net/sunrpc/xprtrdma/verbs.c

   1 /*
   2  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the BSD-type
   8  * license below:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  *      Redistributions of source code must retain the above copyright
  15  *      notice, this list of conditions and the following disclaimer.
  16  *
  17  *      Redistributions in binary form must reproduce the above
  18  *      copyright notice, this list of conditions and the following
  19  *      disclaimer in the documentation and/or other materials provided
  20  *      with the distribution.
  21  *
  22  *      Neither the name of the Network Appliance, Inc. nor the names of
  23  *      its contributors may be used to endorse or promote products
  24  *      derived from this software without specific prior written
  25  *      permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  */
  39
  40 /*
  41  * verbs.c
  42  *
  43  * Encapsulates the major functions managing:
  44  *  o adapters
  45  *  o endpoints
  46  *  o connections
  47  *  o buffer memory
  48  */
  49
  50 #include <linux/interrupt.h>
  51 #include <linux/slab.h>
  52 #include <linux/prefetch.h>
  53 #include <linux/sunrpc/addr.h>
  54 #include <asm/bitops.h>
  55 #include <linux/module.h> /* try_module_get()/module_put() */
  56
  57 #include "xprt_rdma.h"
  58
  59 /*
  60  * Globals/Macros
  61  */
  62
  63 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  64 # define RPCDBG_FACILITY        RPCDBG_TRANS
  65 #endif
  66
  67 /*
  68  * internal functions
  69  */
  70
  71 static struct workqueue_struct *rpcrdma_receive_wq;
  72
  73 int
  74 rpcrdma_alloc_wq(void)
  75 {
  76         struct workqueue_struct *recv_wq;
  77
  78         recv_wq = alloc_workqueue("xprtrdma_receive",
  79                                   WQ_MEM_RECLAIM | WQ_UNBOUND | WQ_HIGHPRI,
  80                                   0);
  81         if (!recv_wq)
  82                 return -ENOMEM;
  83
  84         rpcrdma_receive_wq = recv_wq;
  85         return 0;
  86 }
  87
  88 void
  89 rpcrdma_destroy_wq(void)
  90 {
  91         struct workqueue_struct *wq;
  92
  93         if (rpcrdma_receive_wq) {
  94                 wq = rpcrdma_receive_wq;
  95                 rpcrdma_receive_wq = NULL;
  96                 destroy_workqueue(wq);
  97         }
  98 }
  99
 100 static void
 101 rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
 102 {
 103         struct rpcrdma_ep *ep = context;
 104
 105         pr_err("RPC:       %s: %s on device %s ep %p\n",
 106                __func__, ib_event_msg(event->event),
 107                 event->device->name, context);
 108         if (ep->rep_connected == 1) {
 109                 ep->rep_connected = -EIO;
 110                 rpcrdma_conn_func(ep);
 111                 wake_up_all(&ep->rep_connect_wait);
 112         }
 113 }
 114
 115 static void
 116 rpcrdma_cq_async_error_upcall(struct ib_event *event, void *context)
 117 {
 118         struct rpcrdma_ep *ep = context;
 119
 120         pr_err("RPC:       %s: %s on device %s ep %p\n",
 121                __func__, ib_event_msg(event->event),
 122                 event->device->name, context);
 123         if (ep->rep_connected == 1) {
 124                 ep->rep_connected = -EIO;
 125                 rpcrdma_conn_func(ep);
 126                 wake_up_all(&ep->rep_connect_wait);
 127         }
 128 }
 129
 130 static void
 131 rpcrdma_sendcq_process_wc(struct ib_wc *wc)
 132 {
 133         /* WARNING: Only wr_id and status are reliable at this point */
 134         if (wc->wr_id == RPCRDMA_IGNORE_COMPLETION) {
 135                 if (wc->status != IB_WC_SUCCESS &&
 136                     wc->status != IB_WC_WR_FLUSH_ERR)
 137                         pr_err("RPC:       %s: SEND: %s\n",
 138                                __func__, ib_wc_status_msg(wc->status));
 139         } else {
 140                 struct rpcrdma_mw *r;
 141
 142                 r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
 143                 r->mw_sendcompletion(wc);
 144         }
 145 }
 146
 147 /* The common case is a single send completion is waiting. By
 148  * passing two WC entries to ib_poll_cq, a return code of 1
 149  * means there is exactly one WC waiting and no more. We don't
 150  * have to invoke ib_poll_cq again to know that the CQ has been
 151  * properly drained.
 152  */
 153 static void
 154 rpcrdma_sendcq_poll(struct ib_cq *cq)
 155 {
 156         struct ib_wc *pos, wcs[2];
 157         int count, rc;
 158
 159         do {
 160                 pos = wcs;
 161
 162                 rc = ib_poll_cq(cq, ARRAY_SIZE(wcs), pos);
 163                 if (rc < 0)
 164                         break;
 165
 166                 count = rc;
 167                 while (count-- > 0)
 168                         rpcrdma_sendcq_process_wc(pos++);
 169         } while (rc == ARRAY_SIZE(wcs));
 170         return;
 171 }
 172
 173 /* Handle provider send completion upcalls.
