drivers/infiniband/core/iwcm.c

   1 /*
   2  * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
   3  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
   4  * Copyright (c) 2004, 2005 Voltaire Corporation.  All rights reserved.
   5  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
   6  * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
   7  * Copyright (c) 2005 Network Appliance, Inc. All rights reserved.
   8  *
   9  * This software is available to you under a choice of one of two
  10  * licenses.  You may choose to be licensed under the terms of the GNU
  11  * General Public License (GPL) Version 2, available from the file
  12  * COPYING in the main directory of this source tree, or the
  13  * OpenIB.org BSD license below:
  14  *
  15  *     Redistribution and use in source and binary forms, with or
  16  *     without modification, are permitted provided that the following
  17  *     conditions are met:
  18  *
  19  *      - Redistributions of source code must retain the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer.
  22  *
  23  *      - Redistributions in binary form must reproduce the above
  24  *        copyright notice, this list of conditions and the following
  25  *        disclaimer in the documentation and/or other materials
  26  *        provided with the distribution.
  27  *
  28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  29  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  30  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  31  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  32  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  33  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  34  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  35  * SOFTWARE.
  36  *
  37  */
  38 #include <linux/dma-mapping.h>
  39 #include <linux/err.h>
  40 #include <linux/idr.h>
  41 #include <linux/interrupt.h>
  42 #include <linux/rbtree.h>
  43 #include <linux/sched.h>
  44 #include <linux/spinlock.h>
  45 #include <linux/workqueue.h>
  46 #include <linux/completion.h>
  47 #include <linux/slab.h>
  48 #include <linux/module.h>
  49 #include <linux/sysctl.h>
  50
  51 #include <rdma/iw_cm.h>
  52 #include <rdma/ib_addr.h>
  53 #include <rdma/iw_portmap.h>
  54 #include <rdma/rdma_netlink.h>
  55
  56 #include "iwcm.h"
  57
  58 MODULE_AUTHOR("Tom Tucker");
  59 MODULE_DESCRIPTION("iWARP CM");
  60 MODULE_LICENSE("Dual BSD/GPL");
  61
  62 static struct ibnl_client_cbs iwcm_nl_cb_table[] = {
  63         [RDMA_NL_IWPM_REG_PID] = {.dump = iwpm_register_pid_cb},
  64         [RDMA_NL_IWPM_ADD_MAPPING] = {.dump = iwpm_add_mapping_cb},
  65         [RDMA_NL_IWPM_QUERY_MAPPING] = {.dump = iwpm_add_and_query_mapping_cb},
  66         [RDMA_NL_IWPM_REMOTE_INFO] = {.dump = iwpm_remote_info_cb},
  67         [RDMA_NL_IWPM_HANDLE_ERR] = {.dump = iwpm_mapping_error_cb},
  68         [RDMA_NL_IWPM_MAPINFO] = {.dump = iwpm_mapping_info_cb},
  69         [RDMA_NL_IWPM_MAPINFO_NUM] = {.dump = iwpm_ack_mapping_info_cb}
  70 };
  71
  72 static struct workqueue_struct *iwcm_wq;
  73 struct iwcm_work {
  74         struct work_struct work;
  75         struct iwcm_id_private *cm_id;
  76         struct list_head list;
  77         struct iw_cm_event event;
  78         struct list_head free_list;
  79 };
  80
  81 static unsigned int default_backlog = 256;
  82
  83 static struct ctl_table_header *iwcm_ctl_table_hdr;
  84 static struct ctl_table iwcm_ctl_table[] = {
  85         {
  86                 .procname       = "default_backlog",
  87                 .data           = &default_backlog,
  88                 .maxlen         = sizeof(default_backlog),
  89                 .mode           = 0644,
  90                 .proc_handler   = proc_dointvec,
  91         },
  92         { }
  93 };
  94
  95 /*
  96  * The following services provide a mechanism for pre-allocating iwcm_work
  97  * elements.  The design pre-allocates them  based on the cm_id type:
  98  *      LISTENING IDS:  Get enough elements preallocated to handle the
  99  *                      listen backlog.
 100  *      ACTIVE IDS:     4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
 101  *      PASSIVE IDS:    3: ESTABLISHED, DISCONNECT, CLOSE
 102  *
 103  * Allocating them in connect and listen avoids having to deal
 104  * with allocation failures on the event upcall from the provider (which
 105  * is called in the interrupt context).
 106  *
 107  * One exception is when creating the cm_id for incoming connection requests.
 108  * There are two cases:
 109  * 1) in the event upcall, cm_event_handler(), for a listening cm_id.  If
 110  *    the backlog is exceeded, then no more connection request events will
 111  *    be processed.  cm_event_handler() returns -ENOMEM in this case.  Its up
 112  *    to the provider to reject the connection request.
 113  * 2) in the connection request workqueue handler, cm_conn_req_handler().
 114  *    If work elements cannot be allocated for the new connect request cm_id,
 115  *    then IWCM will call the provider reject method.  This is ok since
 116  *    cm_conn_req_handler() runs in the workqueue thread context.
