net/9p/trans_rdma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * RDMA transport layer based on the trans_fd.c implementation.
   4  *
   5  *  Copyright (C) 2008 by Tom Tucker <tom@opengridcomputing.com>
   6  *  Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
   7  *  Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
   8  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   9  *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/in.h>
  15 #include <linux/module.h>
  16 #include <linux/net.h>
  17 #include <linux/ipv6.h>
  18 #include <linux/kthread.h>
  19 #include <linux/errno.h>
  20 #include <linux/kernel.h>
  21 #include <linux/un.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/inet.h>
  24 #include <linux/file.h>
  25 #include <linux/parser.h>
  26 #include <linux/semaphore.h>
  27 #include <linux/slab.h>
  28 #include <linux/seq_file.h>
  29 #include <net/9p/9p.h>
  30 #include <net/9p/client.h>
  31 #include <net/9p/transport.h>
  32 #include <rdma/ib_verbs.h>
  33 #include <rdma/rdma_cm.h>
  34
  35 #define P9_PORT                 5640
  36 #define P9_RDMA_SQ_DEPTH        32
  37 #define P9_RDMA_RQ_DEPTH        32
  38 #define P9_RDMA_SEND_SGE        4
  39 #define P9_RDMA_RECV_SGE        4
  40 #define P9_RDMA_IRD             0
  41 #define P9_RDMA_ORD             0
  42 #define P9_RDMA_TIMEOUT         30000           /* 30 seconds */
  43 #define P9_RDMA_MAXSIZE         (1024*1024)     /* 1MB */
  44
  45 /**
  46  * struct p9_trans_rdma - RDMA transport instance
  47  *
  48  * @state: tracks the transport state machine for connection setup and tear down
  49  * @cm_id: The RDMA CM ID
  50  * @pd: Protection Domain pointer
  51  * @qp: Queue Pair pointer
  52  * @cq: Completion Queue pointer
  53  * @timeout: Number of uSecs to wait for connection management events
  54  * @privport: Whether a privileged port may be used
  55  * @port: The port to use
  56  * @sq_depth: The depth of the Send Queue
  57  * @sq_sem: Semaphore for the SQ
  58  * @rq_depth: The depth of the Receive Queue.
  59  * @rq_sem: Semaphore for the RQ
  60  * @excess_rc : Amount of posted Receive Contexts without a pending request.
  61  *              See rdma_request()
  62  * @addr: The remote peer's address
  63  * @req_lock: Protects the active request list
  64  * @cm_done: Completion event for connection management tracking
  65  */
  66 struct p9_trans_rdma {
  67         enum {
  68                 P9_RDMA_INIT,
  69                 P9_RDMA_ADDR_RESOLVED,
  70                 P9_RDMA_ROUTE_RESOLVED,
  71                 P9_RDMA_CONNECTED,
  72                 P9_RDMA_FLUSHING,
  73                 P9_RDMA_CLOSING,
  74                 P9_RDMA_CLOSED,
  75         } state;
  76         struct rdma_cm_id *cm_id;
  77         struct ib_pd *pd;
  78         struct ib_qp *qp;
  79         struct ib_cq *cq;
  80         long timeout;
  81         bool privport;
  82         u16 port;
  83         int sq_depth;
  84         struct semaphore sq_sem;
  85         int rq_depth;
  86         struct semaphore rq_sem;
  87         atomic_t excess_rc;
  88         struct sockaddr_in addr;
  89         spinlock_t req_lock;
  90
  91         struct completion cm_done;
  92 };
  93
  94 struct p9_rdma_req;
  95
  96 /**
  97  * struct p9_rdma_context - Keeps track of in-process WR
  98  *
  99  * @cqe: completion queue entry
 100  * @busa: Bus address to unmap when the WR completes
 101  * @req: Keeps track of requests (send)
 102  * @rc: Keepts track of replies (receive)
 103  */
 104 struct p9_rdma_context {
 105         struct ib_cqe cqe;
 106         dma_addr_t busa;
 107         union {
 108                 struct p9_req_t *req;
 109                 struct p9_fcall rc;
 110         };
 111 };
 112
 113 /**
 114  * struct p9_rdma_opts - Collection of mount options
 115  * @port: port of connection
 116  * @privport: Whether a privileged port may be used
 117  * @sq_depth: The requested depth of the SQ. This really doesn't need
 118  * to be any deeper than the number of threads used in the client
 119  * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
 120  * @timeout: Time to wait in msecs for CM events
 121  */
 122 struct p9_rdma_opts {
 123         short port;
 124         bool privport;
 125         int sq_depth;
 126         int rq_depth;
 127         long timeout;
 128 };
 129
 130 /*
 131  * Option Parsing (code inspired by NFS code)
 132  */
 133 enum {
 134         /* Options that take integer arguments */
 135         Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout,
 136         /* Options that take no argument */
 137         Opt_privport,
 138         Opt_err,
 139 };
 140
 141 static match_table_t tokens = {
 142         {Opt_port, "port=%u"},
 143         {Opt_sq_depth, "sq=%u"},
 144         {Opt_rq_depth, "rq=%u"},
 145         {Opt_timeout, "timeout=%u"},
 146         {Opt_privport, "privport"},
 147         {Opt_err, NULL},
 148 };
 149
 150 static int p9_rdma_show_options(struct seq_file *m, struct p9_client *clnt)
 151 {
 152         struct p9_trans_rdma *rdma = clnt->trans;
 153
 154         if (rdma->port != P9_PORT)
 155                 seq_printf(m, ",port=%u", rdma->port);
 156         if (rdma->sq_depth != P9_RDMA_SQ_DEPTH)
 157                 seq_printf(m, ",sq=%u", rdma->sq_depth);
 158         if (rdma->rq_depth != P9_RDMA_RQ_DEPTH)
 159                 seq_printf(m, ",rq=%u", rdma->rq_depth);
 160         if (rdma->timeout != P9_RDMA_TIMEOUT)
 161                 seq_printf(m, ",timeout=%lu", rdma->timeout);
 162         if (rdma->privport)
 163                 seq_puts(m, ",privport");
 164         return 0;
 165 }
 166
 167 /**
 168  * parse_opts - parse mount options into rdma options structure
 169  * @params: options string passed from mount
 170  * @opts: rdma transport-specific structure to parse options into
 171  *
 172  * Returns 0 upon success, -ERRNO upon failure
 173  */
 174 static int parse_opts(char *params, struct p9_rdma_opts *opts)
 175 {
 176         char *p;
 177         substring_t args[MAX_OPT_ARGS];
 178         int option;
 179         char *options, *tmp_options;
 180
 181         opts->port = P9_PORT;
 182         opts->sq_depth = P9_RDMA_SQ_DEPTH;
 183         opts->rq_depth = P9_RDMA_RQ_DEPTH;
 184         opts->timeout = P9_RDMA_TIMEOUT;
 185         opts->privport = false;
 186
 187         if (!params)
 188                 return 0;
 189
 190         tmp_options = kstrdup(params, GFP_KERNEL);
 191         if (!tmp_options) {
 192                 p9_debug(P9_DEBUG_ERROR,
 193                          "failed to allocate copy of option string\n");
 194                 return -ENOMEM;
 195         }
 196         options = tmp_options;
 197
 198         while ((p = strsep(&options, ",")) != NULL) {
 199                 int token;
 200                 int r;
 201                 if (!*p)
 202                         continue;
 203                 token = match_token(p, tokens, args);
 204                 if ((token != Opt_err) && (token != Opt_privport)) {
 205                         r = match_int(&args[0], &option);
 206                         if (r < 0) {
 207                                 p9_debug(P9_DEBUG_ERROR,
 208                                          "integer field, but no integer?\n");
 209                                 continue;
 210                         }
 211                 }
 212                 switch (token) {
 213                 case Opt_port:
 214                         opts->port = option;
 215                         break;
 216                 case Opt_sq_depth:
 217                         opts->sq_depth = option;
 218                         break;
 219                 case Opt_rq_depth:
 220                         opts->rq_depth = option;
 221                         break;
 222                 case Opt_timeout:
 223                         opts->timeout = option;
 224                         break;
 225                 case Opt_privport:
 226                         opts->privport = true;
 227                         break;
 228                 default:
 229                         continue;
 230                 }
 231         }
 232         /* RQ must be at least as large as the SQ */
 233         opts->rq_depth = max(opts->rq_depth, opts->sq_depth);
 234         kfree(tmp_options);
 235         return 0;
 236 }
 237
 238 static int
 239 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
 240 {
 241         struct p9_client *c = id->context;
 242         struct p9_trans_rdma *rdma = c->trans;
 243         switch (event->event) {
 244         case RDMA_CM_EVENT_ADDR_RESOLVED:
 245                 BUG_ON(rdma->state != P9_RDMA_INIT);
 246                 rdma->state = P9_RDMA_ADDR_RESOLVED;
 247                 break;
 248
 249         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 250                 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED);
 251                 rdma->state = P9_RDMA_ROUTE_RESOLVED;
 252                 break;
 253
 254         case RDMA_CM_EVENT_ESTABLISHED:
 255                 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED);
 256                 rdma->state = P9_RDMA_CONNECTED;
 257                 break;
 258
 259         case RDMA_CM_EVENT_DISCONNECTED:
 260                 if (rdma)
 261                         rdma->state = P9_RDMA_CLOSED;
 262                 c->status = Disconnected;
 263                 break;
 264
 265         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 266                 break;
 267
 268         case RDMA_CM_EVENT_ADDR_CHANGE:
 269         case RDMA_CM_EVENT_ROUTE_ERROR:
 270         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 271         case RDMA_CM_EVENT_MULTICAST_JOIN:
 272         case RDMA_CM_EVENT_MULTICAST_ERROR:
 273         case RDMA_CM_EVENT_REJECTED:
 274         case RDMA_CM_EVENT_CONNECT_REQUEST:
 275         case RDMA_CM_EVENT_CONNECT_RESPONSE:
 276         case RDMA_CM_EVENT_CONNECT_ERROR:
 277         case RDMA_CM_EVENT_ADDR_ERROR:
 278         case RDMA_CM_EVENT_UNREACHABLE:
 279                 c->status = Disconnected;
 280                 rdma_disconnect(rdma->cm_id);
 281                 break;
 282         default:
 283                 BUG();
 284         }
 285         complete(&rdma->cm_done);
 286         return 0;
 287 }
 288
 289 static void
 290 recv_done(struct ib_cq *cq, struct ib_wc *wc)
 291 {
 292         struct p9_client *client = cq->cq_context;
 293         struct p9_trans_rdma *rdma = client->trans;
 294         struct p9_rdma_context *c =
 295                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 296         struct p9_req_t *req;
 297         int err = 0;
 298         int16_t tag;
 299
 300         req = NULL;
 301         ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize,
 302                                                          DMA_FROM_DEVICE);
 303
 304         if (wc->status != IB_WC_SUCCESS)
 305                 goto err_out;
 306
 307         c->rc.size = wc->byte_len;
 308         err = p9_parse_header(&c->rc, NULL, NULL, &tag, 1);
 309         if (err)
 310                 goto err_out;
 311
 312         req = p9_tag_lookup(client, tag);
 313         if (!req)
 314                 goto err_out;
 315
 316         /* Check that we have not yet received a reply for this request.
 317          */
 318         if (unlikely(req->rc.sdata)) {
 319                 pr_err("Duplicate reply for request %d", tag);
 320                 goto err_out;
 321         }
 322
 323         req->rc.size = c->rc.size;
 324         req->rc.sdata = c->rc.sdata;
 325         p9_client_cb(client, req, REQ_STATUS_RCVD);
 326
 327  out:
 328         up(&rdma->rq_sem);
 329         kfree(c);
 330         return;
 331
 332  err_out:
 333         p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n",
 334                         req, err, wc->status);
 335         rdma->state = P9_RDMA_FLUSHING;
 336         client->status = Disconnected;
 337         goto out;
 338 }
 339
 340 static void
 341 send_done(struct ib_cq *cq, struct ib_wc *wc)
 342 {
 343         struct p9_client *client = cq->cq_context;
 344         struct p9_trans_rdma *rdma = client->trans;
 345         struct p9_rdma_context *c =
 346                 container_of(wc->wr_cqe, struct p9_rdma_context, cqe);
 347
 348         ib_dma_unmap_single(rdma->cm_id->device,
 349                             c->busa, c->req->tc.size,
 350                             DMA_TO_DEVICE);
 351         up(&rdma->sq_sem);
 352         p9_req_put(client, c->req);
 353         kfree(c);
 354 }
 355
 356 static void qp_event_handler(struct ib_event *event, void *context)
 357 {
 358         p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n",
 359                  event->event, context);
 360 }
 361
 362 static void rdma_destroy_trans(struct p9_trans_rdma *rdma)
 363 {
 364         if (!rdma)
 365                 return;
 366
 367         if (rdma->qp && !IS_ERR(rdma->qp))
 368                 ib_destroy_qp(rdma->qp);
 369
 370         if (rdma->pd && !IS_ERR(rdma->pd))
 371                 ib_dealloc_pd(rdma->pd);
 372
 373         if (rdma->cq && !IS_ERR(rdma->cq))
 374                 ib_free_cq(rdma->cq);
 375
 376         if (rdma->cm_id && !IS_ERR(rdma->cm_id))
 377                 rdma_destroy_id(rdma->cm_id);
 378
 379         kfree(rdma);
 380 }
 381
 382 static int
 383 post_recv(struct p9_client *client, struct p9_rdma_context *c)
 384 {
 385         struct p9_trans_rdma *rdma = client->trans;
 386         struct ib_recv_wr wr;
 387         struct ib_sge sge;
 388         int ret;
 389
 390         c->busa = ib_dma_map_single(rdma->cm_id->device,
 391                                     c->rc.sdata, client->msize,
 392                                     DMA_FROM_DEVICE);
 393         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa))
 394                 goto error;
 395
 396         c->cqe.done = recv_done;
 397
 398         sge.addr = c->busa;
 399         sge.length = client->msize;
 400         sge.lkey = rdma->pd->local_dma_lkey;
 401
 402         wr.next = NULL;
 403         wr.wr_cqe = &c->cqe;
 404         wr.sg_list = &sge;
 405         wr.num_sge = 1;
 406
 407         ret = ib_post_recv(rdma->qp, &wr, NULL);
 408         if (ret)
 409                 ib_dma_unmap_single(rdma->cm_id->device, c->busa,
 410                                     client->msize, DMA_FROM_DEVICE);
 411         return ret;
 412
 413  error:
 414         p9_debug(P9_DEBUG_ERROR, "EIO\n");
 415         return -EIO;
 416 }
 417
 418 static int rdma_request(struct p9_client *client, struct p9_req_t *req)
 419 {
 420         struct p9_trans_rdma *rdma = client->trans;
 421         struct ib_send_wr wr;
 422         struct ib_sge sge;
 423         int err = 0;
 424         unsigned long flags;
 425         struct p9_rdma_context *c = NULL;
 426         struct p9_rdma_context *rpl_context = NULL;
 427
 428         /* When an error occurs between posting the recv and the send,
 429          * there will be a receive context posted without a pending request.
 430          * Since there is no way to "un-post" it, we remember it and skip
 431          * post_recv() for the next request.
 432          * So here,
 433          * see if we are this `next request' and need to absorb an excess rc.
 434          * If yes, then drop and free our own, and do not recv_post().
 435          **/
 436         if (unlikely(atomic_read(&rdma->excess_rc) > 0)) {
 437                 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) {
 438                         /* Got one! */
 439                         p9_fcall_fini(&req->rc);
 440                         req->rc.sdata = NULL;
 441                         goto dont_need_post_recv;
 442                 } else {
 443                         /* We raced and lost. */
 444                         atomic_inc(&rdma->excess_rc);
 445                 }
 446         }
 447
 448         /* Allocate an fcall for the reply */
 449         rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS);
 450         if (!rpl_context) {
 451                 err = -ENOMEM;
 452                 goto recv_error;
 453         }
 454         rpl_context->rc.sdata = req->rc.sdata;
 455
 456         /*
 457          * Post a receive buffer for this request. We need to ensure
 458          * there is a reply buffer available for every outstanding
 459          * request. A flushed request can result in no reply for an
 460          * outstanding request, so we must keep a count to avoid
 461          * overflowing the RQ.
 462          */
 463         if (down_interruptible(&rdma->rq_sem)) {
 464                 err = -EINTR;
 465                 goto recv_error;
 466         }
 467
 468         err = post_recv(client, rpl_context);
 469         if (err) {
 470                 p9_debug(P9_DEBUG_ERROR, "POST RECV failed: %d\n", err);
 471                 goto recv_error;
 472         }
 473         /* remove posted receive buffer from request structure */
 474         req->rc.sdata = NULL;
 475
 476 dont_need_post_recv:
 477         /* Post the request */
 478         c = kmalloc(sizeof *c, GFP_NOFS);
 479         if (!c) {
 480                 err = -ENOMEM;
 481                 goto send_error;
 482         }
 483         c->req = req;
 484
 485         c->busa = ib_dma_map_single(rdma->cm_id->device,
 486                                     c->req->tc.sdata, c->req->tc.size,
 487                                     DMA_TO_DEVICE);
 488         if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) {
 489                 err = -EIO;
 490                 goto send_error;
 491         }
 492
 493         c->cqe.done = send_done;
 494
 495         sge.addr = c->busa;
 496         sge.length = c->req->tc.size;
 497         sge.lkey = rdma->pd->local_dma_lkey;
 498
 499         wr.next = NULL;
 500         wr.wr_cqe = &c->cqe;
 501         wr.opcode = IB_WR_SEND;
 502         wr.send_flags = IB_SEND_SIGNALED;
 503         wr.sg_list = &sge;
 504         wr.num_sge = 1;
 505
 506         if (down_interruptible(&rdma->sq_sem)) {
 507                 err = -EINTR;
 508                 goto dma_unmap;
 509         }
 510
 511         /* Mark request as `sent' *before* we actually send it,
 512          * because doing if after could erase the REQ_STATUS_RCVD
 513          * status in case of a very fast reply.
 514          */
 515         WRITE_ONCE(req->status, REQ_STATUS_SENT);
 516         err = ib_post_send(rdma->qp, &wr, NULL);
 517         if (err)
 518                 goto dma_unmap;
 519
 520         /* Success */
 521         return 0;
 522
 523 dma_unmap:
 524         ib_dma_unmap_single(rdma->cm_id->device, c->busa,
 525                             c->req->tc.size, DMA_TO_DEVICE);
 526  /* Handle errors that happened during or while preparing the send: */
 527  send_error:
 528         WRITE_ONCE(req->status, REQ_STATUS_ERROR);
 529         kfree(c);
 530         p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err);
 531
 532         /* Ach.
 533          *  We did recv_post(), but not send. We have one recv_post in excess.
 534          */
 535         atomic_inc(&rdma->excess_rc);
 536         return err;
 537
 538  /* Handle errors that happened during or while preparing post_recv(): */
 539  recv_error:
 540         kfree(rpl_context);
 541         spin_lock_irqsave(&rdma->req_lock, flags);
 542         if (err != -EINTR && rdma->state < P9_RDMA_CLOSING) {
 543                 rdma->state = P9_RDMA_CLOSING;
 544                 spin_unlock_irqrestore(&rdma->req_lock, flags);
 545                 rdma_disconnect(rdma->cm_id);
 546         } else
 547                 spin_unlock_irqrestore(&rdma->req_lock, flags);
 548         return err;
 549 }
 550
 551 static void rdma_close(struct p9_client *client)
 552 {
 553         struct p9_trans_rdma *rdma;
 554
 555         if (!client)
 556                 return;
 557
 558         rdma = client->trans;
 559         if (!rdma)
 560                 return;
 561
 562         client->status = Disconnected;
 563         rdma_disconnect(rdma->cm_id);
 564         rdma_destroy_trans(rdma);
 565 }
 566
 567 /**
 568  * alloc_rdma - Allocate and initialize the rdma transport structure
 569  * @opts: Mount options structure
 570  */
 571 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts)
 572 {
 573         struct p9_trans_rdma *rdma;
 574
 575         rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL);
 576         if (!rdma)
 577                 return NULL;
 578
 579         rdma->port = opts->port;
 580         rdma->privport = opts->privport;
 581         rdma->sq_depth = opts->sq_depth;
 582         rdma->rq_depth = opts->rq_depth;
 583         rdma->timeout = opts->timeout;
 584         spin_lock_init(&rdma->req_lock);
 585         init_completion(&rdma->cm_done);
 586         sema_init(&rdma->sq_sem, rdma->sq_depth);
 587         sema_init(&rdma->rq_sem, rdma->rq_depth);
 588         atomic_set(&rdma->excess_rc, 0);
 589
 590         return rdma;
 591 }
 592
 593 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req)
 594 {
 595         /* Nothing to do here.
 596          * We will take care of it (if we have to) in rdma_cancelled()
 597          */
 598         return 1;
 599 }
 600
 601 /* A request has been fully flushed without a reply.
 602  * That means we have posted one buffer in excess.
 603  */
 604 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req)
 605 {
 606         struct p9_trans_rdma *rdma = client->trans;
 607         atomic_inc(&rdma->excess_rc);
 608         return 0;
 609 }
 610
 611 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma)
 612 {
 613         struct sockaddr_in cl = {
 614                 .sin_family = AF_INET,
 615                 .sin_addr.s_addr = htonl(INADDR_ANY),
 616         };
 617         int port, err = -EINVAL;
 618
 619         for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) {
 620                 cl.sin_port = htons((ushort)port);
 621                 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl);
 622                 if (err != -EADDRINUSE)
 623                         break;
 624         }
 625         return err;
 626 }
 627
 628 /**
 629  * rdma_create_trans - Transport method for creating a transport instance
 630  * @client: client instance
 631  * @addr: IP address string
 632  * @args: Mount options string
 633  */
 634 static int
 635 rdma_create_trans(struct p9_client *client, const char *addr, char *args)
 636 {
 637         int err;
 638         struct p9_rdma_opts opts;
 639         struct p9_trans_rdma *rdma;
 640         struct rdma_conn_param conn_param;
 641         struct ib_qp_init_attr qp_attr;
 642
 643         if (addr == NULL)
 644                 return -EINVAL;
 645
 646         /* Parse the transport specific mount options */
 647         err = parse_opts(args, &opts);
 648         if (err < 0)
 649                 return err;
 650
 651         /* Create and initialize the RDMA transport structure */
 652         rdma = alloc_rdma(&opts);
 653         if (!rdma)
 654                 return -ENOMEM;
 655
 656         /* Create the RDMA CM ID */
 657         rdma->cm_id = rdma_create_id(&init_net, p9_cm_event_handler, client,
 658                                      RDMA_PS_TCP, IB_QPT_RC);
 659         if (IS_ERR(rdma->cm_id))
 660                 goto error;
 661
 662         /* Associate the client with the transport */
 663         client->trans = rdma;
 664
 665         /* Bind to a privileged port if we need to */
 666         if (opts.privport) {
 667                 err = p9_rdma_bind_privport(rdma);
 668                 if (err < 0) {
 669                         pr_err("%s (%d): problem binding to privport: %d\n",
 670                                __func__, task_pid_nr(current), -err);
 671                         goto error;
 672                 }
 673         }
 674
 675         /* Resolve the server's address */
 676         rdma->addr.sin_family = AF_INET;
 677         rdma->addr.sin_addr.s_addr = in_aton(addr);
 678         rdma->addr.sin_port = htons(opts.port);
 679         err = rdma_resolve_addr(rdma->cm_id, NULL,
 680                                 (struct sockaddr *)&rdma->addr,
 681                                 rdma->timeout);
 682         if (err)
 683                 goto error;
 684         err = wait_for_completion_interruptible(&rdma->cm_done);
 685         if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED))
 686                 goto error;
 687
 688         /* Resolve the route to the server */
 689         err = rdma_resolve_route(rdma->cm_id, rdma->timeout);
 690         if (err)
 691                 goto error;
 692         err = wait_for_completion_interruptible(&rdma->cm_done);
 693         if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED))
 694                 goto error;
 695
 696         /* Create the Completion Queue */
 697         rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
 698                                    opts.sq_depth + opts.rq_depth + 1,
 699                                    IB_POLL_SOFTIRQ);
 700         if (IS_ERR(rdma->cq))
 701                 goto error;
 702
 703         /* Create the Protection Domain */
 704         rdma->pd = ib_alloc_pd(rdma->cm_id->device, 0);
 705         if (IS_ERR(rdma->pd))
 706                 goto error;
 707
 708         /* Create the Queue Pair */
 709         memset(&qp_attr, 0, sizeof qp_attr);
 710         qp_attr.event_handler = qp_event_handler;
 711         qp_attr.qp_context = client;
 712         qp_attr.cap.max_send_wr = opts.sq_depth;
 713         qp_attr.cap.max_recv_wr = opts.rq_depth;
 714         qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE;
 715         qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE;
 716         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 717         qp_attr.qp_type = IB_QPT_RC;
 718         qp_attr.send_cq = rdma->cq;
 719         qp_attr.recv_cq = rdma->cq;
 720         err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr);
 721         if (err)
 722                 goto error;
 723         rdma->qp = rdma->cm_id->qp;
 724
 725         /* Request a connection */
 726         memset(&conn_param, 0, sizeof(conn_param));
 727         conn_param.private_data = NULL;
 728         conn_param.private_data_len = 0;
 729         conn_param.responder_resources = P9_RDMA_IRD;
 730         conn_param.initiator_depth = P9_RDMA_ORD;
 731         err = rdma_connect(rdma->cm_id, &conn_param);
 732         if (err)
 733                 goto error;
 734         err = wait_for_completion_interruptible(&rdma->cm_done);
 735         if (err || (rdma->state != P9_RDMA_CONNECTED))
 736                 goto error;
 737
 738         client->status = Connected;
 739
 740         return 0;
 741
 742 error:
 743         rdma_destroy_trans(rdma);
 744         return -ENOTCONN;
 745 }
 746
 747 static struct p9_trans_module p9_rdma_trans = {
 748         .name = "rdma",
 749         .maxsize = P9_RDMA_MAXSIZE,
 750         .pooled_rbuffers = true,
 751         .def = 0,
 752         .owner = THIS_MODULE,
 753         .create = rdma_create_trans,
 754         .close = rdma_close,
 755         .request = rdma_request,
 756         .cancel = rdma_cancel,
 757         .cancelled = rdma_cancelled,
 758         .show_options = p9_rdma_show_options,
 759 };
 760
 761 /**
 762  * p9_trans_rdma_init - Register the 9P RDMA transport driver
 763  */
 764 static int __init p9_trans_rdma_init(void)
 765 {
 766         v9fs_register_trans(&p9_rdma_trans);
 767         return 0;
 768 }
 769
 770 static void __exit p9_trans_rdma_exit(void)
 771 {
 772         v9fs_unregister_trans(&p9_rdma_trans);
 773 }
 774
 775 module_init(p9_trans_rdma_init);
 776 module_exit(p9_trans_rdma_exit);
 777 MODULE_ALIAS_9P("rdma");
 778
 779 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
 780 MODULE_DESCRIPTION("RDMA Transport for 9P");
 781 MODULE_LICENSE("Dual BSD/GPL");