 174  */
 175 static void
 176 rpcrdma_sendcq_upcall(struct ib_cq *cq, void *cq_context)
 177 {
 178         do {
 179                 rpcrdma_sendcq_poll(cq);
 180         } while (ib_req_notify_cq(cq, IB_CQ_NEXT_COMP |
 181                                   IB_CQ_REPORT_MISSED_EVENTS) > 0);
 182 }
 183
 184 static void
 185 rpcrdma_receive_worker(struct work_struct *work)
 186 {
 187         struct rpcrdma_rep *rep =
 188                         container_of(work, struct rpcrdma_rep, rr_work);
 189
 190         rpcrdma_reply_handler(rep);
 191 }
 192
 193 static void
 194 rpcrdma_recvcq_process_wc(struct ib_wc *wc)
 195 {
 196         struct rpcrdma_rep *rep =
 197                         (struct rpcrdma_rep *)(unsigned long)wc->wr_id;
 198
 199         /* WARNING: Only wr_id and status are reliable at this point */
 200         if (wc->status != IB_WC_SUCCESS)
 201                 goto out_fail;
 202
 203         /* status == SUCCESS means all fields in wc are trustworthy */
 204         if (wc->opcode != IB_WC_RECV)
 205                 return;
 206
 207         dprintk("RPC:       %s: rep %p opcode 'recv', length %u: success\n",
 208                 __func__, rep, wc->byte_len);
 209
 210         rep->rr_len = wc->byte_len;
 211         ib_dma_sync_single_for_cpu(rep->rr_device,
 212                                    rdmab_addr(rep->rr_rdmabuf),
 213                                    rep->rr_len, DMA_FROM_DEVICE);
 214         prefetch(rdmab_to_msg(rep->rr_rdmabuf));
 215
 216 out_schedule:
 217         queue_work(rpcrdma_receive_wq, &rep->rr_work);
 218         return;
 219
 220 out_fail:
 221         if (wc->status != IB_WC_WR_FLUSH_ERR)
 222                 pr_err("RPC:       %s: rep %p: %s\n",
 223                        __func__, rep, ib_wc_status_msg(wc->status));
 224         rep->rr_len = RPCRDMA_BAD_LEN;
 225         goto out_schedule;
 226 }
 227
 228 /* The wc array is on stack: automatic memory is always CPU-local.
 229  *
 230  * struct ib_wc is 64 bytes, making the poll array potentially
 231  * large. But this is at the bottom of the call chain. Further
 232  * substantial work is done in another thread.
 233  */
 234 static void
 235 rpcrdma_recvcq_poll(struct ib_cq *cq)
 236 {
 237         struct ib_wc *pos, wcs[4];
 238         int count, rc;
 239
 240         do {
 241                 pos = wcs;
 242
 243                 rc = ib_poll_cq(cq, ARRAY_SIZE(wcs), pos);
 244                 if (rc < 0)
 245                         break;
 246
 247                 count = rc;
 248                 while (count-- > 0)
 249                         rpcrdma_recvcq_process_wc(pos++);
 250         } while (rc == ARRAY_SIZE(wcs));
 251 }
 252
 253 /* Handle provider receive completion upcalls.
 254  */
 255 static void
 256 rpcrdma_recvcq_upcall(struct ib_cq *cq, void *cq_context)
 257 {
 258         do {
 259                 rpcrdma_recvcq_poll(cq);
 260         } while (ib_req_notify_cq(cq, IB_CQ_NEXT_COMP |
 261                                   IB_CQ_REPORT_MISSED_EVENTS) > 0);
 262 }
 263
 264 static void
 265 rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
 266 {
 267         struct ib_wc wc;
 268
 269         while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
 270                 rpcrdma_recvcq_process_wc(&wc);
 271         while (ib_poll_cq(ep->rep_attr.send_cq, 1, &wc) > 0)
 272                 rpcrdma_sendcq_process_wc(&wc);
 273 }
 274
 275 static int
 276 rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
 277 {
 278         struct rpcrdma_xprt *xprt = id->context;
 279         struct rpcrdma_ia *ia = &xprt->rx_ia;
 280         struct rpcrdma_ep *ep = &xprt->rx_ep;
 281 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 282         struct sockaddr *sap = (struct sockaddr *)&ep->rep_remote_addr;
 283 #endif
 284         struct ib_qp_attr *attr = &ia->ri_qp_attr;
 285         struct ib_qp_init_attr *iattr = &ia->ri_qp_init_attr;
 286         int connstate = 0;
 287
 288         switch (event->event) {
 289         case RDMA_CM_EVENT_ADDR_RESOLVED:
 290         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 291                 ia->ri_async_rc = 0;
 292                 complete(&ia->ri_done);
 293                 break;
 294         case RDMA_CM_EVENT_ADDR_ERROR:
 295                 ia->ri_async_rc = -EHOSTUNREACH;
 296                 dprintk("RPC:       %s: CM address resolution error, ep 0x%p\n",
 297                         __func__, ep);
 298                 complete(&ia->ri_done);
 299                 break;
 300         case RDMA_CM_EVENT_ROUTE_ERROR:
 301                 ia->ri_async_rc = -ENETUNREACH;
 302                 dprintk("RPC:       %s: CM route resolution error, ep 0x%p\n",
 303                         __func__, ep);
 304                 complete(&ia->ri_done);
 305                 break;
 306         case RDMA_CM_EVENT_ESTABLISHED:
 307                 connstate = 1;
 308                 ib_query_qp(ia->ri_id->qp, attr,
 309                             IB_QP_MAX_QP_RD_ATOMIC | IB_QP_MAX_DEST_RD_ATOMIC,
 310                             iattr);
 311                 dprintk("RPC:       %s: %d responder resources"
 312                         " (%d initiator)\n",
 313                         __func__, attr->max_dest_rd_atomic,
 314                         attr->max_rd_atomic);
 315                 goto connected;
 316         case RDMA_CM_EVENT_CONNECT_ERROR:
 317                 connstate = -ENOTCONN;
 318                 goto connected;
 319         case RDMA_CM_EVENT_UNREACHABLE:
 320                 connstate = -ENETDOWN;
 321                 goto connected;
 322         case RDMA_CM_EVENT_REJECTED:
 323                 connstate = -ECONNREFUSED;
 324                 goto connected;
 325         case RDMA_CM_EVENT_DISCONNECTED:
 326                 connstate = -ECONNABORTED;
 327                 goto connected;
 328         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 329                 connstate = -ENODEV;
 330 connected:
 331                 dprintk("RPC:       %s: %sconnected\n",
 332                                         __func__, connstate > 0 ? "" : "dis");
 333                 ep->rep_connected = connstate;
 334                 rpcrdma_conn_func(ep);
 335                 wake_up_all(&ep->rep_connect_wait);
 336                 /*FALLTHROUGH*/
 337         default:
 338                 dprintk("RPC:       %s: %pIS:%u (ep 0x%p): %s\n",
 339                         __func__, sap, rpc_get_port(sap), ep,
 340                         rdma_event_msg(event->event));
 341                 break;
 342         }
 343
 344 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 345         if (connstate == 1) {
 346                 int ird = attr->max_dest_rd_atomic;
