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   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/vmalloc.h>
  36
  37 #include "rds.h"
  38 #include "ib.h"
  39
  40 /*
  41  * Set the selected protocol version
  42  */
  43 static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
  44 {
  45         conn->c_version = version;
  46 }
  47
  48 /*
  49  * Set up flow control
  50  */
  51 static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
  52 {
  53         struct rds_ib_connection *ic = conn->c_transport_data;
  54
  55         if (rds_ib_sysctl_flow_control && credits != 0) {
  56                 /* We're doing flow control */
  57                 ic->i_flowctl = 1;
  58                 rds_ib_send_add_credits(conn, credits);
  59         } else {
  60                 ic->i_flowctl = 0;
  61         }
  62 }
  63
  64 /*
  65  * Tune RNR behavior. Without flow control, we use a rather
  66  * low timeout, but not the absolute minimum - this should
  67  * be tunable.
  68  *
  69  * We already set the RNR retry count to 7 (which is the
  70  * smallest infinite number :-) above.
  71  * If flow control is off, we want to change this back to 0
  72  * so that we learn quickly when our credit accounting is
  73  * buggy.
  74  *
  75  * Caller passes in a qp_attr pointer - don't waste stack spacv
  76  * by allocation this twice.
  77  */
  78 static void
  79 rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
  80 {
  81         int ret;
  82
  83         attr->min_rnr_timer = IB_RNR_TIMER_000_32;
  84         ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
  85         if (ret)
  86                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
  87 }
  88
  89 /*
  90  * Connection established.
  91  * We get here for both outgoing and incoming connection.
  92  */
  93 void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
  94 {
  95         const struct rds_ib_connect_private *dp = NULL;
  96         struct rds_ib_connection *ic = conn->c_transport_data;
  97         struct rds_ib_device *rds_ibdev;
  98         struct ib_qp_attr qp_attr;
  99         int err;
 100
 101         if (event->param.conn.private_data_len) {
 102                 dp = event->param.conn.private_data;
 103
 104                 rds_ib_set_protocol(conn,
 105                                 RDS_PROTOCOL(dp->dp_protocol_major,
 106                                         dp->dp_protocol_minor));
 107                 rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 108         }
 109
 110         printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
 111                         &conn->c_laddr,
 112                         RDS_PROTOCOL_MAJOR(conn->c_version),
 113                         RDS_PROTOCOL_MINOR(conn->c_version),
 114                         ic->i_flowctl ? ", flow control" : "");
 115
 116         /* Tune RNR behavior */
 117         rds_ib_tune_rnr(ic, &qp_attr);
 118
 119         qp_attr.qp_state = IB_QPS_RTS;
 120         err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
 121         if (err)
 122                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
 123
 124         /* update ib_device with this local ipaddr & conn */
 125         rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client);
 126         err = rds_ib_update_ipaddr(rds_ibdev, conn->c_laddr);
 127         if (err)
 128                 printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n", err);
 129         rds_ib_add_conn(rds_ibdev, conn);
 130
 131         /* If the peer gave us the last packet it saw, process this as if
 132          * we had received a regular ACK. */
 133         if (dp && dp->dp_ack_seq)
 134                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 135
 136         rds_connect_complete(conn);
 137 }
 138
 139 static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
 140                         struct rdma_conn_param *conn_param,
 141                         struct rds_ib_connect_private *dp,
 142                         u32 protocol_version)
 143 {
 144         memset(conn_param, 0, sizeof(struct rdma_conn_param));
 145         /* XXX tune these? */
 146         conn_param->responder_resources = 1;
 147         conn_param->initiator_depth = 1;
 148         conn_param->retry_count = 7;
 149         conn_param->rnr_retry_count = 7;
 150
 151         if (dp) {
 152                 struct rds_ib_connection *ic = conn->c_transport_data;
 153
 154                 memset(dp, 0, sizeof(*dp));
 155                 dp->dp_saddr = conn->c_laddr;
 156                 dp->dp_daddr = conn->c_faddr;
 157                 dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
 158                 dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
 159                 dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
 160                 dp->dp_ack_seq = rds_ib_piggyb_ack(ic);
 161
 162                 /* Advertise flow control */
 163                 if (ic->i_flowctl) {
 164                         unsigned int credits;
