xref: /openbmc/linux/drivers/infiniband/ulp/rtrs/rtrs.c (revision ed84ef1c)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * RDMA Transport Layer
4  *
5  * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6  * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7  * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8  */
9 #undef pr_fmt
10 #define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
11 
12 #include <linux/module.h>
13 #include <linux/inet.h>
14 
15 #include "rtrs-pri.h"
16 #include "rtrs-log.h"
17 
18 MODULE_DESCRIPTION("RDMA Transport Core");
19 MODULE_LICENSE("GPL");
20 
21 struct rtrs_iu *rtrs_iu_alloc(u32 iu_num, size_t size, gfp_t gfp_mask,
22 			      struct ib_device *dma_dev,
23 			      enum dma_data_direction dir,
24 			      void (*done)(struct ib_cq *cq, struct ib_wc *wc))
25 {
26 	struct rtrs_iu *ius, *iu;
27 	int i;
28 
29 	ius = kcalloc(iu_num, sizeof(*ius), gfp_mask);
30 	if (!ius)
31 		return NULL;
32 	for (i = 0; i < iu_num; i++) {
33 		iu = &ius[i];
34 		iu->direction = dir;
35 		iu->buf = kzalloc(size, gfp_mask);
36 		if (!iu->buf)
37 			goto err;
38 
39 		iu->dma_addr = ib_dma_map_single(dma_dev, iu->buf, size, dir);
40 		if (ib_dma_mapping_error(dma_dev, iu->dma_addr))
41 			goto err;
42 
43 		iu->cqe.done  = done;
44 		iu->size      = size;
45 	}
46 	return ius;
47 err:
48 	rtrs_iu_free(ius, dma_dev, i);
49 	return NULL;
50 }
51 EXPORT_SYMBOL_GPL(rtrs_iu_alloc);
52 
53 void rtrs_iu_free(struct rtrs_iu *ius, struct ib_device *ibdev, u32 queue_num)
54 {
55 	struct rtrs_iu *iu;
56 	int i;
57 
58 	if (!ius)
59 		return;
60 
61 	for (i = 0; i < queue_num; i++) {
62 		iu = &ius[i];
63 		ib_dma_unmap_single(ibdev, iu->dma_addr, iu->size, iu->direction);
64 		kfree(iu->buf);
65 	}
66 	kfree(ius);
67 }
68 EXPORT_SYMBOL_GPL(rtrs_iu_free);
69 
70 int rtrs_iu_post_recv(struct rtrs_con *con, struct rtrs_iu *iu)
71 {
72 	struct rtrs_sess *sess = con->sess;
73 	struct ib_recv_wr wr;
74 	struct ib_sge list;
75 
76 	list.addr   = iu->dma_addr;
77 	list.length = iu->size;
78 	list.lkey   = sess->dev->ib_pd->local_dma_lkey;
79 
80 	if (list.length == 0) {
81 		rtrs_wrn(con->sess,
82 			  "Posting receive work request failed, sg list is empty\n");
83 		return -EINVAL;
84 	}
85 	wr = (struct ib_recv_wr) {
86 		.wr_cqe  = &iu->cqe,
87 		.sg_list = &list,
88 		.num_sge = 1,
89 	};
90 
91 	return ib_post_recv(con->qp, &wr, NULL);
92 }
93 EXPORT_SYMBOL_GPL(rtrs_iu_post_recv);
94 
95 int rtrs_post_recv_empty(struct rtrs_con *con, struct ib_cqe *cqe)
96 {
97 	struct ib_recv_wr wr;
98 
99 	wr = (struct ib_recv_wr) {
100 		.wr_cqe  = cqe,
