v4.19.13 snapshot.
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
new file mode 100644
index 0000000..fd78f78
--- /dev/null
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -0,0 +1,206 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * Copyright (c) 2005-2006 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.
+ *
+ * Author: Tom Tucker <tom@opengridcomputing.com>
+ */
+
+#ifndef SVC_RDMA_H
+#define SVC_RDMA_H
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/rpc_rdma.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#define SVCRDMA_DEBUG
+
+/* Default and maximum inline threshold sizes */
+enum {
+	RPCRDMA_DEF_INLINE_THRESH = 4096,
+	RPCRDMA_MAX_INLINE_THRESH = 65536
+};
+
+/* RPC/RDMA parameters and stats */
+extern unsigned int svcrdma_ord;
+extern unsigned int svcrdma_max_requests;
+extern unsigned int svcrdma_max_bc_requests;
+extern unsigned int svcrdma_max_req_size;
+
+extern atomic_t rdma_stat_recv;
+extern atomic_t rdma_stat_read;
+extern atomic_t rdma_stat_write;
+extern atomic_t rdma_stat_sq_starve;
+extern atomic_t rdma_stat_rq_starve;
+extern atomic_t rdma_stat_rq_poll;
+extern atomic_t rdma_stat_rq_prod;
+extern atomic_t rdma_stat_sq_poll;
+extern atomic_t rdma_stat_sq_prod;
+
+struct svcxprt_rdma {
+	struct svc_xprt      sc_xprt;		/* SVC transport structure */
+	struct rdma_cm_id    *sc_cm_id;		/* RDMA connection id */
+	struct list_head     sc_accept_q;	/* Conn. waiting accept */
+	int		     sc_ord;		/* RDMA read limit */
+	int                  sc_max_send_sges;
+	bool		     sc_snd_w_inv;	/* OK to use Send With Invalidate */
+
+	atomic_t             sc_sq_avail;	/* SQEs ready to be consumed */
+	unsigned int	     sc_sq_depth;	/* Depth of SQ */
+	__be32		     sc_fc_credits;	/* Forward credits */
+	u32		     sc_max_requests;	/* Max requests */
+	u32		     sc_max_bc_requests;/* Backward credits */
+	int                  sc_max_req_size;	/* Size of each RQ WR buf */
+	u8		     sc_port_num;
+
+	struct ib_pd         *sc_pd;
+
+	spinlock_t	     sc_send_lock;
+	struct list_head     sc_send_ctxts;
+	spinlock_t	     sc_rw_ctxt_lock;
+	struct list_head     sc_rw_ctxts;
+
+	struct list_head     sc_rq_dto_q;
+	spinlock_t	     sc_rq_dto_lock;
+	struct ib_qp         *sc_qp;
+	struct ib_cq         *sc_rq_cq;
+	struct ib_cq         *sc_sq_cq;
+
+	spinlock_t	     sc_lock;		/* transport lock */
+
+	wait_queue_head_t    sc_send_wait;	/* SQ exhaustion waitlist */
+	unsigned long	     sc_flags;
+	struct list_head     sc_read_complete_q;
+	struct work_struct   sc_work;
+
+	spinlock_t	     sc_recv_lock;
+	struct list_head     sc_recv_ctxts;
+};
+/* sc_flags */
+#define RDMAXPRT_CONN_PENDING	3
+
+#define RPCRDMA_LISTEN_BACKLOG  10
+#define RPCRDMA_MAX_REQUESTS    32
+
+/* Typical ULP usage of BC requests is NFSv4.1 backchannel. Our
+ * current NFSv4.1 implementation supports one backchannel slot.
+ */
+#define RPCRDMA_MAX_BC_REQUESTS	2
+
+#define RPCSVC_MAXPAYLOAD_RDMA	RPCSVC_MAXPAYLOAD
+
+struct svc_rdma_recv_ctxt {
+	struct list_head	rc_list;
+	struct ib_recv_wr	rc_recv_wr;
+	struct ib_cqe		rc_cqe;
+	struct ib_sge		rc_recv_sge;
+	void			*rc_recv_buf;
+	struct xdr_buf		rc_arg;
+	bool			rc_temp;
+	u32			rc_byte_len;
+	unsigned int		rc_page_count;
+	unsigned int		rc_hdr_count;
+	struct page		*rc_pages[RPCSVC_MAXPAGES];
+};
+
+struct svc_rdma_send_ctxt {
+	struct list_head	sc_list;
+	struct ib_send_wr	sc_send_wr;
+	struct ib_cqe		sc_cqe;
+	void			*sc_xprt_buf;
+	int			sc_page_count;
+	int			sc_cur_sge_no;
+	struct page		*sc_pages[RPCSVC_MAXPAGES];
+	struct ib_sge		sc_sges[];
+};
+
+/* svc_rdma_backchannel.c */
+extern int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt,
+				    __be32 *rdma_resp,
+				    struct xdr_buf *rcvbuf);
+
+/* svc_rdma_recvfrom.c */
+extern void svc_rdma_recv_ctxts_destroy(struct svcxprt_rdma *rdma);
+extern bool svc_rdma_post_recvs(struct svcxprt_rdma *rdma);
+extern void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma,
+				   struct svc_rdma_recv_ctxt *ctxt);
+extern void svc_rdma_flush_recv_queues(struct svcxprt_rdma *rdma);
+extern int svc_rdma_recvfrom(struct svc_rqst *);
+
+/* svc_rdma_rw.c */
+extern void svc_rdma_destroy_rw_ctxts(struct svcxprt_rdma *rdma);
+extern int svc_rdma_recv_read_chunk(struct svcxprt_rdma *rdma,
+				    struct svc_rqst *rqstp,
+				    struct svc_rdma_recv_ctxt *head, __be32 *p);
+extern int svc_rdma_send_write_chunk(struct svcxprt_rdma *rdma,
+				     __be32 *wr_ch, struct xdr_buf *xdr);
+extern int svc_rdma_send_reply_chunk(struct svcxprt_rdma *rdma,
+				     __be32 *rp_ch, bool writelist,
+				     struct xdr_buf *xdr);
+
+/* svc_rdma_sendto.c */
+extern void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma);
+extern struct svc_rdma_send_ctxt *
+		svc_rdma_send_ctxt_get(struct svcxprt_rdma *rdma);
+extern void svc_rdma_send_ctxt_put(struct svcxprt_rdma *rdma,
+				   struct svc_rdma_send_ctxt *ctxt);
+extern int svc_rdma_send(struct svcxprt_rdma *rdma, struct ib_send_wr *wr);
+extern void svc_rdma_sync_reply_hdr(struct svcxprt_rdma *rdma,
+				    struct svc_rdma_send_ctxt *ctxt,
+				    unsigned int len);
+extern int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
+				  struct svc_rdma_send_ctxt *ctxt,
+				  struct xdr_buf *xdr, __be32 *wr_lst);
+extern int svc_rdma_sendto(struct svc_rqst *);
+
+/* svc_rdma_transport.c */
+extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
+extern void svc_sq_reap(struct svcxprt_rdma *);
+extern void svc_rq_reap(struct svcxprt_rdma *);
+extern void svc_rdma_prep_reply_hdr(struct svc_rqst *);
+
+extern struct svc_xprt_class svc_rdma_class;
+#ifdef CONFIG_SUNRPC_BACKCHANNEL
+extern struct svc_xprt_class svc_rdma_bc_class;
+#endif
+
+/* svc_rdma.c */
+extern struct workqueue_struct *svc_rdma_wq;
+extern int svc_rdma_init(void);
+extern void svc_rdma_cleanup(void);
+
+#endif