Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 758 insertions, 0 deletions

diff --git a/kernel/net/sunrpc/xprtrdma/transport.c b/kernel/net/sunrpc/xprtrdma/transport.c
new file mode 100644
index 000000000..54f23b1be
--- /dev/null
+++ b/kernel/net/sunrpc/xprtrdma/transport.c
@@ -0,0 +1,758 @@
+/*
+ * Copyright (c) 2003-2007 Network Appliance, Inc. 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 BSD-type
+ * 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.
+ *
+ *      Neither the name of the Network Appliance, Inc. nor the names of
+ *      its contributors may be used to endorse or promote products
+ *      derived from this software without specific prior written
+ *      permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * transport.c
+ *
+ * This file contains the top-level implementation of an RPC RDMA
+ * transport.
+ *
+ * Naming convention: functions beginning with xprt_ are part of the
+ * transport switch. All others are RPC RDMA internal.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <linux/sunrpc/addr.h>
+
+#include "xprt_rdma.h"
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+# define RPCDBG_FACILITY	RPCDBG_TRANS
+#endif
+
+MODULE_LICENSE("Dual BSD/GPL");
+
+MODULE_DESCRIPTION("RPC/RDMA Transport for Linux kernel NFS");
+MODULE_AUTHOR("Network Appliance, Inc.");
+
+/*
+ * tunables
+ */
+
+static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
+static unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
+static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
+static unsigned int xprt_rdma_inline_write_padding;
+static unsigned int xprt_rdma_memreg_strategy = RPCRDMA_FRMR;
+		int xprt_rdma_pad_optimize = 1;
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+
+static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
+static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
+static unsigned int zero;
+static unsigned int max_padding = PAGE_SIZE;
+static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
+static unsigned int max_memreg = RPCRDMA_LAST - 1;
+
+static struct ctl_table_header *sunrpc_table_header;
+
+static struct ctl_table xr_tunables_table[] = {
+	{
+		.procname	= "rdma_slot_table_entries",
+		.data		= &xprt_rdma_slot_table_entries,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &min_slot_table_size,
+		.extra2		= &max_slot_table_size
+	},
+	{
+		.procname	= "rdma_max_inline_read",
+		.data		= &xprt_rdma_max_inline_read,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "rdma_max_inline_write",
+		.data		= &xprt_rdma_max_inline_write,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "rdma_inline_write_padding",
+		.data		= &xprt_rdma_inline_write_padding,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &max_padding,
+	},
+	{
+		.procname	= "rdma_memreg_strategy",
+		.data		= &xprt_rdma_memreg_strategy,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &min_memreg,
+		.extra2		= &max_memreg,
+	},
+	{
+		.procname	= "rdma_pad_optimize",
+		.data		= &xprt_rdma_pad_optimize,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{ },
+};
+
+static struct ctl_table sunrpc_table[] = {
+	{
+		.procname	= "sunrpc",
+		.mode		= 0555,
+		.child		= xr_tunables_table
+	},
+	{ },
+};
+
+#endif
+
+#define RPCRDMA_BIND_TO		(60U * HZ)
+#define RPCRDMA_INIT_REEST_TO	(5U * HZ)
+#define RPCRDMA_MAX_REEST_TO	(30U * HZ)
+#define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
+
+static struct rpc_xprt_ops xprt_rdma_procs;	/* forward reference */
+
+static void
+xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+	char buf[20];
+
+	snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
+	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
+
+	xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
+}
+
+static void
+xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
+{
+	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+	char buf[40];
+
+	snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
+	xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
+
+	xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
+}
+
+static void
+xprt_rdma_format_addresses(struct rpc_xprt *xprt)
+{
+	struct sockaddr *sap = (struct sockaddr *)
+					&rpcx_to_rdmad(xprt).addr;
+	char buf[128];
+
+	switch (sap->sa_family) {
+	case AF_INET:
+		xprt_rdma_format_addresses4(xprt, sap);
+		break;
+	case AF_INET6:
+		xprt_rdma_format_addresses6(xprt, sap);
+		break;
+	default:
+		pr_err("rpcrdma: Unrecognized address family\n");
+		return;
+	}
+
+	(void)rpc_ntop(sap, buf, sizeof(buf));
+	xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
+
+	snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
+	xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
+
+	snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
+	xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
+
+	xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
+}
+
+static void
+xprt_rdma_free_addresses(struct rpc_xprt *xprt)
+{
+	unsigned int i;
+
+	for (i = 0; i < RPC_DISPLAY_MAX; i++)
+		switch (i) {
+		case RPC_DISPLAY_PROTO:
+		case RPC_DISPLAY_NETID:
+			continue;
+		default:
+			kfree(xprt->address_strings[i]);
+		}
+}
+
+static void
+xprt_rdma_connect_worker(struct work_struct *work)
+{
+	struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
+						   rx_connect_worker.work);
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
+	int rc = 0;
+
+	xprt_clear_connected(xprt);
+
+	dprintk("RPC:       %s: %sconnect\n", __func__,
+			r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
+	rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
+	if (rc)
+		xprt_wake_pending_tasks(xprt, rc);
+
+	dprintk("RPC:       %s: exit\n", __func__);
+	xprt_clear_connecting(xprt);
+}
+
+/*
+ * xprt_rdma_destroy
+ *
+ * Destroy the xprt.
