cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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xprt_rdma.h (18704B)


      1/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
      2/*
      3 * Copyright (c) 2014-2017 Oracle.  All rights reserved.
      4 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
      5 *
      6 * This software is available to you under a choice of one of two
      7 * licenses.  You may choose to be licensed under the terms of the GNU
      8 * General Public License (GPL) Version 2, available from the file
      9 * COPYING in the main directory of this source tree, or the BSD-type
     10 * license below:
     11 *
     12 * Redistribution and use in source and binary forms, with or without
     13 * modification, are permitted provided that the following conditions
     14 * are met:
     15 *
     16 *      Redistributions of source code must retain the above copyright
     17 *      notice, this list of conditions and the following disclaimer.
     18 *
     19 *      Redistributions in binary form must reproduce the above
     20 *      copyright notice, this list of conditions and the following
     21 *      disclaimer in the documentation and/or other materials provided
     22 *      with the distribution.
     23 *
     24 *      Neither the name of the Network Appliance, Inc. nor the names of
     25 *      its contributors may be used to endorse or promote products
     26 *      derived from this software without specific prior written
     27 *      permission.
     28 *
     29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     40 */
     41
     42#ifndef _LINUX_SUNRPC_XPRT_RDMA_H
     43#define _LINUX_SUNRPC_XPRT_RDMA_H
     44
     45#include <linux/wait.h> 		/* wait_queue_head_t, etc */
     46#include <linux/spinlock.h> 		/* spinlock_t, etc */
     47#include <linux/atomic.h>		/* atomic_t, etc */
     48#include <linux/kref.h>			/* struct kref */
     49#include <linux/workqueue.h>		/* struct work_struct */
     50#include <linux/llist.h>
     51
     52#include <rdma/rdma_cm.h>		/* RDMA connection api */
     53#include <rdma/ib_verbs.h>		/* RDMA verbs api */
     54
     55#include <linux/sunrpc/clnt.h> 		/* rpc_xprt */
     56#include <linux/sunrpc/rpc_rdma_cid.h> 	/* completion IDs */
     57#include <linux/sunrpc/rpc_rdma.h> 	/* RPC/RDMA protocol */
     58#include <linux/sunrpc/xprtrdma.h> 	/* xprt parameters */
     59
     60#define RDMA_RESOLVE_TIMEOUT	(5000)	/* 5 seconds */
     61#define RDMA_CONNECT_RETRY_MAX	(2)	/* retries if no listener backlog */
     62
     63#define RPCRDMA_BIND_TO		(60U * HZ)
     64#define RPCRDMA_INIT_REEST_TO	(5U * HZ)
     65#define RPCRDMA_MAX_REEST_TO	(30U * HZ)
     66#define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
     67
     68/*
     69 * RDMA Endpoint -- connection endpoint details
     70 */
     71struct rpcrdma_mr;
     72struct rpcrdma_ep {
     73	struct kref		re_kref;
     74	struct rdma_cm_id 	*re_id;
     75	struct ib_pd		*re_pd;
     76	unsigned int		re_max_rdma_segs;
     77	unsigned int		re_max_fr_depth;
     78	struct rpcrdma_mr	*re_write_pad_mr;
     79	enum ib_mr_type		re_mrtype;
     80	struct completion	re_done;
     81	unsigned int		re_send_count;
     82	unsigned int		re_send_batch;
     83	unsigned int		re_max_inline_send;
     84	unsigned int		re_max_inline_recv;
     85	int			re_async_rc;
     86	int			re_connect_status;
     87	atomic_t		re_receiving;
     88	atomic_t		re_force_disconnect;
     89	struct ib_qp_init_attr	re_attr;
     90	wait_queue_head_t       re_connect_wait;
     91	struct rpc_xprt		*re_xprt;
     92	struct rpcrdma_connect_private
     93				re_cm_private;
     94	struct rdma_conn_param	re_remote_cma;
     95	int			re_receive_count;
     96	unsigned int		re_max_requests; /* depends on device */
     97	unsigned int		re_inline_send;	/* negotiated */
     98	unsigned int		re_inline_recv;	/* negotiated */
     99
    100	atomic_t		re_completion_ids;
    101
    102	char			re_write_pad[XDR_UNIT];
    103};
    104
    105/* Pre-allocate extra Work Requests for handling reverse-direction
    106 * Receives and Sends. This is a fixed value because the Work Queues
    107 * are allocated when the forward channel is set up, long before the
    108 * backchannel is provisioned. This value is two times
    109 * NFS4_DEF_CB_SLOT_TABLE_SIZE.
