xref: /linux/net/smc/smc_ib.c (revision 3494bec0f6ac8ac06e0ad7c35933db345b2c5a83)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  IB infrastructure:
6  *  Establish SMC-R as an Infiniband Client to be notified about added and
7  *  removed IB devices of type RDMA.
8  *  Determine device and port characteristics for these IB devices.
9  *
10  *  Copyright IBM Corp. 2016
11  *
12  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
13  */
14 
15 #include <linux/random.h>
16 #include <linux/workqueue.h>
17 #include <linux/scatterlist.h>
18 #include <linux/wait.h>
19 #include <rdma/ib_verbs.h>
20 #include <rdma/ib_cache.h>
21 
22 #include "smc_pnet.h"
23 #include "smc_ib.h"
24 #include "smc_core.h"
25 #include "smc_wr.h"
26 #include "smc.h"
27 
28 #define SMC_MAX_CQE 32766	/* max. # of completion queue elements */
29 
30 #define SMC_QP_MIN_RNR_TIMER		5
31 #define SMC_QP_TIMEOUT			15 /* 4096 * 2 ** timeout usec */
32 #define SMC_QP_RETRY_CNT			7 /* 7: infinite */
33 #define SMC_QP_RNR_RETRY			7 /* 7: infinite */
34 
35 struct smc_ib_devices smc_ib_devices = {	/* smc-registered ib devices */
36 	.lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
37 	.list = LIST_HEAD_INIT(smc_ib_devices.list),
38 };
39 
40 #define SMC_LOCAL_SYSTEMID_RESET	"%%%%%%%"
41 
42 u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET;	/* unique system
43 								 * identifier
44 								 */
45 
46 static int smc_ib_modify_qp_init(struct smc_link *lnk)
47 {
48 	struct ib_qp_attr qp_attr;
49 
50 	memset(&qp_attr, 0, sizeof(qp_attr));
51 	qp_attr.qp_state = IB_QPS_INIT;
52 	qp_attr.pkey_index = 0;
53 	qp_attr.port_num = lnk->ibport;
54 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
55 				| IB_ACCESS_REMOTE_WRITE;
56 	return ib_modify_qp(lnk->roce_qp, &qp_attr,
57 			    IB_QP_STATE | IB_QP_PKEY_INDEX |
58 			    IB_QP_ACCESS_FLAGS | IB_QP_PORT);
59 }
60 
61 static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
62 {
63 	enum ib_qp_attr_mask qp_attr_mask =
64 		IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
65 		IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
66 	struct ib_qp_attr qp_attr;
67 
68 	memset(&qp_attr, 0, sizeof(qp_attr));
69 	qp_attr.qp_state = IB_QPS_RTR;
70 	qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
71 	qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
72 	rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
73 	rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
74 	rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
75 	memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
76 	       sizeof(lnk->peer_mac));
77 	qp_attr.dest_qp_num = lnk->peer_qpn;
78 	qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
79 	qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
80 					 * requests
81 					 */
82 	qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
83 
84 	return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
85 }
86 
87 int smc_ib_modify_qp_rts(struct smc_link *lnk)
88 {
89 	struct ib_qp_attr qp_attr;
90 
91 	memset(&qp_attr, 0, sizeof(qp_attr));
92 	qp_attr.qp_state = IB_QPS_RTS;
93 	qp_attr.timeout = SMC_QP_TIMEOUT;	/* local ack timeout */
94 	qp_attr.retry_cnt = SMC_QP_RETRY_CNT;	/* retry count */
95 	qp_attr.rnr_retry = SMC_QP_RNR_RETRY;	/* RNR retries, 7=infinite */
96 	qp_attr.sq_psn = lnk->psn_initial;	/* starting send packet seq # */
97 	qp_attr.max_rd_atomic = 1;	/* # of outstanding RDMA reads and
98 					 * atomic ops allowed
99 					 */
100 	return ib_modify_qp(lnk->roce_qp, &qp_attr,
101 			    IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
102 			    IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
103 			    IB_QP_MAX_QP_RD_ATOMIC);
104 }
105 
106 int smc_ib_modify_qp_reset(struct smc_link *lnk)
107 {
108 	struct ib_qp_attr qp_attr;
109 
110 	memset(&qp_attr, 0, sizeof(qp_attr));
111 	qp_attr.qp_state = IB_QPS_RESET;
