xref: /openbmc/linux/drivers/infiniband/core/iwcm.c (revision 0edbfea5)
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, enable the waiting thread (in iw_destroy_cm_id) to
187  * get woken up, and return 1 if a thread is already waiting.
188  */
189 static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
190 {
191 	BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
192 	if (atomic_dec_and_test(&cm_id_priv->refcount)) {
193 		BUG_ON(!list_empty(&cm_id_priv->work_list));
194 		complete(&cm_id_priv->destroy_comp);
195 		return 1;
196 	}
197 
198 	return 0;
199 }
200 
201 static void add_ref(struct iw_cm_id *cm_id)
202 {
203 	struct iwcm_id_private *cm_id_priv;
204 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
205 	atomic_inc(&cm_id_priv->refcount);
206 }
207 
208 static void rem_ref(struct iw_cm_id *cm_id)
209 {
210 	struct iwcm_id_private *cm_id_priv;
211 	int cb_destroy;
212 
213 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
214 
215 	/*
216 	 * Test bit before deref in case the cm_id gets freed on another
217 	 * thread.
218 	 */
219 	cb_destroy = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
220 	if (iwcm_deref_id(cm_id_priv) && cb_destroy) {
221 		BUG_ON(!list_empty(&cm_id_priv->work_list));
222 		free_cm_id(cm_id_priv);
223 	}
224 }
225 
226 static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
227 
228 struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
229 				 iw_cm_handler cm_handler,
230 				 void *context)
231 {
232 	struct iwcm_id_private *cm_id_priv;
233 
234 	cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
235 	if (!cm_id_priv)
236 		return ERR_PTR(-ENOMEM);
237 
238 	cm_id_priv->state = IW_CM_STATE_IDLE;
239 	cm_id_priv->id.device = device;
240 	cm_id_priv->id.cm_handler = cm_handler;
241 	cm_id_priv->id.context = context;
242 	cm_id_priv->id.event_handler = cm_event_handler;
243 	cm_id_priv->id.add_ref = add_ref;
244 	cm_id_priv->id.rem_ref = rem_ref;
245 	spin_lock_init(&cm_id_priv->lock);
246 	atomic_set(&cm_id_priv->refcount, 1);
247 	init_waitqueue_head(&cm_id_priv->connect_wait);
248 	init_completion(&cm_id_priv->destroy_comp);
249 	INIT_LIST_HEAD(&cm_id_priv->work_list);
250 	INIT_LIST_HEAD(&cm_id_priv->work_free_list);
251 
252 	return &cm_id_priv->id;
253 }
254 EXPORT_SYMBOL(iw_create_cm_id);
255 
256 
257 static int iwcm_modify_qp_err(struct ib_qp *qp)
258 {
259 	struct ib_qp_attr qp_attr;
260 
261 	if (!qp)
262 		return -EINVAL;
263 
264 	qp_attr.qp_state = IB_QPS_ERR;
265 	return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
266 }
267 
268 /*
269  * This is really the RDMAC CLOSING state. It is most similar to the
270  * IB SQD QP state.
271  */
272 static int iwcm_modify_qp_sqd(struct ib_qp *qp)
273 {
274 	struct ib_qp_attr qp_attr;
275 
276 	BUG_ON(qp == NULL);
277 	qp_attr.qp_state = IB_QPS_SQD;
278 	return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
279 }
280 
281 /*
282  * CM_ID <-- CLOSING
283  *
284  * Block if a passive or active connection is currently being processed. Then
285  * process the event as follows:
286  * - If we are ESTABLISHED, move to CLOSING and modify the QP state
287  *   based on the abrupt flag
288  * - If the connection is already in the CLOSING or IDLE state, the peer is
289  *   disconnecting concurrently with us and we've already seen the
290  *   DISCONNECT event -- ignore the request and return 0
291  * - Disconnect on a listening endpoint returns -EINVAL
292  */
293 int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
294 {
295 	struct iwcm_id_private *cm_id_priv;
296 	unsigned long flags;
297 	int ret = 0;
298 	struct ib_qp *qp = NULL;
299 
300 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
301 	/* Wait if we're currently in a connect or accept downcall */
302 	wait_event(cm_id_priv->connect_wait,
303 		   !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
304 
305 	spin_lock_irqsave(&cm_id_priv->lock, flags);
306 	switch (cm_id_priv->state) {
307 	case IW_CM_STATE_ESTABLISHED:
308 		cm_id_priv->state = IW_CM_STATE_CLOSING;
309 
310 		/* QP could be <nul> for user-mode client */
311 		if (cm_id_priv->qp)
312 			qp = cm_id_priv->qp;
313 		else
314 			ret = -EINVAL;
315 		break;
316 	case IW_CM_STATE_LISTEN:
317 		ret = -EINVAL;
318 		break;
319 	case IW_CM_STATE_CLOSING:
320 		/* remote peer closed first */
321 	case IW_CM_STATE_IDLE:
322 		/* accept or connect returned !0 */
323 		break;
324 	case IW_CM_STATE_CONN_RECV:
325 		/*
326 		 * App called disconnect before/without calling accept after
327 		 * connect_request event delivered.