 117  */
 118
 119 static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
 120 {
 121         struct iwcm_work *work;
 122
 123         if (list_empty(&cm_id_priv->work_free_list))
 124                 return NULL;
 125         work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
 126                           free_list);
 127         list_del_init(&work->free_list);
 128         return work;
 129 }
 130
 131 static void put_work(struct iwcm_work *work)
 132 {
 133         list_add(&work->free_list, &work->cm_id->work_free_list);
 134 }
 135
 136 static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
 137 {
 138         struct list_head *e, *tmp;
 139
 140         list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
 141                 kfree(list_entry(e, struct iwcm_work, free_list));
 142 }
 143
 144 static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
 145 {
 146         struct iwcm_work *work;
 147
 148         BUG_ON(!list_empty(&cm_id_priv->work_free_list));
 149         while (count--) {
 150                 work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
 151                 if (!work) {
 152                         dealloc_work_entries(cm_id_priv);
 153                         return -ENOMEM;
 154                 }
 155                 work->cm_id = cm_id_priv;
 156                 INIT_LIST_HEAD(&work->list);
 157                 put_work(work);
 158         }
 159         return 0;
 160 }
 161
 162 /*
 163  * Save private data from incoming connection requests to
 164  * iw_cm_event, so the low level driver doesn't have to. Adjust
 165  * the event ptr to point to the local copy.
 166  */
 167 static int copy_private_data(struct iw_cm_event *event)
 168 {
 169         void *p;
 170
 171         p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
 172         if (!p)
 173                 return -ENOMEM;
 174         event->private_data = p;
 175         return 0;
 176 }
 177
 178 static void free_cm_id(struct iwcm_id_private *cm_id_priv)
 179 {
 180         dealloc_work_entries(cm_id_priv);
 181         kfree(cm_id_priv);
 182 }
 183
 184 /*
 185  * Release a reference on cm_id. If the last reference is being
 186  * released, free the cm_id and return 1.
 187  */
 188 static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
 189 {
 190         BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
 191         if (atomic_dec_and_test(&cm_id_priv->refcount)) {
 192                 BUG_ON(!list_empty(&cm_id_priv->work_list));
 193                 free_cm_id(cm_id_priv);
 194                 return 1;
 195         }
 196
 197         return 0;
 198 }
 199
 200 static void add_ref(struct iw_cm_id *cm_id)
 201 {
 202         struct iwcm_id_private *cm_id_priv;
 203         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 204         atomic_inc(&cm_id_priv->refcount);
 205 }
 206
 207 static void rem_ref(struct iw_cm_id *cm_id)
 208 {
 209         struct iwcm_id_private *cm_id_priv;
 210
 211         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 212
 213         (void)iwcm_deref_id(cm_id_priv);
 214 }
 215
 216 static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
 217
 218 struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
 219                                  iw_cm_handler cm_handler,
 220                                  void *context)
 221 {
 222         struct iwcm_id_private *cm_id_priv;
 223
 224         cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
 225         if (!cm_id_priv)
 226                 return ERR_PTR(-ENOMEM);
 227
 228         cm_id_priv->state = IW_CM_STATE_IDLE;
 229         cm_id_priv->id.device = device;
 230         cm_id_priv->id.cm_handler = cm_handler;
 231         cm_id_priv->id.context = context;
 232         cm_id_priv->id.event_handler = cm_event_handler;
 233         cm_id_priv->id.add_ref = add_ref;
 234         cm_id_priv->id.rem_ref = rem_ref;
 235         spin_lock_init(&cm_id_priv->lock);
 236         atomic_set(&cm_id_priv->refcount, 1);
 237         init_waitqueue_head(&cm_id_priv->connect_wait);
 238         init_completion(&cm_id_priv->destroy_comp);
 239         INIT_LIST_HEAD(&cm_id_priv->work_list);
 240         INIT_LIST_HEAD(&cm_id_priv->work_free_list);
 241
 242         return &cm_id_priv->id;
 243 }
 244 EXPORT_SYMBOL(iw_create_cm_id);
 245
 246
 247 static int iwcm_modify_qp_err(struct ib_qp *qp)
 248 {
 249         struct ib_qp_attr qp_attr;
 250
 251         if (!qp)
 252                 return -EINVAL;
 253
 254         qp_attr.qp_state = IB_QPS_ERR;
 255         return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
 256 }
 257
 258 /*
 259  * This is really the RDMAC CLOSING state. It is most similar to the
 260  * IB SQD QP state.
 261  */
 262 static int iwcm_modify_qp_sqd(struct ib_qp *qp)
 263 {
 264         struct ib_qp_attr qp_attr;
 265
 266         BUG_ON(qp == NULL);
 267         qp_attr.qp_state = IB_QPS_SQD;
 268         return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
 269 }
 270
 271 /*
 272  * CM_ID <-- CLOSING
 273  *
 274  * Block if a passive or active connection is currently being processed. Then
 275  * process the event as follows:
 276  * - If we are ESTABLISHED, move to CLOSING and modify the QP state
 277  *   based on the abrupt flag
 278  * - If the connection is already in the CLOSING or IDLE state, the peer is
 279  *   disconnecting concurrently with us and we've already seen the
 280  *   DISCONNECT event -- ignore the request and return 0
 281  * - Disconnect on a listening endpoint returns -EINVAL
 282  */
 283 int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
 284 {
 285         struct iwcm_id_private *cm_id_priv;
 286         unsigned long flags;
 287         int ret = 0;
 288         struct ib_qp *qp = NULL;
 289
 290         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 291         /* Wait if we're currently in a connect or accept downcall */
 292         wait_event(cm_id_priv->connect_wait,
 293                    !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
 294
 295         spin_lock_irqsave(&cm_id_priv->lock, flags);
 296         switch (cm_id_priv->state) {
 297         case IW_CM_STATE_ESTABLISHED:
 298                 cm_id_priv->state = IW_CM_STATE_CLOSING;
 299
 300                 /* QP could be <nul> for user-mode client */
 301                 if (cm_id_priv->qp)
 302                         qp = cm_id_priv->qp;
 303                 else
 304                         ret = -EINVAL;
 305                 break;
 306         case IW_CM_STATE_LISTEN:
 307                 ret = -EINVAL;
 308                 break;
 309         case IW_CM_STATE_CLOSING:
 310                 /* remote peer closed first */
 311         case IW_CM_STATE_IDLE:
 312                 /* accept or connect returned !0 */
 313                 break;
 314         case IW_CM_STATE_CONN_RECV:
 315                 /*
 316                  * App called disconnect before/without calling accept after
 317                  * connect_request event delivered.
