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_segs; 75 unsigned int ri_max_frwr_depth; 76 unsigned int ri_max_send_sges; 77 bool ri_implicit_roundup; 78 enum ib_mr_type ri_mrtype; 79 unsigned long ri_flags; 80 struct completion ri_done; 81 struct completion ri_remove_done; 82 }; 83 84 enum { 85 RPCRDMA_IAF_REMOVING = 0, 86 }; 87 88 /* 89 * RDMA Endpoint -- one per transport instance 90 */ 91 92 struct rpcrdma_ep { 93 unsigned int rep_send_count; 94 unsigned int rep_send_batch; 95 unsigned int rep_max_inline_send; 96 unsigned int rep_max_inline_recv; 97 int rep_connected; 98 struct ib_qp_init_attr rep_attr; 99 wait_queue_head_t rep_connect_wait; 100 struct rpcrdma_connect_private rep_cm_private; 101 struct rdma_conn_param rep_remote_cma; 102 unsigned int rep_max_requests; /* set by /proc */ 103 unsigned int rep_inline_send; /* negotiated */ 104 unsigned int rep_inline_recv; /* negotiated */ 105 int rep_receive_count; 106 }; 107 108 /* Pre-allocate extra Work Requests for handling backward receives 109 * and sends. This is a fixed value because the Work Queues are 110 * allocated when the forward channel is set up, long before the 111 * backchannel is provisioned. This value is two times 112 * NFS4_DEF_CB_SLOT_TABLE_SIZE. 113 */ 114 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 115 #define RPCRDMA_BACKWARD_WRS (32) 116 #else 117 #define RPCRDMA_BACKWARD_WRS (0) 118 #endif 119 120 /* Registered buffer -- registered kmalloc'd memory for RDMA SEND/RECV 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 void *rg_data; 128 }; 129 130 static inline u64 rdmab_addr(struct rpcrdma_regbuf *rb) 131 { 132 return rb->rg_iov.addr; 133 } 134 135 static inline u32 rdmab_length(struct rpcrdma_regbuf *rb) 136 { 137 return rb->rg_iov.length; 138 } 139 140 static inline u32 rdmab_lkey(struct rpcrdma_regbuf *rb) 141 { 142 return rb->rg_iov.lkey; 143 } 144 145 static inline struct ib_device *rdmab_device(struct rpcrdma_regbuf *rb) 146 { 147 return rb->rg_device; 148 } 149 150 static inline void *rdmab_data(const struct rpcrdma_regbuf *rb) 151 { 152 return rb->rg_data; 153 } 154 155 #define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN) 156 157 /* To ensure a transport can always make forward progress, 158 * the number of RDMA segments allowed in header chunk lists 159 * is capped at 16. This prevents less-capable devices from 160 * overrunning the Send buffer while building chunk lists. 161 * 162 * Elements of the Read list take up more room than the 163 * Write list or Reply chunk. 16 read segments means the 164 * chunk lists cannot consume more than 165 * 166 * ((16 + 2) * read segment size) + 1 XDR words, 167 * 168 * or about 400 bytes. The fixed part of the header is 169 * another 24 bytes. Thus when the inline threshold is 170 * 1024 bytes, at least 600 bytes are available for RPC 171 * message bodies. 172 */ 173 enum { 174 RPCRDMA_MAX_HDR_SEGS = 16, 175 }; 176 177 /* 178 * struct rpcrdma_rep -- this structure encapsulates state required 179 * to receive and complete an RPC Reply, asychronously. It needs 180 * several pieces of state: 181 * 182 * o receive buffer and ib_sge (donated to provider) 183 * o status of receive (success or not, length, inv rkey) 184 * o bookkeeping state to get run by reply handler (XDR stream) 185 * 186 * These structures are allocated during transport initialization. 187 * N of these are associated with a transport instance, managed by 188 * struct rpcrdma_buffer. N is the max number of outstanding RPCs. 189 */ 190 191 struct rpcrdma_rep { 192 struct ib_cqe rr_cqe; 193 __be32 rr_xid; 194 __be32 rr_vers; 195 __be32 rr_proc; 196 int rr_wc_flags; 197 u32 rr_inv_rkey; 198 bool rr_temp; 199 struct rpcrdma_regbuf *rr_rdmabuf; 200 struct rpcrdma_xprt *rr_rxprt; 201 struct rpc_rqst *rr_rqst; 202 struct xdr_buf rr_hdrbuf; 203 struct xdr_stream rr_stream; 204 struct llist_node rr_node; 205 struct ib_recv_wr rr_recv_wr; 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_xprt; 222 struct rpcrdma_sendctx { 223 struct ib_send_wr sc_wr; 224 struct ib_cqe sc_cqe; 225 struct ib_device *sc_device; 226 struct rpcrdma_xprt *sc_xprt; 227 struct rpcrdma_req *sc_req; 228 unsigned int sc_unmap_count; 229 struct ib_sge sc_sges[]; 230 }; 231 232 /* 233 * struct rpcrdma_mr - external memory region metadata 234 * 235 * An external memory region is any buffer or page that is registered 236 * on the fly (ie, not pre-registered). 