xref: /openbmc/linux/net/sunrpc/xprtrdma/xprt_rdma.h (revision 8dd99871)
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/workqueue.h>		/* struct work_struct */
49 
50 #include <rdma/rdma_cm.h>		/* RDMA connection api */
51 #include <rdma/ib_verbs.h>		/* RDMA verbs api */
52 
53 #include <linux/sunrpc/clnt.h> 		/* rpc_xprt */
54 #include <linux/sunrpc/rpc_rdma.h> 	/* RPC/RDMA protocol */
55 #include <linux/sunrpc/xprtrdma.h> 	/* xprt parameters */
56 
57 #define RDMA_RESOLVE_TIMEOUT	(5000)	/* 5 seconds */
58 #define RDMA_CONNECT_RETRY_MAX	(2)	/* retries if no listener backlog */
59 
60 #define RPCRDMA_BIND_TO		(60U * HZ)
61 #define RPCRDMA_INIT_REEST_TO	(5U * HZ)
62 #define RPCRDMA_MAX_REEST_TO	(30U * HZ)
63 #define RPCRDMA_IDLE_DISC_TO	(5U * 60 * HZ)
64 
65 /*
66  * Interface Adapter -- one per transport instance
67  */
68 struct rpcrdma_ia {
69 	const struct rpcrdma_memreg_ops	*ri_ops;
70 	struct ib_device	*ri_device;
71 	struct rdma_cm_id 	*ri_id;
72 	struct ib_pd		*ri_pd;
73 	struct completion	ri_done;
74 	struct completion	ri_remove_done;
75 	int			ri_async_rc;
76 	unsigned int		ri_max_segs;
77 	unsigned int		ri_max_frwr_depth;
78 	unsigned int		ri_max_inline_write;
79 	unsigned int		ri_max_inline_read;
80 	unsigned int		ri_max_send_sges;
81 	bool			ri_implicit_roundup;
82 	enum ib_mr_type		ri_mrtype;
83 	unsigned long		ri_flags;
84 	struct ib_qp_attr	ri_qp_attr;
85 	struct ib_qp_init_attr	ri_qp_init_attr;
86 };
87 
88 enum {
89 	RPCRDMA_IAF_REMOVING = 0,
90 };
91 
92 /*
93  * RDMA Endpoint -- one per transport instance
94  */
95 
96 struct rpcrdma_ep {
97 	unsigned int		rep_send_count;
98 	unsigned int		rep_send_batch;
99 	int			rep_connected;
100 	struct ib_qp_init_attr	rep_attr;
101 	wait_queue_head_t 	rep_connect_wait;
102 	struct rpcrdma_connect_private	rep_cm_private;
103 	struct rdma_conn_param	rep_remote_cma;
104 	struct delayed_work	rep_connect_worker;
105 };
106 
107 /* Pre-allocate extra Work Requests for handling backward receives
108  * and sends. This is a fixed value because the Work Queues are
109  * allocated when the forward channel is set up.
110  */
111 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
112 #define RPCRDMA_BACKWARD_WRS		(8)
113 #else
114 #define RPCRDMA_BACKWARD_WRS		(0)
115 #endif
116 
117 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV
118  *
119  * The below structure appears at the front of a large region of kmalloc'd
120  * memory, which always starts on a good alignment boundary.
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 	__be32			rg_base[0] __attribute__ ((aligned(256)));
128 };
129 
130 static inline u64
131 rdmab_addr(struct rpcrdma_regbuf *rb)
132 {
133 	return rb->rg_iov.addr;
134 }
135 
136 static inline u32
137 rdmab_length(struct rpcrdma_regbuf *rb)
138 {
139 	return rb->rg_iov.length;
140 }
141 
142 static inline u32
143 rdmab_lkey(struct rpcrdma_regbuf *rb)
144 {
145 	return rb->rg_iov.lkey;
146 }
147 
148 static inline struct ib_device *
149 rdmab_device(struct rpcrdma_regbuf *rb)
150 {
151 	return rb->rg_device;
152 }
153 
154 #define RPCRDMA_DEF_GFP		(GFP_NOIO | __GFP_NOWARN)
155 
156 /* To ensure a transport can always make forward progress,
157  * the number of RDMA segments allowed in header chunk lists
158  * is capped at 8. This prevents less-capable devices and
159  * memory registrations from overrunning the Send buffer
160  * while building chunk lists.
161  *
162  * Elements of the Read list take up more room than the
163  * Write list or Reply chunk. 8 read segments means the Read
164  * list (or Write list or Reply chunk) cannot consume more
165  * than
166  *
167  * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
168  *
169  * And the fixed part of the header is another 24 bytes.
