drivers/infiniband/sw/siw/siw_main.c

   1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
   2
   3 /* Authors: Bernard Metzler <bmt@zurich.ibm.com> */
   4 /* Copyright (c) 2008-2019, IBM Corporation */
   5
   6 #include <linux/init.h>
   7 #include <linux/errno.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/inetdevice.h>
  10 #include <net/net_namespace.h>
  11 #include <linux/rtnetlink.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/list.h>
  14 #include <linux/kernel.h>
  15 #include <linux/sched.h>
  16 #include <linux/module.h>
  17 #include <linux/dma-mapping.h>
  18
  19 #include <net/addrconf.h>
  20 #include <rdma/ib_verbs.h>
  21 #include <rdma/ib_user_verbs.h>
  22 #include <rdma/rdma_netlink.h>
  23 #include <linux/kthread.h>
  24
  25 #include "siw.h"
  26 #include "siw_verbs.h"
  27
  28 MODULE_AUTHOR("Bernard Metzler");
  29 MODULE_DESCRIPTION("Software iWARP Driver");
  30 MODULE_LICENSE("Dual BSD/GPL");
  31
  32 /* transmit from user buffer, if possible */
  33 const bool zcopy_tx = true;
  34
  35 /* Restrict usage of GSO, if hardware peer iwarp is unable to process
  36  * large packets. try_gso = true lets siw try to use local GSO,
  37  * if peer agrees.  Not using GSO severly limits siw maximum tx bandwidth.
  38  */
  39 const bool try_gso;
  40
  41 /* Attach siw also with loopback devices */
  42 const bool loopback_enabled = true;
  43
  44 /* We try to negotiate CRC on, if true */
  45 const bool mpa_crc_required;
  46
  47 /* MPA CRC on/off enforced */
  48 const bool mpa_crc_strict;
  49
  50 /* Control TCP_NODELAY socket option */
  51 const bool siw_tcp_nagle;
  52
  53 /* Select MPA version to be used during connection setup */
  54 u_char mpa_version = MPA_REVISION_2;
  55
  56 /* Selects MPA P2P mode (additional handshake during connection
  57  * setup, if true.
  58  */
  59 const bool peer_to_peer;
  60
  61 struct task_struct *siw_tx_thread[NR_CPUS];
  62 struct crypto_shash *siw_crypto_shash;
  63
  64 static int siw_device_register(struct siw_device *sdev, const char *name)
  65 {
  66         struct ib_device *base_dev = &sdev->base_dev;
  67         static int dev_id = 1;
  68         int rv;
  69
  70         rv = ib_register_device(base_dev, name);
  71         if (rv) {
  72                 pr_warn("siw: device registration error %d\n", rv);
  73                 return rv;
  74         }
  75         sdev->vendor_part_id = dev_id++;
  76
  77         siw_dbg(base_dev, "HWaddr=%pM\n", sdev->netdev->dev_addr);
  78
  79         return 0;
  80 }
  81
  82 static void siw_device_cleanup(struct ib_device *base_dev)
  83 {
  84         struct siw_device *sdev = to_siw_dev(base_dev);
  85
  86         xa_destroy(&sdev->qp_xa);
  87         xa_destroy(&sdev->mem_xa);
  88 }
  89
  90 static int siw_create_tx_threads(void)
  91 {
  92         int cpu, assigned = 0;
  93
  94         for_each_online_cpu(cpu) {
  95                 /* Skip HT cores */
  96                 if (cpu % cpumask_weight(topology_sibling_cpumask(cpu)))
  97                         continue;
  98
  99                 siw_tx_thread[cpu] =
 100                         kthread_create(siw_run_sq, (unsigned long *)(long)cpu,
 101                                        "siw_tx/%d", cpu);
 102                 if (IS_ERR(siw_tx_thread[cpu])) {
 103                         siw_tx_thread[cpu] = NULL;
 104                         continue;
 105                 }
 106                 kthread_bind(siw_tx_thread[cpu], cpu);
 107
 108                 wake_up_process(siw_tx_thread[cpu]);
 109                 assigned++;
 110         }
 111         return assigned;
 112 }
 113
 114 static int siw_dev_qualified(struct net_device *netdev)
 115 {
 116         /*
 117          * Additional hardware support can be added here
 118          * (e.g. ARPHRD_FDDI, ARPHRD_ATM, ...) - see
 119          * <linux/if_arp.h> for type identifiers.
