xen: Module autoprobing support for frontend drivers

Add module aliases to support autoprobing modules
for xen frontend devices.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 25 insertions, 2 deletions

diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 88fc5ec665f5..57ceb5346b74 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -88,6 +88,16 @@ int xenbus_match(struct device *_dev, struct device_driver *_drv)
         return match_device(drv->ids, to_xenbus_device(_dev)) != NULL;
 }
 
+static int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env)
+{
+        struct xenbus_device *dev = to_xenbus_device(_dev);
+
+        if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype))
+                return -ENOMEM;
+
+        return 0;
+}
+
 /* device/<type>/<id> => <type>-<id> */
 static int frontend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename)
 {
@@ -166,6 +176,7 @@ static struct xen_bus_type xenbus_frontend = {
         .bus = {
                 .name     = "xen",
                 .match    = xenbus_match,
+                .uevent   = xenbus_uevent,
                 .probe    = xenbus_dev_probe,
                 .remove   = xenbus_dev_remove,
                 .shutdown = xenbus_dev_shutdown,
@@ -438,6 +449,12 @@ static ssize_t xendev_show_devtype(struct device *dev,
 }
 DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL);
 
+static ssize_t xendev_show_modalias(struct device *dev,
+                                    struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "xen:%s\n", to_xenbus_device(dev)->devicetype);
+}
+DEVICE_ATTR(modalias, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_modalias, NULL);
 
 int xenbus_probe_node(struct xen_bus_type *bus,
                       const char *type,
@@ -492,10 +509,16 @@ int xenbus_probe_node(struct xen_bus_type *bus,
 
         err = device_create_file(&xendev->dev, &dev_attr_devtype);
         if (err)
-                goto fail_remove_file;
+                goto fail_remove_nodename;
+
+        err = device_create_file(&xendev->dev, &dev_attr_modalias);
+        if (err)
+                goto fail_remove_devtype;
 
         return 0;
-fail_remove_file:
+fail_remove_devtype:
+        device_remove_file(&xendev->dev, &dev_attr_devtype);
+fail_remove_nodename:
         device_remove_file(&xendev->dev, &dev_attr_nodename);
 fail_unregister:
         device_unregister(&xendev->dev);