+ * Free all memory associated with the object, including its own.
+ * NOTE: none of the *destroy methods free memory for their top-level
+ * objects, even though they may have allocated it (they do free
+ * private memory). It's up to the caller to handle it. In this
+ * case (RDMA transport), all structure memory is inlined with the
+ * struct rpcrdma_xprt.
+ */
+static void
+xprt_rdma_destroy(struct rpc_xprt *xprt)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+
+	dprintk("RPC:       %s: called\n", __func__);
+
+	cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
+
+	xprt_clear_connected(xprt);
+
+	rpcrdma_buffer_destroy(&r_xprt->rx_buf);
+	rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
+	rpcrdma_ia_close(&r_xprt->rx_ia);
+
+	xprt_rdma_free_addresses(xprt);
+
+	xprt_free(xprt);
+
+	dprintk("RPC:       %s: returning\n", __func__);
+
+	module_put(THIS_MODULE);
+}
+
+static const struct rpc_timeout xprt_rdma_default_timeout = {
+	.to_initval = 60 * HZ,
+	.to_maxval = 60 * HZ,
+};
+
+/**
+ * xprt_setup_rdma - Set up transport to use RDMA
+ *
+ * @args: rpc transport arguments
+ */
+static struct rpc_xprt *
+xprt_setup_rdma(struct xprt_create *args)
+{
+	struct rpcrdma_create_data_internal cdata;
+	struct rpc_xprt *xprt;
+	struct rpcrdma_xprt *new_xprt;
+	struct rpcrdma_ep *new_ep;
+	struct sockaddr_in *sin;
+	int rc;
+
+	if (args->addrlen > sizeof(xprt->addr)) {
+		dprintk("RPC:       %s: address too large\n", __func__);
+		return ERR_PTR(-EBADF);
+	}
+
+	xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
+			xprt_rdma_slot_table_entries,
+			xprt_rdma_slot_table_entries);
+	if (xprt == NULL) {
+		dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
+			__func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	/* 60 second timeout, no retries */
+	xprt->timeout = &xprt_rdma_default_timeout;
+	xprt->bind_timeout = RPCRDMA_BIND_TO;
+	xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
+	xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
+
+	xprt->resvport = 0;		/* privileged port not needed */
+	xprt->tsh_size = 0;		/* RPC-RDMA handles framing */
+	xprt->ops = &xprt_rdma_procs;
+
+	/*
+	 * Set up RDMA-specific connect data.
