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