root/net/sunrpc/xprtrdma/xprt_rdma.h

INCLUDED FROM

DEFINITIONS

1. rdmab_addr
2. rdmab_length
3. rdmab_lkey
4. rdmab_device
5. rdmab_data
6. rpcr_to_rdmar
7. rpcrdma_mr_push
8. rpcrdma_mr_pop
9. rpcrdma_addrstr
10. rpcrdma_portstr
11. rpcrdma_mr_recycle
12. rpcrdma_regbuf_is_mapped
13. rpcrdma_regbuf_dma_map
14. rpcrdma_data_dir
15. rpcrdma_set_xdrlen

   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         struct list_head        rr_all;
 207 };
 208 
 209 /* To reduce the rate at which a transport invokes ib_post_recv
 210  * (and thus the hardware doorbell rate), xprtrdma posts Receive
 211  * WRs in batches.
 212  *
 213  * Setting this to zero disables Receive post batching.
 214  */
 215 enum {
 216         RPCRDMA_MAX_RECV_BATCH = 7,
 217 };
 218 
 219 /* struct rpcrdma_sendctx - DMA mapped SGEs to unmap after Send completes
 220  */
 221 struct rpcrdma_req;
 222 struct rpcrdma_xprt;
 223 struct rpcrdma_sendctx {
 224         struct ib_send_wr       sc_wr;
 225         struct ib_cqe           sc_cqe;
 226         struct ib_device        *sc_device;
 227         struct rpcrdma_xprt     *sc_xprt;
 228         struct rpcrdma_req      *sc_req;
 229         unsigned int            sc_unmap_count;
 230         struct ib_sge           sc_sges[];
 231 };
 232 
 233 /*
 234  * struct rpcrdma_mr - external memory region metadata
 235  *
 236  * An external memory region is any buffer or page that is registered
 237  * on the fly (ie, not pre-registered).
 238  */
 239 struct rpcrdma_frwr {
 240         struct ib_mr                    *fr_mr;
 241         struct ib_cqe                   fr_cqe;
 242         struct completion               fr_linv_done;
 243         union {
 244                 struct ib_reg_wr        fr_regwr;
 245                 struct ib_send_wr       fr_invwr;
 246         };
 247 };
 248 
 249 struct rpcrdma_req;
 250 struct rpcrdma_mr {
 251         struct list_head        mr_list;
 252         struct rpcrdma_req      *mr_req;
 253         struct scatterlist      *mr_sg;
 254         int                     mr_nents;
 255         enum dma_data_direction mr_dir;
 256         struct rpcrdma_frwr     frwr;
 257         struct rpcrdma_xprt     *mr_xprt;
 258         u32                     mr_handle;
 259         u32                     mr_length;
 260         u64                     mr_offset;
 261         struct work_struct      mr_recycle;
 262         struct list_head        mr_all;
 263 };
 264 
 265 /*
 266  * struct rpcrdma_req -- structure central to the request/reply sequence.
 267  *
 268  * N of these are associated with a transport instance, and stored in
 269  * struct rpcrdma_buffer. N is the max number of outstanding requests.
 270  *
 271  * It includes pre-registered buffer memory for send AND recv.
 272  * The recv buffer, however, is not owned by this structure, and
 273  * is "donated" to the hardware when a recv is posted. When a
 274  * reply is handled, the recv buffer used is given back to the
 275  * struct rpcrdma_req associated with the request.
 276  *
 277  * In addition to the basic memory, this structure includes an array
 278  * of iovs for send operations. The reason is that the iovs passed to
 279  * ib_post_{send,recv} must not be modified until the work request
 280  * completes.
 281  */
 282 
 283 /* Maximum number of page-sized "segments" per chunk list to be
 284  * registered or invalidated. Must handle a Reply chunk:
 285  */
 286 enum {
 287         RPCRDMA_MAX_IOV_SEGS    = 3,
 288         RPCRDMA_MAX_DATA_SEGS   = ((1 * 1024 * 1024) / PAGE_SIZE) + 1,
 289         RPCRDMA_MAX_SEGS        = RPCRDMA_MAX_DATA_SEGS +
 290                                   RPCRDMA_MAX_IOV_SEGS,
 291 };
 292 
 293 struct rpcrdma_mr_seg {         /* chunk descriptors */
 294         u32             mr_len;         /* length of chunk or segment */
 295         struct page     *mr_page;       /* owning page, if any */
 296         char            *mr_offset;     /* kva if no page, else offset */
 297 };
 298 
 299 /* The Send SGE array is provisioned to send a maximum size
 300  * inline request:
 301  * - RPC-over-RDMA header
 302  * - xdr_buf head iovec
 303  * - RPCRDMA_MAX_INLINE bytes, in pages
 304  * - xdr_buf tail iovec
 305  *
 306  * The actual number of array elements consumed by each RPC
 307  * depends on the device's max_sge limit.