 347                 int tird = ep->rep_remote_cma.responder_resources;
 348
 349                 pr_info("rpcrdma: connection to %pIS:%u on %s, memreg '%s', %d credits, %d responders%s\n",
 350                         sap, rpc_get_port(sap),
 351                         ia->ri_device->name,
 352                         ia->ri_ops->ro_displayname,
 353                         xprt->rx_buf.rb_max_requests,
 354                         ird, ird < 4 && ird < tird / 2 ? " (low!)" : "");
 355         } else if (connstate < 0) {
 356                 pr_info("rpcrdma: connection to %pIS:%u closed (%d)\n",
 357                         sap, rpc_get_port(sap), connstate);
 358         }
 359 #endif
 360
 361         return 0;
 362 }
 363
 364 static void rpcrdma_destroy_id(struct rdma_cm_id *id)
 365 {
 366         if (id) {
 367                 module_put(id->device->owner);
 368                 rdma_destroy_id(id);
 369         }
 370 }
 371
 372 static struct rdma_cm_id *
 373 rpcrdma_create_id(struct rpcrdma_xprt *xprt,
 374                         struct rpcrdma_ia *ia, struct sockaddr *addr)
 375 {
 376         struct rdma_cm_id *id;
 377         int rc;
 378
 379         init_completion(&ia->ri_done);
 380
 381         id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
 382                             IB_QPT_RC);
 383         if (IS_ERR(id)) {
 384                 rc = PTR_ERR(id);
 385                 dprintk("RPC:       %s: rdma_create_id() failed %i\n",
 386                         __func__, rc);
 387                 return id;
 388         }
 389
 390         ia->ri_async_rc = -ETIMEDOUT;
 391         rc = rdma_resolve_addr(id, NULL, addr, RDMA_RESOLVE_TIMEOUT);
 392         if (rc) {
 393                 dprintk("RPC:       %s: rdma_resolve_addr() failed %i\n",
 394                         __func__, rc);
 395                 goto out;
 396         }
 397         wait_for_completion_interruptible_timeout(&ia->ri_done,
 398                                 msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
 399
 400         /* FIXME:
 401          * Until xprtrdma supports DEVICE_REMOVAL, the provider must
 402          * be pinned while there are active NFS/RDMA mounts to prevent
 403          * hangs and crashes at umount time.
 404          */
 405         if (!ia->ri_async_rc && !try_module_get(id->device->owner)) {
 406                 dprintk("RPC:       %s: Failed to get device module\n",
 407                         __func__);
 408                 ia->ri_async_rc = -ENODEV;
 409         }
 410         rc = ia->ri_async_rc;
 411         if (rc)
 412                 goto out;
 413
 414         ia->ri_async_rc = -ETIMEDOUT;
 415         rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
 416         if (rc) {
 417                 dprintk("RPC:       %s: rdma_resolve_route() failed %i\n",
 418                         __func__, rc);
 419                 goto put;
 420         }
 421         wait_for_completion_interruptible_timeout(&ia->ri_done,
 422                                 msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
 423         rc = ia->ri_async_rc;
 424         if (rc)
 425                 goto put;
 426
 427         return id;
 428 put:
 429         module_put(id->device->owner);
 430 out:
 431         rdma_destroy_id(id);
 432         return ERR_PTR(rc);
 433 }
 434
 435 /*
 436  * Drain any cq, prior to teardown.
 437  */
 438 static void
 439 rpcrdma_clean_cq(struct ib_cq *cq)
 440 {
 441         struct ib_wc wc;
 442         int count = 0;
 443
 444         while (1 == ib_poll_cq(cq, 1, &wc))
 445                 ++count;
 446
 447         if (count)
 448                 dprintk("RPC:       %s: flushed %d events (last 0x%x)\n",
 449                         __func__, count, wc.opcode);
 450 }
 451
 452 /*
 453  * Exported functions.
 454  */
 455
 456 /*
 457  * Open and initialize an Interface Adapter.
 458  *  o initializes fields of struct rpcrdma_ia, including
 459  *    interface and provider attributes and protection zone.
 460  */
 461 int
 462 rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 463 {
 464         struct rpcrdma_ia *ia = &xprt->rx_ia;
 465         int rc;
 466
 467         ia->ri_dma_mr = NULL;
 468
 469         ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
 470         if (IS_ERR(ia->ri_id)) {
 471                 rc = PTR_ERR(ia->ri_id);
 472                 goto out1;
 473         }
 474         ia->ri_device = ia->ri_id->device;
 475
 476         ia->ri_pd = ib_alloc_pd(ia->ri_device);
 477         if (IS_ERR(ia->ri_pd)) {
 478                 rc = PTR_ERR(ia->ri_pd);
 479                 dprintk("RPC:       %s: ib_alloc_pd() failed %i\n",
 480                         __func__, rc);
 481                 goto out2;
 482         }
 483
 484         if (memreg == RPCRDMA_FRMR) {
 485                 if (!(ia->ri_device->attrs.device_cap_flags &
 486                                 IB_DEVICE_MEM_MGT_EXTENSIONS) ||
 487                     (ia->ri_device->attrs.max_fast_reg_page_list_len == 0)) {
 488                         dprintk("RPC:       %s: FRMR registration "
 489                                 "not supported by HCA\n", __func__);
 490                         memreg = RPCRDMA_MTHCAFMR;
 491                 }
 492         }
 493         if (memreg == RPCRDMA_MTHCAFMR) {
 494                 if (!ia->ri_device->alloc_fmr) {
 495                         dprintk("RPC:       %s: MTHCAFMR registration "
 496                                 "not supported by HCA\n", __func__);
 497                         rc = -EINVAL;
 498                         goto out3;
 499                 }
 500         }
 501
 502         switch (memreg) {
 503         case RPCRDMA_FRMR:
 504                 ia->ri_ops = &rpcrdma_frwr_memreg_ops;
 505                 break;
 506         case RPCRDMA_ALLPHYSICAL:
 507                 ia->ri_ops = &rpcrdma_physical_memreg_ops;
 508                 break;
 509         case RPCRDMA_MTHCAFMR:
 510                 ia->ri_ops = &rpcrdma_fmr_memreg_ops;
 511                 break;
 512         default:
 513                 printk(KERN_ERR "RPC: Unsupported memory "
 514                                 "registration mode: %d\n", memreg);
 515                 rc = -ENOMEM;
 516                 goto out3;
 517         }
 518         dprintk("RPC:       %s: memory registration strategy is '%s'\n",
 519                 __func__, ia->ri_ops->ro_displayname);
 520
 521         rwlock_init(&ia->ri_qplock);
 522         return 0;
 523
 524 out3:
 525         ib_dealloc_pd(ia->ri_pd);
 526         ia->ri_pd = NULL;
 527 out2:
 528         rpcrdma_destroy_id(ia->ri_id);
 529         ia->ri_id = NULL;
 530 out1:
 531         return rc;
 532 }
 533
 534 /*
 535  * Clean up/close an IA.
