net/smc/smc_ib.c

   1 /*
   2  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  *  IB infrastructure:
   5  *  Establish SMC-R as an Infiniband Client to be notified about added and
   6  *  removed IB devices of type RDMA.
   7  *  Determine device and port characteristics for these IB devices.
   8  *
   9  *  Copyright IBM Corp. 2016
  10  *
  11  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  12  */
  13
  14 #include <linux/random.h>
  15 #include <linux/workqueue.h>
  16 #include <rdma/ib_verbs.h>
  17
  18 #include "smc_pnet.h"
  19 #include "smc_ib.h"
  20 #include "smc_core.h"
  21 #include "smc_wr.h"
  22 #include "smc.h"
  23
  24 #define SMC_QP_MIN_RNR_TIMER            5
  25 #define SMC_QP_TIMEOUT                  15 /* 4096 * 2 ** timeout usec */
  26 #define SMC_QP_RETRY_CNT                        7 /* 7: infinite */
  27 #define SMC_QP_RNR_RETRY                        7 /* 7: infinite */
  28
  29 struct smc_ib_devices smc_ib_devices = {        /* smc-registered ib devices */
  30         .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
  31         .list = LIST_HEAD_INIT(smc_ib_devices.list),
  32 };
  33
  34 #define SMC_LOCAL_SYSTEMID_RESET        "%%%%%%%"
  35
  36 u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system
  37                                                                  * identifier
  38                                                                  */
  39
  40 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
  41                              struct ib_mr **mr)
  42 {
  43         int rc;
  44
  45         if (*mr)
  46                 return 0; /* already done */
  47
  48         /* obtain unique key -
  49          * next invocation of get_dma_mr returns a different key!
  50          */
  51         *mr = pd->device->get_dma_mr(pd, access_flags);
  52         rc = PTR_ERR_OR_ZERO(*mr);
  53         if (IS_ERR(*mr))
  54                 *mr = NULL;
  55         return rc;
  56 }
  57
  58 static int smc_ib_modify_qp_init(struct smc_link *lnk)
  59 {
  60         struct ib_qp_attr qp_attr;
  61
  62         memset(&qp_attr, 0, sizeof(qp_attr));
  63         qp_attr.qp_state = IB_QPS_INIT;
  64         qp_attr.pkey_index = 0;
  65         qp_attr.port_num = lnk->ibport;
  66         qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
  67                                 | IB_ACCESS_REMOTE_WRITE;
  68         return ib_modify_qp(lnk->roce_qp, &qp_attr,
  69                             IB_QP_STATE | IB_QP_PKEY_INDEX |
  70                             IB_QP_ACCESS_FLAGS | IB_QP_PORT);
  71 }
  72
  73 static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
  74 {
  75         enum ib_qp_attr_mask qp_attr_mask =
  76                 IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
  77                 IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
  78         struct ib_qp_attr qp_attr;
  79
  80         memset(&qp_attr, 0, sizeof(qp_attr));
  81         qp_attr.qp_state = IB_QPS_RTR;
  82         qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
  83         qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
  84         rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
  85         rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, 0, 1, 0);
  86         rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
  87         memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
  88                sizeof(lnk->peer_mac));
  89         qp_attr.dest_qp_num = lnk->peer_qpn;
  90         qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
  91         qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
  92                                          * requests
  93                                          */
  94         qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
  95
  96         return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
  97 }
  98
  99 int smc_ib_modify_qp_rts(struct smc_link *lnk)
 100 {
 101         struct ib_qp_attr qp_attr;
 102
 103         memset(&qp_attr, 0, sizeof(qp_attr));
 104         qp_attr.qp_state = IB_QPS_RTS;
 105         qp_attr.timeout = SMC_QP_TIMEOUT;       /* local ack timeout */
 106         qp_attr.retry_cnt = SMC_QP_RETRY_CNT;   /* retry count */
 107         qp_attr.rnr_retry = SMC_QP_RNR_RETRY;   /* RNR retries, 7=infinite */
