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 <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 u8 local_systemid[SMC_SYSTEMID_LEN];            /* unique system identifier */
  41
  42 static int smc_ib_modify_qp_init(struct smc_link *lnk)
  43 {
  44         struct ib_qp_attr qp_attr;
  45
  46         memset(&qp_attr, 0, sizeof(qp_attr));
  47         qp_attr.qp_state = IB_QPS_INIT;
  48         qp_attr.pkey_index = 0;
  49         qp_attr.port_num = lnk->ibport;
  50         qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
  51                                 | IB_ACCESS_REMOTE_WRITE;
  52         return ib_modify_qp(lnk->roce_qp, &qp_attr,
  53                             IB_QP_STATE | IB_QP_PKEY_INDEX |
  54                             IB_QP_ACCESS_FLAGS | IB_QP_PORT);
  55 }
  56
  57 static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
  58 {
  59         enum ib_qp_attr_mask qp_attr_mask =
  60                 IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
  61                 IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
  62         struct ib_qp_attr qp_attr;
  63
  64         memset(&qp_attr, 0, sizeof(qp_attr));
  65         qp_attr.qp_state = IB_QPS_RTR;
  66         qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
  67         qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
  68         rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
  69         rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, lnk->sgid_index, 1, 0);
  70         rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
  71         memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
  72                sizeof(lnk->peer_mac));
  73         qp_attr.dest_qp_num = lnk->peer_qpn;
  74         qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
  75         qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
  76                                          * requests
  77                                          */
  78         qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
  79
  80         return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
  81 }
  82
  83 int smc_ib_modify_qp_rts(struct smc_link *lnk)
  84 {
  85         struct ib_qp_attr qp_attr;
  86
  87         memset(&qp_attr, 0, sizeof(qp_attr));
  88         qp_attr.qp_state = IB_QPS_RTS;
  89         qp_attr.timeout = SMC_QP_TIMEOUT;       /* local ack timeout */
  90         qp_attr.retry_cnt = SMC_QP_RETRY_CNT;   /* retry count */
  91         qp_attr.rnr_retry = SMC_QP_RNR_RETRY;   /* RNR retries, 7=infinite */
  92         qp_attr.sq_psn = lnk->psn_initial;      /* starting send packet seq # */
  93         qp_attr.max_rd_atomic = 1;      /* # of outstanding RDMA reads and
  94                                          * atomic ops allowed
  95                                          */
  96         return ib_modify_qp(lnk->roce_qp, &qp_attr,
  97                             IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
  98                             IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
  99                             IB_QP_MAX_QP_RD_ATOMIC);
 100 }
 101
 102 int smc_ib_modify_qp_reset(struct smc_link *lnk)
 103 {
 104         struct ib_qp_attr qp_attr;
 105
 106         memset(&qp_attr, 0, sizeof(qp_attr));
 107         qp_attr.qp_state = IB_QPS_RESET;
 108         return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
 109 }
 110
 111 int smc_ib_ready_link(struct smc_link *lnk)
 112 {
 113         struct smc_link_group *lgr = smc_get_lgr(lnk);
 114         int rc = 0;
 115
 116         rc = smc_ib_modify_qp_init(lnk);
 117         if (rc)
 118                 goto out;
 119
 120         rc = smc_ib_modify_qp_rtr(lnk);
 121         if (rc)
 122                 goto out;
 123         smc_wr_remember_qp_attr(lnk);
 124         rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
 125                               IB_CQ_SOLICITED_MASK);
 126         if (rc)
 127                 goto out;
 128         rc = smc_wr_rx_post_init(lnk);
 129         if (rc)
 130                 goto out;
 131         smc_wr_remember_qp_attr(lnk);
 132
 133         if (lgr->role == SMC_SERV) {
 134                 rc = smc_ib_modify_qp_rts(lnk);
 135                 if (rc)
 136                         goto out;
 137                 smc_wr_remember_qp_attr(lnk);
 138         }
 139 out:
 140         return rc;
 141 }
 142
 143 static int smc_ib_fill_mac(struct smc_ib_device *smcibdev, u8 ibport)
 144 {
 145         const struct ib_gid_attr *attr;
 146         int rc;
 147
 148         attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, 0);
 149         if (IS_ERR(attr))
 150                 return -ENODEV;
 151
 152         rc = rdma_read_gid_l2_fields(attr, NULL, smcibdev->mac[ibport - 1]);
 153         rdma_put_gid_attr(attr);
 154         return rc;
 155 }
 156
 157 /* Create an identifier unique for this instance of SMC-R.