 318                  */
 319                 break;
 320         case IW_CM_STATE_CONN_SENT:
 321                 /* Can only get here if wait above fails */
 322         default:
 323                 BUG();
 324         }
 325         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 326
 327         if (qp) {
 328                 if (abrupt)
 329                         ret = iwcm_modify_qp_err(qp);
 330                 else
 331                         ret = iwcm_modify_qp_sqd(qp);
 332
 333                 /*
 334                  * If both sides are disconnecting the QP could
 335                  * already be in ERR or SQD states
 336                  */
 337                 ret = 0;
 338         }
 339
 340         return ret;
 341 }
 342 EXPORT_SYMBOL(iw_cm_disconnect);
 343
 344 /*
 345  * CM_ID <-- DESTROYING
 346  *
 347  * Clean up all resources associated with the connection and release
 348  * the initial reference taken by iw_create_cm_id.
 349  */
 350 static void destroy_cm_id(struct iw_cm_id *cm_id)
 351 {
 352         struct iwcm_id_private *cm_id_priv;
 353         unsigned long flags;
 354
 355         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 356         /*
 357          * Wait if we're currently in a connect or accept downcall. A
 358          * listening endpoint should never block here.
 359          */
 360         wait_event(cm_id_priv->connect_wait,
 361                    !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
 362
 363         /*
 364          * Since we're deleting the cm_id, drop any events that
 365          * might arrive before the last dereference.
 366          */
 367         set_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags);
 368
 369         spin_lock_irqsave(&cm_id_priv->lock, flags);
 370         switch (cm_id_priv->state) {
 371         case IW_CM_STATE_LISTEN:
 372                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
 373                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 374                 /* destroy the listening endpoint */
 375                 cm_id->device->iwcm->destroy_listen(cm_id);
 376                 spin_lock_irqsave(&cm_id_priv->lock, flags);
 377                 break;
 378         case IW_CM_STATE_ESTABLISHED:
 379                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
 380                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 381                 /* Abrupt close of the connection */
 382                 (void)iwcm_modify_qp_err(cm_id_priv->qp);
 383                 spin_lock_irqsave(&cm_id_priv->lock, flags);
 384                 break;
 385         case IW_CM_STATE_IDLE:
 386         case IW_CM_STATE_CLOSING:
 387                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
 388                 break;
 389         case IW_CM_STATE_CONN_RECV:
 390                 /*
 391                  * App called destroy before/without calling accept after
 392                  * receiving connection request event notification or
 393                  * returned non zero from the event callback function.
 394                  * In either case, must tell the provider to reject.
 395                  */
 396                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
 397                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 398                 cm_id->device->iwcm->reject(cm_id, NULL, 0);
 399                 spin_lock_irqsave(&cm_id_priv->lock, flags);
 400                 break;
 401         case IW_CM_STATE_CONN_SENT:
 402         case IW_CM_STATE_DESTROYING:
 403         default:
 404                 BUG();
 405                 break;
 406         }
 407         if (cm_id_priv->qp) {
 408                 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
 409                 cm_id_priv->qp = NULL;
 410         }
 411         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 412
 413         if (cm_id->mapped) {
 414                 iwpm_remove_mapinfo(&cm_id->local_addr, &cm_id->m_local_addr);
 415                 iwpm_remove_mapping(&cm_id->local_addr, RDMA_NL_IWCM);
 416         }
 417
 418         (void)iwcm_deref_id(cm_id_priv);
 419 }
 420
 421 /*
 422  * This function is only called by the application thread and cannot
 423  * be called by the event thread. The function will wait for all
 424  * references to be released on the cm_id and then kfree the cm_id
 425  * object.
 426  */
 427 void iw_destroy_cm_id(struct iw_cm_id *cm_id)
 428 {
 429         struct iwcm_id_private *cm_id_priv;
 430
 431         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 432         destroy_cm_id(cm_id);
 433 }
 434 EXPORT_SYMBOL(iw_destroy_cm_id);
 435
 436 /**
 437  * iw_cm_check_wildcard - If IP address is 0 then use original
 438  * @pm_addr: sockaddr containing the ip to check for wildcard
 439  * @cm_addr: sockaddr containing the actual IP address
 440  * @cm_outaddr: sockaddr to set IP addr which leaving port
 441  *
 442  *  Checks the pm_addr for wildcard and then sets cm_outaddr's
 443  *  IP to the actual (cm_addr).
