release/src-rt-6.x.4708/linux/linux-2.6.36/net/rds/iw_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
  38 #include "rds.h"
  39 #include "iw.h"
  40
  41 /*
  42  * Set the selected protocol version
  43  */
  44 static void rds_iw_set_protocol(struct rds_connection *conn, unsigned int version)
  45 {
  46         conn->c_version = version;
  47 }
  48
  49 /*
  50  * Set up flow control
  51  */
  52 static void rds_iw_set_flow_control(struct rds_connection *conn, u32 credits)
  53 {
  54         struct rds_iw_connection *ic = conn->c_transport_data;
  55
  56         if (rds_iw_sysctl_flow_control && credits != 0) {
  57                 /* We're doing flow control */
  58                 ic->i_flowctl = 1;
  59                 rds_iw_send_add_credits(conn, credits);
  60         } else {
  61                 ic->i_flowctl = 0;
  62         }
  63 }
  64
  65 /*
  66  * Connection established.
  67  * We get here for both outgoing and incoming connection.
  68  */
  69 void rds_iw_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
  70 {
  71         const struct rds_iw_connect_private *dp = NULL;
  72         struct rds_iw_connection *ic = conn->c_transport_data;
  73         struct rds_iw_device *rds_iwdev;
  74         int err;
  75
  76         if (event->param.conn.private_data_len) {
  77                 dp = event->param.conn.private_data;
  78
  79                 rds_iw_set_protocol(conn,
  80                                 RDS_PROTOCOL(dp->dp_protocol_major,
  81                                         dp->dp_protocol_minor));
  82                 rds_iw_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
  83         }
  84
  85         /* update ib_device with this local ipaddr & conn */
  86         rds_iwdev = ib_get_client_data(ic->i_cm_id->device, &rds_iw_client);
  87         err = rds_iw_update_cm_id(rds_iwdev, ic->i_cm_id);
  88         if (err)
  89                 printk(KERN_ERR "rds_iw_update_ipaddr failed (%d)\n", err);
  90         rds_iw_add_conn(rds_iwdev, conn);
  91
  92         /* If the peer gave us the last packet it saw, process this as if
  93          * we had received a regular ACK. */
  94         if (dp && dp->dp_ack_seq)
  95                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
  96
  97         printk(KERN_NOTICE "RDS/IW: connected to %pI4<->%pI4 version %u.%u%s\n",
  98                         &conn->c_laddr, &conn->c_faddr,
  99                         RDS_PROTOCOL_MAJOR(conn->c_version),
 100                         RDS_PROTOCOL_MINOR(conn->c_version),
 101                         ic->i_flowctl ? ", flow control" : "");
 102
 103         rds_connect_complete(conn);
 104 }
 105
 106 static void rds_iw_cm_fill_conn_param(struct rds_connection *conn,
 107                         struct rdma_conn_param *conn_param,
 108                         struct rds_iw_connect_private *dp,
 109                         u32 protocol_version)
 110 {
 111         struct rds_iw_connection *ic = conn->c_transport_data;
 112
 113         memset(conn_param, 0, sizeof(struct rdma_conn_param));
 114         conn_param->responder_resources = 1;
 115         conn_param->initiator_depth = 1;
 116
 117         if (dp) {
 118                 memset(dp, 0, sizeof(*dp));
 119                 dp->dp_saddr = conn->c_laddr;
 120                 dp->dp_daddr = conn->c_faddr;
 121                 dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
 122                 dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
 123                 dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IW_SUPPORTED_PROTOCOLS);
 124                 dp->dp_ack_seq = rds_iw_piggyb_ack(ic);
 125
 126                 /* Advertise flow control */
 127                 if (ic->i_flowctl) {
 128                         unsigned int credits;
 129
 130                         credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
 131                         dp->dp_credit = cpu_to_be32(credits);
 132                         atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
 133                 }
 134
 135                 conn_param->private_data = dp;
 136                 conn_param->private_data_len = sizeof(*dp);
 137         }
