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 <linux/sunrpc/svc_rdma.h>
  55 #include <asm/bitops.h>
  56
  57 #include <rdma/ib_cm.h>
  58
  59 #include "xprt_rdma.h"
  60
  61 /*
  62  * Globals/Macros
  63  */
  64
  65 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  66 # define RPCDBG_FACILITY        RPCDBG_TRANS
  67 #endif
  68
  69 /*
  70  * internal functions
  71  */
  72 static void rpcrdma_create_mrs(struct rpcrdma_xprt *r_xprt);
  73 static void rpcrdma_destroy_mrs(struct rpcrdma_buffer *buf);
  74 static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
  75
  76 static struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
  77
  78 int
  79 rpcrdma_alloc_wq(void)
  80 {
  81         struct workqueue_struct *recv_wq;
  82
  83         recv_wq = alloc_workqueue("xprtrdma_receive",
  84                                   WQ_MEM_RECLAIM | WQ_UNBOUND | WQ_HIGHPRI,
  85                                   0);
  86         if (!recv_wq)
  87                 return -ENOMEM;
  88
  89         rpcrdma_receive_wq = recv_wq;
  90         return 0;
  91 }
  92
  93 void
  94 rpcrdma_destroy_wq(void)
  95 {
  96         struct workqueue_struct *wq;
  97
  98         if (rpcrdma_receive_wq) {
  99                 wq = rpcrdma_receive_wq;
 100                 rpcrdma_receive_wq = NULL;
 101                 destroy_workqueue(wq);
 102         }
 103 }
 104
 105 static void
 106 rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
 107 {
 108         struct rpcrdma_ep *ep = context;
 109
 110         pr_err("rpcrdma: %s on device %s ep %p\n",
 111                ib_event_msg(event->event), event->device->name, context);
 112
 113         if (ep->rep_connected == 1) {
 114                 ep->rep_connected = -EIO;
 115                 rpcrdma_conn_func(ep);
 116                 wake_up_all(&ep->rep_connect_wait);
 117         }
 118 }
 119
 120 /**
 121  * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
 122  * @cq: completion queue (ignored)
 123  * @wc: completed WR
 124  *
 125  */
 126 static void
 127 rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
 128 {
 129         /* WARNING: Only wr_cqe and status are reliable at this point */
 130         if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
 131                 pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
 132                        ib_wc_status_msg(wc->status),
 133                        wc->status, wc->vendor_err);
 134 }
 135
 136 /* Perform basic sanity checking to avoid using garbage
 137  * to update the credit grant value.
 138  */
 139 static void
 140 rpcrdma_update_granted_credits(struct rpcrdma_rep *rep)
 141 {
 142         struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf);
 143         struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf;
 144         u32 credits;
 145
 146         if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
 147                 return;
 148
 149         credits = be32_to_cpu(rmsgp->rm_credit);
 150         if (credits == 0)
 151                 credits = 1;    /* don't deadlock */
 152         else if (credits > buffer->rb_max_requests)
 153                 credits = buffer->rb_max_requests;
 154
 155         atomic_set(&buffer->rb_credits, credits);
 156 }
 157
 158 /**
 159  * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
 160  * @cq: completion queue (ignored)
 161  * @wc: completed WR
 162  *
 163  */
 164 static void
 165 rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
 166 {
 167         struct ib_cqe *cqe = wc->wr_cqe;
 168         struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
 169                                                rr_cqe);
 170
 171         /* WARNING: Only wr_id and status are reliable at this point */
 172         if (wc->status != IB_WC_SUCCESS)
 173                 goto out_fail;
 174
 175         /* status == SUCCESS means all fields in wc are trustworthy */
 176         if (wc->opcode != IB_WC_RECV)
 177                 return;
 178
 179         dprintk("RPC:       %s: rep %p opcode 'recv', length %u: success\n",
 180                 __func__, rep, wc->byte_len);
 181
 182         rep->rr_len = wc->byte_len;
 183         rep->rr_wc_flags = wc->wc_flags;
 184         rep->rr_inv_rkey = wc->ex.invalidate_rkey;
 185
 186         ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
 187                                    rdmab_addr(rep->rr_rdmabuf),
 188                                    rep->rr_len, DMA_FROM_DEVICE);
 189
 190         rpcrdma_update_granted_credits(rep);
 191
 192 out_schedule:
 193         queue_work(rpcrdma_receive_wq, &rep->rr_work);
 194         return;
 195
 196 out_fail:
 197         if (wc->status != IB_WC_WR_FLUSH_ERR)
 198                 pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
 199                        ib_wc_status_msg(wc->status),
 200                        wc->status, wc->vendor_err);
 201         rep->rr_len = RPCRDMA_BAD_LEN;
 202         goto out_schedule;
 203 }
 204
 205 static void
 206 rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
 207                                struct rdma_conn_param *param)
 208 {
 209         struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
 210         const struct rpcrdma_connect_private *pmsg = param->private_data;
 211         unsigned int rsize, wsize;
 212
 213         /* Default settings for RPC-over-RDMA Version One */
 214         r_xprt->rx_ia.ri_reminv_expected = false;
 215         r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
 216         rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
 217         wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
 218
 219         if (pmsg &&
 220             pmsg->cp_magic == rpcrdma_cmp_magic &&
 221             pmsg->cp_version == RPCRDMA_CMP_VERSION) {
 222                 r_xprt->rx_ia.ri_reminv_expected = true;
 223                 r_xprt->rx_ia.ri_implicit_roundup = true;
 224                 rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
 225                 wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
 226         }
 227
 228         if (rsize < cdata->inline_rsize)
 229                 cdata->inline_rsize = rsize;
 230         if (wsize < cdata->inline_wsize)
 231                 cdata->inline_wsize = wsize;
 232         dprintk("RPC:       %s: max send %u, max recv %u\n",
