net/rds/ib_cm.c

   1 /*
   2  * Copyright (c) 2006 Oracle.  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
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        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
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  */
  33 #include <linux/kernel.h>
  34 #include <linux/in.h>
  35 #include <linux/slab.h>
  36 #include <linux/vmalloc.h>
  37 #include <linux/ratelimit.h>
  38
  39 #include "rds.h"
  40 #include "ib.h"
  41
  42 /*
  43  * Set the selected protocol version
  44  */
  45 static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
  46 {
  47         conn->c_version = version;
  48 }
  49
  50 /*
  51  * Set up flow control
  52  */
  53 static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
  54 {
  55         struct rds_ib_connection *ic = conn->c_transport_data;
  56
  57         if (rds_ib_sysctl_flow_control && credits != 0) {
  58                 /* We're doing flow control */
  59                 ic->i_flowctl = 1;
  60                 rds_ib_send_add_credits(conn, credits);
  61         } else {
  62                 ic->i_flowctl = 0;
  63         }
  64 }
  65
  66 /*
  67  * Tune RNR behavior. Without flow control, we use a rather
  68  * low timeout, but not the absolute minimum - this should
  69  * be tunable.
  70  *
  71  * We already set the RNR retry count to 7 (which is the
  72  * smallest infinite number :-) above.
  73  * If flow control is off, we want to change this back to 0
  74  * so that we learn quickly when our credit accounting is
  75  * buggy.
  76  *
  77  * Caller passes in a qp_attr pointer - don't waste stack spacv
  78  * by allocation this twice.
  79  */
  80 static void
  81 rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
  82 {
  83         int ret;
  84
  85         attr->min_rnr_timer = IB_RNR_TIMER_000_32;
  86         ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
  87         if (ret)
  88                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
  89 }
  90
  91 /*
  92  * Connection established.
  93  * We get here for both outgoing and incoming connection.
  94  */
  95 void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
  96 {
  97         const struct rds_ib_connect_private *dp = NULL;
  98         struct rds_ib_connection *ic = conn->c_transport_data;
  99         struct ib_qp_attr qp_attr;
 100         int err;
 101
 102         if (event->param.conn.private_data_len >= sizeof(*dp)) {
 103                 dp = event->param.conn.private_data;
 104
 105                 /* make sure it isn't empty data */
 106                 if (dp->dp_protocol_major) {
 107                         rds_ib_set_protocol(conn,
 108                                 RDS_PROTOCOL(dp->dp_protocol_major,
 109                                 dp->dp_protocol_minor));
 110                         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 111                 }
 112         }
 113
 114         if (conn->c_version < RDS_PROTOCOL(3,1)) {
 115                 printk(KERN_NOTICE "RDS/IB: Connection to %pI4 version %u.%u failed,"
 116                        " no longer supported\n",
 117                        &conn->c_faddr,
 118                        RDS_PROTOCOL_MAJOR(conn->c_version),
 119                        RDS_PROTOCOL_MINOR(conn->c_version));
 120                 rds_conn_destroy(conn);
 121                 return;
 122         } else {
 123                 printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
 124                        &conn->c_faddr,
 125                        RDS_PROTOCOL_MAJOR(conn->c_version),
 126                        RDS_PROTOCOL_MINOR(conn->c_version),
 127                        ic->i_flowctl ? ", flow control" : "");
 128         }
 129
 130         /*
 131          * Init rings and fill recv. this needs to wait until protocol negotiation
 132          * is complete, since ring layout is different from 3.0 to 3.1.