328 		 */
329 		break;
330 	case IW_CM_STATE_CONN_SENT:
331 		/* Can only get here if wait above fails */
332 	default:
333 		BUG();
334 	}
335 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
336 
337 	if (qp) {
338 		if (abrupt)
339 			ret = iwcm_modify_qp_err(qp);
340 		else
341 			ret = iwcm_modify_qp_sqd(qp);
342 
343 		/*
344 		 * If both sides are disconnecting the QP could
345 		 * already be in ERR or SQD states
346 		 */
347 		ret = 0;
348 	}
349 
350 	return ret;
351 }
352 EXPORT_SYMBOL(iw_cm_disconnect);
353 
354 /*
355  * CM_ID <-- DESTROYING
356  *
357  * Clean up all resources associated with the connection and release
358  * the initial reference taken by iw_create_cm_id.
359  */
360 static void destroy_cm_id(struct iw_cm_id *cm_id)
361 {
362 	struct iwcm_id_private *cm_id_priv;
363 	unsigned long flags;
364 
365 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
366 	/*
367 	 * Wait if we're currently in a connect or accept downcall. A
368 	 * listening endpoint should never block here.
369 	 */
370 	wait_event(cm_id_priv->connect_wait,
371 		   !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
372 
373 	spin_lock_irqsave(&cm_id_priv->lock, flags);
374 	switch (cm_id_priv->state) {
375 	case IW_CM_STATE_LISTEN:
376 		cm_id_priv->state = IW_CM_STATE_DESTROYING;
377 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
378 		/* destroy the listening endpoint */
379 		cm_id->device->iwcm->destroy_listen(cm_id);
380 		spin_lock_irqsave(&cm_id_priv->lock, flags);
381 		break;
382 	case IW_CM_STATE_ESTABLISHED:
383 		cm_id_priv->state = IW_CM_STATE_DESTROYING;
384 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
385 		/* Abrupt close of the connection */
386 		(void)iwcm_modify_qp_err(cm_id_priv->qp);
387 		spin_lock_irqsave(&cm_id_priv->lock, flags);
388 		break;
389 	case IW_CM_STATE_IDLE:
390 	case IW_CM_STATE_CLOSING:
391 		cm_id_priv->state = IW_CM_STATE_DESTROYING;
392 		break;
393 	case IW_CM_STATE_CONN_RECV:
394 		/*
395 		 * App called destroy before/without calling accept after
396 		 * receiving connection request event notification or
397 		 * returned non zero from the event callback function.
398 		 * In either case, must tell the provider to reject.
399 		 */
400 		cm_id_priv->state = IW_CM_STATE_DESTROYING;
401 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
402 		cm_id->device->iwcm->reject(cm_id, NULL, 0);
403 		spin_lock_irqsave(&cm_id_priv->lock, flags);
404 		break;
405 	case IW_CM_STATE_CONN_SENT:
406 	case IW_CM_STATE_DESTROYING:
407 	default:
408 		BUG();
409 		break;
410 	}
411 	if (cm_id_priv->qp) {
412 		cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
413 		cm_id_priv->qp = NULL;
414 	}
415 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
416 
417 	if (cm_id->mapped) {
418 		iwpm_remove_mapinfo(&cm_id->local_addr, &cm_id->m_local_addr);
419 		iwpm_remove_mapping(&cm_id->local_addr, RDMA_NL_IWCM);
420 	}
421 
422 	(void)iwcm_deref_id(cm_id_priv);
423 }
424 
425 /*
426  * This function is only called by the application thread and cannot
427  * be called by the event thread. The function will wait for all
428  * references to be released on the cm_id and then kfree the cm_id
429  * object.
430  */
431 void iw_destroy_cm_id(struct iw_cm_id *cm_id)
432 {
433 	struct iwcm_id_private *cm_id_priv;
434 
435 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
436 	BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags));
437 
438 	destroy_cm_id(cm_id);
439 
440 	wait_for_completion(&cm_id_priv->destroy_comp);
441 
442 	free_cm_id(cm_id_priv);
443 }
444 EXPORT_SYMBOL(iw_destroy_cm_id);
445 
446 /**
447  * iw_cm_check_wildcard - If IP address is 0 then use original
448  * @pm_addr: sockaddr containing the ip to check for wildcard
449  * @cm_addr: sockaddr containing the actual IP address
450  * @cm_outaddr: sockaddr to set IP addr which leaving port
451  *
452  *  Checks the pm_addr for wildcard and then sets cm_outaddr's
453  *  IP to the actual (cm_addr).
454  */
455 static void iw_cm_check_wildcard(struct sockaddr_storage *pm_addr,
456 				 struct sockaddr_storage *cm_addr,
457 				 struct sockaddr_storage *cm_outaddr)
458 {
459 	if (pm_addr->ss_family == AF_INET) {
460 		struct sockaddr_in *pm4_addr = (struct sockaddr_in *)pm_addr;
461 
462 		if (pm4_addr->sin_addr.s_addr == htonl(INADDR_ANY)) {
463 			struct sockaddr_in *cm4_addr =
464 				(struct sockaddr_in *)cm_addr;
465 			struct sockaddr_in *cm4_outaddr =
466 				(struct sockaddr_in *)cm_outaddr;
467 
468 			cm4_outaddr->sin_addr = cm4_addr->sin_addr;
469 		}
470 	} else {
471 		struct sockaddr_in6 *pm6_addr = (struct sockaddr_in6 *)pm_addr;
472 
473 		if (ipv6_addr_type(&pm6_addr->sin6_addr) == IPV6_ADDR_ANY) {
474 			struct sockaddr_in6 *cm6_addr =
475 				(struct sockaddr_in6 *)cm_addr;
476 			struct sockaddr_in6 *cm6_outaddr =
477 				(struct sockaddr_in6 *)cm_outaddr;
478 
479 			cm6_outaddr->sin6_addr = cm6_addr->sin6_addr;
480 		}
481 	}
482 }
483 
484 /**
485  * iw_cm_map - Use portmapper to map the ports
486  * @cm_id: connection manager pointer
487  * @active: Indicates the active side when true
488  * returns nonzero for error only if iwpm_create_mapinfo() fails
489  *
490  * Tries to add a mapping for a port using the Portmapper. If
491  * successful in mapping the IP/Port it will check the remote
492  * mapped IP address for a wildcard IP address and replace the
493  * zero IP address with the remote_addr.
494  */
495 static int iw_cm_map(struct iw_cm_id *cm_id, bool active)
496 {
497 	struct iwpm_dev_data pm_reg_msg;
498 	struct iwpm_sa_data pm_msg;
499 	int status;
500 
501 	cm_id->m_local_addr = cm_id->local_addr;
502 	cm_id->m_remote_addr = cm_id->remote_addr;
503 
504 	memcpy(pm_reg_msg.dev_name, cm_id->device->name,
505 	       sizeof(pm_reg_msg.dev_name));
506 	memcpy(pm_reg_msg.if_name, cm_id->device->iwcm->ifname,
507 	       sizeof(pm_reg_msg.if_name));
508 
509 	if (iwpm_register_pid(&pm_reg_msg, RDMA_NL_IWCM) ||
510 	    !iwpm_valid_pid())
511 		return 0;
512 
513 	cm_id->mapped = true;
514 	pm_msg.loc_addr = cm_id->local_addr;
515 	pm_msg.rem_addr = cm_id->remote_addr;
516 	if (active)
517 		status = iwpm_add_and_query_mapping(&pm_msg,
518 						    RDMA_NL_IWCM);
519 	else
520 		status = iwpm_add_mapping(&pm_msg, RDMA_NL_IWCM);
521 
522 	if (!status) {
523 		cm_id->m_local_addr = pm_msg.mapped_loc_addr;
524 		if (active) {
525 			cm_id->m_remote_addr = pm_msg.mapped_rem_addr;
526 			iw_cm_check_wildcard(&pm_msg.mapped_rem_addr,
527 					     &cm_id->remote_addr,
528 					     &cm_id->m_remote_addr);
529 		}
530 	}
531 
532 	return iwpm_create_mapinfo(&cm_id->local_addr,
533 				   &cm_id->m_local_addr,
534 				   RDMA_NL_IWCM);
535 }
536 
537 /*
538  * CM_ID <-- LISTEN
539  *
540  * Start listening for connect requests. Generates one CONNECT_REQUEST
541  * event for each inbound connect request.
542  */
543 int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
544 {
545 	struct iwcm_id_private *cm_id_priv;
546 	unsigned long flags;
547 	int ret;
548 
549 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
550 
551 	if (!backlog)
552 		backlog = default_backlog;
553 
554 	ret = alloc_work_entries(cm_id_priv, backlog);
555 	if (ret)
556 		return ret;
557 
558 	spin_lock_irqsave(&cm_id_priv->lock, flags);
559 	switch (cm_id_priv->state) {
560 	case IW_CM_STATE_IDLE:
561 		cm_id_priv->state = IW_CM_STATE_LISTEN;
562 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
563 		ret = iw_cm_map(cm_id, false);
564 		if (!ret)
565 			ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
566 		if (ret)
567 			cm_id_priv->state = IW_CM_STATE_IDLE;
568 		spin_lock_irqsave(&cm_id_priv->lock, flags);
569 		break;
570 	default:
571 		ret = -EINVAL;
572 	}
573 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
574 
575 	return ret;
576 }
577 EXPORT_SYMBOL(iw_cm_listen);
578 
579 /*
580  * CM_ID <-- IDLE
581  *
582  * Rejects an inbound connection request. No events are generated.
583  */
584 int iw_cm_reject(struct iw_cm_id *cm_id,
585 		 const void *private_data,
586 		 u8 private_data_len)
587 {
588 	struct iwcm_id_private *cm_id_priv;
589 	unsigned long flags;
590 	int ret;
591 
592 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
593 	set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
594 
595 	spin_lock_irqsave(&cm_id_priv->lock, flags);
596 	if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
597 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
598 		clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
599 		wake_up_all(&cm_id_priv->connect_wait);
600 		return -EINVAL;
601 	}
602 	cm_id_priv->state = IW_CM_STATE_IDLE;
603 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
604 
605 	ret = cm_id->device->iwcm->reject(cm_id, private_data,
606 					  private_data_len);
607 
608 	clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
609 	wake_up_all(&cm_id_priv->connect_wait);
610 
611 	return ret;
612 }
613 EXPORT_SYMBOL(iw_cm_reject);
614 
615 /*
616  * CM_ID <-- ESTABLISHED
617  *
618  * Accepts an inbound connection request and generates an ESTABLISHED
619  * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
620  * until the ESTABLISHED event is received from the provider.
621  */
622 int iw_cm_accept(struct iw_cm_id *cm_id,
623 		 struct iw_cm_conn_param *iw_param)
624 {
625 	struct iwcm_id_private *cm_id_priv;
626 	struct ib_qp *qp;
627 	unsigned long flags;
628 	int ret;
629 
630 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
631 	set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
632 
633 	spin_lock_irqsave(&cm_id_priv->lock, flags);
634 	if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
635 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
636 		clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
637 		wake_up_all(&cm_id_priv->connect_wait);
638 		return -EINVAL;
639 	}
640 	/* Get the ib_qp given the QPN */
641 	qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
642 	if (!qp) {
643 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
644 		clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
645 		wake_up_all(&cm_id_priv->connect_wait);
646 		return -EINVAL;
647 	}
648 	cm_id->device->iwcm->add_ref(qp);
649 	cm_id_priv->qp = qp;
650 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
651 
652 	ret = cm_id->device->iwcm->accept(cm_id, iw_param);
653 	if (ret) {
654 		/* An error on accept precludes provider events */
655 		BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
656 		cm_id_priv->state = IW_CM_STATE_IDLE;
657 		spin_lock_irqsave(&cm_id_priv->lock, flags);
658 		if (cm_id_priv->qp) {
659 			cm_id->device->iwcm->rem_ref(qp);
660 			cm_id_priv->qp = NULL;
661 		}
662 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
663 		clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
664 		wake_up_all(&cm_id_priv->connect_wait);
665 	}
666 
667 	return ret;
668 }
669 EXPORT_SYMBOL(iw_cm_accept);
670 
671 /*
672  * Active Side: CM_ID <-- CONN_SENT
673  *
674  * If successful, results in the generation of a CONNECT_REPLY
675  * event. iw_cm_disconnect and iw_cm_destroy will block until the
676  * CONNECT_REPLY event is received from the provider.
677  */
678 int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
679 {
680 	struct iwcm_id_private *cm_id_priv;
681 	int ret;
682 	unsigned long flags;
683 	struct ib_qp *qp;
684 
685 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
686 
687 	ret = alloc_work_entries(cm_id_priv, 4);
688 	if (ret)
689 		return ret;
690 
691 	set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
692 	spin_lock_irqsave(&cm_id_priv->lock, flags);
693 
694 	if (cm_id_priv->state != IW_CM_STATE_IDLE) {
695 		ret = -EINVAL;
696 		goto err;
697 	}
698 
699 	/* Get the ib_qp given the QPN */
700 	qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
701 	if (!qp) {
702 		ret = -EINVAL;
703 		goto err;
704 	}
705 	cm_id->device->iwcm->add_ref(qp);
706 	cm_id_priv->qp = qp;
707 	cm_id_priv->state = IW_CM_STATE_CONN_SENT;
708 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
709 
710 	ret = iw_cm_map(cm_id, true);
711 	if (!ret)
712 		ret = cm_id->device->iwcm->connect(cm_id, iw_param);
713 	if (!ret)
714 		return 0;	/* success */
715 
716 	spin_lock_irqsave(&cm_id_priv->lock, flags);
717 	if (cm_id_priv->qp) {
718 		cm_id->device->iwcm->rem_ref(qp);
719 		cm_id_priv->qp = NULL;
720 	}
721 	cm_id_priv->state = IW_CM_STATE_IDLE;
722 err:
723 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
724 	clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
725 	wake_up_all(&cm_id_priv->connect_wait);
726 	return ret;
727 }
728 EXPORT_SYMBOL(iw_cm_connect);
729 
730 /*
731  * Passive Side: new CM_ID <-- CONN_RECV
732  *
733  * Handles an inbound connect request. The function creates a new
734  * iw_cm_id to represent the new connection and inherits the client
735  * callback function and other attributes from the listening parent.
736  *
737  * The work item contains a pointer to the listen_cm_id and the event. The
738  * listen_cm_id contains the client cm_handler, context and
739  * device. These are copied when the device is cloned. The event
740  * contains the new four tuple.
741  *
742  * An error on the child should not affect the parent, so this
743  * function does not return a value.
744  */
745 static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
746 				struct iw_cm_event *iw_event)
747 {
748 	unsigned long flags;
749 	struct iw_cm_id *cm_id;
750 	struct iwcm_id_private *cm_id_priv;
751 	int ret;
752 
753 	/*
754 	 * The provider should never generate a connection request
755 	 * event with a bad status.
756 	 */
757 	BUG_ON(iw_event->status);
758 
759 	cm_id = iw_create_cm_id(listen_id_priv->id.device,
760 				listen_id_priv->id.cm_handler,
761 				listen_id_priv->id.context);
762 	/* If the cm_id could not be created, ignore the request */
763 	if (IS_ERR(cm_id))
764 		goto out;
765 
766 	cm_id->provider_data = iw_event->provider_data;
767 	cm_id->m_local_addr = iw_event->local_addr;
768 	cm_id->m_remote_addr = iw_event->remote_addr;
769 	cm_id->local_addr = listen_id_priv->id.local_addr;
770 
771 	ret = iwpm_get_remote_info(&listen_id_priv->id.m_local_addr,
772 				   &iw_event->remote_addr,
773 				   &cm_id->remote_addr,
774 				   RDMA_NL_IWCM);
775 	if (ret) {
776 		cm_id->remote_addr = iw_event->remote_addr;
777 	} else {
778 		iw_cm_check_wildcard(&listen_id_priv->id.m_local_addr,
779 				     &iw_event->local_addr,
780 				     &cm_id->local_addr);
781 		iw_event->local_addr = cm_id->local_addr;
782 		iw_event->remote_addr = cm_id->remote_addr;
783 	}
784 
785 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
786 	cm_id_priv->state = IW_CM_STATE_CONN_RECV;
787 
788 	/*
789 	 * We could be destroying the listening id. If so, ignore this
790 	 * upcall.
791 	 */
792 	spin_lock_irqsave(&listen_id_priv->lock, flags);
793 	if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
794 		spin_unlock_irqrestore(&listen_id_priv->lock, flags);
795 		iw_cm_reject(cm_id, NULL, 0);
796 		iw_destroy_cm_id(cm_id);
797 		goto out;
798 	}
799 	spin_unlock_irqrestore(&listen_id_priv->lock, flags);
800 
801 	ret = alloc_work_entries(cm_id_priv, 3);
802 	if (ret) {
803 		iw_cm_reject(cm_id, NULL, 0);
804 		iw_destroy_cm_id(cm_id);
805 		goto out;
806 	}
807 
808 	/* Call the client CM handler */
809 	ret = cm_id->cm_handler(cm_id, iw_event);
810 	if (ret) {
811 		iw_cm_reject(cm_id, NULL, 0);
812 		set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
813 		destroy_cm_id(cm_id);
814 		if (atomic_read(&cm_id_priv->refcount)==0)
815 			free_cm_id(cm_id_priv);
816 	}
817 
818 out:
819 	if (iw_event->private_data_len)
820 		kfree(iw_event->private_data);
821 }
822 
823 /*
824  * Passive Side: CM_ID <-- ESTABLISHED
825  *
826  * The provider generated an ESTABLISHED event which means that
827  * the MPA negotion has completed successfully and we are now in MPA
828  * FPDU mode.
829  *
830  * This event can only be received in the CONN_RECV state. If the
831  * remote peer closed, the ESTABLISHED event would be received followed
832  * by the CLOSE event. If the app closes, it will block until we wake
833  * it up after processing this event.
834  */
835 static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
836 			       struct iw_cm_event *iw_event)
837 {
838 	unsigned long flags;
839 	int ret;
840 
841 	spin_lock_irqsave(&cm_id_priv->lock, flags);
842 
843 	/*
844 	 * We clear the CONNECT_WAIT bit here to allow the callback
845 	 * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
846 	 * from a callback handler is not allowed.
847 	 */
848 	clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
849 	BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
850 	cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
851 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
852 	ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
853 	wake_up_all(&cm_id_priv->connect_wait);
854 
855 	return ret;
856 }
857 
858 /*
859  * Active Side: CM_ID <-- ESTABLISHED
860  *
861  * The app has called connect and is waiting for the established event to
862  * post it's requests to the server. This event will wake up anyone
863  * blocked in iw_cm_disconnect or iw_destroy_id.
864  */
865 static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
866 			       struct iw_cm_event *iw_event)
867 {
868 	unsigned long flags;
869 	int ret;
870 
871 	spin_lock_irqsave(&cm_id_priv->lock, flags);
872 	/*
873 	 * Clear the connect wait bit so a callback function calling
874 	 * iw_cm_disconnect will not wait and deadlock this thread
875 	 */
876 	clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
877 	BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
878 	if (iw_event->status == 0) {
879 		cm_id_priv->id.m_local_addr = iw_event->local_addr;
880 		cm_id_priv->id.m_remote_addr = iw_event->remote_addr;
881 		iw_event->local_addr = cm_id_priv->id.local_addr;
882 		iw_event->remote_addr = cm_id_priv->id.remote_addr;
883 		cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
884 	} else {
885 		/* REJECTED or RESET */
886 		cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
887 		cm_id_priv->qp = NULL;
888 		cm_id_priv->state = IW_CM_STATE_IDLE;
889 	}
890 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
891 	ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
892 
893 	if (iw_event->private_data_len)
894 		kfree(iw_event->private_data);
895 
896 	/* Wake up waiters on connect complete */
897 	wake_up_all(&cm_id_priv->connect_wait);
898 
899 	return ret;
900 }
901 
902 /*
903  * CM_ID <-- CLOSING
904  *
905  * If in the ESTABLISHED state, move to CLOSING.
906  */
907 static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
908 				  struct iw_cm_event *iw_event)
909 {
910 	unsigned long flags;
911 
912 	spin_lock_irqsave(&cm_id_priv->lock, flags);
913 	if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
914 		cm_id_priv->state = IW_CM_STATE_CLOSING;
915 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
916 }
917 
918 /*
919  * CM_ID <-- IDLE
920  *
921  * If in the ESTBLISHED or CLOSING states, the QP will have have been
922  * moved by the provider to the ERR state. Disassociate the CM_ID from
923  * the QP,  move to IDLE, and remove the 'connected' reference.
924  *
925  * If in some other state, the cm_id was destroyed asynchronously.
926  * This is the last reference that will result in waking up
927  * the app thread blocked in iw_destroy_cm_id.
928  */
929 static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
930 				  struct iw_cm_event *iw_event)
931 {
932 	unsigned long flags;
933 	int ret = 0;
934 	spin_lock_irqsave(&cm_id_priv->lock, flags);
935 
936 	if (cm_id_priv->qp) {
937 		cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
938 		cm_id_priv->qp = NULL;
939 	}
940 	switch (cm_id_priv->state) {
941 	case IW_CM_STATE_ESTABLISHED:
942 	case IW_CM_STATE_CLOSING:
943 		cm_id_priv->state = IW_CM_STATE_IDLE;
944 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
945 		ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
946 		spin_lock_irqsave(&cm_id_priv->lock, flags);
947 		break;
948 	case IW_CM_STATE_DESTROYING:
949 		break;
950 	default:
951 		BUG();
952 	}
953 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
954 
955 	return ret;
956 }
957 
958 static int process_event(struct iwcm_id_private *cm_id_priv,
959 			 struct iw_cm_event *iw_event)
960 {
961 	int ret = 0;
962 
963 	switch (iw_event->event) {
964 	case IW_CM_EVENT_CONNECT_REQUEST:
965 		cm_conn_req_handler(cm_id_priv, iw_event);
966 		break;
967 	case IW_CM_EVENT_CONNECT_REPLY:
968 		ret = cm_conn_rep_handler(cm_id_priv, iw_event);
969 		break;
970 	case IW_CM_EVENT_ESTABLISHED:
971 		ret = cm_conn_est_handler(cm_id_priv, iw_event);
972 		break;
973 	case IW_CM_EVENT_DISCONNECT:
974 		cm_disconnect_handler(cm_id_priv, iw_event);
975 		break;
976 	case IW_CM_EVENT_CLOSE:
977 		ret = cm_close_handler(cm_id_priv, iw_event);
978 		break;
979 	default:
980 		BUG();
981 	}
982 
983 	return ret;
984 }
985 
986 /*
987  * Process events on the work_list for the cm_id. If the callback
988  * function requests that the cm_id be deleted, a flag is set in the
989  * cm_id flags to indicate that when the last reference is
990  * removed, the cm_id is to be destroyed. This is necessary to
991  * distinguish between an object that will be destroyed by the app
992  * thread asleep on the destroy_comp list vs. an object destroyed
993  * here synchronously when the last reference is removed.
994  */
995 static void cm_work_handler(struct work_struct *_work)
996 {
997 	struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
998 	struct iw_cm_event levent;
999 	struct iwcm_id_private *cm_id_priv = work->cm_id;
1000 	unsigned long flags;
1001 	int empty;
1002 	int ret = 0;
1003 	int destroy_id;
1004 
1005 	spin_lock_irqsave(&cm_id_priv->lock, flags);
1006 	empty = list_empty(&cm_id_priv->work_list);
1007 	while (!empty) {
1008 		work = list_entry(cm_id_priv->work_list.next,
1009 				  struct iwcm_work, list);
1010 		list_del_init(&work->list);
1011 		empty = list_empty(&cm_id_priv->work_list);
1012 		levent = work->event;
1013 		put_work(work);
1014 		spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1015 
1016 		ret = process_event(cm_id_priv, &levent);
1017 		if (ret) {
1018 			set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
1019 			destroy_cm_id(&cm_id_priv->id);
1020 		}
1021 		BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
1022 		destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
1023 		if (iwcm_deref_id(cm_id_priv)) {
1024 			if (destroy_id) {
1025 				BUG_ON(!list_empty(&cm_id_priv->work_list));
1026 				free_cm_id(cm_id_priv);
1027 			}
1028 			return;
1029 		}
1030 		if (empty)
1031 			return;
1032 		spin_lock_irqsave(&cm_id_priv->lock, flags);
1033 	}
1034 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1035 }
1036 
1037 /*
1038  * This function is called on interrupt context. Schedule events on
1039  * the iwcm_wq thread to allow callback functions to downcall into
1040  * the CM and/or block.  Events are queued to a per-CM_ID
1041  * work_list. If this is the first event on the work_list, the work
1042  * element is also queued on the iwcm_wq thread.
1043  *
1044  * Each event holds a reference on the cm_id. Until the last posted
1045  * event has been delivered and processed, the cm_id cannot be
1046  * deleted.
1047  *
1048  * Returns:
1049  * 	      0	- the event was handled.
1050  *	-ENOMEM	- the event was not handled due to lack of resources.
1051  */
1052 static int cm_event_handler(struct iw_cm_id *cm_id,
1053 			     struct iw_cm_event *iw_event)
1054 {
1055 	struct iwcm_work *work;
1056 	struct iwcm_id_private *cm_id_priv;
1057 	unsigned long flags;
1058 	int ret = 0;
1059 
1060 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1061 
1062 	spin_lock_irqsave(&cm_id_priv->lock, flags);
1063 	work = get_work(cm_id_priv);
1064 	if (!work) {
1065 		ret = -ENOMEM;
1066 		goto out;
1067 	}
1068 
1069 	INIT_WORK(&work->work, cm_work_handler);
1070 	work->cm_id = cm_id_priv;
1071 	work->event = *iw_event;
1072 
1073 	if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
1074 	     work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
1075 	    work->event.private_data_len) {
1076 		ret = copy_private_data(&work->event);
1077 		if (ret) {
1078 			put_work(work);
1079 			goto out;
1080 		}
1081 	}
1082 
1083 	atomic_inc(&cm_id_priv->refcount);
1084 	if (list_empty(&cm_id_priv->work_list)) {
1085 		list_add_tail(&work->list, &cm_id_priv->work_list);
1086 		queue_work(iwcm_wq, &work->work);
1087 	} else
1088 		list_add_tail(&work->list, &cm_id_priv->work_list);
1089 out:
1090 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1091 	return ret;
1092 }
1093 
1094 static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
1095 				  struct ib_qp_attr *qp_attr,
1096 				  int *qp_attr_mask)
1097 {
1098 	unsigned long flags;
1099 	int ret;
1100 
1101 	spin_lock_irqsave(&cm_id_priv->lock, flags);
1102 	switch (cm_id_priv->state) {
1103 	case IW_CM_STATE_IDLE:
1104 	case IW_CM_STATE_CONN_SENT:
1105 	case IW_CM_STATE_CONN_RECV:
1106 	case IW_CM_STATE_ESTABLISHED:
1107 		*qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
1108 		qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
1109 					   IB_ACCESS_REMOTE_READ;
1110 		ret = 0;
1111 		break;
1112 	default:
1113 		ret = -EINVAL;
1114 		break;
1115 	}
1116 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1117 	return ret;
1118 }
1119 
1120 static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
1121 				  struct ib_qp_attr *qp_attr,
1122 				  int *qp_attr_mask)
1123 {
1124 	unsigned long flags;
1125 	int ret;
1126 
1127 	spin_lock_irqsave(&cm_id_priv->lock, flags);
1128 	switch (cm_id_priv->state) {
1129 	case IW_CM_STATE_IDLE:
1130 	case IW_CM_STATE_CONN_SENT:
1131 	case IW_CM_STATE_CONN_RECV:
1132 	case IW_CM_STATE_ESTABLISHED:
1133 		*qp_attr_mask = 0;
1134 		ret = 0;
1135 		break;
1136 	default:
1137 		ret = -EINVAL;
1138 		break;
1139 	}
1140 	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1141 	return ret;
1142 }
1143 
1144 int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
1145 		       struct ib_qp_attr *qp_attr,
1146 		       int *qp_attr_mask)
1147 {
1148 	struct iwcm_id_private *cm_id_priv;
1149 	int ret;
1150 
1151 	cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1152 	switch (qp_attr->qp_state) {
1153 	case IB_QPS_INIT:
1154 	case IB_QPS_RTR:
1155 		ret = iwcm_init_qp_init_attr(cm_id_priv,
1156 					     qp_attr, qp_attr_mask);
1157 		break;
1158 	case IB_QPS_RTS:
1159 		ret = iwcm_init_qp_rts_attr(cm_id_priv,
1160 					    qp_attr, qp_attr_mask);
1161 		break;
1162 	default:
1163 		ret = -EINVAL;
1164 		break;
1165 	}
1166 	return ret;
1167 }
1168 EXPORT_SYMBOL(iw_cm_init_qp_attr);
1169 
1170 static int __init iw_cm_init(void)
1171 {
1172 	int ret;
1173 
1174 	ret = iwpm_init(RDMA_NL_IWCM);
1175 	if (ret)
1176 		pr_err("iw_cm: couldn't init iwpm\n");
1177 
1178 	ret = ibnl_add_client(RDMA_NL_IWCM, ARRAY_SIZE(iwcm_nl_cb_table),
1179 			      iwcm_nl_cb_table);
1180 	if (ret)
1181 		pr_err("iw_cm: couldn't register netlink callbacks\n");
1182 
1183 	iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
1184 	if (!iwcm_wq)
1185 		return -ENOMEM;
1186 
1187 	iwcm_ctl_table_hdr = register_net_sysctl(&init_net, "net/iw_cm",
1188 						 iwcm_ctl_table);
1189 	if (!iwcm_ctl_table_hdr) {
1190 		pr_err("iw_cm: couldn't register sysctl paths\n");
1191 		destroy_workqueue(iwcm_wq);
1192 		return -ENOMEM;
1193 	}
1194 
1195 	return 0;
1196 }
1197 
1198 static void __exit iw_cm_cleanup(void)
1199 {
1200 	unregister_net_sysctl_table(iwcm_ctl_table_hdr);
1201 	destroy_workqueue(iwcm_wq);
1202 	ibnl_remove_client(RDMA_NL_IWCM);
1203 	iwpm_exit(RDMA_NL_IWCM);
1204 }
1205 
1206 module_init(iw_cm_init);
1207 module_exit(iw_cm_cleanup);
1208