xref: /openbmc/linux/net/sunrpc/xprtrdma/xprt_rdma.h (revision 0edbfea5)
1 /*
2  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the BSD-type
8  * license below:
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  *
14  *      Redistributions of source code must retain the above copyright
15  *      notice, this list of conditions and the following disclaimer.
16  *
17  *      Redistributions in binary form must reproduce the above
18  *      copyright notice, this list of conditions and the following
19  *      disclaimer in the documentation and/or other materials provided
20  *      with the distribution.
21  *
22  *      Neither the name of the Network Appliance, Inc. nor the names of
23  *      its contributors may be used to endorse or promote products
24  *      derived from this software without specific prior written
25  *      permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 #ifndef _LINUX_SUNRPC_XPRT_RDMA_H
41 #define _LINUX_SUNRPC_XPRT_RDMA_H
42 
43 #include <linux/wait.h> 		/* wait_queue_head_t, etc */
44 #include <linux/spinlock.h> 		/* spinlock_t, etc */
45 #include <linux/atomic.h>			/* atomic_t, etc */
46 #include <linux/workqueue.h>		/* struct work_struct */
47 
48 #include <rdma/rdma_cm.h>		/* RDMA connection api */
49 #include <rdma/ib_verbs.h>		/* RDMA verbs api */
50 
51 #include <linux/sunrpc/clnt.h> 		/* rpc_xprt */
52 #include <linux/sunrpc/rpc_rdma.h> 	/* RPC/RDMA protocol */
53 #include <linux/sunrpc/xprtrdma.h> 	/* xprt parameters */
54 
55 #define RDMA_RESOLVE_TIMEOUT	(5000)	/* 5 seconds */
56 #define RDMA_CONNECT_RETRY_MAX	(2)	/* retries if no listener backlog */
57 
58 #define RPCRDMA_BIND_TO		(60U * HZ)
59 #define RPCRDMA_INIT_REEST_TO	(5U * HZ)
60 #define RPCRDMA_MAX_REEST_TO	(30U * HZ)
61 #define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
62 
63 /*
64  * Interface Adapter -- one per transport instance
65  */
66 struct rpcrdma_ia {
67 	const struct rpcrdma_memreg_ops	*ri_ops;
68 	struct ib_device	*ri_device;
69 	struct rdma_cm_id 	*ri_id;
70 	struct ib_pd		*ri_pd;
71 	struct ib_mr		*ri_dma_mr;
72 	struct completion	ri_done;
73 	int			ri_async_rc;
74 	unsigned int		ri_max_frmr_depth;
75 	unsigned int		ri_max_inline_write;
76 	unsigned int		ri_max_inline_read;
77 	struct ib_qp_attr	ri_qp_attr;
78 	struct ib_qp_init_attr	ri_qp_init_attr;
79 };
80 
81 /*
82  * RDMA Endpoint -- one per transport instance
83  */
84 
85 struct rpcrdma_ep {
86 	atomic_t		rep_cqcount;
87 	int			rep_cqinit;
88 	int			rep_connected;
89 	struct ib_qp_init_attr	rep_attr;
90 	wait_queue_head_t 	rep_connect_wait;
91 	struct rdma_conn_param	rep_remote_cma;
92 	struct sockaddr_storage	rep_remote_addr;
93 	struct delayed_work	rep_connect_worker;
94 };
95 
96 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit)
97 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount)
98 
99 /* Pre-allocate extra Work Requests for handling backward receives
100  * and sends. This is a fixed value because the Work Queues are
101  * allocated when the forward channel is set up.
102  */
103 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
104 #define RPCRDMA_BACKWARD_WRS		(8)
105 #else
106 #define RPCRDMA_BACKWARD_WRS		(0)
107 #endif
108 
109 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
110  *
111  * The below structure appears at the front of a large region of kmalloc'd
112  * memory, which always starts on a good alignment boundary.