 133          */
 134         rds_ib_send_init_ring(ic);
 135         rds_ib_recv_init_ring(ic);
 136         /* Post receive buffers - as a side effect, this will update
 137          * the posted credit count. */
 138         rds_ib_recv_refill(conn, 1, GFP_KERNEL);
 139
 140         /* Tune RNR behavior */
 141         rds_ib_tune_rnr(ic, &qp_attr);
 142
 143         qp_attr.qp_state = IB_QPS_RTS;
 144         err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
 145         if (err)
 146                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
 147
 148         /* update ib_device with this local ipaddr */
 149         err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr);
 150         if (err)
 151                 printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n",
 152                         err);
 153
 154         /* If the peer gave us the last packet it saw, process this as if
 155          * we had received a regular ACK. */
 156         if (dp) {
 157                 /* dp structure start is not guaranteed to be 8 bytes aligned.
 158                  * Since dp_ack_seq is 64-bit extended load operations can be
 159                  * used so go through get_unaligned to avoid unaligned errors.
 160                  */
 161                 __be64 dp_ack_seq = get_unaligned(&dp->dp_ack_seq);
 162
 163                 if (dp_ack_seq)
 164                         rds_send_drop_acked(conn, be64_to_cpu(dp_ack_seq),
 165                                             NULL);
 166         }
 167
 168         rds_connect_complete(conn);
 169 }
 170
 171 static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
 172                         struct rdma_conn_param *conn_param,
 173                         struct rds_ib_connect_private *dp,
 174                         u32 protocol_version,
 175                         u32 max_responder_resources,
 176                         u32 max_initiator_depth)
 177 {
 178         struct rds_ib_connection *ic = conn->c_transport_data;
 179         struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 180
 181         memset(conn_param, 0, sizeof(struct rdma_conn_param));
 182
 183         conn_param->responder_resources =
 184                 min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
 185         conn_param->initiator_depth =
 186                 min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
 187         conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
 188         conn_param->rnr_retry_count = 7;
 189
 190         if (dp) {
 191                 memset(dp, 0, sizeof(*dp));
 192                 dp->dp_saddr = conn->c_laddr;
 193                 dp->dp_daddr = conn->c_faddr;
 194                 dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
 195                 dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
 196                 dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
 197                 dp->dp_ack_seq = rds_ib_piggyb_ack(ic);
 198
 199                 /* Advertise flow control */
 200                 if (ic->i_flowctl) {
 201                         unsigned int credits;
 202
 203                         credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
 204                         dp->dp_credit = cpu_to_be32(credits);
 205                         atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
 206                 }
 207
 208                 conn_param->private_data = dp;
 209                 conn_param->private_data_len = sizeof(*dp);
 210         }
 211 }
 212
 213 static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
 214 {
 215         rdsdebug("event %u (%s) data %p\n",
 216                  event->event, ib_event_msg(event->event), data);
 217 }
 218
 219 /* Plucking the oldest entry from the ring can be done concurrently with
 220  * the thread refilling the ring.  Each ring operation is protected by
 221  * spinlocks and the transient state of refilling doesn't change the
 222  * recording of which entry is oldest.
 223  *
 224  * This relies on IB only calling one cq comp_handler for each cq so that
 225  * there will only be one caller of rds_recv_incoming() per RDS connection.
