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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /net/sunrpc/xprtrdma/xprt_rdma.h
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/sunrpc/xprtrdma/xprt_rdma.h')
-rw-r--r--net/sunrpc/xprtrdma/xprt_rdma.h604
1 files changed, 604 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
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+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -0,0 +1,604 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * Copyright (c) 2014-2017 Oracle. All rights reserved.
+ * 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.
+ */
+
+#ifndef _LINUX_SUNRPC_XPRT_RDMA_H
+#define _LINUX_SUNRPC_XPRT_RDMA_H
+
+#include <linux/wait.h> /* wait_queue_head_t, etc */
+#include <linux/spinlock.h> /* spinlock_t, etc */
+#include <linux/atomic.h> /* atomic_t, etc */
+#include <linux/kref.h> /* struct kref */
+#include <linux/workqueue.h> /* struct work_struct */
+#include <linux/llist.h>
+
+#include <rdma/rdma_cm.h> /* RDMA connection api */
+#include <rdma/ib_verbs.h> /* RDMA verbs api */
+
+#include <linux/sunrpc/clnt.h> /* rpc_xprt */
+#include <linux/sunrpc/rpc_rdma_cid.h> /* completion IDs */
+#include <linux/sunrpc/rpc_rdma.h> /* RPC/RDMA protocol */
+#include <linux/sunrpc/xprtrdma.h> /* xprt parameters */
+
+#define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */
+#define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */
+
+#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)
+
+/*
+ * RDMA Endpoint -- connection endpoint details
+ */
+struct rpcrdma_mr;
+struct rpcrdma_ep {
+ struct kref re_kref;
+ struct rdma_cm_id *re_id;
+ struct ib_pd *re_pd;
+ unsigned int re_max_rdma_segs;
+ unsigned int re_max_fr_depth;
+ struct rpcrdma_mr *re_write_pad_mr;
+ enum ib_mr_type re_mrtype;
+ struct completion re_done;
+ unsigned int re_send_count;
+ unsigned int re_send_batch;
+ unsigned int re_max_inline_send;
+ unsigned int re_max_inline_recv;
+ int re_async_rc;
+ int re_connect_status;
+ atomic_t re_receiving;
+ atomic_t re_force_disconnect;
+ struct ib_qp_init_attr re_attr;
+ wait_queue_head_t re_connect_wait;
+ struct rpc_xprt *re_xprt;
+ struct rpcrdma_connect_private
+ re_cm_private;
+ struct rdma_conn_param re_remote_cma;
+ int re_receive_count;
+ unsigned int re_max_requests; /* depends on device */
+ unsigned int re_inline_send; /* negotiated */
+ unsigned int re_inline_recv; /* negotiated */
+
+ atomic_t re_completion_ids;
+
+ char re_write_pad[XDR_UNIT];
+};
+
+/* Pre-allocate extra Work Requests for handling reverse-direction
+ * Receives and Sends. This is a fixed value because the Work Queues
+ * are allocated when the forward channel is set up, long before the
+ * backchannel is provisioned. This value is two times
+ * NFS4_DEF_CB_SLOT_TABLE_SIZE.
+ */
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+#define RPCRDMA_BACKWARD_WRS (32)
+#else
+#define RPCRDMA_BACKWARD_WRS (0)
+#endif
+
+/* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
+ */
+
+struct rpcrdma_regbuf {
+ struct ib_sge rg_iov;
+ struct ib_device *rg_device;
+ enum dma_data_direction rg_direction;
+ void *rg_data;
+};
+
+static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
+{
+ return rb->rg_iov.addr;
+}
+
+static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
+{
+ return rb->rg_iov.length;
+}
+
+static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
+{
+ return rb->rg_iov.lkey;
+}
+
+static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
+{
+ return rb->rg_device;
+}
+
+static inline void *rdmab_data(const struct rpcrdma_regbuf *rb)
+{
+ return rb->rg_data;
+}
+
+/* Do not use emergency memory reserves, and fail quickly if memory
+ * cannot be allocated easily. These flags may be used wherever there
+ * is robust logic to handle a failure to allocate.
+ */
+#define XPRTRDMA_GFP_FLAGS (__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN)
+
+/* To ensure a transport can always make forward progress,
+ * the number of RDMA segments allowed in header chunk lists
+ * is capped at 16. This prevents less-capable devices from
+ * overrunning the Send buffer while building chunk lists.