 138 }
 139
 140 static void rds_iw_cq_event_handler(struct ib_event *event, void *data)
 141 {
 142         rdsdebug("event %u data %p\n", event->event, data);
 143 }
 144
 145 static void rds_iw_qp_event_handler(struct ib_event *event, void *data)
 146 {
 147         struct rds_connection *conn = data;
 148         struct rds_iw_connection *ic = conn->c_transport_data;
 149
 150         rdsdebug("conn %p ic %p event %u\n", conn, ic, event->event);
 151
 152         switch (event->event) {
 153         case IB_EVENT_COMM_EST:
 154                 rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
 155                 break;
 156         case IB_EVENT_QP_REQ_ERR:
 157         case IB_EVENT_QP_FATAL:
 158         default:
 159                 rdsdebug("Fatal QP Event %u "
 160                         "- connection %pI4->%pI4, reconnecting\n",
 161                         event->event, &conn->c_laddr,
 162                         &conn->c_faddr);
 163                 rds_conn_drop(conn);
 164                 break;
 165         }
 166 }
 167
 168 /*
 169  * Create a QP
 170  */
 171 static int rds_iw_init_qp_attrs(struct ib_qp_init_attr *attr,
 172                 struct rds_iw_device *rds_iwdev,
 173                 struct rds_iw_work_ring *send_ring,
 174                 void (*send_cq_handler)(struct ib_cq *, void *),
 175                 struct rds_iw_work_ring *recv_ring,
 176                 void (*recv_cq_handler)(struct ib_cq *, void *),
 177                 void *context)
 178 {
 179         struct ib_device *dev = rds_iwdev->dev;
 180         unsigned int send_size, recv_size;
 181         int ret;
 182
 183         /* The offset of 1 is to accomodate the additional ACK WR. */
 184         send_size = min_t(unsigned int, rds_iwdev->max_wrs, rds_iw_sysctl_max_send_wr + 1);
 185         recv_size = min_t(unsigned int, rds_iwdev->max_wrs, rds_iw_sysctl_max_recv_wr + 1);
 186         rds_iw_ring_resize(send_ring, send_size - 1);
 187         rds_iw_ring_resize(recv_ring, recv_size - 1);
 188
 189         memset(attr, 0, sizeof(*attr));
 190         attr->event_handler = rds_iw_qp_event_handler;
 191         attr->qp_context = context;
 192         attr->cap.max_send_wr = send_size;
 193         attr->cap.max_recv_wr = recv_size;
 194         attr->cap.max_send_sge = rds_iwdev->max_sge;
 195         attr->cap.max_recv_sge = RDS_IW_RECV_SGE;
 196         attr->sq_sig_type = IB_SIGNAL_REQ_WR;
 197         attr->qp_type = IB_QPT_RC;
 198
 199         attr->send_cq = ib_create_cq(dev, send_cq_handler,
 200                                      rds_iw_cq_event_handler,
 201                                      context, send_size, 0);
 202         if (IS_ERR(attr->send_cq)) {
 203                 ret = PTR_ERR(attr->send_cq);
 204                 attr->send_cq = NULL;
 205                 rdsdebug("ib_create_cq send failed: %d\n", ret);
 206                 goto out;
 207         }
 208
 209         attr->recv_cq = ib_create_cq(dev, recv_cq_handler,
 210                                      rds_iw_cq_event_handler,
 211                                      context, recv_size, 0);
 212         if (IS_ERR(attr->recv_cq)) {
 213                 ret = PTR_ERR(attr->recv_cq);
 214                 attr->recv_cq = NULL;
 215                 rdsdebug("ib_create_cq send failed: %d\n", ret);
 216                 goto out;
 217         }
 218
 219         ret = ib_req_notify_cq(attr->send_cq, IB_CQ_NEXT_COMP);
 220         if (ret) {
 221                 rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
 222                 goto out;
 223         }
 224
 225         ret = ib_req_notify_cq(attr->recv_cq, IB_CQ_SOLICITED);
 226         if (ret) {
 227                 rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
 228                 goto out;
 229         }
 230
 231 out:
 232         if (ret) {
 233                 if (attr->send_cq)
 234                         ib_destroy_cq(attr->send_cq);
 235                 if (attr->recv_cq)
 236                         ib_destroy_cq(attr->recv_cq);
 237         }
 238         return ret;
 239 }
 240
 241 /*
 242  * This needs to be very careful to not leave IS_ERR pointers around for
 243  * cleanup to trip over.