170  *
171  * The smallest inline threshold is 1024 bytes, ensuring that
172  * at least 750 bytes are available for RPC messages.
173  */
174 enum {
175 	RPCRDMA_MAX_HDR_SEGS = 8,
176 	RPCRDMA_HDRBUF_SIZE = 256,
177 };
178 
179 /*
180  * struct rpcrdma_rep -- this structure encapsulates state required
181  * to receive and complete an RPC Reply, asychronously. It needs
182  * several pieces of state:
183  *
184  *   o receive buffer and ib_sge (donated to provider)
185  *   o status of receive (success or not, length, inv rkey)
186  *   o bookkeeping state to get run by reply handler (XDR stream)
187  *
188  * These structures are allocated during transport initialization.
189  * N of these are associated with a transport instance, managed by
190  * struct rpcrdma_buffer. N is the max number of outstanding RPCs.
191  */
192 
193 struct rpcrdma_rep {
194 	struct ib_cqe		rr_cqe;
195 	__be32			rr_xid;
196 	__be32			rr_vers;
197 	__be32			rr_proc;
198 	int			rr_wc_flags;
199 	u32			rr_inv_rkey;
200 	bool			rr_temp;
201 	struct rpcrdma_regbuf	*rr_rdmabuf;
202 	struct rpcrdma_xprt	*rr_rxprt;
203 	struct work_struct	rr_work;
204 	struct xdr_buf		rr_hdrbuf;
205 	struct xdr_stream	rr_stream;
206 	struct rpc_rqst		*rr_rqst;
207 	struct list_head	rr_list;
208 	struct ib_recv_wr	rr_recv_wr;
209 };
210 
211 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
212  */
213 struct rpcrdma_req;
214 struct rpcrdma_xprt;
215 struct rpcrdma_sendctx {
216 	struct ib_send_wr	sc_wr;
217 	struct ib_cqe		sc_cqe;
218 	struct rpcrdma_xprt	*sc_xprt;
219 	struct rpcrdma_req	*sc_req;
220 	unsigned int		sc_unmap_count;
221 	struct ib_sge		sc_sges[];
222 };
223 
224 /* Limit the number of SGEs that can be unmapped during one
225  * Send completion. This caps the amount of work a single
226  * completion can do before returning to the provider.
227  *
228  * Setting this to zero disables Send completion batching.
229  */
230 enum {
231 	RPCRDMA_MAX_SEND_BATCH = 7,
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  * Each rpcrdma_buffer has a list of free MWs anchored in rb_mrs. During
241  * call_allocate, rpcrdma_buffer_get() assigns one to each segment in
242  * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep
243  * track of registration metadata while each RPC is pending.
244  * rpcrdma_deregister_external() uses this metadata to unmap and
245  * release these resources when an RPC is complete.
246  */
247 enum rpcrdma_frwr_state {
248 	FRWR_IS_INVALID,	/* ready to be used */
249 	FRWR_IS_VALID,		/* in use */
250 	FRWR_FLUSHED_FR,	/* flushed FASTREG WR */
251 	FRWR_FLUSHED_LI,	/* flushed LOCALINV WR */
252 };
253 
254 struct rpcrdma_frwr {
255 	struct ib_mr			*fr_mr;
256 	struct ib_cqe			fr_cqe;
257 	enum rpcrdma_frwr_state		fr_state;
258 	struct completion		fr_linv_done;
259 	union {
260 		struct ib_reg_wr	fr_regwr;
261 		struct ib_send_wr	fr_invwr;
262 	};
263 };
264 
265 struct rpcrdma_fmr {
266 	struct ib_fmr		*fm_mr;
267 	u64			*fm_physaddrs;
268 };
269 
270 struct rpcrdma_mr {
271 	struct list_head	mr_list;
272 	struct scatterlist	*mr_sg;
273 	int			mr_nents;
274 	enum dma_data_direction	mr_dir;
275 	union {
276 		struct rpcrdma_fmr	fmr;
277 		struct rpcrdma_frwr	frwr;
278 	};
279 	struct rpcrdma_xprt	*mr_xprt;
280 	u32			mr_handle;
281 	u32			mr_length;
282 	u64			mr_offset;
283 	struct list_head	mr_all;
284 };
285 
286 /*
287  * struct rpcrdma_req -- structure central to the request/reply sequence.
288  *
289  * N of these are associated with a transport instance, and stored in
290  * struct rpcrdma_buffer. N is the max number of outstanding requests.