 233                 __func__, cdata->inline_wsize, cdata->inline_rsize);
 234         rpcrdma_set_max_header_sizes(r_xprt);
 235 }
 236
 237 static int
 238 rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
 239 {
 240         struct rpcrdma_xprt *xprt = id->context;
 241         struct rpcrdma_ia *ia = &xprt->rx_ia;
 242         struct rpcrdma_ep *ep = &xprt->rx_ep;
 243 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 244         struct sockaddr *sap = (struct sockaddr *)&ep->rep_remote_addr;
 245 #endif
 246         int connstate = 0;
 247
 248         switch (event->event) {
 249         case RDMA_CM_EVENT_ADDR_RESOLVED:
 250         case RDMA_CM_EVENT_ROUTE_RESOLVED:
 251                 ia->ri_async_rc = 0;
 252                 complete(&ia->ri_done);
 253                 break;
 254         case RDMA_CM_EVENT_ADDR_ERROR:
 255                 ia->ri_async_rc = -EHOSTUNREACH;
 256                 dprintk("RPC:       %s: CM address resolution error, ep 0x%p\n",
 257                         __func__, ep);
 258                 complete(&ia->ri_done);
 259                 break;
 260         case RDMA_CM_EVENT_ROUTE_ERROR:
 261                 ia->ri_async_rc = -ENETUNREACH;
 262                 dprintk("RPC:       %s: CM route resolution error, ep 0x%p\n",
 263                         __func__, ep);
 264                 complete(&ia->ri_done);
 265                 break;
 266         case RDMA_CM_EVENT_DEVICE_REMOVAL:
 267 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 268                 pr_info("rpcrdma: removing device %s for %pIS:%u\n",
 269                         ia->ri_device->name,
 270                         sap, rpc_get_port(sap));
 271 #endif
 272                 set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
 273                 ep->rep_connected = -ENODEV;
 274                 xprt_force_disconnect(&xprt->rx_xprt);
 275                 wait_for_completion(&ia->ri_remove_done);
 276
 277                 ia->ri_id = NULL;
 278                 ia->ri_pd = NULL;
 279                 ia->ri_device = NULL;
 280                 /* Return 1 to ensure the core destroys the id. */
 281                 return 1;
 282         case RDMA_CM_EVENT_ESTABLISHED:
 283                 connstate = 1;
 284                 rpcrdma_update_connect_private(xprt, &event->param.conn);
 285                 goto connected;
 286         case RDMA_CM_EVENT_CONNECT_ERROR:
 287                 connstate = -ENOTCONN;
 288                 goto connected;
 289         case RDMA_CM_EVENT_UNREACHABLE:
 290                 connstate = -ENETDOWN;
 291                 goto connected;
 292         case RDMA_CM_EVENT_REJECTED:
 293                 dprintk("rpcrdma: connection to %pIS:%u rejected: %s\n",
 294                         sap, rpc_get_port(sap),
 295                         rdma_reject_msg(id, event->status));
 296                 connstate = -ECONNREFUSED;
 297                 if (event->status == IB_CM_REJ_STALE_CONN)
 298                         connstate = -EAGAIN;
 299                 goto connected;
 300         case RDMA_CM_EVENT_DISCONNECTED:
 301                 connstate = -ECONNABORTED;
 302 connected:
 303                 atomic_set(&xprt->rx_buf.rb_credits, 1);
 304                 ep->rep_connected = connstate;
 305                 rpcrdma_conn_func(ep);
 306                 wake_up_all(&ep->rep_connect_wait);
 307                 /*FALLTHROUGH*/
 308         default:
 309                 dprintk("RPC:       %s: %pIS:%u on %s/%s (ep 0x%p): %s\n",
 310                         __func__, sap, rpc_get_port(sap),
 311                         ia->ri_device->name, ia->ri_ops->ro_displayname,
 312                         ep, rdma_event_msg(event->event));
 313                 break;
 314         }
 315
 316         return 0;
 317 }
 318
 319 static struct rdma_cm_id *
 320 rpcrdma_create_id(struct rpcrdma_xprt *xprt,
 321                         struct rpcrdma_ia *ia, struct sockaddr *addr)
 322 {
 323         unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
 324         struct rdma_cm_id *id;
 325         int rc;
 326
 327         init_completion(&ia->ri_done);
 328         init_completion(&ia->ri_remove_done);
 329
 330         id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
 331                             IB_QPT_RC);
 332         if (IS_ERR(id)) {
 333                 rc = PTR_ERR(id);
 334                 dprintk("RPC:       %s: rdma_create_id() failed %i\n",
 335                         __func__, rc);
 336                 return id;
 337         }
 338
 339         ia->ri_async_rc = -ETIMEDOUT;
 340         rc = rdma_resolve_addr(id, NULL, addr, RDMA_RESOLVE_TIMEOUT);
 341         if (rc) {
 342                 dprintk("RPC:       %s: rdma_resolve_addr() failed %i\n",
 343                         __func__, rc);
 344                 goto out;
 345         }
 346         rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
 347         if (rc < 0) {
 348                 dprintk("RPC:       %s: wait() exited: %i\n",
 349                         __func__, rc);
 350                 goto out;
 351         }
 352
 353         rc = ia->ri_async_rc;
 354         if (rc)
 355                 goto out;
 356
 357         ia->ri_async_rc = -ETIMEDOUT;
 358         rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
 359         if (rc) {
 360                 dprintk("RPC:       %s: rdma_resolve_route() failed %i\n",
 361                         __func__, rc);
 362                 goto out;
 363         }
 364         rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
 365         if (rc < 0) {
 366                 dprintk("RPC:       %s: wait() exited: %i\n",
 367                         __func__, rc);
 368                 goto out;
 369         }
 370         rc = ia->ri_async_rc;
 371         if (rc)
 372                 goto out;
 373
 374         return id;
 375
 376 out:
 377         rdma_destroy_id(id);
 378         return ERR_PTR(rc);
 379 }
 380
 381 /*
 382  * Exported functions.
 383  */
 384
 385 /**
 386  * rpcrdma_ia_open - Open and initialize an Interface Adapter.
 387  * @xprt: controlling transport
 388  * @addr: IP address of remote peer
 389  *
 390  * Returns 0 on success, negative errno if an appropriate
 391  * Interface Adapter could not be found and opened.