112 	return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
113 }
114 
115 int smc_ib_ready_link(struct smc_link *lnk)
116 {
117 	struct smc_link_group *lgr = smc_get_lgr(lnk);
118 	int rc = 0;
119 
120 	rc = smc_ib_modify_qp_init(lnk);
121 	if (rc)
122 		goto out;
123 
124 	rc = smc_ib_modify_qp_rtr(lnk);
125 	if (rc)
126 		goto out;
127 	smc_wr_remember_qp_attr(lnk);
128 	rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
129 			      IB_CQ_SOLICITED_MASK);
130 	if (rc)
131 		goto out;
132 	rc = smc_wr_rx_post_init(lnk);
133 	if (rc)
134 		goto out;
135 	smc_wr_remember_qp_attr(lnk);
136 
137 	if (lgr->role == SMC_SERV) {
138 		rc = smc_ib_modify_qp_rts(lnk);
139 		if (rc)
140 			goto out;
141 		smc_wr_remember_qp_attr(lnk);
142 	}
143 out:
144 	return rc;
145 }
146 
147 static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
148 {
149 	const struct ib_gid_attr *attr;
150 	int rc;
151 
152 	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
153 	if (IS_ERR(attr))
154 		return -ENODEV;
155 
156 	rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
157 	rdma_put_gid_attr(attr);
158 	return rc;
159 }
160 
161 /* Create an identifier unique for this instance of SMC-R.
162  * The MAC-address of the first active registered IB device
163  * plus a random 2-byte number is used to create this identifier.
164  * This name is delivered to the peer during connection initialization.
165  */
166 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
167 						u8 ibport)
168 {
169 	memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
170 	       sizeof(smcibdev->mac[ibport - 1]));
171 	get_random_bytes(&local_systemid[0], 2);
172 }
173 
174 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
175 {
176 	return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
177 }
178 
179 /* determine the gid for an ib-device port and vlan id */
180 int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
181 			 unsigned short vlan_id, u8 gid[], u8 *sgid_index)
182 {
183 	const struct ib_gid_attr *attr;
184 	const struct net_device *ndev;
185 	int i;
186 
187 	for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
188 		attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
189 		if (IS_ERR(attr))
190 			continue;
191 
192 		rcu_read_lock();
193 		ndev = rdma_read_gid_attr_ndev_rcu(attr);
194 		if (!IS_ERR(ndev) &&
195 		    ((!vlan_id && !is_vlan_dev(attr->ndev)) ||
196 		     (vlan_id && is_vlan_dev(attr->ndev) &&
197 		      vlan_dev_vlan_id(attr->ndev) == vlan_id)) &&
198 		    attr->gid_type == IB_GID_TYPE_ROCE) {
199 			rcu_read_unlock();
200 			if (gid)
201 				memcpy(gid, &attr->gid, SMC_GID_SIZE);
202 			if (sgid_index)
203 				*sgid_index = attr->index;
204 			rdma_put_gid_attr(attr);
205 			return 0;
206 		}
207 		rcu_read_unlock();
208 		rdma_put_gid_attr(attr);
209 	}
210 	return -ENODEV;
211 }
212 
213 static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
214 {
215 	int rc;
216 
217 	memset(&smcibdev->pattr[ibport - 1], 0,
218 	       sizeof(smcibdev->pattr[ibport - 1]));
219 	rc = ib_query_port(smcibdev->ibdev, ibport,
220 			   &smcibdev->pattr[ibport - 1]);
221 	if (rc)
222 		goto out;
223 	/* the SMC protocol requires specification of the RoCE MAC address */
224 	rc = smc_ib_fill_mac(smcibdev, ibport);
225 	if (rc)
226 		goto out;
227 	if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
228 		     sizeof(local_systemid)) &&
229 	    smc_ib_port_active(smcibdev, ibport))
230 		/* create unique system identifier */
231 		smc_ib_define_local_systemid(smcibdev, ibport);
232 out:
233 	return rc;
234 }
235 
236 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
237 static void smc_ib_port_event_work(struct work_struct *work)
238 {
239 	struct smc_ib_device *smcibdev = container_of(
240 		work, struct smc_ib_device, port_event_work);
241 	u8 port_idx;
242 