    110 */
    111#if defined(CONFIG_SUNRPC_BACKCHANNEL)
    112#define RPCRDMA_BACKWARD_WRS (32)
    113#else
    114#define RPCRDMA_BACKWARD_WRS (0)
    115#endif
    116
    117/* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
    118 */
    119
    120struct rpcrdma_regbuf {
    121	struct ib_sge		rg_iov;
    122	struct ib_device	*rg_device;
    123	enum dma_data_direction	rg_direction;
    124	void			*rg_data;
    125};
    126
    127static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
    128{
    129	return rb->rg_iov.addr;
    130}
    131
    132static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
    133{
    134	return rb->rg_iov.length;
    135}
    136
    137static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
    138{
    139	return rb->rg_iov.lkey;
    140}
    141
    142static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
    143{
    144	return rb->rg_device;
    145}
    146
    147static inline void *rdmab_data(const struct rpcrdma_regbuf *rb)
    148{
    149	return rb->rg_data;
    150}
    151
    152#define RPCRDMA_DEF_GFP		(GFP_NOIO | __GFP_NOWARN)
    153
    154/* To ensure a transport can always make forward progress,
    155 * the number of RDMA segments allowed in header chunk lists
    156 * is capped at 16. This prevents less-capable devices from
    157 * overrunning the Send buffer while building chunk lists.
    158 *
    159 * Elements of the Read list take up more room than the
    160 * Write list or Reply chunk. 16 read segments means the
    161 * chunk lists cannot consume more than
    162 *
    163 * ((16 + 2) * read segment size) + 1 XDR words,
    164 *
    165 * or about 400 bytes. The fixed part of the header is
    166 * another 24 bytes. Thus when the inline threshold is
    167 * 1024 bytes, at least 600 bytes are available for RPC
    168 * message bodies.
    169 */
    170enum {
    171	RPCRDMA_MAX_HDR_SEGS = 16,
    172};
    173
    174/*
    175 * struct rpcrdma_rep -- this structure encapsulates state required
    176 * to receive and complete an RPC Reply, asychronously. It needs
    177 * several pieces of state:
    178 *
    179 *   o receive buffer and ib_sge (donated to provider)
    180 *   o status of receive (success or not, length, inv rkey)
    181 *   o bookkeeping state to get run by reply handler (XDR stream)
    182 *
    183 * These structures are allocated during transport initialization.
    184 * N of these are associated with a transport instance, managed by
    185 * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
    186 */
    187
    188struct rpcrdma_rep {
    189	struct ib_cqe		rr_cqe;
    190	struct rpc_rdma_cid	rr_cid;
    191
    192	__be32			rr_xid;
    193	__be32			rr_vers;
    194	__be32			rr_proc;
    195	int			rr_wc_flags;
    196	u32			rr_inv_rkey;
    197	bool			rr_temp;
    198	struct rpcrdma_regbuf	*rr_rdmabuf;
    199	struct rpcrdma_xprt	*rr_rxprt;
    200	struct rpc_rqst		*rr_rqst;
    201	struct xdr_buf		rr_hdrbuf;
    202	struct xdr_stream	rr_stream;
    203	struct llist_node	rr_node;
    204	struct ib_recv_wr	rr_recv_wr;
    205	struct list_head	rr_all;
    206};
    207
    208/* To reduce the rate at which a transport invokes ib_post_recv
    209 * (and thus the hardware doorbell rate), xprtrdma posts Receive
    210 * WRs in batches.
    211 *
    212 * Setting this to zero disables Receive post batching.
