net/sunrpc/xprtrdma/transport.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  * transport.c
  42  *
  43  * This file contains the top-level implementation of an RPC RDMA
  44  * transport.
  45  *
  46  * Naming convention: functions beginning with xprt_ are part of the
  47  * transport switch. All others are RPC RDMA internal.
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/slab.h>
  52 #include <linux/seq_file.h>
  53 #include <linux/sunrpc/addr.h>
  54
  55 #include "xprt_rdma.h"
  56
  57 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  58 # define RPCDBG_FACILITY        RPCDBG_TRANS
  59 #endif
  60
  61 /*
  62  * tunables
  63  */
  64
  65 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  66 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  67 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  68 static unsigned int xprt_rdma_inline_write_padding;
  69 unsigned int xprt_rdma_memreg_strategy          = RPCRDMA_FRMR;
  70 int xprt_rdma_pad_optimize;
  71
  72 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  73
  74 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  75 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  76 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  77 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  78 static unsigned int zero;
  79 static unsigned int max_padding = PAGE_SIZE;
  80 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  81 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  82
  83 static struct ctl_table_header *sunrpc_table_header;
  84
  85 static struct ctl_table xr_tunables_table[] = {
  86         {
  87                 .procname       = "rdma_slot_table_entries",
  88                 .data           = &xprt_rdma_slot_table_entries,
  89                 .maxlen         = sizeof(unsigned int),
  90                 .mode           = 0644,
  91                 .proc_handler   = proc_dointvec_minmax,
  92                 .extra1         = &min_slot_table_size,
  93                 .extra2         = &max_slot_table_size
  94         },
  95         {
  96                 .procname       = "rdma_max_inline_read",
  97                 .data           = &xprt_rdma_max_inline_read,
  98                 .maxlen         = sizeof(unsigned int),
  99                 .mode           = 0644,
 100                 .proc_handler   = proc_dointvec_minmax,
 101                 .extra1         = &min_inline_size,
 102                 .extra2         = &max_inline_size,
 103         },
 104         {
 105                 .procname       = "rdma_max_inline_write",
 106                 .data           = &xprt_rdma_max_inline_write,
 107                 .maxlen         = sizeof(unsigned int),
 108                 .mode           = 0644,
 109                 .proc_handler   = proc_dointvec_minmax,
 110                 .extra1         = &min_inline_size,
 111                 .extra2         = &max_inline_size,
 112         },
 113         {
 114                 .procname       = "rdma_inline_write_padding",
 115                 .data           = &xprt_rdma_inline_write_padding,
 116                 .maxlen         = sizeof(unsigned int),
 117                 .mode           = 0644,
 118                 .proc_handler   = proc_dointvec_minmax,
 119                 .extra1         = &zero,
 120                 .extra2         = &max_padding,
 121         },
 122         {
 123                 .procname       = "rdma_memreg_strategy",
 124                 .data           = &xprt_rdma_memreg_strategy,
 125                 .maxlen         = sizeof(unsigned int),
 126                 .mode           = 0644,
 127                 .proc_handler   = proc_dointvec_minmax,
 128                 .extra1         = &min_memreg,
 129                 .extra2         = &max_memreg,
 130         },
 131         {
 132                 .procname       = "rdma_pad_optimize",
 133                 .data           = &xprt_rdma_pad_optimize,
 134                 .maxlen         = sizeof(unsigned int),
 135                 .mode           = 0644,
 136                 .proc_handler   = proc_dointvec,
 137         },
 138         { },
 139 };
 140
 141 static struct ctl_table sunrpc_table[] = {
 142         {
 143                 .procname       = "sunrpc",
 144                 .mode           = 0555,
 145                 .child          = xr_tunables_table
 146         },
 147         { },
 148 };
 149
 150 #endif
 151
 152 static const struct rpc_xprt_ops xprt_rdma_procs;
 153
 154 static void
 155 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 156 {
 157         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 158         char buf[20];
 159
 160         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 161         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 162