+ *
+ * Elements of the Read list take up more room than the
+ * Write list or Reply chunk. 16 read segments means the
+ * chunk lists cannot consume more than
+ *
+ * ((16 + 2) * read segment size) + 1 XDR words,
+ *
+ * or about 400 bytes. The fixed part of the header is
+ * another 24 bytes. Thus when the inline threshold is
+ * 1024 bytes, at least 600 bytes are available for RPC
+ * message bodies.
+ */
+enum {
+ RPCRDMA_MAX_HDR_SEGS = 16,
+};
+
+/*
+ * struct rpcrdma_rep -- this structure encapsulates state required
+ * to receive and complete an RPC Reply, asychronously. It needs
+ * several pieces of state:
+ *
+ * o receive buffer and ib_sge (donated to provider)
+ * o status of receive (success or not, length, inv rkey)
+ * o bookkeeping state to get run by reply handler (XDR stream)
+ *
+ * These structures are allocated during transport initialization.
+ * N of these are associated with a transport instance, managed by
+ * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
+ */
+
+struct rpcrdma_rep {
+ struct ib_cqe rr_cqe;
+ struct rpc_rdma_cid rr_cid;
+
+ __be32 rr_xid;
+ __be32 rr_vers;
+ __be32 rr_proc;
+ int rr_wc_flags;
+ u32 rr_inv_rkey;
+ bool rr_temp;
+ struct rpcrdma_regbuf *rr_rdmabuf;
+ struct rpcrdma_xprt *rr_rxprt;
+ struct rpc_rqst *rr_rqst;
+ struct xdr_buf rr_hdrbuf;
+ struct xdr_stream rr_stream;
+ struct llist_node rr_node;
+ struct ib_recv_wr rr_recv_wr;
+ struct list_head rr_all;
+};
+
+/* To reduce the rate at which a transport invokes ib_post_recv
+ * (and thus the hardware doorbell rate), xprtrdma posts Receive
+ * WRs in batches.
+ *
+ * Setting this to zero disables Receive post batching.
+ */
+enum {
+ RPCRDMA_MAX_RECV_BATCH = 7,
+};
+
+/* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
+ */
+struct rpcrdma_req;
+struct rpcrdma_sendctx {
+ struct ib_cqe sc_cqe;
+ struct rpc_rdma_cid sc_cid;
+ struct rpcrdma_req *sc_req;
+ unsigned int sc_unmap_count;
+ struct ib_sge sc_sges[];
+};
+
+/*
+ * struct rpcrdma_mr - external memory region metadata
+ *
+ * An external memory region is any buffer or page that is registered
+ * on the fly (ie, not pre-registered).
+ */
+struct rpcrdma_req;
+struct rpcrdma_mr {
+ struct list_head mr_list;
+ struct rpcrdma_req *mr_req;
+
+ struct ib_mr *mr_ibmr;
+ struct ib_device *mr_device;
+ struct scatterlist *mr_sg;
+ int mr_nents;
+ enum dma_data_direction mr_dir;
+ struct ib_cqe mr_cqe;
+ struct completion mr_linv_done;
+ union {
+ struct ib_reg_wr mr_regwr;
+ struct ib_send_wr mr_invwr;
+ };
+ struct rpcrdma_xprt *mr_xprt;
+ u32 mr_handle;
+ u32 mr_length;
+ u64 mr_offset;
+ struct list_head mr_all;
+ struct rpc_rdma_cid mr_cid;
+};
+
+/*
+ * struct rpcrdma_req -- structure central to the request/reply sequence.
+ *
+ * N of these are associated with a transport instance, and stored in
+ * struct rpcrdma_buffer. N is the max number of outstanding requests.
+ *
+ * It includes pre-registered buffer memory for send AND recv.
+ * The recv buffer, however, is not owned by this structure, and
+ * is "donated" to the hardware when a recv is posted. When a
+ * reply is handled, the recv buffer used is given back to the
+ * struct rpcrdma_req associated with the request.
+ *
+ * In addition to the basic memory, this structure includes an array
+ * of iovs for send operations. The reason is that the iovs passed to
+ * ib_post_{send,recv} must not be modified until the work request
+ * completes.