101 	};
102 
103 	return ib_post_recv(con->qp, &wr, NULL);
104 }
105 EXPORT_SYMBOL_GPL(rtrs_post_recv_empty);
106 
107 static int rtrs_post_send(struct ib_qp *qp, struct ib_send_wr *head,
108 			  struct ib_send_wr *wr, struct ib_send_wr *tail)
109 {
110 	if (head) {
111 		struct ib_send_wr *next = head;
112 
113 		while (next->next)
114 			next = next->next;
115 		next->next = wr;
116 	} else {
117 		head = wr;
118 	}
119 
120 	if (tail)
121 		wr->next = tail;
122 
123 	return ib_post_send(qp, head, NULL);
124 }
125 
126 int rtrs_iu_post_send(struct rtrs_con *con, struct rtrs_iu *iu, size_t size,
127 		       struct ib_send_wr *head)
128 {
129 	struct rtrs_sess *sess = con->sess;
130 	struct ib_send_wr wr;
131 	struct ib_sge list;
132 
133 	if (WARN_ON(size == 0))
134 		return -EINVAL;
135 
136 	list.addr   = iu->dma_addr;
137 	list.length = size;
138 	list.lkey   = sess->dev->ib_pd->local_dma_lkey;
139 
140 	wr = (struct ib_send_wr) {
141 		.wr_cqe     = &iu->cqe,
142 		.sg_list    = &list,
143 		.num_sge    = 1,
144 		.opcode     = IB_WR_SEND,
145 		.send_flags = IB_SEND_SIGNALED,
146 	};
147 
148 	return rtrs_post_send(con->qp, head, &wr, NULL);
149 }
150 EXPORT_SYMBOL_GPL(rtrs_iu_post_send);
151 
152 int rtrs_iu_post_rdma_write_imm(struct rtrs_con *con, struct rtrs_iu *iu,
153 				struct ib_sge *sge, unsigned int num_sge,
154 				u32 rkey, u64 rdma_addr, u32 imm_data,
155 				enum ib_send_flags flags,
156 				struct ib_send_wr *head,
157 				struct ib_send_wr *tail)
158 {
159 	struct ib_rdma_wr wr;
160 	int i;
161 
162 	wr = (struct ib_rdma_wr) {
163 		.wr.wr_cqe	  = &iu->cqe,
164 		.wr.sg_list	  = sge,
165 		.wr.num_sge	  = num_sge,
166 		.rkey		  = rkey,
167 		.remote_addr	  = rdma_addr,
168 		.wr.opcode	  = IB_WR_RDMA_WRITE_WITH_IMM,
169 		.wr.ex.imm_data = cpu_to_be32(imm_data),
170 		.wr.send_flags  = flags,
171 	};
172 
173 	/*
174 	 * If one of the sges has 0 size, the operation will fail with a
175 	 * length error
176 	 */
177 	for (i = 0; i < num_sge; i++)
178 		if (WARN_ON(sge[i].length == 0))
179 			return -EINVAL;
180 
181 	return rtrs_post_send(con->qp, head, &wr.wr, tail);
182 }
183 EXPORT_SYMBOL_GPL(rtrs_iu_post_rdma_write_imm);
184 
185 static int rtrs_post_rdma_write_imm_empty(struct rtrs_con *con,
186 					  struct ib_cqe *cqe,
187 					  u32 imm_data,
188 					  struct ib_send_wr *head)
189 {
190 	struct ib_rdma_wr wr;
191 	struct rtrs_sess *sess = con->sess;
192 	enum ib_send_flags sflags;
193 
194 	atomic_dec_if_positive(&con->sq_wr_avail);
195 	sflags = (atomic_inc_return(&con->wr_cnt) % sess->signal_interval) ?
