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.h> /* RPC/RDMA protocol */ 57#include <linux/sunrpc/xprtrdma.h> /* xprt parameters */ 58 59#define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */ 60#define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */ 61 62#define RPCRDMA_BIND_TO (60U * HZ) 63#define RPCRDMA_INIT_REEST_TO (5U * HZ) 64#define RPCRDMA_MAX_REEST_TO (30U * HZ) 65#define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ) 66 67/* 68 * RDMA Endpoint -- connection endpoint details 69 */ 70struct rpcrdma_ep { 71 struct kref re_kref; 72 struct rdma_cm_id *re_id; 73 struct ib_pd *re_pd; 74 unsigned int re_max_rdma_segs; 75 unsigned int re_max_fr_depth; 76 bool re_implicit_roundup; 77 enum ib_mr_type re_mrtype; 78 struct completion re_done; 79 unsigned int re_send_count; 80 unsigned int re_send_batch; 81 unsigned int re_max_inline_send; 82 unsigned int re_max_inline_recv; 83 int re_async_rc; 84 int re_connect_status; 85 atomic_t re_force_disconnect; 86 struct ib_qp_init_attr re_attr; 87 wait_queue_head_t re_connect_wait; 88 struct rpc_xprt *re_xprt; 89 struct rpcrdma_connect_private 90 re_cm_private; 91 struct rdma_conn_param re_remote_cma; 92 int re_receive_count; 93 unsigned int re_max_requests; /* depends on device */ 94 unsigned int re_inline_send; /* negotiated */ 95 unsigned int re_inline_recv; /* negotiated */ 96}; 97 98/* Pre-allocate extra Work Requests for handling backward receives 99 * and sends. This is a fixed value because the Work Queues are 100 * allocated when the forward channel is set up, long before the 101 * backchannel is provisioned. This value is two times 102 * NFS4_DEF_CB_SLOT_TABLE_SIZE. 103 */ 104#if defined(CONFIG_SUNRPC_BACKCHANNEL) 105#define RPCRDMA_BACKWARD_WRS (32) 106#else 107#define RPCRDMA_BACKWARD_WRS (0) 108#endif 109 110/* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV 111 */ 112 113struct rpcrdma_regbuf { 114 struct ib_sge rg_iov; 115 struct ib_device *rg_device; 116 enum dma_data_direction rg_direction; 117 void *rg_data; 118}; 119 120static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb) 121{ 122 return rb->rg_iov.addr; 123} 124 125static inline u32 rdmab_length(struct rpcrdma_regbuf *rb) 126{ 127 return rb->rg_iov.length; 128} 129 130static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb) 131{ 132 return rb->rg_iov.lkey; 133} 134 135static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb) 136{ 137 return rb->rg_device; 138} 139 140static inline void *rdmab_data(const struct rpcrdma_regbuf *rb) 141{ 142 return rb->rg_data; 143} 144 145#define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN) 146 147/* To ensure a transport can always make forward progress, 148 * the number of RDMA segments allowed in header chunk lists 149 * is capped at 16. This prevents less-capable devices from 150 * overrunning the Send buffer while building chunk lists. 151 * 152 * Elements of the Read list take up more room than the 153 * Write list or Reply chunk. 16 read segments means the 154 * chunk lists cannot consume more than 155 * 156 * ((16 + 2) * read segment size) + 1 XDR words, 157 * 158 * or about 400 bytes. The fixed part of the header is 159 * another 24 bytes. Thus when the inline threshold is 160 * 1024 bytes, at least 600 bytes are available for RPC 161 * message bodies. 162 */ 163enum { 164 RPCRDMA_MAX_HDR_SEGS = 16, 165}; 166 167/* 168 * struct rpcrdma_rep -- this structure encapsulates state required 169 * to receive and complete an RPC Reply, asychronously. It needs 170 * several pieces of state: 171 * 172 * o receive buffer and ib_sge (donated to provider) 173 * o status of receive (success or not, length, inv rkey) 174 * o bookkeeping state to get run by reply handler (XDR stream) 175 * 176 * These structures are allocated during transport initialization. 177 * N of these are associated with a transport instance, managed by 178 * struct rpcrdma_buffer. N is the max number of outstanding RPCs. 179 */ 180 181struct rpcrdma_rep { 182 struct ib_cqe rr_cqe; 183 __be32 rr_xid; 184 __be32 rr_vers; 185 __be32 rr_proc; 186 int rr_wc_flags; 187 u32 rr_inv_rkey; 188 bool rr_temp; 189 struct rpcrdma_regbuf *rr_rdmabuf; 190 struct rpcrdma_xprt *rr_rxprt; 191 struct rpc_rqst *rr_rqst; 192 struct xdr_buf rr_hdrbuf; 193 struct xdr_stream rr_stream; 194 struct llist_node rr_node; 195 struct ib_recv_wr rr_recv_wr; 196 struct list_head rr_all; 197}; 198 199/* To reduce the rate at which a transport invokes ib_post_recv 200 * (and thus the hardware doorbell rate), xprtrdma posts Receive 201 * WRs in batches. 