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 * Interface Adapter -- one per transport instance 69 */ 70 struct rpcrdma_ia { 71 struct rdma_cm_id *ri_id; 72 struct ib_pd *ri_pd; 73 int ri_async_rc; 74 unsigned int ri_max_rdma_segs; 75 unsigned int ri_max_frwr_depth; 76 bool ri_implicit_roundup; 77 enum ib_mr_type ri_mrtype; 78 unsigned long ri_flags; 79 struct completion ri_done; 80 struct completion ri_remove_done; 81 }; 82 83 enum { 84 RPCRDMA_IAF_REMOVING = 0, 85 }; 86 87 /* 88 * RDMA Endpoint -- one per transport instance 89 */ 90 91 struct rpcrdma_ep { 92 unsigned int rep_send_count; 93 unsigned int rep_send_batch; 94 unsigned int rep_max_inline_send; 95 unsigned int rep_max_inline_recv; 96 int rep_connected; 97 struct ib_qp_init_attr rep_attr; 98 wait_queue_head_t rep_connect_wait; 99 struct rpcrdma_connect_private rep_cm_private; 100 struct rdma_conn_param rep_remote_cma; 101 unsigned int rep_max_requests; /* depends on device */ 102 unsigned int rep_inline_send; /* negotiated */ 103 unsigned int rep_inline_recv; /* negotiated */ 104 int rep_receive_count; 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, long before the 110 * backchannel is provisioned. This value is two times 111 * NFS4_DEF_CB_SLOT_TABLE_SIZE. 112 */ 113 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 114 #define RPCRDMA_BACKWARD_WRS (32) 115 #else 116 #define RPCRDMA_BACKWARD_WRS (0) 117 #endif 118 119 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV 120 */ 121 122 struct rpcrdma_regbuf { 123 struct ib_sge rg_iov; 124 struct ib_device *rg_device; 125 enum dma_data_direction rg_direction; 126 void *rg_data; 127 }; 128 129 static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb) 130 { 131 return rb->rg_iov.addr; 132 } 133 134 static inline u32 rdmab_length(struct rpcrdma_regbuf *rb) 135 { 136 return rb->rg_iov.length; 137 } 138 139 static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb) 140 { 141 return rb->rg_iov.lkey; 142 } 143 144 static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb) 145 { 146 return rb->rg_device; 147 } 148 149 static inline void *rdmab_data(const struct rpcrdma_regbuf *rb) 150 { 151 return rb->rg_data; 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 16. This prevents less-capable devices from 159 * overrunning the Send buffer while building chunk lists. 160 * 161 * Elements of the Read list take up more room than the 162 * Write list or Reply chunk. 16 read segments means the 163 * chunk lists cannot consume more than 164 * 165 * ((16 + 2) * read segment size) + 1 XDR words, 166 * 167 * or about 400 bytes. The fixed part of the header is 168 * another 24 bytes. Thus when the inline threshold is 169 * 1024 bytes, at least 600 bytes are available for RPC 170 * message bodies. 171 */ 172 enum { 173 RPCRDMA_MAX_HDR_SEGS = 16, 174 }; 175 176 /* 177 * struct rpcrdma_rep -- this structure encapsulates state required 178 * to receive and complete an RPC Reply, asychronously. It needs 179 * several pieces of state: 180 * 181 * o receive buffer and ib_sge (donated to provider) 182 * o status of receive (success or not, length, inv rkey) 183 * o bookkeeping state to get run by reply handler (XDR stream) 184 * 185 * These structures are allocated during transport initialization. 186 * N of these are associated with a transport instance, managed by 187 * struct rpcrdma_buffer. N is the max number of outstanding RPCs. 188 */ 189 190 struct rpcrdma_rep { 191 struct ib_cqe rr_cqe; 192 __be32 rr_xid; 193 __be32 rr_vers; 194 __be32 rr_proc; 195 int rr_wc_flags; 196 u32 rr_inv_rkey; 197 bool rr_temp; 198 struct rpcrdma_regbuf *rr_rdmabuf; 199 struct rpcrdma_xprt *rr_rxprt; 200 struct rpc_rqst *rr_rqst; 201 struct xdr_buf rr_hdrbuf; 202 struct xdr_stream rr_stream; 203 struct llist_node rr_node; 204 struct ib_recv_wr rr_recv_wr; 205 struct list_head rr_all; 206 }; 207 208 /* To reduce the rate at which a transport invokes ib_post_recv 209 * (and thus the hardware doorbell rate), xprtrdma posts Receive 210 * WRs in batches. 211 * 212 * Setting this to zero disables Receive post batching. 