 108         qp_attr.sq_psn = lnk->psn_initial;      /* starting send packet seq # */
 109         qp_attr.max_rd_atomic = 1;      /* # of outstanding RDMA reads and
 110                                          * atomic ops allowed
 111                                          */
 112         return ib_modify_qp(lnk->roce_qp, &qp_attr,
 113                             IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
 114                             IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
 115                             IB_QP_MAX_QP_RD_ATOMIC);
 116 }
 117
 118 int smc_ib_modify_qp_reset(struct smc_link *lnk)
 119 {
 120         struct ib_qp_attr qp_attr;
 121
 122         memset(&qp_attr, 0, sizeof(qp_attr));
 123         qp_attr.qp_state = IB_QPS_RESET;
 124         return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
 125 }
 126
 127 int smc_ib_ready_link(struct smc_link *lnk)
 128 {
 129         struct smc_link_group *lgr =
 130                 container_of(lnk, struct smc_link_group, lnk[0]);
 131         int rc = 0;
 132
 133         rc = smc_ib_modify_qp_init(lnk);
 134         if (rc)
 135                 goto out;
 136
 137         rc = smc_ib_modify_qp_rtr(lnk);
 138         if (rc)
 139                 goto out;
 140         smc_wr_remember_qp_attr(lnk);
 141         rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
 142                               IB_CQ_SOLICITED_MASK);
 143         if (rc)
 144                 goto out;
 145         rc = smc_wr_rx_post_init(lnk);
 146         if (rc)
 147                 goto out;
 148         smc_wr_remember_qp_attr(lnk);
 149
 150         if (lgr->role == SMC_SERV) {
 151                 rc = smc_ib_modify_qp_rts(lnk);
 152                 if (rc)
 153                         goto out;
 154                 smc_wr_remember_qp_attr(lnk);
 155         }
 156 out:
 157         return rc;
 158 }
 159
 160 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
 161 static void smc_ib_port_event_work(struct work_struct *work)
 162 {
 163         struct smc_ib_device *smcibdev = container_of(
 164                 work, struct smc_ib_device, port_event_work);
 165         u8 port_idx;
 166
 167         for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
 168                 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
 169                 clear_bit(port_idx, &smcibdev->port_event_mask);
 170         }
 171 }
 172
 173 /* can be called in IRQ context */
 174 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 175                                         struct ib_event *ibevent)
 176 {
 177         struct smc_ib_device *smcibdev;
 178         u8 port_idx;
 179
 180         smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 181
 182         switch (ibevent->event) {
 183         case IB_EVENT_PORT_ERR:
 184                 port_idx = ibevent->element.port_num - 1;
 185                 set_bit(port_idx, &smcibdev->port_event_mask);
 186                 schedule_work(&smcibdev->port_event_work);
 187                 /* fall through */
 188         case IB_EVENT_DEVICE_FATAL:
 189                 /* tbd in follow-on patch:
 190                  * abnormal close of corresponding connections
 191                  */
 192                 break;
 193         case IB_EVENT_PORT_ACTIVE:
 194                 port_idx = ibevent->element.port_num - 1;
 195                 set_bit(port_idx, &smcibdev->port_event_mask);
 196                 schedule_work(&smcibdev->port_event_work);
 197                 break;
 198         default:
 199                 break;
 200         }
 201 }
 202
 203 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
 204 {
 205         ib_dealloc_pd(lnk->roce_pd);
 206         lnk->roce_pd = NULL;
 207 }
 208
 209 int smc_ib_create_protection_domain(struct smc_link *lnk)
 210 {
 211         int rc;
 212
 213         lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
 214         rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
 215         if (IS_ERR(lnk->roce_pd))
 216                 lnk->roce_pd = NULL;
 217         return rc;
 218 }
 219
 220 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 221 {
 222         switch (ibevent->event) {
 223         case IB_EVENT_DEVICE_FATAL:
 224         case IB_EVENT_GID_CHANGE:
 225         case IB_EVENT_PORT_ERR:
 226         case IB_EVENT_QP_ACCESS_ERR:
