xprt_rdma.h

  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#include <linux/sunrpc/rdma_rn.h>	/* removal notifications */
 60
 61#define RDMA_RESOLVE_TIMEOUT	(5000)	/* 5 seconds */
 62#define RDMA_CONNECT_RETRY_MAX	(2)	/* retries if no listener backlog */
 63
 64#define RPCRDMA_BIND_TO		(60U * HZ)
 65#define RPCRDMA_INIT_REEST_TO	(5U * HZ)
 66#define RPCRDMA_MAX_REEST_TO	(30U * HZ)
 67#define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
 68
 69/*
 70 * RDMA Endpoint -- connection endpoint details
 71 */
 72struct rpcrdma_mr;
 73struct rpcrdma_ep {
 74	struct kref		re_kref;
 75	struct rdma_cm_id 	*re_id;
 76	struct ib_pd		*re_pd;
 77	unsigned int		re_max_rdma_segs;
 78	unsigned int		re_max_fr_depth;
 79	struct rpcrdma_mr	*re_write_pad_mr;
 80	enum ib_mr_type		re_mrtype;
 81	struct completion	re_done;
 82	unsigned int		re_send_count;
 83	unsigned int		re_send_batch;
 84	unsigned int		re_max_inline_send;
 85	unsigned int		re_max_inline_recv;
 86	int			re_async_rc;
 87	int			re_connect_status;
 88	atomic_t		re_receiving;
 89	atomic_t		re_force_disconnect;
 90	struct ib_qp_init_attr	re_attr;
 91	wait_queue_head_t       re_connect_wait;
 92	struct rpc_xprt		*re_xprt;
 93	struct rpcrdma_connect_private
 94				re_cm_private;
 95	struct rdma_conn_param	re_remote_cma;
 96	struct rpcrdma_notification	re_rn;
 97	int			re_receive_count;
 98	unsigned int		re_max_requests; /* depends on device */
 99	unsigned int		re_inline_send;	/* negotiated */
100	unsigned int		re_inline_recv;	/* negotiated */
101
102	atomic_t		re_completion_ids;
103
104	char			re_write_pad[XDR_UNIT];
105};
106
107/* Pre-allocate extra Work Requests for handling reverse-direction
108 * Receives and Sends. This is a fixed value because the Work Queues
109 * are allocated when the forward channel is set up, long before the
110 * backchannel is provisioned. This value is two times
111 * NFS4_DEF_CB_SLOT_TABLE_SIZE.
112 */
113#if defined(CONFIG_SUNRPC_BACKCHANNEL)
114#define RPCRDMA_BACKWARD_WRS (32)
115#else
116#define RPCRDMA_BACKWARD_WRS (0)
117#endif
118
119/* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
120 */
121
122struct rpcrdma_regbuf {
123	struct ib_sge		rg_iov;
124	struct ib_device	*rg_device;
125	enum dma_data_direction	rg_direction;
126	void			*rg_data;
127};
128
129static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
130{
131	return rb->rg_iov.addr;
132}
133
134static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
135{
136	return rb->rg_iov.length;
137}
138
139static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
140{
141	return rb->rg_iov.lkey;
142}
143
144static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
145{
146	return rb->rg_device;
147}
148
149static inline void *rdmab_data(const struct rpcrdma_regbuf *rb)
150{
151	return rb->rg_data;
152}
153
154/* Do not use emergency memory reserves, and fail quickly if memory
155 * cannot be allocated easily. These flags may be used wherever there
156 * is robust logic to handle a failure to allocate.
157 */
158#define XPRTRDMA_GFP_FLAGS  (__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN)
159
160/* To ensure a transport can always make forward progress,
161 * the number of RDMA segments allowed in header chunk lists
162 * is capped at 16. This prevents less-capable devices from
163 * overrunning the Send buffer while building chunk lists.
164 *
165 * Elements of the Read list take up more room than the
166 * Write list or Reply chunk. 16 read segments means the
167 * chunk lists cannot consume more than
168 *
169 * ((16 + 2) * read segment size) + 1 XDR words,
170 *
171 * or about 400 bytes. The fixed part of the header is
172 * another 24 bytes. Thus when the inline threshold is
173 * 1024 bytes, at least 600 bytes are available for RPC
174 * message bodies.
