File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/dcb/dcbevent.c b/net/dcb/dcbevent.c
new file mode 100644
index 0000000..a520d80
--- /dev/null
+++ b/net/dcb/dcbevent.c
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2010, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: John Fastabend <john.r.fastabend@intel.com>
+ */
+
+#include <linux/rtnetlink.h>
+#include <linux/notifier.h>
+#include <linux/export.h>
+#include <net/dcbevent.h>
+
+static ATOMIC_NOTIFIER_HEAD(dcbevent_notif_chain);
+
+int register_dcbevent_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&dcbevent_notif_chain, nb);
+}
+EXPORT_SYMBOL(register_dcbevent_notifier);
+
+int unregister_dcbevent_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&dcbevent_notif_chain, nb);
+}
+EXPORT_SYMBOL(unregister_dcbevent_notifier);
+
+int call_dcbevent_notifiers(unsigned long val, void *v)
+{
+	return atomic_notifier_call_chain(&dcbevent_notif_chain, val, v);
+}