291  *
292  * It includes pre-registered buffer memory for send AND recv.
293  * The recv buffer, however, is not owned by this structure, and
294  * is "donated" to the hardware when a recv is posted. When a
295  * reply is handled, the recv buffer used is given back to the
296  * struct rpcrdma_req associated with the request.
297  *
298  * In addition to the basic memory, this structure includes an array
299  * of iovs for send operations. The reason is that the iovs passed to
300  * ib_post_{send,recv} must not be modified until the work request
301  * completes.
302  */
303 
304 /* Maximum number of page-sized "segments" per chunk list to be
305  * registered or invalidated. Must handle a Reply chunk:
306  */
307 enum {
308 	RPCRDMA_MAX_IOV_SEGS	= 3,
309 	RPCRDMA_MAX_DATA_SEGS	= ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
310 	RPCRDMA_MAX_SEGS	= RPCRDMA_MAX_DATA_SEGS +
311 				  RPCRDMA_MAX_IOV_SEGS,
312 };
313 
314 struct rpcrdma_mr_seg {		/* chunk descriptors */
315 	u32		mr_len;		/* length of chunk or segment */
316 	struct page	*mr_page;	/* owning page, if any */
317 	char		*mr_offset;	/* kva if no page, else offset */
318 };
319 
320 /* The Send SGE array is provisioned to send a maximum size
321  * inline request:
322  * - RPC-over-RDMA header
323  * - xdr_buf head iovec
324  * - RPCRDMA_MAX_INLINE bytes, in pages
325  * - xdr_buf tail iovec
326  *
327  * The actual number of array elements consumed by each RPC
328  * depends on the device's max_sge limit.
329  */
330 enum {
331 	RPCRDMA_MIN_SEND_SGES = 3,
332 	RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
333 	RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
334 };
335 
336 struct rpcrdma_buffer;
337 struct rpcrdma_req {
338 	struct list_head	rl_list;
339 	struct rpc_rqst		rl_slot;
340 	struct rpcrdma_buffer	*rl_buffer;
341 	struct rpcrdma_rep	*rl_reply;
342 	struct xdr_stream	rl_stream;
343 	struct xdr_buf		rl_hdrbuf;
344 	struct rpcrdma_sendctx	*rl_sendctx;
345 	struct rpcrdma_regbuf	*rl_rdmabuf;	/* xprt header */
346 	struct rpcrdma_regbuf	*rl_sendbuf;	/* rq_snd_buf */
347 	struct rpcrdma_regbuf	*rl_recvbuf;	/* rq_rcv_buf */
348 
349 	struct list_head	rl_all;
350 	unsigned long		rl_flags;
351 
352 	struct list_head	rl_registered;	/* registered segments */
353 	struct rpcrdma_mr_seg	rl_segments[RPCRDMA_MAX_SEGS];
354 };
355 
356 /* rl_flags */
357 enum {
358 	RPCRDMA_REQ_F_PENDING = 0,
359 	RPCRDMA_REQ_F_TX_RESOURCES,
360 };
361 
362 static inline struct rpcrdma_req *
363 rpcr_to_rdmar(const struct rpc_rqst *rqst)
364 {
365 	return container_of(rqst, struct rpcrdma_req, rl_slot);
366 }
367 
368 static inline void
369 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
370 {
371 	list_add_tail(&mr->mr_list, list);
372 }
373 
374 static inline struct rpcrdma_mr *
375 rpcrdma_mr_pop(struct list_head *list)
376 {
377 	struct rpcrdma_mr *mr;
378 
379 	mr = list_first_entry(list, struct rpcrdma_mr, mr_list);
380 	list_del_init(&mr->mr_list);
381 	return mr;
382 }
383 
384 /*
385  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
386  * inline requests/replies, and client/server credits.