 120          */
 121         if (netdev->type == ARPHRD_ETHER || netdev->type == ARPHRD_IEEE802 ||
 122             (netdev->type == ARPHRD_LOOPBACK && loopback_enabled))
 123                 return 1;
 124
 125         return 0;
 126 }
 127
 128 static DEFINE_PER_CPU(atomic_t, siw_use_cnt);
 129
 130 static struct {
 131         struct cpumask **tx_valid_cpus;
 132         int num_nodes;
 133 } siw_cpu_info;
 134
 135 static int siw_init_cpulist(void)
 136 {
 137         int i, num_nodes = num_possible_nodes();
 138
 139         memset(siw_tx_thread, 0, sizeof(siw_tx_thread));
 140
 141         siw_cpu_info.num_nodes = num_nodes;
 142
 143         siw_cpu_info.tx_valid_cpus =
 144                 kcalloc(num_nodes, sizeof(struct cpumask *), GFP_KERNEL);
 145         if (!siw_cpu_info.tx_valid_cpus) {
 146                 siw_cpu_info.num_nodes = 0;
 147                 return -ENOMEM;
 148         }
 149         for (i = 0; i < siw_cpu_info.num_nodes; i++) {
 150                 siw_cpu_info.tx_valid_cpus[i] =
 151                         kzalloc(sizeof(struct cpumask), GFP_KERNEL);
 152                 if (!siw_cpu_info.tx_valid_cpus[i])
 153                         goto out_err;
 154
 155                 cpumask_clear(siw_cpu_info.tx_valid_cpus[i]);
 156         }
 157         for_each_possible_cpu(i)
 158                 cpumask_set_cpu(i, siw_cpu_info.tx_valid_cpus[cpu_to_node(i)]);
 159
 160         return 0;
 161
 162 out_err:
 163         siw_cpu_info.num_nodes = 0;
 164         while (--i >= 0)
 165                 kfree(siw_cpu_info.tx_valid_cpus[i]);
 166         kfree(siw_cpu_info.tx_valid_cpus);
 167         siw_cpu_info.tx_valid_cpus = NULL;
 168
 169         return -ENOMEM;
 170 }
 171
 172 static void siw_destroy_cpulist(void)
 173 {
 174         int i = 0;
 175
 176         while (i < siw_cpu_info.num_nodes)
 177                 kfree(siw_cpu_info.tx_valid_cpus[i++]);
 178
 179         kfree(siw_cpu_info.tx_valid_cpus);
 180 }
 181
 182 /*
 183  * Choose CPU with least number of active QP's from NUMA node of
 184  * TX interface.