213 */ 214 enum { 215 RPCRDMA_MAX_RECV_BATCH = 7, 216 }; 217 218 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes 219 */ 220 struct rpcrdma_req; 221 struct rpcrdma_sendctx { 222 struct ib_cqe sc_cqe; 223 struct rpcrdma_req *sc_req; 224 unsigned int sc_unmap_count; 225 struct ib_sge sc_sges[]; 226 }; 227 228 /* 229 * struct rpcrdma_mr - external memory region metadata 230 * 231 * An external memory region is any buffer or page that is registered 232 * on the fly (ie, not pre-registered). 233 */ 234 struct rpcrdma_frwr { 235 struct ib_mr *fr_mr; 236 struct ib_cqe fr_cqe; 237 struct completion fr_linv_done; 238 union { 239 struct ib_reg_wr fr_regwr; 240 struct ib_send_wr fr_invwr; 241 }; 242 }; 243 244 struct rpcrdma_req; 245 struct rpcrdma_mr { 246 struct list_head mr_list; 247 struct rpcrdma_req *mr_req; 248 struct scatterlist *mr_sg; 249 int mr_nents; 250 enum dma_data_direction mr_dir; 251 struct rpcrdma_frwr frwr; 252 struct rpcrdma_xprt *mr_xprt; 253 u32 mr_handle; 254 u32 mr_length; 255 u64 mr_offset; 256 struct list_head mr_all; 257 }; 258 259 /* 260 * struct rpcrdma_req -- structure central to the request/reply sequence. 261 * 262 * N of these are associated with a transport instance, and stored in 263 * struct rpcrdma_buffer. N is the max number of outstanding requests. 264 * 265 * It includes pre-registered buffer memory for send AND recv. 266 * The recv buffer, however, is not owned by this structure, and 267 * is "donated" to the hardware when a recv is posted. When a 268 * reply is handled, the recv buffer used is given back to the 269 * struct rpcrdma_req associated with the request. 270 * 271 * In addition to the basic memory, this structure includes an array 272 * of iovs for send operations. The reason is that the iovs passed to 273 * ib_post_{send,recv} must not be modified until the work request 274 * completes. 275 */ 276 277 /* Maximum number of page-sized "segments" per chunk list to be 278 * registered or invalidated. Must handle a Reply chunk: 279 */ 280 enum { 281 RPCRDMA_MAX_IOV_SEGS = 3, 282 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1, 283 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS + 284 RPCRDMA_MAX_IOV_SEGS, 285 }; 286 287 struct rpcrdma_mr_seg { /* chunk descriptors */ 288 u32 mr_len; /* length of chunk or segment */ 289 struct page *mr_page; /* owning page, if any */ 290 char *mr_offset; /* kva if no page, else offset */ 291 }; 292 293 /* The Send SGE array is provisioned to send a maximum size 294 * inline request: 295 * - RPC-over-RDMA header 296 * - xdr_buf head iovec 297 * - RPCRDMA_MAX_INLINE bytes, in pages 298 * - xdr_buf tail iovec 299 * 300 * The actual number of array elements consumed by each RPC 301 * depends on the device's max_sge limit. 302 */ 303 enum { 304 RPCRDMA_MIN_SEND_SGES = 3, 305 RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT, 306 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1, 307 }; 308 309 struct rpcrdma_buffer; 310 struct rpcrdma_req { 311 struct list_head rl_list; 312 struct rpc_rqst rl_slot; 313 struct rpcrdma_rep *rl_reply; 314 struct xdr_stream rl_stream; 315 struct xdr_buf rl_hdrbuf; 316 struct ib_send_wr rl_wr; 317 struct rpcrdma_sendctx *rl_sendctx; 318 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */ 319 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */ 320 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */ 321 322 struct list_head rl_all; 323 struct kref rl_kref; 324 325 struct list_head rl_free_mrs; 326 struct list_head rl_registered; 327 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; 328 }; 329 330 static inline struct rpcrdma_req * 331 rpcr_to_rdmar(const struct rpc_rqst *rqst) 332 { 333 return container_of(rqst, struct rpcrdma_req, rl_slot); 334 } 335 336 static inline void 337 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list) 338 { 339 list_add(&mr->mr_list, list); 340 } 341 342 static inline struct rpcrdma_mr * 343 rpcrdma_mr_pop(struct list_head *list) 344 { 345 struct rpcrdma_mr *mr; 346 347 mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list); 348 if (mr) 349 list_del_init(&mr->mr_list); 350 return mr; 351 } 352 353 /* 354 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for 355 * inline requests/replies, and client/server credits. 