 244  */
 245 static int rds_iw_setup_qp(struct rds_connection *conn)
 246 {
 247         struct rds_iw_connection *ic = conn->c_transport_data;
 248         struct ib_device *dev = ic->i_cm_id->device;
 249         struct ib_qp_init_attr attr;
 250         struct rds_iw_device *rds_iwdev;
 251         int ret;
 252
 253         /* rds_iw_add_one creates a rds_iw_device object per IB device,
 254          * and allocates a protection domain, memory range and MR pool
 255          * for each.  If that fails for any reason, it will not register
 256          * the rds_iwdev at all.
 257          */
 258         rds_iwdev = ib_get_client_data(dev, &rds_iw_client);
 259         if (rds_iwdev == NULL) {
 260                 if (printk_ratelimit())
 261                         printk(KERN_NOTICE "RDS/IW: No client_data for device %s\n",
 262                                         dev->name);
 263                 return -EOPNOTSUPP;
 264         }
 265
 266         /* Protection domain and memory range */
 267         ic->i_pd = rds_iwdev->pd;
 268         ic->i_mr = rds_iwdev->mr;
 269
 270         ret = rds_iw_init_qp_attrs(&attr, rds_iwdev,
 271                         &ic->i_send_ring, rds_iw_send_cq_comp_handler,
 272                         &ic->i_recv_ring, rds_iw_recv_cq_comp_handler,
 273                         conn);
 274         if (ret < 0)
 275                 goto out;
 276
 277         ic->i_send_cq = attr.send_cq;
 278         ic->i_recv_cq = attr.recv_cq;
 279
 280         ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
 281         if (ret) {
 282                 rdsdebug("rdma_create_qp failed: %d\n", ret);
 283                 goto out;
 284         }
 285
 286         ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
 287                                            ic->i_send_ring.w_nr *
 288                                                 sizeof(struct rds_header),
 289                                            &ic->i_send_hdrs_dma, GFP_KERNEL);
 290         if (ic->i_send_hdrs == NULL) {
 291                 ret = -ENOMEM;
 292                 rdsdebug("ib_dma_alloc_coherent send failed\n");
 293                 goto out;
 294         }
 295
 296         ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
 297                                            ic->i_recv_ring.w_nr *
 298                                                 sizeof(struct rds_header),
 299                                            &ic->i_recv_hdrs_dma, GFP_KERNEL);
 300         if (ic->i_recv_hdrs == NULL) {
 301                 ret = -ENOMEM;
 302                 rdsdebug("ib_dma_alloc_coherent recv failed\n");
 303                 goto out;
 304         }
 305
 306         ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
 307                                        &ic->i_ack_dma, GFP_KERNEL);
 308         if (ic->i_ack == NULL) {
 309                 ret = -ENOMEM;
 310                 rdsdebug("ib_dma_alloc_coherent ack failed\n");
 311                 goto out;
 312         }
 313
 314         ic->i_sends = vmalloc(ic->i_send_ring.w_nr * sizeof(struct rds_iw_send_work));
 315         if (ic->i_sends == NULL) {
 316                 ret = -ENOMEM;
 317                 rdsdebug("send allocation failed\n");
 318                 goto out;
 319         }
 320         rds_iw_send_init_ring(ic);
 321
 322         ic->i_recvs = vmalloc(ic->i_recv_ring.w_nr * sizeof(struct rds_iw_recv_work));
 323         if (ic->i_recvs == NULL) {
 324                 ret = -ENOMEM;
 325                 rdsdebug("recv allocation failed\n");
 326                 goto out;
 327         }
 328
 329         rds_iw_recv_init_ring(ic);
 330         rds_iw_recv_init_ack(ic);
 331
 332         /* Post receive buffers - as a side effect, this will update
 333          * the posted credit count. */
 334         rds_iw_recv_refill(conn, GFP_KERNEL, GFP_HIGHUSER, 1);
 335
 336         rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
 337                  ic->i_send_cq, ic->i_recv_cq);
 338
 339 out:
 340         return ret;
 341 }
 342
 343 static u32 rds_iw_protocol_compatible(const struct rds_iw_connect_private *dp)
 344 {
 345         u16 common;
 346         u32 version = 0;
 347
 348         /* rdma_cm private data is odd - when there is any private data in the
 349          * request, we will be given a pretty large buffer without telling us the
 350          * original size. The only way to tell the difference is by looking at
 351          * the contents, which are initialized to zero.