 185  */
 186 int siw_get_tx_cpu(struct siw_device *sdev)
 187 {
 188         const struct cpumask *tx_cpumask;
 189         int i, num_cpus, cpu, min_use, node = sdev->numa_node, tx_cpu = -1;
 190
 191         if (node < 0)
 192                 tx_cpumask = cpu_online_mask;
 193         else
 194                 tx_cpumask = siw_cpu_info.tx_valid_cpus[node];
 195
 196         num_cpus = cpumask_weight(tx_cpumask);
 197         if (!num_cpus) {
 198                 /* no CPU on this NUMA node */
 199                 tx_cpumask = cpu_online_mask;
 200                 num_cpus = cpumask_weight(tx_cpumask);
 201         }
 202         if (!num_cpus)
 203                 goto out;
 204
 205         cpu = cpumask_first(tx_cpumask);
 206
 207         for (i = 0, min_use = SIW_MAX_QP; i < num_cpus;
 208              i++, cpu = cpumask_next(cpu, tx_cpumask)) {
 209                 int usage;
 210
 211                 /* Skip any cores which have no TX thread */
 212                 if (!siw_tx_thread[cpu])
 213                         continue;
 214
 215                 usage = atomic_read(&per_cpu(siw_use_cnt, cpu));
 216                 if (usage <= min_use) {
 217                         tx_cpu = cpu;
 218                         min_use = usage;
 219                 }
 220         }
 221         siw_dbg(&sdev->base_dev,
 222                 "tx cpu %d, node %d, %d qp's\n", tx_cpu, node, min_use);
 223
 224 out:
 225         if (tx_cpu >= 0)
 226                 atomic_inc(&per_cpu(siw_use_cnt, tx_cpu));
 227         else
 228                 pr_warn("siw: no tx cpu found\n");
 229
 230         return tx_cpu;
 231 }
 232
 233 void siw_put_tx_cpu(int cpu)
 234 {
 235         atomic_dec(&per_cpu(siw_use_cnt, cpu));
 236 }
 237
 238 static struct ib_qp *siw_get_base_qp(struct ib_device *base_dev, int id)
 239 {
 240         struct siw_qp *qp = siw_qp_id2obj(to_siw_dev(base_dev), id);
 241
 242         if (qp) {
 243                 /*
 244                  * siw_qp_id2obj() increments object reference count
 245                  */
 246                 siw_qp_put(qp);
 247                 return &qp->base_qp;
 248         }
 249         return NULL;
 250 }
 251
 252 static const struct ib_device_ops siw_device_ops = {
 253         .owner = THIS_MODULE,
 254         .uverbs_abi_ver = SIW_ABI_VERSION,
 255         .driver_id = RDMA_DRIVER_SIW,
 256
 257         .alloc_mr = siw_alloc_mr,
 258         .alloc_pd = siw_alloc_pd,
 259         .alloc_ucontext = siw_alloc_ucontext,
 260         .create_cq = siw_create_cq,
 261         .create_qp = siw_create_qp,
 262         .create_srq = siw_create_srq,
 263         .dealloc_driver = siw_device_cleanup,
 264         .dealloc_pd = siw_dealloc_pd,
 265         .dealloc_ucontext = siw_dealloc_ucontext,
 266         .dereg_mr = siw_dereg_mr,
 267         .destroy_cq = siw_destroy_cq,
 268         .destroy_qp = siw_destroy_qp,
 269         .destroy_srq = siw_destroy_srq,
 270         .get_dma_mr = siw_get_dma_mr,
 271         .get_port_immutable = siw_get_port_immutable,
 272         .iw_accept = siw_accept,
 273         .iw_add_ref = siw_qp_get_ref,
 274         .iw_connect = siw_connect,
 275         .iw_create_listen = siw_create_listen,
 276         .iw_destroy_listen = siw_destroy_listen,
 277         .iw_get_qp = siw_get_base_qp,
 278         .iw_reject = siw_reject,
 279         .iw_rem_ref = siw_qp_put_ref,
 280         .map_mr_sg = siw_map_mr_sg,
 281         .mmap = siw_mmap,
 282         .mmap_free = siw_mmap_free,
 283         .modify_qp = siw_verbs_modify_qp,
 284         .modify_srq = siw_modify_srq,
 285         .poll_cq = siw_poll_cq,
 286         .post_recv = siw_post_receive,
 287         .post_send = siw_post_send,
 288         .post_srq_recv = siw_post_srq_recv,
 289         .query_device = siw_query_device,
 290         .query_gid = siw_query_gid,
 291         .query_pkey = siw_query_pkey,
 292         .query_port = siw_query_port,
 293         .query_qp = siw_query_qp,
 294         .query_srq = siw_query_srq,
 295         .req_notify_cq = siw_req_notify_cq,
 296         .reg_user_mr = siw_reg_user_mr,
 297
 298         INIT_RDMA_OBJ_SIZE(ib_cq, siw_cq, base_cq),
 299         INIT_RDMA_OBJ_SIZE(ib_pd, siw_pd, base_pd),
 300         INIT_RDMA_OBJ_SIZE(ib_srq, siw_srq, base_srq),
 301         INIT_RDMA_OBJ_SIZE(ib_ucontext, siw_ucontext, base_ucontext),
 302 };
 303
 304 static struct siw_device *siw_device_create(struct net_device *netdev)
 305 {
 306         struct siw_device *sdev = NULL;
 307         struct ib_device *base_dev;
 308         struct device *parent = netdev->dev.parent;
 309         int rv;
 310
 311         if (!parent) {
 312                 /*
 313                  * The loopback device has no parent device,
 314                  * so it appears as a top-level device. To support
 315                  * loopback device connectivity, take this device
 316                  * as the parent device. Skip all other devices
 317                  * w/o parent device.
