16 files changed, 162 insertions, 100 deletions

diff --git a/drivers/s390/cio/airq.c b/drivers/s390/cio/airq.c
index 445564c790f6..00bfbee0af9e 100644
--- a/drivers/s390/cio/airq.c
+++ b/drivers/s390/cio/airq.c
@@ -196,11 +196,11 @@ EXPORT_SYMBOL(airq_iv_release);
  */
 unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
 {
-	unsigned long bit, i;
+	unsigned long bit, i, flags;
 
 	if (!iv->avail || num == 0)
 		return -1UL;
-	spin_lock(&iv->lock);
+	spin_lock_irqsave(&iv->lock, flags);
 	bit = find_first_bit_inv(iv->avail, iv->bits);
 	while (bit + num <= iv->bits) {
 		for (i = 1; i < num; i++)
@@ -218,9 +218,8 @@ unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num)
 	}
 	if (bit + num > iv->bits)
 		bit = -1UL;
-	spin_unlock(&iv->lock);
+	spin_unlock_irqrestore(&iv->lock, flags);
 	return bit;
-
 }
 EXPORT_SYMBOL(airq_iv_alloc);
 
@@ -232,11 +231,11 @@ EXPORT_SYMBOL(airq_iv_alloc);
  */
 void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
 {
-	unsigned long i;
+	unsigned long i, flags;
 
 	if (!iv->avail || num == 0)
 		return;
-	spin_lock(&iv->lock);
+	spin_lock_irqsave(&iv->lock, flags);
 	for (i = 0; i < num; i++) {
 		/* Clear (possibly left over) interrupt bit */
 		clear_bit_inv(bit + i, iv->vector);
@@ -248,7 +247,7 @@ void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num)
 		while (iv->end > 0 && !test_bit_inv(iv->end - 1, iv->avail))
 			iv->end--;
 	}
-	spin_unlock(&iv->lock);
+	spin_unlock_irqrestore(&iv->lock, flags);
 }
 EXPORT_SYMBOL(airq_iv_free);
 
diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index dfd7bc681c25..e443b0d0b236 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -184,7 +184,7 @@ static ssize_t ccwgroup_ungroup_store(struct device *dev,
 				      const char *buf, size_t count)
 {
 	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-	int rc;
+	int rc = 0;
 
 	/* Prevent concurrent online/offline processing and ungrouping. */
 	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
@@ -196,11 +196,12 @@ static ssize_t ccwgroup_ungroup_store(struct device *dev,
 
 	if (device_remove_file_self(dev, attr))
 		ccwgroup_ungroup(gdev);
+	else
+		rc = -ENODEV;
 out:
 	if (rc) {
-		if (rc != -EAGAIN)
-			/* Release onoff "lock" when ungrouping failed. */
-			atomic_set(&gdev->onoff, 0);
+		/* Release onoff "lock" when ungrouping failed. */
+		atomic_set(&gdev->onoff, 0);
 		return rc;
 	}
 	return count;
@@ -227,6 +228,7 @@ static void ccwgroup_ungroup_workfn(struct work_struct *work)
 		container_of(work, struct ccwgroup_device, ungroup_work);
 
 	ccwgroup_ungroup(gdev);
+	put_device(&gdev->dev);
 }
 
 static void ccwgroup_release(struct device *dev)
@@ -412,8 +414,10 @@ static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
 {
 	struct ccwgroup_device *gdev = to_ccwgroupdev(data);
 
-	if (action == BUS_NOTIFY_UNBIND_DRIVER)
+	if (action == BUS_NOTIFY_UNBIND_DRIVER) {
+		get_device(&gdev->dev);
 		schedule_work(&gdev->ungroup_work);
+	}
 
 	return NOTIFY_OK;
 }
@@ -582,11 +586,7 @@ void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
 					 __ccwgroup_match_all))) {
 		struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
 