 163         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 164 }
 165
 166 static void
 167 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 168 {
 169         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 170         char buf[40];
 171
 172         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 173         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 174
 175         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 176 }
 177
 178 void
 179 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 180 {
 181         char buf[128];
 182
 183         switch (sap->sa_family) {
 184         case AF_INET:
 185                 xprt_rdma_format_addresses4(xprt, sap);
 186                 break;
 187         case AF_INET6:
 188                 xprt_rdma_format_addresses6(xprt, sap);
 189                 break;
 190         default:
 191                 pr_err("rpcrdma: Unrecognized address family\n");
 192                 return;
 193         }
 194
 195         (void)rpc_ntop(sap, buf, sizeof(buf));
 196         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 197
 198         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 199         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 200
 201         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 202         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 203
 204         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 205 }
 206
 207 void
 208 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 209 {
 210         unsigned int i;
 211
 212         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 213                 switch (i) {
 214                 case RPC_DISPLAY_PROTO:
 215                 case RPC_DISPLAY_NETID:
 216                         continue;
 217                 default:
 218                         kfree(xprt->address_strings[i]);
 219                 }
 220 }
 221
 222 void
 223 rpcrdma_conn_func(struct rpcrdma_ep *ep)
 224 {
 225         schedule_delayed_work(&ep->rep_connect_worker, 0);
 226 }
 227
 228 void
 229 rpcrdma_connect_worker(struct work_struct *work)
 230 {
 231         struct rpcrdma_ep *ep =
 232                 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
 233         struct rpcrdma_xprt *r_xprt =
 234                 container_of(ep, struct rpcrdma_xprt, rx_ep);
 235         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 236
 237         spin_lock_bh(&xprt->transport_lock);
 238         if (++xprt->connect_cookie == 0)        /* maintain a reserved value */
 239                 ++xprt->connect_cookie;
 240         if (ep->rep_connected > 0) {
 241                 if (!xprt_test_and_set_connected(xprt)) {
 242                         xprt->stat.connect_count++;
 243                         xprt->stat.connect_time += (long)jiffies -
 244                                                    xprt->stat.connect_start;
 245                         xprt_wake_pending_tasks(xprt, 0);
 246                 }
 247         } else {
 248                 if (xprt_test_and_clear_connected(xprt))
 249                         xprt_wake_pending_tasks(xprt, -ENOTCONN);
 250         }
 251         spin_unlock_bh(&xprt->transport_lock);
 252 }
 253
 254 static void
 255 xprt_rdma_connect_worker(struct work_struct *work)
 256 {
 257         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 258                                                    rx_connect_worker.work);
 259         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 260         int rc = 0;
 261
 262         xprt_clear_connected(xprt);
 263
 264         dprintk("RPC:       %s: %sconnect\n", __func__,
 265                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 266         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 267         if (rc)
 268                 xprt_wake_pending_tasks(xprt, rc);
 269
 270         dprintk("RPC:       %s: exit\n", __func__);
 271         xprt_clear_connecting(xprt);
 272 }
 273
 274 static void
 275 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 276 {
 277         struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
 278                                                    rx_xprt);
 279
 280         pr_info("rpcrdma: injecting transport disconnect on xprt=%p\n", xprt);
 281         rdma_disconnect(r_xprt->rx_ia.ri_id);
 282 }
 283
 284 /*
 285  * xprt_rdma_destroy
 286  *
 287  * Destroy the xprt.
 288  * Free all memory associated with the object, including its own.
 289  * NOTE: none of the *destroy methods free memory for their top-level
 290  * objects, even though they may have allocated it (they do free
 291  * private memory). It's up to the caller to handle it. In this
 292  * case (RDMA transport), all structure memory is inlined with the
 293  * struct rpcrdma_xprt.
