[S390] cio: Introduce modalias for css bus.

Add modalias and subchannel type attributes for all subchannels.
I/O subchannel specific attributes are now created in
io_subchannel_probe(). modalias and subchannel type are also
added to the uevent for the css bus. Also make the css modalias
known.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 63 insertions, 6 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index b7f4b52c5a9a..53e7496dc90c 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -2,8 +2,7 @@
  *  drivers/s390/cio/css.c
  *  driver for channel subsystem
  *
- *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
- *                       IBM Corporation
+ *    Copyright IBM Corp. 2002,2008
  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
  *               Cornelia Huck (cornelia.huck@de.ibm.com)
  */
@@ -210,6 +209,41 @@ void css_update_ssd_info(struct subchannel *sch)
         }
 }
 
+static ssize_t type_show(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct subchannel *sch = to_subchannel(dev);
+
+        return sprintf(buf, "%01x\n", sch->st);
+}
+
+static DEVICE_ATTR(type, 0444, type_show, NULL);
+
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+                             char *buf)
+{
+        struct subchannel *sch = to_subchannel(dev);
+
+        return sprintf(buf, "css:t%01X\n", sch->st);
+}
+
+static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
+
+static struct attribute *subch_attrs[] = {
+        &dev_attr_type.attr,
+        &dev_attr_modalias.attr,
+        NULL,
+};
+
+static struct attribute_group subch_attr_group = {
+        .attrs = subch_attrs,
+};
+
+static struct attribute_group *default_subch_attr_groups[] = {
+        &subch_attr_group,
+        NULL,
+};
+
 static int css_register_subchannel(struct subchannel *sch)
 {
         int ret;
@@ -218,16 +252,17 @@ static int css_register_subchannel(struct subchannel *sch)
         sch->dev.parent = &channel_subsystems[0]->device;
         sch->dev.bus = &css_bus_type;
         sch->dev.release = &css_subchannel_release;
-        sch->dev.groups = subch_attr_groups;
+        sch->dev.groups = default_subch_attr_groups;
         /*
          * We don't want to generate uevents for I/O subchannels that don't
          * have a working ccw device behind them since they will be
          * unregistered before they can be used anyway, so we delay the add
          * uevent until after device recognition was successful.
+         * Note that we suppress the uevent for all subchannel types;
+         * the subchannel driver can decide itself when it wants to inform
+         * userspace of its existence.
          */
-        if (!cio_is_console(sch->schid))
-                /* Console is special, no need to suppress. */
-                sch->dev.uevent_suppress = 1;
+        sch->dev.uevent_suppress = 1;
         css_update_ssd_info(sch);
         /* make it known to the system */
         ret = css_sch_device_register(sch);
@@ -236,6 +271,15 @@ static int css_register_subchannel(struct subchannel *sch)
                               sch->schid.ssid, sch->schid.sch_no, ret);
                 return ret;
         }
+        if (!sch->driver) {
+                /*
+                 * No driver matched. Generate the uevent now so that
+                 * a fitting driver module may be loaded based on the
+                 * modalias.
+                 */
+                sch->dev.uevent_suppress = 0;
+                kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+        }
         return ret;
 }
 
@@ -926,12 +970,25 @@ static void css_shutdown(struct device *dev)
                 sch->driver->shutdown(sch);
 }
 
+static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+        struct subchannel *sch = to_subchannel(dev);
+        int ret;
+
+        ret = add_uevent_var(env, "ST=%01X", sch->st);
+        if (ret)
+                return ret;
+        ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
+        return ret;
+}
+
 struct bus_type css_bus_type = {
         .name     = "css",
         .match    = css_bus_match,
         .probe    = css_probe,
         .remove   = css_remove,
         .shutdown = css_shutdown,
+        .uevent   = css_uevent,
 };
 
 /**