 444  */
 445 static void iw_cm_check_wildcard(struct sockaddr_storage *pm_addr,
 446                                  struct sockaddr_storage *cm_addr,
 447                                  struct sockaddr_storage *cm_outaddr)
 448 {
 449         if (pm_addr->ss_family == AF_INET) {
 450                 struct sockaddr_in *pm4_addr = (struct sockaddr_in *)pm_addr;
 451
 452                 if (pm4_addr->sin_addr.s_addr == htonl(INADDR_ANY)) {
 453                         struct sockaddr_in *cm4_addr =
 454                                 (struct sockaddr_in *)cm_addr;
 455                         struct sockaddr_in *cm4_outaddr =
 456                                 (struct sockaddr_in *)cm_outaddr;
 457
 458                         cm4_outaddr->sin_addr = cm4_addr->sin_addr;
 459                 }
 460         } else {
 461                 struct sockaddr_in6 *pm6_addr = (struct sockaddr_in6 *)pm_addr;
 462
 463                 if (ipv6_addr_type(&pm6_addr->sin6_addr) == IPV6_ADDR_ANY) {
 464                         struct sockaddr_in6 *cm6_addr =
 465                                 (struct sockaddr_in6 *)cm_addr;
 466                         struct sockaddr_in6 *cm6_outaddr =
 467                                 (struct sockaddr_in6 *)cm_outaddr;
 468
 469                         cm6_outaddr->sin6_addr = cm6_addr->sin6_addr;
 470                 }
 471         }
 472 }
 473
 474 /**
 475  * iw_cm_map - Use portmapper to map the ports
 476  * @cm_id: connection manager pointer
 477  * @active: Indicates the active side when true
 478  * returns nonzero for error only if iwpm_create_mapinfo() fails
 479  *
 480  * Tries to add a mapping for a port using the Portmapper. If
 481  * successful in mapping the IP/Port it will check the remote
 482  * mapped IP address for a wildcard IP address and replace the
 483  * zero IP address with the remote_addr.
 484  */
 485 static int iw_cm_map(struct iw_cm_id *cm_id, bool active)
 486 {
 487         struct iwpm_dev_data pm_reg_msg;
 488         struct iwpm_sa_data pm_msg;
 489         int status;
 490
 491         cm_id->m_local_addr = cm_id->local_addr;
 492         cm_id->m_remote_addr = cm_id->remote_addr;
 493
 494         memcpy(pm_reg_msg.dev_name, cm_id->device->name,
 495                sizeof(pm_reg_msg.dev_name));
 496         memcpy(pm_reg_msg.if_name, cm_id->device->iwcm->ifname,
 497                sizeof(pm_reg_msg.if_name));
 498
 499         if (iwpm_register_pid(&pm_reg_msg, RDMA_NL_IWCM) ||
 500             !iwpm_valid_pid())
 501                 return 0;
 502
 503         cm_id->mapped = true;
 504         pm_msg.loc_addr = cm_id->local_addr;
 505         pm_msg.rem_addr = cm_id->remote_addr;
 506         if (active)
 507                 status = iwpm_add_and_query_mapping(&pm_msg,
 508                                                     RDMA_NL_IWCM);
 509         else
 510                 status = iwpm_add_mapping(&pm_msg, RDMA_NL_IWCM);
 511
 512         if (!status) {
 513                 cm_id->m_local_addr = pm_msg.mapped_loc_addr;
 514                 if (active) {
 515                         cm_id->m_remote_addr = pm_msg.mapped_rem_addr;
 516                         iw_cm_check_wildcard(&pm_msg.mapped_rem_addr,
 517                                              &cm_id->remote_addr,
 518                                              &cm_id->m_remote_addr);
 519                 }
 520         }
 521
 522         return iwpm_create_mapinfo(&cm_id->local_addr,
 523                                    &cm_id->m_local_addr,
 524                                    RDMA_NL_IWCM);
 525 }
 526
 527 /*
 528  * CM_ID <-- LISTEN
 529  *
 530  * Start listening for connect requests. Generates one CONNECT_REQUEST
 531  * event for each inbound connect request.
 532  */
 533 int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
 534 {
 535         struct iwcm_id_private *cm_id_priv;
 536         unsigned long flags;
 537         int ret;
 538
 539         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 540
 541         if (!backlog)
 542                 backlog = default_backlog;
 543
 544         ret = alloc_work_entries(cm_id_priv, backlog);
 545         if (ret)
 546                 return ret;
 547
 548         spin_lock_irqsave(&cm_id_priv->lock, flags);
 549         switch (cm_id_priv->state) {
 550         case IW_CM_STATE_IDLE:
 551                 cm_id_priv->state = IW_CM_STATE_LISTEN;
 552                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 553                 ret = iw_cm_map(cm_id, false);
 554                 if (!ret)
 555                         ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
 556                 if (ret)
 557                         cm_id_priv->state = IW_CM_STATE_IDLE;
 558                 spin_lock_irqsave(&cm_id_priv->lock, flags);
 559                 break;
 560         default:
 561                 ret = -EINVAL;
 562         }
 563         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 564
 565         return ret;
 566 }
 567 EXPORT_SYMBOL(iw_cm_listen);
 568
 569 /*
 570  * CM_ID <-- IDLE
 571  *
 572  * Rejects an inbound connection request. No events are generated.
 573  */
 574 int iw_cm_reject(struct iw_cm_id *cm_id,
 575                  const void *private_data,
 576                  u8 private_data_len)
 577 {
 578         struct iwcm_id_private *cm_id_priv;
 579         unsigned long flags;
 580         int ret;
 581
 582         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 583         set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 584
 585         spin_lock_irqsave(&cm_id_priv->lock, flags);
 586         if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
 587                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 588                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 589                 wake_up_all(&cm_id_priv->connect_wait);
 590                 return -EINVAL;
 591         }
 592         cm_id_priv->state = IW_CM_STATE_IDLE;
 593         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 594
 595         ret = cm_id->device->iwcm->reject(cm_id, private_data,
 596                                           private_data_len);
 597
 598         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 599         wake_up_all(&cm_id_priv->connect_wait);
 600
 601         return ret;
 602 }
 603 EXPORT_SYMBOL(iw_cm_reject);
 604
 605 /*
 606  * CM_ID <-- ESTABLISHED
 607  *
 608  * Accepts an inbound connection request and generates an ESTABLISHED
 609  * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
 610  * until the ESTABLISHED event is received from the provider.
 611  */
 612 int iw_cm_accept(struct iw_cm_id *cm_id,
 613                  struct iw_cm_conn_param *iw_param)
 614 {
 615         struct iwcm_id_private *cm_id_priv;
 616         struct ib_qp *qp;
 617         unsigned long flags;
 618         int ret;
 619
 620         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 621         set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 622
 623         spin_lock_irqsave(&cm_id_priv->lock, flags);
 624         if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
 625                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 626                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 627                 wake_up_all(&cm_id_priv->connect_wait);
 628                 return -EINVAL;
 629         }
 630         /* Get the ib_qp given the QPN */
 631         qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
 632         if (!qp) {
 633                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 634                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 635                 wake_up_all(&cm_id_priv->connect_wait);
 636                 return -EINVAL;
 637         }
 638         cm_id->device->iwcm->add_ref(qp);
 639         cm_id_priv->qp = qp;
 640         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 641
 642         ret = cm_id->device->iwcm->accept(cm_id, iw_param);
 643         if (ret) {
 644                 /* An error on accept precludes provider events */
 645                 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
 646                 cm_id_priv->state = IW_CM_STATE_IDLE;
 647                 spin_lock_irqsave(&cm_id_priv->lock, flags);
 648                 if (cm_id_priv->qp) {
 649                         cm_id->device->iwcm->rem_ref(qp);
 650                         cm_id_priv->qp = NULL;
 651                 }
 652                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 653                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 654                 wake_up_all(&cm_id_priv->connect_wait);
 655         }
 656
 657         return ret;
 658 }
 659 EXPORT_SYMBOL(iw_cm_accept);
 660
 661 /*
 662  * Active Side: CM_ID <-- CONN_SENT
 663  *
 664  * If successful, results in the generation of a CONNECT_REPLY
 665  * event. iw_cm_disconnect and iw_cm_destroy will block until the
 666  * CONNECT_REPLY event is received from the provider.
 667  */
 668 int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
 669 {
 670         struct iwcm_id_private *cm_id_priv;
 671         int ret;
 672         unsigned long flags;
 673         struct ib_qp *qp;
 674
 675         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 676
 677         ret = alloc_work_entries(cm_id_priv, 4);
 678         if (ret)
 679                 return ret;
 680
 681         set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 682         spin_lock_irqsave(&cm_id_priv->lock, flags);
 683
 684         if (cm_id_priv->state != IW_CM_STATE_IDLE) {
 685                 ret = -EINVAL;
 686                 goto err;
 687         }
 688
 689         /* Get the ib_qp given the QPN */
 690         qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
 691         if (!qp) {
 692                 ret = -EINVAL;
 693                 goto err;
 694         }
 695         cm_id->device->iwcm->add_ref(qp);
 696         cm_id_priv->qp = qp;
 697         cm_id_priv->state = IW_CM_STATE_CONN_SENT;
 698         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 699
 700         ret = iw_cm_map(cm_id, true);
 701         if (!ret)
 702                 ret = cm_id->device->iwcm->connect(cm_id, iw_param);
 703         if (!ret)
 704                 return 0;       /* success */
 705
 706         spin_lock_irqsave(&cm_id_priv->lock, flags);
 707         if (cm_id_priv->qp) {
 708                 cm_id->device->iwcm->rem_ref(qp);
 709                 cm_id_priv->qp = NULL;
 710         }
 711         cm_id_priv->state = IW_CM_STATE_IDLE;
 712 err:
 713         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 714         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 715         wake_up_all(&cm_id_priv->connect_wait);
 716         return ret;
 717 }
 718 EXPORT_SYMBOL(iw_cm_connect);
 719
 720 /*
 721  * Passive Side: new CM_ID <-- CONN_RECV
 722  *
 723  * Handles an inbound connect request. The function creates a new
 724  * iw_cm_id to represent the new connection and inherits the client
 725  * callback function and other attributes from the listening parent.
 726  *
 727  * The work item contains a pointer to the listen_cm_id and the event. The
 728  * listen_cm_id contains the client cm_handler, context and
 729  * device. These are copied when the device is cloned. The event
 730  * contains the new four tuple.
 731  *
 732  * An error on the child should not affect the parent, so this
 733  * function does not return a value.
 734  */
 735 static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
 736                                 struct iw_cm_event *iw_event)
 737 {
 738         unsigned long flags;
 739         struct iw_cm_id *cm_id;
 740         struct iwcm_id_private *cm_id_priv;
 741         int ret;
 742
 743         /*
 744          * The provider should never generate a connection request
 745          * event with a bad status.
 746          */
 747         BUG_ON(iw_event->status);
 748
 749         cm_id = iw_create_cm_id(listen_id_priv->id.device,
 750                                 listen_id_priv->id.cm_handler,
 751                                 listen_id_priv->id.context);
 752         /* If the cm_id could not be created, ignore the request */
 753         if (IS_ERR(cm_id))
 754                 goto out;
 755
 756         cm_id->provider_data = iw_event->provider_data;
 757         cm_id->m_local_addr = iw_event->local_addr;
 758         cm_id->m_remote_addr = iw_event->remote_addr;
 759         cm_id->local_addr = listen_id_priv->id.local_addr;
 760
 761         ret = iwpm_get_remote_info(&listen_id_priv->id.m_local_addr,
 762                                    &iw_event->remote_addr,
 763                                    &cm_id->remote_addr,
 764                                    RDMA_NL_IWCM);
 765         if (ret) {
 766                 cm_id->remote_addr = iw_event->remote_addr;
 767         } else {
 768                 iw_cm_check_wildcard(&listen_id_priv->id.m_local_addr,
 769                                      &iw_event->local_addr,
 770                                      &cm_id->local_addr);
 771                 iw_event->local_addr = cm_id->local_addr;
 772                 iw_event->remote_addr = cm_id->remote_addr;
 773         }
 774
 775         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
 776         cm_id_priv->state = IW_CM_STATE_CONN_RECV;
 777
 778         /*
 779          * We could be destroying the listening id. If so, ignore this
 780          * upcall.
 781          */
 782         spin_lock_irqsave(&listen_id_priv->lock, flags);
 783         if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
 784                 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
 785                 iw_cm_reject(cm_id, NULL, 0);
 786                 iw_destroy_cm_id(cm_id);
 787                 goto out;
 788         }
 789         spin_unlock_irqrestore(&listen_id_priv->lock, flags);
 790
 791         ret = alloc_work_entries(cm_id_priv, 3);
 792         if (ret) {
 793                 iw_cm_reject(cm_id, NULL, 0);
 794                 iw_destroy_cm_id(cm_id);
 795                 goto out;
 796         }
 797
 798         /* Call the client CM handler */
 799         ret = cm_id->cm_handler(cm_id, iw_event);
 800         if (ret) {
 801                 iw_cm_reject(cm_id, NULL, 0);
 802                 iw_destroy_cm_id(cm_id);
 803         }
 804
 805 out:
 806         if (iw_event->private_data_len)
 807                 kfree(iw_event->private_data);
 808 }
 809
 810 /*
 811  * Passive Side: CM_ID <-- ESTABLISHED
 812  *
 813  * The provider generated an ESTABLISHED event which means that
 814  * the MPA negotion has completed successfully and we are now in MPA
 815  * FPDU mode.
 816  *
 817  * This event can only be received in the CONN_RECV state. If the
 818  * remote peer closed, the ESTABLISHED event would be received followed
 819  * by the CLOSE event. If the app closes, it will block until we wake
 820  * it up after processing this event.
 821  */
 822 static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
 823                                struct iw_cm_event *iw_event)
 824 {
 825         unsigned long flags;
 826         int ret;
 827
 828         spin_lock_irqsave(&cm_id_priv->lock, flags);
 829
 830         /*
 831          * We clear the CONNECT_WAIT bit here to allow the callback
 832          * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
 833          * from a callback handler is not allowed.
 834          */
 835         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 836         BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
 837         cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
 838         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 839         ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
 840         wake_up_all(&cm_id_priv->connect_wait);
 841
 842         return ret;
 843 }
 844
 845 /*
 846  * Active Side: CM_ID <-- ESTABLISHED
 847  *
 848  * The app has called connect and is waiting for the established event to
 849  * post it's requests to the server. This event will wake up anyone
 850  * blocked in iw_cm_disconnect or iw_destroy_id.
 851  */
 852 static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
 853                                struct iw_cm_event *iw_event)
 854 {
 855         unsigned long flags;
 856         int ret;
 857
 858         spin_lock_irqsave(&cm_id_priv->lock, flags);
 859         /*
 860          * Clear the connect wait bit so a callback function calling
 861          * iw_cm_disconnect will not wait and deadlock this thread
 862          */
 863         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
 864         BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
 865         if (iw_event->status == 0) {
 866                 cm_id_priv->id.m_local_addr = iw_event->local_addr;
 867                 cm_id_priv->id.m_remote_addr = iw_event->remote_addr;
 868                 iw_event->local_addr = cm_id_priv->id.local_addr;
 869                 iw_event->remote_addr = cm_id_priv->id.remote_addr;
 870                 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
 871         } else {
 872                 /* REJECTED or RESET */
 873                 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
 874                 cm_id_priv->qp = NULL;
 875                 cm_id_priv->state = IW_CM_STATE_IDLE;
 876         }
 877         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 878         ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
 879
 880         if (iw_event->private_data_len)
 881                 kfree(iw_event->private_data);
 882
 883         /* Wake up waiters on connect complete */
 884         wake_up_all(&cm_id_priv->connect_wait);
 885
 886         return ret;
 887 }
 888
 889 /*
 890  * CM_ID <-- CLOSING
 891  *
 892  * If in the ESTABLISHED state, move to CLOSING.
