1 /* 2 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. 3 * 4 * This software is available to you under a choice of one of two 5 * licenses. You may choose to be licensed under the terms of the GNU 6 * General Public License (GPL) Version 2, available from the file 7 * COPYING in the main directory of this source tree, or the BSD-type 8 * license below: 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 17 * Redistributions in binary form must reproduce the above 18 * copyright notice, this list of conditions and the following 19 * disclaimer in the documentation and/or other materials provided 20 * with the distribution. 21 * 22 * Neither the name of the Network Appliance, Inc. nor the names of 23 * its contributors may be used to endorse or promote products 24 * derived from this software without specific prior written 25 * permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 #ifndef _LINUX_SUNRPC_XPRT_RDMA_H 41 #define _LINUX_SUNRPC_XPRT_RDMA_H 42 43 #include <linux/wait.h> /* wait_queue_head_t, etc */ 44 #include <linux/spinlock.h> /* spinlock_t, etc */ 45 #include <linux/atomic.h> /* atomic_t, etc */ 46 #include <linux/workqueue.h> /* struct work_struct */ 47 48 #include <rdma/rdma_cm.h> /* RDMA connection api */ 49 #include <rdma/ib_verbs.h> /* RDMA verbs api */ 50 51 #include <linux/sunrpc/clnt.h> /* rpc_xprt */ 52 #include <linux/sunrpc/rpc_rdma.h> /* RPC/RDMA protocol */ 53 #include <linux/sunrpc/xprtrdma.h> /* xprt parameters */ 54 55 #define RDMA_RESOLVE_TIMEOUT (5000) /* 5 seconds */ 56 #define RDMA_CONNECT_RETRY_MAX (2) /* retries if no listener backlog */ 57 58 #define RPCRDMA_BIND_TO (60U * HZ) 59 #define RPCRDMA_INIT_REEST_TO (5U * HZ) 60 #define RPCRDMA_MAX_REEST_TO (30U * HZ) 61 #define RPCRDMA_IDLE_DISC_TO (5U * 60 * HZ) 62 63 /* 64 * Interface Adapter -- one per transport instance 65 */ 66 struct rpcrdma_ia { 67 const struct rpcrdma_memreg_ops *ri_ops; 68 struct ib_device *ri_device; 69 struct rdma_cm_id *ri_id; 70 struct ib_pd *ri_pd; 71 struct completion ri_done; 72 int ri_async_rc; 73 unsigned int ri_max_segs; 74 unsigned int ri_max_frmr_depth; 75 unsigned int ri_max_inline_write; 76 unsigned int ri_max_inline_read; 77 bool ri_reminv_expected; 78 struct ib_qp_attr ri_qp_attr; 79 struct ib_qp_init_attr ri_qp_init_attr; 80 }; 81 82 /* 83 * RDMA Endpoint -- one per transport instance 84 */ 85 86 struct rpcrdma_ep { 87 atomic_t rep_cqcount; 88 int rep_cqinit; 89 int rep_connected; 90 struct ib_qp_init_attr rep_attr; 91 wait_queue_head_t rep_connect_wait; 92 struct rpcrdma_connect_private rep_cm_private; 93 struct rdma_conn_param rep_remote_cma; 94 struct sockaddr_storage rep_remote_addr; 95 struct delayed_work rep_connect_worker; 96 }; 97 98 #define INIT_CQCOUNT(ep) atomic_set(&(ep)->rep_cqcount, (ep)->rep_cqinit) 99 #define DECR_CQCOUNT(ep) atomic_sub_return(1, &(ep)->rep_cqcount) 100 101 /* Pre-allocate extra Work Requests for handling backward receives 102 * and sends. This is a fixed value because the Work Queues are 103 * allocated when the forward channel is set up. 104 */ 105 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 106 #define RPCRDMA_BACKWARD_WRS (8) 107 #else 108 #define RPCRDMA_BACKWARD_WRS (0) 109 #endif 110 111 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV 112 * 113 * The below structure appears at the front of a large region of kmalloc'd 114 * memory, which always starts on a good alignment boundary. 