xref: /linux/net/sunrpc/xprtrdma/xprt_rdma.h (revision b85900e91c8402bedc1db14e6d293e26f25d30d4)
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_recv_batch;
100 	unsigned int		re_inline_send;	/* negotiated */
101 	unsigned int		re_inline_recv;	/* negotiated */
102 
103 	atomic_t		re_completion_ids;
104 
105 	char			re_write_pad[XDR_UNIT];
106 };
107 
108 /* Pre-allocate extra Work Requests for handling reverse-direction
109  * Receives and Sends. This is a fixed value because the Work Queues
110  * are allocated when the forward channel is set up, long before the
111  * backchannel is provisioned. This value is two times
112  * NFS4_DEF_CB_SLOT_TABLE_SIZE.
113  */
114 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
115 #define RPCRDMA_BACKWARD_WRS (32)
116 #else
117 #define RPCRDMA_BACKWARD_WRS (0)
118 #endif
119 
120 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
121  */
122 
123 struct rpcrdma_regbuf {
124 	struct ib_sge		rg_iov;
125 	struct ib_device	*rg_device;
126 	enum dma_data_direction	rg_direction;
127 	void			*rg_data;
128 };
129 
rdmab_addr(struct rpcrdma_regbuf * rb)130 static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb)
131 {
132 	return rb->rg_iov.addr;
133 }
134 
rdmab_length(struct rpcrdma_regbuf * rb)135 static inline u32 rdmab_length(struct rpcrdma_regbuf *rb)
136 {
137 	return rb->rg_iov.length;
138 }
139 
rdmab_lkey(struct rpcrdma_regbuf * rb)140 static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb)
141 {
142 	return rb->rg_iov.lkey;
143 }
144 
rdmab_device(struct rpcrdma_regbuf * rb)145 static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb)
146 {
147 	return rb->rg_device;
148 }
149 
rdmab_data(const struct rpcrdma_regbuf * rb)150 static inline void *rdmab_data(const struct rpcrdma_regbuf *rb)
151 {
152 	return rb->rg_data;
153 }
154 
155 /* Do not use emergency memory reserves, and fail quickly if memory
156  * cannot be allocated easily. These flags may be used wherever there
157  * is robust logic to handle a failure to allocate.
158  */
159 #define XPRTRDMA_GFP_FLAGS  (__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN)
160 
161 /* To ensure a transport can always make forward progress,
162  * the number of RDMA segments allowed in header chunk lists
163  * is capped at 16. This prevents less-capable devices from
164  * overrunning the Send buffer while building chunk lists.
165  *
166  * Elements of the Read list take up more room than the
167  * Write list or Reply chunk. 16 read segments means the
168  * chunk lists cannot consume more than
169  *
170  * ((16 + 2) * read segment size) + 1 XDR words,
171  *
172  * or about 400 bytes. The fixed part of the header is
173  * another 24 bytes. Thus when the inline threshold is
174  * 1024 bytes, at least 600 bytes are available for RPC
175  * message bodies.
176  */
177 enum {
178 	RPCRDMA_MAX_HDR_SEGS = 16,
179 };
180 
181 /*
182  * struct rpcrdma_rep -- this structure encapsulates state required
183  * to receive and complete an RPC Reply, asychronously. It needs
184  * several pieces of state:
185  *
186  *   o receive buffer and ib_sge (donated to provider)
187  *   o status of receive (success or not, length, inv rkey)
188  *   o bookkeeping state to get run by reply handler (XDR stream)
189  *
190  * These structures are allocated during transport initialization.
191  * N of these are associated with a transport instance, managed by
192  * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
193  */
194 
195 struct rpcrdma_rep {
196 	struct ib_cqe		rr_cqe;
197 	struct rpc_rdma_cid	rr_cid;
198 
199 	__be32			rr_xid;
200 	__be32			rr_vers;
201 	__be32			rr_proc;
202 	int			rr_wc_flags;
203 	u32			rr_inv_rkey;
204 	struct rpcrdma_regbuf	*rr_rdmabuf;
205 	struct rpcrdma_xprt	*rr_rxprt;
206 	struct rpc_rqst		*rr_rqst;
207 	struct xdr_buf		rr_hdrbuf;
208 	struct xdr_stream	rr_stream;
209 	struct llist_node	rr_node;
210 	struct ib_recv_wr	rr_recv_wr;
211 	struct list_head	rr_all;
212 };
213 
214 /* To reduce the rate at which a transport invokes ib_post_recv
215  * (and thus the hardware doorbell rate), xprtrdma posts Receive
216  * WRs in batches.
217  *
218  * Setting this to zero disables Receive post batching.