202 * 203 * Setting this to zero disables Receive post batching. 204 */ 205enum { 206 RPCRDMA_MAX_RECV_BATCH = 7, 207}; 208 209/* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes 210 */ 211struct rpcrdma_req; 212struct rpcrdma_sendctx { 213 struct ib_cqe sc_cqe; 214 struct rpcrdma_req *sc_req; 215 unsigned int sc_unmap_count; 216 struct ib_sge sc_sges[]; 217}; 218 219/* 220 * struct rpcrdma_mr - external memory region metadata 221 * 222 * An external memory region is any buffer or page that is registered 223 * on the fly (ie, not pre-registered). 224 */ 225struct rpcrdma_frwr { 226 struct ib_mr *fr_mr; 227 struct ib_cqe fr_cqe; 228 struct completion fr_linv_done; 229 union { 230 struct ib_reg_wr fr_regwr; 231 struct ib_send_wr fr_invwr; 232 }; 233}; 234 235struct rpcrdma_req; 236struct rpcrdma_mr { 237 struct list_head mr_list; 238 struct rpcrdma_req *mr_req; 239 struct scatterlist *mr_sg; 240 int mr_nents; 241 enum dma_data_direction mr_dir; 242 struct rpcrdma_frwr frwr; 243 struct rpcrdma_xprt *mr_xprt; 244 u32 mr_handle; 245 u32 mr_length; 246 u64 mr_offset; 247 struct list_head mr_all; 248}; 249 250/* 251 * struct rpcrdma_req -- structure central to the request/reply sequence. 252 * 253 * N of these are associated with a transport instance, and stored in 254 * struct rpcrdma_buffer. N is the max number of outstanding requests. 255 * 256 * It includes pre-registered buffer memory for send AND recv. 257 * The recv buffer, however, is not owned by this structure, and 258 * is "donated" to the hardware when a recv is posted. When a 259 * reply is handled, the recv buffer used is given back to the 260 * struct rpcrdma_req associated with the request. 261 * 262 * In addition to the basic memory, this structure includes an array 263 * of iovs for send operations. The reason is that the iovs passed to 264 * ib_post_{send,recv} must not be modified until the work request 265 * completes. 266 */ 267 268/* Maximum number of page-sized "segments" per chunk list to be 269 * registered or invalidated. Must handle a Reply chunk: 270 */ 271enum { 272 RPCRDMA_MAX_IOV_SEGS = 3, 273 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1, 274 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS + 275 RPCRDMA_MAX_IOV_SEGS, 276}; 277 278struct rpcrdma_mr_seg { /* chunk descriptors */ 279 u32 mr_len; /* length of chunk or segment */ 280 struct page *mr_page; /* owning page, if any */ 281 char *mr_offset; /* kva if no page, else offset */ 282}; 283 284/* The Send SGE array is provisioned to send a maximum size 285 * inline request: 286 * - RPC-over-RDMA header 287 * - xdr_buf head iovec 288 * - RPCRDMA_MAX_INLINE bytes, in pages 289 * - xdr_buf tail iovec 290 * 291 * The actual number of array elements consumed by each RPC 292 * depends on the device's max_sge limit. 293 */ 294enum { 295 RPCRDMA_MIN_SEND_SGES = 3, 296 RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT, 297 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1, 298}; 299 300struct rpcrdma_buffer; 301struct rpcrdma_req { 302 struct list_head rl_list; 303 struct rpc_rqst rl_slot; 304 struct rpcrdma_rep *rl_reply; 305 struct xdr_stream rl_stream; 306 struct xdr_buf rl_hdrbuf; 307 struct ib_send_wr rl_wr; 308 struct rpcrdma_sendctx *rl_sendctx; 309 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */ 310 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */ 311 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */ 312 313 struct list_head rl_all; 314 struct kref rl_kref; 315 316 struct list_head rl_free_mrs; 317 struct list_head rl_registered; 318 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; 319}; 320 321static inline struct rpcrdma_req * 322rpcr_to_rdmar(const struct rpc_rqst *rqst) 323{ 324 return container_of(rqst, struct rpcrdma_req, rl_slot); 325} 326 327static inline void 328rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list) 329{ 330 list_add(&mr->mr_list, list); 331} 332 333static inline struct rpcrdma_mr * 334rpcrdma_mr_pop(struct list_head *list) 335{ 336 struct rpcrdma_mr *mr; 337 338 mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list); 339 if (mr) 340 list_del_init(&mr->mr_list); 341 return mr; 342} 343 344/* 345 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for 346 * inline requests/replies, and client/server credits. 