xref: /linux/net/smc/smc_ib.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd)
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 	u8 port_idx;
261 
262 	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
263 
264 	switch (ibevent->event) {
265 	case IB_EVENT_DEVICE_FATAL:
266 		/* terminate all ports on device */
267 		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++) {
268 			set_bit(port_idx, &smcibdev->port_event_mask);
269 			set_bit(port_idx, smcibdev->ports_going_away);
270 		}
271 		schedule_work(&smcibdev->port_event_work);
272 		break;
273 	case IB_EVENT_PORT_ERR:
274 	case IB_EVENT_PORT_ACTIVE:
275 	case IB_EVENT_GID_CHANGE:
276 		port_idx = ibevent->element.port_num - 1;
277 		if (port_idx < SMC_MAX_PORTS) {
278 			set_bit(port_idx, &smcibdev->port_event_mask);
279 			if (ibevent->event == IB_EVENT_PORT_ERR)
280 				set_bit(port_idx, smcibdev->ports_going_away);
281 			else if (ibevent->event == IB_EVENT_PORT_ACTIVE)
282 				clear_bit(port_idx, smcibdev->ports_going_away);
283 			schedule_work(&smcibdev->port_event_work);
284 		}
285 		break;
286 	default:
287 		break;
288 	}
289 }
290 
291 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
292 {
293 	if (lnk->roce_pd)
294 		ib_dealloc_pd(lnk->roce_pd);
295 	lnk->roce_pd = NULL;
296 }
297 
298 int smc_ib_create_protection_domain(struct smc_link *lnk)
299 {
300 	int rc;
301 
302 	lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
303 	rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
304 	if (IS_ERR(lnk->roce_pd))
305 		lnk->roce_pd = NULL;
306 	return rc;
307 }
308 
309 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
310 {
311 	struct smc_link *lnk = (struct smc_link *)priv;
312 	struct smc_ib_device *smcibdev = lnk->smcibdev;
313 	u8 port_idx;
314 
315 	switch (ibevent->event) {
316 	case IB_EVENT_QP_FATAL:
317 	case IB_EVENT_QP_ACCESS_ERR:
318 		port_idx = ibevent->element.qp->port - 1;
319 		if (port_idx < SMC_MAX_PORTS) {
320 			set_bit(port_idx, &smcibdev->port_event_mask);
321 			set_bit(port_idx, smcibdev->ports_going_away);
322 			schedule_work(&smcibdev->port_event_work);
323 		}
324 		break;
325 	default:
326 		break;
327 	}
328 }
329 
330 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
331 {
332 	if (lnk->roce_qp)
333 		ib_destroy_qp(lnk->roce_qp);
334 	lnk->roce_qp = NULL;
335 }
336 
337 /* create a queue pair within the protection domain for a link */
338 int smc_ib_create_queue_pair(struct smc_link *lnk)
339 {
340 	struct ib_qp_init_attr qp_attr = {
341 		.event_handler = smc_ib_qp_event_handler,
342 		.qp_context = lnk,
343 		.send_cq = lnk->smcibdev->roce_cq_send,
344 		.recv_cq = lnk->smcibdev->roce_cq_recv,
345 		.srq = NULL,
346 		.cap = {
347 				/* include unsolicited rdma_writes as well,
348 				 * there are max. 2 RDMA_WRITE per 1 WR_SEND
349 				 */
350 			.max_send_wr = SMC_WR_BUF_CNT * 3,
351 			.max_recv_wr = SMC_WR_BUF_CNT * 3,
352 			.max_send_sge = SMC_IB_MAX_SEND_SGE,
353 			.max_recv_sge = 1,
354 		},
355 		.sq_sig_type = IB_SIGNAL_REQ_WR,
356 		.qp_type = IB_QPT_RC,
357 	};
358 	int rc;
359 
360 	lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
361 	rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
362 	if (IS_ERR(lnk->roce_qp))
363 		lnk->roce_qp = NULL;
364 	else
365 		smc_wr_remember_qp_attr(lnk);
366 	return rc;
367 }
368 
369 void smc_ib_put_memory_region(struct ib_mr *mr)
370 {
371 	ib_dereg_mr(mr);
372 }
373 
374 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
375 {
376 	unsigned int offset = 0;
377 	int sg_num;
378 
379 	/* map the largest prefix of a dma mapped SG list */
380 	sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
381 			      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
382 			      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
383 			      &offset, PAGE_SIZE);
384 
385 	return sg_num;
386 }
387 
388 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
389 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
390 			     struct smc_buf_desc *buf_slot)
391 {
392 	if (buf_slot->mr_rx[SMC_SINGLE_LINK])
393 		return 0; /* already done */
394 
395 	buf_slot->mr_rx[SMC_SINGLE_LINK] =
396 		ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
397 	if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
398 		int rc;
399 
400 		rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
401 		buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
402 		return rc;
403 	}
404 
405 	if (smc_ib_map_mr_sg(buf_slot) != 1)
406 		return -EINVAL;
407 
408 	return 0;
409 }
410 
411 /* synchronize buffer usage for cpu access */
412 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
413 			    struct smc_buf_desc *buf_slot,
414 			    enum dma_data_direction data_direction)
415 {
416 	struct scatterlist *sg;
417 	unsigned int i;
418 
419 	/* for now there is just one DMA address */
420 	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
421 		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
422 		if (!sg_dma_len(sg))
423 			break;
424 		ib_dma_sync_single_for_cpu(smcibdev->ibdev,
425 					   sg_dma_address(sg),
426 					   sg_dma_len(sg),
427 					   data_direction);
428 	}
429 }
430 
431 /* synchronize buffer usage for device access */
432 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
433 			       struct smc_buf_desc *buf_slot,
434 			       enum dma_data_direction data_direction)