 318                  */
 319                 if (netdev->type != ARPHRD_LOOPBACK) {
 320                         pr_warn("siw: device %s error: no parent device\n",
 321                                 netdev->name);
 322                         return NULL;
 323                 }
 324                 parent = &netdev->dev;
 325         }
 326         sdev = ib_alloc_device(siw_device, base_dev);
 327         if (!sdev)
 328                 return NULL;
 329
 330         base_dev = &sdev->base_dev;
 331
 332         sdev->netdev = netdev;
 333
 334         if (netdev->type != ARPHRD_LOOPBACK) {
 335                 addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,
 336                                     netdev->dev_addr);
 337         } else {
 338                 /*
 339                  * The loopback device does not have a HW address,
 340                  * but connection mangagement lib expects gid != 0
 341                  */
 342                 size_t len = min_t(size_t, strlen(base_dev->name), 6);
 343                 char addr[6] = { };
 344
 345                 memcpy(addr, base_dev->name, len);
 346                 addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,
 347                                     addr);
 348         }
 349         base_dev->uverbs_cmd_mask =
 350                 (1ull << IB_USER_VERBS_CMD_QUERY_DEVICE) |
 351                 (1ull << IB_USER_VERBS_CMD_QUERY_PORT) |
 352                 (1ull << IB_USER_VERBS_CMD_GET_CONTEXT) |
 353                 (1ull << IB_USER_VERBS_CMD_ALLOC_PD) |
 354                 (1ull << IB_USER_VERBS_CMD_DEALLOC_PD) |
 355                 (1ull << IB_USER_VERBS_CMD_REG_MR) |
 356                 (1ull << IB_USER_VERBS_CMD_DEREG_MR) |
 357                 (1ull << IB_USER_VERBS_CMD_CREATE_COMP_CHANNEL) |
 358                 (1ull << IB_USER_VERBS_CMD_CREATE_CQ) |
 359                 (1ull << IB_USER_VERBS_CMD_POLL_CQ) |
 360                 (1ull << IB_USER_VERBS_CMD_REQ_NOTIFY_CQ) |
 361                 (1ull << IB_USER_VERBS_CMD_DESTROY_CQ) |
 362                 (1ull << IB_USER_VERBS_CMD_CREATE_QP) |
 363                 (1ull << IB_USER_VERBS_CMD_QUERY_QP) |
 364                 (1ull << IB_USER_VERBS_CMD_MODIFY_QP) |
 365                 (1ull << IB_USER_VERBS_CMD_DESTROY_QP) |
 366                 (1ull << IB_USER_VERBS_CMD_POST_SEND) |
 367                 (1ull << IB_USER_VERBS_CMD_POST_RECV) |
 368                 (1ull << IB_USER_VERBS_CMD_CREATE_SRQ) |
 369                 (1ull << IB_USER_VERBS_CMD_POST_SRQ_RECV) |
 370                 (1ull << IB_USER_VERBS_CMD_MODIFY_SRQ) |
 371                 (1ull << IB_USER_VERBS_CMD_QUERY_SRQ) |
 372                 (1ull << IB_USER_VERBS_CMD_DESTROY_SRQ);
 373
 374         base_dev->node_type = RDMA_NODE_RNIC;
 375         memcpy(base_dev->node_desc, SIW_NODE_DESC_COMMON,
 376                sizeof(SIW_NODE_DESC_COMMON));
 377
 378         /*
 379          * Current model (one-to-one device association):
 380          * One Softiwarp device per net_device or, equivalently,
 381          * per physical port.