 352          * If the protocol version fields aren't set, this is a connection attempt
 353          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
 354          * We really should have changed this for OFED 1.3 :-( */
 355         if (dp->dp_protocol_major == 0)
 356                 return RDS_PROTOCOL_3_0;
 357
 358         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IW_SUPPORTED_PROTOCOLS;
 359         if (dp->dp_protocol_major == 3 && common) {
 360                 version = RDS_PROTOCOL_3_0;
 361                 while ((common >>= 1) != 0)
 362                         version++;
 363         } else if (printk_ratelimit()) {
 364                 printk(KERN_NOTICE "RDS: Connection from %pI4 using "
 365                         "incompatible protocol version %u.%u\n",
 366                         &dp->dp_saddr,
 367                         dp->dp_protocol_major,
 368                         dp->dp_protocol_minor);
 369         }
 370         return version;
 371 }
 372
 373 int rds_iw_cm_handle_connect(struct rdma_cm_id *cm_id,
 374                                     struct rdma_cm_event *event)
 375 {
 376         const struct rds_iw_connect_private *dp = event->param.conn.private_data;
 377         struct rds_iw_connect_private dp_rep;
 378         struct rds_connection *conn = NULL;
 379         struct rds_iw_connection *ic = NULL;
 380         struct rdma_conn_param conn_param;
 381         struct rds_iw_device *rds_iwdev;
 382         u32 version;
 383         int err, destroy = 1;
 384
 385         /* Check whether the remote protocol version matches ours. */
 386         version = rds_iw_protocol_compatible(dp);
 387         if (!version)
 388                 goto out;
 389
 390         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u\n",
 391                  &dp->dp_saddr, &dp->dp_daddr,
 392                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version));
 393
 394         conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_iw_transport,
 395                                GFP_KERNEL);
 396         if (IS_ERR(conn)) {
 397                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 398                 conn = NULL;
 399                 goto out;
 400         }
 401
 402         /*
 403          * The connection request may occur while the
 404          * previous connection exist, e.g. in case of failover.
 405          * But as connections may be initiated simultaneously
 406          * by both hosts, we have a random backoff mechanism -
 407          * see the comment above rds_queue_reconnect()
 408          */
 409         mutex_lock(&conn->c_cm_lock);
 410         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 411                 if (rds_conn_state(conn) == RDS_CONN_UP) {
 412                         rdsdebug("incoming connect while connecting\n");
 413                         rds_conn_drop(conn);
 414                         rds_iw_stats_inc(s_iw_listen_closed_stale);
 415                 } else
 416                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
 417                         /* Wait and see - our connect may still be succeeding */
 418                         rds_iw_stats_inc(s_iw_connect_raced);
 419                 }
 420                 mutex_unlock(&conn->c_cm_lock);
 421                 goto out;
 422         }
 423
 424         ic = conn->c_transport_data;
 425
 426         rds_iw_set_protocol(conn, version);
 427         rds_iw_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
 428
 429         /* If the peer gave us the last packet it saw, process this as if
 430          * we had received a regular ACK. */
 431         if (dp->dp_ack_seq)
 432                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 433
 434         BUG_ON(cm_id->context);
 435         BUG_ON(ic->i_cm_id);
 436
 437         ic->i_cm_id = cm_id;
 438         cm_id->context = conn;
 439
 440         rds_iwdev = ib_get_client_data(cm_id->device, &rds_iw_client);
 441         ic->i_dma_local_lkey = rds_iwdev->dma_local_lkey;
 442
 443         /* We got halfway through setting up the ib_connection, if we
 444          * fail now, we have to take the long route out of this mess. */
 445         destroy = 0;
 446
 447         err = rds_iw_setup_qp(conn);
 448         if (err) {
 449                 rds_iw_conn_error(conn, "rds_iw_setup_qp failed (%d)\n", err);
 450                 mutex_unlock(&conn->c_cm_lock);