-		mutex_lock(&gdev->reg_mutex);
-		__ccwgroup_remove_symlinks(gdev);
-		device_unregister(dev);
-		__ccwgroup_remove_cdev_refs(gdev);
-		mutex_unlock(&gdev->reg_mutex);
+		ccwgroup_ungroup(gdev);
 		put_device(dev);
 	}
 	driver_unregister(&cdriver->driver);
@@ -633,13 +633,7 @@ void ccwgroup_remove_ccwdev(struct ccw_device *cdev)
 	get_device(&gdev->dev);
 	spin_unlock_irq(cdev->ccwlock);
 	/* Unregister group device. */
-	mutex_lock(&gdev->reg_mutex);
-	if (device_is_registered(&gdev->dev)) {
-		__ccwgroup_remove_symlinks(gdev);
-		device_unregister(&gdev->dev);
-		__ccwgroup_remove_cdev_refs(gdev);
-	}
-	mutex_unlock(&gdev->reg_mutex);
+	ccwgroup_ungroup(gdev);
 	/* Release ccwgroup device reference for local processing. */
 	put_device(&gdev->dev);
 }
diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c
index 5156264d0c74..07676c22d514 100644
--- a/drivers/s390/cio/ccwreq.c
+++ b/drivers/s390/cio/ccwreq.c
@@ -46,7 +46,7 @@ static u16 ccwreq_next_path(struct ccw_device *cdev)
 		goto out;
 	}
 	req->retries	= req->maxretries;
-	req->mask	= lpm_adjust(req->mask >>= 1, req->lpm);
+	req->mask	= lpm_adjust(req->mask >> 1, req->lpm);
 out:
 	return req->mask;
 }
@@ -252,7 +252,7 @@ static void ccwreq_log_status(struct ccw_device *cdev, enum io_status status)
  */
 void ccw_request_handler(struct ccw_device *cdev)
 {
-	struct irb *irb = (struct irb *)&S390_lowcore.irb;
+	struct irb *irb = &__get_cpu_var(cio_irb);
 	struct ccw_request *req = &cdev->private->req;
 	enum io_status status;
 	int rc = -EOPNOTSUPP;
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 6c440d4349d4..d497aa05a72f 100644
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -509,7 +509,7 @@ out:
  * On success return a newly allocated copy of the channel-path description
  * data associated with the given channel-path ID. Return %NULL on error.
  */
-void *chp_get_chp_desc(struct chp_id chpid)
+struct channel_path_desc *chp_get_chp_desc(struct chp_id chpid)
 {
 	struct channel_path *chp;
 	struct channel_path_desc *desc;
diff --git a/drivers/s390/cio/chp.h b/drivers/s390/cio/chp.h
index 9284b785a06f..4efd5b867cc3 100644
--- a/drivers/s390/cio/chp.h
+++ b/drivers/s390/cio/chp.h
@@ -60,7 +60,7 @@ static inline struct channel_path *chpid_to_chp(struct chp_id chpid)
 int chp_get_status(struct chp_id chpid);
 u8 chp_get_sch_opm(struct subchannel *sch);
 int chp_is_registered(struct chp_id chpid);
-void *chp_get_chp_desc(struct chp_id chpid);
+struct channel_path_desc *chp_get_chp_desc(struct chp_id chpid);
 void chp_remove_cmg_attr(struct channel_path *chp);
 int chp_add_cmg_attr(struct channel_path *chp);
 int chp_update_desc(struct channel_path *chp);
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 7e53a9c8b0b9..76c9b50700b2 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -21,17 +21,6 @@ struct cmg_entry {
 	u32 values[NR_MEASUREMENT_ENTRIES];
 } __attribute__ ((packed));
 
-struct channel_path_desc {
-	u8 flags;
-	u8 lsn;
-	u8 desc;
-	u8 chpid;
-	u8 swla;
-	u8 zeroes;
-	u8 chla;
-	u8 chpp;
-} __attribute__ ((packed));
-
 struct channel_path_desc_fmt1 {
 	u8 flags;
 	u8 lsn;
diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index 1d3661af7bd8..3d22d2a4ce14 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -58,7 +58,7 @@ static void chsc_subchannel_irq(struct subchannel *sch)
 {
 	struct chsc_private *private = dev_get_drvdata(&sch->dev);
 	struct chsc_request *request = private->request;
-	struct irb *irb = (struct irb *)&S390_lowcore.irb;
+	struct irb *irb = &__get_cpu_var(cio_irb);
 
 	CHSC_LOG(4, "irb");
 	CHSC_LOG_HEX(4, irb, sizeof(*irb));
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 9e058c4657a3..2905d8b0ec95 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -46,6 +46,9 @@ debug_info_t *cio_debug_msg_id;
 debug_info_t *cio_debug_trace_id;
 debug_info_t *cio_debug_crw_id;
 
+DEFINE_PER_CPU_ALIGNED(struct irb, cio_irb);
+EXPORT_PER_CPU_SYMBOL(cio_irb);
+
 /*
  * Function: cio_debug_init
  * Initializes three debug logs for common I/O:
@@ -560,7 +563,7 @@ static irqreturn_t do_cio_interrupt(int irq, void *dummy)
 