 392  */
 393 int
 394 rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr)
 395 {
 396         struct rpcrdma_ia *ia = &xprt->rx_ia;
 397         int rc;
 398
 399         ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
 400         if (IS_ERR(ia->ri_id)) {
 401                 rc = PTR_ERR(ia->ri_id);
 402                 goto out_err;
 403         }
 404         ia->ri_device = ia->ri_id->device;
 405
 406         ia->ri_pd = ib_alloc_pd(ia->ri_device, 0);
 407         if (IS_ERR(ia->ri_pd)) {
 408                 rc = PTR_ERR(ia->ri_pd);
 409                 pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
 410                 goto out_err;
 411         }
 412
 413         switch (xprt_rdma_memreg_strategy) {
 414         case RPCRDMA_FRMR:
 415                 if (frwr_is_supported(ia)) {
 416                         ia->ri_ops = &rpcrdma_frwr_memreg_ops;
 417                         break;
 418                 }
 419                 /*FALLTHROUGH*/
 420         case RPCRDMA_MTHCAFMR:
 421                 if (fmr_is_supported(ia)) {
 422                         ia->ri_ops = &rpcrdma_fmr_memreg_ops;
 423                         break;
 424                 }
 425                 /*FALLTHROUGH*/
 426         default:
 427                 pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
 428                        ia->ri_device->name, xprt_rdma_memreg_strategy);
 429                 rc = -EINVAL;
 430                 goto out_err;
 431         }
 432
 433         return 0;
 434
 435 out_err:
 436         rpcrdma_ia_close(ia);
 437         return rc;
 438 }
 439
 440 /**
 441  * rpcrdma_ia_remove - Handle device driver unload
 442  * @ia: interface adapter being removed
 443  *
 444  * Divest transport H/W resources associated with this adapter,
 445  * but allow it to be restored later.
 446  */
 447 void
 448 rpcrdma_ia_remove(struct rpcrdma_ia *ia)
 449 {
 450         struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
 451                                                    rx_ia);
 452         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 453         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 454         struct rpcrdma_req *req;
 455         struct rpcrdma_rep *rep;
 456
 457         cancel_delayed_work_sync(&buf->rb_refresh_worker);
 458
 459         /* This is similar to rpcrdma_ep_destroy, but:
 460          * - Don't cancel the connect worker.
 461          * - Don't call rpcrdma_ep_disconnect, which waits
 462          *   for another conn upcall, which will deadlock.
 463          * - rdma_disconnect is unneeded, the underlying
 464          *   connection is already gone.
 465          */
 466         if (ia->ri_id->qp) {
 467                 ib_drain_qp(ia->ri_id->qp);
 468                 rdma_destroy_qp(ia->ri_id);
 469                 ia->ri_id->qp = NULL;
 470         }
 471         ib_free_cq(ep->rep_attr.recv_cq);
 472         ib_free_cq(ep->rep_attr.send_cq);
 473
 474         /* The ULP is responsible for ensuring all DMA
 475          * mappings and MRs are gone.
 476          */
 477         list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
 478                 rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
 479         list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
 480                 rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
 481                 rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
 482                 rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
 483         }
 484         rpcrdma_destroy_mrs(buf);
 485
 486         /* Allow waiters to continue */
 487         complete(&ia->ri_remove_done);
 488 }
 489
 490 /**
 491  * rpcrdma_ia_close - Clean up/close an IA.
 492  * @ia: interface adapter to close
 493  *
 494  */
 495 void
 496 rpcrdma_ia_close(struct rpcrdma_ia *ia)
 497 {
 498         dprintk("RPC:       %s: entering\n", __func__);
 499         if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
 500                 if (ia->ri_id->qp)
 501                         rdma_destroy_qp(ia->ri_id);
 502                 rdma_destroy_id(ia->ri_id);
 503         }
 504         ia->ri_id = NULL;
 505         ia->ri_device = NULL;
 506
 507         /* If the pd is still busy, xprtrdma missed freeing a resource */
 508         if (ia->ri_pd && !IS_ERR(ia->ri_pd))
 509                 ib_dealloc_pd(ia->ri_pd);
 510         ia->ri_pd = NULL;
 511 }
 512
 513 /*
 514  * Create unconnected endpoint.
 515  */
 516 int
 517 rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
 518                   struct rpcrdma_create_data_internal *cdata)
 519 {
 520         struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
 521         unsigned int max_qp_wr, max_sge;
 522         struct ib_cq *sendcq, *recvcq;
 523         int rc;
 524
 525         max_sge = min_t(unsigned int, ia->ri_device->attrs.max_sge,
 526                         RPCRDMA_MAX_SEND_SGES);
 527         if (max_sge < RPCRDMA_MIN_SEND_SGES) {
 528                 pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
 529                 return -ENOMEM;
 530         }
 531         ia->ri_max_send_sges = max_sge - RPCRDMA_MIN_SEND_SGES;
 532
 533         if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
 534                 dprintk("RPC:       %s: insufficient wqe's available\n",
 535                         __func__);
 536                 return -ENOMEM;
 537         }
 538         max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS - 1;
 539
 540         /* check provider's send/recv wr limits */
 541         if (cdata->max_requests > max_qp_wr)
 542                 cdata->max_requests = max_qp_wr;
 543
 544         ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
 545         ep->rep_attr.qp_context = ep;
 546         ep->rep_attr.srq = NULL;
 547         ep->rep_attr.cap.max_send_wr = cdata->max_requests;
 548         ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
 549         ep->rep_attr.cap.max_send_wr += 1;      /* drain cqe */
 550         rc = ia->ri_ops->ro_open(ia, ep, cdata);
 551         if (rc)
 552                 return rc;
 553         ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
 554         ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
 555         ep->rep_attr.cap.max_recv_wr += 1;      /* drain cqe */
 556         ep->rep_attr.cap.max_send_sge = max_sge;
 557         ep->rep_attr.cap.max_recv_sge = 1;
 558         ep->rep_attr.cap.max_inline_data = 0;
 559         ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 560         ep->rep_attr.qp_type = IB_QPT_RC;