    213 */
    214enum {
    215	RPCRDMA_MAX_RECV_BATCH = 7,
    216};
    217
    218/* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
    219 */
    220struct rpcrdma_req;
    221struct rpcrdma_sendctx {
    222	struct ib_cqe		sc_cqe;
    223	struct rpc_rdma_cid	sc_cid;
    224	struct rpcrdma_req	*sc_req;
    225	unsigned int		sc_unmap_count;
    226	struct ib_sge		sc_sges[];
    227};
    228
    229/*
    230 * struct rpcrdma_mr - external memory region metadata
    231 *
    232 * An external memory region is any buffer or page that is registered
    233 * on the fly (ie, not pre-registered).
    234 */
    235struct rpcrdma_req;
    236struct rpcrdma_mr {
    237	struct list_head	mr_list;
    238	struct rpcrdma_req	*mr_req;
    239
    240	struct ib_mr		*mr_ibmr;
    241	struct ib_device	*mr_device;
    242	struct scatterlist	*mr_sg;
    243	int			mr_nents;
    244	enum dma_data_direction	mr_dir;
    245	struct ib_cqe		mr_cqe;
    246	struct completion	mr_linv_done;
    247	union {
    248		struct ib_reg_wr	mr_regwr;
    249		struct ib_send_wr	mr_invwr;
    250	};
    251	struct rpcrdma_xprt	*mr_xprt;
    252	u32			mr_handle;
    253	u32			mr_length;
    254	u64			mr_offset;
    255	struct list_head	mr_all;
    256	struct rpc_rdma_cid	mr_cid;
    257};
    258
    259/*
    260 * struct rpcrdma_req -- structure central to the request/reply sequence.
    261 *
    262 * N of these are associated with a transport instance, and stored in
    263 * struct rpcrdma_buffer. N is the max number of outstanding requests.
    264 *
    265 * It includes pre-registered buffer memory for send AND recv.
    266 * The recv buffer, however, is not owned by this structure, and
    267 * is "donated" to the hardware when a recv is posted. When a
    268 * reply is handled, the recv buffer used is given back to the
    269 * struct rpcrdma_req associated with the request.
    270 *
    271 * In addition to the basic memory, this structure includes an array
    272 * of iovs for send operations. The reason is that the iovs passed to
    273 * ib_post_{send,recv} must not be modified until the work request
    274 * completes.
    275 */
    276
    277/* Maximum number of page-sized "segments" per chunk list to be
    278 * registered or invalidated. Must handle a Reply chunk:
    279 */
    280enum {
    281	RPCRDMA_MAX_IOV_SEGS	= 3,
    282	RPCRDMA_MAX_DATA_SEGS	= ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
    283	RPCRDMA_MAX_SEGS	= RPCRDMA_MAX_DATA_SEGS +
    284				  RPCRDMA_MAX_IOV_SEGS,
    285};
    286
    287/* Arguments for DMA mapping and registration */
    288struct rpcrdma_mr_seg {
    289	u32		mr_len;		/* length of segment */
    290	struct page	*mr_page;	/* underlying struct page */
    291	u64		mr_offset;	/* IN: page offset, OUT: iova */
    292};
    293
    294/* The Send SGE array is provisioned to send a maximum size
    295 * inline request:
    296 * - RPC-over-RDMA header
    297 * - xdr_buf head iovec
    298 * - RPCRDMA_MAX_INLINE bytes, in pages
    299 * - xdr_buf tail iovec
    300 *
    301 * The actual number of array elements consumed by each RPC
    302 * depends on the device's max_sge limit.