+ */
+
+/* Maximum number of page-sized "segments" per chunk list to be
+ * registered or invalidated. Must handle a Reply chunk:
+ */
+enum {
+ RPCRDMA_MAX_IOV_SEGS = 3,
+ RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
+ RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS +
+ RPCRDMA_MAX_IOV_SEGS,
+};
+
+/* Arguments for DMA mapping and registration */
+struct rpcrdma_mr_seg {
+ u32 mr_len; /* length of segment */
+ struct page *mr_page; /* underlying struct page */
+ u64 mr_offset; /* IN: page offset, OUT: iova */
+};
+
+/* The Send SGE array is provisioned to send a maximum size
+ * inline request:
+ * - RPC-over-RDMA header
+ * - xdr_buf head iovec
+ * - RPCRDMA_MAX_INLINE bytes, in pages
+ * - xdr_buf tail iovec
+ *
+ * The actual number of array elements consumed by each RPC
+ * depends on the device's max_sge limit.
+ */
+enum {
+ RPCRDMA_MIN_SEND_SGES = 3,
+ RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
+ RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
+};
+
+struct rpcrdma_buffer;
+struct rpcrdma_req {
+ struct list_head rl_list;
+ struct rpc_rqst rl_slot;
+ struct rpcrdma_rep *rl_reply;
+ struct xdr_stream rl_stream;
+ struct xdr_buf rl_hdrbuf;
+ struct ib_send_wr rl_wr;
+ struct rpcrdma_sendctx *rl_sendctx;
+ struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */
+ struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */
+ struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */
+
+ struct list_head rl_all;
+ struct kref rl_kref;
+
+ struct list_head rl_free_mrs;
+ struct list_head rl_registered;
+ struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];
+};
+
+static inline struct rpcrdma_req *
+rpcr_to_rdmar(const struct rpc_rqst *rqst)
+{
+ return container_of(rqst, struct rpcrdma_req, rl_slot);
+}
+
+static inline void
+rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
+{
+ list_add(&mr->mr_list, list);
+}
+
+static inline struct rpcrdma_mr *
+rpcrdma_mr_pop(struct list_head *list)
+{
+ struct rpcrdma_mr *mr;
+
+ mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list);
+ if (mr)
+ list_del_init(&mr->mr_list);
+ return mr;
+}
+
+/*
+ * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
+ * inline requests/replies, and client/server credits.
+ *
+ * One of these is associated with a transport instance
+ */
+struct rpcrdma_buffer {
+ spinlock_t rb_lock;
+ struct list_head rb_send_bufs;
+ struct list_head rb_mrs;
+
+ unsigned long rb_sc_head;
+ unsigned long rb_sc_tail;
+ unsigned long rb_sc_last;
+ struct rpcrdma_sendctx **rb_sc_ctxs;
+
+ struct list_head rb_allreqs;
+ struct list_head rb_all_mrs;
+ struct list_head rb_all_reps;
+
+ struct llist_head rb_free_reps;
+
+ __be32 rb_max_requests;
+ u32 rb_credits; /* most recent credit grant */
+
+ u32 rb_bc_srv_max_requests;
+ u32 rb_bc_max_requests;
+
+ struct work_struct rb_refresh_worker;
+};
+
+/*
+ * Statistics for RPCRDMA
+ */
+struct rpcrdma_stats {
+ /* accessed when sending a call */
+ unsigned long read_chunk_count;
+ unsigned long write_chunk_count;
+ unsigned long reply_chunk_count;
+ unsigned long long total_rdma_request;
+
+ /* rarely accessed error counters */
+ unsigned long long pullup_copy_count;
+ unsigned long hardway_register_count;
+ unsigned long failed_marshal_count;
+ unsigned long bad_reply_count;
+ unsigned long mrs_recycled;
+ unsigned long mrs_orphaned;
+ unsigned long mrs_allocated;
+ unsigned long empty_sendctx_q;
+
+ /* accessed when receiving a reply */
+ unsigned long long total_rdma_reply;
+ unsigned long long fixup_copy_count;
+ unsigned long reply_waits_for_send;
+ unsigned long local_inv_needed;
+ unsigned long nomsg_call_count;
+ unsigned long bcall_count;
+};
+
+/*
+ * RPCRDMA transport -- encapsulates the structures above for
+ * integration with RPC.
+ *
+ * The contained structures are embedded, not pointers,
+ * for convenience. This structure need not be visible externally.
+ *
+ * It is allocated and initialized during mount, and released
+ * during unmount.