387  *
388  * One of these is associated with a transport instance
389  */
390 struct rpcrdma_buffer {
391 	spinlock_t		rb_mrlock;	/* protect rb_mrs list */
392 	struct list_head	rb_mrs;
393 	struct list_head	rb_all;
394 
395 	unsigned long		rb_sc_head;
396 	unsigned long		rb_sc_tail;
397 	unsigned long		rb_sc_last;
398 	struct rpcrdma_sendctx	**rb_sc_ctxs;
399 
400 	spinlock_t		rb_lock;	/* protect buf lists */
401 	struct list_head	rb_send_bufs;
402 	struct list_head	rb_recv_bufs;
403 	unsigned long		rb_flags;
404 	u32			rb_max_requests;
405 	u32			rb_credits;	/* most recent credit grant */
406 	int			rb_posted_receives;
407 
408 	u32			rb_bc_srv_max_requests;
409 	spinlock_t		rb_reqslock;	/* protect rb_allreqs */
410 	struct list_head	rb_allreqs;
411 
412 	u32			rb_bc_max_requests;
413 
414 	spinlock_t		rb_recovery_lock; /* protect rb_stale_mrs */
415 	struct list_head	rb_stale_mrs;
416 	struct delayed_work	rb_recovery_worker;
417 	struct delayed_work	rb_refresh_worker;
418 };
419 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia)
420 
421 /* rb_flags */
422 enum {
423 	RPCRDMA_BUF_F_EMPTY_SCQ = 0,
424 };
425 
426 /*
427  * Internal structure for transport instance creation. This
428  * exists primarily for modularity.
429  *
430  * This data should be set with mount options
431  */
432 struct rpcrdma_create_data_internal {
433 	unsigned int	max_requests;	/* max requests (slots) in flight */
434 	unsigned int	rsize;		/* mount rsize - max read hdr+data */
435 	unsigned int	wsize;		/* mount wsize - max write hdr+data */
436 	unsigned int	inline_rsize;	/* max non-rdma read data payload */
437 	unsigned int	inline_wsize;	/* max non-rdma write data payload */
438 };
439 
440 /*
441  * Statistics for RPCRDMA
442  */
443 struct rpcrdma_stats {
444 	/* accessed when sending a call */
445 	unsigned long		read_chunk_count;
446 	unsigned long		write_chunk_count;
447 	unsigned long		reply_chunk_count;
448 	unsigned long long	total_rdma_request;
449 
450 	/* rarely accessed error counters */
451 	unsigned long long	pullup_copy_count;
452 	unsigned long		hardway_register_count;
453 	unsigned long		failed_marshal_count;
454 	unsigned long		bad_reply_count;
455 	unsigned long		mrs_recovered;
456 	unsigned long		mrs_orphaned;
457 	unsigned long		mrs_allocated;
458 	unsigned long		empty_sendctx_q;
459 
460 	/* accessed when receiving a reply */
461 	unsigned long long	total_rdma_reply;
462 	unsigned long long	fixup_copy_count;
463 	unsigned long		reply_waits_for_send;
464 	unsigned long		local_inv_needed;
465 	unsigned long		nomsg_call_count;
466 	unsigned long		bcall_count;
467 };
468 
469 /*
470  * Per-registration mode operations
471  */
472 struct rpcrdma_xprt;
473 struct rpcrdma_memreg_ops {
474 	struct rpcrdma_mr_seg *
475 			(*ro_map)(struct rpcrdma_xprt *,
476 				  struct rpcrdma_mr_seg *, int, bool,
477 				  struct rpcrdma_mr **);
478 	int		(*ro_send)(struct rpcrdma_ia *ia,
479 				   struct rpcrdma_req *req);
480 	void		(*ro_reminv)(struct rpcrdma_rep *rep,
481 				     struct list_head *mrs);
482 	void		(*ro_unmap_sync)(struct rpcrdma_xprt *,
483 					 struct list_head *);
484 	void		(*ro_recover_mr)(struct rpcrdma_mr *mr);
485 	int		(*ro_open)(struct rpcrdma_ia *,
486 				   struct rpcrdma_ep *,
487 				   struct rpcrdma_create_data_internal *);
488 	size_t		(*ro_maxpages)(struct rpcrdma_xprt *);
489 	int		(*ro_init_mr)(struct rpcrdma_ia *,
490 				      struct rpcrdma_mr *);
491 	void		(*ro_release_mr)(struct rpcrdma_mr *mr);
492 	const char	*ro_displayname;
493 	const int	ro_send_w_inv_ok;
494 };
495 
496 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops;
497 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops;
498 
499 /*
500  * RPCRDMA transport -- encapsulates the structures above for
501  * integration with RPC.
502  *
503  * The contained structures are embedded, not pointers,
504  * for convenience. This structure need not be visible externally.
505  *
506  * It is allocated and initialized during mount, and released
507  * during unmount.
508  */
509 struct rpcrdma_xprt {
510 	struct rpc_xprt		rx_xprt;
511 	struct rpcrdma_ia	rx_ia;
512 	struct rpcrdma_ep	rx_ep;
513 	struct rpcrdma_buffer	rx_buf;
514 	struct rpcrdma_create_data_internal rx_data;
515 	struct delayed_work	rx_connect_worker;
516 	struct rpcrdma_stats	rx_stats;
517 };
518 
519 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
520 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data)
521 
522 static inline const char *
523 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
524 {
525 	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
526 }
527 
528 static inline const char *
529 rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
530 {
531 	return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
532 }
533 
534 /* Setting this to 0 ensures interoperability with early servers.