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 __be32 rg_base[0] __attribute__ ((aligned(256))); 122 }; 123 124 static inline u64 125 rdmab_addr(struct rpcrdma_regbuf *rb) 126 { 127 return rb->rg_iov.addr; 128 } 129 130 static inline u32 131 rdmab_length(struct rpcrdma_regbuf *rb) 132 { 133 return rb->rg_iov.length; 134 } 135 136 static inline u32 137 rdmab_lkey(struct rpcrdma_regbuf *rb) 138 { 139 return rb->rg_iov.lkey; 140 } 141 142 static inline struct rpcrdma_msg * 143 rdmab_to_msg(struct rpcrdma_regbuf *rb) 144 { 145 return (struct rpcrdma_msg *)rb->rg_base; 146 } 147 148 #define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN) 149 150 /* To ensure a transport can always make forward progress, 151 * the number of RDMA segments allowed in header chunk lists 152 * is capped at 8. This prevents less-capable devices and 153 * memory registrations from overrunning the Send buffer 154 * while building chunk lists. 155 * 156 * Elements of the Read list take up more room than the 157 * Write list or Reply chunk. 8 read segments means the Read 158 * list (or Write list or Reply chunk) cannot consume more 159 * than 160 * 161 * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes. 162 * 163 * And the fixed part of the header is another 24 bytes. 164 * 165 * The smallest inline threshold is 1024 bytes, ensuring that 166 * at least 750 bytes are available for RPC messages. 167 */ 168 enum { 169 RPCRDMA_MAX_HDR_SEGS = 8, 170 RPCRDMA_HDRBUF_SIZE = 256, 171 }; 172 173 /* 174 * struct rpcrdma_rep -- this structure encapsulates state required to recv 175 * and complete a reply, asychronously. It needs several pieces of 176 * state: 177 * o recv buffer (posted to provider) 178 * o ib_sge (also donated to provider) 179 * o status of reply (length, success or not) 180 * o bookkeeping state to get run by reply handler (list, etc) 181 * 182 * These are allocated during initialization, per-transport instance. 183 * 184 * N of these are associated with a transport instance, and stored in 185 * struct rpcrdma_buffer. N is the max number of outstanding requests. 186 */ 187 188 struct rpcrdma_rep { 189 struct ib_cqe rr_cqe; 190 unsigned int rr_len; 191 int rr_wc_flags; 192 u32 rr_inv_rkey; 193 struct ib_device *rr_device; 194 struct rpcrdma_xprt *rr_rxprt; 195 struct work_struct rr_work; 196 struct list_head rr_list; 197 struct ib_recv_wr rr_recv_wr; 198 struct rpcrdma_regbuf *rr_rdmabuf; 199 }; 200 201 #define RPCRDMA_BAD_LEN (~0U) 202 203 /* 204 * struct rpcrdma_mw - external memory region metadata 205 * 206 * An external memory region is any buffer or page that is registered 207 * on the fly (ie, not pre-registered). 208 * 209 * Each rpcrdma_buffer has a list of free MWs anchored in rb_mws. During 210 * call_allocate, rpcrdma_buffer_get() assigns one to each segment in 211 * an rpcrdma_req. Then rpcrdma_register_external() grabs these to keep 212 * track of registration metadata while each RPC is pending. 213 * rpcrdma_deregister_external() uses this metadata to unmap and 214 * release these resources when an RPC is complete. 215 */ 216 enum rpcrdma_frmr_state { 217 FRMR_IS_INVALID, /* ready to be used */ 218 FRMR_IS_VALID, /* in use */ 219 FRMR_IS_STALE, /* failed completion */ 220 }; 221 222 struct rpcrdma_frmr { 223 struct ib_mr *fr_mr; 224 struct ib_cqe fr_cqe; 225 enum rpcrdma_frmr_state fr_state; 226 struct completion fr_linv_done; 227 union { 228 struct ib_reg_wr fr_regwr; 229 struct ib_send_wr fr_invwr; 230 }; 231 }; 232 233 struct rpcrdma_fmr { 234 struct ib_fmr *fm_mr; 235 u64 *fm_physaddrs; 236 }; 237 238 struct rpcrdma_mw { 239 struct list_head mw_list; 240 struct scatterlist *mw_sg; 241 int mw_nents; 242 enum dma_data_direction mw_dir; 243 union { 244 struct rpcrdma_fmr fmr; 245 struct rpcrdma_frmr frmr; 246 }; 247 struct rpcrdma_xprt *mw_xprt; 248 u32 mw_handle; 249 u32 mw_length; 250 u64 mw_offset; 251 struct list_head mw_all; 252 }; 253 254 /* 255 * struct rpcrdma_req -- structure central to the request/reply sequence. 