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>

3 files changed, 32 insertions, 34 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 3ab99d883888..af5fd716449f 100644
--- a/drivers/s390/cio/cio.c
+++ b/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;
 }
 
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 57b41ec2ed40..d62f5e7f3cf1 100644
--- a/drivers/s390/cio/cio.h
+++ b/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 *);
 
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 054fb428531f..1ebe5d3ddebb 100644
--- a/drivers/s390/cio/css.c
+++ b/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;