 451                 goto out;
 452         }
 453
 454         rds_iw_cm_fill_conn_param(conn, &conn_param, &dp_rep, version);
 455
 456         /* rdma_accept() calls rdma_reject() internally if it fails */
 457         err = rdma_accept(cm_id, &conn_param);
 458         mutex_unlock(&conn->c_cm_lock);
 459         if (err) {
 460                 rds_iw_conn_error(conn, "rdma_accept failed (%d)\n", err);
 461                 goto out;
 462         }
 463
 464         return 0;
 465
 466 out:
 467         rdma_reject(cm_id, NULL, 0);
 468         return destroy;
 469 }
 470
 471
 472 int rds_iw_cm_initiate_connect(struct rdma_cm_id *cm_id)
 473 {
 474         struct rds_connection *conn = cm_id->context;
 475         struct rds_iw_connection *ic = conn->c_transport_data;
 476         struct rdma_conn_param conn_param;
 477         struct rds_iw_connect_private dp;
 478         int ret;
 479
 480         /* If the peer doesn't do protocol negotiation, we must
 481          * default to RDSv3.0 */
 482         rds_iw_set_protocol(conn, RDS_PROTOCOL_3_0);
 483         ic->i_flowctl = rds_iw_sysctl_flow_control;     /* advertise flow control */
 484
 485         ret = rds_iw_setup_qp(conn);
 486         if (ret) {
 487                 rds_iw_conn_error(conn, "rds_iw_setup_qp failed (%d)\n", ret);
 488                 goto out;
 489         }
 490
 491         rds_iw_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION);
 492
 493         ret = rdma_connect(cm_id, &conn_param);
 494         if (ret)
 495                 rds_iw_conn_error(conn, "rdma_connect failed (%d)\n", ret);
 496
 497 out:
 498         /* Beware - returning non-zero tells the rdma_cm to destroy
 499          * the cm_id. We should certainly not do it as long as we still
 500          * "own" the cm_id. */
 501         if (ret) {
 502                 struct rds_iw_connection *ic = conn->c_transport_data;
 503
 504                 if (ic->i_cm_id == cm_id)
 505                         ret = 0;
 506         }
 507         return ret;
 508 }
 509
 510 int rds_iw_conn_connect(struct rds_connection *conn)
 511 {
 512         struct rds_iw_connection *ic = conn->c_transport_data;
 513         struct rds_iw_device *rds_iwdev;
 514         struct sockaddr_in src, dest;
 515         int ret;
 516
 517         /* delegate cm event handler to rdma_transport */
 518         ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
 519                                      RDMA_PS_TCP);
 520         if (IS_ERR(ic->i_cm_id)) {
 521                 ret = PTR_ERR(ic->i_cm_id);
 522                 ic->i_cm_id = NULL;
 523                 rdsdebug("rdma_create_id() failed: %d\n", ret);
 524                 goto out;
 525         }
 526
 527         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
 528
 529         src.sin_family = AF_INET;
 530         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
 531         src.sin_port = (__force u16)htons(0);
 532
 533         /* First, bind to the local address and device. */
 534         ret = rdma_bind_addr(ic->i_cm_id, (struct sockaddr *) &src);
 535         if (ret) {
 536                 rdsdebug("rdma_bind_addr(%pI4) failed: %d\n",
 537                                 &conn->c_laddr, ret);
 538                 rdma_destroy_id(ic->i_cm_id);
 539                 ic->i_cm_id = NULL;
 540                 goto out;
 541         }
 542
 543         rds_iwdev = ib_get_client_data(ic->i_cm_id->device, &rds_iw_client);
 544         ic->i_dma_local_lkey = rds_iwdev->dma_local_lkey;
 545
 546         dest.sin_family = AF_INET;
 547         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 548         dest.sin_port = (__force u16)htons(RDS_PORT);
 549
 550         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
 551                                 (struct sockaddr *)&dest,
 552                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
 553         if (ret) {
 554                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
 555                          ret);
 556                 rdma_destroy_id(ic->i_cm_id);
 557                 ic->i_cm_id = NULL;
 558         }
 559
 560 out:
 561         return ret;
 562 }
 563
 564 /*
 565  * This is so careful about only cleaning up resources that were built up
 566  * so that it can be called at any point during startup.  In fact it
 567  * can be called multiple times for a given connection.
