net/sunrpc/xprtrdma/transport.c

   1 /*
   2  * Copyright (c) 2014-2017 Oracle.  All rights reserved.
   3  * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the BSD-type
   9  * license below:
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  *
  15  *      Redistributions of source code must retain the above copyright
  16  *      notice, this list of conditions and the following disclaimer.
  17  *
  18  *      Redistributions in binary form must reproduce the above
  19  *      copyright notice, this list of conditions and the following
  20  *      disclaimer in the documentation and/or other materials provided
  21  *      with the distribution.
  22  *
  23  *      Neither the name of the Network Appliance, Inc. nor the names of
  24  *      its contributors may be used to endorse or promote products
  25  *      derived from this software without specific prior written
  26  *      permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 /*
  42  * transport.c
  43  *
  44  * This file contains the top-level implementation of an RPC RDMA
  45  * transport.
  46  *
  47  * Naming convention: functions beginning with xprt_ are part of the
  48  * transport switch. All others are RPC RDMA internal.
  49  */
  50
  51 #include <linux/module.h>
  52 #include <linux/slab.h>
  53 #include <linux/seq_file.h>
  54 #include <linux/sunrpc/addr.h>
  55 #include <linux/smp.h>
  56
  57 #include "xprt_rdma.h"
  58
  59 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  60 # define RPCDBG_FACILITY        RPCDBG_TRANS
  61 #endif
  62
  63 /*
  64  * tunables
  65  */
  66
  67 static unsigned int xprt_rdma_slot_table_entries = RPCRDMA_DEF_SLOT_TABLE;
  68 unsigned int xprt_rdma_max_inline_read = RPCRDMA_DEF_INLINE;
  69 static unsigned int xprt_rdma_max_inline_write = RPCRDMA_DEF_INLINE;
  70 static unsigned int xprt_rdma_inline_write_padding;
  71 unsigned int xprt_rdma_memreg_strategy          = RPCRDMA_FRMR;
  72 int xprt_rdma_pad_optimize;
  73
  74 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  75
  76 static unsigned int min_slot_table_size = RPCRDMA_MIN_SLOT_TABLE;
  77 static unsigned int max_slot_table_size = RPCRDMA_MAX_SLOT_TABLE;
  78 static unsigned int min_inline_size = RPCRDMA_MIN_INLINE;
  79 static unsigned int max_inline_size = RPCRDMA_MAX_INLINE;
  80 static unsigned int zero;
  81 static unsigned int max_padding = PAGE_SIZE;
  82 static unsigned int min_memreg = RPCRDMA_BOUNCEBUFFERS;
  83 static unsigned int max_memreg = RPCRDMA_LAST - 1;
  84
  85 static struct ctl_table_header *sunrpc_table_header;
  86
  87 static struct ctl_table xr_tunables_table[] = {
  88         {
  89                 .procname       = "rdma_slot_table_entries",
  90                 .data           = &xprt_rdma_slot_table_entries,
  91                 .maxlen         = sizeof(unsigned int),
  92                 .mode           = 0644,
  93                 .proc_handler   = proc_dointvec_minmax,
  94                 .extra1         = &min_slot_table_size,
  95                 .extra2         = &max_slot_table_size
  96         },
  97         {
  98                 .procname       = "rdma_max_inline_read",
  99                 .data           = &xprt_rdma_max_inline_read,
 100                 .maxlen         = sizeof(unsigned int),
 101                 .mode           = 0644,
 102                 .proc_handler   = proc_dointvec_minmax,
 103                 .extra1         = &min_inline_size,
 104                 .extra2         = &max_inline_size,
 105         },
 106         {
 107                 .procname       = "rdma_max_inline_write",
 108                 .data           = &xprt_rdma_max_inline_write,
 109                 .maxlen         = sizeof(unsigned int),
 110                 .mode           = 0644,
 111                 .proc_handler   = proc_dointvec_minmax,
 112                 .extra1         = &min_inline_size,
 113                 .extra2         = &max_inline_size,
 114         },
 115         {
 116                 .procname       = "rdma_inline_write_padding",
 117                 .data           = &xprt_rdma_inline_write_padding,
 118                 .maxlen         = sizeof(unsigned int),
 119                 .mode           = 0644,
 120                 .proc_handler   = proc_dointvec_minmax,
 121                 .extra1         = &zero,
 122                 .extra2         = &max_padding,
 123         },
 124         {
 125                 .procname       = "rdma_memreg_strategy",
 126                 .data           = &xprt_rdma_memreg_strategy,
 127                 .maxlen         = sizeof(unsigned int),
 128                 .mode           = 0644,
 129                 .proc_handler   = proc_dointvec_minmax,
 130                 .extra1         = &min_memreg,
 131                 .extra2         = &max_memreg,
 132         },
 133         {
 134                 .procname       = "rdma_pad_optimize",
 135                 .data           = &xprt_rdma_pad_optimize,
 136                 .maxlen         = sizeof(unsigned int),
 137                 .mode           = 0644,