 	__this_cpu_write(s390_idle.nohz_delay, 1);
 	tpi_info = (struct tpi_info *) &get_irq_regs()->int_code;
-	irb = (struct irb *) &S390_lowcore.irb;
+	irb = &__get_cpu_var(cio_irb);
 	sch = (struct subchannel *)(unsigned long) tpi_info->intparm;
 	if (!sch) {
 		/* Clear pending interrupt condition. */
@@ -599,6 +602,7 @@ void __init init_cio_interrupts(void)
 
 #ifdef CONFIG_CCW_CONSOLE
 static struct subchannel *console_sch;
+static struct lock_class_key console_sch_key;
 
 /*
  * Use cio_tsch to update the subchannel status and call the interrupt handler
@@ -609,7 +613,7 @@ void cio_tsch(struct subchannel *sch)
 	struct irb *irb;
 	int irq_context;
 
-	irb = (struct irb *)&S390_lowcore.irb;
+	irb = &__get_cpu_var(cio_irb);
 	/* Store interrupt response block to lowcore. */
 	if (tsch(sch->schid, irb) != 0)
 		/* Not status pending or not operational. */
@@ -683,6 +687,7 @@ struct subchannel *cio_probe_console(void)
 	if (IS_ERR(sch))
 		return sch;
 
+	lockdep_set_class(sch->lock, &console_sch_key);
 	isc_register(CONSOLE_ISC);
 	sch->config.isc = CONSOLE_ISC;
 	sch->config.intparm = (u32)(addr_t)sch;
@@ -746,7 +751,7 @@ __clear_io_subchannel_easy(struct subchannel_id schid)
 		struct tpi_info ti;
 
 		if (tpi(&ti)) {
-			tsch(ti.schid, (struct irb *)&S390_lowcore.irb);
+			tsch(ti.schid, &__get_cpu_var(cio_irb));
 			if (schid_equal(&ti.schid, &schid))
 				return 0;
 		}
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index d42f67412bd8..a01376ae1749 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -102,6 +102,8 @@ struct subchannel {
 	struct schib_config config;
 } __attribute__ ((aligned(8)));
 
+DECLARE_PER_CPU(struct irb, cio_irb);
+
 #define to_subchannel(n) container_of(n, struct subchannel, dev)
 
 extern int cio_validate_subchannel (struct subchannel *, struct subchannel_id);
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index d8d9b5b5cc56..dfef5e63cb7b 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -678,18 +678,11 @@ static const struct attribute_group *ccwdev_attr_groups[] = {
 	NULL,
 };
 
-/* this is a simple abstraction for device_register that sets the
- * correct bus type and adds the bus specific files */
-static int ccw_device_register(struct ccw_device *cdev)
+static int ccw_device_add(struct ccw_device *cdev)
 {
 	struct device *dev = &cdev->dev;
-	int ret;
 
 	dev->bus = &ccw_bus_type;
-	ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
-			   cdev->private->dev_id.devno);
-	if (ret)
-		return ret;
 	return device_add(dev);
 }
 
@@ -764,22 +757,46 @@ static void ccw_device_todo(struct work_struct *work);
 static int io_subchannel_initialize_dev(struct subchannel *sch,
 					struct ccw_device *cdev)
 {
-	cdev->private->cdev = cdev;
-	cdev->private->int_class = IRQIO_CIO;
-	atomic_set(&cdev->private->onoff, 0);
+	struct ccw_device_private *priv = cdev->private;
+	int ret;
+
+	priv->cdev = cdev;
+	priv->int_class = IRQIO_CIO;
+	priv->state = DEV_STATE_NOT_OPER;
+	priv->dev_id.devno = sch->schib.pmcw.dev;
+	priv->dev_id.ssid = sch->schid.ssid;
+	priv->schid = sch->schid;
+
+	INIT_WORK(&priv->todo_work, ccw_device_todo);
+	INIT_LIST_HEAD(&priv->cmb_list);
+	init_waitqueue_head(&priv->wait_q);
+	init_timer(&priv->timer);
+
+	atomic_set(&priv->onoff, 0);
+	cdev->ccwlock = sch->lock;
 	cdev->dev.parent = &sch->dev;
 	cdev->dev.release = ccw_device_release;
-	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);
+	ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
+			   cdev->private->dev_id.devno);
+	if (ret)
+		goto out_put;
 	if (!get_device(&sch->dev)) {
-		/* Release reference from device_initialize(). */
-		put_device(&cdev->dev);
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_put;
 	}
-	cdev->private->flags.initialized = 1;
+	priv->flags.initialized = 1;
+	spin_lock_irq(sch->lock);
+	sch_set_cdev(sch, cdev);
+	spin_unlock_irq(sch->lock);
 	return 0;
+
+out_put:
+	/* Release reference from device_initialize(). */
+	put_device(&cdev->dev);
+	return ret;
 }
 