+	 */
+
+	/* Put server RDMA address in local cdata */
+	memcpy(&cdata.addr, args->dstaddr, args->addrlen);
+
+	/* Ensure xprt->addr holds valid server TCP (not RDMA)
+	 * address, for any side protocols which peek at it */
+	xprt->prot = IPPROTO_TCP;
+	xprt->addrlen = args->addrlen;
+	memcpy(&xprt->addr, &cdata.addr, xprt->addrlen);
+
+	sin = (struct sockaddr_in *)&cdata.addr;
+	if (ntohs(sin->sin_port) != 0)
+		xprt_set_bound(xprt);
+
+	dprintk("RPC:       %s: %pI4:%u\n",
+		__func__, &sin->sin_addr.s_addr, ntohs(sin->sin_port));
+
+	/* Set max requests */
+	cdata.max_requests = xprt->max_reqs;
+
+	/* Set some length limits */
+	cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
+	cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
+
+	cdata.inline_wsize = xprt_rdma_max_inline_write;
+	if (cdata.inline_wsize > cdata.wsize)
+		cdata.inline_wsize = cdata.wsize;
+
+	cdata.inline_rsize = xprt_rdma_max_inline_read;
+	if (cdata.inline_rsize > cdata.rsize)
+		cdata.inline_rsize = cdata.rsize;
+
+	cdata.padding = xprt_rdma_inline_write_padding;
+
+	/*
+	 * Create new transport instance, which includes initialized
+	 *  o ia
+	 *  o endpoint
+	 *  o buffers
+	 */
+
+	new_xprt = rpcx_to_rdmax(xprt);
+
+	rc = rpcrdma_ia_open(new_xprt, (struct sockaddr *) &cdata.addr,
+				xprt_rdma_memreg_strategy);
+	if (rc)
+		goto out1;
+
+	/*
+	 * initialize and create ep
+	 */
+	new_xprt->rx_data = cdata;
+	new_ep = &new_xprt->rx_ep;
+	new_ep->rep_remote_addr = cdata.addr;
+
+	rc = rpcrdma_ep_create(&new_xprt->rx_ep,
+				&new_xprt->rx_ia, &new_xprt->rx_data);
+	if (rc)
+		goto out2;
+
+	/*
+	 * Allocate pre-registered send and receive buffers for headers and
+	 * any inline data. Also specify any padding which will be provided
+	 * from a preregistered zero buffer.
+	 */
+	rc = rpcrdma_buffer_create(new_xprt);
+	if (rc)
+		goto out3;
+
+	/*
+	 * Register a callback for connection events. This is necessary because
+	 * connection loss notification is async. We also catch connection loss
+	 * when reaping receives.
+	 */
+	INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
+			  xprt_rdma_connect_worker);
+
+	xprt_rdma_format_addresses(xprt);
+	xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
+	if (xprt->max_payload == 0)
+		goto out4;
+	xprt->max_payload <<= PAGE_SHIFT;
+	dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
+		__func__, xprt->max_payload);
+
+	if (!try_module_get(THIS_MODULE))
+		goto out4;
+
+	return xprt;
+
+out4:
+	xprt_rdma_free_addresses(xprt);
+	rc = -EINVAL;
+out3:
+	rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
+out2:
+	rpcrdma_ia_close(&new_xprt->rx_ia);
+out1:
+	xprt_free(xprt);
+	return ERR_PTR(rc);
+}
+
+/*
+ * Close a connection, during shutdown or timeout/reconnect
+ */
+static void
+xprt_rdma_close(struct rpc_xprt *xprt)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+
+	dprintk("RPC:       %s: closing\n", __func__);
+	if (r_xprt->rx_ep.rep_connected > 0)
+		xprt->reestablish_timeout = 0;
+	xprt_disconnect_done(xprt);
+	rpcrdma_ep_disconnect(&r_xprt->rx_ep, &r_xprt->rx_ia);
+}
+
+static void
+xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
+{
+	struct sockaddr_in *sap;
+
+	sap = (struct sockaddr_in *)&xprt->addr;
+	sap->sin_port = htons(port);
+	sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
+	sap->sin_port = htons(port);
+	dprintk("RPC:       %s: %u\n", __func__, port);
+}
+
+static void
+xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+
+	if (r_xprt->rx_ep.rep_connected != 0) {
+		/* Reconnect */
+		schedule_delayed_work(&r_xprt->rx_connect_worker,
+				      xprt->reestablish_timeout);
+		xprt->reestablish_timeout <<= 1;
+		if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
+			xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
+		else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
+			xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
+	} else {
+		schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
+		if (!RPC_IS_ASYNC(task))
+			flush_delayed_work(&r_xprt->rx_connect_worker);
+	}
+}
+
+/*
+ * The RDMA allocate/free functions need the task structure as a place
+ * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
+ * sequence.
+ *
+ * The RPC layer allocates both send and receive buffers in the same call
+ * (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
+ * We may register rq_rcv_buf when using reply chunks.