356 * 357 * One of these is associated with a transport instance 358 */ 359 struct rpcrdma_buffer { 360 spinlock_t rb_lock; 361 struct list_head rb_send_bufs; 362 struct list_head rb_mrs; 363 364 unsigned long rb_sc_head; 365 unsigned long rb_sc_tail; 366 unsigned long rb_sc_last; 367 struct rpcrdma_sendctx **rb_sc_ctxs; 368 369 struct list_head rb_allreqs; 370 struct list_head rb_all_mrs; 371 struct list_head rb_all_reps; 372 373 struct llist_head rb_free_reps; 374 375 __be32 rb_max_requests; 376 u32 rb_credits; /* most recent credit grant */ 377 378 u32 rb_bc_srv_max_requests; 379 u32 rb_bc_max_requests; 380 381 struct work_struct rb_refresh_worker; 382 }; 383 384 /* 385 * Statistics for RPCRDMA 386 */ 387 struct rpcrdma_stats { 388 /* accessed when sending a call */ 389 unsigned long read_chunk_count; 390 unsigned long write_chunk_count; 391 unsigned long reply_chunk_count; 392 unsigned long long total_rdma_request; 393 394 /* rarely accessed error counters */ 395 unsigned long long pullup_copy_count; 396 unsigned long hardway_register_count; 397 unsigned long failed_marshal_count; 398 unsigned long bad_reply_count; 399 unsigned long mrs_recycled; 400 unsigned long mrs_orphaned; 401 unsigned long mrs_allocated; 402 unsigned long empty_sendctx_q; 403 404 /* accessed when receiving a reply */ 405 unsigned long long total_rdma_reply; 406 unsigned long long fixup_copy_count; 407 unsigned long reply_waits_for_send; 408 unsigned long local_inv_needed; 409 unsigned long nomsg_call_count; 410 unsigned long bcall_count; 411 }; 412 413 /* 414 * RPCRDMA transport -- encapsulates the structures above for 415 * integration with RPC. 416 * 417 * The contained structures are embedded, not pointers, 418 * for convenience. This structure need not be visible externally. 419 * 420 * It is allocated and initialized during mount, and released 421 * during unmount. 422 */ 423 struct rpcrdma_xprt { 424 struct rpc_xprt rx_xprt; 425 struct rpcrdma_ia rx_ia; 426 struct rpcrdma_ep rx_ep; 427 struct rpcrdma_buffer rx_buf; 428 struct delayed_work rx_connect_worker; 429 struct rpc_timeout rx_timeout; 430 struct rpcrdma_stats rx_stats; 431 }; 432 433 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt) 434 435 static inline const char * 436 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt) 437 { 438 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR]; 439 } 440 441 static inline const char * 442 rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt) 443 { 444 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT]; 445 } 446 447 /* Setting this to 0 ensures interoperability with early servers. 448 * Setting this to 1 enhances certain unaligned read/write performance. 449 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */ 450 extern int xprt_rdma_pad_optimize; 451 452 /* This setting controls the hunt for a supported memory 453 * registration strategy. 454 */ 455 extern unsigned int xprt_rdma_memreg_strategy; 456 457 /* 458 * Interface Adapter calls - xprtrdma/verbs.c 459 */ 460 int rpcrdma_ia_open(struct rpcrdma_xprt *xprt); 461 void rpcrdma_ia_remove(struct rpcrdma_ia *ia); 462 void rpcrdma_ia_close(struct rpcrdma_ia *); 463 464 /* 465 * Endpoint calls - xprtrdma/verbs.c 466 */ 467 int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt); 468 void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt); 469 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *); 470 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *); 471 472 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *, 473 struct rpcrdma_req *); 474 void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp); 475 476 /* 477 * Buffer calls - xprtrdma/verbs.c 478 */ 479 struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size, 480 gfp_t flags); 481 int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 482 void rpcrdma_req_destroy(struct rpcrdma_req *req); 483 int rpcrdma_buffer_create(struct rpcrdma_xprt *); 484 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *); 485 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt); 486 487 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt); 488 void rpcrdma_mr_put(struct rpcrdma_mr *mr); 489 void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt); 490 491 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); 492 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, 493 struct rpcrdma_req *req); 494 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *); 495 496 bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, 497 gfp_t flags); 498 bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, 499 struct rpcrdma_regbuf *rb); 500 501 /** 502 * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped 503 * 504 * Returns true if the buffer is now mapped to rb->rg_device. 