196 		0 : IB_SEND_SIGNALED;
197 
198 	wr = (struct ib_rdma_wr) {
199 		.wr.wr_cqe	= cqe,
200 		.wr.send_flags	= sflags,
201 		.wr.opcode	= IB_WR_RDMA_WRITE_WITH_IMM,
202 		.wr.ex.imm_data	= cpu_to_be32(imm_data),
203 	};
204 
205 	return rtrs_post_send(con->qp, head, &wr.wr, NULL);
206 }
207 
208 static void qp_event_handler(struct ib_event *ev, void *ctx)
209 {
210 	struct rtrs_con *con = ctx;
211 
212 	switch (ev->event) {
213 	case IB_EVENT_COMM_EST:
214 		rtrs_info(con->sess, "QP event %s (%d) received\n",
215 			   ib_event_msg(ev->event), ev->event);
216 		rdma_notify(con->cm_id, IB_EVENT_COMM_EST);
217 		break;
218 	default:
219 		rtrs_info(con->sess, "Unhandled QP event %s (%d) received\n",
220 			   ib_event_msg(ev->event), ev->event);
221 		break;
222 	}
223 }
224 
225 static int create_cq(struct rtrs_con *con, int cq_vector, int nr_cqe,
226 		     enum ib_poll_context poll_ctx)
227 {
228 	struct rdma_cm_id *cm_id = con->cm_id;
229 	struct ib_cq *cq;
230 
231 	cq = ib_cq_pool_get(cm_id->device, nr_cqe, cq_vector, poll_ctx);
232 	if (IS_ERR(cq)) {
233 		rtrs_err(con->sess, "Creating completion queue failed, errno: %ld\n",
234 			  PTR_ERR(cq));
235 		return PTR_ERR(cq);
236 	}
237 	con->cq = cq;
238 	con->nr_cqe = nr_cqe;
239 
240 	return 0;
241 }
242 
243 static int create_qp(struct rtrs_con *con, struct ib_pd *pd,
244 		     u32 max_send_wr, u32 max_recv_wr, u32 max_sge)
245 {
246 	struct ib_qp_init_attr init_attr = {NULL};
247 	struct rdma_cm_id *cm_id = con->cm_id;
248 	int ret;
249 
250 	init_attr.cap.max_send_wr = max_send_wr;
251 	init_attr.cap.max_recv_wr = max_recv_wr;
252 	init_attr.cap.max_recv_sge = 1;
253 	init_attr.event_handler = qp_event_handler;
254 	init_attr.qp_context = con;
255 	init_attr.cap.max_send_sge = max_sge;
256 
257 	init_attr.qp_type = IB_QPT_RC;
258 	init_attr.send_cq = con->cq;
259 	init_attr.recv_cq = con->cq;
260 	init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
261 
262 	ret = rdma_create_qp(cm_id, pd, &init_attr);
263 	if (ret) {
264 		rtrs_err(con->sess, "Creating QP failed, err: %d\n", ret);
265 		return ret;
266 	}
267 	con->qp = cm_id->qp;
268 
269 	return ret;
270 }
271 
272 int rtrs_cq_qp_create(struct rtrs_sess *sess, struct rtrs_con *con,
273 		       u32 max_send_sge, int cq_vector, int nr_cqe,
274 		       u32 max_send_wr, u32 max_recv_wr,
275 		       enum ib_poll_context poll_ctx)
276 {
277 	int err;
278 
279 	err = create_cq(con, cq_vector, nr_cqe, poll_ctx);
280 	if (err)
281 		return err;
282 
283 	err = create_qp(con, sess->dev->ib_pd, max_send_wr, max_recv_wr,
284 			max_send_sge);
285 	if (err) {
286 		ib_cq_pool_put(con->cq, con->nr_cqe);
287 		con->cq = NULL;
288 		return err;
289 	}
290 	con->sess = sess;
291 
292 	return 0;
293 }
294 EXPORT_SYMBOL_GPL(rtrs_cq_qp_create);
295 
296 void rtrs_cq_qp_destroy(struct rtrs_con *con)
297 {
298 	if (con->qp) {
299 		rdma_destroy_qp(con->cm_id);
300 		con->qp = NULL;
301 	}
302 	if (con->cq) {
303 		ib_cq_pool_put(con->cq, con->nr_cqe);
304 		con->cq = NULL;
305 	}
306 }
307 EXPORT_SYMBOL_GPL(rtrs_cq_qp_destroy);
308 
309 static void schedule_hb(struct rtrs_sess *sess)
310 {
311 	queue_delayed_work(sess->hb_wq, &sess->hb_dwork,
312 			   msecs_to_jiffies(sess->hb_interval_ms));
313 }
314 
315 void rtrs_send_hb_ack(struct rtrs_sess *sess)
316 {
317 	struct rtrs_con *usr_con = sess->con[0];