 226  */
 227 static void rds_ib_cq_comp_handler_recv(struct ib_cq *cq, void *context)
 228 {
 229         struct rds_connection *conn = context;
 230         struct rds_ib_connection *ic = conn->c_transport_data;
 231
 232         rdsdebug("conn %p cq %p\n", conn, cq);
 233
 234         rds_ib_stats_inc(s_ib_evt_handler_call);
 235
 236         tasklet_schedule(&ic->i_recv_tasklet);
 237 }
 238
 239 static void poll_cq(struct rds_ib_connection *ic, struct ib_cq *cq,
 240                     struct ib_wc *wcs,
 241                     struct rds_ib_ack_state *ack_state)
 242 {
 243         int nr;
 244         int i;
 245         struct ib_wc *wc;
 246
 247         while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
 248                 for (i = 0; i < nr; i++) {
 249                         wc = wcs + i;
 250                         rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
 251                                  (unsigned long long)wc->wr_id, wc->status,
 252                                  wc->byte_len, be32_to_cpu(wc->ex.imm_data));
 253
 254                         if (wc->wr_id & RDS_IB_SEND_OP)
 255                                 rds_ib_send_cqe_handler(ic, wc);
 256                         else
 257                                 rds_ib_recv_cqe_handler(ic, wc, ack_state);
 258                 }
 259         }
 260 }
 261
 262 static void rds_ib_tasklet_fn_send(unsigned long data)
 263 {
 264         struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
 265         struct rds_connection *conn = ic->conn;
 266         struct rds_ib_ack_state state;
 267
 268         rds_ib_stats_inc(s_ib_tasklet_call);
 269
 270         memset(&state, 0, sizeof(state));
 271         poll_cq(ic, ic->i_send_cq, ic->i_send_wc, &state);
 272         ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 273         poll_cq(ic, ic->i_send_cq, ic->i_send_wc, &state);
 274
 275         if (rds_conn_up(conn) &&
 276             (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
 277             test_bit(0, &conn->c_map_queued)))
 278                 rds_send_xmit(ic->conn);
 279 }
 280
 281 static void rds_ib_tasklet_fn_recv(unsigned long data)
 282 {
 283         struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
 284         struct rds_connection *conn = ic->conn;
 285         struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
 286         struct rds_ib_ack_state state;
 287
 288         if (!rds_ibdev)
 289                 rds_conn_drop(conn);
 290
 291         rds_ib_stats_inc(s_ib_tasklet_call);
 292
 293         memset(&state, 0, sizeof(state));
 294         poll_cq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
 295         ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 296         poll_cq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
 297
 298         if (state.ack_next_valid)
 299                 rds_ib_set_ack(ic, state.ack_next, state.ack_required);
 300         if (state.ack_recv_valid && state.ack_recv > ic->i_ack_recv) {
 301                 rds_send_drop_acked(conn, state.ack_recv, NULL);
 302                 ic->i_ack_recv = state.ack_recv;
 303         }
 304
 305         if (rds_conn_up(conn))
 306                 rds_ib_attempt_ack(ic);
 307 }
 308
 309 static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
 310 {
 311         struct rds_connection *conn = data;
 312         struct rds_ib_connection *ic = conn->c_transport_data;
 313
 314         rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
 315                  ib_event_msg(event->event));
 316
 317         switch (event->event) {
 318         case IB_EVENT_COMM_EST:
 319                 rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
 320                 break;
 321         default:
 322                 rdsdebug("Fatal QP Event %u (%s) "
 323                         "- connection %pI4->%pI4, reconnecting\n",
 324                         event->event, ib_event_msg(event->event),
 325                         &conn->c_laddr, &conn->c_faddr);
 326                 rds_conn_drop(conn);
 327                 break;
 328         }
 329 }
 330
 331 static void rds_ib_cq_comp_handler_send(struct ib_cq *cq, void *context)
 332 {
 333         struct rds_connection *conn = context;
 334         struct rds_ib_connection *ic = conn->c_transport_data;
 335
 336         rdsdebug("conn %p cq %p\n", conn, cq);
 337
 338         rds_ib_stats_inc(s_ib_evt_handler_call);
 339
 340         tasklet_schedule(&ic->i_send_tasklet);
 341 }
 342
 343 /*
 344  * This needs to be very careful to not leave IS_ERR pointers around for
 345  * cleanup to trip over.
 346  */
 347 static int rds_ib_setup_qp(struct rds_connection *conn)
 348 {
 349         struct rds_ib_connection *ic = conn->c_transport_data;
 350         struct ib_device *dev = ic->i_cm_id->device;
 351         struct ib_qp_init_attr attr;
 352         struct ib_cq_init_attr cq_attr = {};
 353         struct rds_ib_device *rds_ibdev;
 354         int ret;
 355
 356         /*
 357          * It's normal to see a null device if an incoming connection races
 358          * with device removal, so we don't print a warning.