219  */
220 enum {
221 	RPCRDMA_MAX_RECV_BATCH = 7,
222 };
223 
224 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
225  */
226 struct rpcrdma_req;
227 struct rpcrdma_sendctx {
228 	struct ib_cqe		sc_cqe;
229 	struct rpc_rdma_cid	sc_cid;
230 	struct rpcrdma_req	*sc_req;
231 	unsigned int		sc_unmap_count;
232 	struct ib_sge		sc_sges[];
233 };
234 
235 /*
236  * struct rpcrdma_mr - external memory region metadata
237  *
238  * An external memory region is any buffer or page that is registered
239  * on the fly (ie, not pre-registered).
240  */
241 struct rpcrdma_req;
242 struct rpcrdma_mr {
243 	struct list_head	mr_list;
244 	struct rpcrdma_req	*mr_req;
245 
246 	struct ib_mr		*mr_ibmr;
247 	struct ib_device	*mr_device;
248 	struct scatterlist	*mr_sg;
249 	int			mr_nents;
250 	enum dma_data_direction	mr_dir;
251 	struct ib_cqe		mr_cqe;
252 	struct completion	mr_linv_done;
253 	union {
254 		struct ib_reg_wr	mr_regwr;
255 		struct ib_send_wr	mr_invwr;
256 	};
257 	struct rpcrdma_xprt	*mr_xprt;
258 	u32			mr_handle;
259 	u32			mr_length;
260 	u64			mr_offset;
261 	struct list_head	mr_all;
262 	struct rpc_rdma_cid	mr_cid;
263 };
264 
265 /*
266  * struct rpcrdma_req -- structure central to the request/reply sequence.
267  *
268  * N of these are associated with a transport instance, and stored in
269  * struct rpcrdma_buffer. N is the max number of outstanding requests.
270  *
271  * It includes pre-registered buffer memory for send AND recv.
272  * The recv buffer, however, is not owned by this structure, and
273  * is "donated" to the hardware when a recv is posted. When a
274  * reply is handled, the recv buffer used is given back to the
275  * struct rpcrdma_req associated with the request.
276  *
277  * In addition to the basic memory, this structure includes an array
278  * of iovs for send operations. The reason is that the iovs passed to
279  * ib_post_{send,recv} must not be modified until the work request
280  * completes.
281  */
282 
283 /* Maximum number of page-sized "segments" per chunk list to be
284  * registered or invalidated. Must handle a Reply chunk:
285  */
286 enum {
287 	RPCRDMA_MAX_IOV_SEGS	= 3,	/* head, page-boundary, tail */
288 	RPCRDMA_MAX_DATA_SEGS	= ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
289 	RPCRDMA_MAX_SEGS	= RPCRDMA_MAX_DATA_SEGS +
290 				  RPCRDMA_MAX_IOV_SEGS,
291 };
292 
293 /**
294  * struct rpcrdma_xdr_cursor - tracks position within an xdr_buf
295  *     for iterative MR registration
296  * @xc_buf: the xdr_buf being iterated
297  * @xc_page_offset: byte offset into the page region consumed so far
298  * @xc_flags: combination of XC_* bits
299  *
300  * Each XC_*_DONE flag indicates that this region has no
301  * remaining MR registration work.  That condition holds both when the region
302  * has already been registered by a prior frwr_map() call and
303  * when the region is excluded from this chunk type (pre-set
304  * at init time by rpcrdma_xdr_cursor_init()).  frwr_map()
305  * treats the two cases identically: skip the region.
306  */
307 struct rpcrdma_xdr_cursor {
308 	const struct xdr_buf		*xc_buf;
309 	unsigned int			xc_page_offset;
310 	unsigned int			xc_flags;
311 };
312 
313 #define XC_HEAD_DONE	BIT(0)
314 #define XC_PAGES_DONE	BIT(1)
315 #define XC_TAIL_DONE	BIT(2)
316 
317 /* The Send SGE array is provisioned to send a maximum size
318  * inline request:
319  * - RPC-over-RDMA header
320  * - xdr_buf head iovec
321  * - RPCRDMA_MAX_INLINE bytes, in pages
322  * - xdr_buf tail iovec
323  *
324  * The actual number of array elements consumed by each RPC
325  * depends on the device's max_sge limit.