237 */ 238 struct rpcrdma_frwr { 239 struct ib_mr *fr_mr; 240 struct ib_cqe fr_cqe; 241 struct completion fr_linv_done; 242 union { 243 struct ib_reg_wr fr_regwr; 244 struct ib_send_wr fr_invwr; 245 }; 246 }; 247 248 struct rpcrdma_req; 249 struct rpcrdma_mr { 250 struct list_head mr_list; 251 struct rpcrdma_req *mr_req; 252 struct scatterlist *mr_sg; 253 int mr_nents; 254 enum dma_data_direction mr_dir; 255 struct rpcrdma_frwr frwr; 256 struct rpcrdma_xprt *mr_xprt; 257 u32 mr_handle; 258 u32 mr_length; 259 u64 mr_offset; 260 struct work_struct mr_recycle; 261 struct list_head mr_all; 262 }; 263 264 /* 265 * struct rpcrdma_req -- structure central to the request/reply sequence. 266 * 267 * N of these are associated with a transport instance, and stored in 268 * struct rpcrdma_buffer. N is the max number of outstanding requests. 269 * 270 * It includes pre-registered buffer memory for send AND recv. 271 * The recv buffer, however, is not owned by this structure, and 272 * is "donated" to the hardware when a recv is posted. When a 273 * reply is handled, the recv buffer used is given back to the 274 * struct rpcrdma_req associated with the request. 275 * 276 * In addition to the basic memory, this structure includes an array 277 * of iovs for send operations. The reason is that the iovs passed to 278 * ib_post_{send,recv} must not be modified until the work request 279 * completes. 280 */ 281 282 /* Maximum number of page-sized "segments" per chunk list to be 283 * registered or invalidated. Must handle a Reply chunk: 284 */ 285 enum { 286 RPCRDMA_MAX_IOV_SEGS = 3, 287 RPCRDMA_MAX_DATA_SEGS = ((1 * 1024 * 1024) / PAGE_SIZE) + 1, 288 RPCRDMA_MAX_SEGS = RPCRDMA_MAX_DATA_SEGS + 289 RPCRDMA_MAX_IOV_SEGS, 290 }; 291 292 struct rpcrdma_mr_seg { /* chunk descriptors */ 293 u32 mr_len; /* length of chunk or segment */ 294 struct page *mr_page; /* owning page, if any */ 295 char *mr_offset; /* kva if no page, else offset */ 296 }; 297 298 /* The Send SGE array is provisioned to send a maximum size 299 * inline request: 300 * - RPC-over-RDMA header 301 * - xdr_buf head iovec 302 * - RPCRDMA_MAX_INLINE bytes, in pages 303 * - xdr_buf tail iovec 304 * 305 * The actual number of array elements consumed by each RPC 306 * depends on the device's max_sge limit. 307 */ 308 enum { 309 RPCRDMA_MIN_SEND_SGES = 3, 310 RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT, 311 RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1, 312 }; 313 314 struct rpcrdma_buffer; 315 struct rpcrdma_req { 316 struct list_head rl_list; 317 struct rpc_rqst rl_slot; 318 struct rpcrdma_rep *rl_reply; 319 struct xdr_stream rl_stream; 320 struct xdr_buf rl_hdrbuf; 321 struct rpcrdma_sendctx *rl_sendctx; 322 struct rpcrdma_regbuf *rl_rdmabuf; /* xprt header */ 323 struct rpcrdma_regbuf *rl_sendbuf; /* rq_snd_buf */ 324 struct rpcrdma_regbuf *rl_recvbuf; /* rq_rcv_buf */ 325 326 struct list_head rl_all; 327 struct kref rl_kref; 328 329 struct list_head rl_free_mrs; 330 struct list_head rl_registered; 331 struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS]; 332 }; 333 334 static inline struct rpcrdma_req * 335 rpcr_to_rdmar(const struct rpc_rqst *rqst) 336 { 337 return container_of(rqst, struct rpcrdma_req, rl_slot); 338 } 339 340 static inline void 341 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list) 342 { 343 list_add(&mr->mr_list, list); 344 } 345 346 static inline struct rpcrdma_mr * 347 rpcrdma_mr_pop(struct list_head *list) 348 { 349 struct rpcrdma_mr *mr; 350 351 mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list); 352 if (mr) 353 list_del_init(&mr->mr_list); 354 return mr; 355 } 356 357 /* 358 * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for 359 * inline requests/replies, and client/server credits. 