 382          */
 383         base_dev->phys_port_cnt = 1;
 384         base_dev->dev.parent = parent;
 385         base_dev->dev.dma_ops = &dma_virt_ops;
 386         base_dev->dev.dma_parms = &sdev->dma_parms;
 387         sdev->dma_parms = (struct device_dma_parameters)
 388                 { .max_segment_size = SZ_2G };
 389         base_dev->num_comp_vectors = num_possible_cpus();
 390
 391         ib_set_device_ops(base_dev, &siw_device_ops);
 392         rv = ib_device_set_netdev(base_dev, netdev, 1);
 393         if (rv)
 394                 goto error;
 395
 396         memcpy(base_dev->iw_ifname, netdev->name,
 397                sizeof(base_dev->iw_ifname));
 398
 399         /* Disable TCP port mapping */
 400         base_dev->iw_driver_flags = IW_F_NO_PORT_MAP,
 401
 402         sdev->attrs.max_qp = SIW_MAX_QP;
 403         sdev->attrs.max_qp_wr = SIW_MAX_QP_WR;
 404         sdev->attrs.max_ord = SIW_MAX_ORD_QP;
 405         sdev->attrs.max_ird = SIW_MAX_IRD_QP;
 406         sdev->attrs.max_sge = SIW_MAX_SGE;
 407         sdev->attrs.max_sge_rd = SIW_MAX_SGE_RD;
 408         sdev->attrs.max_cq = SIW_MAX_CQ;
 409         sdev->attrs.max_cqe = SIW_MAX_CQE;
 410         sdev->attrs.max_mr = SIW_MAX_MR;
 411         sdev->attrs.max_pd = SIW_MAX_PD;
 412         sdev->attrs.max_mw = SIW_MAX_MW;
 413         sdev->attrs.max_fmr = SIW_MAX_FMR;
 414         sdev->attrs.max_srq = SIW_MAX_SRQ;
 415         sdev->attrs.max_srq_wr = SIW_MAX_SRQ_WR;
 416         sdev->attrs.max_srq_sge = SIW_MAX_SGE;
 417
 418         xa_init_flags(&sdev->qp_xa, XA_FLAGS_ALLOC1);
 419         xa_init_flags(&sdev->mem_xa, XA_FLAGS_ALLOC1);
 420
 421         INIT_LIST_HEAD(&sdev->cep_list);
 422         INIT_LIST_HEAD(&sdev->qp_list);
 423
 424         atomic_set(&sdev->num_ctx, 0);
 425         atomic_set(&sdev->num_srq, 0);
 426         atomic_set(&sdev->num_qp, 0);
 427         atomic_set(&sdev->num_cq, 0);
 428         atomic_set(&sdev->num_mr, 0);
 429         atomic_set(&sdev->num_pd, 0);
 430
 431         sdev->numa_node = dev_to_node(parent);
 432         spin_lock_init(&sdev->lock);
 433
 434         return sdev;
 435 error:
 436         ib_dealloc_device(base_dev);
 437
 438         return NULL;
 439 }
 440
 441 /*
 442  * Network link becomes unavailable. Mark all
 443  * affected QP's accordingly.
 444  */
 445 static void siw_netdev_down(struct work_struct *work)
 446 {
 447         struct siw_device *sdev =
 448                 container_of(work, struct siw_device, netdev_down);
 449
 450         struct siw_qp_attrs qp_attrs;
 451         struct list_head *pos, *tmp;
 452
 453         memset(&qp_attrs, 0, sizeof(qp_attrs));
 454         qp_attrs.state = SIW_QP_STATE_ERROR;
 455
 456         list_for_each_safe(pos, tmp, &sdev->qp_list) {
 457                 struct siw_qp *qp = list_entry(pos, struct siw_qp, devq);
 458
 459                 down_write(&qp->state_lock);
 460                 WARN_ON(siw_qp_modify(qp, &qp_attrs, SIW_QP_ATTR_STATE));
 461                 up_write(&qp->state_lock);
 462         }
 463         ib_device_put(&sdev->base_dev);
 464 }
 465
 466 static void siw_device_goes_down(struct siw_device *sdev)
 467 {
 468         if (ib_device_try_get(&sdev->base_dev)) {
 469                 INIT_WORK(&sdev->netdev_down, siw_netdev_down);
 470                 schedule_work(&sdev->netdev_down);
 471         }
 472 }
 473
 474 static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
 475                             void *arg)
 476 {
 477         struct net_device *netdev = netdev_notifier_info_to_dev(arg);
 478         struct ib_device *base_dev;
 479         struct siw_device *sdev;
 480
 481         dev_dbg(&netdev->dev, "siw: event %lu\n", event);
 482
 483         if (dev_net(netdev) != &init_net)
 484                 return NOTIFY_OK;
 485
 486         base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
 487         if (!base_dev)
 488                 return NOTIFY_OK;
 489
 490         sdev = to_siw_dev(base_dev);
 491
 492         switch (event) {
 493         case NETDEV_UP:
 494                 sdev->state = IB_PORT_ACTIVE;
 495                 siw_port_event(sdev, 1, IB_EVENT_PORT_ACTIVE);
 496                 break;
 497
 498         case NETDEV_GOING_DOWN:
 499                 siw_device_goes_down(sdev);
 500                 break;
 501
 502         case NETDEV_DOWN:
 503                 sdev->state = IB_PORT_DOWN;
 504                 siw_port_event(sdev, 1, IB_EVENT_PORT_ERR);
 505                 break;
 506
 507         case NETDEV_REGISTER:
 508                 /*
 509                  * Device registration now handled only by
 510                  * rdma netlink commands. So it shall be impossible
 511                  * to end up here with a valid siw device.
 512                  */
 513                 siw_dbg(base_dev, "unexpected NETDEV_REGISTER event\n");
 514                 break;
 515
 516         case NETDEV_UNREGISTER:
 517                 ib_unregister_device_queued(&sdev->base_dev);
 518                 break;
 519
 520         case NETDEV_CHANGEADDR:
 521                 siw_port_event(sdev, 1, IB_EVENT_LID_CHANGE);
 522                 break;
 523         /*
 524          * Todo: Below netdev events are currently not handled.
 525          */
 526         case NETDEV_CHANGEMTU:
 527         case NETDEV_CHANGE:
 528                 break;
 529
 530         default:
 531                 break;
 532         }
 533         ib_device_put(&sdev->base_dev);
 534
 535         return NOTIFY_OK;
 536 }
 537
 538 static struct notifier_block siw_netdev_nb = {
 539         .notifier_call = siw_netdev_event,
 540 };
 541
 542 static int siw_newlink(const char *basedev_name, struct net_device *netdev)
 543 {
 544         struct ib_device *base_dev;
 545         struct siw_device *sdev = NULL;
 546         int rv = -ENOMEM;
 547
 548         if (!siw_dev_qualified(netdev))
 549                 return -EINVAL;
 550
 551         base_dev = ib_device_get_by_netdev(netdev, RDMA_DRIVER_SIW);
 552         if (base_dev) {
 553                 ib_device_put(base_dev);
 554                 return -EEXIST;
 555         }
 556         sdev = siw_device_create(netdev);
 557         if (sdev) {
 558                 dev_dbg(&netdev->dev, "siw: new device\n");
 559
 560                 if (netif_running(netdev) && netif_carrier_ok(netdev))
 561                         sdev->state = IB_PORT_ACTIVE;
 562                 else
 563                         sdev->state = IB_PORT_DOWN;
 564
 565                 rv = siw_device_register(sdev, basedev_name);
 566                 if (rv)
 567                         ib_dealloc_device(&sdev->base_dev);
 568         }
 569         return rv;
 570 }
 571
 572 static struct rdma_link_ops siw_link_ops = {
 573         .type = "siw",
 574         .newlink = siw_newlink,
 575 };
 576
 577 /*
 578  * siw_init_module - Initialize Softiwarp module and register with netdev
 579  *                   subsystem.