 568  */
 569 void rds_iw_conn_shutdown(struct rds_connection *conn)
 570 {
 571         struct rds_iw_connection *ic = conn->c_transport_data;
 572         int err = 0;
 573         struct ib_qp_attr qp_attr;
 574
 575         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
 576                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
 577                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
 578
 579         if (ic->i_cm_id) {
 580                 struct ib_device *dev = ic->i_cm_id->device;
 581
 582                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
 583                 err = rdma_disconnect(ic->i_cm_id);
 584                 if (err) {
 585                         /* Actually this may happen quite frequently, when
 586                          * an outgoing connect raced with an incoming connect.
 587                          */
 588                         rdsdebug("rds_iw_conn_shutdown: failed to disconnect,"
 589                                    " cm: %p err %d\n", ic->i_cm_id, err);
 590                 }
 591
 592                 if (ic->i_cm_id->qp) {
 593                         qp_attr.qp_state = IB_QPS_ERR;
 594                         ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
 595                 }
 596
 597                 wait_event(rds_iw_ring_empty_wait,
 598                         rds_iw_ring_empty(&ic->i_send_ring) &&
 599                         rds_iw_ring_empty(&ic->i_recv_ring));
 600
 601                 if (ic->i_send_hdrs)
 602                         ib_dma_free_coherent(dev,
 603                                            ic->i_send_ring.w_nr *
 604                                                 sizeof(struct rds_header),
 605                                            ic->i_send_hdrs,
 606                                            ic->i_send_hdrs_dma);
 607
 608                 if (ic->i_recv_hdrs)
 609                         ib_dma_free_coherent(dev,
 610                                            ic->i_recv_ring.w_nr *
 611                                                 sizeof(struct rds_header),
 612                                            ic->i_recv_hdrs,
 613                                            ic->i_recv_hdrs_dma);
 614
 615                 if (ic->i_ack)
 616                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
 617                                              ic->i_ack, ic->i_ack_dma);
 618
 619                 if (ic->i_sends)
 620                         rds_iw_send_clear_ring(ic);
 621                 if (ic->i_recvs)
 622                         rds_iw_recv_clear_ring(ic);
 623
 624                 if (ic->i_cm_id->qp)
 625                         rdma_destroy_qp(ic->i_cm_id);
 626                 if (ic->i_send_cq)
 627                         ib_destroy_cq(ic->i_send_cq);
 628                 if (ic->i_recv_cq)
 629                         ib_destroy_cq(ic->i_recv_cq);
 630
 631                 /*
 632                  * If associated with an rds_iw_device:
 633                  *      Move connection back to the nodev list.
 634                  *      Remove cm_id from the device cm_id list.