243 	for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
244 		smc_ib_remember_port_attr(smcibdev, port_idx + 1);
245 		clear_bit(port_idx, &smcibdev->port_event_mask);
246 		if (!smc_ib_port_active(smcibdev, port_idx + 1)) {
247 			set_bit(port_idx, smcibdev->ports_going_away);
248 			smc_port_terminate(smcibdev, port_idx + 1);
249 		} else {
250 			clear_bit(port_idx, smcibdev->ports_going_away);
251 		}
252 	}
253 }
254 
255 /* can be called in IRQ context */
256 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
257 					struct ib_event *ibevent)
258 {
259 	struct smc_ib_device *smcibdev;
260 	bool schedule = false;
261 	u8 port_idx;
262 
263 	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
264 
265 	switch (ibevent->event) {
266 	case IB_EVENT_DEVICE_FATAL:
267 		/* terminate all ports on device */
268 		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++) {
269 			set_bit(port_idx, &smcibdev->port_event_mask);
270 			if (!test_and_set_bit(port_idx,
271 					      smcibdev->ports_going_away))
272 				schedule = true;
273 		}
274 		if (schedule)
275 			schedule_work(&smcibdev->port_event_work);
276 		break;
277 	case IB_EVENT_PORT_ACTIVE:
278 		port_idx = ibevent->element.port_num - 1;
279 		if (port_idx >= SMC_MAX_PORTS)
280 			break;
281 		set_bit(port_idx, &smcibdev->port_event_mask);
282 		if (test_and_clear_bit(port_idx, smcibdev->ports_going_away))
283 			schedule_work(&smcibdev->port_event_work);
284 		break;
285 	case IB_EVENT_PORT_ERR:
286 		port_idx = ibevent->element.port_num - 1;
287 		if (port_idx >= SMC_MAX_PORTS)
288 			break;
289 		set_bit(port_idx, &smcibdev->port_event_mask);
290 		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
291 			schedule_work(&smcibdev->port_event_work);
292 		break;
293 	case IB_EVENT_GID_CHANGE:
294 		port_idx = ibevent->element.port_num - 1;
295 		if (port_idx >= SMC_MAX_PORTS)
296 			break;
297 		set_bit(port_idx, &smcibdev->port_event_mask);
298 		schedule_work(&smcibdev->port_event_work);
299 		break;
300 	default:
301 		break;
302 	}
303 }
304 
305 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
306 {
307 	if (lnk->roce_pd)
308 		ib_dealloc_pd(lnk->roce_pd);
309 	lnk->roce_pd = NULL;
310 }
311 
312 int smc_ib_create_protection_domain(struct smc_link *lnk)
313 {
314 	int rc;
315 
316 	lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
317 	rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
318 	if (IS_ERR(lnk->roce_pd))
319 		lnk->roce_pd = NULL;
320 	return rc;
321 }
322 
323 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
324 {
325 	struct smc_link *lnk = (struct smc_link *)priv;
326 	struct smc_ib_device *smcibdev = lnk->smcibdev;
327 	u8 port_idx;
328 
329 	switch (ibevent->event) {
330 	case IB_EVENT_QP_FATAL:
331 	case IB_EVENT_QP_ACCESS_ERR:
332 		port_idx = ibevent->element.qp->port - 1;
333 		if (port_idx >= SMC_MAX_PORTS)
334 			break;
335 		set_bit(port_idx, &smcibdev->port_event_mask);
336 		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
337 			schedule_work(&smcibdev->port_event_work);
338 		break;
339 	default:
340 		break;
341 	}
342 }
343 
344 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
345 {
346 	if (lnk->roce_qp)
347 		ib_destroy_qp(lnk->roce_qp);
348 	lnk->roce_qp = NULL;
349 }
350 
351 /* create a queue pair within the protection domain for a link */
352 int smc_ib_create_queue_pair(struct smc_link *lnk)
353 {
354 	struct ib_qp_init_attr qp_attr = {
355 		.event_handler = smc_ib_qp_event_handler,
356 		.qp_context = lnk,
357 		.send_cq = lnk->smcibdev->roce_cq_send,
358 		.recv_cq = lnk->smcibdev->roce_cq_recv,
359 		.srq = NULL,
360 		.cap = {
361 				/* include unsolicited rdma_writes as well,
362 				 * there are max. 2 RDMA_WRITE per 1 WR_SEND
363 				 */
364 			.max_send_wr = SMC_WR_BUF_CNT * 3,
365 			.max_recv_wr = SMC_WR_BUF_CNT * 3,
366 			.max_send_sge = SMC_IB_MAX_SEND_SGE,