360 * 361 * One of these is associated with a transport instance 362 */ 363 struct rpcrdma_buffer { 364 spinlock_t rb_lock; 365 struct list_head rb_send_bufs; 366 struct list_head rb_mrs; 367 368 unsigned long rb_sc_head; 369 unsigned long rb_sc_tail; 370 unsigned long rb_sc_last; 371 struct rpcrdma_sendctx **rb_sc_ctxs; 372 373 struct list_head rb_allreqs; 374 struct list_head rb_all_mrs; 375 376 struct llist_head rb_free_reps; 377 378 u32 rb_max_requests; 379 u32 rb_credits; /* most recent credit grant */ 380 381 u32 rb_bc_srv_max_requests; 382 u32 rb_bc_max_requests; 383 384 struct work_struct rb_refresh_worker; 385 }; 386 387 /* 388 * Statistics for RPCRDMA 389 */ 390 struct rpcrdma_stats { 391 /* accessed when sending a call */ 392 unsigned long read_chunk_count; 393 unsigned long write_chunk_count; 394 unsigned long reply_chunk_count; 395 unsigned long long total_rdma_request; 396 397 /* rarely accessed error counters */ 398 unsigned long long pullup_copy_count; 399 unsigned long hardway_register_count; 400 unsigned long failed_marshal_count; 401 unsigned long bad_reply_count; 402 unsigned long mrs_recycled; 403 unsigned long mrs_orphaned; 404 unsigned long mrs_allocated; 405 unsigned long empty_sendctx_q; 406 407 /* accessed when receiving a reply */ 408 unsigned long long total_rdma_reply; 409 unsigned long long fixup_copy_count; 410 unsigned long reply_waits_for_send; 411 unsigned long local_inv_needed; 412 unsigned long nomsg_call_count; 413 unsigned long bcall_count; 414 }; 415 416 /* 417 * RPCRDMA transport -- encapsulates the structures above for 418 * integration with RPC. 419 * 420 * The contained structures are embedded, not pointers, 421 * for convenience. This structure need not be visible externally. 422 * 423 * It is allocated and initialized during mount, and released 424 * during unmount. 425 */ 426 struct rpcrdma_xprt { 427 struct rpc_xprt rx_xprt; 428 struct rpcrdma_ia rx_ia; 429 struct rpcrdma_ep rx_ep; 430 struct rpcrdma_buffer rx_buf; 431 struct delayed_work rx_connect_worker; 432 struct rpc_timeout rx_timeout; 433 struct rpcrdma_stats rx_stats; 434 }; 435 436 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt) 437 438 static inline const char * 439 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt) 440 { 441 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR]; 442 } 443 444 static inline const char * 445 rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt) 446 { 447 return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT]; 448 } 449 450 /* Setting this to 0 ensures interoperability with early servers. 451 * Setting this to 1 enhances certain unaligned read/write performance. 452 * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */ 453 extern int xprt_rdma_pad_optimize; 454 455 /* This setting controls the hunt for a supported memory 456 * registration strategy. 457 */ 458 extern unsigned int xprt_rdma_memreg_strategy; 459 460 /* 461 * Interface Adapter calls - xprtrdma/verbs.c 462 */ 463 int rpcrdma_ia_open(struct rpcrdma_xprt *xprt); 464 void rpcrdma_ia_remove(struct rpcrdma_ia *ia); 465 void rpcrdma_ia_close(struct rpcrdma_ia *); 466 467 /* 468 * Endpoint calls - xprtrdma/verbs.c 469 */ 470 int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt); 471 void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt); 472 int rpcrdma_ep_connect(struct rpcrdma_ep *, struct rpcrdma_ia *); 473 void rpcrdma_ep_disconnect(struct rpcrdma_ep *, struct rpcrdma_ia *); 474 475 int rpcrdma_ep_post(struct rpcrdma_ia *, struct rpcrdma_ep *, 476 struct rpcrdma_req *); 477 478 /* 479 * Buffer calls - xprtrdma/verbs.c 480 */ 481 struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size, 482 gfp_t flags); 483 void rpcrdma_req_destroy(struct rpcrdma_req *req); 484 int rpcrdma_buffer_create(struct rpcrdma_xprt *); 485 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *); 486 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt); 487 488 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt); 489 void rpcrdma_mr_put(struct rpcrdma_mr *mr); 490 491 static inline void 492 rpcrdma_mr_recycle(struct rpcrdma_mr *mr) 493 { 494 schedule_work(&mr->mr_recycle); 495 } 496 497 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *); 498 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, 499 struct rpcrdma_req *req); 500 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *); 501 502 bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, 503 gfp_t flags); 504 bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, 505 struct rpcrdma_regbuf *rb); 506 507 /** 508 * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped 509 * 510 * Returns true if the buffer is now mapped to rb->rg_device. 