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