 308  */
 309 enum {
 310         RPCRDMA_MIN_SEND_SGES = 3,
 311         RPCRDMA_MAX_PAGE_SGES = RPCRDMA_MAX_INLINE >> PAGE_SHIFT,
 312         RPCRDMA_MAX_SEND_SGES = 1 + 1 + RPCRDMA_MAX_PAGE_SGES + 1,
 313 };
 314 
 315 struct rpcrdma_buffer;
 316 struct rpcrdma_req {
 317         struct list_head        rl_list;
 318         struct rpc_rqst         rl_slot;
 319         struct rpcrdma_rep      *rl_reply;
 320         struct xdr_stream       rl_stream;
 321         struct xdr_buf          rl_hdrbuf;
 322         struct rpcrdma_sendctx  *rl_sendctx;
 323         struct rpcrdma_regbuf   *rl_rdmabuf;    /* xprt header */
 324         struct rpcrdma_regbuf   *rl_sendbuf;    /* rq_snd_buf */
 325         struct rpcrdma_regbuf   *rl_recvbuf;    /* rq_rcv_buf */
 326 
 327         struct list_head        rl_all;
 328         struct kref             rl_kref;
 329 
 330         struct list_head        rl_free_mrs;
 331         struct list_head        rl_registered;
 332         struct rpcrdma_mr_seg   rl_segments[RPCRDMA_MAX_SEGS];
 333 };
 334 
 335 static inline struct rpcrdma_req *
 336 rpcr_to_rdmar(const struct rpc_rqst *rqst)
 337 {
 338         return container_of(rqst, struct rpcrdma_req, rl_slot);
 339 }
 340 
 341 static inline void
 342 rpcrdma_mr_push(struct rpcrdma_mr *mr, struct list_head *list)
 343 {
 344         list_add(&mr->mr_list, list);
 345 }
 346 
 347 static inline struct rpcrdma_mr *
 348 rpcrdma_mr_pop(struct list_head *list)
 349 {
 350         struct rpcrdma_mr *mr;
 351 
 352         mr = list_first_entry_or_null(list, struct rpcrdma_mr, mr_list);
 353         if (mr)
 354                 list_del_init(&mr->mr_list);
 355         return mr;
 356 }
 357 
 358 /*
 359  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for
 360  * inline requests/replies, and client/server credits.
 361  *
 362  * One of these is associated with a transport instance
 363  */
 364 struct rpcrdma_buffer {
 365         spinlock_t              rb_lock;
 366         struct list_head        rb_send_bufs;
 367         struct list_head        rb_mrs;
 368 
 369         unsigned long           rb_sc_head;
 370         unsigned long           rb_sc_tail;
 371         unsigned long           rb_sc_last;
 372         struct rpcrdma_sendctx  **rb_sc_ctxs;
 373 
 374         struct list_head        rb_allreqs;
 375         struct list_head        rb_all_mrs;
 376         struct list_head        rb_all_reps;
 377 
 378         struct llist_head       rb_free_reps;
 379 
 380         u32                     rb_max_requests;
 381         u32                     rb_credits;     /* most recent credit grant */
 382 
 383         u32                     rb_bc_srv_max_requests;
 384         u32                     rb_bc_max_requests;
 385 
 386         struct work_struct      rb_refresh_worker;
 387 };
 388 
 389 /*
 390  * Statistics for RPCRDMA
 391  */
 392 struct rpcrdma_stats {
 393         /* accessed when sending a call */
 394         unsigned long           read_chunk_count;
 395         unsigned long           write_chunk_count;
 396         unsigned long           reply_chunk_count;
 397         unsigned long long      total_rdma_request;
 398 
 399         /* rarely accessed error counters */
 400         unsigned long long      pullup_copy_count;
 401         unsigned long           hardway_register_count;
 402         unsigned long           failed_marshal_count;
 403         unsigned long           bad_reply_count;
 404         unsigned long           mrs_recycled;
 405         unsigned long           mrs_orphaned;
 406         unsigned long           mrs_allocated;
 407         unsigned long           empty_sendctx_q;
 408 
 409         /* accessed when receiving a reply */
 410         unsigned long long      total_rdma_reply;
 411         unsigned long long      fixup_copy_count;
 412         unsigned long           reply_waits_for_send;
 413         unsigned long           local_inv_needed;
 414         unsigned long           nomsg_call_count;
 415         unsigned long           bcall_count;
 416 };
 417 
 418 /*
 419  * RPCRDMA transport -- encapsulates the structures above for
 420  * integration with RPC.
 421  *
 422  * The contained structures are embedded, not pointers,
 423  * for convenience. This structure need not be visible externally.
 424  *
 425  * It is allocated and initialized during mount, and released
 426  * during unmount.
 427  */
 428 struct rpcrdma_xprt {
 429         struct rpc_xprt         rx_xprt;
 430         struct rpcrdma_ia       rx_ia;
 431         struct rpcrdma_ep       rx_ep;
 432         struct rpcrdma_buffer   rx_buf;
 433         struct delayed_work     rx_connect_worker;
 434         struct rpc_timeout      rx_timeout;
 435         struct rpcrdma_stats    rx_stats;
 436 };
 437 
 438 #define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, rx_xprt)
 439 
 440 static inline const char *
 441 rpcrdma_addrstr(const struct rpcrdma_xprt *r_xprt)
 442 {
 443         return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_ADDR];
 444 }
 445 
 446 static inline const char *
 447 rpcrdma_portstr(const struct rpcrdma_xprt *r_xprt)
 448 {
 449         return r_xprt->rx_xprt.address_strings[RPC_DISPLAY_PORT];
 450 }
 451 
 452 /* Setting this to 0 ensures interoperability with early servers.
 453  * Setting this to 1 enhances certain unaligned read/write performance.
 454  * Default is 0, see sysctl entry and rpc_rdma.c rpcrdma_convert_iovs() */
 455 extern int xprt_rdma_pad_optimize;
 456 
 457 /* This setting controls the hunt for a supported memory
 458  * registration strategy.
 459  */
 460 extern unsigned int xprt_rdma_memreg_strategy;
 461 
 462 /*
 463  * Interface Adapter calls - xprtrdma/verbs.c
 464  */
 465 int rpcrdma_ia_open(struct rpcrdma_xprt *xprt);
 466 void rpcrdma_ia_remove(struct rpcrdma_ia *ia);
 467 void rpcrdma_ia_close(struct rpcrdma_ia *);
 468 
 469 /*
 470  * Endpoint calls - xprtrdma/verbs.c
 471  */
 472 int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt);
 473 void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt);
 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 void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
 480 
 481 /*
 482  * Buffer calls - xprtrdma/verbs.c
 483  */
 484 struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
 485                                        gfp_t flags);
 486 void rpcrdma_req_destroy(struct rpcrdma_req *req);
 487 int rpcrdma_buffer_create(struct rpcrdma_xprt *);
 488 void rpcrdma_buffer_destroy(struct rpcrdma_buffer *);
 489 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt);
 490 
 491 struct rpcrdma_mr *rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt);
 492 void rpcrdma_mr_put(struct rpcrdma_mr *mr);
 493 
 494 static inline void
 495 rpcrdma_mr_recycle(struct rpcrdma_mr *mr)
 496 {
 497         schedule_work(&mr->mr_recycle);
 498 }
 499 
 500 struct rpcrdma_req *rpcrdma_buffer_get(struct rpcrdma_buffer *);
 501 void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers,
 502                         struct rpcrdma_req *req);
 503 void rpcrdma_recv_buffer_put(struct rpcrdma_rep *);
 504 
 505 bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size,
 506                             gfp_t flags);
 507 bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
 508                               struct rpcrdma_regbuf *rb);
 509 
 510 /**
 511  * rpcrdma_regbuf_is_mapped - check if buffer is DMA mapped
 512  *
 513  * Returns true if the buffer is now mapped to rb->rg_device.
 514  */
 515 static inline bool rpcrdma_regbuf_is_mapped(struct rpcrdma_regbuf *rb)
 516 {
 517         return rb->rg_device != NULL;
 518 }
 519 
 520 /**
 521  * rpcrdma_regbuf_dma_map - DMA-map a regbuf
 522  * @r_xprt: controlling transport instance
 523  * @rb: regbuf to be mapped
 524  *
 525  * Returns true if the buffer is currently DMA mapped.
 526  */
 527 static inline bool rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
 528                                           struct rpcrdma_regbuf *rb)
 529 {
 530         if (likely(rpcrdma_regbuf_is_mapped(rb)))
 531                 return true;
 532         return __rpcrdma_regbuf_dma_map(r_xprt, rb);
 533 }
 534 
 535 /*
 536  * Wrappers for chunk registration, shared by read/write chunk code.
 537  */
 538 
 539 static inline enum dma_data_direction
 540 rpcrdma_data_dir(bool writing)
 541 {
 542         return writing ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 543 }
 544 
 545 /* Memory registration calls xprtrdma/frwr_ops.c
 546  */
 547 bool frwr_is_supported(struct ib_device *device);
 548 void frwr_recycle(struct rpcrdma_req *req);
 549 void frwr_reset(struct rpcrdma_req *req);
 550 int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep);
 551 int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr);
 552 void frwr_release_mr(struct rpcrdma_mr *mr);
 553 size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt);
 554 struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
 555                                 struct rpcrdma_mr_seg *seg,
 556                                 int nsegs, bool writing, __be32 xid,
 557                                 struct rpcrdma_mr *mr);
 558 int frwr_send(struct rpcrdma_ia *ia, struct rpcrdma_req *req);
 559 void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs);
 560 void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
 561 void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req);
 562 
 563 /*
 564  * RPC/RDMA protocol calls - xprtrdma/rpc_rdma.c
 565  */
 566 
 567 enum rpcrdma_chunktype {
 568         rpcrdma_noch = 0,
 569         rpcrdma_readch,
 570         rpcrdma_areadch,
 571         rpcrdma_writech,
 572         rpcrdma_replych
 573 };
 574 
 575 int rpcrdma_prepare_send_sges(struct rpcrdma_xprt *r_xprt,
 576                               struct rpcrdma_req *req, u32 hdrlen,
 577                               struct xdr_buf *xdr,
 578                               enum rpcrdma_chunktype rtype);
 579 void rpcrdma_sendctx_unmap(struct rpcrdma_sendctx *sc);
 580 int rpcrdma_marshal_req(struct rpcrdma_xprt *r_xprt, struct rpc_rqst *rqst);
 581 void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *);
 582 void rpcrdma_complete_rqst(struct rpcrdma_rep *rep);
 583 void rpcrdma_reply_handler(struct rpcrdma_rep *rep);
 584 
 585 static inline void rpcrdma_set_xdrlen(struct xdr_buf *xdr, size_t len)
 586 {
 587         xdr->head[0].iov_len = len;
 588         xdr->len = len;
 589 }
 590 
 591 /* RPC/RDMA module init - xprtrdma/transport.c
 592  */
 593 extern unsigned int xprt_rdma_slot_table_entries;
 594 extern unsigned int xprt_rdma_max_inline_read;
 595 extern unsigned int xprt_rdma_max_inline_write;
 596 void xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap);
 597 void xprt_rdma_free_addresses(struct rpc_xprt *xprt);
 598 void xprt_rdma_close(struct rpc_xprt *xprt);
 599 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq);
 600 int xprt_rdma_init(void);
 601 void xprt_rdma_cleanup(void);
 602 
 603 /* Backchannel calls - xprtrdma/backchannel.c
 604  */
 605 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 606 int xprt_rdma_bc_setup(struct rpc_xprt *, unsigned int);
 607 size_t xprt_rdma_bc_maxpayload(struct rpc_xprt *);
 608 unsigned int xprt_rdma_bc_max_slots(struct rpc_xprt *);
 609 int rpcrdma_bc_post_recv(struct rpcrdma_xprt *, unsigned int);
 610 void rpcrdma_bc_receive_call(struct rpcrdma_xprt *, struct rpcrdma_rep *);
 611 int xprt_rdma_bc_send_reply(struct rpc_rqst *rqst);
 612 void xprt_rdma_bc_free_rqst(struct rpc_rqst *);
 613 void xprt_rdma_bc_destroy(struct rpc_xprt *, unsigned int);
 614 #endif  /* CONFIG_SUNRPC_BACKCHANNEL */
 615 
 616 extern struct xprt_class xprt_rdma_bc;
 617 
 618 #endif                          /* _LINUX_SUNRPC_XPRT_RDMA_H */