347 * 348 * One of these is associated with a transport instance 349 */ 350struct rpcrdma_buffer { 351 spinlock_t rb_lock; 352 struct list_head rb_send_bufs; 353 struct list_head rb_mrs; 354 355 unsigned long rb_sc_head; 356 unsigned long rb_sc_tail; 357 unsigned long rb_sc_last; 358 struct rpcrdma_sendctx **rb_sc_ctxs; 359 360 struct list_head rb_allreqs; 361 struct list_head rb_all_mrs; 362 struct list_head rb_all_reps; 363 364 struct llist_head rb_free_reps; 365 366 __be32 rb_max_requests; 367 u32 rb_credits; /* most recent credit grant */ 368 369 u32 rb_bc_srv_max_requests; 370 u32 rb_bc_max_requests; 371 372 struct work_struct rb_refresh_worker; 373}; 374 375/* 376 * Statistics for RPCRDMA 377 */ 378struct rpcrdma_stats { 379 /* accessed when sending a call */ 380 unsigned long read_chunk_count; 381 unsigned long write_chunk_count; 382 unsigned long reply_chunk_count; 383 unsigned long long total_rdma_request; 384 385 /* rarely accessed error counters */ 386 unsigned long long pullup_copy_count; 387 unsigned long hardway_register_count; 388 unsigned long failed_marshal_count; 389 unsigned long bad_reply_count; 390 unsigned long mrs_recycled; 391 unsigned long mrs_orphaned; 392 unsigned long mrs_allocated; 393 unsigned long empty_sendctx_q; 394 395 /* accessed when receiving a reply */ 396 unsigned long long total_rdma_reply; 397 unsigned long long fixup_copy_count; 398 unsigned long reply_waits_for_send; 399 unsigned long local_inv_needed; 400 unsigned long nomsg_call_count; 401 unsigned long bcall_count; 402}; 403 404/* 405 * RPCRDMA transport -- encapsulates the structures above for 406 * integration with RPC. 407 * 408 * The contained structures are embedded, not pointers, 409 * for convenience. This structure need not be visible externally. 410 * 411 * It is allocated and initialized during mount, and released 412 * during unmount. 413 */ 414struct rpcrdma_xprt { 415 struct rpc_xprt rx_xprt; 416 struct rpcrdma_ep *rx_ep; 417 struct rpcrdma_buffer rx_buf; 418 struct delayed_work rx_connect_worker; 419 struct rpc_timeout rx_timeout; 420 struct rpcrdma_stats rx_stats; 421}; 422 423#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt) 424 425static inline const char * 426rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt) 427{ 428 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR]; 429} 430 431static inline const char * 432rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt) 433{ 434 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT]; 435} 436 437/* Setting this to 0 ensures interoperability with early servers. 438 * Setting this to 1 enhances certain unaligned read/write performance. 439 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */ 440extern int xprt_rdma_pad_optimize; 441 442/* This setting controls the hunt for a supported memory 443 * registration strategy. 444 */ 445extern unsigned int xprt_rdma_memreg_strategy; 446 447/* 448 * Endpoint calls - xprtrdma/verbs.c 449 */ 450void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc); 451int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt); 452void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt); 453 454int rpcrdma_post_sends(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 455void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp); 456 457/* 458 * Buffer calls - xprtrdma/verbs.c 459 */ 460struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size, 461 gfp_t flags); 462int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 463void rpcrdma_req_destroy(struct rpcrdma_req *req); 464int rpcrdma_buffer_create(struct rpcrdma_xprt *); 465void rpcrdma_buffer_destroy(struct rpcrdma_buffer *); 466struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt); 467 468struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt); 469void rpcrdma_mr_put(struct rpcrdma_mr *mr); 