 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
@@ -858,7 +875,7 @@ static void io_subchannel_register(struct ccw_device *cdev)
 	dev_set_uevent_suppress(&sch->dev, 0);
 	kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 	/* make it known to the system */
-	ret = ccw_device_register(cdev);
+	ret = ccw_device_add(cdev);
 	if (ret) {
 		CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 			      cdev->private->dev_id.ssid,
@@ -923,26 +940,11 @@ io_subchannel_recog_done(struct ccw_device *cdev)
 
 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 {
-	struct ccw_device_private *priv;
-
-	cdev->ccwlock = sch->lock;
-
-	/* Init private data. */
-	priv = cdev->private;
-	priv->dev_id.devno = sch->schib.pmcw.dev;
-	priv->dev_id.ssid = sch->schid.ssid;
-	priv->schid = sch->schid;
-	priv->state = DEV_STATE_NOT_OPER;
-	INIT_LIST_HEAD(&priv->cmb_list);
-	init_waitqueue_head(&priv->wait_q);
-	init_timer(&priv->timer);
-
 	/* Increase counter of devices currently in recognition. */
 	atomic_inc(&ccw_device_init_count);
 
 	/* Start async. device sensing. */
 	spin_lock_irq(sch->lock);
-	sch_set_cdev(sch, cdev);
 	ccw_device_recognition(cdev);
 	spin_unlock_irq(sch->lock);
 }
@@ -1083,7 +1085,7 @@ static int io_subchannel_probe(struct subchannel *sch)
 		dev_set_uevent_suppress(&sch->dev, 0);
 		kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 		cdev = sch_get_cdev(sch);
-		rc = ccw_device_register(cdev);
+		rc = ccw_device_add(cdev);
 		if (rc) {
 			/* Release online reference. */
 			put_device(&cdev->dev);
@@ -1597,7 +1599,6 @@ int __init ccw_device_enable_console(struct ccw_device *cdev)
 	if (rc)
 		return rc;
 	sch->driver = &io_subchannel_driver;
-	sch_set_cdev(sch, cdev);
 	io_subchannel_recog(cdev, sch);
 	/* Now wait for the async. recognition to come to an end. */
 	spin_lock_irq(cdev->ccwlock);
@@ -1639,6 +1640,7 @@ struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
 		put_device(&sch->dev);
 		return ERR_PTR(-ENOMEM);
 	}
+	set_io_private(sch, io_priv);
 	cdev = io_subchannel_create_ccwdev(sch);
 	if (IS_ERR(cdev)) {
 		put_device(&sch->dev);
@@ -1646,7 +1648,6 @@ struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
 		return cdev;
 	}
 	cdev->drv = drv;
-	set_io_private(sch, io_priv);
 	ccw_device_set_int_class(cdev);
 	return cdev;
 }
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index c7638c543250..0bc902b3cd84 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -739,7 +739,7 @@ ccw_device_irq(struct ccw_device *cdev, enum dev_event dev_event)
 	struct irb *irb;
 	int is_cmd;
 
-	irb = (struct irb *)&S390_lowcore.irb;
+	irb = &__get_cpu_var(cio_irb);
 	is_cmd = !scsw_is_tm(&irb->scsw);
 	/* Check for unsolicited interrupt. */
 	if (!scsw_is_solicited(&irb->scsw)) {
@@ -805,7 +805,7 @@ ccw_device_w4sense(struct ccw_device *cdev, enum dev_event dev_event)
 {
 	struct irb *irb;
 
-	irb = (struct irb *)&S390_lowcore.irb;
+	irb = &__get_cpu_var(cio_irb);
 	/* Check for unsolicited interrupt. */
 	if (scsw_stctl(&irb->scsw) ==
 	    (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index 4845d64f2842..f3c417943dad 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -563,14 +563,23 @@ out_unlock:
 	return rc;
 }
 