326  */
327 enum {
328 	RPCRDMA_MIN_SEND_SGES = 3,
329 	RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
330 	RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
331 };
332 
333 struct rpcrdma_buffer;
334 struct rpcrdma_req {
335 	struct list_head	rl_list;
336 	struct rpc_rqst		rl_slot;
337 	struct rpcrdma_rep	*rl_reply;
338 	struct xdr_stream	rl_stream;
339 	struct xdr_buf		rl_hdrbuf;
340 	struct ib_send_wr	rl_wr;
341 	struct rpcrdma_sendctx	*rl_sendctx;
342 	struct rpcrdma_regbuf	*rl_rdmabuf;	/* xprt header */
343 	struct rpcrdma_regbuf	*rl_sendbuf;	/* rq_snd_buf */
344 	struct rpcrdma_regbuf	*rl_recvbuf;	/* rq_rcv_buf */
345 
346 	struct list_head	rl_all;
347 	struct kref		rl_kref;
348 
349 	struct list_head	rl_free_mrs;
350 	struct list_head	rl_registered;
351 };
352 
353 static inline struct rpcrdma_req *
rpcr_to_rdmar(const struct rpc_rqst * rqst)354 rpcr_to_rdmar(const struct rpc_rqst *rqst)
355 {
356 	return container_of(rqst, struct rpcrdma_req, rl_slot);
357 }
358 
359 static inline void
rpcrdma_mr_push(struct rpcrdma_mr * mr,struct list_head * list)360 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
361 {
362 	list_add(&mr->mr_list, list);
363 }
364 
365 static inline struct rpcrdma_mr *
rpcrdma_mr_pop(struct list_head * list)366 rpcrdma_mr_pop(struct list_head *list)
367 {
368 	struct rpcrdma_mr *mr;
369 
370 	mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list);
371 	if (mr)
372 		list_del_init(&mr->mr_list);
373 	return mr;
374 }
375 
376 /*
377  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
378  * inline requests/replies, and client/server credits.
379  *
380  * One of these is associated with a transport instance
381  */
382 struct rpcrdma_buffer {
383 	spinlock_t		rb_lock;
384 	struct list_head	rb_send_bufs;
385 	struct list_head	rb_mrs;
386 
387 	unsigned long		rb_sc_head;
388 	unsigned long		rb_sc_tail;
389 	unsigned long		rb_sc_last;
390 	struct rpcrdma_sendctx	**rb_sc_ctxs;
391 
392 	struct list_head	rb_allreqs;
393 	struct list_head	rb_all_mrs;
394 	struct list_head	rb_all_reps;
395 
396 	struct llist_head	rb_free_reps;
397 
398 	__be32			rb_max_requests;
399 	u32			rb_credits;	/* most recent credit grant */
400 
401 	u32			rb_bc_srv_max_requests;
402 	u32			rb_bc_max_requests;
403 
404 	struct work_struct	rb_refresh_worker;
405 };
406 
407 /*
408  * Statistics for RPCRDMA
409  */
410 struct rpcrdma_stats {
411 	/* accessed when sending a call */
412 	unsigned long		read_chunk_count;
413 	unsigned long		write_chunk_count;
414 	unsigned long		reply_chunk_count;
415 	unsigned long long	total_rdma_request;
416 
417 	/* rarely accessed error counters */
418 	unsigned long long	pullup_copy_count;
419 	unsigned long		hardway_register_count;
420 	unsigned long		failed_marshal_count;
421 	unsigned long		bad_reply_count;
422 	unsigned long		mrs_recycled;
423 	unsigned long		mrs_orphaned;
424 	unsigned long		mrs_allocated;
425 	unsigned long		empty_sendctx_q;
426 
427 	/* accessed when receiving a reply */
428 	unsigned long long	total_rdma_reply;
429 	unsigned long long	fixup_copy_count;
430 	unsigned long		reply_waits_for_send;
431 	unsigned long		local_inv_needed;
432 	unsigned long		nomsg_call_count;
433 	unsigned long		bcall_count;
434 };
435 
436 /*
437  * RPCRDMA transport -- encapsulates the structures above for
438  * integration with RPC.
439  *
440  * The contained structures are embedded, not pointers,
441  * for convenience. This structure need not be visible externally.
442  *
443  * It is allocated and initialized during mount, and released
444  * during unmount.
445  */
446 struct rpcrdma_xprt {
447 	struct rpc_xprt		rx_xprt;
448 	struct rpcrdma_ep	*rx_ep;
449 	struct rpcrdma_buffer	rx_buf;
450 	struct delayed_work	rx_connect_worker;
451 	struct rpc_timeout	rx_timeout;
452 	struct rpcrdma_stats	rx_stats;
453 };
454 
455 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
456 
457 static inline const char *
rpcrdma_addrstr(const struct rpcrdma_xprt * r_xprt)458 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
459 {
460 	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
461 }
462 
463 static inline const char *
rpcrdma_portstr(const struct rpcrdma_xprt * r_xprt)464 rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
465 {
466 	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
467 }
468 
469 /* Setting this to 0 ensures interoperability with early servers.