 158  * The MAC-address of the first active registered IB device
 159  * plus a random 2-byte number is used to create this identifier.
 160  * This name is delivered to the peer during connection initialization.
 161  */
 162 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
 163                                                 u8 ibport)
 164 {
 165         memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
 166                sizeof(smcibdev->mac[ibport - 1]));
 167 }
 168
 169 bool smc_ib_is_valid_local_systemid(void)
 170 {
 171         return !is_zero_ether_addr(&local_systemid[2]);
 172 }
 173
 174 static void smc_ib_init_local_systemid(void)
 175 {
 176         get_random_bytes(&local_systemid[0], 2);
 177 }
 178
 179 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
 180 {
 181         return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
 182 }
 183
 184 /* determine the gid for an ib-device port and vlan id */
 185 int smc_ib_determine_gid(struct smc_ib_device *smcibdev, u8 ibport,
 186                          unsigned short vlan_id, u8 gid[], u8 *sgid_index)
 187 {
 188         const struct ib_gid_attr *attr;
 189         const struct net_device *ndev;
 190         int i;
 191
 192         for (i = 0; i < smcibdev->pattr[ibport - 1].gid_tbl_len; i++) {
 193                 attr = rdma_get_gid_attr(smcibdev->ibdev, ibport, i);
 194                 if (IS_ERR(attr))
 195                         continue;
 196
 197                 rcu_read_lock();
 198                 ndev = rdma_read_gid_attr_ndev_rcu(attr);
 199                 if (!IS_ERR(ndev) &&
 200                     ((!vlan_id && !is_vlan_dev(attr->ndev)) ||
 201                      (vlan_id && is_vlan_dev(attr->ndev) &&
 202                       vlan_dev_vlan_id(attr->ndev) == vlan_id)) &&
 203                     attr->gid_type == IB_GID_TYPE_ROCE) {
 204                         rcu_read_unlock();
 205                         if (gid)
 206                                 memcpy(gid, &attr->gid, SMC_GID_SIZE);
 207                         if (sgid_index)
 208                                 *sgid_index = attr->index;
 209                         rdma_put_gid_attr(attr);
 210                         return 0;
 211                 }
 212                 rcu_read_unlock();
 213                 rdma_put_gid_attr(attr);
 214         }
 215         return -ENODEV;
 216 }
 217
 218 static int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 219 {
 220         int rc;
 221
 222         memset(&smcibdev->pattr[ibport - 1], 0,
 223                sizeof(smcibdev->pattr[ibport - 1]));
 224         rc = ib_query_port(smcibdev->ibdev, ibport,
 225                            &smcibdev->pattr[ibport - 1]);
 226         if (rc)
 227                 goto out;
 228         /* the SMC protocol requires specification of the RoCE MAC address */
 229         rc = smc_ib_fill_mac(smcibdev, ibport);
 230         if (rc)
 231                 goto out;
 232         if (!smc_ib_is_valid_local_systemid() &&
 233             smc_ib_port_active(smcibdev, ibport))
 234                 /* create unique system identifier */
 235                 smc_ib_define_local_systemid(smcibdev, ibport);
 236 out:
 237         return rc;
 238 }
 239
 240 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
 241 static void smc_ib_port_event_work(struct work_struct *work)
 242 {
 243         struct smc_ib_device *smcibdev = container_of(
 244                 work, struct smc_ib_device, port_event_work);
 245         u8 port_idx;
 246
 247         for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
 248                 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
 249                 clear_bit(port_idx, &smcibdev->port_event_mask);
 250                 if (!smc_ib_port_active(smcibdev, port_idx + 1)) {
 251                         set_bit(port_idx, smcibdev->ports_going_away);
 252                         smc_port_terminate(smcibdev, port_idx + 1);
 253                 } else {
 254                         clear_bit(port_idx, smcibdev->ports_going_away);
 255                 }
 256         }
 257 }
 258
 259 /* can be called in IRQ context */
 260 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 261                                         struct ib_event *ibevent)
 262 {
 263         struct smc_ib_device *smcibdev;
 264         bool schedule = false;
 265         u8 port_idx;
 266
 267         smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 268
 269         switch (ibevent->event) {
 270         case IB_EVENT_DEVICE_FATAL:
 271                 /* terminate all ports on device */
 272                 for (port_idx = 0; port_idx < SMC_MAX_PORTS; port_idx++) {
 273                         set_bit(port_idx, &smcibdev->port_event_mask);