 138                 .proc_handler   = proc_dointvec,
 139         },
 140         { },
 141 };
 142
 143 static struct ctl_table sunrpc_table[] = {
 144         {
 145                 .procname       = "sunrpc",
 146                 .mode           = 0555,
 147                 .child          = xr_tunables_table
 148         },
 149         { },
 150 };
 151
 152 #endif
 153
 154 static const struct rpc_xprt_ops xprt_rdma_procs;
 155
 156 static void
 157 xprt_rdma_format_addresses4(struct rpc_xprt *xprt, struct sockaddr *sap)
 158 {
 159         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 160         char buf[20];
 161
 162         snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 163         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 164
 165         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA;
 166 }
 167
 168 static void
 169 xprt_rdma_format_addresses6(struct rpc_xprt *xprt, struct sockaddr *sap)
 170 {
 171         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 172         char buf[40];
 173
 174         snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 175         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 176
 177         xprt->address_strings[RPC_DISPLAY_NETID] = RPCBIND_NETID_RDMA6;
 178 }
 179
 180 void
 181 xprt_rdma_format_addresses(struct rpc_xprt *xprt, struct sockaddr *sap)
 182 {
 183         char buf[128];
 184
 185         switch (sap->sa_family) {
 186         case AF_INET:
 187                 xprt_rdma_format_addresses4(xprt, sap);
 188                 break;
 189         case AF_INET6:
 190                 xprt_rdma_format_addresses6(xprt, sap);
 191                 break;
 192         default:
 193                 pr_err("rpcrdma: Unrecognized address family\n");
 194                 return;
 195         }
 196
 197         (void)rpc_ntop(sap, buf, sizeof(buf));
 198         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 199
 200         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 201         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 202
 203         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 204         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 205
 206         xprt->address_strings[RPC_DISPLAY_PROTO] = "rdma";
 207 }
 208
 209 void
 210 xprt_rdma_free_addresses(struct rpc_xprt *xprt)
 211 {
 212         unsigned int i;
 213
 214         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 215                 switch (i) {
 216                 case RPC_DISPLAY_PROTO:
 217                 case RPC_DISPLAY_NETID:
 218                         continue;
 219                 default:
 220                         kfree(xprt->address_strings[i]);
 221                 }
 222 }
 223
 224 void
 225 rpcrdma_conn_func(struct rpcrdma_ep *ep)
 226 {
 227         schedule_delayed_work(&ep->rep_connect_worker, 0);
 228 }
 229
 230 void
 231 rpcrdma_connect_worker(struct work_struct *work)
 232 {
 233         struct rpcrdma_ep *ep =
 234                 container_of(work, struct rpcrdma_ep, rep_connect_worker.work);
 235         struct rpcrdma_xprt *r_xprt =
 236                 container_of(ep, struct rpcrdma_xprt, rx_ep);
 237         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 238
 239         spin_lock_bh(&xprt->transport_lock);
 240         if (++xprt->connect_cookie == 0)        /* maintain a reserved value */
 241                 ++xprt->connect_cookie;
 242         if (ep->rep_connected > 0) {
 243                 if (!xprt_test_and_set_connected(xprt))
 244                         xprt_wake_pending_tasks(xprt, 0);
 245         } else {
 246                 if (xprt_test_and_clear_connected(xprt))
 247                         xprt_wake_pending_tasks(xprt, -ENOTCONN);
 248         }
 249         spin_unlock_bh(&xprt->transport_lock);
 250 }
 251
 252 static void
 253 xprt_rdma_connect_worker(struct work_struct *work)
 254 {
 255         struct rpcrdma_xprt *r_xprt = container_of(work, struct rpcrdma_xprt,
 256                                                    rx_connect_worker.work);
 257         struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 258         int rc = 0;
 259
 260         xprt_clear_connected(xprt);
 261
 262         dprintk("RPC:       %s: %sconnect\n", __func__,
 263                         r_xprt->rx_ep.rep_connected != 0 ? "re" : "");
 264         rc = rpcrdma_ep_connect(&r_xprt->rx_ep, &r_xprt->rx_ia);
 265         if (rc)
 266                 xprt_wake_pending_tasks(xprt, rc);
 267
 268         dprintk("RPC:       %s: exit\n", __func__);
 269         xprt_clear_connecting(xprt);
 270 }
 271
 272 static void
 273 xprt_rdma_inject_disconnect(struct rpc_xprt *xprt)
 274 {
 275         struct rpcrdma_xprt *r_xprt = container_of(xprt, struct rpcrdma_xprt,
 276                                                    rx_xprt);
 277
 278         pr_info("rpcrdma: injecting transport disconnect on xprt=%p\n", xprt);
 279         rdma_disconnect(r_xprt->rx_ia.ri_id);
 280 }
 281
 282 /*
 283  * xprt_rdma_destroy
 284  *
 285  * Destroy the xprt.