 165
 166                         credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
 167                         dp->dp_credit = cpu_to_be32(credits);
 168                         atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
 169                 }
 170
 171                 conn_param->private_data = dp;
 172                 conn_param->private_data_len = sizeof(*dp);
 173         }
 174 }
 175
 176 static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
 177 {
 178         rdsdebug("event %u data %p\n", event->event, data);
 179 }
 180
 181 static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
 182 {
 183         struct rds_connection *conn = data;
 184         struct rds_ib_connection *ic = conn->c_transport_data;
 185
 186         rdsdebug("conn %p ic %p event %u\n", conn, ic, event->event);
 187
 188         switch (event->event) {
 189         case IB_EVENT_COMM_EST:
 190                 rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
 191                 break;
 192         default:
 193                 printk(KERN_WARNING "RDS/ib: unhandled QP event %u "
 194                        "on connection to %pI4\n", event->event,
 195                        &conn->c_faddr);
 196                 break;
 197         }
 198 }
 199
 200 /*
 201  * This needs to be very careful to not leave IS_ERR pointers around for
 202  * cleanup to trip over.
 203  */
 204 static int rds_ib_setup_qp(struct rds_connection *conn)
 205 {
 206         struct rds_ib_connection *ic = conn->c_transport_data;
 207         struct ib_device *dev = ic->i_cm_id->device;
 208         struct ib_qp_init_attr attr;
 209         struct rds_ib_device *rds_ibdev;
 210         int ret;
 211
 212         /* rds_ib_add_one creates a rds_ib_device object per IB device,
 213          * and allocates a protection domain, memory range and FMR pool
 214          * for each.  If that fails for any reason, it will not register
 215          * the rds_ibdev at all.
 216          */
 217         rds_ibdev = ib_get_client_data(dev, &rds_ib_client);
 218         if (rds_ibdev == NULL) {
 219                 if (printk_ratelimit())
 220                         printk(KERN_NOTICE "RDS/IB: No client_data for device %s\n",
 221                                         dev->name);
 222                 return -EOPNOTSUPP;
 223         }
 224
 225         if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
 226                 rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
 227         if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
 228                 rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
 229
 230         /* Protection domain and memory range */
 231         ic->i_pd = rds_ibdev->pd;
 232         ic->i_mr = rds_ibdev->mr;
 233
 234         ic->i_send_cq = ib_create_cq(dev, rds_ib_send_cq_comp_handler,
 235                                      rds_ib_cq_event_handler, conn,
 236                                      ic->i_send_ring.w_nr + 1, 0);
 237         if (IS_ERR(ic->i_send_cq)) {
 238                 ret = PTR_ERR(ic->i_send_cq);
 239                 ic->i_send_cq = NULL;
 240                 rdsdebug("ib_create_cq send failed: %d\n", ret);
 241                 goto out;
 242         }
 243
 244         ic->i_recv_cq = ib_create_cq(dev, rds_ib_recv_cq_comp_handler,
 245                                      rds_ib_cq_event_handler, conn,
 246                                      ic->i_recv_ring.w_nr, 0);
 247         if (IS_ERR(ic->i_recv_cq)) {
 248                 ret = PTR_ERR(ic->i_recv_cq);
 249                 ic->i_recv_cq = NULL;
 250                 rdsdebug("ib_create_cq recv failed: %d\n", ret);
 251                 goto out;
 252         }
 253
 254         ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
 255         if (ret) {
 256                 rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
 257                 goto out;
 258         }
 259
 260         ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
 261         if (ret) {
 262                 rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
 263                 goto out;
 264         }
 265
 266         /* XXX negotiate max send/recv with remote? */
 267         memset(&attr, 0, sizeof(attr));
 268         attr.event_handler = rds_ib_qp_event_handler;
 269         attr.qp_context = conn;
 270         /* + 1 to allow for the single ack message */
 271         attr.cap.max_send_wr = ic->i_send_ring.w_nr + 1;
 272         attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
 273         attr.cap.max_send_sge = rds_ibdev->max_sge;
 274         attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
 275         attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 276         attr.qp_type = IB_QPT_RC;
 277         attr.send_cq = ic->i_send_cq;
 278         attr.recv_cq = ic->i_recv_cq;
 279
 280         /*
 281          * XXX this can fail if max_*_wr is too large?  Are we supposed
 282          * to back off until we get a value that the hardware can support?
