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