 286  * Free all memory associated with the object, including its own.
 287  * NOTE: none of the *destroy methods free memory for their top-level
 288  * objects, even though they may have allocated it (they do free
 289  * private memory). It's up to the caller to handle it. In this
 290  * case (RDMA transport), all structure memory is inlined with the
 291  * struct rpcrdma_xprt.
 292  */
 293 static void
 294 xprt_rdma_destroy(struct rpc_xprt *xprt)
 295 {
 296         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 297
 298         dprintk("RPC:       %s: called\n", __func__);
 299
 300         cancel_delayed_work_sync(&r_xprt->rx_connect_worker);
 301
 302         xprt_clear_connected(xprt);
 303
 304         rpcrdma_ep_destroy(&r_xprt->rx_ep, &r_xprt->rx_ia);
 305         rpcrdma_buffer_destroy(&r_xprt->rx_buf);
 306         rpcrdma_ia_close(&r_xprt->rx_ia);
 307
 308         xprt_rdma_free_addresses(xprt);
 309
 310         xprt_free(xprt);
 311
 312         dprintk("RPC:       %s: returning\n", __func__);
 313
 314         module_put(THIS_MODULE);
 315 }
 316
 317 static const struct rpc_timeout xprt_rdma_default_timeout = {
 318         .to_initval = 60 * HZ,
 319         .to_maxval = 60 * HZ,
 320 };
 321
 322 /**
 323  * xprt_setup_rdma - Set up transport to use RDMA
 324  *
 325  * @args: rpc transport arguments
 326  */
 327 static struct rpc_xprt *
 328 xprt_setup_rdma(struct xprt_create *args)
 329 {
 330         struct rpcrdma_create_data_internal cdata;
 331         struct rpc_xprt *xprt;
 332         struct rpcrdma_xprt *new_xprt;
 333         struct rpcrdma_ep *new_ep;
 334         struct sockaddr *sap;
 335         int rc;
 336
 337         if (args->addrlen > sizeof(xprt->addr)) {
 338                 dprintk("RPC:       %s: address too large\n", __func__);
 339                 return ERR_PTR(-EBADF);
 340         }
 341
 342         xprt = xprt_alloc(args->net, sizeof(struct rpcrdma_xprt),
 343                         xprt_rdma_slot_table_entries,
 344                         xprt_rdma_slot_table_entries);
 345         if (xprt == NULL) {
 346                 dprintk("RPC:       %s: couldn't allocate rpcrdma_xprt\n",
 347                         __func__);
 348                 return ERR_PTR(-ENOMEM);
 349         }
 350
 351         /* 60 second timeout, no retries */
 352         xprt->timeout = &xprt_rdma_default_timeout;
 353         xprt->bind_timeout = RPCRDMA_BIND_TO;
 354         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 355         xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO;
 356
 357         xprt->resvport = 0;             /* privileged port not needed */
 358         xprt->tsh_size = 0;             /* RPC-RDMA handles framing */
 359         xprt->ops = &xprt_rdma_procs;
 360
 361         /*
 362          * Set up RDMA-specific connect data.