 359          */
 360         rds_ibdev = rds_ib_get_client_data(dev);
 361         if (!rds_ibdev)
 362                 return -EOPNOTSUPP;
 363
 364         /* add the conn now so that connection establishment has the dev */
 365         rds_ib_add_conn(rds_ibdev, conn);
 366
 367         if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
 368                 rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
 369         if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
 370                 rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
 371
 372         /* Protection domain and memory range */
 373         ic->i_pd = rds_ibdev->pd;
 374
 375         cq_attr.cqe = ic->i_send_ring.w_nr + 1;
 376
 377         ic->i_send_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_send,
 378                                      rds_ib_cq_event_handler, conn,
 379                                      &cq_attr);
 380         if (IS_ERR(ic->i_send_cq)) {
 381                 ret = PTR_ERR(ic->i_send_cq);
 382                 ic->i_send_cq = NULL;
 383                 rdsdebug("ib_create_cq send failed: %d\n", ret);
 384                 goto out;
 385         }
 386
 387         cq_attr.cqe = ic->i_recv_ring.w_nr;
 388         ic->i_recv_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_recv,
 389                                      rds_ib_cq_event_handler, conn,
 390                                      &cq_attr);
 391         if (IS_ERR(ic->i_recv_cq)) {
 392                 ret = PTR_ERR(ic->i_recv_cq);
 393                 ic->i_recv_cq = NULL;
 394                 rdsdebug("ib_create_cq recv failed: %d\n", ret);
 395                 goto out;
 396         }
 397
 398         ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 399         if (ret) {
 400                 rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
 401                 goto out;
 402         }
 403
 404         ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 405         if (ret) {
 406                 rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
 407                 goto out;
 408         }
 409
 410         /* XXX negotiate max send/recv with remote? */
 411         memset(&attr, 0, sizeof(attr));
 412         attr.event_handler = rds_ib_qp_event_handler;
 413         attr.qp_context = conn;
 414         /* + 1 to allow for the single ack message */
 415         attr.cap.max_send_wr = ic->i_send_ring.w_nr + 1;
 416         attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
 417         attr.cap.max_send_sge = rds_ibdev->max_sge;
 418         attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
 419         attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 420         attr.qp_type = IB_QPT_RC;
 421         attr.send_cq = ic->i_send_cq;
 422         attr.recv_cq = ic->i_recv_cq;
 423
 424         /*
 425          * XXX this can fail if max_*_wr is too large?  Are we supposed
 426          * to back off until we get a value that the hardware can support?
 427          */
 428         ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
 429         if (ret) {
 430                 rdsdebug("rdma_create_qp failed: %d\n", ret);
 431                 goto out;
 432         }
 433
 434         ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
 435                                            ic->i_send_ring.w_nr *
 436                                                 sizeof(struct rds_header),
 437                                            &ic->i_send_hdrs_dma, GFP_KERNEL);
 438         if (!ic->i_send_hdrs) {
 439                 ret = -ENOMEM;
 440                 rdsdebug("ib_dma_alloc_coherent send failed\n");
 441                 goto out;
 442         }
 443
 444         ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
 445                                            ic->i_recv_ring.w_nr *
 446                                                 sizeof(struct rds_header),
 447                                            &ic->i_recv_hdrs_dma, GFP_KERNEL);
 448         if (!ic->i_recv_hdrs) {
 449                 ret = -ENOMEM;
 450                 rdsdebug("ib_dma_alloc_coherent recv failed\n");
 451                 goto out;
 452         }
 453
 454         ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
 455                                        &ic->i_ack_dma, GFP_KERNEL);
 456         if (!ic->i_ack) {
 457                 ret = -ENOMEM;
 458                 rdsdebug("ib_dma_alloc_coherent ack failed\n");
 459                 goto out;
 460         }
 461
 462         ic->i_sends = vzalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
 463                                    ibdev_to_node(dev));
 464         if (!ic->i_sends) {
 465                 ret = -ENOMEM;
 466                 rdsdebug("send allocation failed\n");
 467                 goto out;
 468         }
 469
 470         ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
 471                                    ibdev_to_node(dev));
 472         if (!ic->i_recvs) {
 473                 ret = -ENOMEM;
 474                 rdsdebug("recv allocation failed\n");
 475                 goto out;
 476         }
 477
 478         rds_ib_recv_init_ack(ic);
 479
 480         rdsdebug("conn %p pd %p cq %p %p\n", conn, ic->i_pd,
 481                  ic->i_send_cq, ic->i_recv_cq);
 482
 483 out:
 484         rds_ib_dev_put(rds_ibdev);
 485         return ret;
 486 }
 487
 488 static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
 489 {
 490         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 491         u16 common;
 492         u32 version = 0;
 493
 494         /*
 495          * rdma_cm private data is odd - when there is any private data in the
 496          * request, we will be given a pretty large buffer without telling us the
 497          * original size. The only way to tell the difference is by looking at
 498          * the contents, which are initialized to zero.