505 */ 506 static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb) 507 { 508 return rb->rg_device != NULL; 509 } 510 511 /** 512 * rpcrdma_regbuf_dma_map - DMA-map a regbuf 513 * @r_xprt: controlling transport instance 514 * @rb: regbuf to be mapped 515 * 516 * Returns true if the buffer is currently DMA mapped. 517 */ 518 static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, 519 struct rpcrdma_regbuf *rb) 520 { 521 if (likely(rpcrdma_regbuf_is_mapped(rb))) 522 return true; 523 return __rpcrdma_regbuf_dma_map(r_xprt, rb); 524 } 525 526 /* 527 * Wrappers for chunk registration, shared by read/write chunk code. 528 */ 529 530 static inline enum dma_data_direction 531 rpcrdma_data_dir(bool writing) 532 { 533 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 534 } 535 536 /* Memory registration calls xprtrdma/frwr_ops.c 537 */ 538 void frwr_reset(struct rpcrdma_req *req); 539 int frwr_query_device(struct rpcrdma_xprt *r_xprt, 540 const struct ib_device *device); 541 int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr); 542 void frwr_release_mr(struct rpcrdma_mr *mr); 543 struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, 544 struct rpcrdma_mr_seg *seg, 545 int nsegs, bool writing, __be32 xid, 546 struct rpcrdma_mr *mr); 547 int frwr_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req); 548 void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs); 549 void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 550 void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 551 552 /* 553 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c 554 */ 555 556 enum rpcrdma_chunktype { 557 rpcrdma_noch = 0, 558 rpcrdma_noch_pullup, 559 rpcrdma_noch_mapped, 560 rpcrdma_readch, 561 rpcrdma_areadch, 562 rpcrdma_writech, 563 rpcrdma_replych 564 }; 565 566 int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt, 567 struct rpcrdma_req *req, u32 hdrlen, 568 struct xdr_buf *xdr, 569 enum rpcrdma_chunktype rtype); 570 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc); 571 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst); 572 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *); 573 void rpcrdma_reset_cwnd(struct rpcrdma_xprt *r_xprt); 574 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep); 575 void rpcrdma_reply_handler(struct rpcrdma_rep *rep); 576 577 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len) 578 { 579 xdr->head[0].iov_len = len; 580 xdr->len = len; 581 } 582 583 /* RPC/RDMA module init - xprtrdma/transport.c 584 */ 585 extern unsigned int xprt_rdma_max_inline_read; 586 extern unsigned int xprt_rdma_max_inline_write; 587 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap); 588 void xprt_rdma_free_addresses(struct rpc_xprt *xprt); 589 void xprt_rdma_close(struct rpc_xprt *xprt); 590 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq); 591 int xprt_rdma_init(void); 592 void xprt_rdma_cleanup(void); 593 594 /* Backchannel calls - xprtrdma/backchannel.c 595 */ 596 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 597 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int); 598 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *); 599 unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *); 600 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); 601 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *); 602 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst); 603 void xprt_rdma_bc_free_rqst(struct rpc_rqst *); 604 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); 605 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 606 607 extern struct xprt_class xprt_rdma_bc; 608 609 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */ 610