 274                         if (!test_and_set_bit(port_idx,
 275                                               smcibdev->ports_going_away))
 276                                 schedule = true;
 277                 }
 278                 if (schedule)
 279                         schedule_work(&smcibdev->port_event_work);
 280                 break;
 281         case IB_EVENT_PORT_ACTIVE:
 282                 port_idx = ibevent->element.port_num - 1;
 283                 if (port_idx >= SMC_MAX_PORTS)
 284                         break;
 285                 set_bit(port_idx, &smcibdev->port_event_mask);
 286                 if (test_and_clear_bit(port_idx, smcibdev->ports_going_away))
 287                         schedule_work(&smcibdev->port_event_work);
 288                 break;
 289         case IB_EVENT_PORT_ERR:
 290                 port_idx = ibevent->element.port_num - 1;
 291                 if (port_idx >= SMC_MAX_PORTS)
 292                         break;
 293                 set_bit(port_idx, &smcibdev->port_event_mask);
 294                 if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
 295                         schedule_work(&smcibdev->port_event_work);
 296                 break;
 297         case IB_EVENT_GID_CHANGE:
 298                 port_idx = ibevent->element.port_num - 1;
 299                 if (port_idx >= SMC_MAX_PORTS)
 300                         break;
 301                 set_bit(port_idx, &smcibdev->port_event_mask);
 302                 schedule_work(&smcibdev->port_event_work);
 303                 break;
 304         default:
 305                 break;
 306         }
 307 }
 308
 309 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
 310 {
 311         if (lnk->roce_pd)
 312                 ib_dealloc_pd(lnk->roce_pd);
 313         lnk->roce_pd = NULL;
 314 }
 315
 316 int smc_ib_create_protection_domain(struct smc_link *lnk)
 317 {
 318         int rc;
 319
 320         lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
 321         rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
 322         if (IS_ERR(lnk->roce_pd))
 323                 lnk->roce_pd = NULL;
 324         return rc;
 325 }
 326
 327 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 328 {
 329         struct smc_link *lnk = (struct smc_link *)priv;
 330         struct smc_ib_device *smcibdev = lnk->smcibdev;
 331         u8 port_idx;
 332
 333         switch (ibevent->event) {
 334         case IB_EVENT_QP_FATAL:
 335         case IB_EVENT_QP_ACCESS_ERR:
 336                 port_idx = ibevent->element.qp->port - 1;
 337                 if (port_idx >= SMC_MAX_PORTS)
 338                         break;
 339                 set_bit(port_idx, &smcibdev->port_event_mask);
 340                 if (!test_and_set_bit(port_idx, smcibdev->ports_going_away))
 341                         schedule_work(&smcibdev->port_event_work);
 342                 break;
 343         default:
 344                 break;
 345         }
 346 }
 347
 348 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
 349 {
 350         if (lnk->roce_qp)
 351                 ib_destroy_qp(lnk->roce_qp);
 352         lnk->roce_qp = NULL;
 353 }
 354
 355 /* create a queue pair within the protection domain for a link */
 356 int smc_ib_create_queue_pair(struct smc_link *lnk)
 357 {
 358         struct ib_qp_init_attr qp_attr = {
 359                 .event_handler = smc_ib_qp_event_handler,
 360                 .qp_context = lnk,
 361                 .send_cq = lnk->smcibdev->roce_cq_send,
 362                 .recv_cq = lnk->smcibdev->roce_cq_recv,
 363                 .srq = NULL,
 364                 .cap = {
 365                                 /* include unsolicited rdma_writes as well,
 366                                  * there are max. 2 RDMA_WRITE per 1 WR_SEND
 367                                  */
 368                         .max_send_wr = SMC_WR_BUF_CNT * 3,
 369                         .max_recv_wr = SMC_WR_BUF_CNT * 3,
 370                         .max_send_sge = SMC_IB_MAX_SEND_SGE,
 371                         .max_recv_sge = 1,
 372                 },
 373                 .sq_sig_type = IB_SIGNAL_REQ_WR,
 374                 .qp_type = IB_QPT_RC,
 375         };
 376         int rc;
 377
 378         lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
 379         rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
 380         if (IS_ERR(lnk->roce_qp))
 381                 lnk->roce_qp = NULL;
 382         else
 383                 smc_wr_remember_qp_attr(lnk);
 384         return rc;
 385 }
 386
 387 void smc_ib_put_memory_region(struct ib_mr *mr)
 388 {
 389         ib_dereg_mr(mr);
 390 }
 391
 392 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
 393 {
 394         unsigned int offset = 0;
 395         int sg_num;
 396
 397         /* map the largest prefix of a dma mapped SG list */
 398         sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
 399                               buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 400                               buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 401                               &offset, PAGE_SIZE);
 402
 403         return sg_num;
 404 }
 405
 406 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
 407 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 408                              struct smc_buf_desc *buf_slot)
 409 {
 410         if (buf_slot->mr_rx[SMC_SINGLE_LINK])
 411                 return 0; /* already done */
 412
 413         buf_slot->mr_rx[SMC_SINGLE_LINK] =
 414                 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
 415         if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
 416                 int rc;
 417
 418                 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
 419                 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
 420                 return rc;
 421         }
 422
 423         if (smc_ib_map_mr_sg(buf_slot) != 1)
 424                 return -EINVAL;
 425
 426         return 0;
 427 }
 428
 429 /* synchronize buffer usage for cpu access */
 430 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
 431                             struct smc_buf_desc *buf_slot,
 432                             enum dma_data_direction data_direction)
 433 {
 434         struct scatterlist *sg;
 435         unsigned int i;
 436
 437         /* for now there is just one DMA address */
 438         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 439                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 440                 if (!sg_dma_len(sg))
 441                         break;
 442                 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
 443                                            sg_dma_address(sg),
 444                                            sg_dma_len(sg),
 445                                            data_direction);
 446         }
 447 }
 448
 449 /* synchronize buffer usage for device access */
 450 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
 451                                struct smc_buf_desc *buf_slot,
 452                                enum dma_data_direction data_direction)
 453 {
 454         struct scatterlist *sg;
 455         unsigned int i;
 456
 457         /* for now there is just one DMA address */
 458         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 459                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 460                 if (!sg_dma_len(sg))
 461                         break;
 462                 ib_dma_sync_single_for_device(smcibdev->ibdev,
 463                                               sg_dma_address(sg),
 464                                               sg_dma_len(sg),
 465                                               data_direction);
 466         }
 467 }
 468
 469 /* Map a new TX or RX buffer SG-table to DMA */
 470 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
 471                       struct smc_buf_desc *buf_slot,
 472                       enum dma_data_direction data_direction)
 473 {
 474         int mapped_nents;
 475
 476         mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
 477                                      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 478                                      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 479                                      data_direction);
 480         if (!mapped_nents)
 481                 return -ENOMEM;
 482
 483         return mapped_nents;
 484 }
 485
 486 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
 487                          struct smc_buf_desc *buf_slot,
 488                          enum dma_data_direction data_direction)
 489 {
 490         if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
 491                 return; /* already unmapped */
 492
 493         ib_dma_unmap_sg(smcibdev->ibdev,
 494                         buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 495                         buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 496                         data_direction);
 497         buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
 498 }
 499
 500 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
 501 {
 502         struct ib_cq_init_attr cqattr = {
 503                 .cqe = SMC_MAX_CQE, .comp_vector = 0 };
