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 <tom@opengridcomputing.com> 7 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com> 8 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net> 9 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com> 10 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com> 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 <net/9p/9p.h> 47 #include <net/9p/client.h> 48 #include <net/9p/transport.h> 49 #include <rdma/ib_verbs.h> 50 #include <rdma/rdma_cm.h> 51 52 #define P9_PORT 5640 53 #define P9_RDMA_SQ_DEPTH 32 54 #define P9_RDMA_RQ_DEPTH 32 55 #define P9_RDMA_SEND_SGE 4 56 #define P9_RDMA_RECV_SGE 4 57 #define P9_RDMA_IRD 0 58 #define P9_RDMA_ORD 0 59 #define P9_RDMA_TIMEOUT 30000 /* 30 seconds */ 60 #define P9_RDMA_MAXSIZE (1024*1024) /* 1MB */ 61 62 /** 63 * struct p9_trans_rdma - RDMA transport instance 64 * 65 * @state: tracks the transport state machine for connection setup and tear down 66 * @cm_id: The RDMA CM ID 67 * @pd: Protection Domain pointer 68 * @qp: Queue Pair pointer 69 * @cq: Completion Queue pointer 70 * @dm_mr: DMA Memory Region pointer 71 * @lkey: The local access only memory region key 72 * @timeout: Number of uSecs to wait for connection management events 73 * @sq_depth: The depth of the Send Queue 74 * @sq_sem: Semaphore for the SQ 75 * @rq_depth: The depth of the Receive Queue. 76 * @rq_sem: Semaphore for the RQ 77 * @excess_rc : Amount of posted Receive Contexts without a pending request. 78 * See rdma_request() 79 * @addr: The remote peer's address 80 * @req_lock: Protects the active request list 81 * @cm_done: Completion event for connection management tracking 82 */ 83 struct p9_trans_rdma { 84 enum { 85 P9_RDMA_INIT, 86 P9_RDMA_ADDR_RESOLVED, 87 P9_RDMA_ROUTE_RESOLVED, 88 P9_RDMA_CONNECTED, 89 P9_RDMA_FLUSHING, 90 P9_RDMA_CLOSING, 91 P9_RDMA_CLOSED, 92 } state; 93 struct rdma_cm_id *cm_id; 94 struct ib_pd *pd; 95 struct ib_qp *qp; 96 struct ib_cq *cq; 97 struct ib_mr *dma_mr; 98 u32 lkey; 99 long timeout; 100 int sq_depth; 101 struct semaphore sq_sem; 102 int rq_depth; 103 struct semaphore rq_sem; 104 atomic_t excess_rc; 105 struct sockaddr_in addr; 106 spinlock_t req_lock; 107 108 struct completion cm_done; 109 }; 110 111 /** 112 * p9_rdma_context - Keeps track of in-process WR 113 * 114 * @wc_op: The original WR op for when the CQE completes in error. 115 * @busa: Bus address to unmap when the WR completes 116 * @req: Keeps track of requests (send) 117 * @rc: Keepts track of replies (receive) 118 */ 119 struct p9_rdma_req; 120 struct p9_rdma_context { 121 enum ib_wc_opcode wc_op; 122 dma_addr_t busa; 123 union { 124 struct p9_req_t *req; 125 struct p9_fcall *rc; 126 }; 127 }; 128 129 /** 130 * p9_rdma_opts - Collection of mount options 131 * @port: port of connection 132 * @sq_depth: The requested depth of the SQ. This really doesn't need 133 * to be any deeper than the number of threads used in the client 134 * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth 135 * @timeout: Time to wait in msecs for CM events 136 */ 137 struct p9_rdma_opts { 138 short port; 139 int sq_depth; 140 int rq_depth; 141 long timeout; 142 int privport; 143 }; 144 145 /* 146 * Option Parsing (code inspired by NFS code) 147 */ 148 enum { 149 /* Options that take integer arguments */ 150 Opt_port, Opt_rq_depth, Opt_sq_depth, Opt_timeout, 151 /* Options that take no argument */ 152 Opt_privport, 153 Opt_err, 154 }; 155 156 static match_table_t tokens = { 157 {Opt_port, "port=%u"}, 158 {Opt_sq_depth, "sq=%u"}, 159 {Opt_rq_depth, "rq=%u"}, 160 {Opt_timeout, "timeout=%u"}, 161 {Opt_privport, "privport"}, 162 {Opt_err, NULL}, 163 }; 164 165 /** 166 * parse_opts - parse mount options into rdma options structure 167 * @params: options string passed from mount 168 * @opts: rdma transport-specific structure to parse options into 169 * 170 * Returns 0 upon success, -ERRNO upon failure 171 */ 172 static int parse_opts(char *params, struct p9_rdma_opts *opts) 173 { 174 char *p; 175 substring_t args[MAX_OPT_ARGS]; 176 int option; 177 char *options, *tmp_options; 178 179 opts->port = P9_PORT; 180 opts->sq_depth = P9_RDMA_SQ_DEPTH; 181 opts->rq_depth = P9_RDMA_RQ_DEPTH; 182 opts->timeout = P9_RDMA_TIMEOUT; 183 opts->privport = 0; 184 185 if (!params) 186 return 0; 187 188 tmp_options = kstrdup(params, GFP_KERNEL); 189 if (!tmp_options) { 190 p9_debug(P9_DEBUG_ERROR, 191 "failed to allocate copy of option string\n"); 192 return -ENOMEM; 193 } 194 options = tmp_options; 195 196 while ((p = strsep(&options, ",")) != NULL) { 197 int token; 198 int r; 199 if (!*p) 200 continue; 201 token = match_token(p, tokens, args); 202 if ((token != Opt_err) && (token != Opt_privport)) { 203 r = match_int(&args[0], &option); 204 if (r < 0) { 205 p9_debug(P9_DEBUG_ERROR, 206 "integer field, but no integer?\n"); 207 continue; 208 } 209 } 210 switch (token) { 211 case Opt_port: 212 opts->port = option; 213 break; 214 case Opt_sq_depth: 215 opts->sq_depth = option; 216 break; 217 case Opt_rq_depth: 218 opts->rq_depth = option; 219 break; 220 case Opt_timeout: 221 opts->timeout = option; 222 break; 223 case Opt_privport: 224 opts->privport = 1; 225 break; 226 default: 227 continue; 228 } 229 } 230 /* RQ must be at least as large as the SQ */ 231 opts->rq_depth = max(opts->rq_depth, opts->sq_depth); 232 kfree(tmp_options); 233 return 0; 234 } 235 236 static int 237 p9_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event) 238 { 239 struct p9_client *c = id->context; 240 struct p9_trans_rdma *rdma = c->trans; 241 switch (event->event) { 242 case RDMA_CM_EVENT_ADDR_RESOLVED: 243 BUG_ON(rdma->state != P9_RDMA_INIT); 244 rdma->state = P9_RDMA_ADDR_RESOLVED; 245 break; 246 247 case RDMA_CM_EVENT_ROUTE_RESOLVED: 248 BUG_ON(rdma->state != P9_RDMA_ADDR_RESOLVED); 249 rdma->state = P9_RDMA_ROUTE_RESOLVED; 250 break; 251 252 case RDMA_CM_EVENT_ESTABLISHED: 253 BUG_ON(rdma->state != P9_RDMA_ROUTE_RESOLVED); 254 rdma->state = P9_RDMA_CONNECTED; 255 break; 256 257 case RDMA_CM_EVENT_DISCONNECTED: 258 if (rdma) 259 rdma->state = P9_RDMA_CLOSED; 260 if (c) 261 c->status = Disconnected; 262 break; 263 264 case RDMA_CM_EVENT_TIMEWAIT_EXIT: 265 break; 266 267 case RDMA_CM_EVENT_ADDR_CHANGE: 268 case RDMA_CM_EVENT_ROUTE_ERROR: 269 case RDMA_CM_EVENT_DEVICE_REMOVAL: 270 case RDMA_CM_EVENT_MULTICAST_JOIN: 271 case RDMA_CM_EVENT_MULTICAST_ERROR: 272 case RDMA_CM_EVENT_REJECTED: 273 case RDMA_CM_EVENT_CONNECT_REQUEST: 274 case RDMA_CM_EVENT_CONNECT_RESPONSE: 275 case RDMA_CM_EVENT_CONNECT_ERROR: 276 case RDMA_CM_EVENT_ADDR_ERROR: 277 case RDMA_CM_EVENT_UNREACHABLE: 278 c->status = Disconnected; 279 rdma_disconnect(rdma->cm_id); 280 break; 281 default: 282 BUG(); 283 } 284 complete(&rdma->cm_done); 285 return 0; 286 } 287 288 static void 289 handle_recv(struct p9_client *client, struct p9_trans_rdma *rdma, 290 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len) 291 { 292 struct p9_req_t *req; 293 int err = 0; 294 int16_t tag; 295 296 req = NULL; 297 ib_dma_unmap_single(rdma->cm_id->device, c->busa, client->msize, 298 DMA_FROM_DEVICE); 299 300 if (status != IB_WC_SUCCESS) 301 goto err_out; 302 303 err = p9_parse_header(c->rc, NULL, NULL, &tag, 1); 304 if (err) 305 goto err_out; 306 307 req = p9_tag_lookup(client, tag); 308 if (!req) 309 goto err_out; 310 311 /* Check that we have not yet received a reply for this request. 312 */ 313 if (unlikely(req->rc)) { 314 pr_err("Duplicate reply for request %d", tag); 315 goto err_out; 316 } 317 318 req->rc = c->rc; 319 p9_client_cb(client, req, REQ_STATUS_RCVD); 320 321 return; 322 323 err_out: 324 p9_debug(P9_DEBUG_ERROR, "req %p err %d status %d\n", req, err, status); 325 rdma->state = P9_RDMA_FLUSHING; 326 client->status = Disconnected; 327 } 328 329 static void 330 handle_send(struct p9_client *client, struct p9_trans_rdma *rdma, 331 struct p9_rdma_context *c, enum ib_wc_status status, u32 byte_len) 332 { 333 ib_dma_unmap_single(rdma->cm_id->device, 334 c->busa, c->req->tc->size, 335 DMA_TO_DEVICE); 336 } 337 338 static void qp_event_handler(struct ib_event *event, void *context) 339 { 340 p9_debug(P9_DEBUG_ERROR, "QP event %d context %p\n", 341 event->event, context); 342 } 343 344 static void cq_comp_handler(struct ib_cq *cq, void *cq_context) 345 { 346 struct p9_client *client = cq_context; 347 struct p9_trans_rdma *rdma = client->trans; 348 int ret; 349 struct ib_wc wc; 350 351 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP); 352 while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) { 353 struct p9_rdma_context *c = (void *) (unsigned long) wc.wr_id; 354 355 switch (c->wc_op) { 356 case IB_WC_RECV: 357 handle_recv(client, rdma, c, wc.status, wc.byte_len); 358 up(&rdma->rq_sem); 359 break; 360 361 case IB_WC_SEND: 362 handle_send(client, rdma, c, wc.status, wc.byte_len); 363 up(&rdma->sq_sem); 364 break; 365 366 default: 367 pr_err("unexpected completion type, c->wc_op=%d, wc.opcode=%d, status=%d\n", 368 c->wc_op, wc.opcode, wc.status); 369 break; 370 } 371 