 536  *   o if event handles and PD have been initialized, free them.
 537  *   o close the IA
 538  */
 539 void
 540 rpcrdma_ia_close(struct rpcrdma_ia *ia)
 541 {
 542         dprintk("RPC:       %s: entering\n", __func__);
 543         if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
 544                 if (ia->ri_id->qp)
 545                         rdma_destroy_qp(ia->ri_id);
 546                 rpcrdma_destroy_id(ia->ri_id);
 547                 ia->ri_id = NULL;
 548         }
 549
 550         /* If the pd is still busy, xprtrdma missed freeing a resource */
 551         if (ia->ri_pd && !IS_ERR(ia->ri_pd))
 552                 ib_dealloc_pd(ia->ri_pd);
 553 }
 554
 555 /*
 556  * Create unconnected endpoint.
 557  */
 558 int
 559 rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 560                                 struct rpcrdma_create_data_internal *cdata)
 561 {
 562         struct ib_cq *sendcq, *recvcq;
 563         struct ib_cq_init_attr cq_attr = {};
 564         unsigned int max_qp_wr;
 565         int rc, err;
 566
 567         if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_IOVS) {
 568                 dprintk("RPC:       %s: insufficient sge's available\n",
 569                         __func__);
 570                 return -ENOMEM;
 571         }
 572
 573         if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
 574                 dprintk("RPC:       %s: insufficient wqe's available\n",
 575                         __func__);
 576                 return -ENOMEM;
 577         }
 578         max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS;
 579
 580         /* check provider's send/recv wr limits */
 581         if (cdata->max_requests > max_qp_wr)
 582                 cdata->max_requests = max_qp_wr;
 583
 584         ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
 585         ep->rep_attr.qp_context = ep;
 586         ep->rep_attr.srq = NULL;
 587         ep->rep_attr.cap.max_send_wr = cdata->max_requests;
 588         ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
 589         rc = ia->ri_ops->ro_open(ia, ep, cdata);
 590         if (rc)
 591                 return rc;
 592         ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
 593         ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
 594         ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_IOVS;
 595         ep->rep_attr.cap.max_recv_sge = 1;
 596         ep->rep_attr.cap.max_inline_data = 0;
 597         ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 598         ep->rep_attr.qp_type = IB_QPT_RC;
 599         ep->rep_attr.port_num = ~0;
 600
 601         dprintk("RPC:       %s: requested max: dtos: send %d recv %d; "
 602                 "iovs: send %d recv %d\n",
 603                 __func__,
 604                 ep->rep_attr.cap.max_send_wr,
 605                 ep->rep_attr.cap.max_recv_wr,
 606                 ep->rep_attr.cap.max_send_sge,
 607                 ep->rep_attr.cap.max_recv_sge);
 608
 609         /* set trigger for requesting send completion */
 610         ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
 611         if (ep->rep_cqinit <= 2)
 612                 ep->rep_cqinit = 0;     /* always signal? */
 613         INIT_CQCOUNT(ep);
 614         init_waitqueue_head(&ep->rep_connect_wait);
 615         INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
 616
 617         cq_attr.cqe = ep->rep_attr.cap.max_send_wr + 1;
 618         sendcq = ib_create_cq(ia->ri_device, rpcrdma_sendcq_upcall,
 619                               rpcrdma_cq_async_error_upcall, NULL, &cq_attr);
 620         if (IS_ERR(sendcq)) {
 621                 rc = PTR_ERR(sendcq);
 622                 dprintk("RPC:       %s: failed to create send CQ: %i\n",
 623                         __func__, rc);
 624                 goto out1;
 625         }
 626
 627         rc = ib_req_notify_cq(sendcq, IB_CQ_NEXT_COMP);
 628         if (rc) {
 629                 dprintk("RPC:       %s: ib_req_notify_cq failed: %i\n",
 630                         __func__, rc);
 631                 goto out2;
 632         }
 633
 634         cq_attr.cqe = ep->rep_attr.cap.max_recv_wr + 1;
 635         recvcq = ib_create_cq(ia->ri_device, rpcrdma_recvcq_upcall,
 636                               rpcrdma_cq_async_error_upcall, NULL, &cq_attr);
 637         if (IS_ERR(recvcq)) {
 638                 rc = PTR_ERR(recvcq);
 639                 dprintk("RPC:       %s: failed to create recv CQ: %i\n",
 640                         __func__, rc);
 641                 goto out2;
 642         }
 643
 644         rc = ib_req_notify_cq(recvcq, IB_CQ_NEXT_COMP);
 645         if (rc) {
 646                 dprintk("RPC:       %s: ib_req_notify_cq failed: %i\n",
 647                         __func__, rc);
 648                 ib_destroy_cq(recvcq);
 649                 goto out2;
 650         }
 651
 652         ep->rep_attr.send_cq = sendcq;
 653         ep->rep_attr.recv_cq = recvcq;
 654
 655         /* Initialize cma parameters */
 656
 657         /* RPC/RDMA does not use private data */
 658         ep->rep_remote_cma.private_data = NULL;
 659         ep->rep_remote_cma.private_data_len = 0;
 660
 661         /* Client offers RDMA Read but does not initiate */
 662         ep->rep_remote_cma.initiator_depth = 0;
 663         if (ia->ri_device->attrs.max_qp_rd_atom > 32)   /* arbitrary but <= 255 */
 664                 ep->rep_remote_cma.responder_resources = 32;
 665         else
 666                 ep->rep_remote_cma.responder_resources =
 667                                                 ia->ri_device->attrs.max_qp_rd_atom;
 668
 669         ep->rep_remote_cma.retry_count = 7;
 670         ep->rep_remote_cma.flow_control = 0;
 671         ep->rep_remote_cma.rnr_retry_count = 0;
 672
 673         return 0;
 674
 675 out2:
 676         err = ib_destroy_cq(sendcq);
 677         if (err)
 678                 dprintk("RPC:       %s: ib_destroy_cq returned %i\n",
 679                         __func__, err);
 680 out1:
 681         if (ia->ri_dma_mr)
 682                 ib_dereg_mr(ia->ri_dma_mr);
 683         return rc;
 684 }
 685
 686 /*
 687  * rpcrdma_ep_destroy
 688  *
 689  * Disconnect and destroy endpoint. After this, the only
 690  * valid operations on the ep are to free it (if dynamically
 691  * allocated) or re-create it.
 692  */
 693 void
 694 rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 695 {
 696         int rc;
 697
 698         dprintk("RPC:       %s: entering, connected is %d\n",
 699                 __func__, ep->rep_connected);
 700
 701         cancel_delayed_work_sync(&ep->rep_connect_worker);
 702
 703         if (ia->ri_id->qp)
 704                 rpcrdma_ep_disconnect(ep, ia);
 705
 706         rpcrdma_clean_cq(ep->rep_attr.recv_cq);
 707         rpcrdma_clean_cq(ep->rep_attr.send_cq);
 708
 709         if (ia->ri_id->qp) {
 710                 rdma_destroy_qp(ia->ri_id);
 711                 ia->ri_id->qp = NULL;
 712         }
 713
 714         rc = ib_destroy_cq(ep->rep_attr.recv_cq);
 715         if (rc)
 716                 dprintk("RPC:       %s: ib_destroy_cq returned %i\n",
 717                         __func__, rc);
 718
 719         rc = ib_destroy_cq(ep->rep_attr.send_cq);
 720         if (rc)
 721                 dprintk("RPC:       %s: ib_destroy_cq returned %i\n",
 722                         __func__, rc);
 723
 724         if (ia->ri_dma_mr) {
 725                 rc = ib_dereg_mr(ia->ri_dma_mr);
 726                 dprintk("RPC:       %s: ib_dereg_mr returned %i\n",
 727                         __func__, rc);
 728         }
 729 }
 730
 731 /*
 732  * Connect unconnected endpoint.
 733  */
 734 int
 735 rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 736 {
 737         struct rdma_cm_id *id, *old;
 738         int rc = 0;
 739         int retry_count = 0;
 740
 741         if (ep->rep_connected != 0) {
 742                 struct rpcrdma_xprt *xprt;
 743 retry:
 744                 dprintk("RPC:       %s: reconnecting...\n", __func__);
 745
 746                 rpcrdma_ep_disconnect(ep, ia);
 747                 rpcrdma_flush_cqs(ep);
 748
 749                 xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
 750                 id = rpcrdma_create_id(xprt, ia,
 751                                 (struct sockaddr *)&xprt->rx_data.addr);
 752                 if (IS_ERR(id)) {
 753                         rc = -EHOSTUNREACH;
 754                         goto out;
 755                 }
 756                 /* TEMP TEMP TEMP - fail if new device:
 757                  * Deregister/remarshal *all* requests!
 758                  * Close and recreate adapter, pd, etc!
 759                  * Re-determine all attributes still sane!
 760                  * More stuff I haven't thought of!
 761                  * Rrrgh!
 762                  */
 763                 if (ia->ri_device != id->device) {
 764                         printk("RPC:       %s: can't reconnect on "
 765                                 "different device!\n", __func__);
 766                         rpcrdma_destroy_id(id);
 767                         rc = -ENETUNREACH;
 768                         goto out;
 769                 }
 770                 /* END TEMP */
 771                 rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
 772                 if (rc) {
 773                         dprintk("RPC:       %s: rdma_create_qp failed %i\n",
 774                                 __func__, rc);
 775                         rpcrdma_destroy_id(id);
 776                         rc = -ENETUNREACH;
 777                         goto out;
 778                 }
 779
 780                 write_lock(&ia->ri_qplock);
 781                 old = ia->ri_id;
 782                 ia->ri_id = id;
 783                 write_unlock(&ia->ri_qplock);
 784
 785                 rdma_destroy_qp(old);
 786                 rpcrdma_destroy_id(old);
 787         } else {
 788                 dprintk("RPC:       %s: connecting...\n", __func__);
 789                 rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
 790                 if (rc) {
 791                         dprintk("RPC:       %s: rdma_create_qp failed %i\n",
 792                                 __func__, rc);
 793                         /* do not update ep->rep_connected */
 794                         return -ENETUNREACH;
 795                 }
 796         }
 797
 798         ep->rep_connected = 0;
 799
 800         rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
 801         if (rc) {
 802                 dprintk("RPC:       %s: rdma_connect() failed with %i\n",
 803                                 __func__, rc);
 804                 goto out;
 805         }
 806
 807         wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
 808
 809         /*
 810          * Check state. A non-peer reject indicates no listener
 811          * (ECONNREFUSED), which may be a transient state. All
 812          * others indicate a transport condition which has already
 813          * undergone a best-effort.
 814          */
 815         if (ep->rep_connected == -ECONNREFUSED &&
 816             ++retry_count <= RDMA_CONNECT_RETRY_MAX) {
 817                 dprintk("RPC:       %s: non-peer_reject, retry\n", __func__);
 818                 goto retry;
 819         }
 820         if (ep->rep_connected <= 0) {
 821                 /* Sometimes, the only way to reliably connect to remote
 822                  * CMs is to use same nonzero values for ORD and IRD. */
 823                 if (retry_count++ <= RDMA_CONNECT_RETRY_MAX + 1 &&
 824                     (ep->rep_remote_cma.responder_resources == 0 ||
 825                      ep->rep_remote_cma.initiator_depth !=
 826                                 ep->rep_remote_cma.responder_resources)) {
 827                         if (ep->rep_remote_cma.responder_resources == 0)
 828                                 ep->rep_remote_cma.responder_resources = 1;
 829                         ep->rep_remote_cma.initiator_depth =
 830                                 ep->rep_remote_cma.responder_resources;
 831                         goto retry;
 832                 }
 833                 rc = ep->rep_connected;
 834         } else {
 835                 struct rpcrdma_xprt *r_xprt;
 836                 unsigned int extras;
 837
 838                 dprintk("RPC:       %s: connected\n", __func__);
 839
 840                 r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
 841                 extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
 842
 843                 if (extras) {
 844                         rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
 845                         if (rc) {
 846                                 pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
 847                                         __func__, rc);
 848                                 rc = 0;
 849                         }
 850                 }
 851         }
 852
 853 out:
 854         if (rc)
 855                 ep->rep_connected = rc;
 856         return rc;
 857 }
 858
 859 /*
 860  * rpcrdma_ep_disconnect
 861  *
 862  * This is separate from destroy to facilitate the ability
 863  * to reconnect without recreating the endpoint.
 864  *
 865  * This call is not reentrant, and must not be made in parallel
 866  * on the same endpoint.
 867  */
 868 void
 869 rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 870 {
 871         int rc;
 872
 873         rpcrdma_flush_cqs(ep);
 874         rc = rdma_disconnect(ia->ri_id);
 875         if (!rc) {
 876                 /* returns without wait if not connected */
 877                 wait_event_interruptible(ep->rep_connect_wait,
 878                                                         ep->rep_connected != 1);
 879                 dprintk("RPC:       %s: after wait, %sconnected\n", __func__,
 880                         (ep->rep_connected == 1) ? "still " : "dis");
 881         } else {
 882                 dprintk("RPC:       %s: rdma_disconnect %i\n", __func__, rc);
 883                 ep->rep_connected = rc;
 884         }
 885 }
 886
 887 struct rpcrdma_req *
 888 rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
 889 {
 890         struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
 891         struct rpcrdma_req *req;
 892
 893         req = kzalloc(sizeof(*req), GFP_KERNEL);
 894         if (req == NULL)
 895                 return ERR_PTR(-ENOMEM);
 896
 897         INIT_LIST_HEAD(&req->rl_free);
 898         spin_lock(&buffer->rb_reqslock);
 899         list_add(&req->rl_all, &buffer->rb_allreqs);
 900         spin_unlock(&buffer->rb_reqslock);
 901         req->rl_buffer = &r_xprt->rx_buf;
 902         return req;
 903 }
 904
 905 struct rpcrdma_rep *
 906 rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
 907 {
 908         struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
 909         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 910         struct rpcrdma_rep *rep;
 911         int rc;
 912
 913         rc = -ENOMEM;
 914         rep = kzalloc(sizeof(*rep), GFP_KERNEL);
 915         if (rep == NULL)
 916                 goto out;
 917
 918         rep->rr_rdmabuf = rpcrdma_alloc_regbuf(ia, cdata->inline_rsize,
 919                                                GFP_KERNEL);
 920         if (IS_ERR(rep->rr_rdmabuf)) {
 921                 rc = PTR_ERR(rep->rr_rdmabuf);
 922                 goto out_free;
 923         }
 924
 925         rep->rr_device = ia->ri_device;
 926         rep->rr_rxprt = r_xprt;
 927         INIT_WORK(&rep->rr_work, rpcrdma_receive_worker);
 928         return rep;
 929
 930 out_free:
 931         kfree(rep);
 932 out:
 933         return ERR_PTR(rc);
 934 }
 935
 936 int
 937 rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 938 {
 939         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 940         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 941         int i, rc;
 942
 943         buf->rb_max_requests = r_xprt->rx_data.max_requests;
 944         buf->rb_bc_srv_max_requests = 0;
 945         spin_lock_init(&buf->rb_lock);
 946
 947         rc = ia->ri_ops->ro_init(r_xprt);
 948         if (rc)
 949                 goto out;
 950
 951         INIT_LIST_HEAD(&buf->rb_send_bufs);
 952         INIT_LIST_HEAD(&buf->rb_allreqs);
 953         spin_lock_init(&buf->rb_reqslock);
 954         for (i = 0; i < buf->rb_max_requests; i++) {
 955                 struct rpcrdma_req *req;
 956
 957                 req = rpcrdma_create_req(r_xprt);
 958                 if (IS_ERR(req)) {
 959                         dprintk("RPC:       %s: request buffer %d alloc"
 960                                 " failed\n", __func__, i);
 961                         rc = PTR_ERR(req);
 962                         goto out;
 963                 }
 964                 req->rl_backchannel = false;
 965                 list_add(&req->rl_free, &buf->rb_send_bufs);
 966         }
 967
 968         INIT_LIST_HEAD(&buf->rb_recv_bufs);
 969         for (i = 0; i < buf->rb_max_requests + 2; i++) {
 970                 struct rpcrdma_rep *rep;
 971
 972                 rep = rpcrdma_create_rep(r_xprt);
 973                 if (IS_ERR(rep)) {
 974                         dprintk("RPC:       %s: reply buffer %d alloc failed\n",
 975                                 __func__, i);
 976                         rc = PTR_ERR(rep);
 977                         goto out;
 978                 }
 979                 list_add(&rep->rr_list, &buf->rb_recv_bufs);
 980         }
 981
 982         return 0;
 983 out:
 984         rpcrdma_buffer_destroy(buf);
 985         return rc;
 986 }
 987
 988 static struct rpcrdma_req *
 989 rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
 990 {
 991         struct rpcrdma_req *req;
 992
 993         req = list_first_entry(&buf->rb_send_bufs,
 994                                struct rpcrdma_req, rl_free);
 995         list_del(&req->rl_free);
 996         return req;
 997 }
 998
 999 static struct rpcrdma_rep *
1000 rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
1001 {
1002         struct rpcrdma_rep *rep;
1003
1004         rep = list_first_entry(&buf->rb_recv_bufs,
1005                                struct rpcrdma_rep, rr_list);
1006         list_del(&rep->rr_list);
1007         return rep;
1008 }
1009
1010 static void
1011 rpcrdma_destroy_rep(struct rpcrdma_ia *ia, struct rpcrdma_rep *rep)
1012 {
1013         rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
1014         kfree(rep);
1015 }
1016
1017 void
1018 rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
1019 {
1020         rpcrdma_free_regbuf(ia, req->rl_sendbuf);
1021         rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
1022         kfree(req);
1023 }
1024
1025 void
1026 rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1027 {
1028         struct rpcrdma_ia *ia = rdmab_to_ia(buf);
1029
1030         while (!list_empty(&buf->rb_recv_bufs)) {
1031                 struct rpcrdma_rep *rep;
1032
1033                 rep = rpcrdma_buffer_get_rep_locked(buf);
1034                 rpcrdma_destroy_rep(ia, rep);
1035         }
1036
1037         spin_lock(&buf->rb_reqslock);
1038         while (!list_empty(&buf->rb_allreqs)) {
1039                 struct rpcrdma_req *req;
1040
1041                 req = list_first_entry(&buf->rb_allreqs,
1042                                        struct rpcrdma_req, rl_all);
1043                 list_del(&req->rl_all);
1044
1045                 spin_unlock(&buf->rb_reqslock);
1046                 rpcrdma_destroy_req(ia, req);
1047                 spin_lock(&buf->rb_reqslock);
1048         }
1049         spin_unlock(&buf->rb_reqslock);
1050
1051         ia->ri_ops->ro_destroy(buf);
1052 }
1053
1054 struct rpcrdma_mw *
1055 rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
1056 {
1057         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1058         struct rpcrdma_mw *mw = NULL;
1059
1060         spin_lock(&buf->rb_mwlock);
1061         if (!list_empty(&buf->rb_mws)) {
1062                 mw = list_first_entry(&buf->rb_mws,
1063                                       struct rpcrdma_mw, mw_list);
1064                 list_del_init(&mw->mw_list);
1065         }
1066         spin_unlock(&buf->rb_mwlock);
1067
1068         if (!mw)
1069                 pr_err("RPC:       %s: no MWs available\n", __func__);
1070         return mw;
1071 }
1072
1073 void
1074 rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
1075 {
1076         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1077
1078         spin_lock(&buf->rb_mwlock);
1079         list_add_tail(&mw->mw_list, &buf->rb_mws);
1080         spin_unlock(&buf->rb_mwlock);
1081 }
1082
1083 /*
1084  * Get a set of request/reply buffers.
1085  *
1086  * Reply buffer (if available) is attached to send buffer upon return.
1087  */
1088 struct rpcrdma_req *
1089 rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1090 {
1091         struct rpcrdma_req *req;
1092
1093         spin_lock(&buffers->rb_lock);
1094         if (list_empty(&buffers->rb_send_bufs))
1095                 goto out_reqbuf;
1096         req = rpcrdma_buffer_get_req_locked(buffers);
1097         if (list_empty(&buffers->rb_recv_bufs))
1098                 goto out_repbuf;
1099         req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
1100         spin_unlock(&buffers->rb_lock);
1101         return req;
1102
1103 out_reqbuf:
1104         spin_unlock(&buffers->rb_lock);
1105         pr_warn("RPC:       %s: out of request buffers\n", __func__);
1106         return NULL;
1107 out_repbuf:
1108         spin_unlock(&buffers->rb_lock);
1109         pr_warn("RPC:       %s: out of reply buffers\n", __func__);
1110         req->rl_reply = NULL;
1111         return req;
1112 }
1113
1114 /*
1115  * Put request/reply buffers back into pool.
1116  * Pre-decrement counter/array index.
1117  */
1118 void
1119 rpcrdma_buffer_put(struct rpcrdma_req *req)
1120 {
1121         struct rpcrdma_buffer *buffers = req->rl_buffer;
1122         struct rpcrdma_rep *rep = req->rl_reply;
1123
1124         req->rl_niovs = 0;
1125         req->rl_reply = NULL;
1126
1127         spin_lock(&buffers->rb_lock);
1128         list_add_tail(&req->rl_free, &buffers->rb_send_bufs);
1129         if (rep)
1130                 list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1131         spin_unlock(&buffers->rb_lock);
1132 }
1133
1134 /*
1135  * Recover reply buffers from pool.
1136  * This happens when recovering from disconnect.
1137  */
1138 void
1139 rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
1140 {
1141         struct rpcrdma_buffer *buffers = req->rl_buffer;
1142
1143         spin_lock(&buffers->rb_lock);
1144         if (!list_empty(&buffers->rb_recv_bufs))
1145                 req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
1146         spin_unlock(&buffers->rb_lock);
1147 }
1148
1149 /*
1150  * Put reply buffers back into pool when not attached to
1151  * request. This happens in error conditions.
1152  */
1153 void
1154 rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
1155 {
1156         struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1157
1158         spin_lock(&buffers->rb_lock);
1159         list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1160         spin_unlock(&buffers->rb_lock);
1161 }
1162
1163 /*
1164  * Wrappers for internal-use kmalloc memory registration, used by buffer code.
1165  */
1166
1167 void
1168 rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
1169 {
1170         dprintk("RPC:       map_one: offset %p iova %llx len %zu\n",
1171                 seg->mr_offset,
1172                 (unsigned long long)seg->mr_dma, seg->mr_dmalen);
1173 }
1174
1175 /**
1176  * rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers
1177  * @ia: controlling rpcrdma_ia
1178  * @size: size of buffer to be allocated, in bytes
1179  * @flags: GFP flags
1180  *
1181  * Returns pointer to private header of an area of internally
1182  * registered memory, or an ERR_PTR. The registered buffer follows
1183  * the end of the private header.
1184  *
1185  * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1186  * receiving the payload of RDMA RECV operations. regbufs are not
1187  * used for RDMA READ/WRITE operations, thus are registered only for
1188  * LOCAL access.