    303 */
    304enum {
    305	RPCRDMA_MIN_SEND_SGES = 3,
    306	RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
    307	RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
    308};
    309
    310struct rpcrdma_buffer;
    311struct rpcrdma_req {
    312	struct list_head	rl_list;
    313	struct rpc_rqst		rl_slot;
    314	struct rpcrdma_rep	*rl_reply;
    315	struct xdr_stream	rl_stream;
    316	struct xdr_buf		rl_hdrbuf;
    317	struct ib_send_wr	rl_wr;
    318	struct rpcrdma_sendctx	*rl_sendctx;
    319	struct rpcrdma_regbuf	*rl_rdmabuf;	/* xprt header */
    320	struct rpcrdma_regbuf	*rl_sendbuf;	/* rq_snd_buf */
    321	struct rpcrdma_regbuf	*rl_recvbuf;	/* rq_rcv_buf */
    322
    323	struct list_head	rl_all;
    324	struct kref		rl_kref;
    325
    326	struct list_head	rl_free_mrs;
    327	struct list_head	rl_registered;
    328	struct rpcrdma_mr_seg	rl_segments[RPCRDMA_MAX_SEGS];
    329};
    330
    331static inline struct rpcrdma_req *
    332rpcr_to_rdmar(const struct rpc_rqst *rqst)
    333{
    334	return container_of(rqst, struct rpcrdma_req, rl_slot);
    335}
    336
    337static inline void
    338rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
    339{
    340	list_add(&mr->mr_list, list);
    341}
    342
    343static inline struct rpcrdma_mr *
    344rpcrdma_mr_pop(struct list_head *list)
    345{
    346	struct rpcrdma_mr *mr;
    347
    348	mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list);
    349	if (mr)
    350		list_del_init(&mr->mr_list);
    351	return mr;
    352}
    353
    354/*
    355 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
    356 * inline requests/replies, and client/server credits.
    357 *
    358 * One of these is associated with a transport instance
    359 */
    360struct rpcrdma_buffer {
    361	spinlock_t		rb_lock;
    362	struct list_head	rb_send_bufs;
    363	struct list_head	rb_mrs;
    364
    365	unsigned long		rb_sc_head;
    366	unsigned long		rb_sc_tail;
    367	unsigned long		rb_sc_last;
    368	struct rpcrdma_sendctx	**rb_sc_ctxs;
    369
    370	struct list_head	rb_allreqs;
    371	struct list_head	rb_all_mrs;
    372	struct list_head	rb_all_reps;
    373
    374	struct llist_head	rb_free_reps;
    375
    376	__be32			rb_max_requests;
    377	u32			rb_credits;	/* most recent credit grant */
    378
    379	u32			rb_bc_srv_max_requests;
    380	u32			rb_bc_max_requests;
    381
    382	struct work_struct	rb_refresh_worker;
    383};
    384
    385/*
    386 * Statistics for RPCRDMA
    387 */
    388struct rpcrdma_stats {
    389	/* accessed when sending a call */
    390	unsigned long		read_chunk_count;
    391	unsigned long		write_chunk_count;
    392	unsigned long		reply_chunk_count;
    393	unsigned long long	total_rdma_request;
    394
    395	/* rarely accessed error counters */
    396	unsigned long long	pullup_copy_count;
    397	unsigned long		hardway_register_count;
    398	unsigned long		failed_marshal_count;
    399	unsigned long		bad_reply_count;
    400	unsigned long		mrs_recycled;
    401	unsigned long		mrs_orphaned;
    402	unsigned long		mrs_allocated;
    403	unsigned long		empty_sendctx_q;
    404
    405	/* accessed when receiving a reply */
    406	unsigned long long	total_rdma_reply;
    407	unsigned long long	fixup_copy_count;
    408	unsigned long		reply_waits_for_send;
    409	unsigned long		local_inv_needed;
    410	unsigned long		nomsg_call_count;
    411	unsigned long		bcall_count;
    412};
    413
    414/*
    415 * RPCRDMA transport -- encapsulates the structures above for
    416 * integration with RPC.
    417 *
    418 * The contained structures are embedded, not pointers,
    419 * for convenience. This structure need not be visible externally.
    420 *
    421 * It is allocated and initialized during mount, and released
    422 * during unmount.
    423 */
    424struct rpcrdma_xprt {
    425	struct rpc_xprt		rx_xprt;
    426	struct rpcrdma_ep	*rx_ep;
    427	struct rpcrdma_buffer	rx_buf;
    428	struct delayed_work	rx_connect_worker;
    429	struct rpc_timeout	rx_timeout;
    430	struct rpcrdma_stats	rx_stats;
    431};
    432
    433#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
    434
    435static inline const char *
    436rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
    437{
    438	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
    439}
    440
    441static inline const char *
    442rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
    443{
    444	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
    445}
    446
    447/* Setting this to 0 ensures interoperability with early servers.
    448 * Setting this to 1 enhances certain unaligned read/write performance.
    449 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
    450extern int xprt_rdma_pad_optimize;
    451
    452/* This setting controls the hunt for a supported memory
    453 * registration strategy.