 283          */
 284         ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
 285         if (ret) {
 286                 rdsdebug("rdma_create_qp failed: %d\n", ret);
 287                 goto out;
 288         }
 289
 290         ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
 291                                            ic->i_send_ring.w_nr *
 292                                                 sizeof(struct rds_header),
 293                                            &ic->i_send_hdrs_dma, GFP_KERNEL);
 294         if (ic->i_send_hdrs == NULL) {
 295                 ret = -ENOMEM;
 296                 rdsdebug("ib_dma_alloc_coherent send failed\n");
 297                 goto out;
 298         }
 299
 300         ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
 301                                            ic->i_recv_ring.w_nr *
 302                                                 sizeof(struct rds_header),
 303                                            &ic->i_recv_hdrs_dma, GFP_KERNEL);
 304         if (ic->i_recv_hdrs == NULL) {
 305                 ret = -ENOMEM;
 306                 rdsdebug("ib_dma_alloc_coherent recv failed\n");
 307                 goto out;
 308         }
 309
 310         ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
 311                                        &ic->i_ack_dma, GFP_KERNEL);
 312         if (ic->i_ack == NULL) {
 313                 ret = -ENOMEM;
 314                 rdsdebug("ib_dma_alloc_coherent ack failed\n");
 315                 goto out;
 316         }
 317
 318         ic->i_sends = vmalloc(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work));
 319         if (ic->i_sends == NULL) {
 320                 ret = -ENOMEM;
 321                 rdsdebug("send allocation failed\n");
 322                 goto out;
 323         }
 324         rds_ib_send_init_ring(ic);
 325
 326         ic->i_recvs = vmalloc(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work));
 327         if (ic->i_recvs == NULL) {
 328                 ret = -ENOMEM;
 329                 rdsdebug("recv allocation failed\n");
 330                 goto out;
 331         }
 332
 333         rds_ib_recv_init_ring(ic);
 334         rds_ib_recv_init_ack(ic);
 335
 336         /* Post receive buffers - as a side effect, this will update
 337          * the posted credit count. */
 338         rds_ib_recv_refill(conn, GFP_KERNEL, GFP_HIGHUSER, 1);
 339
 340         rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
 341                  ic->i_send_cq, ic->i_recv_cq);
 342
 343 out:
 344         return ret;
 345 }
 346
 347 static u32 rds_ib_protocol_compatible(const struct rds_ib_connect_private *dp)
 348 {
 349         u16 common;
 350         u32 version = 0;
 351
 352         /* rdma_cm private data is odd - when there is any private data in the
 353          * request, we will be given a pretty large buffer without telling us the
 354          * original size. The only way to tell the difference is by looking at
 355          * the contents, which are initialized to zero.