 893  */
 894 static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
 895                                   struct iw_cm_event *iw_event)
 896 {
 897         unsigned long flags;
 898
 899         spin_lock_irqsave(&cm_id_priv->lock, flags);
 900         if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
 901                 cm_id_priv->state = IW_CM_STATE_CLOSING;
 902         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 903 }
 904
 905 /*
 906  * CM_ID <-- IDLE
 907  *
 908  * If in the ESTBLISHED or CLOSING states, the QP will have have been
 909  * moved by the provider to the ERR state. Disassociate the CM_ID from
 910  * the QP,  move to IDLE, and remove the 'connected' reference.
 911  *
 912  * If in some other state, the cm_id was destroyed asynchronously.
 913  * This is the last reference that will result in waking up
 914  * the app thread blocked in iw_destroy_cm_id.
 915  */
 916 static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
 917                                   struct iw_cm_event *iw_event)
 918 {
 919         unsigned long flags;
 920         int ret = 0;
 921         spin_lock_irqsave(&cm_id_priv->lock, flags);
 922
 923         if (cm_id_priv->qp) {
 924                 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
 925                 cm_id_priv->qp = NULL;
 926         }
 927         switch (cm_id_priv->state) {
 928         case IW_CM_STATE_ESTABLISHED:
 929         case IW_CM_STATE_CLOSING:
 930                 cm_id_priv->state = IW_CM_STATE_IDLE;
 931                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 932                 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
 933                 spin_lock_irqsave(&cm_id_priv->lock, flags);
 934                 break;
 935         case IW_CM_STATE_DESTROYING:
 936                 break;
 937         default:
 938                 BUG();
 939         }
 940         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
 941
 942         return ret;
 943 }
 944
 945 static int process_event(struct iwcm_id_private *cm_id_priv,
 946                          struct iw_cm_event *iw_event)
 947 {
 948         int ret = 0;
 949
 950         switch (iw_event->event) {
 951         case IW_CM_EVENT_CONNECT_REQUEST:
 952                 cm_conn_req_handler(cm_id_priv, iw_event);
 953                 break;
 954         case IW_CM_EVENT_CONNECT_REPLY:
 955                 ret = cm_conn_rep_handler(cm_id_priv, iw_event);
 956                 break;
 957         case IW_CM_EVENT_ESTABLISHED:
 958                 ret = cm_conn_est_handler(cm_id_priv, iw_event);
 959                 break;
 960         case IW_CM_EVENT_DISCONNECT:
 961                 cm_disconnect_handler(cm_id_priv, iw_event);
 962                 break;
 963         case IW_CM_EVENT_CLOSE:
 964                 ret = cm_close_handler(cm_id_priv, iw_event);
 965                 break;
 966         default:
 967                 BUG();
 968         }
 969
 970         return ret;
 971 }
 972
 973 /*
 974  * Process events on the work_list for the cm_id. If the callback
 975  * function requests that the cm_id be deleted, a flag is set in the
 976  * cm_id flags to indicate that when the last reference is
 977  * removed, the cm_id is to be destroyed. This is necessary to
 978  * distinguish between an object that will be destroyed by the app
 979  * thread asleep on the destroy_comp list vs. an object destroyed
 980  * here synchronously when the last reference is removed.
 981  */
 982 static void cm_work_handler(struct work_struct *_work)
 983 {
 984         struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
 985         struct iw_cm_event levent;
 986         struct iwcm_id_private *cm_id_priv = work->cm_id;
 987         unsigned long flags;
 988         int empty;
 989         int ret = 0;
 990
 991         spin_lock_irqsave(&cm_id_priv->lock, flags);
 992         empty = list_empty(&cm_id_priv->work_list);
 993         while (!empty) {
 994                 work = list_entry(cm_id_priv->work_list.next,
 995                                   struct iwcm_work, list);
 996                 list_del_init(&work->list);
 997                 empty = list_empty(&cm_id_priv->work_list);
 998                 levent = work->event;
 999                 put_work(work);
1000                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1001
1002                 if (!test_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags)) {
1003                         ret = process_event(cm_id_priv, &levent);
1004                         if (ret)
1005                                 destroy_cm_id(&cm_id_priv->id);
1006                 } else
1007                         pr_debug("dropping event %d\n", levent.event);
1008                 if (iwcm_deref_id(cm_id_priv))
1009                         return;
1010                 if (empty)
1011                         return;
1012                 spin_lock_irqsave(&cm_id_priv->lock, flags);
1013         }
1014         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1015 }
1016
1017 /*
1018  * This function is called on interrupt context. Schedule events on
1019  * the iwcm_wq thread to allow callback functions to downcall into
1020  * the CM and/or block.  Events are queued to a per-CM_ID
1021  * work_list. If this is the first event on the work_list, the work
1022  * element is also queued on the iwcm_wq thread.
1023  *
1024  * Each event holds a reference on the cm_id. Until the last posted
1025  * event has been delivered and processed, the cm_id cannot be
1026  * deleted.
1027  *
1028  * Returns:
1029  *            0 - the event was handled.