 561         ep->rep_attr.port_num = ~0;
 562
 563         dprintk("RPC:       %s: requested max: dtos: send %d recv %d; "
 564                 "iovs: send %d recv %d\n",
 565                 __func__,
 566                 ep->rep_attr.cap.max_send_wr,
 567                 ep->rep_attr.cap.max_recv_wr,
 568                 ep->rep_attr.cap.max_send_sge,
 569                 ep->rep_attr.cap.max_recv_sge);
 570
 571         /* set trigger for requesting send completion */
 572         ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
 573         if (ep->rep_cqinit <= 2)
 574                 ep->rep_cqinit = 0;     /* always signal? */
 575         rpcrdma_init_cqcount(ep, 0);
 576         init_waitqueue_head(&ep->rep_connect_wait);
 577         INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
 578
 579         sendcq = ib_alloc_cq(ia->ri_device, NULL,
 580                              ep->rep_attr.cap.max_send_wr + 1,
 581                              0, IB_POLL_SOFTIRQ);
 582         if (IS_ERR(sendcq)) {
 583                 rc = PTR_ERR(sendcq);
 584                 dprintk("RPC:       %s: failed to create send CQ: %i\n",
 585                         __func__, rc);
 586                 goto out1;
 587         }
 588
 589         recvcq = ib_alloc_cq(ia->ri_device, NULL,
 590                              ep->rep_attr.cap.max_recv_wr + 1,
 591                              0, IB_POLL_SOFTIRQ);
 592         if (IS_ERR(recvcq)) {
 593                 rc = PTR_ERR(recvcq);
 594                 dprintk("RPC:       %s: failed to create recv CQ: %i\n",
 595                         __func__, rc);
 596                 goto out2;
 597         }
 598
 599         ep->rep_attr.send_cq = sendcq;
 600         ep->rep_attr.recv_cq = recvcq;
 601
 602         /* Initialize cma parameters */
 603         memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
 604
 605         /* Prepare RDMA-CM private message */
 606         pmsg->cp_magic = rpcrdma_cmp_magic;
 607         pmsg->cp_version = RPCRDMA_CMP_VERSION;
 608         pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
 609         pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);
 610         pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);
 611         ep->rep_remote_cma.private_data = pmsg;
 612         ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
 613
 614         /* Client offers RDMA Read but does not initiate */
 615         ep->rep_remote_cma.initiator_depth = 0;
 616         if (ia->ri_device->attrs.max_qp_rd_atom > 32)   /* arbitrary but <= 255 */
 617                 ep->rep_remote_cma.responder_resources = 32;
 618         else
 619                 ep->rep_remote_cma.responder_resources =
 620                                                 ia->ri_device->attrs.max_qp_rd_atom;
 621
 622         /* Limit transport retries so client can detect server
 623          * GID changes quickly. RPC layer handles re-establishing
 624          * transport connection and retransmission.
 625          */
 626         ep->rep_remote_cma.retry_count = 6;
 627
 628         /* RPC-over-RDMA handles its own flow control. In addition,
 629          * make all RNR NAKs visible so we know that RPC-over-RDMA
 630          * flow control is working correctly (no NAKs should be seen).
 631          */
 632         ep->rep_remote_cma.flow_control = 0;
 633         ep->rep_remote_cma.rnr_retry_count = 0;
 634
 635         return 0;
 636
 637 out2:
 638         ib_free_cq(sendcq);
 639 out1:
 640         return rc;
 641 }
 642
 643 /*
 644  * rpcrdma_ep_destroy
 645  *
 646  * Disconnect and destroy endpoint. After this, the only
 647  * valid operations on the ep are to free it (if dynamically
 648  * allocated) or re-create it.
 649  */
 650 void
 651 rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 652 {
 653         dprintk("RPC:       %s: entering, connected is %d\n",
 654                 __func__, ep->rep_connected);
 655
 656         cancel_delayed_work_sync(&ep->rep_connect_worker);
 657
 658         if (ia->ri_id->qp) {
 659                 rpcrdma_ep_disconnect(ep, ia);
 660                 rdma_destroy_qp(ia->ri_id);
 661                 ia->ri_id->qp = NULL;
 662         }
 663
 664         ib_free_cq(ep->rep_attr.recv_cq);
 665         ib_free_cq(ep->rep_attr.send_cq);
 666 }
 667
 668 /* Re-establish a connection after a device removal event.
 669  * Unlike a normal reconnection, a fresh PD and a new set
 670  * of MRs and buffers is needed.
 671  */
 672 static int
 673 rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
 674                          struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 675 {
 676         struct sockaddr *sap = (struct sockaddr *)&r_xprt->rx_data.addr;
 677         int rc, err;
 678
 679         pr_info("%s: r_xprt = %p\n", __func__, r_xprt);
 680
 681         rc = -EHOSTUNREACH;
 682         if (rpcrdma_ia_open(r_xprt, sap))
 683                 goto out1;
 684
 685         rc = -ENOMEM;
 686         err = rpcrdma_ep_create(ep, ia, &r_xprt->rx_data);
 687         if (err) {
 688                 pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
 689                 goto out2;
 690         }
 691
 692         rc = -ENETUNREACH;
 693         err = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
 694         if (err) {
 695                 pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
 696                 goto out3;
 697         }
 698
 699         rpcrdma_create_mrs(r_xprt);
 700         return 0;
 701
 702 out3:
 703         rpcrdma_ep_destroy(ep, ia);
 704 out2:
 705         rpcrdma_ia_close(ia);
 706 out1:
 707         return rc;
 708 }
 709
 710 static int
 711 rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
 712                      struct rpcrdma_ia *ia)
 713 {
 714         struct sockaddr *sap = (struct sockaddr *)&r_xprt->rx_data.addr;
 715         struct rdma_cm_id *id, *old;
 716         int err, rc;
 717
 718         dprintk("RPC:       %s: reconnecting...\n", __func__);
 719
 720         rpcrdma_ep_disconnect(ep, ia);
 721
 722         rc = -EHOSTUNREACH;
 723         id = rpcrdma_create_id(r_xprt, ia, sap);
 724         if (IS_ERR(id))
 725                 goto out;
 726
 727         /* As long as the new ID points to the same device as the
 728          * old ID, we can reuse the transport's existing PD and all
 729          * previously allocated MRs. Also, the same device means
 730          * the transport's previous DMA mappings are still valid.
