xref: /openbmc/linux/net/smc/smc_ib.c (revision 4c5a116a)
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 <linux/mutex.h>
20 #include <rdma/ib_verbs.h>
21 #include <rdma/ib_cache.h>
22 
23 #include "smc_pnet.h"
24 #include "smc_ib.h"
25 #include "smc_core.h"
26 #include "smc_wr.h"
27 #include "smc.h"
28 
29 #define SMC_MAX_CQE 32766	/* max. # of completion queue elements */
30 
31 #define SMC_QP_MIN_RNR_TIMER		5
32 #define SMC_QP_TIMEOUT			15 /* 4096 * 2 ** timeout usec */
33 #define SMC_QP_RETRY_CNT			7 /* 7: infinite */
34 #define SMC_QP_RNR_RETRY			7 /* 7: infinite */
35 
36 struct smc_ib_devices smc_ib_devices = {	/* smc-registered ib devices */
37 	.mutex = __MUTEX_INITIALIZER(smc_ib_devices.mutex),
38 	.list = LIST_HEAD_INIT(smc_ib_devices.list),
39 };
40 
41 u8 local_systemid[SMC_SYSTEMID_LEN];		/* unique system identifier */
42 
43 static int smc_ib_modify_qp_init(struct smc_link *lnk)
44 {
45 	struct ib_qp_attr qp_attr;
46 
47 	memset(&qp_attr, 0, sizeof(qp_attr));
48 	qp_attr.qp_state = IB_QPS_INIT;
49 	qp_attr.pkey_index = 0;
50 	qp_attr.port_num = lnk->ibport;
51 	qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
52 				| IB_ACCESS_REMOTE_WRITE;
53 	return ib_modify_qp(lnk->roce_qp, &qp_attr,
54 			    IB_QP_STATE | IB_QP_PKEY_INDEX |
55 			    IB_QP_ACCESS_FLAGS | IB_QP_PORT);
56 }
57 
58 static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
59 {
60 	enum ib_qp_attr_mask qp_attr_mask =
61 		IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
62 		IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
63 	struct ib_qp_attr qp_attr;
64 
65 	memset(&qp_attr, 0, sizeof(qp_attr));
66 	qp_attr.qp_state = IB_QPS_RTR;
67 	qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
68 	qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
69 	rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
70 	rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
71 	rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
72 	memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
73 	       sizeof(lnk->peer_mac));
74 	qp_attr.dest_qp_num = lnk->peer_qpn;
75 	qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
76 	qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
77 					 * requests
78 					 */
79 	qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
80 
81 	return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
82 }
83 
84 int smc_ib_modify_qp_rts(struct smc_link *lnk)
85 {
86 	struct ib_qp_attr qp_attr;
87 
88 	memset(&qp_attr, 0, sizeof(qp_attr));
89 	qp_attr.qp_state = IB_QPS_RTS;
90 	qp_attr.timeout = SMC_QP_TIMEOUT;	/* local ack timeout */
91 	qp_attr.retry_cnt = SMC_QP_RETRY_CNT;	/* retry count */
92 	qp_attr.rnr_retry = SMC_QP_RNR_RETRY;	/* RNR retries, 7=infinite */
93 	qp_attr.sq_psn = lnk->psn_initial;	/* starting send packet seq # */
94 	qp_attr.max_rd_atomic = 1;	/* # of outstanding RDMA reads and
95 					 * atomic ops allowed
96 					 */
97 	return ib_modify_qp(lnk->roce_qp, &qp_attr,
98 			    IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
99 			    IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
100 			    IB_QP_MAX_QP_RD_ATOMIC);
101 }
102 
103 int smc_ib_modify_qp_reset(struct smc_link *lnk)
104 {
105 	struct ib_qp_attr qp_attr;
106 
107 	memset(&qp_attr, 0, sizeof(qp_attr));
108 	qp_attr.qp_state = IB_QPS_RESET;
109 	return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
110 }
111 
112 int smc_ib_ready_link(struct smc_link *lnk)
113 {
114 	struct smc_link_group *lgr = smc_get_lgr(lnk);
115 	int rc = 0;
116 
117 	rc = smc_ib_modify_qp_init(lnk);
118 	if (rc)
119 		goto out;
120 
121 	rc = smc_ib_modify_qp_rtr(lnk);
122 	if (rc)
123 		goto out;
124 	smc_wr_remember_qp_attr(lnk);
125 	rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
126 			      IB_CQ_SOLICITED_MASK);
127 	if (rc)
128 		goto out;
129 	rc = smc_wr_rx_post_init(lnk);
130 	if (rc)
131 		goto out;
132 	smc_wr_remember_qp_attr(lnk);
133 
134 	if (lgr->role == SMC_SERV) {
135 		rc = smc_ib_modify_qp_rts(lnk);
136 		if (rc)
137 			goto out;
138 		smc_wr_remember_qp_attr(lnk);
139 	}
140 out:
141 	return rc;
142 }
143 
144 static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
145 {
146 	const struct ib_gid_attr *attr;
147 	int rc;
148 
149 	attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
150 	if (IS_ERR(attr))
151 		return -ENODEV;
152 
153 	rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
154 	rdma_put_gid_attr(attr);
155 	return rc;
156 }
157 
158 /* Create an identifier unique for this instance of SMC-R.