435 {
436 	struct scatterlist *sg;
437 	unsigned int i;
438 
439 	/* for now there is just one DMA address */
440 	for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
441 		    buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
442 		if (!sg_dma_len(sg))
443 			break;
444 		ib_dma_sync_single_for_device(smcibdev->ibdev,
445 					      sg_dma_address(sg),
446 					      sg_dma_len(sg),
447 					      data_direction);
448 	}
449 }
450 
451 /* Map a new TX or RX buffer SG-table to DMA */
452 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
453 		      struct smc_buf_desc *buf_slot,
454 		      enum dma_data_direction data_direction)
455 {
456 	int mapped_nents;
457 
458 	mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
459 				     buf_slot->sgt[SMC_SINGLE_LINK].sgl,
460 				     buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
461 				     data_direction);
462 	if (!mapped_nents)
463 		return -ENOMEM;
464 
465 	return mapped_nents;
466 }
467 
468 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
469 			 struct smc_buf_desc *buf_slot,
470 			 enum dma_data_direction data_direction)
471 {
472 	if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
473 		return; /* already unmapped */
474 
475 	ib_dma_unmap_sg(smcibdev->ibdev,
476 			buf_slot->sgt[SMC_SINGLE_LINK].sgl,
477 			buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
478 			data_direction);
479 	buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
480 }
481 
482 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
483 {
484 	struct ib_cq_init_attr cqattr =	{
485 		.cqe = SMC_MAX_CQE, .comp_vector = 0 };
486 	int cqe_size_order, smc_order;
487 	long rc;
488 
489 	/* the calculated number of cq entries fits to mlx5 cq allocation */
490 	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
491 	smc_order = MAX_ORDER - cqe_size_order - 1;
492 	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
493 		cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
494 	smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
495 					      smc_wr_tx_cq_handler, NULL,
496 					      smcibdev, &cqattr);
497 	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
498 	if (IS_ERR(smcibdev->roce_cq_send)) {
499 		smcibdev->roce_cq_send = NULL;
500 		return rc;
501 	}
502 	smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
503 					      smc_wr_rx_cq_handler, NULL,
504 					      smcibdev, &cqattr);
505 	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
506 	if (IS_ERR(smcibdev->roce_cq_recv)) {
507 		smcibdev->roce_cq_recv = NULL;
508 		goto err;
509 	}
510 	smc_wr_add_dev(smcibdev);
511 	smcibdev->initialized = 1;
512 	return rc;
513 
514 err:
515 	ib_destroy_cq(smcibdev->roce_cq_send);
516 	return rc;
517 }
518 
519 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
520 {
521 	if (!smcibdev->initialized)
522 		return;
523 	smcibdev->initialized = 0;
524 	ib_destroy_cq(smcibdev->roce_cq_recv);
525 	ib_destroy_cq(smcibdev->roce_cq_send);
526 	smc_wr_remove_dev(smcibdev);
527 }
528 
529 static struct ib_client smc_ib_client;
530 
531 /* callback function for ib_register_client() */
532 static void smc_ib_add_dev(struct ib_device *ibdev)
533 {
534 	struct smc_ib_device *smcibdev;
535 	u8 port_cnt;
536 	int i;
537 
538 	if (ibdev->node_type != RDMA_NODE_IB_CA)
539 		return;
540 
541 	smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
542 	if (!smcibdev)
543 		return;
544 
545 	smcibdev->ibdev = ibdev;
546 	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
547 	atomic_set(&smcibdev->lnk_cnt, 0);
548 	init_waitqueue_head(&smcibdev->lnks_deleted);
549 	spin_lock(&smc_ib_devices.lock);
550 	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
551 	spin_unlock(&smc_ib_devices.lock);
552 	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
553 	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
554 			      smc_ib_global_event_handler);
555 	ib_register_event_handler(&smcibdev->event_handler);
556 
557 	/* trigger reading of the port attributes */
558 	port_cnt = smcibdev->ibdev->phys_port_cnt;
559 	for (i = 0;
560 	     i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
561 	     i++) {
562 		set_bit(i, &smcibdev->port_event_mask);
563 		/* determine pnetids of the port */
564 		smc_pnetid_by_dev_port(ibdev->dev.parent, i,
565 				       smcibdev->pnetid[i]);
566 	}
567 	schedule_work(&smcibdev->port_event_work);
568 }
569 
570 /* callback function for ib_unregister_client() */
571 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
572 {
573 	struct smc_ib_device *smcibdev;
574 
575 	smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
576 	ib_set_client_data(ibdev, &smc_ib_client, NULL);
577 	spin_lock(&smc_ib_devices.lock);
578 	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
579 	spin_unlock(&smc_ib_devices.lock);
580 	smc_smcr_terminate_all(smcibdev);
581 	smc_ib_cleanup_per_ibdev(smcibdev);
582 	ib_unregister_event_handler(&smcibdev->event_handler);
583 	kfree(smcibdev);
584 }
585 
586 static struct ib_client smc_ib_client = {
587 	.name	= "smc_ib",
588 	.add	= smc_ib_add_dev,
589 	.remove = smc_ib_remove_dev,
590 };
591 
592 int __init smc_ib_register_client(void)
593 {
594 	return ib_register_client(&smc_ib_client);
595 }
596 
597 void smc_ib_unregister_client(void)
598 {
599 	ib_unregister_client(&smc_ib_client);
600 }
601