256 * 257 * N of these are associated with a transport instance, and stored in 258 * struct rpcrdma_buffer. N is the max number of outstanding requests. 259 * 260 * It includes pre-registered buffer memory for send AND recv. 261 * The recv buffer, however, is not owned by this structure, and 262 * is "donated" to the hardware when a recv is posted. When a 263 * reply is handled, the recv buffer used is given back to the 264 * struct rpcrdma_req associated with the request. 265 * 266 * In addition to the basic memory, this structure includes an array 267 * of iovs for send operations. The reason is that the iovs passed to 268 * ib_post_{send,recv} must not be modified until the work request 269 * completes. 270 */ 271 272 /* Maximum number of page-sized "segments" per chunk list to be 273 * registered or invalidated. Must handle a Reply chunk: 274 */ 275 enum { 276 RPCRDMA_MAX_IOV_SEGS = 3, 277 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1, 278 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS + 279 RPCRDMA_MAX_IOV_SEGS, 280 }; 281 282 struct rpcrdma_mr_seg { /* chunk descriptors */ 283 u32 mr_len; /* length of chunk or segment */ 284 struct page *mr_page; /* owning page, if any */ 285 char *mr_offset; /* kva if no page, else offset */ 286 }; 287 288 /* Reserve enough Send SGEs to send a maximum size inline request: 289 * - RPC-over-RDMA header 290 * - xdr_buf head iovec 291 * - RPCRDMA_MAX_INLINE bytes, possibly unaligned, in pages 292 * - xdr_buf tail iovec 293 */ 294 enum { 295 RPCRDMA_MAX_SEND_PAGES = PAGE_SIZE + RPCRDMA_MAX_INLINE - 1, 296 RPCRDMA_MAX_PAGE_SGES = (RPCRDMA_MAX_SEND_PAGES >> PAGE_SHIFT) + 1, 297 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1, 298 }; 299 300 struct rpcrdma_buffer; 301 struct rpcrdma_req { 302 struct list_head rl_free; 303 unsigned int rl_mapped_sges; 304 unsigned int rl_connect_cookie; 305 struct rpcrdma_buffer *rl_buffer; 306 struct rpcrdma_rep *rl_reply; 307 struct ib_send_wr rl_send_wr; 308 struct ib_sge rl_send_sge[RPCRDMA_MAX_SEND_SGES]; 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 ib_cqe rl_cqe; 314 struct list_head rl_all; 315 bool rl_backchannel; 316 317 struct list_head rl_registered; /* registered segments */ 318 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; 319 }; 320 321 static inline void 322 rpcrdma_set_xprtdata(struct rpc_rqst *rqst, struct rpcrdma_req *req) 323 { 324 rqst->rq_xprtdata = req; 325 } 326 327 static inline struct rpcrdma_req * 328 rpcr_to_rdmar(struct rpc_rqst *rqst) 329 { 330 return rqst->rq_xprtdata; 331 } 332 333 /* 334 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for 335 * inline requests/replies, and client/server credits. 336 * 337 * One of these is associated with a transport instance 338 */ 339 struct rpcrdma_buffer { 340 spinlock_t rb_mwlock; /* protect rb_mws list */ 341 struct list_head rb_mws; 342 struct list_head rb_all; 343 char *rb_pool; 344 345 spinlock_t rb_lock; /* protect buf lists */ 346 int rb_send_count, rb_recv_count; 347 struct list_head rb_send_bufs; 348 struct list_head rb_recv_bufs; 349 u32 rb_max_requests; 350 atomic_t rb_credits; /* most recent credit grant */ 351 352 u32 rb_bc_srv_max_requests; 353 spinlock_t rb_reqslock; /* protect rb_allreqs */ 354 struct list_head rb_allreqs; 355 356 u32 rb_bc_max_requests; 357 358 spinlock_t rb_recovery_lock; /* protect rb_stale_mrs */ 359 struct list_head rb_stale_mrs; 360 struct delayed_work rb_recovery_worker; 361 struct delayed_work rb_refresh_worker; 362 }; 363 #define rdmab_to_ia(b) (&container_of((b), struct rpcrdma_xprt, rx_buf)->rx_ia) 364 365 /* 366 * Internal structure for transport instance creation. This 367 * exists primarily for modularity. 