318 	u32 imm;
319 	int err;
320 
321 	imm = rtrs_to_imm(RTRS_HB_ACK_IMM, 0);
322 	err = rtrs_post_rdma_write_imm_empty(usr_con, sess->hb_cqe, imm,
323 					     NULL);
324 	if (err) {
325 		rtrs_err(sess, "send HB ACK failed, errno: %d\n", err);
326 		sess->hb_err_handler(usr_con);
327 		return;
328 	}
329 }
330 EXPORT_SYMBOL_GPL(rtrs_send_hb_ack);
331 
332 static void hb_work(struct work_struct *work)
333 {
334 	struct rtrs_con *usr_con;
335 	struct rtrs_sess *sess;
336 	u32 imm;
337 	int err;
338 
339 	sess = container_of(to_delayed_work(work), typeof(*sess), hb_dwork);
340 	usr_con = sess->con[0];
341 
342 	if (sess->hb_missed_cnt > sess->hb_missed_max) {
343 		rtrs_err(sess, "HB missed max reached.\n");
344 		sess->hb_err_handler(usr_con);
345 		return;
346 	}
347 	if (sess->hb_missed_cnt++) {
348 		/* Reschedule work without sending hb */
349 		schedule_hb(sess);
350 		return;
351 	}
352 
353 	sess->hb_last_sent = ktime_get();
354 
355 	imm = rtrs_to_imm(RTRS_HB_MSG_IMM, 0);
356 	err = rtrs_post_rdma_write_imm_empty(usr_con, sess->hb_cqe, imm,
357 					     NULL);
358 	if (err) {
359 		rtrs_err(sess, "HB send failed, errno: %d\n", err);
360 		sess->hb_err_handler(usr_con);
361 		return;
362 	}
363 
364 	schedule_hb(sess);
365 }
366 
367 void rtrs_init_hb(struct rtrs_sess *sess, struct ib_cqe *cqe,
368 		  unsigned int interval_ms, unsigned int missed_max,
369 		  void (*err_handler)(struct rtrs_con *con),
370 		  struct workqueue_struct *wq)
371 {
372 	sess->hb_cqe = cqe;
373 	sess->hb_interval_ms = interval_ms;
374 	sess->hb_err_handler = err_handler;
375 	sess->hb_wq = wq;
376 	sess->hb_missed_max = missed_max;
377 	sess->hb_missed_cnt = 0;
378 	INIT_DELAYED_WORK(&sess->hb_dwork, hb_work);
379 }
380 EXPORT_SYMBOL_GPL(rtrs_init_hb);
381 
382 void rtrs_start_hb(struct rtrs_sess *sess)
383 {
384 	schedule_hb(sess);
385 }
386 EXPORT_SYMBOL_GPL(rtrs_start_hb);
387 
388 void rtrs_stop_hb(struct rtrs_sess *sess)
389 {
390 	cancel_delayed_work_sync(&sess->hb_dwork);
391 	sess->hb_missed_cnt = 0;
392 }
393 EXPORT_SYMBOL_GPL(rtrs_stop_hb);
394 
395 static int rtrs_str_gid_to_sockaddr(const char *addr, size_t len,
396 				     short port, struct sockaddr_storage *dst)
397 {
398 	struct sockaddr_ib *dst_ib = (struct sockaddr_ib *)dst;
399 	int ret;
400 
401 	/*
402 	 * We can use some of the IPv6 functions since GID is a valid
403 	 * IPv6 address format
404 	 */
405 	ret = in6_pton(addr, len, dst_ib->sib_addr.sib_raw, '\0', NULL);
406 	if (ret == 0)
407 		return -EINVAL;
408 
409 	dst_ib->sib_family = AF_IB;
410 	/*
411 	 * Use the same TCP server port number as the IB service ID
412 	 * on the IB port space range
413 	 */
414 	dst_ib->sib_sid = cpu_to_be64(RDMA_IB_IP_PS_IB | port);
415 	dst_ib->sib_sid_mask = cpu_to_be64(0xffffffffffffffffULL);
416 	dst_ib->sib_pkey = cpu_to_be16(0xffff);
417 
418 	return 0;
419 }
420 
421 /**
422  * rtrs_str_to_sockaddr() - Convert rtrs address string to sockaddr
423  * @addr:	String representation of an addr (IPv4, IPv6 or IB GID):
424  *              - "ip:192.168.1.1"
425  *              - "ip:fe80::200:5aee:feaa:20a2"
426  *              - "gid:fe80::200:5aee:feaa:20a2"
427  * @len:        String address length
428  * @port:	Destination port
429  * @dst:	Destination sockaddr structure
430  *
431  * Returns 0 if conversion successful. Non-zero on error.