 635                  */
 636                 if (ic->rds_iwdev)
 637                         rds_iw_remove_conn(ic->rds_iwdev, conn);
 638
 639                 rdma_destroy_id(ic->i_cm_id);
 640
 641                 ic->i_cm_id = NULL;
 642                 ic->i_pd = NULL;
 643                 ic->i_mr = NULL;
 644                 ic->i_send_cq = NULL;
 645                 ic->i_recv_cq = NULL;
 646                 ic->i_send_hdrs = NULL;
 647                 ic->i_recv_hdrs = NULL;
 648                 ic->i_ack = NULL;
 649         }
 650         BUG_ON(ic->rds_iwdev);
 651
 652         /* Clear pending transmit */
 653         if (ic->i_rm) {
 654                 rds_message_put(ic->i_rm);
 655                 ic->i_rm = NULL;
 656         }
 657
 658         /* Clear the ACK state */
 659         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
 660 #ifdef KERNEL_HAS_ATOMIC64
 661         atomic64_set(&ic->i_ack_next, 0);
 662 #else
 663         ic->i_ack_next = 0;
 664 #endif
 665         ic->i_ack_recv = 0;
 666
 667         /* Clear flow control state */
 668         ic->i_flowctl = 0;
 669         atomic_set(&ic->i_credits, 0);
 670
 671         rds_iw_ring_init(&ic->i_send_ring, rds_iw_sysctl_max_send_wr);
 672         rds_iw_ring_init(&ic->i_recv_ring, rds_iw_sysctl_max_recv_wr);
 673
 674         if (ic->i_iwinc) {
 675                 rds_inc_put(&ic->i_iwinc->ii_inc);
 676                 ic->i_iwinc = NULL;
 677         }
 678
 679         vfree(ic->i_sends);
 680         ic->i_sends = NULL;
 681         vfree(ic->i_recvs);
 682         ic->i_recvs = NULL;
 683         rdsdebug("shutdown complete\n");
 684 }
 685
 686 int rds_iw_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 687 {
 688         struct rds_iw_connection *ic;
 689         unsigned long flags;
 690
 691         ic = kzalloc(sizeof(struct rds_iw_connection), GFP_KERNEL);
 692         if (ic == NULL)
 693                 return -ENOMEM;
 694
 695         INIT_LIST_HEAD(&ic->iw_node);
 696         tasklet_init(&ic->i_recv_tasklet, rds_iw_recv_tasklet_fn,
 697                      (unsigned long) ic);
 698         mutex_init(&ic->i_recv_mutex);
 699 #ifndef KERNEL_HAS_ATOMIC64
 700         spin_lock_init(&ic->i_ack_lock);
 701 #endif
 702
 703         /*
 704          * rds_iw_conn_shutdown() waits for these to be emptied so they
 705          * must be initialized before it can be called.
 706          */
 707         rds_iw_ring_init(&ic->i_send_ring, rds_iw_sysctl_max_send_wr);
 708         rds_iw_ring_init(&ic->i_recv_ring, rds_iw_sysctl_max_recv_wr);
 709
 710         ic->conn = conn;
 711         conn->c_transport_data = ic;
 712
 713         spin_lock_irqsave(&iw_nodev_conns_lock, flags);
 714         list_add_tail(&ic->iw_node, &iw_nodev_conns);
 715         spin_unlock_irqrestore(&iw_nodev_conns_lock, flags);
 716
 717
 718         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
 719         return 0;
 720 }
 721
 722 /*
 723  * Free a connection. Connection must be shut down and not set for reconnect.
 724  */
 725 void rds_iw_conn_free(void *arg)
 726 {
 727         struct rds_iw_connection *ic = arg;
 728         spinlock_t      *lock_ptr;
 729
 730         rdsdebug("ic %p\n", ic);
 731
 732         /*
 733          * Conn is either on a dev's list or on the nodev list.
 734          * A race with shutdown() or connect() would cause problems
 735          * (since rds_iwdev would change) but that should never happen.
 736          */
 737         lock_ptr = ic->rds_iwdev ? &ic->rds_iwdev->spinlock : &iw_nodev_conns_lock;
 738
 739         spin_lock_irq(lock_ptr);
 740         list_del(&ic->iw_node);
 741         spin_unlock_irq(lock_ptr);
 742
 743         kfree(ic);
 744 }
 745
 746 /*
 747  * An error occurred on the connection
 748  */
 749 void
 750 __rds_iw_conn_error(struct rds_connection *conn, const char *fmt, ...)
 751 {
 752         va_list ap;
 753
 754         rds_conn_drop(conn);
 755
 756         va_start(ap, fmt);
 757         vprintk(fmt, ap);
 758         va_end(ap);
 759 }