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