 731          *
 732          * This is a sanity check only. There should be no way these
 733          * point to two different devices here.
 734          */
 735         old = id;
 736         rc = -ENETUNREACH;
 737         if (ia->ri_device != id->device) {
 738                 pr_err("rpcrdma: can't reconnect on different device!\n");
 739                 goto out_destroy;
 740         }
 741
 742         err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
 743         if (err) {
 744                 dprintk("RPC:       %s: rdma_create_qp returned %d\n",
 745                         __func__, err);
 746                 goto out_destroy;
 747         }
 748
 749         /* Atomically replace the transport's ID and QP. */
 750         rc = 0;
 751         old = ia->ri_id;
 752         ia->ri_id = id;
 753         rdma_destroy_qp(old);
 754
 755 out_destroy:
 756         rdma_destroy_id(old);
 757 out:
 758         return rc;
 759 }
 760
 761 /*
 762  * Connect unconnected endpoint.
 763  */
 764 int
 765 rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 766 {
 767         struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
 768                                                    rx_ia);
 769         unsigned int extras;
 770         int rc;
 771
 772 retry:
 773         switch (ep->rep_connected) {
 774         case 0:
 775                 dprintk("RPC:       %s: connecting...\n", __func__);
 776                 rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
 777                 if (rc) {
 778                         dprintk("RPC:       %s: rdma_create_qp failed %i\n",
 779                                 __func__, rc);
 780                         rc = -ENETUNREACH;
 781                         goto out_noupdate;
 782                 }
 783                 break;
 784         case -ENODEV:
 785                 rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
 786                 if (rc)
 787                         goto out_noupdate;
 788                 break;
 789         default:
 790                 rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
 791                 if (rc)
 792                         goto out;
 793         }
 794
 795         ep->rep_connected = 0;
 796
 797         rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
 798         if (rc) {
 799                 dprintk("RPC:       %s: rdma_connect() failed with %i\n",
 800                                 __func__, rc);
 801                 goto out;
 802         }
 803
 804         wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
 805         if (ep->rep_connected <= 0) {
 806                 if (ep->rep_connected == -EAGAIN)
 807                         goto retry;
 808                 rc = ep->rep_connected;
 809                 goto out;
 810         }
 811
 812         dprintk("RPC:       %s: connected\n", __func__);
 813         extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
 814         if (extras)
 815                 rpcrdma_ep_post_extra_recv(r_xprt, extras);
 816
 817 out:
 818         if (rc)
 819                 ep->rep_connected = rc;
 820
 821 out_noupdate:
 822         return rc;
 823 }
 824
 825 /*
 826  * rpcrdma_ep_disconnect
 827  *
 828  * This is separate from destroy to facilitate the ability
 829  * to reconnect without recreating the endpoint.
 830  *
 831  * This call is not reentrant, and must not be made in parallel
 832  * on the same endpoint.
 833  */
 834 void
 835 rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
 836 {
 837         int rc;
 838
 839         rc = rdma_disconnect(ia->ri_id);
 840         if (!rc) {
 841                 /* returns without wait if not connected */
 842                 wait_event_interruptible(ep->rep_connect_wait,
 843                                                         ep->rep_connected != 1);
 844                 dprintk("RPC:       %s: after wait, %sconnected\n", __func__,
 845                         (ep->rep_connected == 1) ? "still " : "dis");
 846         } else {
 847                 dprintk("RPC:       %s: rdma_disconnect %i\n", __func__, rc);
 848                 ep->rep_connected = rc;
 849         }
 850
 851         ib_drain_qp(ia->ri_id->qp);
 852 }
 853
 854 static void
 855 rpcrdma_mr_recovery_worker(struct work_struct *work)
 856 {
 857         struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
 858                                                   rb_recovery_worker.work);
 859         struct rpcrdma_mw *mw;
 860
 861         spin_lock(&buf->rb_recovery_lock);
 862         while (!list_empty(&buf->rb_stale_mrs)) {
 863                 mw = rpcrdma_pop_mw(&buf->rb_stale_mrs);
 864                 spin_unlock(&buf->rb_recovery_lock);
 865
 866                 dprintk("RPC:       %s: recovering MR %p\n", __func__, mw);
 867                 mw->mw_xprt->rx_ia.ri_ops->ro_recover_mr(mw);
 868
 869                 spin_lock(&buf->rb_recovery_lock);
 870         }
 871         spin_unlock(&buf->rb_recovery_lock);
 872 }
 873
 874 void
 875 rpcrdma_defer_mr_recovery(struct rpcrdma_mw *mw)
 876 {
 877         struct rpcrdma_xprt *r_xprt = mw->mw_xprt;
 878         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 879
 880         spin_lock(&buf->rb_recovery_lock);
 881         rpcrdma_push_mw(mw, &buf->rb_stale_mrs);
 882         spin_unlock(&buf->rb_recovery_lock);
 883
 884         schedule_delayed_work(&buf->rb_recovery_worker, 0);
 885 }
 886
 887 static void
 888 rpcrdma_create_mrs(struct rpcrdma_xprt *r_xprt)
 889 {
 890         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 891         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 892         unsigned int count;
 893         LIST_HEAD(free);
 894         LIST_HEAD(all);
 895
 896         for (count = 0; count < 32; count++) {
 897                 struct rpcrdma_mw *mw;
 898                 int rc;
 899
 900                 mw = kzalloc(sizeof(*mw), GFP_KERNEL);
 901                 if (!mw)
 902                         break;
 903
 904                 rc = ia->ri_ops->ro_init_mr(ia, mw);
 905                 if (rc) {