 363          */
 364
 365         sap = (struct sockaddr *)&cdata.addr;
 366         memcpy(sap, args->dstaddr, args->addrlen);
 367
 368         /* Ensure xprt->addr holds valid server TCP (not RDMA)
 369          * address, for any side protocols which peek at it */
 370         xprt->prot = IPPROTO_TCP;
 371         xprt->addrlen = args->addrlen;
 372         memcpy(&xprt->addr, sap, xprt->addrlen);
 373
 374         if (rpc_get_port(sap))
 375                 xprt_set_bound(xprt);
 376
 377         cdata.max_requests = xprt->max_reqs;
 378
 379         cdata.rsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA write max */
 380         cdata.wsize = RPCRDMA_MAX_SEGS * PAGE_SIZE; /* RDMA read max */
 381
 382         cdata.inline_wsize = xprt_rdma_max_inline_write;
 383         if (cdata.inline_wsize > cdata.wsize)
 384                 cdata.inline_wsize = cdata.wsize;
 385
 386         cdata.inline_rsize = xprt_rdma_max_inline_read;
 387         if (cdata.inline_rsize > cdata.rsize)
 388                 cdata.inline_rsize = cdata.rsize;
 389
 390         cdata.padding = xprt_rdma_inline_write_padding;
 391
 392         /*
 393          * Create new transport instance, which includes initialized
 394          *  o ia
 395          *  o endpoint
 396          *  o buffers
 397          */
 398
 399         new_xprt = rpcx_to_rdmax(xprt);
 400
 401         rc = rpcrdma_ia_open(new_xprt, sap);
 402         if (rc)
 403                 goto out1;
 404
 405         /*
 406          * initialize and create ep
 407          */
 408         new_xprt->rx_data = cdata;
 409         new_ep = &new_xprt->rx_ep;
 410         new_ep->rep_remote_addr = cdata.addr;
 411
 412         rc = rpcrdma_ep_create(&new_xprt->rx_ep,
 413                                 &new_xprt->rx_ia, &new_xprt->rx_data);
 414         if (rc)
 415                 goto out2;
 416
 417         /*
 418          * Allocate pre-registered send and receive buffers for headers and
 419          * any inline data. Also specify any padding which will be provided
 420          * from a preregistered zero buffer.
 421          */
 422         rc = rpcrdma_buffer_create(new_xprt);
 423         if (rc)
 424                 goto out3;
 425
 426         /*
 427          * Register a callback for connection events. This is necessary because
 428          * connection loss notification is async. We also catch connection loss
 429          * when reaping receives.
 430          */
 431         INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
 432                           xprt_rdma_connect_worker);
 433
 434         xprt_rdma_format_addresses(xprt, sap);
 435         xprt->max_payload = new_xprt->rx_ia.ri_ops->ro_maxpages(new_xprt);
 436         if (xprt->max_payload == 0)
 437                 goto out4;
 438         xprt->max_payload <<= PAGE_SHIFT;
 439         dprintk("RPC:       %s: transport data payload maximum: %zu bytes\n",
 440                 __func__, xprt->max_payload);
 441
 442         if (!try_module_get(THIS_MODULE))
 443                 goto out4;
 444
 445         dprintk("RPC:       %s: %s:%s\n", __func__,
 446                 xprt->address_strings[RPC_DISPLAY_ADDR],
 447                 xprt->address_strings[RPC_DISPLAY_PORT]);
 448         return xprt;
 449
 450 out4:
 451         xprt_rdma_free_addresses(xprt);
 452         rc = -EINVAL;
 453 out3:
 454         rpcrdma_ep_destroy(new_ep, &new_xprt->rx_ia);
 455 out2:
 456         rpcrdma_ia_close(&new_xprt->rx_ia);
 457 out1:
 458         xprt_free(xprt);
 459         return ERR_PTR(rc);
 460 }
 461
 462 /**
 463  * xprt_rdma_close - Close down RDMA connection
 464  * @xprt: generic transport to be closed
 465  *
 466  * Called during transport shutdown reconnect, or device
 467  * removal. Caller holds the transport's write lock.
 468  */
 469 static void
 470 xprt_rdma_close(struct rpc_xprt *xprt)
 471 {
 472         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 473         struct rpcrdma_ep *ep = &r_xprt->rx_ep;
 474         struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 475
 476         dprintk("RPC:       %s: closing xprt %p\n", __func__, xprt);
 477
 478         if (test_and_clear_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags)) {
 479                 xprt_clear_connected(xprt);
 480                 rpcrdma_ia_remove(ia);
 481                 return;
 482         }
 483         if (ep->rep_connected == -ENODEV)
 484                 return;
 485         if (ep->rep_connected > 0)
 486                 xprt->reestablish_timeout = 0;
 487         xprt_disconnect_done(xprt);
 488         rpcrdma_ep_disconnect(ep, ia);
 489 }
 490
 491 static void
 492 xprt_rdma_set_port(struct rpc_xprt *xprt, u16 port)
 493 {
 494         struct sockaddr_in *sap;
 495
 496         sap = (struct sockaddr_in *)&xprt->addr;
 497         sap->sin_port = htons(port);
 498         sap = (struct sockaddr_in *)&rpcx_to_rdmad(xprt).addr;
 499         sap->sin_port = htons(port);
 500         dprintk("RPC:       %s: %u\n", __func__, port);
 501 }
 502
 503 /**
 504  * xprt_rdma_timer - invoked when an RPC times out
 505  * @xprt: controlling RPC transport
 506  * @task: RPC task that timed out
 507  *
 508  * Invoked when the transport is still connected, but an RPC
 509  * retransmit timeout occurs.
 510  *
 511  * Since RDMA connections don't have a keep-alive, forcibly
 512  * disconnect and retry to connect. This drives full
 513  * detection of the network path, and retransmissions of
 514  * all pending RPCs.
 515  */
 516 static void
 517 xprt_rdma_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 518 {
 519         dprintk("RPC: %5u %s: xprt = %p\n", task->tk_pid, __func__, xprt);
 520
 521         xprt_force_disconnect(xprt);
 522 }
 523
 524 static void
 525 xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 526 {
 527         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 528
 529         if (r_xprt->rx_ep.rep_connected != 0) {
 530                 /* Reconnect */
 531                 schedule_delayed_work(&r_xprt->rx_connect_worker,
 532                                       xprt->reestablish_timeout);
 533                 xprt->reestablish_timeout <<= 1;
 534                 if (xprt->reestablish_timeout > RPCRDMA_MAX_REEST_TO)
 535                         xprt->reestablish_timeout = RPCRDMA_MAX_REEST_TO;
 536                 else if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
 537                         xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
 538         } else {
 539                 schedule_delayed_work(&r_xprt->rx_connect_worker, 0);
 540                 if (!RPC_IS_ASYNC(task))
 541                         flush_delayed_work(&r_xprt->rx_connect_worker);
 542         }
 543 }
 544
 545 /* Allocate a fixed-size buffer in which to construct and send the
 546  * RPC-over-RDMA header for this request.
 547  */
 548 static bool
 549 rpcrdma_get_rdmabuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 550                     gfp_t flags)
 551 {
 552         size_t size = RPCRDMA_HDRBUF_SIZE;
 553         struct rpcrdma_regbuf *rb;
 554
 555         if (req->rl_rdmabuf)
 556                 return true;
 557
 558         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 559         if (IS_ERR(rb))
 560                 return false;
 561
 562         r_xprt->rx_stats.hardway_register_count += size;
 563         req->rl_rdmabuf = rb;
 564         xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
 565         return true;
 566 }
 567
 568 static bool
 569 rpcrdma_get_sendbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 570                     size_t size, gfp_t flags)
 571 {
 572         struct rpcrdma_regbuf *rb;
 573
 574         if (req->rl_sendbuf && rdmab_length(req->rl_sendbuf) >= size)
 575                 return true;
 576
 577         rb = rpcrdma_alloc_regbuf(size, DMA_TO_DEVICE, flags);
 578         if (IS_ERR(rb))
 579                 return false;
 580
 581         rpcrdma_free_regbuf(req->rl_sendbuf);
 582         r_xprt->rx_stats.hardway_register_count += size;
 583         req->rl_sendbuf = rb;
 584         return true;
 585 }
 586
 587 /* The rq_rcv_buf is used only if a Reply chunk is necessary.
 588  * The decision to use a Reply chunk is made later in
 589  * rpcrdma_marshal_req. This buffer is registered at that time.
 590  *
 591  * Otherwise, the associated RPC Reply arrives in a separate
 592  * Receive buffer, arbitrarily chosen by the HCA. The buffer
 593  * allocated here for the RPC Reply is not utilized in that
 594  * case. See rpcrdma_inline_fixup.
 595  *
 596  * A regbuf is used here to remember the buffer size.