-void *ccw_device_get_chp_desc(struct ccw_device *cdev, int chp_no)
+/**
+ * chp_get_chp_desc - return newly allocated channel-path descriptor
+ * @cdev: device to obtain the descriptor for
+ * @chp_idx: index of the channel path
+ *
+ * On success return a newly allocated copy of the channel-path description
+ * data associated with the given channel path. Return %NULL on error.
+ */
+struct channel_path_desc *ccw_device_get_chp_desc(struct ccw_device *cdev,
+						  int chp_idx)
 {
 	struct subchannel *sch;
 	struct chp_id chpid;
 
 	sch = to_subchannel(cdev->dev.parent);
 	chp_id_init(&chpid);
-	chpid.id = sch->schib.pmcw.chpid[chp_no];
+	chpid.id = sch->schib.pmcw.chpid[chp_idx];
 	return chp_get_chp_desc(chpid);
 }
 
diff --git a/drivers/s390/cio/eadm_sch.c b/drivers/s390/cio/eadm_sch.c
index 3a2ee4a740b4..c4f7bf3e24c2 100644
--- a/drivers/s390/cio/eadm_sch.c
+++ b/drivers/s390/cio/eadm_sch.c
@@ -134,7 +134,7 @@ static void eadm_subchannel_irq(struct subchannel *sch)
 {
 	struct eadm_private *private = get_eadm_private(sch);
 	struct eadm_scsw *scsw = &sch->schib.scsw.eadm;
-	struct irb *irb = (struct irb *)&S390_lowcore.irb;
+	struct irb *irb = &__get_cpu_var(cio_irb);
 	int error = 0;
 
 	EADM_LOG(6, "irq");
diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 4221b02085ad..f1f3baa8e6e4 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -7,6 +7,7 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/export.h>
+#include <linux/slab.h>
 #include <asm/debug.h>
 #include "qdio_debug.h"
 #include "qdio.h"
@@ -16,11 +17,51 @@ debug_info_t *qdio_dbf_error;
 
 static struct dentry *debugfs_root;
 #define QDIO_DEBUGFS_NAME_LEN	10
+#define QDIO_DBF_NAME_LEN	20
 
-void qdio_allocate_dbf(struct qdio_initialize *init_data,
+struct qdio_dbf_entry {
+	char dbf_name[QDIO_DBF_NAME_LEN];
+	debug_info_t *dbf_info;
+	struct list_head dbf_list;
+};
+
+static LIST_HEAD(qdio_dbf_list);
+static DEFINE_MUTEX(qdio_dbf_list_mutex);
+
+static debug_info_t *qdio_get_dbf_entry(char *name)
+{
+	struct qdio_dbf_entry *entry;
+	debug_info_t *rc = NULL;
+
+	mutex_lock(&qdio_dbf_list_mutex);
+	list_for_each_entry(entry, &qdio_dbf_list, dbf_list) {
+		if (strcmp(entry->dbf_name, name) == 0) {
+			rc = entry->dbf_info;
+			break;
+		}
+	}
+	mutex_unlock(&qdio_dbf_list_mutex);
+	return rc;
+}
+
+static void qdio_clear_dbf_list(void)
+{
+	struct qdio_dbf_entry *entry, *tmp;
+
+	mutex_lock(&qdio_dbf_list_mutex);
+	list_for_each_entry_safe(entry, tmp, &qdio_dbf_list, dbf_list) {
+		list_del(&entry->dbf_list);
+		debug_unregister(entry->dbf_info);
+		kfree(entry);
+	}
+	mutex_unlock(&qdio_dbf_list_mutex);
+}
+
+int qdio_allocate_dbf(struct qdio_initialize *init_data,
 		       struct qdio_irq *irq_ptr)
 {
-	char text[20];
+	char text[QDIO_DBF_NAME_LEN];
+	struct qdio_dbf_entry *new_entry;
 
 	DBF_EVENT("qfmt:%1d", init_data->q_format);
 	DBF_HEX(init_data->adapter_name, 8);
@@ -38,11 +79,34 @@ void qdio_allocate_dbf(struct qdio_initialize *init_data,
 	DBF_EVENT("irq:%8lx", (unsigned long)irq_ptr);
 