511 */ 512 static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb) 513 { 514 return rb->rg_device != NULL; 515 } 516 517 /** 518 * rpcrdma_regbuf_dma_map - DMA-map a regbuf 519 * @r_xprt: controlling transport instance 520 * @rb: regbuf to be mapped 521 * 522 * Returns true if the buffer is currently DMA mapped. 523 */ 524 static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt, 525 struct rpcrdma_regbuf *rb) 526 { 527 if (likely(rpcrdma_regbuf_is_mapped(rb))) 528 return true; 529 return __rpcrdma_regbuf_dma_map(r_xprt, rb); 530 } 531 532 /* 533 * Wrappers for chunk registration, shared by read/write chunk code. 534 */ 535 536 static inline enum dma_data_direction 537 rpcrdma_data_dir(bool writing) 538 { 539 return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE; 540 } 541 542 /* Memory registration calls xprtrdma/frwr_ops.c 543 */ 544 bool frwr_is_supported(struct ib_device *device); 545 void frwr_recycle(struct rpcrdma_req *req); 546 void frwr_reset(struct rpcrdma_req *req); 547 int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep); 548 int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr); 549 void frwr_release_mr(struct rpcrdma_mr *mr); 550 size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt); 551 struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, 552 struct rpcrdma_mr_seg *seg, 553 int nsegs, bool writing, __be32 xid, 554 struct rpcrdma_mr *mr); 555 int frwr_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req); 556 void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs); 557 void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 558 void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req); 559 560 /* 561 * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c 562 */ 563 564 enum rpcrdma_chunktype { 565 rpcrdma_noch = 0, 566 rpcrdma_readch, 567 rpcrdma_areadch, 568 rpcrdma_writech, 569 rpcrdma_replych 570 }; 571 572 int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt, 573 struct rpcrdma_req *req, u32 hdrlen, 574 struct xdr_buf *xdr, 575 enum rpcrdma_chunktype rtype); 576 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc); 577 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst); 578 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *); 579 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep); 580 void rpcrdma_reply_handler(struct rpcrdma_rep *rep); 581 582 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len) 583 { 584 xdr->head[0].iov_len = len; 585 xdr->len = len; 586 } 587 588 /* RPC/RDMA module init - xprtrdma/transport.c 589 */ 590 extern unsigned int xprt_rdma_slot_table_entries; 591 extern unsigned int xprt_rdma_max_inline_read; 592 extern unsigned int xprt_rdma_max_inline_write; 593 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap); 594 void xprt_rdma_free_addresses(struct rpc_xprt *xprt); 595 void xprt_rdma_close(struct rpc_xprt *xprt); 596 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq); 597 int xprt_rdma_init(void); 598 void xprt_rdma_cleanup(void); 599 600 /* Backchannel calls - xprtrdma/backchannel.c 601 */ 602 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 603 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int); 604 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *); 605 unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *); 606 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int); 607 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *); 608 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst); 609 void xprt_rdma_bc_free_rqst(struct rpc_rqst *); 610 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int); 611 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 612 613 extern struct xprt_class xprt_rdma_bc; 614 615 #endif /* _LINUX_SUNRPC_XPRT_RDMA_H */ 616