 294  */
 295 static void
 296 xprt_rdma_destroy(struct rpc_xprt *xprt)
 297 {
 298         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 299
 300         dprintk("RPC:       %s: called\n", __func__);
 301
 302         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 303
 304         xprt_clear_connected(xprt);
 305
 306         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 307         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 308         rpcrdma_ia_close(&r_xprt->rx_ia);
 309
 310         xprt_rdma_free_addresses(xprt);
 311
 312         xprt_free(xprt);
 313
 314         dprintk("RPC:       %s: returning\n", __func__);
 315
 316         module_put(THIS_MODULE);
 317 }
 318
 319 static const struct rpc_timeout xprt_rdma_default_timeout = {
 320         .to_initval = 60 * HZ,
 321         .to_maxval = 60 * HZ,
 322 };
 323
 324 /**
 325  * xprt_setup_rdma - Set up transport to use RDMA
 326  *
 327  * @args: rpc transport arguments
 328  */
 329 static struct rpc_xprt *
 330 xprt_setup_rdma(struct xprt_create *args)
 331 {
 332         struct rpcrdma_create_data_internal cdata;
 333         struct rpc_xprt *xprt;
 334         struct rpcrdma_xprt *new_xprt;
 335         struct rpcrdma_ep *new_ep;
 336         struct sockaddr *sap;
 337         int rc;
 338
 339         if (args->addrlen > sizeof(xprt->addr)) {
 340                 dprintk("RPC:       %s: address too large\n", __func__);
 341                 return ERR_PTR(-EBADF);
 342         }
 343
 344         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 345                         xprt_rdma_slot_table_entries,
 346                         xprt_rdma_slot_table_entries);
 347         if (xprt == NULL) {
 348                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 349                         __func__);
 350                 return ERR_PTR(-ENOMEM);
 351         }
 352
 353         /* 60 second timeout, no retries */
 354         xprt->timeout = &xprt_rdma_default_timeout;
 355         xprt->bind_timeout = RPCRDMA_BIND_TO;
 356         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 357         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 358
 359         xprt->resvport = 0;             /* privileged port not needed */
 360         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 361         xprt->ops = &xprt_rdma_procs;
 362
 363         /*
 364          * Set up RDMA-specific connect data.
 365          */
 366
 367         sap = (struct sockaddr *)&cdata.addr;
 368         memcpy(sap, args->dstaddr, args->addrlen);
 369
 370         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 371          * address, for any side protocols which peek at it */
 372         xprt->prot = IPPROTO_TCP;
 373         xprt->addrlen = args->addrlen;
 374         memcpy(&xprt->addr, sap, xprt->addrlen);
 375
 376         if (rpc_get_port(sap))
 377                 xprt_set_bound(xprt);
 378
 379         cdata.max_requests = xprt->max_reqs;
 380
 381         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 382         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 383
 384         cdata.inline_wsize = xprt_rdma_max_inline_write;
 385         if (cdata.inline_wsize > cdata.wsize)
 386                 cdata.inline_wsize = cdata.wsize;
 387
 388         cdata.inline_rsize = xprt_rdma_max_inline_read;
 389         if (cdata.inline_rsize > cdata.rsize)
 390                 cdata.inline_rsize = cdata.rsize;
 391
 392         cdata.padding = xprt_rdma_inline_write_padding;
 393
 394         /*
 395          * Create new transport instance, which includes initialized
 396          *  o ia
 397          *  o endpoint
 398          *  o buffers
 399          */
 400
 401         new_xprt = rpcx_to_rdmax(xprt);
 402
 403         rc = rpcrdma_ia_open(new_xprt, sap);
 404         if (rc)
 405                 goto out1;
 406
 407         /*
 408          * initialize and create ep
 409          */
 410         new_xprt->rx_data = cdata;
 411         new_ep = &new_xprt->rx_ep;
 412         new_ep->rep_remote_addr = cdata.addr;
 413
 414         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 415                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 416         if (rc)
 417                 goto out2;
 418
 419         /*
 420          * Allocate pre-registered send and receive buffers for headers and
 421          * any inline data. Also specify any padding which will be provided
 422          * from a preregistered zero buffer.
 423          */
 424         rc = rpcrdma_buffer_create(new_xprt);
 425         if (rc)
 426                 goto out3;
 427
 428         /*
 429          * Register a callback for connection events. This is necessary because
 430          * connection loss notification is async. We also catch connection loss
 431          * when reaping receives.