kfree(c); 372 } 373 } 374 375 static void cq_event_handler(struct ib_event *e, void *v) 376 { 377 p9_debug(P9_DEBUG_ERROR, "CQ event %d context %p\n", e->event, v); 378 } 379 380 static void rdma_destroy_trans(struct p9_trans_rdma *rdma) 381 { 382 if (!rdma) 383 return; 384 385 if (rdma->dma_mr && !IS_ERR(rdma->dma_mr)) 386 ib_dereg_mr(rdma->dma_mr); 387 388 if (rdma->qp && !IS_ERR(rdma->qp)) 389 ib_destroy_qp(rdma->qp); 390 391 if (rdma->pd && !IS_ERR(rdma->pd)) 392 ib_dealloc_pd(rdma->pd); 393 394 if (rdma->cq && !IS_ERR(rdma->cq)) 395 ib_destroy_cq(rdma->cq); 396 397 if (rdma->cm_id && !IS_ERR(rdma->cm_id)) 398 rdma_destroy_id(rdma->cm_id); 399 400 kfree(rdma); 401 } 402 403 static int 404 post_recv(struct p9_client *client, struct p9_rdma_context *c) 405 { 406 struct p9_trans_rdma *rdma = client->trans; 407 struct ib_recv_wr wr, *bad_wr; 408 struct ib_sge sge; 409 410 c->busa = ib_dma_map_single(rdma->cm_id->device, 411 c->rc->sdata, client->msize, 412 DMA_FROM_DEVICE); 413 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) 414 goto error; 415 416 sge.addr = c->busa; 417 sge.length = client->msize; 418 sge.lkey = rdma->lkey; 419 420 wr.next = NULL; 421 c->wc_op = IB_WC_RECV; 422 wr.wr_id = (unsigned long) c; 423 wr.sg_list = &sge; 424 wr.num_sge = 1; 425 return ib_post_recv(rdma->qp, &wr, &bad_wr); 426 427 error: 428 p9_debug(P9_DEBUG_ERROR, "EIO\n"); 429 return -EIO; 430 } 431 432 static int rdma_request(struct p9_client *client, struct p9_req_t *req) 433 { 434 struct p9_trans_rdma *rdma = client->trans; 435 struct ib_send_wr wr, *bad_wr; 436 struct ib_sge sge; 437 int err = 0; 438 unsigned long flags; 439 struct p9_rdma_context *c = NULL; 440 struct p9_rdma_context *rpl_context = NULL; 441 442 /* When an error occurs between posting the recv and the send, 443 * there will be a receive context posted without a pending request. 444 * Since there is no way to "un-post" it, we remember it and skip 445 * post_recv() for the next request. 446 * So here, 447 * see if we are this `next request' and need to absorb an excess rc. 448 * If yes, then drop and free our own, and do not recv_post(). 449 **/ 450 if (unlikely(atomic_read(&rdma->excess_rc) > 0)) { 451 if ((atomic_sub_return(1, &rdma->excess_rc) >= 0)) { 452 /* Got one ! */ 453 kfree(req->rc); 454 req->rc = NULL; 455 goto dont_need_post_recv; 456 } else { 457 /* We raced and lost. */ 458 atomic_inc(&rdma->excess_rc); 459 } 460 } 461 462 /* Allocate an fcall for the reply */ 463 rpl_context = kmalloc(sizeof *rpl_context, GFP_NOFS); 464 if (!rpl_context) { 465 err = -ENOMEM; 466 goto recv_error; 467 } 468 rpl_context->rc = req->rc; 469 470 /* 471 * Post a receive buffer for this request. We need to ensure 472 * there is a reply buffer available for every outstanding 473 * request. A flushed request can result in no reply for an 474 * outstanding request, so we must keep a count to avoid 475 * overflowing the RQ. 476 */ 477 if (down_interruptible(&rdma->rq_sem)) { 478 err = -EINTR; 479 goto recv_error; 480 } 481 482 err = post_recv(client, rpl_context); 483 if (err) { 484 p9_debug(P9_DEBUG_FCALL, "POST RECV failed\n"); 485 goto recv_error; 486 } 487 /* remove posted receive buffer from request structure */ 488 req->rc = NULL; 489 490 dont_need_post_recv: 491 /* Post the request */ 492 c = kmalloc(sizeof *c, GFP_NOFS); 493 if (!c) { 494 err = -ENOMEM; 495 goto send_error; 496 } 497 c->req = req; 498 499 c->busa = ib_dma_map_single(rdma->cm_id->device, 500 c->req->tc->sdata, c->req->tc->size, 501 DMA_TO_DEVICE); 502 if (ib_dma_mapping_error(rdma->cm_id->device, c->busa)) { 503 err = -EIO; 504 goto send_error; 505 } 506 507 sge.addr = c->busa; 508 sge.length = c->req->tc->size; 509 sge.lkey = rdma->lkey; 510 511 wr.next = NULL; 512 c->wc_op = IB_WC_SEND; 513 wr.wr_id = (unsigned long) c; 514 wr.opcode = IB_WR_SEND; 515 wr.send_flags = IB_SEND_SIGNALED; 516 wr.sg_list = &sge; 517 wr.num_sge = 1; 518 519 if (down_interruptible(&rdma->sq_sem)) { 520 err = -EINTR; 521 goto send_error; 522 } 523 524 /* Mark request as `sent' *before* we actually send it, 525 * because doing if after could erase the REQ_STATUS_RCVD 526 * status in case of a very fast reply. 527 */ 528 req->status = REQ_STATUS_SENT; 529 err = ib_post_send(rdma->qp, &wr, &bad_wr); 530 if (err) 531 goto send_error; 532 533 /* Success */ 534 return 0; 535 536 /* Handle errors that happened during or while preparing the send: */ 537 send_error: 538 req->status = REQ_STATUS_ERROR; 539 kfree(c); 540 p9_debug(P9_DEBUG_ERROR, "Error %d in rdma_request()\n", err); 541 542 /* Ach. 543 * We did recv_post(), but not send. We have one recv_post in excess. 544 */ 545 atomic_inc(&rdma->excess_rc); 546 return err; 547 548 /* Handle errors that happened during or while preparing post_recv(): */ 549 recv_error: 550 kfree(rpl_context); 551 spin_lock_irqsave(&rdma->req_lock, flags); 552 if (rdma->state < P9_RDMA_CLOSING) { 553 rdma->state = P9_RDMA_CLOSING; 554 spin_unlock_irqrestore(&rdma->req_lock, flags); 555 rdma_disconnect(rdma->cm_id); 556 } else 557 spin_unlock_irqrestore(&rdma->req_lock, flags); 558 return err; 559 } 560 561 static void rdma_close(struct p9_client *client) 562 { 563 struct p9_trans_rdma *rdma; 564 565 if (!client) 566 return; 567 568 rdma = client->trans; 569 if (!rdma) 570 return; 571 572 client->status = Disconnected; 573 rdma_disconnect(rdma->cm_id); 574 rdma_destroy_trans(rdma); 575 } 576 577 /** 578 * alloc_rdma - Allocate and initialize the rdma transport structure 579 * @opts: Mount options structure 580 */ 581 static struct p9_trans_rdma *alloc_rdma(struct p9_rdma_opts *opts) 582 { 583 struct p9_trans_rdma *rdma; 584 585 rdma = kzalloc(sizeof(struct p9_trans_rdma), GFP_KERNEL); 586 if (!rdma) 587 return NULL; 588 589 rdma->sq_depth = opts->sq_depth; 590 rdma->rq_depth = opts->rq_depth; 591 rdma->timeout = opts->timeout; 592 spin_lock_init(&rdma->req_lock); 593 init_completion(&rdma->cm_done); 594 sema_init(&rdma->sq_sem, rdma->sq_depth); 595 sema_init(&rdma->rq_sem, rdma->rq_depth); 596 atomic_set(&rdma->excess_rc, 0); 597 598 return rdma; 599 } 600 601 static int rdma_cancel(struct p9_client *client, struct p9_req_t *req) 602 { 603 /* Nothing to do here. 604 * We will take care of it (if we have to) in rdma_cancelled() 605 */ 606 return 1; 607 } 608 609 /* A request has been fully flushed without a reply. 