368 * 369 * This data should be set with mount options 370 */ 371 struct rpcrdma_create_data_internal { 372 struct sockaddr_storage addr; /* RDMA server address */ 373 unsigned int max_requests; /* max requests (slots) in flight */ 374 unsigned int rsize; /* mount rsize - max read hdr+data */ 375 unsigned int wsize; /* mount wsize - max write hdr+data */ 376 unsigned int inline_rsize; /* max non-rdma read data payload */ 377 unsigned int inline_wsize; /* max non-rdma write data payload */ 378 unsigned int padding; /* non-rdma write header padding */ 379 }; 380 381 /* 382 * Statistics for RPCRDMA 383 */ 384 struct rpcrdma_stats { 385 unsigned long read_chunk_count; 386 unsigned long write_chunk_count; 387 unsigned long reply_chunk_count; 388 389 unsigned long long total_rdma_request; 390 unsigned long long total_rdma_reply; 391 392 unsigned long long pullup_copy_count; 393 unsigned long long fixup_copy_count; 394 unsigned long hardway_register_count; 395 unsigned long failed_marshal_count; 396 unsigned long bad_reply_count; 397 unsigned long nomsg_call_count; 398 unsigned long bcall_count; 399 unsigned long mrs_recovered; 400 unsigned long mrs_orphaned; 401 unsigned long mrs_allocated; 402 unsigned long local_inv_needed; 403 }; 404 405 /* 406 * Per-registration mode operations 407 */ 408 struct rpcrdma_xprt; 409 struct rpcrdma_memreg_ops { 410 int (*ro_map)(struct rpcrdma_xprt *, 411 struct rpcrdma_mr_seg *, int, bool, 412 struct rpcrdma_mw **); 413 void (*ro_unmap_sync)(struct rpcrdma_xprt *, 414 struct rpcrdma_req *); 415 void (*ro_unmap_safe)(struct rpcrdma_xprt *, 416 struct rpcrdma_req *, bool); 417 void (*ro_recover_mr)(struct rpcrdma_mw *); 418 int (*ro_open)(struct rpcrdma_ia *, 419 struct rpcrdma_ep *, 420 struct rpcrdma_create_data_internal *); 421 size_t (*ro_maxpages)(struct rpcrdma_xprt *); 422 int (*ro_init_mr)(struct rpcrdma_ia *, 423 struct rpcrdma_mw *); 424 void (*ro_release_mr)(struct rpcrdma_mw *); 425 const char *ro_displayname; 426 const int ro_send_w_inv_ok; 427 }; 428 429 extern const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops; 430 extern const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops; 431 432 /* 433 * RPCRDMA transport -- encapsulates the structures above for 434 * integration with RPC. 435 * 436 * The contained structures are embedded, not pointers, 437 * for convenience. This structure need not be visible externally. 438 * 439 * It is allocated and initialized during mount, and released 440 * during unmount. 441 */ 442 struct rpcrdma_xprt { 443 struct rpc_xprt rx_xprt; 444 struct rpcrdma_ia rx_ia; 445 struct rpcrdma_ep rx_ep; 446 struct rpcrdma_buffer rx_buf; 447 struct rpcrdma_create_data_internal rx_data; 448 struct delayed_work rx_connect_worker; 449 struct rpcrdma_stats rx_stats; 450 }; 451 452 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt) 453 #define rpcx_to_rdmad(x) (rpcx_to_rdmax(x)->rx_data) 454 455 /* Setting this to 0 ensures interoperability with early servers. 456 * Setting this to 1 enhances certain unaligned read/write performance. 457 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */ 458 extern int xprt_rdma_pad_optimize; 459 460 /* 461 * Interface Adapter calls - xprtrdma/verbs.c 462 */ 463 int rpcrdma_ia_open(struct rpcrdma_xprt *, struct sockaddr *, int); 464 void rpcrdma_ia_close(struct rpcrdma_ia *); 465 bool frwr_is_supported(struct rpcrdma_ia *); 466 bool fmr_is_supported(struct rpcrdma_ia *); 467 468 /* 469 * Endpoint calls - xprtrdma/verbs.c 470 */ 471 int rpcrdma_ep_create(struct rpcrdma_ep *, struct rpcrdma_ia *, 472 struct rpcrdma_create_data_internal *); 473 void rpcrdma_ep_destroy(struct rpcrdma_ep *, struct rpcrdma_ia *); 474 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *); 475 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *); 476 477 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *, 478 