    454 */
    455extern unsigned int xprt_rdma_memreg_strategy;
    456
    457/*
    458 * Endpoint calls - xprtrdma/verbs.c
    459 */
    460void rpcrdma_force_disconnect(struct rpcrdma_ep *ep);
    461void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc);
    462int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt);
    463void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt);
    464
    465void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp);
    466
    467/*
    468 * Buffer calls - xprtrdma/verbs.c
    469 */
    470struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
    471				       gfp_t flags);
    472int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
    473void rpcrdma_req_destroy(struct rpcrdma_req *req);
    474int rpcrdma_buffer_create(struct rpcrdma_xprt *);
    475void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
    476struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
    477
    478struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
    479void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
    480
    481struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
    482void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
    483			struct rpcrdma_req *req);
    484void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep);
    485void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req);
    486
    487bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
    488			    gfp_t flags);
    489bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
    490			      struct rpcrdma_regbuf *rb);
    491
    492/**
    493 * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped
    494 *
    495 * Returns true if the buffer is now mapped to rb->rg_device.
    496 */
    497static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
    498{
    499	return rb->rg_device != NULL;
    500}
    501
    502/**
    503 * rpcrdma_regbuf_dma_map - DMA-map a regbuf
    504 * @r_xprt: controlling transport instance
    505 * @rb: regbuf to be mapped
    506 *
    507 * Returns true if the buffer is currently DMA mapped.
    508 */
    509static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
    510					  struct rpcrdma_regbuf *rb)
    511{
    512	if (likely(rpcrdma_regbuf_is_mapped(rb)))
    513		return true;
    514	return __rpcrdma_regbuf_dma_map(r_xprt, rb);
    515}
    516
    517/*
    518 * Wrappers for chunk registration, shared by read/write chunk code.
    519 */
    520
    521static inline enum dma_data_direction
    522rpcrdma_data_dir(bool writing)
    523{
    524	return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
    525}
    526
    527/* Memory registration calls xprtrdma/frwr_ops.c
    528 */
    529void frwr_reset(struct rpcrdma_req *req);
    530int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device);
    531int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr);
    532void frwr_mr_release(struct rpcrdma_mr *mr);
    533struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
    534				struct rpcrdma_mr_seg *seg,
    535				int nsegs, bool writing, __be32 xid,
    536				struct rpcrdma_mr *mr);
    537int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
    538void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
    539void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
    540void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
    541int frwr_wp_create(struct rpcrdma_xprt *r_xprt);
    542
    543/*
    544 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
    545 */
    546
    547enum rpcrdma_chunktype {
    548	rpcrdma_noch = 0,
    549	rpcrdma_noch_pullup,
    550	rpcrdma_noch_mapped,
    551	rpcrdma_readch,
    552	rpcrdma_areadch,
    553	rpcrdma_writech,
    554	rpcrdma_replych
    555};
    556
    557int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
    558			      struct rpcrdma_req *req, u32 hdrlen,
    559			      struct xdr_buf *xdr,
    560			      enum rpcrdma_chunktype rtype);
    561void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
    562int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
    563void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep);
    564void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
    565void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
    566void rpcrdma_unpin_rqst(struct rpcrdma_rep *rep);
    567void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
    568
    569static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
    570{
    571	xdr->head[0].iov_len = len;
    572	xdr->len = len;
    573}
    574
    575/* RPC/RDMA module init - xprtrdma/transport.c
    576 */
    577extern unsigned int xprt_rdma_max_inline_read;
    578extern unsigned int xprt_rdma_max_inline_write;
    579void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
    580void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
    581void xprt_rdma_close(struct rpc_xprt *xprt);
    582void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
    583int xprt_rdma_init(void);
    584void xprt_rdma_cleanup(void);
    585
    586/* Backchannel calls - xprtrdma/backchannel.c
    587 */
    588#if defined(CONFIG_SUNRPC_BACKCHANNEL)
    589int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
    590size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
    591unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
    592int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
    593void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
    594int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
    595void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
    596void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
    597#endif	/* CONFIG_SUNRPC_BACKCHANNEL */
    598
    599extern struct xprt_class xprt_rdma_bc;
    600
    601#endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */