net/9p/trans_rdma.c

   1 /*
   2  * linux/fs/9p/trans_rdma.c
   3  *
   4  * RDMA transport layer based on the trans_fd.c implementation.
   5  *
   6  *  Copyright (C) 2008 by Tom Tucker <[email protected]>
   7  *  Copyright (C) 2006 by Russ Cox <[email protected]>
   8  *  Copyright (C) 2004-2005 by Latchesar Ionkov <[email protected]>
   9  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <[email protected]>
  10  *  Copyright (C) 1997-2002 by Ron Minnich <[email protected]>
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License version 2
  14  *  as published by the Free Software Foundation.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to:
  23  *  Free Software Foundation
  24  *  51 Franklin Street, Fifth Floor
  25  *  Boston, MA  02111-1301  USA
  26  *
  27  */
  28
  29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  30
  31 #include <linux/in.h>
  32 #include <linux/module.h>
  33 #include <linux/net.h>
  34 #include <linux/ipv6.h>
  35 #include <linux/kthread.h>
  36 #include <linux/errno.h>
  37 #include <linux/kernel.h>
  38 #include <linux/un.h>
  39 #include <linux/uaccess.h>
  40 #include <linux/inet.h>
  41 #include <linux/idr.h>
  42 #include <linux/file.h>
  43 #include <linux/parser.h>
  44 #include <linux/semaphore.h>
  45 #include <linux/slab.h>
  46 #include <linux/seq_file.h>
  47 #include <net/9p/9p.h>
  48 #include <net/9p/client.h>
  49 #include <net/9p/transport.h>
  50 #include <rdma/ib_verbs.h>
  51 #include <rdma/rdma_cm.h>
  52
  53 #define P9_PORT                 5640
  54 #define P9_RDMA_SQ_DEPTH        32
  55 #define P9_RDMA_RQ_DEPTH        32
  56 #define P9_RDMA_SEND_SGE        4
  57 #define P9_RDMA_RECV_SGE        4
  58 #define P9_RDMA_IRD             0
  59 #define P9_RDMA_ORD             0
  60 #define P9_RDMA_TIMEOUT         30000           /* 30 seconds */
  61 #define P9_RDMA_MAXSIZE         (1024*1024)     /* 1MB */
  62
  63 /**
  64  * struct p9_trans_rdma - RDMA transport instance
  65  *
  66  * @state: tracks the transport state machine for connection setup and tear down
  67  * @cm_id: The RDMA CM ID
  68  * @pd: Protection Domain pointer
  69  * @qp: Queue Pair pointer
  70  * @cq: Completion Queue pointer
  71  * @dm_mr: DMA Memory Region pointer
  72  * @lkey: The local access only memory region key
  73  * @timeout: Number of uSecs to wait for connection management events
  74  * @privport: Whether a privileged port may be used
  75  * @port: The port to use
  76  * @sq_depth: The depth of the Send Queue
  77  * @sq_sem: Semaphore for the SQ
  78  * @rq_depth: The depth of the Receive Queue.
  79  * @rq_sem: Semaphore for the RQ
  80  * @excess_rc : Amount of posted Receive Contexts without a pending request.
  81  *              See rdma_request()
  82  * @addr: The remote peer's address
  83  * @req_lock: Protects the active request list
  84  * @cm_done: Completion event for connection management tracking
  85  */
  86 struct p9_trans_rdma {
  87         enum {
  88                 P9_RDMA_INIT,
  89                 P9_RDMA_ADDR_RESOLVED,
  90                 P9_RDMA_ROUTE_RESOLVED,
  91                 P9_RDMA_CONNECTED,
  92                 P9_RDMA_FLUSHING,
  93                 P9_RDMA_CLOSING,
  94                 P9_RDMA_CLOSED,
  95         } state;
  96         struct rdma_cm_id *cm_id;
  97         struct ib_pd *pd;
  98         struct ib_qp *qp;
  99         struct ib_cq *cq;
 100         long timeout;
 101         bool privport;
 102         u16 port;
 103         int sq_depth;
 104         struct semaphore sq_sem;
 105         int rq_depth;
 106         struct semaphore rq_sem;
 107         atomic_t excess_rc;
 108         struct sockaddr_in addr;
 109         spinlock_t req_lock;
 110
 111         struct completion cm_done;
 112 };
 113
 114 /**
 115  * p9_rdma_context - Keeps track of in-process WR
 116  *
 117  * @busa: Bus address to unmap when the WR completes
 118  * @req: Keeps track of requests (send)
 119  * @rc: Keepts track of replies (receive)
 120  */
 121 struct p9_rdma_req;
 122 struct p9_rdma_context {
 123         struct ib_cqe cqe;
 124         dma_addr_t busa;
 125         union {
 126                 struct p9_req_t *req;
 127                 struct p9_fcall *rc;
 128         };
 129 };
 130
 131 /**
 132  * p9_rdma_opts - Collection of mount options
 133  * @port: port of connection
 134  * @sq_depth: The requested depth of the SQ. This really doesn't need
 135  * to be any deeper than the number of threads used in the client
 136  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
 137  * @timeout: Time to wait in msecs for CM events
 138  */
 139 struct p9_rdma_opts {
 140         short port;
 141         bool privport;
 142         int sq_depth;
 143         int rq_depth;
 144         long timeout;
 145 };
 146
 147 /*
 148  * Option Parsing (code inspired by NFS code)
 149  */
 150 enum {
 151         /* Options that take integer arguments */
 152         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
 153         /* Options that take no argument */
 154         Opt_privport,
 155         Opt_err,
 156 };
 157
 158 static match_table_t tokens = {
 159         {Opt_port, "port=%u"},
 160         {Opt_sq_depth, "sq=%u"},
 161         {Opt_rq_depth, "rq=%u"},
 162         {Opt_timeout, "timeout=%u"},
 163         {Opt_privport, "privport"},
 164         {Opt_err, NULL},
 165 };
 166
 167 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
 168 {
 169         struct p9_trans_rdma *rdma = clnt->trans;
 170
 171         if (rdma->port != P9_PORT)
 172                 seq_printf(m, ",port=%u", rdma->port);
 173         if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
 174                 seq_printf(m, ",sq=%u", rdma->sq_depth);
 175         if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
 176                 seq_printf(m, ",rq=%u", rdma->rq_depth);
 177         if (rdma->timeout != P9_RDMA_TIMEOUT)
 178                 seq_printf(m, ",timeout=%lu", rdma->timeout);
 179         if (rdma->privport)
 180                 seq_puts(m, ",privport");
 181         return 0;
 182 }
 183
 184 /**
 185  * parse_opts - parse mount options into rdma options structure
 186  * @params: options string passed from mount
 187  * @opts: rdma transport-specific structure to parse options into
 188  *
 189  * Returns 0 upon success, -ERRNO upon failure
 190  */
 191 static int parse_opts(char *params, struct p9_rdma_opts *opts)
 192 {
 193         char *p;
 194         substring_t args[MAX_OPT_ARGS];
 195         int option;
 196         char *options, *tmp_options;
 197
 198         opts->port = P9_PORT;
 199         opts->sq_depth = P9_RDMA_SQ_DEPTH;
 200         opts->rq_depth = P9_RDMA_RQ_DEPTH;
 201         opts->timeout = P9_RDMA_TIMEOUT;
 202         opts->privport = false;
 203
 204         if (!params)
 205                 return 0;
 206
 207         tmp_options = kstrdup(params, GFP_KERNEL);
 208         if (!tmp_options) {
 209                 p9_debug(P9_DEBUG_ERROR,
 210                          "failed to allocate copy of option string\n");
 211                 return -ENOMEM;
 212         }
 213         options = tmp_options;
 214
 215         while ((p = strsep(&options, ",")) != NULL) {
 216                 int token;
 217                 int r;
 218                 if (!*p)
 219                         continue;
 220                 token = match_token(p, tokens, args);
 221                 if ((token != Opt_err) && (token != Opt_privport)) {
 222                         r = match_int(&args[0], &option);
 223                         if (r < 0) {
 224                                 p9_debug(P9_DEBUG_ERROR,
 225                                          "integer field, but no integer?\n");
 226                                 continue;
 227                         }
 228                 }
 229                 switch (token) {
 230                 case Opt_port:
 231                         opts->port = option;
 232                         break;
 233                 case Opt_sq_depth:
 234                         opts->sq_depth = option;
 235                         break;
 236                 case Opt_rq_depth:
 237                         opts->rq_depth = option;
 238                         break;
 239                 case Opt_timeout:
 240                         opts->timeout = option;
 241                         break;
 242                 case Opt_privport:
 243                         opts->privport = true;
 244                         break;
 245                 default:
 246                         continue;
 247                 }
 248         }
 249         /* RQ must be at least as large as the SQ */
 250         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
 251         kfree(tmp_options);
 252         return 0;
 253 }
 254
 255 static int
 256 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
 257 {
 258         struct p9_client *c = id->context;
 259         struct p9_trans_rdma *rdma = c->trans;
 260         switch (event->event) {
 261         case RDMA_CM_EVENT_ADDR_RESOLVED:
 262                 BUG_ON(rdma->state != P9_RDMA_INIT);
 263                 rdma->state = P9_RDMA_ADDR_RESOLVED;
 264                 break;
 265
 266         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 267                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
 268                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
 269                 break;
 270
 271         case RDMA_CM_EVENT_ESTABLISHED:
 272                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
 273                 rdma->state = P9_RDMA_CONNECTED;
 274                 break;
 275
 276         case RDMA_CM_EVENT_DISCONNECTED:
 277                 if (rdma)
 278                         rdma->state = P9_RDMA_CLOSED;
 279                 if (c)
 280                         c->status = Disconnected;
 281                 break;
 282
 283         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 284                 break;
 285
 286         case RDMA_CM_EVENT_ADDR_CHANGE:
 287         case RDMA_CM_EVENT_ROUTE_ERROR:
 288         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 289         case RDMA_CM_EVENT_MULTICAST_JOIN:
 290         case RDMA_CM_EVENT_MULTICAST_ERROR:
 291         case RDMA_CM_EVENT_REJECTED:
 292         case RDMA_CM_EVENT_CONNECT_REQUEST:
 293         case RDMA_CM_EVENT_CONNECT_RESPONSE:
 294         case RDMA_CM_EVENT_CONNECT_ERROR:
 295         case RDMA_CM_EVENT_ADDR_ERROR:
 296         case RDMA_CM_EVENT_UNREACHABLE:
 297                 c->status = Disconnected;
 298                 rdma_disconnect(rdma->cm_id);
 299                 break;
 300         default:
 301                 BUG();
 302         }
 303         complete(&rdma->cm_done);
 304         return 0;
 305 }
 306
 307 static void
 308 recv_done(struct ib_cq *cq, struct ib_wc *wc)
 309 {
 310         struct p9_client *client = cq->cq_context;
 311         struct p9_trans_rdma *rdma = client->trans;
 312         struct p9_rdma_context *c =
 313                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 314         struct p9_req_t *req;
 315         int err = 0;
 316         int16_t tag;
 317
 318         req = NULL;
 319         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
 320                                                          DMA_FROM_DEVICE);
 321
 322         if (wc->status != IB_WC_SUCCESS)
 323                 goto err_out;
 324
 325         err = p9_parse_header(c->rc, NULL, NULL, &tag, 1);
 326         if (err)
 327                 goto err_out;
 328
 329         req = p9_tag_lookup(client, tag);
 330         if (!req)
 331                 goto err_out;
 332
 333         /* Check that we have not yet received a reply for this request.
 334          */
 335         if (unlikely(req->rc)) {
 336                 pr_err("Duplicate reply for request %d", tag);
 337                 goto err_out;
 338         }
 339
 340         req->rc = c->rc;
 341         p9_client_cb(client, req, REQ_STATUS_RCVD);
 342
 343  out:
 344         up(&rdma->rq_sem);
 345         kfree(c);
 346         return;
 347
 348  err_out:
 349         p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
 350                         req, err, wc->status);
 351         rdma->state = P9_RDMA_FLUSHING;
 352         client->status = Disconnected;
 353         goto out;
 354 }
 355
 356 static void
 357 send_done(struct ib_cq *cq, struct ib_wc *wc)
 358 {
 359         struct p9_client *client = cq->cq_context;
 360         struct p9_trans_rdma *rdma = client->trans;
 361         struct p9_rdma_context *c =
 362                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 363
 364         ib_dma_unmap_single(rdma->cm_id->device,
 365                             c->busa, c->req->tc->size,
 366                             DMA_TO_DEVICE);
 367         up(&rdma->sq_sem);
 368         kfree(c);
 369 }
 370
 371 static void qp_event_handler(struct ib_event *event, void *context)
 372 {
 373         p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
 374                  event->event, context);
 375 }
 376
 377 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
 378 {
 379         if (!rdma)
 380                 return;
 381
 382         if (rdma->qp && !IS_ERR(rdma->qp))
 383                 ib_destroy_qp(rdma->qp);
 384
 385         if (rdma->pd && !IS_ERR(rdma->pd))
 386                 ib_dealloc_pd(rdma->pd);
 387
 388         if (rdma->cq && !IS_ERR(rdma->cq))
 389                 ib_free_cq(rdma->cq);
 390
 391         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
 392                 rdma_destroy_id(rdma->cm_id);
 393
 394         kfree(rdma);
 395 }
 396
 397 static int
 398 post_recv(struct p9_client *client, struct p9_rdma_context *c)
 399 {
 400         struct p9_trans_rdma *rdma = client->trans;
 401         struct ib_recv_wr wr, *bad_wr;
 402         struct ib_sge sge;
 403
 404         c->busa = ib_dma_map_single(rdma->cm_id->device,
 405                                     c->rc->sdata, client->msize,
 406                                     DMA_FROM_DEVICE);
 407         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
 408                 goto error;
 409
 410         c->cqe.done = recv_done;
 411
 412         sge.addr = c->busa;
 413         sge.length = client->msize;
 414         sge.lkey = rdma->pd->local_dma_lkey;
 415
 416         wr.next = NULL;
 417         wr.wr_cqe = &c->cqe;
 418         wr.sg_list = &sge;
 419         wr.num_sge = 1;
 420         return ib_post_recv(rdma->qp, &wr, &bad_wr);
 421
 422  error:
 423         p9_debug(P9_DEBUG_ERROR, "EIO\n");
 424         return -EIO;
 425 }
 426
 427 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 428 {
 429         struct p9_trans_rdma *rdma = client->trans;
 430         struct ib_send_wr wr, *bad_wr;
 431         struct ib_sge sge;
 432         int err = 0;
 433         unsigned long flags;
 434         struct p9_rdma_context *c = NULL;
 435         struct p9_rdma_context *rpl_context = NULL;
 436
 437         /* When an error occurs between posting the recv and the send,
 438          * there will be a receive context posted without a pending request.
 439          * Since there is no way to "un-post" it, we remember it and skip
 440          * post_recv() for the next request.
 441          * So here,
 442          * see if we are this `next request' and need to absorb an excess rc.
 443          * If yes, then drop and free our own, and do not recv_post().
 444          **/
 445         if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
 446                 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
 447                         /* Got one ! */
 448                         kfree(req->rc);
 449                         req->rc = NULL;
 450                         goto dont_need_post_recv;
 451                 } else {
 452                         /* We raced and lost. */
 453                         atomic_inc(&rdma->excess_rc);
 454                 }
 455         }
 456
 457         /* Allocate an fcall for the reply */
 458         rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
 459         if (!rpl_context) {
 460                 err = -ENOMEM;
 461                 goto recv_error;
 462         }
 463         rpl_context->rc = req->rc;
 464
 465         /*
 466          * Post a receive buffer for this request. We need to ensure
 467          * there is a reply buffer available for every outstanding
 468          * request. A flushed request can result in no reply for an
 469          * outstanding request, so we must keep a count to avoid
 470          * overflowing the RQ.
 471          */
 472         if (down_interruptible(&rdma->rq_sem)) {
 473                 err = -EINTR;
 474                 goto recv_error;
 475         }
 476
 477         err = post_recv(client, rpl_context);
 478         if (err) {
 479                 p9_debug(P9_DEBUG_FCALL, "POST RECV failed\n");
 480                 goto recv_error;
 481         }
 482         /* remove posted receive buffer from request structure */
 483         req->rc = NULL;
 484
 485 dont_need_post_recv:
 486         /* Post the request */
 487         c = kmalloc(sizeof *c, GFP_NOFS);
 488         if (!c) {
 489                 err = -ENOMEM;
 490                 goto send_error;
 491         }
 492         c->req = req;
 493
 494         c->busa = ib_dma_map_single(rdma->cm_id->device,
 495                                     c->req->tc->sdata, c->req->tc->size,
 496                                     DMA_TO_DEVICE);
 497         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
 498                 err = -EIO;
 499                 goto send_error;
 500         }
 501
 502         c->cqe.done = send_done;
 503
 504         sge.addr = c->busa;
 505         sge.length = c->req->tc->size;
 506         sge.lkey = rdma->pd->local_dma_lkey;
 507
 508         wr.next = NULL;
 509         wr.wr_cqe = &c->cqe;
 510         wr.opcode = IB_WR_SEND;
 511         wr.send_flags = IB_SEND_SIGNALED;
 512         wr.sg_list = &sge;
 513         wr.num_sge = 1;
 514
 515         if (down_interruptible(&rdma->sq_sem)) {
 516                 err = -EINTR;
 517                 goto send_error;
 518         }
 519
 520         /* Mark request as `sent' *before* we actually send it,
 521          * because doing if after could erase the REQ_STATUS_RCVD
 522          * status in case of a very fast reply.
 523          */
 524         req->status = REQ_STATUS_SENT;
 525         err = ib_post_send(rdma->qp, &wr, &bad_wr);
 526         if (err)
 527                 goto send_error;
 528
 529         /* Success */
 530         return 0;
 531
 532  /* Handle errors that happened during or while preparing the send: */
 533  send_error:
 534         req->status = REQ_STATUS_ERROR;
 535         kfree(c);
 536         p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
 537
 538         /* Ach.
 539          *  We did recv_post(), but not send. We have one recv_post in excess.
 540          */
 541         atomic_inc(&rdma->excess_rc);
 542         return err;
 543
 544  /* Handle errors that happened during or while preparing post_recv(): */
 545  recv_error:
 546         kfree(rpl_context);
 547         spin_lock_irqsave(&rdma->req_lock, flags);
 548         if (rdma->state < P9_RDMA_CLOSING) {
 549                 rdma->state = P9_RDMA_CLOSING;
 550                 spin_unlock_irqrestore(&rdma->req_lock, flags);
 551                 rdma_disconnect(rdma->cm_id);
 552         } else
 553                 spin_unlock_irqrestore(&rdma->req_lock, flags);
 554         return err;
 555 }
 556
 557 static void rdma_close(struct p9_client *client)
 558 {
 559         struct p9_trans_rdma *rdma;
 560
 561         if (!client)
 562                 return;
 563
 564         rdma = client->trans;
 565         if (!rdma)
 566                 return;
 567
 568         client->status = Disconnected;
 569         rdma_disconnect(rdma->cm_id);
 570         rdma_destroy_trans(rdma);
 571 }
 572
 573 /**
 574  * alloc_rdma - Allocate and initialize the rdma transport structure
 575  * @opts: Mount options structure
 576  */
 577 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
 578 {
 579         struct p9_trans_rdma *rdma;
 580
 581         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
 582         if (!rdma)
 583                 return NULL;
 584
 585         rdma->port = opts->port;
 586         rdma->privport = opts->privport;
 587         rdma->sq_depth = opts->sq_depth;
 588         rdma->rq_depth = opts->rq_depth;
 589         rdma->timeout = opts->timeout;
 590         spin_lock_init(&rdma->req_lock);
 591         init_completion(&rdma->cm_done);
 592         sema_init(&rdma->sq_sem, rdma->sq_depth);
 593         sema_init(&rdma->rq_sem, rdma->rq_depth);
 594         atomic_set(&rdma->excess_rc, 0);
 595
 596         return rdma;
 597 }
 598
 599 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
 600 {
 601         /* Nothing to do here.
 602          * We will take care of it (if we have to) in rdma_cancelled()
 603          */
 604         return 1;
 605 }
 606
 607 /* A request has been fully flushed without a reply.
 608  * That means we have posted one buffer in excess.
 609  */
 610 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
 611 {
 612         struct p9_trans_rdma *rdma = client->trans;
 613         atomic_inc(&rdma->excess_rc);
 614         return 0;
 615 }
 616
 617 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
 618 {
 619         struct sockaddr_in cl = {
 620                 .sin_family = AF_INET,
 621                 .sin_addr.s_addr = htonl(INADDR_ANY),
 622         };
 623         int port, err = -EINVAL;
 624
 625         for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
 626                 cl.sin_port = htons((ushort)port);
 627                 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
 628                 if (err != -EADDRINUSE)
 629                         break;
 630         }
 631         return err;
 632 }
 633
 634 /**
 635  * trans_create_rdma - Transport method for creating atransport instance
 636  * @client: client instance
 637  * @addr: IP address string
 638  * @args: Mount options string
 639  */
 640 static int
 641 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
 642 {
 643         int err;
 644         struct p9_rdma_opts opts;
 645         struct p9_trans_rdma *rdma;
 646         struct rdma_conn_param conn_param;
 647         struct ib_qp_init_attr qp_attr;
 648
 649         /* Parse the transport specific mount options */
 650         err = parse_opts(args, &opts);
 651         if (err < 0)
 652                 return err;
 653
 654         /* Create and initialize the RDMA transport structure */
 655         rdma = alloc_rdma(&opts);
 656         if (!rdma)
 657                 return -ENOMEM;
 658
 659         /* Create the RDMA CM ID */
 660         rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
 661                                      RDMA_PS_TCP, IB_QPT_RC);