1189  */
1190 struct rpcrdma_regbuf *
1191 rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
1192 {
1193         struct rpcrdma_regbuf *rb;
1194         struct ib_sge *iov;
1195
1196         rb = kmalloc(sizeof(*rb) + size, flags);
1197         if (rb == NULL)
1198                 goto out;
1199
1200         iov = &rb->rg_iov;
1201         iov->addr = ib_dma_map_single(ia->ri_device,
1202                                       (void *)rb->rg_base, size,
1203                                       DMA_BIDIRECTIONAL);
1204         if (ib_dma_mapping_error(ia->ri_device, iov->addr))
1205                 goto out_free;
1206
1207         iov->length = size;
1208         iov->lkey = ia->ri_pd->local_dma_lkey;
1209         rb->rg_size = size;
1210         rb->rg_owner = NULL;
1211         return rb;
1212
1213 out_free:
1214         kfree(rb);
1215 out:
1216         return ERR_PTR(-ENOMEM);
1217 }
1218
1219 /**
1220  * rpcrdma_free_regbuf - deregister and free registered buffer
1221  * @ia: controlling rpcrdma_ia
1222  * @rb: regbuf to be deregistered and freed
1223  */
1224 void
1225 rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
1226 {
1227         struct ib_sge *iov;
1228
1229         if (!rb)
1230                 return;
1231
1232         iov = &rb->rg_iov;
1233         ib_dma_unmap_single(ia->ri_device,
1234                             iov->addr, iov->length, DMA_BIDIRECTIONAL);
1235         kfree(rb);
1236 }
1237
1238 /*
1239  * Prepost any receive buffer, then post send.
1240  *
1241  * Receive buffer is donated to hardware, reclaimed upon recv completion.
1242  */
1243 int
1244 rpcrdma_ep_post(struct rpcrdma_ia *ia,
1245                 struct rpcrdma_ep *ep,
1246                 struct rpcrdma_req *req)
1247 {
1248         struct ib_device *device = ia->ri_device;
1249         struct ib_send_wr send_wr, *send_wr_fail;
1250         struct rpcrdma_rep *rep = req->rl_reply;
1251         struct ib_sge *iov = req->rl_send_iov;
1252         int i, rc;
1253
1254         if (rep) {
1255                 rc = rpcrdma_ep_post_recv(ia, ep, rep);
1256                 if (rc)
1257                         goto out;
1258                 req->rl_reply = NULL;
1259         }
1260
1261         send_wr.next = NULL;
1262         send_wr.wr_id = RPCRDMA_IGNORE_COMPLETION;
1263         send_wr.sg_list = iov;
1264         send_wr.num_sge = req->rl_niovs;
1265         send_wr.opcode = IB_WR_SEND;
1266
1267         for (i = 0; i < send_wr.num_sge; i++)
1268                 ib_dma_sync_single_for_device(device, iov[i].addr,
1269                                               iov[i].length, DMA_TO_DEVICE);
1270         dprintk("RPC:       %s: posting %d s/g entries\n",
1271                 __func__, send_wr.num_sge);
1272
1273         if (DECR_CQCOUNT(ep) > 0)
1274                 send_wr.send_flags = 0;
1275         else { /* Provider must take a send completion every now and then */
1276                 INIT_CQCOUNT(ep);
1277                 send_wr.send_flags = IB_SEND_SIGNALED;
1278         }
1279
1280         rc = ib_post_send(ia->ri_id->qp, &send_wr, &send_wr_fail);
1281         if (rc)
1282                 dprintk("RPC:       %s: ib_post_send returned %i\n", __func__,
1283                         rc);
1284 out:
1285         return rc;
1286 }
1287
1288 /*
1289  * (Re)post a receive buffer.
1290  */
1291 int
1292 rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
1293                      struct rpcrdma_ep *ep,
1294                      struct rpcrdma_rep *rep)
1295 {
1296         struct ib_recv_wr recv_wr, *recv_wr_fail;
1297         int rc;
1298
1299         recv_wr.next = NULL;
1300         recv_wr.wr_id = (u64) (unsigned long) rep;
1301         recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
1302         recv_wr.num_sge = 1;
1303
1304         ib_dma_sync_single_for_cpu(ia->ri_device,
1305                                    rdmab_addr(rep->rr_rdmabuf),
1306                                    rdmab_length(rep->rr_rdmabuf),
1307                                    DMA_BIDIRECTIONAL);
1308
1309         rc = ib_post_recv(ia->ri_id->qp, &recv_wr, &recv_wr_fail);
1310
1311         if (rc)
1312                 dprintk("RPC:       %s: ib_post_recv returned %i\n", __func__,
1313                         rc);
1314         return rc;
1315 }
1316
1317 /**
1318  * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
1319  * @r_xprt: transport associated with these backchannel resources
1320  * @min_reqs: minimum number of incoming requests expected
1321  *
1322  * Returns zero if all requested buffers were posted, or a negative errno.
1323  */
1324 int
1325 rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
1326 {
1327         struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
1328         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
1329         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
1330         struct rpcrdma_rep *rep;
1331         int rc;
1332
1333         while (count--) {
1334                 spin_lock(&buffers->rb_lock);
1335                 if (list_empty(&buffers->rb_recv_bufs))
1336                         goto out_reqbuf;
1337                 rep = rpcrdma_buffer_get_rep_locked(buffers);
1338                 spin_unlock(&buffers->rb_lock);
1339
1340                 rc = rpcrdma_ep_post_recv(ia, ep, rep);
1341                 if (rc)
1342                         goto out_rc;
1343         }
1344
1345         return 0;
1346
1347 out_reqbuf:
1348         spin_unlock(&buffers->rb_lock);
1349         pr_warn("%s: no extra receive buffers\n", __func__);
1350         return -ENOMEM;
1351
1352 out_rc:
1353         rpcrdma_recv_buffer_put(rep);
1354         return rc;
1355 }
1356
1357 /* How many chunk list items fit within our inline buffers?
1358  */
1359 unsigned int
1360 rpcrdma_max_segments(struct rpcrdma_xprt *r_xprt)
1361 {
1362         struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
1363         int bytes, segments;
1364
1365         bytes = min_t(unsigned int, cdata->inline_wsize, cdata->inline_rsize);
1366         bytes -= RPCRDMA_HDRLEN_MIN;
1367         if (bytes < sizeof(struct rpcrdma_segment) * 2) {
1368                 pr_warn("RPC:       %s: inline threshold too small\n",
1369                         __func__);
1370                 return 0;
1371         }
1372
1373         segments = 1 << (fls(bytes / sizeof(struct rpcrdma_segment)) - 1);
1374         dprintk("RPC:       %s: max chunk list size = %d segments\n",
1375                 __func__, segments);
1376         return segments;
1377 }