 906                         kfree(mw);
 907                         break;
 908                 }
 909
 910                 mw->mw_xprt = r_xprt;
 911
 912                 list_add(&mw->mw_list, &free);
 913                 list_add(&mw->mw_all, &all);
 914         }
 915
 916         spin_lock(&buf->rb_mwlock);
 917         list_splice(&free, &buf->rb_mws);
 918         list_splice(&all, &buf->rb_all);
 919         r_xprt->rx_stats.mrs_allocated += count;
 920         spin_unlock(&buf->rb_mwlock);
 921
 922         dprintk("RPC:       %s: created %u MRs\n", __func__, count);
 923 }
 924
 925 static void
 926 rpcrdma_mr_refresh_worker(struct work_struct *work)
 927 {
 928         struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
 929                                                   rb_refresh_worker.work);
 930         struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
 931                                                    rx_buf);
 932
 933         rpcrdma_create_mrs(r_xprt);
 934 }
 935
 936 struct rpcrdma_req *
 937 rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
 938 {
 939         struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
 940         struct rpcrdma_req *req;
 941
 942         req = kzalloc(sizeof(*req), GFP_KERNEL);
 943         if (req == NULL)
 944                 return ERR_PTR(-ENOMEM);
 945
 946         spin_lock(&buffer->rb_reqslock);
 947         list_add(&req->rl_all, &buffer->rb_allreqs);
 948         spin_unlock(&buffer->rb_reqslock);
 949         req->rl_cqe.done = rpcrdma_wc_send;
 950         req->rl_buffer = &r_xprt->rx_buf;
 951         INIT_LIST_HEAD(&req->rl_registered);
 952         req->rl_send_wr.next = NULL;
 953         req->rl_send_wr.wr_cqe = &req->rl_cqe;
 954         req->rl_send_wr.sg_list = req->rl_send_sge;
 955         req->rl_send_wr.opcode = IB_WR_SEND;
 956         return req;
 957 }
 958
 959 struct rpcrdma_rep *
 960 rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
 961 {
 962         struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
 963         struct rpcrdma_rep *rep;
 964         int rc;
 965
 966         rc = -ENOMEM;
 967         rep = kzalloc(sizeof(*rep), GFP_KERNEL);
 968         if (rep == NULL)
 969                 goto out;
 970
 971         rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
 972                                                DMA_FROM_DEVICE, GFP_KERNEL);
 973         if (IS_ERR(rep->rr_rdmabuf)) {
 974                 rc = PTR_ERR(rep->rr_rdmabuf);
 975                 goto out_free;
 976         }
 977
 978         rep->rr_cqe.done = rpcrdma_wc_receive;
 979         rep->rr_rxprt = r_xprt;
 980         INIT_WORK(&rep->rr_work, rpcrdma_reply_handler);
 981         rep->rr_recv_wr.next = NULL;
 982         rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
 983         rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
 984         rep->rr_recv_wr.num_sge = 1;
 985         return rep;
 986
 987 out_free:
 988         kfree(rep);
 989 out:
 990         return ERR_PTR(rc);
 991 }
 992
 993 int
 994 rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
 995 {
 996         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
 997         int i, rc;
 998
 999         buf->rb_max_requests = r_xprt->rx_data.max_requests;
1000         buf->rb_bc_srv_max_requests = 0;
1001         atomic_set(&buf->rb_credits, 1);
1002         spin_lock_init(&buf->rb_mwlock);
1003         spin_lock_init(&buf->rb_lock);
1004         spin_lock_init(&buf->rb_recovery_lock);
1005         INIT_LIST_HEAD(&buf->rb_mws);
1006         INIT_LIST_HEAD(&buf->rb_all);
1007         INIT_LIST_HEAD(&buf->rb_pending);
1008         INIT_LIST_HEAD(&buf->rb_stale_mrs);
1009         INIT_DELAYED_WORK(&buf->rb_refresh_worker,
1010                           rpcrdma_mr_refresh_worker);
1011         INIT_DELAYED_WORK(&buf->rb_recovery_worker,
1012                           rpcrdma_mr_recovery_worker);
1013
1014         rpcrdma_create_mrs(r_xprt);
1015
1016         INIT_LIST_HEAD(&buf->rb_send_bufs);
1017         INIT_LIST_HEAD(&buf->rb_allreqs);
1018         spin_lock_init(&buf->rb_reqslock);
1019         for (i = 0; i < buf->rb_max_requests; i++) {
1020                 struct rpcrdma_req *req;
1021
1022                 req = rpcrdma_create_req(r_xprt);
1023                 if (IS_ERR(req)) {
1024                         dprintk("RPC:       %s: request buffer %d alloc"
1025                                 " failed\n", __func__, i);
1026                         rc = PTR_ERR(req);
1027                         goto out;
1028                 }
1029                 req->rl_backchannel = false;
1030                 list_add(&req->rl_list, &buf->rb_send_bufs);
1031         }
1032
1033         INIT_LIST_HEAD(&buf->rb_recv_bufs);
1034         for (i = 0; i < buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS; i++) {
1035                 struct rpcrdma_rep *rep;
1036
1037                 rep = rpcrdma_create_rep(r_xprt);
1038                 if (IS_ERR(rep)) {
1039                         dprintk("RPC:       %s: reply buffer %d alloc failed\n",
1040                                 __func__, i);
1041                         rc = PTR_ERR(rep);
1042                         goto out;
1043                 }
1044                 list_add(&rep->rr_list, &buf->rb_recv_bufs);
1045         }
1046
1047         return 0;
1048 out:
1049         rpcrdma_buffer_destroy(buf);
1050         return rc;
1051 }
1052
1053 static struct rpcrdma_req *
1054 rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
1055 {
1056         struct rpcrdma_req *req;
1057
1058         req = list_first_entry(&buf->rb_send_bufs,
1059                                struct rpcrdma_req, rl_list);
1060         list_del_init(&req->rl_list);
1061         return req;
1062 }
1063
1064 static struct rpcrdma_rep *
1065 rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
1066 {
1067         struct rpcrdma_rep *rep;
1068
1069         rep = list_first_entry(&buf->rb_recv_bufs,
1070                                struct rpcrdma_rep, rr_list);
1071         list_del(&rep->rr_list);