367 			.max_recv_sge = 1,
368 		},
369 		.sq_sig_type = IB_SIGNAL_REQ_WR,
370 		.qp_type = IB_QPT_RC,
371 	};
372 	int rc;
373 
374 	lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
375 	rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
376 	if (IS_ERR(lnk->roce_qp))
377 		lnk->roce_qp = NULL;
378 	else
379 		smc_wr_remember_qp_attr(lnk);
380 	return rc;
381 }
382 
383 void smc_ib_put_memory_region(struct ib_mr *mr)
384 {
385 	ib_dereg_mr(mr);
386 }
387 
388 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
389 {
390 	unsigned int offset = 0;
391 	int sg_num;
392 
393 	/* map the largest prefix of a dma mapped SG list */
394 	sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
395 			      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
396 			      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
397 			      &offset, PAGE_SIZE);
398 
399 	return sg_num;
400 }
401 
402 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
403 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
404 			     struct smc_buf_desc *buf_slot)
405 {
406 	if (buf_slot->mr_rx[SMC_SINGLE_LINK])
407 		return 0; /* already done */
408 
409 	buf_slot->mr_rx[SMC_SINGLE_LINK] =
410 		ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
411 	if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
412 		int rc;
413 
414 		rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
415 		buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
416 		return rc;
417 	}
418 
419 	if (smc_ib_map_mr_sg(buf_slot) != 1)
420 		return -EINVAL;
421 
422 	return 0;
423 }
424 
425 /* synchronize buffer usage for cpu access */
426 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
427 			    struct smc_buf_desc *buf_slot,
428 			    enum dma_data_direction data_direction)
429 {
430 	struct scatterlist *sg;
431 	unsigned int i;
432 
433 	/* for now there is just one DMA address */
434 	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
435 		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
436 		if (!sg_dma_len(sg))
437 			break;
438 		ib_dma_sync_single_for_cpu(smcibdev->ibdev,
439 					   sg_dma_address(sg),
440 					   sg_dma_len(sg),
441 					   data_direction);
442 	}
443 }
444 
445 /* synchronize buffer usage for device access */
446 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
447 			       struct smc_buf_desc *buf_slot,
448 			       enum dma_data_direction data_direction)
449 {
450 	struct scatterlist *sg;
451 	unsigned int i;
452 
453 	/* for now there is just one DMA address */
454 	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
455 		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
456 		if (!sg_dma_len(sg))
457 			break;
458 		ib_dma_sync_single_for_device(smcibdev->ibdev,
459 					      sg_dma_address(sg),
460 					      sg_dma_len(sg),
461 					      data_direction);
462 	}
463 }
464 
465 /* Map a new TX or RX buffer SG-table to DMA */
466 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
467 		      struct smc_buf_desc *buf_slot,
468 		      enum dma_data_direction data_direction)
469 {
470 	int mapped_nents;
471 
472 	mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
473 				     buf_slot->sgt[SMC_SINGLE_LINK].sgl,
474 				     buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
475 				     data_direction);
476 	if (!mapped_nents)
477 		return -ENOMEM;
478 
479 	return mapped_nents;
480 }
481 
482 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
483 			 struct smc_buf_desc *buf_slot,
484 			 enum dma_data_direction data_direction)
485 {
486 	if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
487 		return; /* already unmapped */
488 
489 	ib_dma_unmap_sg(smcibdev->ibdev,
490 			buf_slot->sgt[SMC_SINGLE_LINK].sgl,
491 			buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
492 			data_direction);
493 	buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