 580  */
 581 static __init int siw_init_module(void)
 582 {
 583         int rv;
 584         int nr_cpu;
 585
 586         if (SENDPAGE_THRESH < SIW_MAX_INLINE) {
 587                 pr_info("siw: sendpage threshold too small: %u\n",
 588                         (int)SENDPAGE_THRESH);
 589                 rv = -EINVAL;
 590                 goto out_error;
 591         }
 592         rv = siw_init_cpulist();
 593         if (rv)
 594                 goto out_error;
 595
 596         rv = siw_cm_init();
 597         if (rv)
 598                 goto out_error;
 599
 600         if (!siw_create_tx_threads()) {
 601                 pr_info("siw: Could not start any TX thread\n");
 602                 rv = -ENOMEM;
 603                 goto out_error;
 604         }
 605         /*
 606          * Locate CRC32 algorithm. If unsuccessful, fail
 607          * loading siw only, if CRC is required.
 608          */
 609         siw_crypto_shash = crypto_alloc_shash("crc32c", 0, 0);
 610         if (IS_ERR(siw_crypto_shash)) {
 611                 pr_info("siw: Loading CRC32c failed: %ld\n",
 612                         PTR_ERR(siw_crypto_shash));
 613                 siw_crypto_shash = NULL;
 614                 if (mpa_crc_required) {
 615                         rv = -EOPNOTSUPP;
 616                         goto out_error;
 617                 }
 618         }
 619         rv = register_netdevice_notifier(&siw_netdev_nb);
 620         if (rv)
 621                 goto out_error;
 622
 623         rdma_link_register(&siw_link_ops);
 624
 625         pr_info("SoftiWARP attached\n");
 626         return 0;
 627
 628 out_error:
 629         for (nr_cpu = 0; nr_cpu < nr_cpu_ids; nr_cpu++) {
 630                 if (siw_tx_thread[nr_cpu]) {
 631                         siw_stop_tx_thread(nr_cpu);
 632                         siw_tx_thread[nr_cpu] = NULL;
 633                 }
 634         }
 635         if (siw_crypto_shash)
 636                 crypto_free_shash(siw_crypto_shash);
 637
 638         pr_info("SoftIWARP attach failed. Error: %d\n", rv);
 639
 640         siw_cm_exit();
 641         siw_destroy_cpulist();
 642
 643         return rv;
 644 }
 645
 646 static void __exit siw_exit_module(void)
 647 {
 648         int cpu;
 649
 650         for_each_possible_cpu(cpu) {
 651                 if (siw_tx_thread[cpu]) {
 652                         siw_stop_tx_thread(cpu);
 653                         siw_tx_thread[cpu] = NULL;
 654                 }
 655         }
 656         unregister_netdevice_notifier(&siw_netdev_nb);
 657         rdma_link_unregister(&siw_link_ops);
 658         ib_unregister_driver(RDMA_DRIVER_SIW);
 659
 660         siw_cm_exit();
 661
 662         siw_destroy_cpulist();
 663
 664         if (siw_crypto_shash)
 665                 crypto_free_shash(siw_crypto_shash);
 666
 667         pr_info("SoftiWARP detached\n");
 668 }
 669
 670 module_init(siw_init_module);
 671 module_exit(siw_exit_module);
 672
 673 MODULE_ALIAS_RDMA_LINK("siw");