159  * The MAC-address of the first active registered IB device
160  * plus a random 2-byte number is used to create this identifier.
161  * This name is delivered to the peer during connection initialization.
162  */
163 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
164 						u8 ibport)
165 {
166 	memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
167 	       sizeof(smcibdev->mac[ibport - 1]));
168 }
169 
170 bool smc_ib_is_valid_local_systemid(void)
171 {
172 	return !is_zero_ether_addr(&local_systemid[2]);
173 }
174 
175 static void smc_ib_init_local_systemid(void)
176 {
177 	get_random_bytes(&local_systemid[0], 2);
178 }
179 
180 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
181 {
182 	return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
183 }
184 
185 /* determine the gid for an ib-device port and vlan id */
186 int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
187 			 unsigned short vlan_id, u8 gid[], u8 *sgid_index)
188 {
189 	const struct ib_gid_attr *attr;
190 	const struct net_device *ndev;
191 	int i;
192 
193 	for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
194 		attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
195 		if (IS_ERR(attr))
196 			continue;
197 
198 		rcu_read_lock();
199 		ndev = rdma_read_gid_attr_ndev_rcu(attr);
200 		if (!IS_ERR(ndev) &&
201 		    ((!vlan_id && !is_vlan_dev(attr->ndev)) ||
202 		     (vlan_id && is_vlan_dev(attr->ndev) &&
203 		      vlan_dev_vlan_id(attr->ndev) == vlan_id)) &&
204 		    attr->gid_type == IB_GID_TYPE_ROCE) {
205 			rcu_read_unlock();
206 			if (gid)
207 				memcpy(gid, &attr->gid, SMC_GID_SIZE);
208 			if (sgid_index)
209 				*sgid_index = attr->index;
210 			rdma_put_gid_attr(attr);
211 			return 0;
212 		}
213 		rcu_read_unlock();
214 		rdma_put_gid_attr(attr);
215 	}
216 	return -ENODEV;
217 }
218 
219 static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
220 {
221 	int rc;
222 
223 	memset(&smcibdev->pattr[ibport - 1], 0,
224 	       sizeof(smcibdev->pattr[ibport - 1]));
225 	rc = ib_query_port(smcibdev->ibdev, ibport,
226 			   &smcibdev->pattr[ibport - 1]);
227 	if (rc)
228 		goto out;
229 	/* the SMC protocol requires specification of the RoCE MAC address */
230 	rc = smc_ib_fill_mac(smcibdev, ibport);
231 	if (rc)
232 		goto out;
233 	if (!smc_ib_is_valid_local_systemid() &&
234 	    smc_ib_port_active(smcibdev, ibport))
235 		/* create unique system identifier */
236 		smc_ib_define_local_systemid(smcibdev, ibport);
237 out:
238 	return rc;
239 }
240 
241 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
242 static void smc_ib_port_event_work(struct work_struct *work)
243 {
244 	struct smc_ib_device *smcibdev = container_of(
245 		work, struct smc_ib_device, port_event_work);
246 	u8 port_idx;
247 
248 	for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
249 		smc_ib_remember_port_attr(smcibdev, port_idx + 1);
250 		clear_bit(port_idx, &smcibdev->port_event_mask);
251 		if (!smc_ib_port_active(smcibdev, port_idx + 1)) {
252 			set_bit(port_idx, smcibdev->ports_going_away);
253 			smcr_port_err(smcibdev, port_idx + 1);
254 		} else {
255 			clear_bit(port_idx, smcibdev->ports_going_away);
256 			smcr_port_add(smcibdev, port_idx + 1);
257 		}
258 	}
259 }
260 
261 /* can be called in IRQ context */
262 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
263 					struct ib_event *ibevent)
264 {
265 	struct smc_ib_device *smcibdev;
266 	bool schedule = false;
267 	u8 port_idx;
268 
269 	smcibdev = container_of(handler, struct smc_ib_device, event_handler);
270 
271 	switch (ibevent->event) {
272 	case IB_EVENT_DEVICE_FATAL:
273 		/* terminate all ports on device */
274 		for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++) {