 597  */
 598 static bool
 599 rpcrdma_get_recvbuf(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req,
 600                     size_t size, gfp_t flags)
 601 {
 602         struct rpcrdma_regbuf *rb;
 603
 604         if (req->rl_recvbuf && rdmab_length(req->rl_recvbuf) >= size)
 605                 return true;
 606
 607         rb = rpcrdma_alloc_regbuf(size, DMA_NONE, flags);
 608         if (IS_ERR(rb))
 609                 return false;
 610
 611         rpcrdma_free_regbuf(req->rl_recvbuf);
 612         r_xprt->rx_stats.hardway_register_count += size;
 613         req->rl_recvbuf = rb;
 614         return true;
 615 }
 616
 617 /**
 618  * xprt_rdma_allocate - allocate transport resources for an RPC
 619  * @task: RPC task
 620  *
 621  * Return values:
 622  *        0:    Success; rq_buffer points to RPC buffer to use
 623  *   ENOMEM:    Out of memory, call again later
 624  *      EIO:    A permanent error occurred, do not retry
 625  *
 626  * The RDMA allocate/free functions need the task structure as a place
 627  * to hide the struct rpcrdma_req, which is necessary for the actual
 628  * send/recv sequence.
 629  *
 630  * xprt_rdma_allocate provides buffers that are already mapped for
 631  * DMA, and a local DMA lkey is provided for each.
 632  */
 633 static int
 634 xprt_rdma_allocate(struct rpc_task *task)
 635 {
 636         struct rpc_rqst *rqst = task->tk_rqstp;
 637         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 638         struct rpcrdma_req *req;
 639         gfp_t flags;
 640
 641         req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 642         if (req == NULL)
 643                 return -ENOMEM;
 644
 645         flags = RPCRDMA_DEF_GFP;
 646         if (RPC_IS_SWAPPER(task))
 647                 flags = __GFP_MEMALLOC | GFP_NOWAIT | __GFP_NOWARN;
 648
 649         if (!rpcrdma_get_rdmabuf(r_xprt, req, flags))
 650                 goto out_fail;
 651         if (!rpcrdma_get_sendbuf(r_xprt, req, rqst->rq_callsize, flags))
 652                 goto out_fail;
 653         if (!rpcrdma_get_recvbuf(r_xprt, req, rqst->rq_rcvsize, flags))
 654                 goto out_fail;
 655
 656         dprintk("RPC: %5u %s: send size = %zd, recv size = %zd, req = %p\n",
 657                 task->tk_pid, __func__, rqst->rq_callsize,
 658                 rqst->rq_rcvsize, req);
 659
 660         req->rl_cpu = smp_processor_id();
 661         req->rl_connect_cookie = 0;     /* our reserved value */
 662         rpcrdma_set_xprtdata(rqst, req);
 663         rqst->rq_buffer = req->rl_sendbuf->rg_base;
 664         rqst->rq_rbuffer = req->rl_recvbuf->rg_base;
 665         return 0;
 666
 667 out_fail:
 668         rpcrdma_buffer_put(req);
 669         return -ENOMEM;
 670 }
 671
 672 /**
 673  * xprt_rdma_free - release resources allocated by xprt_rdma_allocate
 674  * @task: RPC task
 675  *
 676  * Caller guarantees rqst->rq_buffer is non-NULL.
 677  */
 678 static void
 679 xprt_rdma_free(struct rpc_task *task)
 680 {
 681         struct rpc_rqst *rqst = task->tk_rqstp;
 682         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(rqst->rq_xprt);
 683         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 684
 685         if (test_bit(RPCRDMA_REQ_F_BACKCHANNEL, &req->rl_flags))
 686                 return;
 687
 688         dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 689
 690         if (test_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags))
 691                 rpcrdma_release_rqst(r_xprt, req);
 692         rpcrdma_buffer_put(req);
 693 }
 694
 695 /**
 696  * xprt_rdma_send_request - marshal and send an RPC request
 697  * @task: RPC task with an RPC message in rq_snd_buf
 698  *
 699  * Caller holds the transport's write lock.
 700  *
 701  * Return values:
 702  *        0:    The request has been sent
 703  * ENOTCONN:    Caller needs to invoke connect logic then call again
 704  *  ENOBUFS:    Call again later to send the request
 705  *      EIO:    A permanent error occurred. The request was not sent,
 706  *              and don't try it again
 707  *
 708  * send_request invokes the meat of RPC RDMA. It must do the following:
 709  *
 710  *  1.  Marshal the RPC request into an RPC RDMA request, which means
 711  *      putting a header in front of data, and creating IOVs for RDMA
 712  *      from those in the request.