 356          * If the protocol version fields aren't set, this is a connection attempt
 357          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
 358          * We really should have changed this for OFED 1.3 :-( */
 359         if (dp->dp_protocol_major == 0)
 360                 return RDS_PROTOCOL_3_0;
 361
 362         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
 363         if (dp->dp_protocol_major == 3 && common) {
 364                 version = RDS_PROTOCOL_3_0;
 365                 while ((common >>= 1) != 0)
 366                         version++;
 367         } else if (printk_ratelimit()) {
 368                 printk(KERN_NOTICE "RDS: Connection from %pI4 using "
 369                         "incompatible protocol version %u.%u\n",
 370                         &dp->dp_saddr,
 371                         dp->dp_protocol_major,
 372                         dp->dp_protocol_minor);
 373         }
 374         return version;
 375 }
 376
 377 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 378                                     struct rdma_cm_event *event)
 379 {
 380         __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
 381         __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
 382         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
 383         struct rds_ib_connect_private dp_rep;
 384         struct rds_connection *conn = NULL;
 385         struct rds_ib_connection *ic = NULL;
 386         struct rdma_conn_param conn_param;
 387         u32 version;
 388         int err, destroy = 1;
 389
 390         /* Check whether the remote protocol version matches ours. */
 391         version = rds_ib_protocol_compatible(dp);
 392         if (!version)
 393                 goto out;
 394
 395         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
 396                  "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
 397                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
 398                  (unsigned long long)be64_to_cpu(lguid),
 399                  (unsigned long long)be64_to_cpu(fguid));
 400
 401         conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
 402                                GFP_KERNEL);
 403         if (IS_ERR(conn)) {
 404                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 405                 conn = NULL;
 406                 goto out;
 407         }
 408
 409         /*
 410          * The connection request may occur while the
 411          * previous connection exist, e.g. in case of failover.
 412          * But as connections may be initiated simultaneously
 413          * by both hosts, we have a random backoff mechanism -
 414          * see the comment above rds_queue_reconnect()
 415          */
 416         mutex_lock(&conn->c_cm_lock);
 417         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 418                 if (rds_conn_state(conn) == RDS_CONN_UP) {
 419                         rdsdebug("incoming connect while connecting\n");
 420                         rds_conn_drop(conn);
 421                         rds_ib_stats_inc(s_ib_listen_closed_stale);
 422                 } else
 423                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
 424                         /* Wait and see - our connect may still be succeeding */
 425                         rds_ib_stats_inc(s_ib_connect_raced);
 426                 }
 427                 mutex_unlock(&conn->c_cm_lock);
 428                 goto out;
 429         }
 430
 431         ic = conn->c_transport_data;
 432
 433         rds_ib_set_protocol(conn, version);
 434         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 435
 436         /* If the peer gave us the last packet it saw, process this as if
 437          * we had received a regular ACK. */
 438         if (dp->dp_ack_seq)
 439                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 440
 441         BUG_ON(cm_id->context);
 442         BUG_ON(ic->i_cm_id);
 443
 444         ic->i_cm_id = cm_id;
 445         cm_id->context = conn;
 446
 447         /* We got halfway through setting up the ib_connection, if we
 448          * fail now, we have to take the long route out of this mess. */
 449         destroy = 0;
 450
 451         err = rds_ib_setup_qp(conn);
 452         if (err) {
 453                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
 454                 goto out;
 455         }
 456
 457         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version);
 458
 459         /* rdma_accept() calls rdma_reject() internally if it fails */
 460         err = rdma_accept(cm_id, &conn_param);
 461         mutex_unlock(&conn->c_cm_lock);
 462         if (err) {
 463                 rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
 464                 goto out;
 465         }
 466
 467         return 0;
 468
 469 out:
 470         rdma_reject(cm_id, NULL, 0);
 471         return destroy;
 472 }
 473
 474
 475 int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
 476 {
 477         struct rds_connection *conn = cm_id->context;
 478         struct rds_ib_connection *ic = conn->c_transport_data;
 479         struct rdma_conn_param conn_param;
 480         struct rds_ib_connect_private dp;
 481         int ret;
 482
 483         /* If the peer doesn't do protocol negotiation, we must
 484          * default to RDSv3.0 */
 485         rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