 432          */
 433         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 434                           xprt_rdma_connect_worker);
 435
 436         xprt_rdma_format_addresses(xprt, sap);
 437         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 438         if (xprt->max_payload == 0)
 439                 goto out4;
 440         xprt->max_payload <<= PAGE_SHIFT;
 441         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 442                 __func__, xprt->max_payload);
 443
 444         if (!try_module_get(THIS_MODULE))
 445                 goto out4;
 446
 447         dprintk("RPC:       %s: %s:%s\n", __func__,
 448                 xprt->address_strings[RPC_DISPLAY_ADDR],
 449                 xprt->address_strings[RPC_DISPLAY_PORT]);
 450         return xprt;
 451
 452 out4:
 453         xprt_rdma_free_addresses(xprt);
 454         rc = -EINVAL;
 455 out3:
 456         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 457 out2:
 458         rpcrdma_ia_close(&new_xprt->rx_ia);
 459 out1:
 460         xprt_free(xprt);
 461         return ERR_PTR(rc);
 462 }
 463
 464 /**
 465  * xprt_rdma_close - Close down RDMA connection
 466  * @xprt: generic transport to be closed
 467  *
 468  * Called during transport shutdown reconnect, or device
 469  * removal. Caller holds the transport's write lock.
 470  */
 471 static void
 472 xprt_rdma_close(struct rpc_xprt *xprt)
 473 {
 474         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 475         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 476         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 477
 478         dprintk("RPC:       %s: closing xprt %p\n", __func__, xprt);
 479
 480         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 481                 xprt_clear_connected(xprt);
 482                 rpcrdma_ia_remove(ia);
 483                 return;
 484         }
 485         if (ep->rep_connected == -ENODEV)
 486                 return;
 487         if (ep->rep_connected > 0)
 488                 xprt->reestablish_timeout = 0;
 489         xprt_disconnect_done(xprt);
 490         rpcrdma_ep_disconnect(ep, ia);
 491 }
 492
 493 static void
 494 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 495 {
 496         struct sockaddr_in *sap;
 497
 498         sap = (struct sockaddr_in *)&xprt->addr;
 499         sap->sin_port = htons(port);
 500         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 501         sap->sin_port = htons(port);
 502         dprintk("RPC:       %s: %u\n", __func__, port);
 503 }
 504
 505 /**
 506  * xprt_rdma_timer - invoked when an RPC times out
 507  * @xprt: controlling RPC transport
 508  * @task: RPC task that timed out
 509  *
 510  * Invoked when the transport is still connected, but an RPC
 511  * retransmit timeout occurs.
 512  *
 513  * Since RDMA connections don't have a keep-alive, forcibly
 514  * disconnect and retry to connect. This drives full
 515  * detection of the network path, and retransmissions of
 516  * all pending RPCs.
 517  */
 518 static void
 519 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 520 {
 521         dprintk("RPC: %5u %s: xprt = %p\n", task->tk_pid, __func__, xprt);
 522
 523         xprt_force_disconnect(xprt);
 524 }
 525
 526 static void
 527 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 528 {
 529         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 530
 531         if (r_xprt->rx_ep.rep_connected != 0) {
 532                 /* Reconnect */
 533                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 534                                       xprt->reestablish_timeout);
 535                 xprt->reestablish_timeout <<= 1;
 536                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 537                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 538                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 539                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 540         } else {
 541                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 542                 if (!RPC_IS_ASYNC(task))
 543                         flush_delayed_work(&r_xprt->rx_connect_worker);
 544         }
 545 }
 546
 547 /* Allocate a fixed-size buffer in which to construct and send the
 548  * RPC-over-RDMA header for this request.