275 			set_bit(port_idx, &smcibdev->port_event_mask);
276 			if (!test_and_set_bit(port_idx,
277 					      smcibdev->ports_going_away))
278 				schedule = true;
279 		}
280 		if (schedule)
281 			schedule_work(&smcibdev->port_event_work);
282 		break;
283 	case IB_EVENT_PORT_ACTIVE:
284 		port_idx = ibevent->element.port_num - 1;
285 		if (port_idx >= SMC_MAX_PORTS)
286 			break;
287 		set_bit(port_idx, &smcibdev->port_event_mask);
288 		if (test_and_clear_bit(port_idx, smcibdev->ports_going_away))
289 			schedule_work(&smcibdev->port_event_work);
290 		break;
291 	case IB_EVENT_PORT_ERR:
292 		port_idx = ibevent->element.port_num - 1;
293 		if (port_idx >= SMC_MAX_PORTS)
294 			break;
295 		set_bit(port_idx, &smcibdev->port_event_mask);
296 		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
297 			schedule_work(&smcibdev->port_event_work);
298 		break;
299 	case IB_EVENT_GID_CHANGE:
300 		port_idx = ibevent->element.port_num - 1;
301 		if (port_idx >= SMC_MAX_PORTS)
302 			break;
303 		set_bit(port_idx, &smcibdev->port_event_mask);
304 		schedule_work(&smcibdev->port_event_work);
305 		break;
306 	default:
307 		break;
308 	}
309 }
310 
311 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
312 {
313 	if (lnk->roce_pd)
314 		ib_dealloc_pd(lnk->roce_pd);
315 	lnk->roce_pd = NULL;
316 }
317 
318 int smc_ib_create_protection_domain(struct smc_link *lnk)
319 {
320 	int rc;
321 
322 	lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
323 	rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
324 	if (IS_ERR(lnk->roce_pd))
325 		lnk->roce_pd = NULL;
326 	return rc;
327 }
328 
329 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
330 {
331 	struct smc_link *lnk = (struct smc_link *)priv;
332 	struct smc_ib_device *smcibdev = lnk->smcibdev;
333 	u8 port_idx;
334 
335 	switch (ibevent->event) {
336 	case IB_EVENT_QP_FATAL:
337 	case IB_EVENT_QP_ACCESS_ERR:
338 		port_idx = ibevent->element.qp->port - 1;
339 		if (port_idx >= SMC_MAX_PORTS)
340 			break;
341 		set_bit(port_idx, &smcibdev->port_event_mask);
342 		if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
343 			schedule_work(&smcibdev->port_event_work);
344 		break;
345 	default:
346 		break;
347 	}
348 }
349 
350 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
351 {
352 	if (lnk->roce_qp)
353 		ib_destroy_qp(lnk->roce_qp);
354 	lnk->roce_qp = NULL;
355 }
356 
357 /* create a queue pair within the protection domain for a link */
358 int smc_ib_create_queue_pair(struct smc_link *lnk)
359 {
360 	struct ib_qp_init_attr qp_attr = {
361 		.event_handler = smc_ib_qp_event_handler,
362 		.qp_context = lnk,
363 		.send_cq = lnk->smcibdev->roce_cq_send,
364 		.recv_cq = lnk->smcibdev->roce_cq_recv,
365 		.srq = NULL,
366 		.cap = {
367 				/* include unsolicited rdma_writes as well,
368 				 * there are max. 2 RDMA_WRITE per 1 WR_SEND
369 				 */
370 			.max_send_wr = SMC_WR_BUF_CNT * 3,
371 			.max_recv_wr = SMC_WR_BUF_CNT * 3,
372 			.max_send_sge = SMC_IB_MAX_SEND_SGE,
373 			.max_recv_sge = 1,
374 		},
375 		.sq_sig_type = IB_SIGNAL_REQ_WR,
376 		.qp_type = IB_QPT_RC,
377 	};
378 	int rc;
379 
380 	lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
381 	rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
382 	if (IS_ERR(lnk->roce_qp))
383 		lnk->roce_qp = NULL;
384 	else
385 		smc_wr_remember_qp_attr(lnk);
386 	return rc;
387 }
388 
389 void smc_ib_put_memory_region(struct ib_mr *mr)
390 {
391 	ib_dereg_mr(mr);
392 }
393 
394 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot, u8 link_idx)
395 {
396 	unsigned int offset = 0;
397 	int sg_num;
398 
399 	/* map the largest prefix of a dma mapped SG list */
400 	sg_num = ib_map_mr_sg(buf_slot->mr_rx[link_idx],
401 			      buf_slot->sgt[link_idx].sgl,