+ */
+struct rpcrdma_xprt {
+ struct rpc_xprt rx_xprt;
+ struct rpcrdma_ep *rx_ep;
+ struct rpcrdma_buffer rx_buf;
+ struct delayed_work rx_connect_worker;
+ struct rpc_timeout rx_timeout;
+ struct rpcrdma_stats rx_stats;
+};
+
+#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
+
+static inline const char *
+rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
+{
+ return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
+}
+
+static inline const char *
+rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
+{
+ return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
+}
+
+/* Setting this to 0 ensures interoperability with early servers.
+ * Setting this to 1 enhances certain unaligned read/write performance.
+ * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
+extern int xprt_rdma_pad_optimize;
+
+/* This setting controls the hunt for a supported memory
+ * registration strategy.
+ */
+extern unsigned int xprt_rdma_memreg_strategy;
+
+/*
+ * Endpoint calls - xprtrdma/verbs.c
+ */
+void rpcrdma_force_disconnect(struct rpcrdma_ep *ep);
+void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc);
+int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt);
+void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt);
+
+void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp);
+
+/*
+ * Buffer calls - xprtrdma/verbs.c
+ */
+struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt,
+ size_t size);
+int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
+void rpcrdma_req_destroy(struct rpcrdma_req *req);
+int rpcrdma_buffer_create(struct rpcrdma_xprt *);
+void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
+struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
+
+struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
+void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
+
+struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
+void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
+ struct rpcrdma_req *req);
+void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep);
+void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req);
+
+bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
+ gfp_t flags);
+bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
+ struct rpcrdma_regbuf *rb);
+
+/**
+ * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped
+ *
+ * Returns true if the buffer is now mapped to rb->rg_device.
+ */
+static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
+{
+ return rb->rg_device != NULL;
+}
+
+/**
+ * rpcrdma_regbuf_dma_map - DMA-map a regbuf
+ * @r_xprt: controlling transport instance
+ * @rb: regbuf to be mapped
+ *
+ * Returns true if the buffer is currently DMA mapped.
+ */
+static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
+ struct rpcrdma_regbuf *rb)
+{
+ if (likely(rpcrdma_regbuf_is_mapped(rb)))
+ return true;
+ return __rpcrdma_regbuf_dma_map(r_xprt, rb);
+}
+
+/*
+ * Wrappers for chunk registration, shared by read/write chunk code.
+ */
+
+static inline enum dma_data_direction
+rpcrdma_data_dir(bool writing)
+{
+ return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+}
+
+/* Memory registration calls xprtrdma/frwr_ops.c
+ */
+void frwr_reset(struct rpcrdma_req *req);
+int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device);
+int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr);
+void frwr_mr_release(struct rpcrdma_mr *mr);
+struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
+ struct rpcrdma_mr_seg *seg,
+ int nsegs, bool writing, __be32 xid,
+ struct rpcrdma_mr *mr);
+int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
+void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
+void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
+void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
+int frwr_wp_create(struct rpcrdma_xprt *r_xprt);
+
+/*
+ * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
+ */
+
+enum rpcrdma_chunktype {
+ rpcrdma_noch = 0,
+ rpcrdma_noch_pullup,
+ rpcrdma_noch_mapped,
+ rpcrdma_readch,
+ rpcrdma_areadch,
+ rpcrdma_writech,
+ rpcrdma_replych
+};
+
+int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
+ struct rpcrdma_req *req, u32 hdrlen,
+ struct xdr_buf *xdr,
+ enum rpcrdma_chunktype rtype);
+void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
+int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
+void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep);
+void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
+void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
+void rpcrdma_unpin_rqst(struct rpcrdma_rep *rep);
+void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
+
+static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
+{
+ xdr->head[0].iov_len = len;
+ xdr->len = len;
+}
+
+/* RPC/RDMA module init - xprtrdma/transport.c
+ */
+extern unsigned int xprt_rdma_max_inline_read;
+extern unsigned int xprt_rdma_max_inline_write;
+void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
+void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
+void xprt_rdma_close(struct rpc_xprt *xprt);
+void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
+int xprt_rdma_init(void);
+void xprt_rdma_cleanup(void);
+
+/* Backchannel calls - xprtrdma/backchannel.c
+ */
+#if defined(CONFIG_SUNRPC_BACKCHANNEL)
+int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
+size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
+unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
+void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
+int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
+void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
+void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
+
+extern struct xprt_class xprt_rdma_bc;
+
+#endif /* _LINUX_SUNRPC_XPRT_RDMA_H */