summaryrefslogtreecommitdiffstats
path: root/net/sunrpc/xprtrdma/xprt_rdma.h
blob: 8a3ac9d7ee8148051ac529487d239b81d20150c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
/* 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.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)

/*
 * Interface Adapter -- one per transport instance
 */
struct rpcrdma_ia {
	struct rdma_cm_id 	*ri_id;
	struct ib_pd		*ri_pd;
	int			ri_async_rc;
	unsigned int		ri_max_rdma_segs;
	unsigned int		ri_max_frwr_depth;
	bool			ri_implicit_roundup;
	enum ib_mr_type		ri_mrtype;
	struct completion	ri_done;
	struct completion	ri_remove_done;
};

/*
 * RDMA Endpoint -- one per transport instance
 */

struct rpcrdma_ep {
	unsigned int		rep_send_count;
	unsigned int		rep_send_batch;
	unsigned int		rep_max_inline_send;
	unsigned int		rep_max_inline_recv;
	int			rep_connected;
	struct ib_qp_init_attr	rep_attr;
	wait_queue_head_t 	rep_connect_wait;
	struct rpcrdma_connect_private	rep_cm_private;
	struct rdma_conn_param	rep_remote_cma;
	unsigned int		rep_max_requests;	/* depends on device */
	unsigned int		rep_inline_send;	/* negotiated */
	unsigned int		rep_inline_recv;	/* negotiated */
	int			rep_receive_count;
};

/* Pre-allocate extra Work Requests for handling backward 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;
}

#define RPCRDMA_DEF_GFP		(GFP_NOIO | __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;
	__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 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_frwr {
	struct ib_mr			*fr_mr;
	struct ib_cqe			fr_cqe;
	struct completion		fr_linv_done;
	union {
		struct ib_reg_wr	fr_regwr;
		struct ib_send_wr	fr_invwr;
	};
};

struct rpcrdma_req;
struct rpcrdma_mr {
	struct list_head	mr_list;
	struct rpcrdma_req	*mr_req;
	struct scatterlist	*mr_sg;
	int			mr_nents;
	enum dma_data_direction	mr_dir;
	struct rpcrdma_frwr	frwr;
	struct rpcrdma_xprt	*mr_xprt;
	u32			mr_handle;
	u32			mr_length;
	u64			mr_offset;
	struct list_head	mr_all;
};

/*
 * 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,
};

struct rpcrdma_mr_seg {		/* chunk descriptors */
	u32		mr_len;		/* length of chunk or segment */
	struct page	*mr_page;	/* owning page, if any */
	char		*mr_offset;	/* kva if no page, else offset */
};

/* 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_ia	rx_ia;
	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_flush_disconnect(struct ib_cq *cq, struct ib_wc *wc);
int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt);
void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt);

int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);

/*
 * Buffer calls - xprtrdma/verbs.c
 */
struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
				       gfp_t flags);
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_mr_put(struct rpcrdma_mr *mr);
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_recv_buffer_put(struct rpcrdma_rep *);

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_xprt *r_xprt,
		      const struct ib_device *device);
int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr);
void frwr_release_mr(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);

/*
 * 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_xprt *);
void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
void rpcrdma_complete_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 *);
int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
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 */