402 			      buf_slot->sgt[link_idx].orig_nents,
403 			      &offset, PAGE_SIZE);
404 
405 	return sg_num;
406 }
407 
408 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
409 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
410 			     struct smc_buf_desc *buf_slot, u8 link_idx)
411 {
412 	if (buf_slot->mr_rx[link_idx])
413 		return 0; /* already done */
414 
415 	buf_slot->mr_rx[link_idx] =
416 		ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
417 	if (IS_ERR(buf_slot->mr_rx[link_idx])) {
418 		int rc;
419 
420 		rc = PTR_ERR(buf_slot->mr_rx[link_idx]);
421 		buf_slot->mr_rx[link_idx] = NULL;
422 		return rc;
423 	}
424 
425 	if (smc_ib_map_mr_sg(buf_slot, link_idx) != 1)
426 		return -EINVAL;
427 
428 	return 0;
429 }
430 
431 /* synchronize buffer usage for cpu access */
432 void smc_ib_sync_sg_for_cpu(struct smc_link *lnk,
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[lnk->link_idx].sgl, sg,
441 		    buf_slot->sgt[lnk->link_idx].nents, i) {
442 		if (!sg_dma_len(sg))
443 			break;
444 		ib_dma_sync_single_for_cpu(lnk->smcibdev->ibdev,
445 					   sg_dma_address(sg),
446 					   sg_dma_len(sg),
447 					   data_direction);
448 	}
449 }
450 
451 /* synchronize buffer usage for device access */
452 void smc_ib_sync_sg_for_device(struct smc_link *lnk,
453 			       struct smc_buf_desc *buf_slot,
454 			       enum dma_data_direction data_direction)
455 {
456 	struct scatterlist *sg;
457 	unsigned int i;
458 
459 	/* for now there is just one DMA address */
460 	for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg,
461 		    buf_slot->sgt[lnk->link_idx].nents, i) {
462 		if (!sg_dma_len(sg))
463 			break;
464 		ib_dma_sync_single_for_device(lnk->smcibdev->ibdev,
465 					      sg_dma_address(sg),
466 					      sg_dma_len(sg),
467 					      data_direction);
468 	}
469 }
470 
471 /* Map a new TX or RX buffer SG-table to DMA */
472 int smc_ib_buf_map_sg(struct smc_link *lnk,
473 		      struct smc_buf_desc *buf_slot,
474 		      enum dma_data_direction data_direction)
475 {
476 	int mapped_nents;
477 
478 	mapped_nents = ib_dma_map_sg(lnk->smcibdev->ibdev,
479 				     buf_slot->sgt[lnk->link_idx].sgl,
480 				     buf_slot->sgt[lnk->link_idx].orig_nents,
481 				     data_direction);
482 	if (!mapped_nents)
483 		return -ENOMEM;
484 
485 	return mapped_nents;
486 }
487 
488 void smc_ib_buf_unmap_sg(struct smc_link *lnk,
489 			 struct smc_buf_desc *buf_slot,
490 			 enum dma_data_direction data_direction)
491 {
492 	if (!buf_slot->sgt[lnk->link_idx].sgl->dma_address)
493 		return; /* already unmapped */
494 
495 	ib_dma_unmap_sg(lnk->smcibdev->ibdev,
496 			buf_slot->sgt[lnk->link_idx].sgl,
497 			buf_slot->sgt[lnk->link_idx].orig_nents,
498 			data_direction);
499 	buf_slot->sgt[lnk->link_idx].sgl->dma_address = 0;
500 }
501 
502 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
503 {
504 	struct ib_cq_init_attr cqattr =	{
505 		.cqe = SMC_MAX_CQE, .comp_vector = 0 };
506 	int cqe_size_order, smc_order;
507 	long rc;
508 
509 	mutex_lock(&smcibdev->mutex);
510 	rc = 0;
511 	if (smcibdev->initialized)
512 		goto out;
513 	/* the calculated number of cq entries fits to mlx5 cq allocation */
514 	cqe_size_order = cache_line_size() == 128 ? 7 : 6;
515 	smc_order = MAX_ORDER - cqe_size_order - 1;
516 	if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
517 		cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
518 	smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
519 					      smc_wr_tx_cq_handler, NULL,
520 					      smcibdev, &cqattr);
521 	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
522 	if (IS_ERR(smcibdev->roce_cq_send)) {
523 		smcibdev->roce_cq_send = NULL;
524 		goto out;
525 	}
526 	smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