175 */
176enum {
177	RPCRDMA_MAX_HDR_SEGS = 16,
178};
179
180/*
181 * struct rpcrdma_rep -- this structure encapsulates state required
182 * to receive and complete an RPC Reply, asychronously. It needs
183 * several pieces of state:
184 *
185 *   o receive buffer and ib_sge (donated to provider)
186 *   o status of receive (success or not, length, inv rkey)
187 *   o bookkeeping state to get run by reply handler (XDR stream)
188 *
189 * These structures are allocated during transport initialization.
190 * N of these are associated with a transport instance, managed by
191 * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
192 */
193
194struct rpcrdma_rep {
195	struct ib_cqe		rr_cqe;
196	struct rpc_rdma_cid	rr_cid;
197
198	__be32			rr_xid;
199	__be32			rr_vers;
200	__be32			rr_proc;
201	int			rr_wc_flags;
202	u32			rr_inv_rkey;
203	struct rpcrdma_regbuf	*rr_rdmabuf;
204	struct rpcrdma_xprt	*rr_rxprt;
205	struct rpc_rqst		*rr_rqst;
206	struct xdr_buf		rr_hdrbuf;
207	struct xdr_stream	rr_stream;
208	struct llist_node	rr_node;
209	struct ib_recv_wr	rr_recv_wr;
210	struct list_head	rr_all;
211};
212
213/* To reduce the rate at which a transport invokes ib_post_recv
214 * (and thus the hardware doorbell rate), xprtrdma posts Receive
215 * WRs in batches.
216 *
217 * Setting this to zero disables Receive post batching.
218 */
219enum {
220	RPCRDMA_MAX_RECV_BATCH = 7,
221};
222
223/* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
224 */
225struct rpcrdma_req;
226struct rpcrdma_sendctx {
227	struct ib_cqe		sc_cqe;
228	struct rpc_rdma_cid	sc_cid;
229	struct rpcrdma_req	*sc_req;
230	unsigned int		sc_unmap_count;
231	struct ib_sge		sc_sges[];
232};
233
234/*
235 * struct rpcrdma_mr - external memory region metadata
236 *
237 * An external memory region is any buffer or page that is registered
238 * on the fly (ie, not pre-registered).
239 */
240struct rpcrdma_req;
241struct rpcrdma_mr {
242	struct list_head	mr_list;
243	struct rpcrdma_req	*mr_req;
244
245	struct ib_mr		*mr_ibmr;
246	struct ib_device	*mr_device;
247	struct scatterlist	*mr_sg;
248	int			mr_nents;
249	enum dma_data_direction	mr_dir;
250	struct ib_cqe		mr_cqe;
251	struct completion	mr_linv_done;
252	union {
253		struct ib_reg_wr	mr_regwr;
254		struct ib_send_wr	mr_invwr;
255	};
256	struct rpcrdma_xprt	*mr_xprt;
257	u32			mr_handle;
258	u32			mr_length;
259	u64			mr_offset;
260	struct list_head	mr_all;
261	struct rpc_rdma_cid	mr_cid;
262};
263
264/*
265 * struct rpcrdma_req -- structure central to the request/reply sequence.
266 *
267 * N of these are associated with a transport instance, and stored in
268 * struct rpcrdma_buffer. N is the max number of outstanding requests.
269 *
270 * It includes pre-registered buffer memory for send AND recv.
271 * The recv buffer, however, is not owned by this structure, and
272 * is "donated" to the hardware when a recv is posted. When a
273 * reply is handled, the recv buffer used is given back to the
274 * struct rpcrdma_req associated with the request.
275 *
276 * In addition to the basic memory, this structure includes an array
277 * of iovs for send operations. The reason is that the iovs passed to
278 * ib_post_{send,recv} must not be modified until the work request
279 * completes.
280 */
281
282/* Maximum number of page-sized "segments" per chunk list to be
283 * registered or invalidated. Must handle a Reply chunk:
284 */
285enum {
286	RPCRDMA_MAX_IOV_SEGS	= 3,
287	RPCRDMA_MAX_DATA_SEGS	= ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
288	RPCRDMA_MAX_SEGS	= RPCRDMA_MAX_DATA_SEGS +
289				  RPCRDMA_MAX_IOV_SEGS,
290};
291
292/* Arguments for DMA mapping and registration */
293struct rpcrdma_mr_seg {
294	u32		mr_len;		/* length of segment */
295	struct page	*mr_page;	/* underlying struct page */
296	u64		mr_offset;	/* IN: page offset, OUT: iova */
297};
298
299/* The Send SGE array is provisioned to send a maximum size
300 * inline request:
301 * - RPC-over-RDMA header
302 * - xdr_buf head iovec
303 * - RPCRDMA_MAX_INLINE bytes, in pages
304 * - xdr_buf tail iovec
305 *
306 * The actual number of array elements consumed by each RPC
307 * depends on the device's max_sge limit.