 499          * If the protocol version fields aren't set, this is a connection attempt
 500          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
 501          * We really should have changed this for OFED 1.3 :-(
 502          */
 503
 504         /* Be paranoid. RDS always has privdata */
 505         if (!event->param.conn.private_data_len) {
 506                 printk(KERN_NOTICE "RDS incoming connection has no private data, "
 507                         "rejecting\n");
 508                 return 0;
 509         }
 510
 511         /* Even if len is crap *now* I still want to check it. -ASG */
 512         if (event->param.conn.private_data_len < sizeof (*dp) ||
 513             dp->dp_protocol_major == 0)
 514                 return RDS_PROTOCOL_3_0;
 515
 516         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
 517         if (dp->dp_protocol_major == 3 && common) {
 518                 version = RDS_PROTOCOL_3_0;
 519                 while ((common >>= 1) != 0)
 520                         version++;
 521         } else
 522                 printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using incompatible protocol version %u.%u\n",
 523                                 &dp->dp_saddr,
 524                                 dp->dp_protocol_major,
 525                                 dp->dp_protocol_minor);
 526         return version;
 527 }
 528
 529 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 530                                     struct rdma_cm_event *event)
 531 {
 532         __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
 533         __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
 534         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 535         struct rds_ib_connect_private dp_rep;
 536         struct rds_connection *conn = NULL;
 537         struct rds_ib_connection *ic = NULL;
 538         struct rdma_conn_param conn_param;
 539         u32 version;
 540         int err = 1, destroy = 1;
 541
 542         /* Check whether the remote protocol version matches ours. */
 543         version = rds_ib_protocol_compatible(event);
 544         if (!version)
 545                 goto out;
 546
 547         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
 548                  "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
 549                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
 550                  (unsigned long long)be64_to_cpu(lguid),
 551                  (unsigned long long)be64_to_cpu(fguid));
 552
 553         /* RDS/IB is not currently netns aware, thus init_net */
 554         conn = rds_conn_create(&init_net, dp->dp_daddr, dp->dp_saddr,
 555                                &rds_ib_transport, GFP_KERNEL);
 556         if (IS_ERR(conn)) {
 557                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 558                 conn = NULL;
 559                 goto out;
 560         }
 561
 562         /*
 563          * The connection request may occur while the
 564          * previous connection exist, e.g. in case of failover.