 227                 /* tbd in follow-on patch:
 228                  * abnormal close of corresponding connections
 229                  */
 230                 break;
 231         default:
 232                 break;
 233         }
 234 }
 235
 236 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
 237 {
 238         ib_destroy_qp(lnk->roce_qp);
 239         lnk->roce_qp = NULL;
 240 }
 241
 242 /* create a queue pair within the protection domain for a link */
 243 int smc_ib_create_queue_pair(struct smc_link *lnk)
 244 {
 245         struct ib_qp_init_attr qp_attr = {
 246                 .event_handler = smc_ib_qp_event_handler,
 247                 .qp_context = lnk,
 248                 .send_cq = lnk->smcibdev->roce_cq_send,
 249                 .recv_cq = lnk->smcibdev->roce_cq_recv,
 250                 .srq = NULL,
 251                 .cap = {
 252                         .max_send_wr = SMC_WR_BUF_CNT,
 253                                 /* include unsolicited rdma_writes as well,
 254                                  * there are max. 2 RDMA_WRITE per 1 WR_SEND
 255                                  */
 256                         .max_recv_wr = SMC_WR_BUF_CNT * 3,
 257                         .max_send_sge = SMC_IB_MAX_SEND_SGE,
 258                         .max_recv_sge = 1,
 259                 },
 260                 .sq_sig_type = IB_SIGNAL_REQ_WR,
 261                 .qp_type = IB_QPT_RC,
 262         };
 263         int rc;
 264
 265         lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
 266         rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
 267         if (IS_ERR(lnk->roce_qp))
 268                 lnk->roce_qp = NULL;
 269         else
 270                 smc_wr_remember_qp_attr(lnk);
 271         return rc;
 272 }
 273
 274 /* map a new TX or RX buffer to DMA */
 275 int smc_ib_buf_map(struct smc_ib_device *smcibdev, int buf_size,
 276                    struct smc_buf_desc *buf_slot,
 277                    enum dma_data_direction data_direction)
 278 {
 279         int rc = 0;
 280
 281         if (buf_slot->dma_addr[SMC_SINGLE_LINK])
 282                 return rc; /* already mapped */
 283         buf_slot->dma_addr[SMC_SINGLE_LINK] =
 284                 ib_dma_map_single(smcibdev->ibdev, buf_slot->cpu_addr,
 285                                   buf_size, data_direction);
 286         if (ib_dma_mapping_error(smcibdev->ibdev,
 287                                  buf_slot->dma_addr[SMC_SINGLE_LINK]))
 288                 rc = -EIO;
 289         return rc;
 290 }
 291
 292 void smc_ib_buf_unmap(struct smc_ib_device *smcibdev, int buf_size,
 293                       struct smc_buf_desc *buf_slot,
 294                       enum dma_data_direction data_direction)
 295 {
 296         if (!buf_slot->dma_addr[SMC_SINGLE_LINK])
 297                 return; /* already unmapped */
 298         ib_dma_unmap_single(smcibdev->ibdev, *buf_slot->dma_addr, buf_size,
 299                             data_direction);
 300         buf_slot->dma_addr[SMC_SINGLE_LINK] = 0;
 301 }
 302
 303 static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport)
 304 {
 305         struct net_device *ndev;
 306         int rc;
 307
 308         rc = ib_query_gid(smcibdev->ibdev, ibport, 0,
 309                           &smcibdev->gid[ibport - 1], NULL);
 310         /* the SMC protocol requires specification of the roce MAC address;
 311          * if net_device cannot be determined, it can be derived from gid 0
 312          */
 313         ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport);
 314         if (ndev) {
 315                 memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN);
 316         } else if (!rc) {
 317                 memcpy(&smcibdev->mac[ibport - 1][0],
 318                        &smcibdev->gid[ibport - 1].raw[8], 3);
 319                 memcpy(&smcibdev->mac[ibport - 1][3],
 320                        &smcibdev->gid[ibport - 1].raw[13], 3);
 321                 smcibdev->mac[ibport - 1][0] &= ~0x02;
 322         }
 323         return rc;
 324 }
 325
 326 /* Create an identifier unique for this instance of SMC-R.
 327  * The MAC-address of the first active registered IB device
 328  * plus a random 2-byte number is used to create this identifier.
 329  * This name is delivered to the peer during connection initialization.
 330  */
 331 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
 332                                                 u8 ibport)
 333 {
 334         memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
 335                sizeof(smcibdev->mac[ibport - 1]));
 336         get_random_bytes(&local_systemid[0], 2);
 337 }
 338
 339 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
 340 {
 341         return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
 342 }
 343
 344 int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 345 {
 346         int rc;
 347
 348         memset(&smcibdev->pattr[ibport - 1], 0,
 349                sizeof(smcibdev->pattr[ibport - 1]));
 350         rc = ib_query_port(smcibdev->ibdev, ibport,
 351                            &smcibdev->pattr[ibport - 1]);
 352         if (rc)
 353                 goto out;
 354         rc = smc_ib_fill_gid_and_mac(smcibdev, ibport);
 355         if (rc)
 356                 goto out;
 357         if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
 358                      sizeof(local_systemid)) &&
 359             smc_ib_port_active(smcibdev, ibport))
 360                 /* create unique system identifier */
 361                 smc_ib_define_local_systemid(smcibdev, ibport);
 362 out:
 363         return rc;
 364 }
 365
 366 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
 367 {
 368         struct ib_cq_init_attr cqattr = {
 369                 .cqe = SMC_WR_MAX_CQE, .comp_vector = 0 };
 370         long rc;
 371
 372         smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
 373                                               smc_wr_tx_cq_handler, NULL,
 374                                               smcibdev, &cqattr);
 375         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
 376         if (IS_ERR(smcibdev->roce_cq_send)) {
 377                 smcibdev->roce_cq_send = NULL;
 378                 return rc;
 379         }
 380         smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
 381                                               smc_wr_rx_cq_handler, NULL,
 382                                               smcibdev, &cqattr);
 383         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
 384         if (IS_ERR(smcibdev->roce_cq_recv)) {
 385                 smcibdev->roce_cq_recv = NULL;
 386                 goto err;
 387         }
 388         INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 389                               smc_ib_global_event_handler);
 390         ib_register_event_handler(&smcibdev->event_handler);
 391         smc_wr_add_dev(smcibdev);
 392         smcibdev->initialized = 1;
 393         return rc;
 394
 395 err:
 396         ib_destroy_cq(smcibdev->roce_cq_send);
 397         return rc;
 398 }
 399
 400 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 401 {
 402         if (!smcibdev->initialized)
 403                 return;
 404         smc_wr_remove_dev(smcibdev);
 405         ib_unregister_event_handler(&smcibdev->event_handler);
 406         ib_destroy_cq(smcibdev->roce_cq_recv);
 407         ib_destroy_cq(smcibdev->roce_cq_send);
 408 }
 409
 410 static struct ib_client smc_ib_client;
 411
 412 /* callback function for ib_register_client() */
 413 static void smc_ib_add_dev(struct ib_device *ibdev)
 414 {
 415         struct smc_ib_device *smcibdev;
 416
 417         if (ibdev->node_type != RDMA_NODE_IB_CA)
 418                 return;
 419
 420         smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
 421         if (!smcibdev)
 422                 return;
 423
 424         smcibdev->ibdev = ibdev;
 425         INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 426
 427         spin_lock(&smc_ib_devices.lock);
 428         list_add_tail(&smcibdev->list, &smc_ib_devices.list);
 429         spin_unlock(&smc_ib_devices.lock);
 430         ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 431 }
 432
 433 /* callback function for ib_register_client() */
 434 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 435 {
 436         struct smc_ib_device *smcibdev;
 437
 438         smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
 439         ib_set_client_data(ibdev, &smc_ib_client, NULL);
 440         spin_lock(&smc_ib_devices.lock);
 441         list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
 442         spin_unlock(&smc_ib_devices.lock);
 443         smc_pnet_remove_by_ibdev(smcibdev);
 444         smc_ib_cleanup_per_ibdev(smcibdev);
 445         kfree(smcibdev);
 446 }
 447
 448 static struct ib_client smc_ib_client = {
 449         .name   = "smc_ib",
 450         .add    = smc_ib_add_dev,
 451         .remove = smc_ib_remove_dev,
 452 };
 453
 454 int __init smc_ib_register_client(void)
 455 {
 456         return ib_register_client(&smc_ib_client);
 457 }
 458
 459 void smc_ib_unregister_client(void)
 460 {
 461         ib_unregister_client(&smc_ib_client);
 462 }