RDS: Add TCP transport to RDS

This code allows RDS to be tunneled over a TCP connection.

RDMA operations are disabled when using TCP transport,
but this frees RDS from the IB/RDMA stack dependency, and allows
it to be used with standard Ethernet adapters, or in a VM.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 74 insertions, 0 deletions

diff --git a/net/rds/tcp_stats.c b/net/rds/tcp_stats.c
new file mode 100644
index 000000000000..d5898d03cd68
--- /dev/null
+++ b/net/rds/tcp_stats.c
@@ -0,0 +1,74 @@
+/*
+ * 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/percpu.h>
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+
+#include "rds.h"
+#include "tcp.h"
+
+DEFINE_PER_CPU(struct rds_tcp_statistics, rds_tcp_stats)
+        ____cacheline_aligned;
+
+static const char const *rds_tcp_stat_names[] = {
+        "tcp_data_ready_calls",
+        "tcp_write_space_calls",
+        "tcp_sndbuf_full",
+        "tcp_connect_raced",
+        "tcp_listen_closed_stale",
+};
+
+unsigned int rds_tcp_stats_info_copy(struct rds_info_iterator *iter,
+                                     unsigned int avail)
+{
+        struct rds_tcp_statistics stats = {0, };
+        uint64_t *src;
+        uint64_t *sum;
+        size_t i;
+        int cpu;
+
+        if (avail < ARRAY_SIZE(rds_tcp_stat_names))
+                goto out;
+
+        for_each_online_cpu(cpu) {
+                src = (uint64_t *)&(per_cpu(rds_tcp_stats, cpu));
+                sum = (uint64_t *)&stats;
+                for (i = 0; i < sizeof(stats) / sizeof(uint64_t); i++)
+                        *(sum++) += *(src++);
+        }
+
+        rds_stats_info_copy(iter, (uint64_t *)&stats, rds_tcp_stat_names,
+                            ARRAY_SIZE(rds_tcp_stat_names));
+out:
+        return ARRAY_SIZE(rds_tcp_stat_names);
+}