 713  *  2.  In marshaling, detect opportunities for RDMA, and use them.
 714  *  3.  Post a recv message to set up asynch completion, then send
 715  *      the request (rpcrdma_ep_post).
 716  *  4.  No partial sends are possible in the RPC-RDMA protocol (as in UDP).
 717  */
 718 static int
 719 xprt_rdma_send_request(struct rpc_task *task)
 720 {
 721         struct rpc_rqst *rqst = task->tk_rqstp;
 722         struct rpc_xprt *xprt = rqst->rq_xprt;
 723         struct rpcrdma_req *req = rpcr_to_rdmar(rqst);
 724         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 725         int rc = 0;
 726
 727         if (!xprt_connected(xprt))
 728                 goto drop_connection;
 729
 730         /* On retransmit, remove any previously registered chunks */
 731         if (unlikely(!list_empty(&req->rl_registered)))
 732                 r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt,
 733                                                     &req->rl_registered);
 734
 735         rc = rpcrdma_marshal_req(r_xprt, rqst);
 736         if (rc < 0)
 737                 goto failed_marshal;
 738
 739         if (req->rl_reply == NULL)              /* e.g. reconnection */
 740                 rpcrdma_recv_buffer_get(req);
 741
 742         /* Must suppress retransmit to maintain credits */
 743         if (req->rl_connect_cookie == xprt->connect_cookie)
 744                 goto drop_connection;
 745         req->rl_connect_cookie = xprt->connect_cookie;
 746
 747         set_bit(RPCRDMA_REQ_F_PENDING, &req->rl_flags);
 748         if (rpcrdma_ep_post(&r_xprt->rx_ia, &r_xprt->rx_ep, req))
 749                 goto drop_connection;
 750
 751         rqst->rq_xmit_bytes_sent += rqst->rq_snd_buf.len;
 752         rqst->rq_bytes_sent = 0;
 753         return 0;
 754
 755 failed_marshal:
 756         if (rc != -ENOTCONN)
 757                 return rc;
 758 drop_connection:
 759         xprt_disconnect_done(xprt);
 760         return -ENOTCONN;       /* implies disconnect */
 761 }
 762
 763 void xprt_rdma_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
 764 {
 765         struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
 766         long idle_time = 0;
 767
 768         if (xprt_connected(xprt))
 769                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
 770
 771         seq_puts(seq, "\txprt:\trdma ");
 772         seq_printf(seq, "%u %lu %lu %lu %ld %lu %lu %lu %llu %llu ",
 773                    0,   /* need a local port? */
 774                    xprt->stat.bind_count,
 775                    xprt->stat.connect_count,
 776                    xprt->stat.connect_time,
 777                    idle_time,
 778                    xprt->stat.sends,
 779                    xprt->stat.recvs,
 780                    xprt->stat.bad_xids,
 781                    xprt->stat.req_u,
 782                    xprt->stat.bklog_u);
 783         seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %lu %lu %lu %lu ",
 784                    r_xprt->rx_stats.read_chunk_count,
 785                    r_xprt->rx_stats.write_chunk_count,
 786                    r_xprt->rx_stats.reply_chunk_count,
 787                    r_xprt->rx_stats.total_rdma_request,
 788                    r_xprt->rx_stats.total_rdma_reply,
 789                    r_xprt->rx_stats.pullup_copy_count,
 790                    r_xprt->rx_stats.fixup_copy_count,
 791                    r_xprt->rx_stats.hardway_register_count,
 792                    r_xprt->rx_stats.failed_marshal_count,
 793                    r_xprt->rx_stats.bad_reply_count,
 794                    r_xprt->rx_stats.nomsg_call_count);
 795         seq_printf(seq, "%lu %lu %lu %lu %lu %lu\n",
 796                    r_xprt->rx_stats.mrs_recovered,
 797                    r_xprt->rx_stats.mrs_orphaned,
 798                    r_xprt->rx_stats.mrs_allocated,
 799                    r_xprt->rx_stats.local_inv_needed,
 800                    r_xprt->rx_stats.empty_sendctx_q,
 801                    r_xprt->rx_stats.reply_waits_for_send);
 802 }
 803
 804 static int
 805 xprt_rdma_enable_swap(struct rpc_xprt *xprt)
 806 {
 807         return 0;
 808 }
 809
 810 static void