 504         int cqe_size_order, smc_order;
 505         long rc;
 506
 507         /* the calculated number of cq entries fits to mlx5 cq allocation */
 508         cqe_size_order = cache_line_size() == 128 ? 7 : 6;
 509         smc_order = MAX_ORDER - cqe_size_order - 1;
 510         if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
 511                 cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
 512         smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
 513                                               smc_wr_tx_cq_handler, NULL,
 514                                               smcibdev, &cqattr);
 515         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
 516         if (IS_ERR(smcibdev->roce_cq_send)) {
 517                 smcibdev->roce_cq_send = NULL;
 518                 return rc;
 519         }
 520         smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
 521                                               smc_wr_rx_cq_handler, NULL,
 522                                               smcibdev, &cqattr);
 523         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
 524         if (IS_ERR(smcibdev->roce_cq_recv)) {
 525                 smcibdev->roce_cq_recv = NULL;
 526                 goto err;
 527         }
 528         smc_wr_add_dev(smcibdev);
 529         smcibdev->initialized = 1;
 530         return rc;
 531
 532 err:
 533         ib_destroy_cq(smcibdev->roce_cq_send);
 534         return rc;
 535 }
 536
 537 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 538 {
 539         if (!smcibdev->initialized)
 540                 return;
 541         smcibdev->initialized = 0;
 542         ib_destroy_cq(smcibdev->roce_cq_recv);
 543         ib_destroy_cq(smcibdev->roce_cq_send);
 544         smc_wr_remove_dev(smcibdev);
 545 }
 546
 547 static struct ib_client smc_ib_client;
 548
 549 /* callback function for ib_register_client() */
 550 static void smc_ib_add_dev(struct ib_device *ibdev)
 551 {
 552         struct smc_ib_device *smcibdev;
 553         u8 port_cnt;
 554         int i;
 555
 556         if (ibdev->node_type != RDMA_NODE_IB_CA)
 557                 return;
 558
 559         smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
 560         if (!smcibdev)
 561                 return;
 562
 563         smcibdev->ibdev = ibdev;
 564         INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 565         atomic_set(&smcibdev->lnk_cnt, 0);
 566         init_waitqueue_head(&smcibdev->lnks_deleted);
 567         spin_lock(&smc_ib_devices.lock);
 568         list_add_tail(&smcibdev->list, &smc_ib_devices.list);
 569         spin_unlock(&smc_ib_devices.lock);
 570         ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 571         INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 572                               smc_ib_global_event_handler);
 573         ib_register_event_handler(&smcibdev->event_handler);
 574
 575         /* trigger reading of the port attributes */
 576         port_cnt = smcibdev->ibdev->phys_port_cnt;
 577         for (i = 0;
 578              i < min_t(size_t, port_cnt, SMC_MAX_PORTS);
 579              i++) {
 580                 set_bit(i, &smcibdev->port_event_mask);
 581                 /* determine pnetids of the port */
 582                 smc_pnetid_by_dev_port(ibdev->dev.parent, i,
 583                                        smcibdev->pnetid[i]);
 584         }
 585         schedule_work(&smcibdev->port_event_work);
 586 }
 587
 588 /* callback function for ib_unregister_client() */
 589 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 590 {
 591         struct smc_ib_device *smcibdev;
 592
 593         smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
 594         if (!smcibdev || smcibdev->ibdev != ibdev)
 595                 return;
 596         ib_set_client_data(ibdev, &smc_ib_client, NULL);
 597         spin_lock(&smc_ib_devices.lock);
 598         list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
 599         spin_unlock(&smc_ib_devices.lock);
 600         smc_smcr_terminate_all(smcibdev);
 601         smc_ib_cleanup_per_ibdev(smcibdev);
 602         ib_unregister_event_handler(&smcibdev->event_handler);
 603         cancel_work_sync(&smcibdev->port_event_work);
 604         kfree(smcibdev);
 605 }
 606
 607 static struct ib_client smc_ib_client = {
 608         .name   = "smc_ib",
 609         .add    = smc_ib_add_dev,
 610         .remove = smc_ib_remove_dev,
 611 };
 612
 613 int __init smc_ib_register_client(void)
 614 {
 615         smc_ib_init_local_systemid();
 616         return ib_register_client(&smc_ib_client);
 617 }
 618
 619 void smc_ib_unregister_client(void)
 620 {
 621         ib_unregister_client(&smc_ib_client);
 622 }