 	/* allocate trace view for the interface */
-	snprintf(text, 20, "qdio_%s", dev_name(&init_data->cdev->dev));
-	irq_ptr->debug_area = debug_register(text, 2, 1, 16);
-	debug_register_view(irq_ptr->debug_area, &debug_hex_ascii_view);
-	debug_set_level(irq_ptr->debug_area, DBF_WARN);
-	DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf created");
+	snprintf(text, QDIO_DBF_NAME_LEN, "qdio_%s",
+					dev_name(&init_data->cdev->dev));
+	irq_ptr->debug_area = qdio_get_dbf_entry(text);
+	if (irq_ptr->debug_area)
+		DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf reused");
+	else {
+		irq_ptr->debug_area = debug_register(text, 2, 1, 16);
+		if (!irq_ptr->debug_area)
+			return -ENOMEM;
+		if (debug_register_view(irq_ptr->debug_area,
+						&debug_hex_ascii_view)) {
+			debug_unregister(irq_ptr->debug_area);
+			return -ENOMEM;
+		}
+		debug_set_level(irq_ptr->debug_area, DBF_WARN);
+		DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf created");
+		new_entry = kzalloc(sizeof(struct qdio_dbf_entry), GFP_KERNEL);
+		if (!new_entry) {
+			debug_unregister(irq_ptr->debug_area);
+			return -ENOMEM;
+		}
+		strlcpy(new_entry->dbf_name, text, QDIO_DBF_NAME_LEN);
+		new_entry->dbf_info = irq_ptr->debug_area;
+		mutex_lock(&qdio_dbf_list_mutex);
+		list_add(&new_entry->dbf_list, &qdio_dbf_list);
+		mutex_unlock(&qdio_dbf_list_mutex);
+	}
+	return 0;
 }
 
 static int qstat_show(struct seq_file *m, void *v)
@@ -300,6 +364,7 @@ int __init qdio_debug_init(void)
 
 void qdio_debug_exit(void)
 {
+	qdio_clear_dbf_list();
 	debugfs_remove(debugfs_root);
 	if (qdio_dbf_setup)
 		debug_unregister(qdio_dbf_setup);
diff --git a/drivers/s390/cio/qdio_debug.h b/drivers/s390/cio/qdio_debug.h
index dfac9bfefea3..f33ce8577619 100644
--- a/drivers/s390/cio/qdio_debug.h
+++ b/drivers/s390/cio/qdio_debug.h
@@ -75,7 +75,7 @@ static inline void DBF_DEV_HEX(struct qdio_irq *dev, void *addr,
 	}
 }
 
-void qdio_allocate_dbf(struct qdio_initialize *init_data,
+int qdio_allocate_dbf(struct qdio_initialize *init_data,
 		       struct qdio_irq *irq_ptr);
 void qdio_setup_debug_entries(struct qdio_irq *irq_ptr,
 			      struct ccw_device *cdev);
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 77466c4faabb..848e3b64ea6e 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -409,17 +409,16 @@ static inline void qdio_stop_polling(struct qdio_q *q)
 		set_buf_state(q, q->u.in.ack_start, SLSB_P_INPUT_NOT_INIT);
 }
 
-static inline void account_sbals(struct qdio_q *q, int count)
+static inline void account_sbals(struct qdio_q *q, unsigned int count)
 {
-	int pos = 0;
+	int pos;
 
 	q->q_stats.nr_sbal_total += count;
 	if (count == QDIO_MAX_BUFFERS_MASK) {
 		q->q_stats.nr_sbals[7]++;
 		return;
 	}
-	while (count >>= 1)
-		pos++;
+	pos = ilog2(count);
 	q->q_stats.nr_sbals[pos]++;
 }
 
@@ -1234,12 +1233,10 @@ int qdio_free(struct ccw_device *cdev)
 		return -ENODEV;
 
 	DBF_EVENT("qfree:%4x", cdev->private->schid.sch_no);
+	DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf abandoned");
 	mutex_lock(&irq_ptr->setup_mutex);
 
-	if (irq_ptr->debug_area != NULL) {
-		debug_unregister(irq_ptr->debug_area);
-		irq_ptr->debug_area = NULL;
-	}
+	irq_ptr->debug_area = NULL;
 	cdev->private->qdio_data = NULL;
 	mutex_unlock(&irq_ptr->setup_mutex);
 
@@ -1276,7 +1273,8 @@ int qdio_allocate(struct qdio_initialize *init_data)
 		goto out_err;
 
 	mutex_init(&irq_ptr->setup_mutex);
-	qdio_allocate_dbf(init_data, irq_ptr);
+	if (qdio_allocate_dbf(init_data, irq_ptr))
+		goto out_rel;
 
 	/*
 	 * Allocate a page for the chsc calls in qdio_establish.