiesce(sch);
 	/* Set ccw device to not operational and drop reference. */
 	spin_lock_irqsave(cdev->ccwlock, flags);
 	sch_set_cdev(sch, NULL);
@@ -1150,7 +1153,7 @@ static int io_subchannel_chp_event(struct subchannel *sch,
 	return 0;
 }
 
-static void io_subchannel_shutdown(struct subchannel *sch)
+static void io_subchannel_quiesce(struct subchannel *sch)
 {
 	struct ccw_device *cdev;
 	int ret;
@@ -1182,6 +1185,11 @@ out_unlock:
 	spin_unlock_irq(sch->lock);
 }
 
+static void io_subchannel_shutdown(struct subchannel *sch)
+{
+	io_subchannel_quiesce(sch);
+}
+
 static int device_is_disconnected(struct ccw_device *cdev)
 {
 	if (!cdev)
-- 
cgit v1.2.3-70-g09d2


From 7a8ad1001c51bba0507ee08cb4323d8ddcb07c70 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:39 +0100
Subject: [S390] cio: change locking in io_subchannel_remove

IO subchannels are always unregistered in process context, so use
spin_lock_irq in the corresponding remove callback.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index bd6e8cf77fa..dc97cb9f227 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1065,17 +1065,16 @@ static int
 io_subchannel_remove (struct subchannel *sch)
 {
 	struct ccw_device *cdev;
-	unsigned long flags;
 
 	cdev = sch_get_cdev(sch);
 	if (!cdev)
 		goto out_free;
 	io_subchannel_quiesce(sch);
 	/* Set ccw device to not operational and drop reference. */
-	spin_lock_irqsave(cdev->ccwlock, flags);
+	spin_lock_irq(cdev->ccwlock);
 	sch_set_cdev(sch, NULL);
 	cdev->private->state = DEV_STATE_NOT_OPER;
-	spin_unlock_irqrestore(cdev->ccwlock, flags);
+	spin_unlock_irq(cdev->ccwlock);
 	ccw_device_unregister(cdev);
 out_free:
 	kfree(sch->private);
-- 
cgit v1.2.3-70-g09d2


From d40f7b75a23d1e59b6ec9d6701231fd4c6992ac6 Mon Sep 17 00:00:00 2001
From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Date: Mon, 7 Dec 2009 12:51:41 +0100
Subject: [S390] cio: dont unregister a busy device in ccw_device_set_offline

If we detect a busy subchannel after the driver's set_offline
callback returned in ccw_device_set_offline, the current behavior
is to unregister the device, which may lead to undesired
consequences. Change this to just quiesce the subchannel and go on
with the offline processing.

Note: This is no excuse for not fixing these drivers -
after the set_offline callback they should have no running IO!

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/cio/device.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

(limited to 'drivers/s390/cio/device.c')

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index dc97cb9f227..9fecfb4223a 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -314,6 +314,8 @@ static void ccw_device_unregister(struct ccw_device *cdev)
 	}
 }
 
+static void io_subchannel_quiesce(struct subchannel *);
+
 /**
  * ccw_device_set_offline() - disable a ccw device for I/O
  * @cdev: target ccw device
@@ -327,7 +329,8 @@ static void ccw_device_unregister(struct ccw_device *cdev)
  */
 int ccw_device_set_offline(struct ccw_device *cdev)
 {
-	int ret;
+	struct subchannel *sch;
+	int ret, state;
 
 	if (!cdev)
 		return -ENODEV;
@@ -341,6 +344,7 @@ int ccw_device_set_offline(struct ccw_device *cdev)
 	}
 	cdev->online = 0;
 	spin_lock_irq(cdev->ccwlock);
+	sch = to_subchannel(cdev->dev.parent);
 	/* Wait until a final state or DISCONNECTED is reached */
 	while (!dev_fsm_final_state(cdev) &&
 	       cdev->private->state != DEV_STATE_DISCONNECTED) {
@@ -349,9 +353,21 @@ int ccw_device_set_offline(struct ccw_device *cdev)
 			   cdev->private->state == DEV_STATE_DISCONNECTED));
 		spin_lock_irq(cdev->ccwlock);
 	}
-	ret = ccw_device_offline(cdev);
-	if (ret)
-		goto error;
+	do {
+		ret = ccw_device_offline(cdev);
+		if (!ret)
+			break;
+		CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
+			      "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
+			      cdev->private->dev_id.devno);
+		if (ret != -EBUSY)
+			goto error;
+		state = cdev->private->state;
+		spin_unlock_irq(cdev->ccwlock);
+		io_subchannel_quiesce(sch);
+		spin_lock_irq(cdev->ccwlock);
+		cdev->private->state = state;
+	} while (ret == -EBUSY);
 	spin_unlock_irq(cdev->ccwlock);
 	wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 		   cdev->private->state == DEV_STATE_DISCONNECTED));
@@ -368,9 +384,6 @@ int ccw_device_set_offline(struct ccw_device *cdev)
 	return 0;
 
 error:
-	CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device 0.%x.%04x\n",
-		      ret, cdev->private->dev_id.ssid,
-		      cdev->private->dev_id.devno);
 	cdev->private->state = DEV_STATE_OFFLINE;
 	dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 	spin_unlock_irq(cdev->ccwlock);
@@ -1059,8 +1072,6 @@ out_schedule:
 	return 0;
 }
 
-static void io_subchannel_quiesce(struct subchannel *);
-
 static int
 io_subchannel_remove (struct subchannel *sch)
 {
-- 
cgit v1.2.3-70-g09d2