535  * Setting this to 1 enhances certain unaligned read/write performance.
536  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
537 extern int xprt_rdma_pad_optimize;
538 
539 /* This setting controls the hunt for a supported memory
540  * registration strategy.
541  */
542 extern unsigned int xprt_rdma_memreg_strategy;
543 
544 /*
545  * Interface Adapter calls - xprtrdma/verbs.c
546  */
547 int rpcrdma_ia_open(struct rpcrdma_xprt *xprt);
548 void rpcrdma_ia_remove(struct rpcrdma_ia *ia);
549 void rpcrdma_ia_close(struct rpcrdma_ia *);
550 bool frwr_is_supported(struct rpcrdma_ia *);
551 bool fmr_is_supported(struct rpcrdma_ia *);
552 
553 extern struct workqueue_struct *rpcrdma_receive_wq;
554 
555 /*
556  * Endpoint calls - xprtrdma/verbs.c
557  */
558 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *,
559 				struct rpcrdma_create_data_internal *);
560 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *);
561 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *);
562 void rpcrdma_conn_func(struct rpcrdma_ep *ep);
563 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *);
564 
565 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *,
566 				struct rpcrdma_req *);
567 void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
568 
569 /*
570  * Buffer calls - xprtrdma/verbs.c
571  */
572 struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *);
573 void rpcrdma_destroy_req(struct rpcrdma_req *);
574 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
575 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
576 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_buffer *buf);
577 
578 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
579 void rpcrdma_mr_put(struct rpcrdma_mr *mr);
580 void rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr);
581 void rpcrdma_mr_defer_recovery(struct rpcrdma_mr *mr);
582 
583 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
584 void rpcrdma_buffer_put(struct rpcrdma_req *);
585 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
586 
587 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(size_t, enum dma_data_direction,
588 					    gfp_t);
589 bool __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *, struct rpcrdma_regbuf *);
590 void rpcrdma_free_regbuf(struct rpcrdma_regbuf *);
591 
592 static inline bool
593 rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
594 {
595 	return rb->rg_device != NULL;
596 }
597 
598 static inline bool
599 rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
600 {
601 	if (likely(rpcrdma_regbuf_is_mapped(rb)))
602 		return true;
603 	return __rpcrdma_dma_map_regbuf(ia, rb);
604 }
605 
606 int rpcrdma_alloc_wq(void);
607 void rpcrdma_destroy_wq(void);
608 
609 /*
610  * Wrappers for chunk registration, shared by read/write chunk code.
611  */
612 
613 static inline enum dma_data_direction
614 rpcrdma_data_dir(bool writing)
615 {
616 	return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
617 }
618 
619 /*
620  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
621  */
622 
623 enum rpcrdma_chunktype {
624 	rpcrdma_noch = 0,
625 	rpcrdma_readch,
626 	rpcrdma_areadch,
627 	rpcrdma_writech,
628 	rpcrdma_replych
629 };
630 
631 int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
632 			      struct rpcrdma_req *req, u32 hdrlen,
633 			      struct xdr_buf *xdr,
634 			      enum rpcrdma_chunktype rtype);
635 void rpcrdma_unmap_sendctx(struct rpcrdma_sendctx *sc);
636 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
637 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
638 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
639 void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
640 void rpcrdma_release_rqst(struct rpcrdma_xprt *r_xprt,
641 			  struct rpcrdma_req *req);
642 void rpcrdma_deferred_completion(struct work_struct *work);
643 
644 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
645 {
646 	xdr->head[0].iov_len = len;
647 	xdr->len = len;
648 }
649 
650 /* RPC/RDMA module init - xprtrdma/transport.c
651  */
652 extern unsigned int xprt_rdma_max_inline_read;
653 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
654 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
655 void rpcrdma_connect_worker(struct work_struct *work);
656 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
657 int xprt_rdma_init(void);
658 void xprt_rdma_cleanup(void);
659 
660 /* Backchannel calls - xprtrdma/backchannel.c
661  */
662 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
663 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
664 int xprt_rdma_bc_up(struct svc_serv *, struct net *);
665 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
666 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
667 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
668 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
669 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
670 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
671 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
672 
673 extern struct xprt_class xprt_rdma_bc;
674 
675 #endif				/* _LINUX_SUNRPC_XPRT_RDMA_H */
676