 486         ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
 487
 488         ret = rds_ib_setup_qp(conn);
 489         if (ret) {
 490                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
 491                 goto out;
 492         }
 493
 494         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION);
 495
 496         ret = rdma_connect(cm_id, &conn_param);
 497         if (ret)
 498                 rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
 499
 500 out:
 501         /* Beware - returning non-zero tells the rdma_cm to destroy
 502          * the cm_id. We should certainly not do it as long as we still
 503          * "own" the cm_id. */
 504         if (ret) {
 505                 if (ic->i_cm_id == cm_id)
 506                         ret = 0;
 507         }
 508         return ret;
 509 }
 510
 511 int rds_ib_conn_connect(struct rds_connection *conn)
 512 {
 513         struct rds_ib_connection *ic = conn->c_transport_data;
 514         struct sockaddr_in src, dest;
 515         int ret;
 516
 517         /* XXX I wonder what affect the port space has */
 518         /* delegate cm event handler to rdma_transport */
 519         ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
 520                                      RDMA_PS_TCP);
 521         if (IS_ERR(ic->i_cm_id)) {
 522                 ret = PTR_ERR(ic->i_cm_id);
 523                 ic->i_cm_id = NULL;
 524                 rdsdebug("rdma_create_id() failed: %d\n", ret);
 525                 goto out;
 526         }
 527
 528         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
 529
 530         src.sin_family = AF_INET;
 531         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
 532         src.sin_port = (__force u16)htons(0);
 533
 534         dest.sin_family = AF_INET;
 535         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 536         dest.sin_port = (__force u16)htons(RDS_PORT);
 537
 538         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
 539                                 (struct sockaddr *)&dest,
 540                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
 541         if (ret) {
 542                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
 543                          ret);
 544                 rdma_destroy_id(ic->i_cm_id);
 545                 ic->i_cm_id = NULL;
 546         }
 547
 548 out:
 549         return ret;
 550 }
 551
 552 /*
 553  * This is so careful about only cleaning up resources that were built up
 554  * so that it can be called at any point during startup.  In fact it
 555  * can be called multiple times for a given connection.
 556  */
 557 void rds_ib_conn_shutdown(struct rds_connection *conn)
 558 {
 559         struct rds_ib_connection *ic = conn->c_transport_data;
 560         int err = 0;
 561
 562         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
 563                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
 564                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
 565
 566         if (ic->i_cm_id) {
 567                 struct ib_device *dev = ic->i_cm_id->device;
 568
 569                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
 570                 err = rdma_disconnect(ic->i_cm_id);
 571                 if (err) {
 572                         /* Actually this may happen quite frequently, when
 573                          * an outgoing connect raced with an incoming connect.
 574                          */
 575                         rdsdebug("failed to disconnect, cm: %p err %d\n",
 576                                 ic->i_cm_id, err);
 577                 }
 578
 579                 wait_event(rds_ib_ring_empty_wait,
 580                         rds_ib_ring_empty(&ic->i_send_ring) &&
 581                         rds_ib_ring_empty(&ic->i_recv_ring));
 582
 583                 if (ic->i_send_hdrs)
 584                         ib_dma_free_coherent(dev,
 585                                            ic->i_send_ring.w_nr *
 586                                                 sizeof(struct rds_header),
 587                                            ic->i_send_hdrs,
 588                                            ic->i_send_hdrs_dma);
 589
 590                 if (ic->i_recv_hdrs)
 591                         ib_dma_free_coherent(dev,
 592                                            ic->i_recv_ring.w_nr *
 593                                                 sizeof(struct rds_header),
 594                                            ic->i_recv_hdrs,
 595                                            ic->i_recv_hdrs_dma);
 596
 597                 if (ic->i_ack)
 598                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
 599                                              ic->i_ack, ic->i_ack_dma);
 600
 601                 if (ic->i_sends)
 602                         rds_ib_send_clear_ring(ic);
 603                 if (ic->i_recvs)
 604                         rds_ib_recv_clear_ring(ic);
 605
 606                 if (ic->i_cm_id->qp)
 607                         rdma_destroy_qp(ic->i_cm_id);
 608                 if (ic->i_send_cq)
 609                         ib_destroy_cq(ic->i_send_cq);
 610                 if (ic->i_recv_cq)
 611                         ib_destroy_cq(ic->i_recv_cq);
 612                 rdma_destroy_id(ic->i_cm_id);
 613
 614                 /*
 615                  * Move connection back to the nodev list.