494 }
495 
496 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
497 {
498 	struct ib_cq_init_attr cqattr =	{
499 		.cqe = SMC_MAX_CQE, .comp_vector = 0 };
500 	int cqe_size_order, smc_order;
501 	long rc;
502 
503 	/* the calculated number of cq entries fits to mlx5 cq allocation */
504 	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
505 	smc_order = MAX_ORDER - cqe_size_order - 1;
506 	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
507 		cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
508 	smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
509 					      smc_wr_tx_cq_handler, NULL,
510 					      smcibdev, &cqattr);
511 	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
512 	if (IS_ERR(smcibdev->roce_cq_send)) {
513 		smcibdev->roce_cq_send = NULL;
514 		return rc;
515 	}
516 	smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
517 					      smc_wr_rx_cq_handler, NULL,
518 					      smcibdev, &cqattr);
519 	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
520 	if (IS_ERR(smcibdev->roce_cq_recv)) {
521 		smcibdev->roce_cq_recv = NULL;
522 		goto err;
523 	}
524 	smc_wr_add_dev(smcibdev);
525 	smcibdev->initialized = 1;
526 	return rc;
527 
528 err:
529 	ib_destroy_cq(smcibdev->roce_cq_send);
530 	return rc;
531 }
532 
533 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
534 {
535 	if (!smcibdev->initialized)
536 		return;
537 	smcibdev->initialized = 0;
538 	ib_destroy_cq(smcibdev->roce_cq_recv);
539 	ib_destroy_cq(smcibdev->roce_cq_send);
540 	smc_wr_remove_dev(smcibdev);
541 }
542 
543 static struct ib_client smc_ib_client;
544 
545 /* callback function for ib_register_client() */
546 static void smc_ib_add_dev(struct ib_device *ibdev)
547 {
548 	struct smc_ib_device *smcibdev;
549 	u8 port_cnt;
550 	int i;
551 
552 	if (ibdev->node_type != RDMA_NODE_IB_CA)
553 		return;
554 
555 	smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
556 	if (!smcibdev)
557 		return;
558 
559 	smcibdev->ibdev = ibdev;
560 	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
561 	atomic_set(&smcibdev->lnk_cnt, 0);
562 	init_waitqueue_head(&smcibdev->lnks_deleted);
563 	spin_lock(&smc_ib_devices.lock);
564 	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
565 	spin_unlock(&smc_ib_devices.lock);
566 	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
567 	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
568 			      smc_ib_global_event_handler);
569 	ib_register_event_handler(&smcibdev->event_handler);
570 
571 	/* trigger reading of the port attributes */
572 	port_cnt = smcibdev->ibdev->phys_port_cnt;
573 	for (i = 0;
574 	     i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
575 	     i++) {
576 		set_bit(i, &smcibdev->port_event_mask);
577 		/* determine pnetids of the port */
578 		smc_pnetid_by_dev_port(ibdev->dev.parent, i,
579 				       smcibdev->pnetid[i]);
580 	}
581 	schedule_work(&smcibdev->port_event_work);
582 }
583 
584 /* callback function for ib_unregister_client() */
585 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
586 {
587 	struct smc_ib_device *smcibdev;
588 
589 	smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
590 	ib_set_client_data(ibdev, &smc_ib_client, NULL);
591 	spin_lock(&smc_ib_devices.lock);
592 	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
593 	spin_unlock(&smc_ib_devices.lock);
594 	smc_smcr_terminate_all(smcibdev);
595 	smc_ib_cleanup_per_ibdev(smcibdev);
596 	ib_unregister_event_handler(&smcibdev->event_handler);
597 	kfree(smcibdev);
598 }
599 
600 static struct ib_client smc_ib_client = {
601 	.name	= "smc_ib",
602 	.add	= smc_ib_add_dev,
603 	.remove = smc_ib_remove_dev,
604 };
605 
606 int __init smc_ib_register_client(void)
607 {
608 	return ib_register_client(&smc_ib_client);
609 }
610 
611 void smc_ib_unregister_client(void)
612 {
613 	ib_unregister_client(&smc_ib_client);
614 }
615