527 					      smc_wr_rx_cq_handler, NULL,
528 					      smcibdev, &cqattr);
529 	rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
530 	if (IS_ERR(smcibdev->roce_cq_recv)) {
531 		smcibdev->roce_cq_recv = NULL;
532 		goto err;
533 	}
534 	smc_wr_add_dev(smcibdev);
535 	smcibdev->initialized = 1;
536 	goto out;
537 
538 err:
539 	ib_destroy_cq(smcibdev->roce_cq_send);
540 out:
541 	mutex_unlock(&smcibdev->mutex);
542 	return rc;
543 }
544 
545 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
546 {
547 	mutex_lock(&smcibdev->mutex);
548 	if (!smcibdev->initialized)
549 		goto out;
550 	smcibdev->initialized = 0;
551 	ib_destroy_cq(smcibdev->roce_cq_recv);
552 	ib_destroy_cq(smcibdev->roce_cq_send);
553 	smc_wr_remove_dev(smcibdev);
554 out:
555 	mutex_unlock(&smcibdev->mutex);
556 }
557 
558 static struct ib_client smc_ib_client;
559 
560 /* callback function for ib_register_client() */
561 static int smc_ib_add_dev(struct ib_device *ibdev)
562 {
563 	struct smc_ib_device *smcibdev;
564 	u8 port_cnt;
565 	int i;
566 
567 	if (ibdev->node_type != RDMA_NODE_IB_CA)
568 		return -EOPNOTSUPP;
569 
570 	smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
571 	if (!smcibdev)
572 		return -ENOMEM;
573 
574 	smcibdev->ibdev = ibdev;
575 	INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
576 	atomic_set(&smcibdev->lnk_cnt, 0);
577 	init_waitqueue_head(&smcibdev->lnks_deleted);
578 	mutex_init(&smcibdev->mutex);
579 	mutex_lock(&smc_ib_devices.mutex);
580 	list_add_tail(&smcibdev->list, &smc_ib_devices.list);
581 	mutex_unlock(&smc_ib_devices.mutex);
582 	ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
583 	INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
584 			      smc_ib_global_event_handler);
585 	ib_register_event_handler(&smcibdev->event_handler);
586 
587 	/* trigger reading of the port attributes */
588 	port_cnt = smcibdev->ibdev->phys_port_cnt;
589 	pr_warn_ratelimited("smc: adding ib device %s with port count %d\n",
590 			    smcibdev->ibdev->name, port_cnt);
591 	for (i = 0;
592 	     i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
593 	     i++) {
594 		set_bit(i, &smcibdev->port_event_mask);
595 		/* determine pnetids of the port */
596 		if (smc_pnetid_by_dev_port(ibdev->dev.parent, i,
597 					   smcibdev->pnetid[i]))
598 			smc_pnetid_by_table_ib(smcibdev, i + 1);
599 		pr_warn_ratelimited("smc:    ib device %s port %d has pnetid "
600 				    "%.16s%s\n",
601 				    smcibdev->ibdev->name, i + 1,
602 				    smcibdev->pnetid[i],
603 				    smcibdev->pnetid_by_user[i] ?
604 				     " (user defined)" :
605 				     "");
606 	}
607 	schedule_work(&smcibdev->port_event_work);
608 	return 0;
609 }
610 
611 /* callback function for ib_unregister_client() */
612 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
613 {
614 	struct smc_ib_device *smcibdev = client_data;
615 
616 	mutex_lock(&smc_ib_devices.mutex);
617 	list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
618 	mutex_unlock(&smc_ib_devices.mutex);
619 	pr_warn_ratelimited("smc: removing ib device %s\n",
620 			    smcibdev->ibdev->name);
621 	smc_smcr_terminate_all(smcibdev);
622 	smc_ib_cleanup_per_ibdev(smcibdev);
623 	ib_unregister_event_handler(&smcibdev->event_handler);
624 	cancel_work_sync(&smcibdev->port_event_work);
625 	kfree(smcibdev);
626 }
627 
628 static struct ib_client smc_ib_client = {
629 	.name	= "smc_ib",
630 	.add	= smc_ib_add_dev,
631 	.remove = smc_ib_remove_dev,
632 };
633 
634 int __init smc_ib_register_client(void)
635 {
636 	smc_ib_init_local_systemid();
637 	return ib_register_client(&smc_ib_client);
638 }
639 
640 void smc_ib_unregister_client(void)
641 {
642 	ib_unregister_client(&smc_ib_client);
643 }
644