 549  */
 550 static bool
 551 rpcrdma_get_rdmabuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 552                     gfp_t flags)
 553 {
 554         size_t size = RPCRDMA_HDRBUF_SIZE;
 555         struct rpcrdma_regbuf *rb;
 556
 557         if (req->rl_rdmabuf)
 558                 return true;
 559
 560         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 561         if (IS_ERR(rb))
 562                 return false;
 563
 564         r_xprt->rx_stats.hardway_register_count += size;
 565         req->rl_rdmabuf = rb;
 566         xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
 567         return true;
 568 }
 569
 570 static bool
 571 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 572                     size_t size, gfp_t flags)
 573 {
 574         struct rpcrdma_regbuf *rb;
 575
 576         if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
 577                 return true;
 578
 579         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 580         if (IS_ERR(rb))
 581                 return false;
 582
 583         rpcrdma_free_regbuf(req->rl_sendbuf);
 584         r_xprt->rx_stats.hardway_register_count += size;
 585         req->rl_sendbuf = rb;
 586         return true;
 587 }
 588
 589 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
 590  * The decision to use a Reply chunk is made later in
 591  * rpcrdma_marshal_req. This buffer is registered at that time.
 592  *
 593  * Otherwise, the associated RPC Reply arrives in a separate
 594  * Receive buffer, arbitrarily chosen by the HCA. The buffer
 595  * allocated here for the RPC Reply is not utilized in that
 596  * case. See rpcrdma_inline_fixup.
 597  *
 598  * A regbuf is used here to remember the buffer size.
 599  */
 600 static bool
 601 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 602                     size_t size, gfp_t flags)
 603 {
 604         struct rpcrdma_regbuf *rb;
 605
 606         if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
 607                 return true;
 608
 609         rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
 610         if (IS_ERR(rb))
 611                 return false;
 612
 613         rpcrdma_free_regbuf(req->rl_recvbuf);
 614         r_xprt->rx_stats.hardway_register_count += size;
 615         req->rl_recvbuf = rb;
 616         return true;
 617 }
 618
 619 /**
 620  * xprt_rdma_allocate - allocate transport resources for an RPC
 621  * @task: RPC task
 622  *
 623  * Return values:
 624  *        0:    Success; rq_buffer points to RPC buffer to use
 625  *   ENOMEM:    Out of memory, call again later
 626  *      EIO:    A permanent error occurred, do not retry
 627  *
 628  * The RDMA allocate/free functions need the task structure as a place
 629  * to hide the struct rpcrdma_req, which is necessary for the actual
 630  * send/recv sequence.
 631  *
 632  * xprt_rdma_allocate provides buffers that are already mapped for
 633  * DMA, and a local DMA lkey is provided for each.
 634  */
 635 static int
 636 xprt_rdma_allocate(struct rpc_task *task)
 637 {
 638         struct rpc_rqst *rqst = task->tk_rqstp;
 639         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 640         struct rpcrdma_req *req;
 641         gfp_t flags;
 642
 643         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 644         if (req == NULL)
 645                 return -ENOMEM;
 646
 647         flags = RPCRDMA_DEF_GFP;
 648         if (RPC_IS_ASYNC(task))
 649                 flags = GFP_NOWAIT | __GFP_NOWARN;
 650         if (RPC_IS_SWAPPER(task))
 651                 flags |= __GFP_MEMALLOC;
 652
 653         if (!rpcrdma_get_rdmabuf(r_xprt, req, flags))
 654                 goto out_fail;
 655         if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
 656                 goto out_fail;
 657         if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
 658                 goto out_fail;
 659
 660         dprintk("RPC: %5u %s: send size = %zd, recv size = %zd, req = %p\n",
 661                 task->tk_pid, __func__, rqst->rq_callsize,
 662                 rqst->rq_rcvsize, req);
 663
 664         req->rl_connect_cookie = 0;     /* our reserved value */
 665         rpcrdma_set_xprtdata(rqst, req);
 666         rqst->rq_buffer = req->rl_sendbuf->rg_base;
 667         rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
 668         return 0;
 669
 670 out_fail:
 671         rpcrdma_buffer_put(req);
 672         return -ENOMEM;
 673 }
 674
 675 /**
 676  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 677  * @task: RPC task
 678  *
 679  * Caller guarantees rqst->rq_buffer is non-NULL.