1030  *      -ENOMEM - the event was not handled due to lack of resources.
1031  */
1032 static int cm_event_handler(struct iw_cm_id *cm_id,
1033                              struct iw_cm_event *iw_event)
1034 {
1035         struct iwcm_work *work;
1036         struct iwcm_id_private *cm_id_priv;
1037         unsigned long flags;
1038         int ret = 0;
1039
1040         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1041
1042         spin_lock_irqsave(&cm_id_priv->lock, flags);
1043         work = get_work(cm_id_priv);
1044         if (!work) {
1045                 ret = -ENOMEM;
1046                 goto out;
1047         }
1048
1049         INIT_WORK(&work->work, cm_work_handler);
1050         work->cm_id = cm_id_priv;
1051         work->event = *iw_event;
1052
1053         if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
1054              work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
1055             work->event.private_data_len) {
1056                 ret = copy_private_data(&work->event);
1057                 if (ret) {
1058                         put_work(work);
1059                         goto out;
1060                 }
1061         }
1062
1063         atomic_inc(&cm_id_priv->refcount);
1064         if (list_empty(&cm_id_priv->work_list)) {
1065                 list_add_tail(&work->list, &cm_id_priv->work_list);
1066                 queue_work(iwcm_wq, &work->work);
1067         } else
1068                 list_add_tail(&work->list, &cm_id_priv->work_list);
1069 out:
1070         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1071         return ret;
1072 }
1073
1074 static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
1075                                   struct ib_qp_attr *qp_attr,
1076                                   int *qp_attr_mask)
1077 {
1078         unsigned long flags;
1079         int ret;
1080
1081         spin_lock_irqsave(&cm_id_priv->lock, flags);
1082         switch (cm_id_priv->state) {
1083         case IW_CM_STATE_IDLE:
1084         case IW_CM_STATE_CONN_SENT:
1085         case IW_CM_STATE_CONN_RECV:
1086         case IW_CM_STATE_ESTABLISHED:
1087                 *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
1088                 qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
1089                                            IB_ACCESS_REMOTE_READ;
1090                 ret = 0;
1091                 break;
1092         default:
1093                 ret = -EINVAL;
1094                 break;
1095         }
1096         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1097         return ret;
1098 }
1099
1100 static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
1101                                   struct ib_qp_attr *qp_attr,
1102                                   int *qp_attr_mask)
1103 {
1104         unsigned long flags;
1105         int ret;
1106
1107         spin_lock_irqsave(&cm_id_priv->lock, flags);
1108         switch (cm_id_priv->state) {
1109         case IW_CM_STATE_IDLE:
1110         case IW_CM_STATE_CONN_SENT:
1111         case IW_CM_STATE_CONN_RECV:
1112         case IW_CM_STATE_ESTABLISHED:
1113                 *qp_attr_mask = 0;
1114                 ret = 0;
1115                 break;
1116         default:
1117                 ret = -EINVAL;
1118                 break;
1119         }
1120         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1121         return ret;
1122 }
1123
1124 int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
1125                        struct ib_qp_attr *qp_attr,
1126                        int *qp_attr_mask)
1127 {
1128         struct iwcm_id_private *cm_id_priv;
1129         int ret;
1130
1131         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1132         switch (qp_attr->qp_state) {
1133         case IB_QPS_INIT:
1134         case IB_QPS_RTR:
1135                 ret = iwcm_init_qp_init_attr(cm_id_priv,
1136                                              qp_attr, qp_attr_mask);
1137                 break;
1138         case IB_QPS_RTS:
1139                 ret = iwcm_init_qp_rts_attr(cm_id_priv,
1140                                             qp_attr, qp_attr_mask);
1141                 break;
1142         default:
1143                 ret = -EINVAL;
1144                 break;
1145         }
1146         return ret;
1147 }
1148 EXPORT_SYMBOL(iw_cm_init_qp_attr);
1149
1150 static int __init iw_cm_init(void)
1151 {
1152         int ret;
1153
1154         ret = iwpm_init(RDMA_NL_IWCM);
1155         if (ret)
1156                 pr_err("iw_cm: couldn't init iwpm\n");
1157
1158         ret = ibnl_add_client(RDMA_NL_IWCM, ARRAY_SIZE(iwcm_nl_cb_table),
1159                               iwcm_nl_cb_table);
1160         if (ret)
1161                 pr_err("iw_cm: couldn't register netlink callbacks\n");
1162
1163         iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
1164         if (!iwcm_wq)
1165                 return -ENOMEM;
1166
1167         iwcm_ctl_table_hdr = register_net_sysctl(&init_net, "net/iw_cm",
1168                                                  iwcm_ctl_table);
1169         if (!iwcm_ctl_table_hdr) {
1170                 pr_err("iw_cm: couldn't register sysctl paths\n");
1171                 destroy_workqueue(iwcm_wq);
1172                 return -ENOMEM;
1173         }
1174
1175         return 0;
1176 }
1177
1178 static void __exit iw_cm_cleanup(void)
1179 {
1180         unregister_net_sysctl_table(iwcm_ctl_table_hdr);
1181         destroy_workqueue(iwcm_wq);
1182         ibnl_remove_client(RDMA_NL_IWCM);
1183         iwpm_exit(RDMA_NL_IWCM);
1184 }
1185
1186 module_init(iw_cm_init);
1187 module_exit(iw_cm_cleanup);