308 */
309enum {
310	RPCRDMA_MIN_SEND_SGES = 3,
311	RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
312	RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
313};
314
315struct rpcrdma_buffer;
316struct rpcrdma_req {
317	struct list_head	rl_list;
318	struct rpc_rqst		rl_slot;
319	struct rpcrdma_rep	*rl_reply;
320	struct xdr_stream	rl_stream;
321	struct xdr_buf		rl_hdrbuf;
322	struct ib_send_wr	rl_wr;
323	struct rpcrdma_sendctx	*rl_sendctx;
324	struct rpcrdma_regbuf	*rl_rdmabuf;	/* xprt header */
325	struct rpcrdma_regbuf	*rl_sendbuf;	/* rq_snd_buf */
326	struct rpcrdma_regbuf	*rl_recvbuf;	/* rq_rcv_buf */
327
328	struct list_head	rl_all;
329	struct kref		rl_kref;
330
331	struct list_head	rl_free_mrs;
332	struct list_head	rl_registered;
333	struct rpcrdma_mr_seg	rl_segments[RPCRDMA_MAX_SEGS];
334};
335
336static inline struct rpcrdma_req *
337rpcr_to_rdmar(const struct rpc_rqst *rqst)
338{
339	return container_of(rqst, struct rpcrdma_req, rl_slot);
340}
341
342static inline void
343rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
344{
345	list_add(&mr->mr_list, list);
346}
347
348static inline struct rpcrdma_mr *
349rpcrdma_mr_pop(struct list_head *list)
350{
351	struct rpcrdma_mr *mr;
352
353	mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list);
354	if (mr)
355		list_del_init(&mr->mr_list);
356	return mr;
357}
358
359/*
360 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
361 * inline requests/replies, and client/server credits.
362 *
363 * One of these is associated with a transport instance
364 */
365struct rpcrdma_buffer {
366	spinlock_t		rb_lock;
367	struct list_head	rb_send_bufs;
368	struct list_head	rb_mrs;
369
370	unsigned long		rb_sc_head;
371	unsigned long		rb_sc_tail;
372	unsigned long		rb_sc_last;
373	struct rpcrdma_sendctx	**rb_sc_ctxs;
374
375	struct list_head	rb_allreqs;
376	struct list_head	rb_all_mrs;
377	struct list_head	rb_all_reps;
378
379	struct llist_head	rb_free_reps;
380
381	__be32			rb_max_requests;
382	u32			rb_credits;	/* most recent credit grant */
383
384	u32			rb_bc_srv_max_requests;
385	u32			rb_bc_max_requests;
386
387	struct work_struct	rb_refresh_worker;
388};
389
390/*
391 * Statistics for RPCRDMA
392 */
393struct rpcrdma_stats {
394	/* accessed when sending a call */
395	unsigned long		read_chunk_count;
396	unsigned long		write_chunk_count;
397	unsigned long		reply_chunk_count;
398	unsigned long long	total_rdma_request;
399
400	/* rarely accessed error counters */
401	unsigned long long	pullup_copy_count;
402	unsigned long		hardway_register_count;
403	unsigned long		failed_marshal_count;
404	unsigned long		bad_reply_count;
405	unsigned long		mrs_recycled;
406	unsigned long		mrs_orphaned;
407	unsigned long		mrs_allocated;
408	unsigned long		empty_sendctx_q;
409
410	/* accessed when receiving a reply */
411	unsigned long long	total_rdma_reply;
412	unsigned long long	fixup_copy_count;
413	unsigned long		reply_waits_for_send;
414	unsigned long		local_inv_needed;
415	unsigned long		nomsg_call_count;
416	unsigned long		bcall_count;
417};
418
419/*
420 * RPCRDMA transport -- encapsulates the structures above for
421 * integration with RPC.
422 *
423 * The contained structures are embedded, not pointers,
424 * for convenience. This structure need not be visible externally.
425 *
426 * It is allocated and initialized during mount, and released
427 * during unmount.