 680  */
 681 static void
 682 xprt_rdma_free(struct rpc_task *task)
 683 {
 684         struct rpc_rqst *rqst = task->tk_rqstp;
 685         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 686         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 687         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 688
 689         if (req->rl_backchannel)
 690                 return;
 691
 692         dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 693
 694         if (!list_empty(&req->rl_registered))
 695                 ia->ri_ops->ro_unmap_sync(r_xprt, &req->rl_registered);
 696         rpcrdma_unmap_sges(ia, req);
 697         rpcrdma_buffer_put(req);
 698 }
 699
 700 /**
 701  * xprt_rdma_send_request - marshal and send an RPC request
 702  * @task: RPC task with an RPC message in rq_snd_buf
 703  *
 704  * Caller holds the transport's write lock.
 705  *
 706  * Return values:
 707  *        0:    The request has been sent
 708  * ENOTCONN:    Caller needs to invoke connect logic then call again
 709  *  ENOBUFS:    Call again later to send the request
 710  *      EIO:    A permanent error occurred. The request was not sent,
 711  *              and don't try it again
 712  *
 713  * send_request invokes the meat of RPC RDMA. It must do the following:
 714  *
 715  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 716  *      putting a header in front of data, and creating IOVs for RDMA
 717  *      from those in the request.
 718  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 719  *  3.  Post a recv message to set up asynch completion, then send
 720  *      the request (rpcrdma_ep_post).
 721  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 722  */
 723 static int
 724 xprt_rdma_send_request(struct rpc_task *task)
 725 {
 726         struct rpc_rqst *rqst = task->tk_rqstp;
 727         struct rpc_xprt *xprt = rqst->rq_xprt;
 728         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 729         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 730         int rc = 0;
 731
 732         if (!xprt_connected(xprt))
 733                 goto drop_connection;
 734
 735         /* On retransmit, remove any previously registered chunks */
 736         if (unlikely(!list_empty(&req->rl_registered)))
 737                 r_xprt->rx_ia.ri_ops->ro_unmap_safe(r_xprt, req, false);
 738
 739         rc = rpcrdma_marshal_req(r_xprt, rqst);
 740         if (rc < 0)
 741                 goto failed_marshal;
 742
 743         if (req->rl_reply == NULL)              /* e.g. reconnection */
 744                 rpcrdma_recv_buffer_get(req);
 745
 746         /* Must suppress retransmit to maintain credits */
 747         if (req->rl_connect_cookie == xprt->connect_cookie)
 748                 goto drop_connection;
 749         req->rl_connect_cookie = xprt->connect_cookie;
 750
 751         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 752                 goto drop_connection;
 753
 754         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 755         rqst->rq_bytes_sent = 0;
 756         return 0;
 757
 758 failed_marshal:
 759         if (rc != -ENOTCONN)
 760                 return rc;
 761 drop_connection:
 762         xprt_disconnect_done(xprt);
 763         return -ENOTCONN;       /* implies disconnect */
 764 }
 765
 766 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 767 {
 768         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 769         long idle_time = 0;
 770
 771         if (xprt_connected(xprt))
 772                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 773
 774         seq_puts(seq, "\txprt:\trdma ");
 775         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 776                    0,   /* need a local port? */
 777                    xprt->stat.bind_count,
 778                    xprt->stat.connect_count,
 779                    xprt->stat.connect_time,
 780                    idle_time,
 781                    xprt->stat.sends,
 782                    xprt->stat.recvs,
 783                    xprt->stat.bad_xids,
 784                    xprt->stat.req_u,
 785                    xprt->stat.bklog_u);
 786         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 787                    r_xprt->rx_stats.read_chunk_count,
 788                    r_xprt->rx_stats.write_chunk_count,
 789                    r_xprt->rx_stats.reply_chunk_count,
 790                    r_xprt->rx_stats.total_rdma_request,
 791                    r_xprt->rx_stats.total_rdma_reply,
 792                    r_xprt->rx_stats.pullup_copy_count,
 793                    r_xprt->rx_stats.fixup_copy_count,
 794                    r_xprt->rx_stats.hardway_register_count,
 795                    r_xprt->rx_stats.failed_marshal_count,