113  */
114 
115 struct rpcrdma_regbuf {
116 	size_t			rg_size;
117 	struct rpcrdma_req	*rg_owner;
118 	struct ib_sge		rg_iov;
119 	__be32			rg_base[0] __attribute__ ((aligned(256)));
120 };
121 
122 static inline u64
123 rdmab_addr(struct rpcrdma_regbuf *rb)
124 {
125 	return rb->rg_iov.addr;
126 }
127 
128 static inline u32
129 rdmab_length(struct rpcrdma_regbuf *rb)
130 {
131 	return rb->rg_iov.length;
132 }
133 
134 static inline u32
135 rdmab_lkey(struct rpcrdma_regbuf *rb)
136 {
137 	return rb->rg_iov.lkey;
138 }
139 
140 static inline struct rpcrdma_msg *
141 rdmab_to_msg(struct rpcrdma_regbuf *rb)
142 {
143 	return (struct rpcrdma_msg *)rb->rg_base;
144 }
145 
146 #define RPCRDMA_DEF_GFP		(GFP_NOIO | __GFP_NOWARN)
147 
148 /* To ensure a transport can always make forward progress,
149  * the number of RDMA segments allowed in header chunk lists
150  * is capped at 8. This prevents less-capable devices and
151  * memory registrations from overrunning the Send buffer
152  * while building chunk lists.
153  *
154  * Elements of the Read list take up more room than the
155  * Write list or Reply chunk. 8 read segments means the Read
156  * list (or Write list or Reply chunk) cannot consume more
157  * than
158  *
159  * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
160  *
161  * And the fixed part of the header is another 24 bytes.
162  *
163  * The smallest inline threshold is 1024 bytes, ensuring that
164  * at least 750 bytes are available for RPC messages.
165  */
166 #define RPCRDMA_MAX_HDR_SEGS	(8)
167 
168 /*
169  * struct rpcrdma_rep -- this structure encapsulates state required to recv
170  * and complete a reply, asychronously. It needs several pieces of
171  * state:
172  *   o recv buffer (posted to provider)
173  *   o ib_sge (also donated to provider)
174  *   o status of reply (length, success or not)
175  *   o bookkeeping state to get run by tasklet (list, etc)
176  *
177  * These are allocated during initialization, per-transport instance;
178  * however, the tasklet execution list itself is global, as it should
179  * always be pretty short.
180  *
181  * N of these are associated with a transport instance, and stored in
182  * struct rpcrdma_buffer. N is the max number of outstanding requests.
183  */
184 
185 #define RPCRDMA_MAX_DATA_SEGS	((1 * 1024 * 1024) / PAGE_SIZE)
186 
187 /* data segments + head/tail for Call + head/tail for Reply */
188 #define RPCRDMA_MAX_SEGS 	(RPCRDMA_MAX_DATA_SEGS + 4)
189 
190 struct rpcrdma_buffer;
191 
192 struct rpcrdma_rep {
193 	struct ib_cqe		rr_cqe;
194 	unsigned int		rr_len;
195 	struct ib_device	*rr_device;
196 	struct rpcrdma_xprt	*rr_rxprt;
197 	struct work_struct	rr_work;
198 	struct list_head	rr_list;
199 	struct rpcrdma_regbuf	*rr_rdmabuf;
200 };
201 
202 #define RPCRDMA_BAD_LEN		(~0U)
203 
204 /*
205  * struct rpcrdma_mw - external memory region metadata
206  *
207  * An external memory region is any buffer or page that is registered
208  * on the fly (ie, not pre-registered).
209  *
210  * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During
211  * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
212  * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
213  * track of registration metadata while each RPC is pending.
214  * rpcrdma_deregister_external() uses this metadata to unmap and
215  * release these resources when an RPC is complete.
216  */
217 enum rpcrdma_frmr_state {
218 	FRMR_IS_INVALID,	/* ready to be used */
219 	FRMR_IS_VALID,		/* in use */
220 	FRMR_IS_STALE,		/* failed completion */
221 };
222 
223 struct rpcrdma_frmr {
224 	struct scatterlist		*fr_sg;
225 	int				fr_nents;
226 	enum dma_data_direction		fr_dir;
227 	struct ib_mr			*fr_mr;
228 	struct ib_cqe			fr_cqe;
229 	enum rpcrdma_frmr_state		fr_state;
230 	struct completion		fr_linv_done;
231 	union {
232 		struct ib_reg_wr	fr_regwr;
233 		struct ib_send_wr	fr_invwr;
234 	};
235 };
236 
237 struct rpcrdma_fmr {
238 	struct ib_fmr		*fmr;
239 	u64			*physaddrs;
240 };
241 
242 struct rpcrdma_mw {
243 	union {
244 		struct rpcrdma_fmr	fmr;
245 		struct rpcrdma_frmr	frmr;
246 	};
247 	struct work_struct	mw_work;
248 	struct rpcrdma_xprt	*mw_xprt;
249 	struct list_head	mw_list;
250 	struct list_head	mw_all;
251 };
252 
253 /*
254  * struct rpcrdma_req -- structure central to the request/reply sequence.
255  *
256  * N of these are associated with a transport instance, and stored in
257  * struct rpcrdma_buffer. N is the max number of outstanding requests.
258  *
259  * It includes pre-registered buffer memory for send AND recv.
260  * The recv buffer, however, is not owned by this structure, and
261  * is "donated" to the hardware when a recv is posted. When a
262  * reply is handled, the recv buffer used is given back to the
263  * struct rpcrdma_req associated with the request.
264  *
265  * In addition to the basic memory, this structure includes an array
266  * of iovs for send operations. The reason is that the iovs passed to
267  * ib_post_{send,recv} must not be modified until the work request
268  * completes.
269  *
270  * NOTES:
271  *   o RPCRDMA_MAX_SEGS is the max number of addressible chunk elements we
272  *     marshal. The number needed varies depending on the iov lists that
273  *     are passed to us, the memory registration mode we are in, and if
274  *     physical addressing is used, the layout.
275  */
276 
277 struct rpcrdma_mr_seg {		/* chunk descriptors */
278 	struct rpcrdma_mw *rl_mw;	/* registered MR */
279 	u64		mr_base;	/* registration result */
280 	u32		mr_rkey;	/* registration result */
281 	u32		mr_len;		/* length of chunk or segment */
282 	int		mr_nsegs;	/* number of segments in chunk or 0 */
283 	enum dma_data_direction	mr_dir;	/* segment mapping direction */
284 	dma_addr_t	mr_dma;		/* segment mapping address */
285 	size_t		mr_dmalen;	/* segment mapping length */
286 	struct page	*mr_page;	/* owning page, if any */
287 	char		*mr_offset;	/* kva if no page, else offset */
288 };
289 
290 #define RPCRDMA_MAX_IOVS	(2)
291 
292 struct rpcrdma_req {
293 	struct list_head	rl_free;
294 	unsigned int		rl_niovs;
295 	unsigned int		rl_nchunks;
296 	unsigned int		rl_connect_cookie;
297 	struct rpc_task		*rl_task;
298 	struct rpcrdma_buffer	*rl_buffer;
299 	struct rpcrdma_rep	*rl_reply;/* holder for reply buffer */
300 	struct ib_sge		rl_send_iov[RPCRDMA_MAX_IOVS];
301 	struct rpcrdma_regbuf	*rl_rdmabuf;
302 	struct rpcrdma_regbuf	*rl_sendbuf;
303 	struct rpcrdma_mr_seg	rl_segments[RPCRDMA_MAX_SEGS];
304 	struct rpcrdma_mr_seg	*rl_nextseg;
305 
306 	struct ib_cqe		rl_cqe;
307 	struct list_head	rl_all;
308 	bool			rl_backchannel;
309 };
310 
311 static inline struct rpcrdma_req *
312 rpcr_to_rdmar(struct rpc_rqst *rqst)
313 {
314 	void *buffer = rqst->rq_buffer;
315 	struct rpcrdma_regbuf *rb;
316 
317 	rb = container_of(buffer, struct rpcrdma_regbuf, rg_base);
318 	return rb->rg_owner;
319 }
320 
321 /*
322  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
323  * inline requests/replies, and client/server credits.
324  *
325  * One of these is associated with a transport instance
326  */
327 struct rpcrdma_buffer {
328 	spinlock_t		rb_mwlock;	/* protect rb_mws list */
329 	struct list_head	rb_mws;
330 	struct list_head	rb_all;
331 	char			*rb_pool;
332 
333 	spinlock_t		rb_lock;	/* protect buf lists */
334 	struct list_head	rb_send_bufs;
335 	struct list_head	rb_recv_bufs;
336 	u32			rb_max_requests;
337 	atomic_t		rb_credits;	/* most recent credit grant */
338 
339 	u32			rb_bc_srv_max_requests;
340 	spinlock_t		rb_reqslock;	/* protect rb_allreqs */
341 	struct list_head	rb_allreqs;
342 
343 	u32			rb_bc_max_requests;
344 };
345 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
346 
347 /*
348  * Internal structure for transport instance creation. This
349  * exists primarily for modularity.
350  *
351  * This data should be set with mount options
352  */
353 struct rpcrdma_create_data_internal {
354 	struct sockaddr_storage	addr;	/* RDMA server address */
355 	unsigned int	max_requests;	/* max requests (slots) in flight */
356 	unsigned int	rsize;		/* mount rsize - max read hdr+data */
357 	unsigned int	wsize;		/* mount wsize - max write hdr+data */
358 	unsigned int	inline_rsize;	/* max non-rdma read data payload */
359 	unsigned int	inline_wsize;	/* max non-rdma write data payload */
360 	unsigned int	padding;	/* non-rdma write header padding */
361 };
362 
363 #define RPCRDMA_INLINE_READ_THRESHOLD(rq) \
364 	(rpcx_to_rdmad(rq->rq_xprt).inline_rsize)
365 
366 #define RPCRDMA_INLINE_WRITE_THRESHOLD(rq)\
367 	(rpcx_to_rdmad(rq->rq_xprt).inline_wsize)
368 
369 #define RPCRDMA_INLINE_PAD_VALUE(rq)\
370 	rpcx_to_rdmad(rq->rq_xprt).padding
371 
372 /*
373  * Statistics for RPCRDMA
374  */
375 struct rpcrdma_stats {
376 	unsigned long		read_chunk_count;
377 	unsigned long		write_chunk_count;
378 	unsigned long		reply_chunk_count;
379 
380 	unsigned long long	total_rdma_request;
381 	unsigned long long	total_rdma_reply;
382 
383 	unsigned long long	pullup_copy_count;
384 	unsigned long long	fixup_copy_count;
385 	unsigned long		hardway_register_count;
386 	unsigned long		failed_marshal_count;
387 	unsigned long		bad_reply_count;
388 	unsigned long		nomsg_call_count;
389 	unsigned long		bcall_count;
390 };
391 
392 /*
393  * Per-registration mode operations
394  */
395 struct rpcrdma_xprt;
396 struct rpcrdma_memreg_ops {
397 	int		(*ro_map)(struct rpcrdma_xprt *,
398 				  struct rpcrdma_mr_seg *, int, bool);
399 	void		(*ro_unmap_sync)(struct rpcrdma_xprt *,
400 					 struct rpcrdma_req *);
401 	void		(*ro_unmap_safe)(struct rpcrdma_xprt *,
402 					 struct rpcrdma_req *, bool);
403 	int		(*ro_open)(struct rpcrdma_ia *,
404 				   struct rpcrdma_ep *,
405 				   struct rpcrdma_create_data_internal *);
406 	size_t		(*ro_maxpages)(struct rpcrdma_xprt *);
407 	int		(*ro_init)(struct rpcrdma_xprt *);
408 	void		(*ro_destroy)(struct rpcrdma_buffer *);
409 	const char	*ro_displayname;
410 };
411 
412 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
413 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
414 extern const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops;
415 
416 /*
417  * RPCRDMA transport -- encapsulates the structures above for
418  * integration with RPC.
419  *
420  * The contained structures are embedded, not pointers,
421  * for convenience. This structure need not be visible externally.
422  *
423  * It is allocated and initialized during mount, and released
424  * during unmount.
425  */
426 struct rpcrdma_xprt {
427 	struct rpc_xprt		rx_xprt;
428 	struct rpcrdma_ia	rx_ia;
429 	struct rpcrdma_ep	rx_ep;
430 	struct rpcrdma_buffer	rx_buf;
431 	struct rpcrdma_create_data_internal rx_data;
432 	struct delayed_work	rx_connect_worker;
433 	struct rpcrdma_stats	rx_stats;
434 };
435 
436 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
437 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
438 
439 /* Setting this to 0 ensures interoperability with early servers.
440  * Setting this to 1 enhances certain unaligned read/write performance.
441  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
442 extern int xprt_rdma_pad_optimize;
443 
444 /*
445  * Interface Adapter calls - xprtrdma/verbs.c
446  */
447 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int);
448 void rpcrdma_ia_close(struct rpcrdma_ia *);
449 
450 /*
451  * Endpoint calls - xprtrdma/verbs.c
452  */
453 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
454 				struct rpcrdma_create_data_internal *);
455 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
456 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
457 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
458 
459 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
460 				struct rpcrdma_req *);
461 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_ep *,
462 				struct rpcrdma_rep *);
463 
464 /*
465  * Buffer calls - xprtrdma/verbs.c
466  */
467 struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *);
468 struct rpcrdma_rep *rpcrdma_create_rep(struct rpcrdma_xprt *);
469 void rpcrdma_destroy_req(struct rpcrdma_ia *, struct rpcrdma_req *);
470 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
471 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
472 
473 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *);
474 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *);
475 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
476 void rpcrdma_buffer_put(struct rpcrdma_req *);
477 void rpcrdma_recv_buffer_get(struct rpcrdma_req *);
478 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
479 
480 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
481 					    size_t, gfp_t);
482 void rpcrdma_free_regbuf(struct rpcrdma_ia *,
483 			 struct rpcrdma_regbuf *);
484 
485 int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);
486 
487 int frwr_alloc_recovery_wq(void);
488 void frwr_destroy_recovery_wq(void);
489 
490 int rpcrdma_alloc_wq(void);
491 void rpcrdma_destroy_wq(void);
492 
493 /*
494  * Wrappers for chunk registration, shared by read/write chunk code.
495  */
496 
497 void rpcrdma_mapping_error(struct rpcrdma_mr_seg *);
498 
499 static inline enum dma_data_direction
500 rpcrdma_data_dir(bool writing)
501 {
502 	return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
503 }
504 
505 static inline void
506 rpcrdma_map_one(struct ib_device *device, struct rpcrdma_mr_seg *seg,
507 		enum dma_data_direction direction)
508 {
509 	seg->mr_dir = direction;
510 	seg->mr_dmalen = seg->mr_len;
511 
512 	if (seg->mr_page)
513 		seg->mr_dma = ib_dma_map_page(device,
514 				seg->mr_page, offset_in_page(seg->mr_offset),
515 				seg->mr_dmalen, seg->mr_dir);
516 	else
517 		seg->mr_dma = ib_dma_map_single(device,
518 				seg->mr_offset,
519 				seg->mr_dmalen, seg->mr_dir);
520 
521 	if (ib_dma_mapping_error(device, seg->mr_dma))
522 		rpcrdma_mapping_error(seg);
523 }
524 
525 static inline void
526 rpcrdma_unmap_one(struct ib_device *device, struct rpcrdma_mr_seg *seg)
527 {
528 	if (seg->mr_page)
529 		ib_dma_unmap_page(device,
530 				  seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
531 	else
532 		ib_dma_unmap_single(device,
533 				    seg->mr_dma, seg->mr_dmalen, seg->mr_dir);
534 }
535 
536 /*
537  * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c
538  */
539 void rpcrdma_connect_worker(struct work_struct *);
540 void rpcrdma_conn_func(struct rpcrdma_ep *);
541 void rpcrdma_reply_handler(struct rpcrdma_rep *);
542 
543 /*
544  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
545  */
546 int rpcrdma_marshal_req(struct rpc_rqst *);
547 void rpcrdma_set_max_header_sizes(struct rpcrdma_ia *,
548 				  struct rpcrdma_create_data_internal *,
549 				  unsigned int);
550 
551 /* RPC/RDMA module init - xprtrdma/transport.c
552  */
553 extern unsigned int xprt_rdma_max_inline_read;
554 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
555 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
556 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
557 int xprt_rdma_init(void);
558 void xprt_rdma_cleanup(void);
559 
560 /* Backchannel calls - xprtrdma/backchannel.c
561  */
562 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
563 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
564 int xprt_rdma_bc_up(struct svc_serv *, struct net *);
565 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
566 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
567 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
568 int rpcrdma_bc_marshal_reply(struct rpc_rqst *);
569 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
570 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
571 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
572 
573 extern struct xprt_class xprt_rdma_bc;
574 
575 #endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */
576