s390/css: move subchannel lock allocation

cio_validate_subchannel is used to do some basic checks to find out
if it's worth to further investigate a subchannel. Move the allocation
and initialization of the subchannels locks to css_alloc_subchannel.

Clean up the functions involved while at it.

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/cio.c

@@ -471,15 +471,6 @@ int cio_disable_subchannel(struct subchannel *sch)
 }
 EXPORT_SYMBOL_GPL(cio_disable_subchannel);
 
-int cio_create_sch_lock(struct subchannel *sch)
-{
-	sch->lock = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
-	if (!sch->lock)
-		return -ENOMEM;
-	spin_lock_init(sch->lock);
-	return 0;
-}
-
 static int cio_check_devno_blacklisted(struct subchannel *sch)
 {
 	if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
@@ -536,28 +527,19 @@ int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 	sprintf(dbf_txt, "valsch%x", schid.sch_no);
 	CIO_TRACE_EVENT(4, dbf_txt);
 
-	/* Nuke all fields. */
-	memset(sch, 0, sizeof(struct subchannel));
-
-	sch->schid = schid;
-	err = cio_create_sch_lock(sch);
-	if (err)
-		goto out;
-	mutex_init(&sch->reg_mutex);
-
 	/*
 	 * The first subchannel that is not-operational (ccode==3)
-	 *  indicates that there aren't any more devices available.
+	 * indicates that there aren't any more devices available.
 	 * If stsch gets an exception, it means the current subchannel set
-	 *  is not valid.
+	 * is not valid.
 	 */
-	ccode = stsch_err (schid, &sch->schib);
+	ccode = stsch_err(schid, &sch->schib);
 	if (ccode) {
 		err = (ccode == 3) ? -ENXIO : ccode;
 		goto out;
 	}
-	/* Copy subchannel type from path management control word. */
 	sch->st = sch->schib.pmcw.st;
+	sch->schid = schid;
 
 	switch (sch->st) {
 	case SUBCHANNEL_TYPE_IO:
@@ -574,10 +556,7 @@ int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
 
 	CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
 		      sch->schid.ssid, sch->schid.sch_no, sch->st);
-	return 0;
 out:
-	kfree(sch->lock);
-	sch->lock = NULL;
 	return err;
 }
 

drivers/s390/cio/cio.h

@@ -121,7 +121,6 @@ extern int cio_commit_config(struct subchannel *sch);
 int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key);
 int cio_tm_intrg(struct subchannel *sch);
 
-int cio_create_sch_lock(struct subchannel *);
 void do_adapter_IO(u8 isc);
 void do_IRQ(struct pt_regs *);
 

drivers/s390/cio/css.c

@@ -137,6 +137,18 @@ out:
 
 static void css_sch_todo(struct work_struct *work);
 
+static int css_sch_create_locks(struct subchannel *sch)
+{
+	sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL);
+	if (!sch->lock)
+		return -ENOMEM;
+
+	spin_lock_init(sch->lock);
+	mutex_init(&sch->reg_mutex);
+
+	return 0;
+}
+
 static void css_subchannel_release(struct device *dev)
 {
 	struct subchannel *sch = to_subchannel(dev);
@@ -152,18 +164,26 @@ struct subchannel *css_alloc_subchannel(struct subchannel_id schid)
 	struct subchannel *sch;
 	int ret;
 
-	sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
-	if (sch == NULL)
+	sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA);
+	if (!sch)
 		return ERR_PTR(-ENOMEM);
-	ret = cio_validate_subchannel (sch, schid);
-	if (ret < 0) {
-		kfree(sch);
-		return ERR_PTR(ret);
-	}
+
+	ret = cio_validate_subchannel(sch, schid);
+	if (ret < 0)
+		goto err;
+
+	ret = css_sch_create_locks(sch);
+	if (ret)
+		goto err;
+
 	INIT_WORK(&sch->todo_work, css_sch_todo);
 	sch->dev.release = &css_subchannel_release;
 	device_initialize(&sch->dev);
 	return sch;
+
+err:
+	kfree(sch);
+	return ERR_PTR(ret);
 }
 
 static int css_sch_device_register(struct subchannel *sch)
@@ -756,7 +776,7 @@ static int __init setup_css(int nr)
 	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);
+	ret = css_sch_create_locks(css->pseudo_subchannel);
 	if (ret) {
 		kfree(css->pseudo_subchannel);
 		return ret;