 811 xprt_rdma_disable_swap(struct rpc_xprt *xprt)
 812 {
 813 }
 814
 815 /*
 816  * Plumbing for rpc transport switch and kernel module
 817  */
 818
 819 static const struct rpc_xprt_ops xprt_rdma_procs = {
 820         .reserve_xprt           = xprt_reserve_xprt_cong,
 821         .release_xprt           = xprt_release_xprt_cong, /* sunrpc/xprt.c */
 822         .alloc_slot             = xprt_alloc_slot,
 823         .release_request        = xprt_release_rqst_cong,       /* ditto */
 824         .set_retrans_timeout    = xprt_set_retrans_timeout_def, /* ditto */
 825         .timer                  = xprt_rdma_timer,
 826         .rpcbind                = rpcb_getport_async,   /* sunrpc/rpcb_clnt.c */
 827         .set_port               = xprt_rdma_set_port,
 828         .connect                = xprt_rdma_connect,
 829         .buf_alloc              = xprt_rdma_allocate,
 830         .buf_free               = xprt_rdma_free,
 831         .send_request           = xprt_rdma_send_request,
 832         .close                  = xprt_rdma_close,
 833         .destroy                = xprt_rdma_destroy,
 834         .print_stats            = xprt_rdma_print_stats,
 835         .enable_swap            = xprt_rdma_enable_swap,
 836         .disable_swap           = xprt_rdma_disable_swap,
 837         .inject_disconnect      = xprt_rdma_inject_disconnect,
 838 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 839         .bc_setup               = xprt_rdma_bc_setup,
 840         .bc_up                  = xprt_rdma_bc_up,
 841         .bc_maxpayload          = xprt_rdma_bc_maxpayload,
 842         .bc_free_rqst           = xprt_rdma_bc_free_rqst,
 843         .bc_destroy             = xprt_rdma_bc_destroy,
 844 #endif
 845 };
 846
 847 static struct xprt_class xprt_rdma = {
 848         .list                   = LIST_HEAD_INIT(xprt_rdma.list),
 849         .name                   = "rdma",
 850         .owner                  = THIS_MODULE,
 851         .ident                  = XPRT_TRANSPORT_RDMA,
 852         .setup                  = xprt_setup_rdma,
 853 };
 854
 855 void xprt_rdma_cleanup(void)
 856 {
 857         int rc;
 858
 859         dprintk("RPCRDMA Module Removed, deregister RPC RDMA transport\n");
 860 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 861         if (sunrpc_table_header) {
 862                 unregister_sysctl_table(sunrpc_table_header);
 863                 sunrpc_table_header = NULL;
 864         }
 865 #endif
 866         rc = xprt_unregister_transport(&xprt_rdma);
 867         if (rc)
 868                 dprintk("RPC:       %s: xprt_unregister returned %i\n",
 869                         __func__, rc);
 870
 871         rpcrdma_destroy_wq();
 872
 873         rc = xprt_unregister_transport(&xprt_rdma_bc);
 874         if (rc)
 875                 dprintk("RPC:       %s: xprt_unregister(bc) returned %i\n",
 876                         __func__, rc);
 877 }
 878
 879 int xprt_rdma_init(void)
 880 {
 881         int rc;
 882
 883         rc = rpcrdma_alloc_wq();
 884         if (rc)
 885                 return rc;
 886
 887         rc = xprt_register_transport(&xprt_rdma);
 888         if (rc) {
 889                 rpcrdma_destroy_wq();
 890                 return rc;
 891         }
 892
 893         rc = xprt_register_transport(&xprt_rdma_bc);
 894         if (rc) {
 895                 xprt_unregister_transport(&xprt_rdma);
 896                 rpcrdma_destroy_wq();
 897                 return rc;
 898         }
 899
 900         dprintk("RPCRDMA Module Init, register RPC RDMA transport\n");
 901
 902         dprintk("Defaults:\n");
 903         dprintk("\tSlots %d\n"
 904                 "\tMaxInlineRead %d\n\tMaxInlineWrite %d\n",
 905                 xprt_rdma_slot_table_entries,
 906                 xprt_rdma_max_inline_read, xprt_rdma_max_inline_write);
 907         dprintk("\tPadding %d\n\tMemreg %d\n",
 908                 xprt_rdma_inline_write_padding, xprt_rdma_memreg_strategy);
 909
 910 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 911         if (!sunrpc_table_header)
 912                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
 913 #endif
 914         return 0;
 915 }