s390/cio: split subchannel registration

Split the subchannel registration in device_initialize and device_add
and move the initialization part inside the allocation function. With
this change we can use refcounting during the complete lifespan of a
subchannel which is important for devices where we do the actually
registration at a later time.

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>

1 files changed, 18 insertions, 19 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 658d9349c837..8a1294b1cbaf 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -137,8 +137,21 @@ out:
 
 static void css_sch_todo(struct work_struct *work);
 
-static struct subchannel *
-css_alloc_subchannel(struct subchannel_id schid)
+static void css_subchannel_release(struct device *dev)
+{
+        struct subchannel *sch;
+
+        sch = to_subchannel(dev);
+        if (!cio_is_console(sch->schid)) {
+                /* Reset intparm to zeroes. */
+                sch->config.intparm = 0;
+                cio_commit_config(sch);
+                kfree(sch->lock);
+                kfree(sch);
+        }
+}
+
+static struct subchannel *css_alloc_subchannel(struct subchannel_id schid)
 {
         struct subchannel *sch;
         int ret;
@@ -152,24 +165,11 @@ css_alloc_subchannel(struct subchannel_id schid)
                 return ERR_PTR(ret);
         }
         INIT_WORK(&sch->todo_work, css_sch_todo);
+        sch->dev.release = &css_subchannel_release;
+        device_initialize(&sch->dev);
         return sch;
 }
 
-static void
-css_subchannel_release(struct device *dev)
-{
-        struct subchannel *sch;
-
-        sch = to_subchannel(dev);
-        if (!cio_is_console(sch->schid)) {
-                /* Reset intparm to zeroes. */
-                sch->config.intparm = 0;
-                cio_commit_config(sch);
-                kfree(sch->lock);
-                kfree(sch);
-        }
-}
-
 static int css_sch_device_register(struct subchannel *sch)
 {
         int ret;
@@ -177,7 +177,7 @@ static int css_sch_device_register(struct subchannel *sch)
         mutex_lock(&sch->reg_mutex);
         dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
                      sch->schid.sch_no);
-        ret = device_register(&sch->dev);
+        ret = device_add(&sch->dev);
         mutex_unlock(&sch->reg_mutex);
         return ret;
 }
@@ -282,7 +282,6 @@ static int css_register_subchannel(struct subchannel *sch)
         /* Initialize the subchannel structure */
         sch->dev.parent = &channel_subsystems[0]->device;
         sch->dev.bus = &css_bus_type;
-        sch->dev.release = &css_subchannel_release;
         sch->dev.groups = default_subch_attr_groups;
         /*
          * We don't want to generate uevents for I/O subchannels that don't