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         struct ib_gid_attr gattr;
 149         union ib_gid gid;
 150         int rc;
 151
 152         rc = ib_query_gid(smcibdev->ibdev, ibport, 0, &gid, &gattr);
 153         if (rc || !gattr.ndev)
 154                 return -ENODEV;
 155
 156         memcpy(smcibdev->mac[ibport - 1], gattr.ndev->dev_addr, ETH_ALEN);
 157         dev_put(gattr.ndev);
 158         return 0;
 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         struct ib_gid_attr gattr;
 184         union ib_gid _gid;
 185         int i;
 186
 187         for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
 188                 memset(&_gid, 0, SMC_GID_SIZE);
 189                 memset(&gattr, 0, sizeof(gattr));
 190                 if (ib_query_gid(smcibdev->ibdev, ibport, i, &_gid, &gattr))
 191                         continue;
 192                 if (!gattr.ndev)
 193                         continue;
 194                 if (((!vlan_id && !is_vlan_dev(gattr.ndev)) ||
 195                      (vlan_id && is_vlan_dev(gattr.ndev) &&
 196                       vlan_dev_vlan_id(gattr.ndev) == vlan_id)) &&
 197                     gattr.gid_type == IB_GID_TYPE_IB) {
 198                         if (gid)
 199                                 memcpy(gid, &_gid, SMC_GID_SIZE);
 200                         if (sgid_index)
 201                                 *sgid_index = i;
 202                         dev_put(gattr.ndev);
 203                         return 0;
 204                 }
 205                 dev_put(gattr.ndev);
 206         }
 207         return -ENODEV;
 208 }
 209
 210 static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 211 {
 212         int rc;
 213
 214         memset(&smcibdev->pattr[ibport - 1], 0,
 215                sizeof(smcibdev->pattr[ibport - 1]));
 216         rc = ib_query_port(smcibdev->ibdev, ibport,
 217                            &smcibdev->pattr[ibport - 1]);
 218         if (rc)
 219                 goto out;
 220         /* the SMC protocol requires specification of the RoCE MAC address */
 221         rc = smc_ib_fill_mac(smcibdev, ibport);
 222         if (rc)
 223                 goto out;
 224         if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
 225                      sizeof(local_systemid)) &&
 226             smc_ib_port_active(smcibdev, ibport))
 227                 /* create unique system identifier */
 228                 smc_ib_define_local_systemid(smcibdev, ibport);
 229 out:
 230         return rc;
 231 }
 232
 233 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
 234 static void smc_ib_port_event_work(struct work_struct *work)
 235 {
 236         struct smc_ib_device *smcibdev = container_of(
 237                 work, struct smc_ib_device, port_event_work);
 238         u8 port_idx;
 239
 240         for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
 241                 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
 242                 clear_bit(port_idx, &smcibdev->port_event_mask);
 243                 if (!smc_ib_port_active(smcibdev, port_idx + 1))
 244                         smc_port_terminate(smcibdev, port_idx + 1);
 245         }
 246 }
 247
 248 /* can be called in IRQ context */
 249 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 250                                         struct ib_event *ibevent)
 251 {
 252         struct smc_ib_device *smcibdev;
 253         u8 port_idx;
 254
 255         smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 256
 257         switch (ibevent->event) {
 258         case IB_EVENT_PORT_ERR:
 259         case IB_EVENT_DEVICE_FATAL:
 260         case IB_EVENT_PORT_ACTIVE:
 261                 port_idx = ibevent->element.port_num - 1;
 262                 set_bit(port_idx, &smcibdev->port_event_mask);
 263                 schedule_work(&smcibdev->port_event_work);
 264                 break;
 265         default:
 266                 break;
 267         }
 268 }
 269
 270 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
 271 {
 272         if (lnk->roce_pd)
 273                 ib_dealloc_pd(lnk->roce_pd);
 274         lnk->roce_pd = NULL;
 275 }
 276
 277 int smc_ib_create_protection_domain(struct smc_link *lnk)
 278 {
 279         int rc;
 280
 281         lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
 282         rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
 283         if (IS_ERR(lnk->roce_pd))
 284                 lnk->roce_pd = NULL;
 285         return rc;
 286 }
 287
 288 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 289 {
 290         struct smc_ib_device *smcibdev =
 291                 (struct smc_ib_device *)ibevent->device;
 292         u8 port_idx;
 293
 294         switch (ibevent->event) {
 295         case IB_EVENT_DEVICE_FATAL:
 296         case IB_EVENT_GID_CHANGE:
 297         case IB_EVENT_PORT_ERR:
 298         case IB_EVENT_QP_ACCESS_ERR:
 299                 port_idx = ibevent->element.port_num - 1;
 300                 set_bit(port_idx, &smcibdev->port_event_mask);
 301                 schedule_work(&smcibdev->port_event_work);
 302                 break;
 303         default:
 304                 break;
 305         }
 306 }
 307
 308 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
 309 {
 310         if (lnk->roce_qp)
 311                 ib_destroy_qp(lnk->roce_qp);