 616                  */
 617                 if (ic->rds_ibdev)
 618                         rds_ib_remove_conn(ic->rds_ibdev, conn);
 619
 620                 ic->i_cm_id = NULL;
 621                 ic->i_pd = NULL;
 622                 ic->i_mr = NULL;
 623                 ic->i_send_cq = NULL;
 624                 ic->i_recv_cq = NULL;
 625                 ic->i_send_hdrs = NULL;
 626                 ic->i_recv_hdrs = NULL;
 627                 ic->i_ack = NULL;
 628         }
 629         BUG_ON(ic->rds_ibdev);
 630
 631         /* Clear pending transmit */
 632         if (ic->i_rm) {
 633                 rds_message_put(ic->i_rm);
 634                 ic->i_rm = NULL;
 635         }
 636
 637         /* Clear the ACK state */
 638         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
 639 #ifdef KERNEL_HAS_ATOMIC64
 640         atomic64_set(&ic->i_ack_next, 0);
 641 #else
 642         ic->i_ack_next = 0;
 643 #endif
 644         ic->i_ack_recv = 0;
 645
 646         /* Clear flow control state */
 647         ic->i_flowctl = 0;
 648         atomic_set(&ic->i_credits, 0);
 649
 650         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 651         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 652
 653         if (ic->i_ibinc) {
 654                 rds_inc_put(&ic->i_ibinc->ii_inc);
 655                 ic->i_ibinc = NULL;
 656         }
 657
 658         vfree(ic->i_sends);
 659         ic->i_sends = NULL;
 660         vfree(ic->i_recvs);
 661         ic->i_recvs = NULL;
 662 }
 663
 664 int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 665 {
 666         struct rds_ib_connection *ic;
 667         unsigned long flags;
 668
 669         /* XXX too lazy? */
 670         ic = kzalloc(sizeof(struct rds_ib_connection), GFP_KERNEL);
 671         if (ic == NULL)
 672                 return -ENOMEM;
 673
 674         INIT_LIST_HEAD(&ic->ib_node);
 675         mutex_init(&ic->i_recv_mutex);
 676 #ifndef KERNEL_HAS_ATOMIC64
 677         spin_lock_init(&ic->i_ack_lock);
 678 #endif
 679
 680         /*
 681          * rds_ib_conn_shutdown() waits for these to be emptied so they
 682          * must be initialized before it can be called.
 683          */
 684         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
 685         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
 686
 687         ic->conn = conn;
 688         conn->c_transport_data = ic;
 689
 690         spin_lock_irqsave(&ib_nodev_conns_lock, flags);
 691         list_add_tail(&ic->ib_node, &ib_nodev_conns);
 692         spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
 693
 694
 695         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
 696         return 0;
 697 }
 698
 699 /*
 700  * Free a connection. Connection must be shut down and not set for reconnect.
 701  */
 702 void rds_ib_conn_free(void *arg)
 703 {
 704         struct rds_ib_connection *ic = arg;
 705         spinlock_t      *lock_ptr;
 706
 707         rdsdebug("ic %p\n", ic);
 708
 709         /*
 710          * Conn is either on a dev's list or on the nodev list.
 711          * A race with shutdown() or connect() would cause problems
 712          * (since rds_ibdev would change) but that should never happen.
 713          */
 714         lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
 715
 716         spin_lock_irq(lock_ptr);
 717         list_del(&ic->ib_node);
 718         spin_unlock_irq(lock_ptr);
 719
 720         kfree(ic);
 721 }
 722
 723
 724 /*
 725  * An error occurred on the connection
 726  */
 727 void
 728 __rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
 729 {
 730         va_list ap;
 731
 732         rds_conn_drop(conn);
 733
 734         va_start(ap, fmt);
 735         vprintk(fmt, ap);
 736         va_end(ap);
 737 }