 565          * But as connections may be initiated simultaneously
 566          * by both hosts, we have a random backoff mechanism -
 567          * see the comment above rds_queue_reconnect()
 568          */
 569         mutex_lock(&conn->c_cm_lock);
 570         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 571                 if (rds_conn_state(conn) == RDS_CONN_UP) {
 572                         rdsdebug("incoming connect while connecting\n");
 573                         rds_conn_drop(conn);
 574                         rds_ib_stats_inc(s_ib_listen_closed_stale);
 575                 } else
 576                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
 577                         /* Wait and see - our connect may still be succeeding */
 578                         rds_ib_stats_inc(s_ib_connect_raced);
 579                 }
 580                 goto out;
 581         }
 582
 583         ic = conn->c_transport_data;
 584
 585         rds_ib_set_protocol(conn, version);
 586         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 587
 588         /* If the peer gave us the last packet it saw, process this as if
 589          * we had received a regular ACK. */
 590         if (dp->dp_ack_seq)
 591                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 592
 593         BUG_ON(cm_id->context);
 594         BUG_ON(ic->i_cm_id);
 595
 596         ic->i_cm_id = cm_id;
 597         cm_id->context = conn;
 598
 599         /* We got halfway through setting up the ib_connection, if we
 600          * fail now, we have to take the long route out of this mess. */
 601         destroy = 0;
 602
 603         err = rds_ib_setup_qp(conn);
 604         if (err) {
 605                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
 606                 goto out;
 607         }
 608
 609         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
 610                 event->param.conn.responder_resources,
 611                 event->param.conn.initiator_depth);
 612
 613         /* rdma_accept() calls rdma_reject() internally if it fails */
 614         err = rdma_accept(cm_id, &conn_param);
 615         if (err)
 616                 rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
 617
 618 out:
 619         if (conn)
 620                 mutex_unlock(&conn->c_cm_lock);
 621         if (err)
 622                 rdma_reject(cm_id, NULL, 0);
 623         return destroy;
 624 }
 625
 626
 627 int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
 628 {
 629         struct rds_connection *conn = cm_id->context;
 630         struct rds_ib_connection *ic = conn->c_transport_data;
 631         struct rdma_conn_param conn_param;
 632         struct rds_ib_connect_private dp;
 633         int ret;
 634
 635         /* If the peer doesn't do protocol negotiation, we must
 636          * default to RDSv3.0 */
 637         rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
 638         ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
 639
 640         ret = rds_ib_setup_qp(conn);
 641         if (ret) {
 642                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
 643                 goto out;
 644         }
 645
 646         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
 647                 UINT_MAX, UINT_MAX);
 648         ret = rdma_connect(cm_id, &conn_param);
 649         if (ret)
 650                 rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
 651
 652 out:
 653         /* Beware - returning non-zero tells the rdma_cm to destroy
 654          * the cm_id. We should certainly not do it as long as we still
 655          * "own" the cm_id. */
 656         if (ret) {
 657                 if (ic->i_cm_id == cm_id)
 658                         ret = 0;
 659         }
 660         return ret;
 661 }
 662
 663 int rds_ib_conn_connect(struct rds_connection *conn)
 664 {
 665         struct rds_ib_connection *ic = conn->c_transport_data;
 666         struct sockaddr_in src, dest;
 667         int ret;
 668
 669         /* XXX I wonder what affect the port space has */
 670         /* delegate cm event handler to rdma_transport */
 671         ic->i_cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, conn,
 672                                      RDMA_PS_TCP, IB_QPT_RC);
 673         if (IS_ERR(ic->i_cm_id)) {
 674                 ret = PTR_ERR(ic->i_cm_id);
 675                 ic->i_cm_id = NULL;
 676                 rdsdebug("rdma_create_id() failed: %d\n", ret);
 677                 goto out;
 678         }
 679
 680         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
 681
 682         src.sin_family = AF_INET;
 683         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
 684         src.sin_port = (__force u16)htons(0);
 685
 686         dest.sin_family = AF_INET;
 687         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 688         dest.sin_port = (__force u16)htons(RDS_PORT);
 689
 690         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
 691                                 (struct sockaddr *)&dest,
 692                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
 693         if (ret) {
 694                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
 695                          ret);
 696                 rdma_destroy_id(ic->i_cm_id);
 697                 ic->i_cm_id = NULL;
 698         }
 699
 700 out:
 701         return ret;
 702 }
 703
 704 /*
 705  * This is so careful about only cleaning up resources that were built up
 706  * so that it can be called at any point during startup.  In fact it
 707  * can be called multiple times for a given connection.