+ */
+static void *
+xprt_rdma_allocate(struct rpc_task *task, size_t size)
+{
+	struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_regbuf *rb;
+	struct rpcrdma_req *req;
+	size_t min_size;
+	gfp_t flags;
+
+	req = rpcrdma_buffer_get(&r_xprt->rx_buf);
+	if (req == NULL)
+		return NULL;
+
+	flags = GFP_NOIO | __GFP_NOWARN;
+	if (RPC_IS_SWAPPER(task))
+		flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
+
+	if (req->rl_rdmabuf == NULL)
+		goto out_rdmabuf;
+	if (req->rl_sendbuf == NULL)
+		goto out_sendbuf;
+	if (size > req->rl_sendbuf->rg_size)
+		goto out_sendbuf;
+
+out:
+	dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
+	req->rl_connect_cookie = 0;	/* our reserved value */
+	return req->rl_sendbuf->rg_base;
+
+out_rdmabuf:
+	min_size = RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
+	rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, min_size, flags);
+	if (IS_ERR(rb))
+		goto out_fail;
+	req->rl_rdmabuf = rb;
+
+out_sendbuf:
+	/* XDR encoding and RPC/RDMA marshaling of this request has not
+	 * yet occurred. Thus a lower bound is needed to prevent buffer
+	 * overrun during marshaling.
+	 *
+	 * RPC/RDMA marshaling may choose to send payload bearing ops
+	 * inline, if the result is smaller than the inline threshold.
+	 * The value of the "size" argument accounts for header
+	 * requirements but not for the payload in these cases.
+	 *
+	 * Likewise, allocate enough space to receive a reply up to the
+	 * size of the inline threshold.
+	 *
+	 * It's unlikely that both the send header and the received
+	 * reply will be large, but slush is provided here to allow
+	 * flexibility when marshaling.
+	 */
+	min_size = RPCRDMA_INLINE_READ_THRESHOLD(task->tk_rqstp);
+	min_size += RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
+	if (size < min_size)
+		size = min_size;
+
+	rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags);
+	if (IS_ERR(rb))
+		goto out_fail;
+	rb->rg_owner = req;
+
+	r_xprt->rx_stats.hardway_register_count += size;
+	rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
+	req->rl_sendbuf = rb;
+	goto out;
+
+out_fail:
+	rpcrdma_buffer_put(req);
+	r_xprt->rx_stats.failed_marshal_count++;
+	return NULL;
+}
+
+/*
+ * This function returns all RDMA resources to the pool.
+ */
+static void
+xprt_rdma_free(void *buffer)
+{
+	struct rpcrdma_req *req;
+	struct rpcrdma_xprt *r_xprt;
+	struct rpcrdma_regbuf *rb;
+	int i;
+
+	if (buffer == NULL)
+		return;
+
+	rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
+	req = rb->rg_owner;
+	r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
+
+	dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
+
+	for (i = 0; req->rl_nchunks;) {
+		--req->rl_nchunks;
+		i += r_xprt->rx_ia.ri_ops->ro_unmap(r_xprt,
+						    &req->rl_segments[i]);
+	}
+
+	rpcrdma_buffer_put(req);
+}
+
+/*
+ * send_request invokes the meat of RPC RDMA. It must do the following:
+ *  1.  Marshal the RPC request into an RPC RDMA request, which means
+ *	putting a header in front of data, and creating IOVs for RDMA
+ *	from those in the request.
+ *  2.  In marshaling, detect opportunities for RDMA, and use them.
+ *  3.  Post a recv message to set up asynch completion, then send
+ *	the request (rpcrdma_ep_post).