610 * That means we have posted one buffer in excess. 611 */ 612 static int rdma_cancelled(struct p9_client *client, struct p9_req_t *req) 613 { 614 struct p9_trans_rdma *rdma = client->trans; 615 atomic_inc(&rdma->excess_rc); 616 return 0; 617 } 618 619 static int p9_rdma_bind_privport(struct p9_trans_rdma *rdma) 620 { 621 struct sockaddr_in cl = { 622 .sin_family = AF_INET, 623 .sin_addr.s_addr = htonl(INADDR_ANY), 624 }; 625 int port, err = -EINVAL; 626 627 for (port = P9_DEF_MAX_RESVPORT; port >= P9_DEF_MIN_RESVPORT; port--) { 628 cl.sin_port = htons((ushort)port); 629 err = rdma_bind_addr(rdma->cm_id, (struct sockaddr *)&cl); 630 if (err != -EADDRINUSE) 631 break; 632 } 633 return err; 634 } 635 636 /** 637 * trans_create_rdma - Transport method for creating atransport instance 638 * @client: client instance 639 * @addr: IP address string 640 * @args: Mount options string 641 */ 642 static int 643 rdma_create_trans(struct p9_client *client, const char *addr, char *args) 644 { 645 int err; 646 struct p9_rdma_opts opts; 647 struct p9_trans_rdma *rdma; 648 struct rdma_conn_param conn_param; 649 struct ib_qp_init_attr qp_attr; 650 struct ib_device_attr devattr; 651 struct ib_cq_init_attr cq_attr = {}; 652 653 /* Parse the transport specific mount options */ 654 err = parse_opts(args, &opts); 655 if (err < 0) 656 return err; 657 658 /* Create and initialize the RDMA transport structure */ 659 rdma = alloc_rdma(&opts); 660 if (!rdma) 661 return -ENOMEM; 662 663 /* Create the RDMA CM ID */ 664 rdma->cm_id = rdma_create_id(p9_cm_event_handler, client, RDMA_PS_TCP, 665 IB_QPT_RC); 666 if (IS_ERR(rdma->cm_id)) 667 goto error; 668 669 /* Associate the client with the transport */ 670 client->trans = rdma; 671 672 /* Bind to a privileged port if we need to */ 673 if (opts.privport) { 674 err = p9_rdma_bind_privport(rdma); 675 if (err < 0) { 676 pr_err("%s (%d): problem binding to privport: %d\n", 677 __func__, task_pid_nr(current), -err); 678 goto error; 679 } 680 } 681 682 /* Resolve the server's address */ 683 rdma->addr.sin_family = AF_INET; 684 rdma->addr.sin_addr.s_addr = in_aton(addr); 685 rdma->addr.sin_port = htons(opts.port); 686 err = rdma_resolve_addr(rdma->cm_id, NULL, 687 (struct sockaddr *)&rdma->addr, 688 rdma->timeout); 689 if (err) 690 goto error; 691 err = wait_for_completion_interruptible(&rdma->cm_done); 692 if (err || (rdma->state != P9_RDMA_ADDR_RESOLVED)) 693 goto error; 694 695 /* Resolve the route to the server */ 696 err = rdma_resolve_route(rdma->cm_id, rdma->timeout); 697 if (err) 698 goto error; 699 err = wait_for_completion_interruptible(&rdma->cm_done); 700 if (err || (rdma->state != P9_RDMA_ROUTE_RESOLVED)) 701 goto error; 702 703 /* Query the device attributes */ 704 err = ib_query_device(rdma->cm_id->device, &devattr); 705 if (err) 706 goto error; 707 708 /* Create the Completion Queue */ 709 cq_attr.cqe = opts.sq_depth + opts.rq_depth + 1; 710 rdma->cq = ib_create_cq(rdma->cm_id->device, cq_comp_handler, 711 cq_event_handler, client, 712 &cq_attr); 713 if (IS_ERR(rdma->cq)) 714 goto error; 715 ib_req_notify_cq(rdma->cq, IB_CQ_NEXT_COMP); 716 717 /* Create the Protection Domain */ 718 rdma->pd = ib_alloc_pd(rdma->cm_id->device); 719 if (IS_ERR(rdma->pd)) 720 goto error; 721 722 /* Cache the DMA lkey in the transport */ 723 rdma->dma_mr = NULL; 724 if (devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY) 725 rdma->lkey = rdma->cm_id->device->local_dma_lkey; 726 else { 727 rdma->dma_mr = ib_get_dma_mr(rdma->pd, IB_ACCESS_LOCAL_WRITE); 728 if (IS_ERR(rdma->dma_mr)) 729 goto error; 730 rdma->lkey = rdma->dma_mr->lkey; 731 } 732 733 /* Create the Queue Pair */ 734 memset(&qp_attr, 0, sizeof qp_attr); 735 qp_attr.event_handler = qp_event_handler; 736 qp_attr.qp_context = client; 737 qp_attr.cap.max_send_wr = opts.sq_depth; 738 qp_attr.cap.max_recv_wr = opts.rq_depth; 739 qp_attr.cap.max_send_sge = P9_RDMA_SEND_SGE; 740 qp_attr.cap.max_recv_sge = P9_RDMA_RECV_SGE; 741 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR; 742 qp_attr.qp_type = IB_QPT_RC; 743 qp_attr.send_cq = rdma->cq; 744 qp_attr.recv_cq = rdma->cq; 745 err = rdma_create_qp(rdma->cm_id, rdma->pd, &qp_attr); 746 if (err) 747 goto error; 748 rdma->qp = rdma->cm_id->qp; 749 750 /* Request a connection */ 751 memset(&conn_param, 0, sizeof(conn_param)); 752 conn_param.private_data = NULL; 753 conn_param.private_data_len = 0; 754 conn_param.responder_resources = P9_RDMA_IRD; 755 conn_param.initiator_depth = P9_RDMA_ORD; 756 err = rdma_connect(rdma->cm_id, &conn_param); 757 if (err) 758 goto error; 759 err = wait_for_completion_interruptible(&rdma->cm_done); 760 if (err || (rdma->state != P9_RDMA_CONNECTED)) 761 goto error; 762 763 client->status = Connected; 764 765 return 0; 766 767 error: 768 rdma_destroy_trans(rdma); 769 return -ENOTCONN; 770 } 771 772 static struct p9_trans_module p9_rdma_trans = { 773 .name = "rdma", 774 .maxsize = P9_RDMA_MAXSIZE, 775 .def = 0, 776 .owner = THIS_MODULE, 777 .create = rdma_create_trans, 778 .close = rdma_close, 779 .request = rdma_request, 780 .cancel = rdma_cancel, 781 .cancelled = rdma_cancelled, 782 }; 783 784 /** 785 * p9_trans_rdma_init - Register the 9P RDMA transport driver 786 */ 787 static int __init p9_trans_rdma_init(void) 788 { 789 v9fs_register_trans(&p9_rdma_trans); 790 return 0; 791 } 792 793 static void __exit p9_trans_rdma_exit(void) 794 { 795 v9fs_unregister_trans(&p9_rdma_trans); 796 } 797 798 module_init(p9_trans_rdma_init); 799 module_exit(p9_trans_rdma_exit); 800 801 MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>"); 802 MODULE_DESCRIPTION("RDMA Transport for 9P"); 803 MODULE_LICENSE("Dual BSD/GPL"); 804