 312         lnk->roce_qp = NULL;
 313 }
 314
 315 /* create a queue pair within the protection domain for a link */
 316 int smc_ib_create_queue_pair(struct smc_link *lnk)
 317 {
 318         struct ib_qp_init_attr qp_attr = {
 319                 .event_handler = smc_ib_qp_event_handler,
 320                 .qp_context = lnk,
 321                 .send_cq = lnk->smcibdev->roce_cq_send,
 322                 .recv_cq = lnk->smcibdev->roce_cq_recv,
 323                 .srq = NULL,
 324                 .cap = {
 325                                 /* include unsolicited rdma_writes as well,
 326                                  * there are max. 2 RDMA_WRITE per 1 WR_SEND
 327                                  */
 328                         .max_send_wr = SMC_WR_BUF_CNT * 3,
 329                         .max_recv_wr = SMC_WR_BUF_CNT * 3,
 330                         .max_send_sge = SMC_IB_MAX_SEND_SGE,
 331                         .max_recv_sge = 1,
 332                 },
 333                 .sq_sig_type = IB_SIGNAL_REQ_WR,
 334                 .qp_type = IB_QPT_RC,
 335         };
 336         int rc;
 337
 338         lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
 339         rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
 340         if (IS_ERR(lnk->roce_qp))
 341                 lnk->roce_qp = NULL;
 342         else
 343                 smc_wr_remember_qp_attr(lnk);
 344         return rc;
 345 }
 346
 347 void smc_ib_put_memory_region(struct ib_mr *mr)
 348 {
 349         ib_dereg_mr(mr);
 350 }
 351
 352 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
 353 {
 354         unsigned int offset = 0;
 355         int sg_num;
 356
 357         /* map the largest prefix of a dma mapped SG list */
 358         sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
 359                               buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 360                               buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 361                               &offset, PAGE_SIZE);
 362
 363         return sg_num;
 364 }
 365
 366 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
 367 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 368                              struct smc_buf_desc *buf_slot)
 369 {
 370         if (buf_slot->mr_rx[SMC_SINGLE_LINK])
 371                 return 0; /* already done */
 372
 373         buf_slot->mr_rx[SMC_SINGLE_LINK] =
 374                 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
 375         if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
 376                 int rc;
 377
 378                 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
 379                 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
 380                 return rc;
 381         }
 382
 383         if (smc_ib_map_mr_sg(buf_slot) != 1)
 384                 return -EINVAL;
 385
 386         return 0;
 387 }
 388
 389 /* synchronize buffer usage for cpu access */
 390 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
 391                             struct smc_buf_desc *buf_slot,
 392                             enum dma_data_direction data_direction)
 393 {
 394         struct scatterlist *sg;
 395         unsigned int i;
 396
 397         /* for now there is just one DMA address */
 398         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 399                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 400                 if (!sg_dma_len(sg))
 401                         break;
 402                 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
 403                                            sg_dma_address(sg),
 404                                            sg_dma_len(sg),
 405                                            data_direction);
 406         }
 407 }
 408
 409 /* synchronize buffer usage for device access */
 410 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
 411                                struct smc_buf_desc *buf_slot,
 412                                enum dma_data_direction data_direction)
 413 {
 414         struct scatterlist *sg;
 415         unsigned int i;
 416
 417         /* for now there is just one DMA address */
 418         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 419                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 420                 if (!sg_dma_len(sg))
 421                         break;
 422                 ib_dma_sync_single_for_device(smcibdev->ibdev,
 423                                               sg_dma_address(sg),
 424                                               sg_dma_len(sg),
 425                                               data_direction);
 426         }
 427 }
 428
 429 /* Map a new TX or RX buffer SG-table to DMA */
 430 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
 431                       struct smc_buf_desc *buf_slot,
 432                       enum dma_data_direction data_direction)
 433 {
 434         int mapped_nents;
 435
 436         mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
 437                                      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 438                                      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 439                                      data_direction);
 440         if (!mapped_nents)