432  */
433 static int rtrs_str_to_sockaddr(const char *addr, size_t len,
434 				u16 port, struct sockaddr_storage *dst)
435 {
436 	if (strncmp(addr, "gid:", 4) == 0) {
437 		return rtrs_str_gid_to_sockaddr(addr + 4, len - 4, port, dst);
438 	} else if (strncmp(addr, "ip:", 3) == 0) {
439 		char port_str[8];
440 		char *cpy;
441 		int err;
442 
443 		snprintf(port_str, sizeof(port_str), "%u", port);
444 		cpy = kstrndup(addr + 3, len - 3, GFP_KERNEL);
445 		err = cpy ? inet_pton_with_scope(&init_net, AF_UNSPEC,
446 						 cpy, port_str, dst) : -ENOMEM;
447 		kfree(cpy);
448 
449 		return err;
450 	}
451 	return -EPROTONOSUPPORT;
452 }
453 
454 /**
455  * sockaddr_to_str() - convert sockaddr to a string.
456  * @addr:	the sockadddr structure to be converted.
457  * @buf:	string containing socket addr.
458  * @len:	string length.
459  *
460  * The return value is the number of characters written into buf not
461  * including the trailing '\0'. If len is == 0 the function returns 0..
462  */
463 int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len)
464 {
465 
466 	switch (addr->sa_family) {
467 	case AF_IB:
468 		return scnprintf(buf, len, "gid:%pI6",
469 			&((struct sockaddr_ib *)addr)->sib_addr.sib_raw);
470 	case AF_INET:
471 		return scnprintf(buf, len, "ip:%pI4",
472 			&((struct sockaddr_in *)addr)->sin_addr);
473 	case AF_INET6:
474 		return scnprintf(buf, len, "ip:%pI6c",
475 			  &((struct sockaddr_in6 *)addr)->sin6_addr);
476 	}
477 	return scnprintf(buf, len, "<invalid address family>");
478 }
479 EXPORT_SYMBOL(sockaddr_to_str);
480 
481 /**
482  * rtrs_addr_to_str() - convert rtrs_addr to a string "src@dst"
483  * @addr:	the rtrs_addr structure to be converted
484  * @buf:	string containing source and destination addr of a path
485  *		separated by '@' I.e. "ip:1.1.1.1@ip:1.1.1.2"
486  *		"ip:1.1.1.1@ip:1.1.1.2".
487  * @len:	string length
488  *
489  * The return value is the number of characters written into buf not
490  * including the trailing '\0'.
491  */
492 int rtrs_addr_to_str(const struct rtrs_addr *addr, char *buf, size_t len)
493 {
494 	int cnt;
495 
496 	cnt = sockaddr_to_str((struct sockaddr *)addr->src,
497 			      buf, len);
498 	cnt += scnprintf(buf + cnt, len - cnt, "@");
499 	sockaddr_to_str((struct sockaddr *)addr->dst,
500 			buf + cnt, len - cnt);
501 	return cnt;
502 }
503 EXPORT_SYMBOL(rtrs_addr_to_str);
504 
505 /**
506  * rtrs_addr_to_sockaddr() - convert path string "src,dst" or "src@dst"
507  * to sockaddreses
508  * @str:	string containing source and destination addr of a path
509  *		separated by ',' or '@' I.e. "ip:1.1.1.1,ip:1.1.1.2" or
510  *		"ip:1.1.1.1@ip:1.1.1.2". If str contains only one address it's
511  *		considered to be destination.
512  * @len:	string length
513  * @port:	Destination port number.
514  * @addr:	will be set to the source/destination address or to NULL
515  *		if str doesn't contain any source address.
516  *
517  * Returns zero if conversion successful. Non-zero otherwise.