470  * Setting this to 1 enhances unaligned read/write performance.
471  * Default is 0, see sysctl entry and rpc_rdma.c */
472 extern int xprt_rdma_pad_optimize;
473 
474 /* This setting controls the hunt for a supported memory
475  * registration strategy.
476  */
477 extern unsigned int xprt_rdma_memreg_strategy;
478 
479 /*
480  * Endpoint calls - xprtrdma/verbs.c
481  */
482 void rpcrdma_force_disconnect(struct rpcrdma_ep *ep);
483 void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc);
484 int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt);
485 void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt);
486 
487 void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed);
488 
489 /*
490  * Buffer calls - xprtrdma/verbs.c
491  */
492 struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt,
493 				       size_t size);
494 int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
495 void rpcrdma_req_destroy(struct rpcrdma_req *req);
496 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
497 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
498 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
499 
500 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
501 void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt);
502 
503 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
504 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
505 			struct rpcrdma_req *req);
506 void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep);
507 void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req);
508 
509 bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
510 			    gfp_t flags);
511 bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
512 			      struct rpcrdma_regbuf *rb);
513 
514 /**
515  * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped
516  *
517  * Returns true if the buffer is now mapped to rb->rg_device.
518  */
rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf * rb)519 static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
520 {
521 	return rb->rg_device != NULL;
522 }
523 
524 /**
525  * rpcrdma_regbuf_dma_map - DMA-map a regbuf
526  * @r_xprt: controlling transport instance
527  * @rb: regbuf to be mapped
528  *
529  * Returns true if the buffer is currently DMA mapped.
530  */
rpcrdma_regbuf_dma_map(struct rpcrdma_xprt * r_xprt,struct rpcrdma_regbuf * rb)531 static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
532 					  struct rpcrdma_regbuf *rb)
533 {
534 	if (likely(rpcrdma_regbuf_is_mapped(rb)))
535 		return true;
536 	return __rpcrdma_regbuf_dma_map(r_xprt, rb);
537 }
538 
539 /*
540  * Wrappers for chunk registration, shared by read/write chunk code.
541  */
542 
543 static inline enum dma_data_direction
rpcrdma_data_dir(bool writing)544 rpcrdma_data_dir(bool writing)
545 {
546 	return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
547 }
548 
549 /* Memory registration calls xprtrdma/frwr_ops.c
550  */
551 void frwr_reset(struct rpcrdma_req *req);
552 int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device);
553 int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr);
554 void frwr_mr_release(struct rpcrdma_mr *mr);
555 int frwr_map(struct rpcrdma_xprt *r_xprt,
556 	     struct rpcrdma_xdr_cursor *cur,
557 	     bool writing, __be32 xid,
558 	     struct rpcrdma_mr *mr);
559 int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
560 void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
561 void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
562 void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
563 int frwr_wp_create(struct rpcrdma_xprt *r_xprt);
564 
565 /*
566  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
567  */
568 
569 enum rpcrdma_chunktype {
570 	rpcrdma_noch = 0,
571 	rpcrdma_noch_pullup,
572 	rpcrdma_noch_mapped,
573 	rpcrdma_readch,
574 	rpcrdma_areadch,
575 	rpcrdma_writech,
576 	rpcrdma_replych
577 };
578 
579 int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
580 			      struct rpcrdma_req *req, u32 hdrlen,
581 			      struct xdr_buf *xdr,
582 			      enum rpcrdma_chunktype rtype);
583 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
584 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
585 void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep);
586 void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt);
587 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
588 void rpcrdma_unpin_rqst(struct rpcrdma_rep *rep);
589 void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
590 
rpcrdma_set_xdrlen(struct xdr_buf * xdr,size_t len)591 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
592 {
593 	xdr->head[0].iov_len = len;
594 	xdr->len = len;
595 }
596 
597 /* RPC/RDMA module init - xprtrdma/transport.c
598  */
599 extern unsigned int xprt_rdma_max_inline_read;
600 extern unsigned int xprt_rdma_max_inline_write;
601 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
602 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
603 void xprt_rdma_close(struct rpc_xprt *xprt);
604 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
605 int xprt_rdma_init(void);
606 void xprt_rdma_cleanup(void);
607 
608 /* Backchannel calls - xprtrdma/backchannel.c
609  */
610 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
611 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
612 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
613 unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
614 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
615 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
616 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
617 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
618 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
619 
620 extern struct xprt_class xprt_rdma_bc;
621 
622 #endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */
623