 441                 return -ENOMEM;
 442
 443         return mapped_nents;
 444 }
 445
 446 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
 447                          struct smc_buf_desc *buf_slot,
 448                          enum dma_data_direction data_direction)
 449 {
 450         if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
 451                 return; /* already unmapped */
 452
 453         ib_dma_unmap_sg(smcibdev->ibdev,
 454                         buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 455                         buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 456                         data_direction);
 457         buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
 458 }
 459
 460 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
 461 {
 462         struct ib_cq_init_attr cqattr = {
 463                 .cqe = SMC_MAX_CQE, .comp_vector = 0 };
 464         int cqe_size_order, smc_order;
 465         long rc;
 466
 467         /* the calculated number of cq entries fits to mlx5 cq allocation */
 468         cqe_size_order = cache_line_size() == 128 ? 7 : 6;
 469         smc_order = MAX_ORDER - cqe_size_order - 1;
 470         if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
 471                 cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
 472         smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
 473                                               smc_wr_tx_cq_handler, NULL,
 474                                               smcibdev, &cqattr);
 475         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
 476         if (IS_ERR(smcibdev->roce_cq_send)) {
 477                 smcibdev->roce_cq_send = NULL;
 478                 return rc;
 479         }
 480         smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
 481                                               smc_wr_rx_cq_handler, NULL,
 482                                               smcibdev, &cqattr);
 483         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
 484         if (IS_ERR(smcibdev->roce_cq_recv)) {
 485                 smcibdev->roce_cq_recv = NULL;
 486                 goto err;
 487         }
 488         smc_wr_add_dev(smcibdev);
 489         smcibdev->initialized = 1;
 490         return rc;
 491
 492 err:
 493         ib_destroy_cq(smcibdev->roce_cq_send);
 494         return rc;
 495 }
 496
 497 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 498 {
 499         if (!smcibdev->initialized)
 500                 return;
 501         smcibdev->initialized = 0;
 502         smc_wr_remove_dev(smcibdev);
 503         ib_destroy_cq(smcibdev->roce_cq_recv);
 504         ib_destroy_cq(smcibdev->roce_cq_send);
 505 }
 506
 507 static struct ib_client smc_ib_client;
 508
 509 /* callback function for ib_register_client() */
 510 static void smc_ib_add_dev(struct ib_device *ibdev)
 511 {
 512         struct smc_ib_device *smcibdev;
 513         u8 port_cnt;
 514         int i;
 515
 516         if (ibdev->node_type != RDMA_NODE_IB_CA)
 517                 return;
 518
 519         smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
 520         if (!smcibdev)
 521                 return;
 522
 523         smcibdev->ibdev = ibdev;
 524         INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 525
 526         spin_lock(&smc_ib_devices.lock);
 527         list_add_tail(&smcibdev->list, &smc_ib_devices.list);
 528         spin_unlock(&smc_ib_devices.lock);
 529         ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 530         INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 531                               smc_ib_global_event_handler);
 532         ib_register_event_handler(&smcibdev->event_handler);
 533
 534         /* trigger reading of the port attributes */
 535         port_cnt = smcibdev->ibdev->phys_port_cnt;
 536         for (i = 0;
 537              i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
 538              i++) {
 539                 set_bit(i, &smcibdev->port_event_mask);
 540                 /* determine pnetids of the port */
 541                 smc_pnetid_by_dev_port(ibdev->dev.parent, i,
 542                                        smcibdev->pnetid[i]);
 543         }
 544         schedule_work(&smcibdev->port_event_work);
 545 }
 546
 547 /* callback function for ib_register_client() */
 548 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 549 {
 550         struct smc_ib_device *smcibdev;
 551
 552         smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
 553         ib_set_client_data(ibdev, &smc_ib_client, NULL);
 554         spin_lock(&smc_ib_devices.lock);
 555         list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
 556         spin_unlock(&smc_ib_devices.lock);
 557         smc_pnet_remove_by_ibdev(smcibdev);
 558         smc_ib_cleanup_per_ibdev(smcibdev);
 559         ib_unregister_event_handler(&smcibdev->event_handler);
 560         kfree(smcibdev);
 561 }
 562
 563 static struct ib_client smc_ib_client = {
 564         .name   = "smc_ib",
 565         .add    = smc_ib_add_dev,
 566         .remove = smc_ib_remove_dev,
 567 };
 568
 569 int __init smc_ib_register_client(void)
 570 {
 571         return ib_register_client(&smc_ib_client);
 572 }
 573
 574 void smc_ib_unregister_client(void)
 575 {
 576         ib_unregister_client(&smc_ib_client);
 577 }