1072         return rep;
1073 }
1074
1075 static void
1076 rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
1077 {
1078         rpcrdma_free_regbuf(rep->rr_rdmabuf);
1079         kfree(rep);
1080 }
1081
1082 void
1083 rpcrdma_destroy_req(struct rpcrdma_req *req)
1084 {
1085         rpcrdma_free_regbuf(req->rl_recvbuf);
1086         rpcrdma_free_regbuf(req->rl_sendbuf);
1087         rpcrdma_free_regbuf(req->rl_rdmabuf);
1088         kfree(req);
1089 }
1090
1091 static void
1092 rpcrdma_destroy_mrs(struct rpcrdma_buffer *buf)
1093 {
1094         struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
1095                                                    rx_buf);
1096         struct rpcrdma_ia *ia = rdmab_to_ia(buf);
1097         struct rpcrdma_mw *mw;
1098         unsigned int count;
1099
1100         count = 0;
1101         spin_lock(&buf->rb_mwlock);
1102         while (!list_empty(&buf->rb_all)) {
1103                 mw = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all);
1104                 list_del(&mw->mw_all);
1105
1106                 spin_unlock(&buf->rb_mwlock);
1107                 ia->ri_ops->ro_release_mr(mw);
1108                 count++;
1109                 spin_lock(&buf->rb_mwlock);
1110         }
1111         spin_unlock(&buf->rb_mwlock);
1112         r_xprt->rx_stats.mrs_allocated = 0;
1113
1114         dprintk("RPC:       %s: released %u MRs\n", __func__, count);
1115 }
1116
1117 void
1118 rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1119 {
1120         cancel_delayed_work_sync(&buf->rb_recovery_worker);
1121         cancel_delayed_work_sync(&buf->rb_refresh_worker);
1122
1123         while (!list_empty(&buf->rb_recv_bufs)) {
1124                 struct rpcrdma_rep *rep;
1125
1126                 rep = rpcrdma_buffer_get_rep_locked(buf);
1127                 rpcrdma_destroy_rep(rep);
1128         }
1129         buf->rb_send_count = 0;
1130
1131         spin_lock(&buf->rb_reqslock);
1132         while (!list_empty(&buf->rb_allreqs)) {
1133                 struct rpcrdma_req *req;
1134
1135                 req = list_first_entry(&buf->rb_allreqs,
1136                                        struct rpcrdma_req, rl_all);
1137                 list_del(&req->rl_all);
1138
1139                 spin_unlock(&buf->rb_reqslock);
1140                 rpcrdma_destroy_req(req);
1141                 spin_lock(&buf->rb_reqslock);
1142         }
1143         spin_unlock(&buf->rb_reqslock);
1144         buf->rb_recv_count = 0;
1145
1146         rpcrdma_destroy_mrs(buf);
1147 }
1148
1149 struct rpcrdma_mw *
1150 rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
1151 {
1152         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1153         struct rpcrdma_mw *mw = NULL;
1154
1155         spin_lock(&buf->rb_mwlock);
1156         if (!list_empty(&buf->rb_mws))
1157                 mw = rpcrdma_pop_mw(&buf->rb_mws);
1158         spin_unlock(&buf->rb_mwlock);
1159
1160         if (!mw)
1161                 goto out_nomws;
1162         mw->mw_flags = 0;
1163         return mw;
1164
1165 out_nomws:
1166         dprintk("RPC:       %s: no MWs available\n", __func__);
1167         if (r_xprt->rx_ep.rep_connected != -ENODEV)
1168                 schedule_delayed_work(&buf->rb_refresh_worker, 0);
1169
1170         /* Allow the reply handler and refresh worker to run */
1171         cond_resched();
1172
1173         return NULL;
1174 }
1175
1176 void
1177 rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
1178 {
1179         struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1180
1181         spin_lock(&buf->rb_mwlock);
1182         rpcrdma_push_mw(mw, &buf->rb_mws);
1183         spin_unlock(&buf->rb_mwlock);
1184 }
1185
1186 static struct rpcrdma_rep *
1187 rpcrdma_buffer_get_rep(struct rpcrdma_buffer *buffers)
1188 {
1189         /* If an RPC previously completed without a reply (say, a
1190          * credential problem or a soft timeout occurs) then hold off
1191          * on supplying more Receive buffers until the number of new
1192          * pending RPCs catches up to the number of posted Receives.
1193          */
1194         if (unlikely(buffers->rb_send_count < buffers->rb_recv_count))
1195                 return NULL;
1196
1197         if (unlikely(list_empty(&buffers->rb_recv_bufs)))
1198                 return NULL;
1199         buffers->rb_recv_count++;
1200         return rpcrdma_buffer_get_rep_locked(buffers);
1201 }
1202
1203 /*
1204  * Get a set of request/reply buffers.
1205  *
1206  * Reply buffer (if available) is attached to send buffer upon return.
1207  */
1208 struct rpcrdma_req *
1209 rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1210 {
1211         struct rpcrdma_req *req;
1212
1213         spin_lock(&buffers->rb_lock);
1214         if (list_empty(&buffers->rb_send_bufs))
1215                 goto out_reqbuf;
1216         buffers->rb_send_count++;
1217         req = rpcrdma_buffer_get_req_locked(buffers);
1218         req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1219         spin_unlock(&buffers->rb_lock);
1220         return req;
1221
1222 out_reqbuf:
1223         spin_unlock(&buffers->rb_lock);
1224         pr_warn("RPC:       %s: out of request buffers\n", __func__);
1225         return NULL;
1226 }
1227
1228 /*
1229  * Put request/reply buffers back into pool.
1230  * Pre-decrement counter/array index.
1231  */
1232 void
1233 rpcrdma_buffer_put(struct rpcrdma_req *req)
1234 {
1235         struct rpcrdma_buffer *buffers = req->rl_buffer;
1236         struct rpcrdma_rep *rep = req->rl_reply;
1237
1238         req->rl_send_wr.num_sge = 0;
1239         req->rl_reply = NULL;
1240
1241         spin_lock(&buffers->rb_lock);
1242         buffers->rb_send_count--;
1243         list_add_tail(&req->rl_list, &buffers->rb_send_bufs);
1244         if (rep) {
1245                 buffers->rb_recv_count--;
1246                 list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1247         }
1248         spin_unlock(&buffers->rb_lock);
1249 }
1250
1251 /*
1252  * Recover reply buffers from pool.
1253  * This happens when recovering from disconnect.