470void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt); 471 472struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); 473void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, 474 struct rpcrdma_req *req); 475void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req); 476void rpcrdma_recv_buffer_put(struct rpcrdma_rep *); 477 478bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, 479 gfp_t flags); 480bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, 481 struct rpcrdma_regbuf *rb); 482 483/** 484 * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped 485 * 486 * Returns true if the buffer is now mapped to rb->rg_device. 487 */ 488static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb) 489{ 490 return rb->rg_device != NULL; 491} 492 493/** 494 * rpcrdma_regbuf_dma_map - DMA-map a regbuf 495 * @r_xprt: controlling transport instance 496 * @rb: regbuf to be mapped 497 * 498 * Returns true if the buffer is currently DMA mapped. 499 */ 500static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, 501 struct rpcrdma_regbuf *rb) 502{ 503 if (likely(rpcrdma_regbuf_is_mapped(rb))) 504 return true; 505 return __rpcrdma_regbuf_dma_map(r_xprt, rb); 506} 507 508/* 509 * Wrappers for chunk registration, shared by read/write chunk code. 510 */ 511 512static inline enum dma_data_direction 513rpcrdma_data_dir(bool writing) 514{ 515 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 516} 517 518/* Memory registration calls xprtrdma/frwr_ops.c 519 */ 520void frwr_reset(struct rpcrdma_req *req); 521int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device); 522int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr); 523void frwr_release_mr(struct rpcrdma_mr *mr); 524struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, 525 struct rpcrdma_mr_seg *seg, 526 int nsegs, bool writing, __be32 xid, 527 struct rpcrdma_mr *mr); 528int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 529void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs); 530void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 531void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 532 533/* 534 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c 535 */ 536 537enum rpcrdma_chunktype { 538 rpcrdma_noch = 0, 539 rpcrdma_noch_pullup, 540 rpcrdma_noch_mapped, 541 rpcrdma_readch, 542 rpcrdma_areadch, 543 rpcrdma_writech, 544 rpcrdma_replych 545}; 546 547int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt, 548 struct rpcrdma_req *req, u32 hdrlen, 549 struct xdr_buf *xdr, 550 enum rpcrdma_chunktype rtype); 551void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc); 552int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst); 553void rpcrdma_set_max_header_sizes(struct rpcrdma_ep *ep); 554void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt); 555void rpcrdma_complete_rqst(struct rpcrdma_rep *rep); 556void rpcrdma_reply_handler(struct rpcrdma_rep *rep); 557 558static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len) 559{ 560 xdr->head[0].iov_len = len; 561 xdr->len = len; 562} 563 564/* RPC/RDMA module init - xprtrdma/transport.c 565 */ 566extern unsigned int xprt_rdma_max_inline_read; 567extern unsigned int xprt_rdma_max_inline_write; 568void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap); 569void xprt_rdma_free_addresses(struct rpc_xprt *xprt); 570void xprt_rdma_close(struct rpc_xprt *xprt); 571void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq); 572int xprt_rdma_init(void); 573void xprt_rdma_cleanup(void); 574 575/* Backchannel calls - xprtrdma/backchannel.c 576 */ 577#if defined(CONFIG_SUNRPC_BACKCHANNEL) 578int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int); 579size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *); 580unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *); 581int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); 582void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *); 583int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst); 584void xprt_rdma_bc_free_rqst(struct rpc_rqst *); 585void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); 586#endif /* CONFIG_SUNRPC_BACKCHANNEL */ 587 588extern struct xprt_class xprt_rdma_bc; 589 590#endif /* _LINUX_SUNRPC_XPRT_RDMA_H */ 591