struct rpcrdma_req *); 479 int rpcrdma_ep_post_recv(struct rpcrdma_ia *, struct rpcrdma_rep *); 480 481 /* 482 * Buffer calls - xprtrdma/verbs.c 483 */ 484 struct rpcrdma_req *rpcrdma_create_req(struct rpcrdma_xprt *); 485 struct rpcrdma_rep *rpcrdma_create_rep(struct rpcrdma_xprt *); 486 void rpcrdma_destroy_req(struct rpcrdma_req *); 487 int rpcrdma_buffer_create(struct rpcrdma_xprt *); 488 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *); 489 490 struct rpcrdma_mw *rpcrdma_get_mw(struct rpcrdma_xprt *); 491 void rpcrdma_put_mw(struct rpcrdma_xprt *, struct rpcrdma_mw *); 492 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); 493 void rpcrdma_buffer_put(struct rpcrdma_req *); 494 void rpcrdma_recv_buffer_get(struct rpcrdma_req *); 495 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *); 496 497 void rpcrdma_defer_mr_recovery(struct rpcrdma_mw *); 498 499 struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(size_t, enum dma_data_direction, 500 gfp_t); 501 bool __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *, struct rpcrdma_regbuf *); 502 void rpcrdma_free_regbuf(struct rpcrdma_regbuf *); 503 504 static inline bool 505 rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb) 506 { 507 return rb->rg_device != NULL; 508 } 509 510 static inline bool 511 rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb) 512 { 513 if (likely(rpcrdma_regbuf_is_mapped(rb))) 514 return true; 515 return __rpcrdma_dma_map_regbuf(ia, rb); 516 } 517 518 int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int); 519 520 int rpcrdma_alloc_wq(void); 521 void rpcrdma_destroy_wq(void); 522 523 /* 524 * Wrappers for chunk registration, shared by read/write chunk code. 525 */ 526 527 static inline enum dma_data_direction 528 rpcrdma_data_dir(bool writing) 529 { 530 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 531 } 532 533 /* 534 * RPC/RDMA connection management calls - xprtrdma/rpc_rdma.c 535 */ 536 void rpcrdma_connect_worker(struct work_struct *); 537 void rpcrdma_conn_func(struct rpcrdma_ep *); 538 void rpcrdma_reply_handler(struct work_struct *); 539 540 /* 541 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c 542 */ 543 544 enum rpcrdma_chunktype { 545 rpcrdma_noch = 0, 546 rpcrdma_readch, 547 rpcrdma_areadch, 548 rpcrdma_writech, 549 rpcrdma_replych 550 }; 551 552 bool rpcrdma_prepare_send_sges(struct rpcrdma_ia *, struct rpcrdma_req *, 553 u32, struct xdr_buf *, enum rpcrdma_chunktype); 554 void rpcrdma_unmap_sges(struct rpcrdma_ia *, struct rpcrdma_req *); 555 int rpcrdma_marshal_req(struct rpc_rqst *); 556 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *); 557 558 /* RPC/RDMA module init - xprtrdma/transport.c 559 */ 560 extern unsigned int xprt_rdma_max_inline_read; 561 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap); 562 void xprt_rdma_free_addresses(struct rpc_xprt *xprt); 563 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq); 564 int xprt_rdma_init(void); 565 void xprt_rdma_cleanup(void); 566 567 /* Backchannel calls - xprtrdma/backchannel.c 568 */ 569 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 570 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int); 571 int xprt_rdma_bc_up(struct svc_serv *, struct net *); 572 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *); 573 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); 574 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *); 575 int rpcrdma_bc_marshal_reply(struct rpc_rqst *); 576 void xprt_rdma_bc_free_rqst(struct rpc_rqst *); 577 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); 578 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 579 580 extern struct xprt_class xprt_rdma_bc; 581 582 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */ 583