[04/21] RDS: Transport code

diff --git a/drivers/infiniband/ulp/rds/transport.c b/drivers/infiniband/ulp/rds/transport.c
new file mode 100644
index 0000000..e78f8b3
--- /dev/null
+++ b/drivers/infiniband/ulp/rds/transport.c
@@ -0,0 +1,134 @@ 
+/*
+ * Copyright (c) 2006 Oracle.  All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/in.h>
+
+#include "rds.h"
+#include "loop.h"
+
+static LIST_HEAD(transports);
+static DECLARE_RWSEM(trans_sem);
+
+int rds_trans_register(struct rds_transport *trans)
+{
+	BUG_ON(strlen(trans->t_name) + 1 >
+	       sizeof(((struct rds_info_connection *)0)->transport));
+
+	down_write(&trans_sem);
+
+	list_add_tail(&trans->t_item, &transports);
+	printk(KERN_INFO "Registered RDS/%s transport\n", trans->t_name);
+
+	up_write(&trans_sem);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rds_trans_register);
+
+void rds_trans_unregister(struct rds_transport *trans)
+{
+	down_write(&trans_sem);
+
+	list_del_init(&trans->t_item);
+	printk(KERN_INFO "Unregistered RDS/%s transport\n", trans->t_name);
+
+	up_write(&trans_sem);
+}
+EXPORT_SYMBOL_GPL(rds_trans_unregister);
+
+struct rds_transport *rds_trans_get_preferred(__be32 addr)
+{
+	struct rds_transport *trans;
+	struct rds_transport *ret = NULL;
+
+        if (IN_LOOPBACK(ntohl(addr)))
+                return &rds_loop_transport;
+
+	down_read(&trans_sem);
+	list_for_each_entry(trans, &transports, t_item) {
+		if (trans->laddr_check(addr) == 0) {
+			ret = trans;
+			break;
+		}
+	}
+	up_read(&trans_sem);
+
+	return ret;
+}
+
+/* TODO remove this, only called in rds_exit, by which point we know
+   all the transports will have been unloaded */
+void rds_trans_stop_listening(void)
+{
+	struct rds_transport *trans;
+
+	down_read(&trans_sem);
+
+	list_for_each_entry(trans, &transports, t_item)
+		trans->listen_stop();
+
+	up_read(&trans_sem);
+}
+
+/*
+ * This returns the number of stats entries in the snapshot and only
+ * copies them using the iter if there is enough space for them.  The
+ * caller passes in the global stats so that we can size and copy while
+ * holding the lock.
+ */
+unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
+				       unsigned int avail)
+
+{
+	struct rds_transport *trans;
+	unsigned int total = 0;
+	unsigned int part;
+
+	rds_info_iter_unmap(iter);
+	down_read(&trans_sem);
+
+	list_for_each_entry(trans, &transports, t_item) {
+		if (trans->stats_info_copy == NULL)
+			continue;
+
+		part = trans->stats_info_copy(iter, avail);
+		avail -= min(avail, part);
+		total += part;
+	}
+
+	up_read(&trans_sem);
+
+	return total;
+}
+