 708  */
 709 void rds_ib_conn_shutdown(struct rds_connection *conn)
 710 {
 711         struct rds_ib_connection *ic = conn->c_transport_data;
 712         int err = 0;
 713
 714         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
 715                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
 716                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
 717
 718         if (ic->i_cm_id) {
 719                 struct ib_device *dev = ic->i_cm_id->device;
 720
 721                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
 722                 err = rdma_disconnect(ic->i_cm_id);
 723                 if (err) {
 724                         /* Actually this may happen quite frequently, when
 725                          * an outgoing connect raced with an incoming connect.
 726                          */
 727                         rdsdebug("failed to disconnect, cm: %p err %d\n",
 728                                 ic->i_cm_id, err);
 729                 }
 730
 731                 /*
 732                  * We want to wait for tx and rx completion to finish
 733                  * before we tear down the connection, but we have to be
 734                  * careful not to get stuck waiting on a send ring that
 735                  * only has unsignaled sends in it.  We've shutdown new
 736                  * sends before getting here so by waiting for signaled
 737                  * sends to complete we're ensured that there will be no
 738                  * more tx processing.
 739                  */
 740                 wait_event(rds_ib_ring_empty_wait,
 741                            rds_ib_ring_empty(&ic->i_recv_ring) &&
 742                            (atomic_read(&ic->i_signaled_sends) == 0));
 743                 tasklet_kill(&ic->i_send_tasklet);
 744                 tasklet_kill(&ic->i_recv_tasklet);
 745
 746                 /* first destroy the ib state that generates callbacks */
 747                 if (ic->i_cm_id->qp)
 748                         rdma_destroy_qp(ic->i_cm_id);
 749                 if (ic->i_send_cq)
 750                         ib_destroy_cq(ic->i_send_cq);
 751                 if (ic->i_recv_cq)
 752                         ib_destroy_cq(ic->i_recv_cq);
 753
 754                 /* then free the resources that ib callbacks use */
 755                 if (ic->i_send_hdrs)
 756                         ib_dma_free_coherent(dev,
 757                                            ic->i_send_ring.w_nr *
 758                                                 sizeof(struct rds_header),
 759                                            ic->i_send_hdrs,
 760                                            ic->i_send_hdrs_dma);
 761
 762                 if (ic->i_recv_hdrs)
 763                         ib_dma_free_coherent(dev,
 764                                            ic->i_recv_ring.w_nr *
 765                                                 sizeof(struct rds_header),
 766                                            ic->i_recv_hdrs,
 767                                            ic->i_recv_hdrs_dma);
 768
 769                 if (ic->i_ack)
 770                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
 771                                              ic->i_ack, ic->i_ack_dma);
 772
 773                 if (ic->i_sends)
 774                         rds_ib_send_clear_ring(ic);
 775                 if (ic->i_recvs)
 776                         rds_ib_recv_clear_ring(ic);
 777
 778                 rdma_destroy_id(ic->i_cm_id);
 779
 780                 /*
 781                  * Move connection back to the nodev list.