428 */
429struct rpcrdma_xprt {
430	struct rpc_xprt		rx_xprt;
431	struct rpcrdma_ep	*rx_ep;
432	struct rpcrdma_buffer	rx_buf;
433	struct delayed_work	rx_connect_worker;
434	struct rpc_timeout	rx_timeout;
435	struct rpcrdma_stats	rx_stats;
436};
437
438#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
439
440static inline const char *
441rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
442{
443	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
444}
445
446static inline const char *
447rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
448{
449	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
450}
451
452/* Setting this to 0 ensures interoperability with early servers.
453 * Setting this to 1 enhances certain unaligned read/write performance.
454 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
455extern int xprt_rdma_pad_optimize;
456
457/* This setting controls the hunt for a supported memory
458 * registration strategy.
459 */
460extern unsigned int xprt_rdma_memreg_strategy;
461
462/*
463 * Endpoint calls - xprtrdma/verbs.c
464 */
465void rpcrdma_force_disconnect(struct rpcrdma_ep *ep);
466void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc);
467int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt);
468void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt);
469
470void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed);
471
472/*
473 * Buffer calls - xprtrdma/verbs.c
474 */
475struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt,
476				       size_t size);
477int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
478void rpcrdma_req_destroy(struct rpcrdma_req *req);
479int rpcrdma_buffer_create(struct rpcrdma_xprt *);
480void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
481struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
482
483struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
484void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
485
486struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
487void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
488			struct rpcrdma_req *req);
489void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep);
490void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req);
491
492bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
493			    gfp_t flags);
494bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
495			      struct rpcrdma_regbuf *rb);
496
497/**
498 * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped
499 *
500 * Returns true if the buffer is now mapped to rb->rg_device.
501 */
502static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
503{
504	return rb->rg_device != NULL;
505}
506
507/**
508 * rpcrdma_regbuf_dma_map - DMA-map a regbuf
509 * @r_xprt: controlling transport instance
510 * @rb: regbuf to be mapped
511 *
512 * Returns true if the buffer is currently DMA mapped.
513 */
514static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
515					  struct rpcrdma_regbuf *rb)
516{
517	if (likely(rpcrdma_regbuf_is_mapped(rb)))
518		return true;
519	return __rpcrdma_regbuf_dma_map(r_xprt, rb);
520}
521
522/*
523 * Wrappers for chunk registration, shared by read/write chunk code.
524 */
525
526static inline enum dma_data_direction
527rpcrdma_data_dir(bool writing)
528{
529	return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
530}
531
532/* Memory registration calls xprtrdma/frwr_ops.c
533 */
534void frwr_reset(struct rpcrdma_req *req);
535int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device);
536int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr);
537void frwr_mr_release(struct rpcrdma_mr *mr);
538struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
539				struct rpcrdma_mr_seg *seg,
540				int nsegs, bool writing, __be32 xid,
541				struct rpcrdma_mr *mr);
542int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
543void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
544void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
545void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
546int frwr_wp_create(struct rpcrdma_xprt *r_xprt);
547
548/*
549 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
550 */
551
552enum rpcrdma_chunktype {
553	rpcrdma_noch = 0,
554	rpcrdma_noch_pullup,
555	rpcrdma_noch_mapped,
556	rpcrdma_readch,
557	rpcrdma_areadch,
558	rpcrdma_writech,
559	rpcrdma_replych
560};
561
562int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
563			      struct rpcrdma_req *req, u32 hdrlen,
564			      struct xdr_buf *xdr,
565			      enum rpcrdma_chunktype rtype);
566void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
567int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
568void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep);
569void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
570void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
571void rpcrdma_unpin_rqst(struct rpcrdma_rep *rep);
572void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
573
574static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
575{
576	xdr->head[0].iov_len = len;
577	xdr->len = len;
578}
579
580/* RPC/RDMA module init - xprtrdma/transport.c
581 */
582extern unsigned int xprt_rdma_max_inline_read;
583extern unsigned int xprt_rdma_max_inline_write;
584void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
585void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
586void xprt_rdma_close(struct rpc_xprt *xprt);
587void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
588int xprt_rdma_init(void);
589void xprt_rdma_cleanup(void);
590
591/* Backchannel calls - xprtrdma/backchannel.c
592 */
593#if defined(CONFIG_SUNRPC_BACKCHANNEL)
594int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
595size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
596unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
597void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
598int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
599void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
600void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
601#endif	/* CONFIG_SUNRPC_BACKCHANNEL */
602
603extern struct xprt_class xprt_rdma_bc;
604
605#endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */