xref: /linux/net/sunrpc/xprtrdma/xprt_rdma.h (revision f879306834818ebd1722a4372079610cdd466fec)
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  */
72 struct rpcrdma_mr;
73 struct 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 
122 struct 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 
129 static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
130 {
131 	return rb->rg_iov.addr;
132 }
133 
134 static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
135 {
136 	return rb->rg_iov.length;
137 }
138 
139 static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
140 {
141 	return rb->rg_iov.lkey;
142 }
143 
144 static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
145 {
146 	return rb->rg_device;
147 }
148 
149 static 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  */
176 enum {
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 
194 struct 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  */
219 enum {
220 	RPCRDMA_MAX_RECV_BATCH = 7,
221 };
222 
223 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
224  */
225 struct rpcrdma_req;
226 struct 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  */
240 struct rpcrdma_req;
241 struct 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  */
285 enum {
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 */
293 struct 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  */
309 enum {
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 
315 struct rpcrdma_buffer;
316 struct 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 
336 static inline struct rpcrdma_req *
337 rpcr_to_rdmar(const struct rpc_rqst *rqst)
338 {
339 	return container_of(rqst, struct rpcrdma_req, rl_slot);
340 }
341 
342 static inline void
343 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
344 {
345 	list_add(&mr->mr_list, list);
346 }
347 
348 static inline struct rpcrdma_mr *
349 rpcrdma_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  */
365 struct 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  */
393 struct 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  */
429 struct 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 
440 static inline const char *
441 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
442 {
443 	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
444 }
445 
446 static inline const char *
447 rpcrdma_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() */
455 extern int xprt_rdma_pad_optimize;
456 
457 /* This setting controls the hunt for a supported memory
458  * registration strategy.
459  */
460 extern unsigned int xprt_rdma_memreg_strategy;
461 
462 /*
463  * Endpoint calls - xprtrdma/verbs.c
464  */
465 void rpcrdma_force_disconnect(struct rpcrdma_ep *ep);
466 void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc);
467 int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt);
468 void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt);
469 
470 void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed);
471 
472 /*
473  * Buffer calls - xprtrdma/verbs.c
474  */
475 struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt,
476 				       size_t size);
477 int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
478 void rpcrdma_req_destroy(struct rpcrdma_req *req);
479 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
480 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
481 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
482 
483 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
484 void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
485 
486 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
487 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
488 			struct rpcrdma_req *req);
489 void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep);
490 void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req);
491 
492 bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
493 			    gfp_t flags);
494 bool __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  */
502 static 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  */
514 static 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 
526 static inline enum dma_data_direction
527 rpcrdma_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  */
534 void frwr_reset(struct rpcrdma_req *req);
535 int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device);
536 int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr);
537 void frwr_mr_release(struct rpcrdma_mr *mr);
538 struct 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);
542 int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
543 void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
544 void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
545 void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
546 int frwr_wp_create(struct rpcrdma_xprt *r_xprt);
547 
548 /*
549  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
550  */
551 
552 enum 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 
562 int 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);
566 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
567 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
568 void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep);
569 void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
570 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
571 void rpcrdma_unpin_rqst(struct rpcrdma_rep *rep);
572 void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
573 
574 static 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  */
582 extern unsigned int xprt_rdma_max_inline_read;
583 extern unsigned int xprt_rdma_max_inline_write;
584 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
585 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
586 void xprt_rdma_close(struct rpc_xprt *xprt);
587 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
588 int xprt_rdma_init(void);
589 void xprt_rdma_cleanup(void);
590 
591 /* Backchannel calls - xprtrdma/backchannel.c
592  */
593 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
594 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
595 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
596 unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
597 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
598 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
599 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
600 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
601 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
602 
603 extern struct xprt_class xprt_rdma_bc;
604 
605 #endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */
606