 662         if (IS_ERR(rdma->cm_id))
 663                 goto error;
 664
 665         /* Associate the client with the transport */
 666         client->trans = rdma;
 667
 668         /* Bind to a privileged port if we need to */
 669         if (opts.privport) {
 670                 err = p9_rdma_bind_privport(rdma);
 671                 if (err < 0) {
 672                         pr_err("%s (%d): problem binding to privport: %d\n",
 673                                __func__, task_pid_nr(current), -err);
 674                         goto error;
 675                 }
 676         }
 677
 678         /* Resolve the server's address */
 679         rdma->addr.sin_family = AF_INET;
 680         rdma->addr.sin_addr.s_addr = in_aton(addr);
 681         rdma->addr.sin_port = htons(opts.port);
 682         err = rdma_resolve_addr(rdma->cm_id, NULL,
 683                                 (struct sockaddr *)&rdma->addr,
 684                                 rdma->timeout);
 685         if (err)
 686                 goto error;
 687         err = wait_for_completion_interruptible(&rdma->cm_done);
 688         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
 689                 goto error;
 690
 691         /* Resolve the route to the server */
 692         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
 693         if (err)
 694                 goto error;
 695         err = wait_for_completion_interruptible(&rdma->cm_done);
 696         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
 697                 goto error;
 698
 699         /* Create the Completion Queue */
 700         rdma->cq = ib_alloc_cq(rdma->cm_id->device, client,
 701                         opts.sq_depth + opts.rq_depth + 1,
 702                         0, IB_POLL_SOFTIRQ);
 703         if (IS_ERR(rdma->cq))
 704                 goto error;
 705
 706         /* Create the Protection Domain */
 707         rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
 708         if (IS_ERR(rdma->pd))
 709                 goto error;
 710
 711         /* Create the Queue Pair */
 712         memset(&qp_attr, 0, sizeof qp_attr);
 713         qp_attr.event_handler = qp_event_handler;
 714         qp_attr.qp_context = client;
 715         qp_attr.cap.max_send_wr = opts.sq_depth;
 716         qp_attr.cap.max_recv_wr = opts.rq_depth;
 717         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
 718         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
 719         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 720         qp_attr.qp_type = IB_QPT_RC;
 721         qp_attr.send_cq = rdma->cq;
 722         qp_attr.recv_cq = rdma->cq;
 723         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
 724         if (err)
 725                 goto error;
 726         rdma->qp = rdma->cm_id->qp;
 727
 728         /* Request a connection */
 729         memset(&conn_param, 0, sizeof(conn_param));
 730         conn_param.private_data = NULL;
 731         conn_param.private_data_len = 0;
 732         conn_param.responder_resources = P9_RDMA_IRD;
 733         conn_param.initiator_depth = P9_RDMA_ORD;
 734         err = rdma_connect(rdma->cm_id, &conn_param);
 735         if (err)
 736                 goto error;
 737         err = wait_for_completion_interruptible(&rdma->cm_done);
 738         if (err || (rdma->state != P9_RDMA_CONNECTED))
 739                 goto error;
 740
 741         client->status = Connected;
 742
 743         return 0;
 744
 745 error:
 746         rdma_destroy_trans(rdma);
 747         return -ENOTCONN;
 748 }
 749
 750 static struct p9_trans_module p9_rdma_trans = {
 751         .name = "rdma",
 752         .maxsize = P9_RDMA_MAXSIZE,
 753         .def = 0,
 754         .owner = THIS_MODULE,
 755         .create = rdma_create_trans,
 756         .close = rdma_close,
 757         .request = rdma_request,
 758         .cancel = rdma_cancel,
 759         .cancelled = rdma_cancelled,
 760         .show_options = p9_rdma_show_options,
 761 };
 762
 763 /**
 764  * p9_trans_rdma_init - Register the 9P RDMA transport driver
 765  */
 766 static int __init p9_trans_rdma_init(void)
 767 {
 768         v9fs_register_trans(&p9_rdma_trans);
 769         return 0;
 770 }
 771
 772 static void __exit p9_trans_rdma_exit(void)
 773 {
 774         v9fs_unregister_trans(&p9_rdma_trans);
 775 }
 776
 777 module_init(p9_trans_rdma_init);
 778 module_exit(p9_trans_rdma_exit);
 779
 780 MODULE_AUTHOR("Tom Tucker <[email protected]>");
 781 MODULE_DESCRIPTION("RDMA Transport for 9P");
 782 MODULE_LICENSE("Dual BSD/GPL");