 782                  */
 783                 if (ic->rds_ibdev)
 784                         rds_ib_remove_conn(ic->rds_ibdev, conn);
 785
 786                 ic->i_cm_id = NULL;
 787                 ic->i_pd = NULL;
 788                 ic->i_send_cq = NULL;
 789                 ic->i_recv_cq = NULL;
 790                 ic->i_send_hdrs = NULL;
 791                 ic->i_recv_hdrs = NULL;
 792                 ic->i_ack = NULL;
 793         }
 794         BUG_ON(ic->rds_ibdev);
 795
 796         /* Clear pending transmit */
 797         if (ic->i_data_op) {
 798                 struct rds_message *rm;
 799
 800                 rm = container_of(ic->i_data_op, struct rds_message, data);
 801                 rds_message_put(rm);
 802                 ic->i_data_op = NULL;
 803         }
 804
 805         /* Clear the ACK state */
 806         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
 807 #ifdef KERNEL_HAS_ATOMIC64
 808         atomic64_set(&ic->i_ack_next, 0);
 809 #else
 810         ic->i_ack_next = 0;
 811 #endif
 812         ic->i_ack_recv = 0;
 813
 814         /* Clear flow control state */
 815         ic->i_flowctl = 0;
 816         atomic_set(&ic->i_credits, 0);
 817
 818         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 819         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 820
 821         if (ic->i_ibinc) {
 822                 rds_inc_put(&ic->i_ibinc->ii_inc);
 823                 ic->i_ibinc = NULL;
 824         }
 825
 826         vfree(ic->i_sends);
 827         ic->i_sends = NULL;
 828         vfree(ic->i_recvs);
 829         ic->i_recvs = NULL;
 830 }
 831
 832 int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 833 {
 834         struct rds_ib_connection *ic;
 835         unsigned long flags;
 836         int ret;
 837
 838         /* XXX too lazy? */
 839         ic = kzalloc(sizeof(struct rds_ib_connection), gfp);
 840         if (!ic)
 841                 return -ENOMEM;
 842
 843         ret = rds_ib_recv_alloc_caches(ic);
 844         if (ret) {
 845                 kfree(ic);
 846                 return ret;
 847         }
 848
 849         INIT_LIST_HEAD(&ic->ib_node);
 850         tasklet_init(&ic->i_send_tasklet, rds_ib_tasklet_fn_send,
 851                      (unsigned long)ic);
 852         tasklet_init(&ic->i_recv_tasklet, rds_ib_tasklet_fn_recv,
 853                      (unsigned long)ic);
 854         mutex_init(&ic->i_recv_mutex);
 855 #ifndef KERNEL_HAS_ATOMIC64
 856         spin_lock_init(&ic->i_ack_lock);
 857 #endif
 858         atomic_set(&ic->i_signaled_sends, 0);
 859
 860         /*
 861          * rds_ib_conn_shutdown() waits for these to be emptied so they
 862          * must be initialized before it can be called.
 863          */
 864         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 865         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 866
 867         ic->conn = conn;
 868         conn->c_transport_data = ic;
 869
 870         spin_lock_irqsave(&ib_nodev_conns_lock, flags);
 871         list_add_tail(&ic->ib_node, &ib_nodev_conns);
 872         spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
 873
 874
 875         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
 876         return 0;
 877 }
 878
 879 /*
 880  * Free a connection. Connection must be shut down and not set for reconnect.
 881  */
 882 void rds_ib_conn_free(void *arg)
 883 {
 884         struct rds_ib_connection *ic = arg;
 885         spinlock_t      *lock_ptr;
 886
 887         rdsdebug("ic %p\n", ic);
 888
 889         /*
 890          * Conn is either on a dev's list or on the nodev list.
 891          * A race with shutdown() or connect() would cause problems
 892          * (since rds_ibdev would change) but that should never happen.
 893          */
 894         lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
 895
 896         spin_lock_irq(lock_ptr);
 897         list_del(&ic->ib_node);
 898         spin_unlock_irq(lock_ptr);
 899
 900         rds_ib_recv_free_caches(ic);
 901
 902         kfree(ic);
 903 }
 904
 905
 906 /*
 907  * An error occurred on the connection
 908  */
 909 void
 910 __rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
 911 {
 912         va_list ap;
 913
 914         rds_conn_drop(conn);
 915
 916         va_start(ap, fmt);
 917         vprintk(fmt, ap);
 918         va_end(ap);
 919 }