 796                    r_xprt->rx_stats.bad_reply_count,
 797                    r_xprt->rx_stats.nomsg_call_count);
 798         seq_printf(seq, "%lu %lu %lu %lu\n",
 799                    r_xprt->rx_stats.mrs_recovered,
 800                    r_xprt->rx_stats.mrs_orphaned,
 801                    r_xprt->rx_stats.mrs_allocated,
 802                    r_xprt->rx_stats.local_inv_needed);
 803 }
 804
 805 static int
 806 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 807 {
 808         return 0;
 809 }
 810
 811 static void
 812 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 813 {
 814 }
 815
 816 /*
 817  * Plumbing for rpc transport switch and kernel module
 818  */
 819
 820 static const struct rpc_xprt_ops xprt_rdma_procs = {
 821         .reserve_xprt           = xprt_reserve_xprt_cong,
 822         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 823         .alloc_slot             = xprt_alloc_slot,
 824         .release_request        = xprt_release_rqst_cong,       /* ditto */
 825         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 826         .timer                  = xprt_rdma_timer,
 827         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 828         .set_port               = xprt_rdma_set_port,
 829         .connect                = xprt_rdma_connect,
 830         .buf_alloc              = xprt_rdma_allocate,
 831         .buf_free               = xprt_rdma_free,
 832         .send_request           = xprt_rdma_send_request,
 833         .close                  = xprt_rdma_close,
 834         .destroy                = xprt_rdma_destroy,
 835         .print_stats            = xprt_rdma_print_stats,
 836         .enable_swap            = xprt_rdma_enable_swap,
 837         .disable_swap           = xprt_rdma_disable_swap,
 838         .inject_disconnect      = xprt_rdma_inject_disconnect,
 839 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 840         .bc_setup               = xprt_rdma_bc_setup,
 841         .bc_up                  = xprt_rdma_bc_up,
 842         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 843         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 844         .bc_destroy             = xprt_rdma_bc_destroy,
 845 #endif
 846 };
 847
 848 static struct xprt_class xprt_rdma = {
 849         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 850         .name                   = "rdma",
 851         .owner                  = THIS_MODULE,
 852         .ident                  = XPRT_TRANSPORT_RDMA,
 853         .setup                  = xprt_setup_rdma,
 854         .netid                  = { "rdma", "rdma6", "" },
 855 };
 856
 857 void xprt_rdma_cleanup(void)
 858 {
 859         int rc;
 860
 861         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 862 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 863         if (sunrpc_table_header) {
 864                 unregister_sysctl_table(sunrpc_table_header);
 865                 sunrpc_table_header = NULL;
 866         }
 867 #endif
 868         rc = xprt_unregister_transport(&xprt_rdma);
 869         if (rc)
 870                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 871                         __func__, rc);
 872
 873         rpcrdma_destroy_wq();
 874
 875         rc = xprt_unregister_transport(&xprt_rdma_bc);
 876         if (rc)
 877                 dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
 878                         __func__, rc);
 879 }
 880
 881 int xprt_rdma_init(void)
 882 {
 883         int rc;
 884
 885         rc = rpcrdma_alloc_wq();
 886         if (rc)
 887                 return rc;
 888
 889         rc = xprt_register_transport(&xprt_rdma);
 890         if (rc) {
 891                 rpcrdma_destroy_wq();
 892                 return rc;
 893         }
 894
 895         rc = xprt_register_transport(&xprt_rdma_bc);
 896         if (rc) {
 897                 xprt_unregister_transport(&xprt_rdma);
 898                 rpcrdma_destroy_wq();
 899                 return rc;
 900         }
 901
 902         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 903
 904         dprintk("Defaults:\n");
 905         dprintk("\tSlots %d\n"
 906                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 907                 xprt_rdma_slot_table_entries,
 908                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 909         dprintk("\tPadding %d\n\tMemreg %d\n",
 910                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 911
 912 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 913         if (!sunrpc_table_header)
 914                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 915 #endif
 916         return 0;
 917 }