518  */
519 int rtrs_addr_to_sockaddr(const char *str, size_t len, u16 port,
520 			  struct rtrs_addr *addr)
521 {
522 	const char *d;
523 
524 	d = strchr(str, ',');
525 	if (!d)
526 		d = strchr(str, '@');
527 	if (d) {
528 		if (rtrs_str_to_sockaddr(str, d - str, 0, addr->src))
529 			return -EINVAL;
530 		d += 1;
531 		len -= d - str;
532 		str  = d;
533 
534 	} else {
535 		addr->src = NULL;
536 	}
537 	return rtrs_str_to_sockaddr(str, len, port, addr->dst);
538 }
539 EXPORT_SYMBOL(rtrs_addr_to_sockaddr);
540 
541 void rtrs_rdma_dev_pd_init(enum ib_pd_flags pd_flags,
542 			    struct rtrs_rdma_dev_pd *pool)
543 {
544 	WARN_ON(pool->ops && (!pool->ops->alloc ^ !pool->ops->free));
545 	INIT_LIST_HEAD(&pool->list);
546 	mutex_init(&pool->mutex);
547 	pool->pd_flags = pd_flags;
548 }
549 EXPORT_SYMBOL(rtrs_rdma_dev_pd_init);
550 
551 void rtrs_rdma_dev_pd_deinit(struct rtrs_rdma_dev_pd *pool)
552 {
553 	mutex_destroy(&pool->mutex);
554 	WARN_ON(!list_empty(&pool->list));
555 }
556 EXPORT_SYMBOL(rtrs_rdma_dev_pd_deinit);
557 
558 static void dev_free(struct kref *ref)
559 {
560 	struct rtrs_rdma_dev_pd *pool;
561 	struct rtrs_ib_dev *dev;
562 
563 	dev = container_of(ref, typeof(*dev), ref);
564 	pool = dev->pool;
565 
566 	mutex_lock(&pool->mutex);
567 	list_del(&dev->entry);
568 	mutex_unlock(&pool->mutex);
569 
570 	if (pool->ops && pool->ops->deinit)
571 		pool->ops->deinit(dev);
572 
573 	ib_dealloc_pd(dev->ib_pd);
574 
575 	if (pool->ops && pool->ops->free)
576 		pool->ops->free(dev);
577 	else
578 		kfree(dev);
579 }
580 
581 int rtrs_ib_dev_put(struct rtrs_ib_dev *dev)
582 {
583 	return kref_put(&dev->ref, dev_free);
584 }
585 EXPORT_SYMBOL(rtrs_ib_dev_put);
586 
587 static int rtrs_ib_dev_get(struct rtrs_ib_dev *dev)
588 {
589 	return kref_get_unless_zero(&dev->ref);
590 }
591 
592 struct rtrs_ib_dev *
593 rtrs_ib_dev_find_or_add(struct ib_device *ib_dev,
594 			 struct rtrs_rdma_dev_pd *pool)
595 {
596 	struct rtrs_ib_dev *dev;
597 
598 	mutex_lock(&pool->mutex);
599 	list_for_each_entry(dev, &pool->list, entry) {
600 		if (dev->ib_dev->node_guid == ib_dev->node_guid &&
601 		    rtrs_ib_dev_get(dev))
602 			goto out_unlock;
603 	}
604 	mutex_unlock(&pool->mutex);
605 	if (pool->ops && pool->ops->alloc)
606 		dev = pool->ops->alloc();
607 	else
608 		dev = kzalloc(sizeof(*dev), GFP_KERNEL);
609 	if (IS_ERR_OR_NULL(dev))
610 		goto out_err;
611 
612 	kref_init(&dev->ref);
613 	dev->pool = pool;
614 	dev->ib_dev = ib_dev;
615 	dev->ib_pd = ib_alloc_pd(ib_dev, pool->pd_flags);
616 	if (IS_ERR(dev->ib_pd))
617 		goto out_free_dev;
618 
619 	if (pool->ops && pool->ops->init && pool->ops->init(dev))
620 		goto out_free_pd;
621 
622 	mutex_lock(&pool->mutex);
623 	list_add(&dev->entry, &pool->list);
624 out_unlock:
625 	mutex_unlock(&pool->mutex);
626 	return dev;
627 
628 out_free_pd:
629 	ib_dealloc_pd(dev->ib_pd);
630 out_free_dev:
631 	if (pool->ops && pool->ops->free)
632 		pool->ops->free(dev);
633 	else
634 		kfree(dev);
635 out_err:
636 	return NULL;
637 }
638 EXPORT_SYMBOL(rtrs_ib_dev_find_or_add);
639