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