1254  */
1255 void
1256 rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
1257 {
1258         struct rpcrdma_buffer *buffers = req->rl_buffer;
1259
1260         spin_lock(&buffers->rb_lock);
1261         req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1262         spin_unlock(&buffers->rb_lock);
1263 }
1264
1265 /*
1266  * Put reply buffers back into pool when not attached to
1267  * request. This happens in error conditions.
1268  */
1269 void
1270 rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
1271 {
1272         struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1273
1274         spin_lock(&buffers->rb_lock);
1275         buffers->rb_recv_count--;
1276         list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1277         spin_unlock(&buffers->rb_lock);
1278 }
1279
1280 /**
1281  * rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
1282  * @size: size of buffer to be allocated, in bytes
1283  * @direction: direction of data movement
1284  * @flags: GFP flags
1285  *
1286  * Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
1287  * can be persistently DMA-mapped for I/O.
1288  *
1289  * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1290  * receiving the payload of RDMA RECV operations. During Long Calls
1291  * or Replies they may be registered externally via ro_map.
1292  */
1293 struct rpcrdma_regbuf *
1294 rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
1295                      gfp_t flags)
1296 {
1297         struct rpcrdma_regbuf *rb;
1298
1299         rb = kmalloc(sizeof(*rb) + size, flags);
1300         if (rb == NULL)
1301                 return ERR_PTR(-ENOMEM);
1302
1303         rb->rg_device = NULL;
1304         rb->rg_direction = direction;
1305         rb->rg_iov.length = size;
1306
1307         return rb;
1308 }
1309
1310 /**
1311  * __rpcrdma_map_regbuf - DMA-map a regbuf
1312  * @ia: controlling rpcrdma_ia
1313  * @rb: regbuf to be mapped
1314  */
1315 bool
1316 __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
1317 {
1318         struct ib_device *device = ia->ri_device;
1319
1320         if (rb->rg_direction == DMA_NONE)
1321                 return false;
1322
1323         rb->rg_iov.addr = ib_dma_map_single(device,
1324                                             (void *)rb->rg_base,
1325                                             rdmab_length(rb),
1326                                             rb->rg_direction);
1327         if (ib_dma_mapping_error(device, rdmab_addr(rb)))
1328                 return false;
1329
1330         rb->rg_device = device;
1331         rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
1332         return true;
1333 }
1334
1335 static void
1336 rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb)
1337 {
1338         if (!rpcrdma_regbuf_is_mapped(rb))
1339                 return;
1340
1341         ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb),
1342                             rdmab_length(rb), rb->rg_direction);
1343         rb->rg_device = NULL;
1344 }
1345
1346 /**
1347  * rpcrdma_free_regbuf - deregister and free registered buffer
1348  * @rb: regbuf to be deregistered and freed
1349  */
1350 void
1351 rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
1352 {
1353         if (!rb)
1354                 return;
1355
1356         rpcrdma_dma_unmap_regbuf(rb);
1357         kfree(rb);
1358 }
1359
1360 /*
1361  * Prepost any receive buffer, then post send.
1362  *
1363  * Receive buffer is donated to hardware, reclaimed upon recv completion.
1364  */
1365 int
1366 rpcrdma_ep_post(struct rpcrdma_ia *ia,
1367                 struct rpcrdma_ep *ep,
1368                 struct rpcrdma_req *req)
1369 {
1370         struct ib_send_wr *send_wr = &req->rl_send_wr;
1371         struct ib_send_wr *send_wr_fail;
1372         int rc;
1373
1374         if (req->rl_reply) {
1375                 rc = rpcrdma_ep_post_recv(ia, req->rl_reply);
1376                 if (rc)
1377                         return rc;
1378                 req->rl_reply = NULL;
1379         }
1380
1381         dprintk("RPC:       %s: posting %d s/g entries\n",
1382                 __func__, send_wr->num_sge);
1383
1384         rpcrdma_set_signaled(ep, send_wr);
1385         rc = ib_post_send(ia->ri_id->qp, send_wr, &send_wr_fail);
1386         if (rc)
1387                 goto out_postsend_err;
1388         return 0;
1389
1390 out_postsend_err:
1391         pr_err("rpcrdma: RDMA Send ib_post_send returned %i\n", rc);
1392         return -ENOTCONN;
1393 }
1394
1395 int
1396 rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
1397                      struct rpcrdma_rep *rep)
1398 {
1399         struct ib_recv_wr *recv_wr_fail;
1400         int rc;
1401
1402         if (!rpcrdma_dma_map_regbuf(ia, rep->rr_rdmabuf))
1403                 goto out_map;
1404         rc = ib_post_recv(ia->ri_id->qp, &rep->rr_recv_wr, &recv_wr_fail);
1405         if (rc)
1406                 goto out_postrecv;
1407         return 0;
1408
1409 out_map:
1410         pr_err("rpcrdma: failed to DMA map the Receive buffer\n");
1411         return -EIO;
1412
1413 out_postrecv:
1414         pr_err("rpcrdma: ib_post_recv returned %i\n", rc);
1415         return -ENOTCONN;
1416 }
1417
1418 /**
1419  * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
1420  * @r_xprt: transport associated with these backchannel resources
1421  * @min_reqs: minimum number of incoming requests expected
1422  *
1423  * Returns zero if all requested buffers were posted, or a negative errno.
1424  */
1425 int
1426 rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
1427 {
1428         struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
1429         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
1430         struct rpcrdma_rep *rep;
1431         int rc;
1432
1433         while (count--) {
1434                 spin_lock(&buffers->rb_lock);
1435                 if (list_empty(&buffers->rb_recv_bufs))
1436                         goto out_reqbuf;
1437                 rep = rpcrdma_buffer_get_rep_locked(buffers);
1438                 spin_unlock(&buffers->rb_lock);
1439
1440                 rc = rpcrdma_ep_post_recv(ia, rep);
1441                 if (rc)
1442                         goto out_rc;
1443         }
1444
1445         return 0;
1446
1447 out_reqbuf:
1448         spin_unlock(&buffers->rb_lock);
1449         pr_warn("%s: no extra receive buffers\n", __func__);
1450         return -ENOMEM;
1451
1452 out_rc:
1453         rpcrdma_recv_buffer_put(rep);
1454         return rc;
1455 }