+ *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
+ */
+
+static int
+xprt_rdma_send_request(struct rpc_task *task)
+{
+	struct rpc_rqst *rqst = task->tk_rqstp;
+	struct rpc_xprt *xprt = rqst->rq_xprt;
+	struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	int rc = 0;
+
+	rc = rpcrdma_marshal_req(rqst);
+	if (rc < 0)
+		goto failed_marshal;
+
+	if (req->rl_reply == NULL) 		/* e.g. reconnection */
+		rpcrdma_recv_buffer_get(req);
+
+	if (req->rl_reply) {
+		req->rl_reply->rr_func = rpcrdma_reply_handler;
+		/* this need only be done once, but... */
+		req->rl_reply->rr_xprt = xprt;
+	}
+
+	/* Must suppress retransmit to maintain credits */
+	if (req->rl_connect_cookie == xprt->connect_cookie)
+		goto drop_connection;
+	req->rl_connect_cookie = xprt->connect_cookie;
+
+	if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
+		goto drop_connection;
+
+	rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
+	rqst->rq_bytes_sent = 0;
+	return 0;
+
+failed_marshal:
+	r_xprt->rx_stats.failed_marshal_count++;
+	dprintk("RPC:       %s: rpcrdma_marshal_req failed, status %i\n",
+		__func__, rc);
+	if (rc == -EIO)
+		return -EIO;
+drop_connection:
+	xprt_disconnect_done(xprt);
+	return -ENOTCONN;	/* implies disconnect */
+}
+
+static void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
+{
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	long idle_time = 0;
+
+	if (xprt_connected(xprt))
+		idle_time = (long)(jiffies - xprt->last_used) / HZ;
+
+	seq_printf(seq,
+	  "\txprt:\trdma %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu "
+	  "%lu %lu %lu %Lu %Lu %Lu %Lu %lu %lu %lu\n",
+
+	   0,	/* need a local port? */
+	   xprt->stat.bind_count,
+	   xprt->stat.connect_count,
+	   xprt->stat.connect_time,
+	   idle_time,
+	   xprt->stat.sends,
+	   xprt->stat.recvs,
+	   xprt->stat.bad_xids,
+	   xprt->stat.req_u,
+	   xprt->stat.bklog_u,
+
+	   r_xprt->rx_stats.read_chunk_count,
+	   r_xprt->rx_stats.write_chunk_count,
+	   r_xprt->rx_stats.reply_chunk_count,
+	   r_xprt->rx_stats.total_rdma_request,
+	   r_xprt->rx_stats.total_rdma_reply,
+	   r_xprt->rx_stats.pullup_copy_count,
+	   r_xprt->rx_stats.fixup_copy_count,
+	   r_xprt->rx_stats.hardway_register_count,
+	   r_xprt->rx_stats.failed_marshal_count,
+	   r_xprt->rx_stats.bad_reply_count);
+}
+
+/*
+ * Plumbing for rpc transport switch and kernel module
+ */
+
+static struct rpc_xprt_ops xprt_rdma_procs = {
+	.reserve_xprt		= xprt_reserve_xprt_cong,
+	.release_xprt		= xprt_release_xprt_cong, /* sunrpc/xprt.c */
+	.alloc_slot		= xprt_alloc_slot,
+	.release_request	= xprt_release_rqst_cong,       /* ditto */
+	.set_retrans_timeout	= xprt_set_retrans_timeout_def, /* ditto */
+	.rpcbind		= rpcb_getport_async,	/* sunrpc/rpcb_clnt.c */
+	.set_port		= xprt_rdma_set_port,
+	.connect		= xprt_rdma_connect,
+	.buf_alloc		= xprt_rdma_allocate,
+	.buf_free		= xprt_rdma_free,
+	.send_request		= xprt_rdma_send_request,
+	.close			= xprt_rdma_close,
+	.destroy		= xprt_rdma_destroy,
+	.print_stats		= xprt_rdma_print_stats
+};
+
+static struct xprt_class xprt_rdma = {
+	.list			= LIST_HEAD_INIT(xprt_rdma.list),
+	.name			= "rdma",
+	.owner			= THIS_MODULE,
+	.ident			= XPRT_TRANSPORT_RDMA,
+	.setup			= xprt_setup_rdma,
+};
+
+static void __exit xprt_rdma_cleanup(void)
+{
+	int rc;
+
+	dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+	if (sunrpc_table_header) {
+		unregister_sysctl_table(sunrpc_table_header);
+		sunrpc_table_header = NULL;
+	}
+#endif
+	rc = xprt_unregister_transport(&xprt_rdma);
+	if (rc)
+		dprintk("RPC:       %s: xprt_unregister returned %i\n",
+			__func__, rc);
+}
+
+static int __init xprt_rdma_init(void)
+{
+	int rc;
+
+	rc = xprt_register_transport(&xprt_rdma);
+
+	if (rc)
+		return rc;
+
+	dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
+
+	dprintk("Defaults:\n");
+	dprintk("\tSlots %d\n"
+		"\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
+		xprt_rdma_slot_table_entries,
+		xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
+	dprintk("\tPadding %d\n\tMemreg %d\n",
+		xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
+
+#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
+	if (!sunrpc_table_header)
+		sunrpc_table_header = register_sysctl_table(sunrpc_table);
+#endif
+	return 0;
+}
+
+module_init(xprt_rdma_init);
+module_exit(xprt_rdma_cleanup);