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
  20 #include "smc_pnet.h"
  21 #include "smc_ib.h"
  22 #include "smc_core.h"
  23 #include "smc_wr.h"
  24 #include "smc.h"
  25
  26 #define SMC_QP_MIN_RNR_TIMER            5
  27 #define SMC_QP_TIMEOUT                  15 /* 4096 * 2 ** timeout usec */
  28 #define SMC_QP_RETRY_CNT                        7 /* 7: infinite */
  29 #define SMC_QP_RNR_RETRY                        7 /* 7: infinite */
  30
  31 struct smc_ib_devices smc_ib_devices = {        /* smc-registered ib devices */
  32         .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
  33         .list = LIST_HEAD_INIT(smc_ib_devices.list),
  34 };
  35
  36 #define SMC_LOCAL_SYSTEMID_RESET        "%%%%%%%"
  37
  38 u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system
  39                                                                  * identifier
  40                                                                  */
  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, 0, 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 =
 114                 container_of(lnk, struct smc_link_group, lnk[0]);
 115         int rc = 0;
 116
 117         rc = smc_ib_modify_qp_init(lnk);
 118         if (rc)
 119                 goto out;
 120
 121         rc = smc_ib_modify_qp_rtr(lnk);
 122         if (rc)
 123                 goto out;
 124         smc_wr_remember_qp_attr(lnk);
 125         rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
 126                               IB_CQ_SOLICITED_MASK);
 127         if (rc)
 128                 goto out;
 129         rc = smc_wr_rx_post_init(lnk);
 130         if (rc)
 131                 goto out;
 132         smc_wr_remember_qp_attr(lnk);
 133
 134         if (lgr->role == SMC_SERV) {
 135                 rc = smc_ib_modify_qp_rts(lnk);
 136                 if (rc)
 137                         goto out;
 138                 smc_wr_remember_qp_attr(lnk);
 139         }
 140 out:
 141         return rc;
 142 }
 143
 144 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
 145 static void smc_ib_port_event_work(struct work_struct *work)
 146 {
 147         struct smc_ib_device *smcibdev = container_of(
 148                 work, struct smc_ib_device, port_event_work);
 149         u8 port_idx;
 150
 151         for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
 152                 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
 153                 clear_bit(port_idx, &smcibdev->port_event_mask);
 154         }
 155 }
 156
 157 /* can be called in IRQ context */
 158 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 159                                         struct ib_event *ibevent)
 160 {
 161         struct smc_ib_device *smcibdev;
 162         u8 port_idx;
 163
 164         smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 165
 166         switch (ibevent->event) {
 167         case IB_EVENT_PORT_ERR:
 168                 port_idx = ibevent->element.port_num - 1;
 169                 set_bit(port_idx, &smcibdev->port_event_mask);
 170                 schedule_work(&smcibdev->port_event_work);
 171                 /* fall through */
 172         case IB_EVENT_DEVICE_FATAL:
 173                 /* tbd in follow-on patch:
 174                  * abnormal close of corresponding connections
 175                  */
 176                 break;
 177         case IB_EVENT_PORT_ACTIVE:
 178                 port_idx = ibevent->element.port_num - 1;
 179                 set_bit(port_idx, &smcibdev->port_event_mask);
 180                 schedule_work(&smcibdev->port_event_work);
 181                 break;
 182         default:
 183                 break;
 184         }
 185 }
 186
 187 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
 188 {
 189         ib_dealloc_pd(lnk->roce_pd);
 190         lnk->roce_pd = NULL;
 191 }
 192
 193 int smc_ib_create_protection_domain(struct smc_link *lnk)
 194 {
 195         int rc;
 196
 197         lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
 198         rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
 199         if (IS_ERR(lnk->roce_pd))
 200                 lnk->roce_pd = NULL;
 201         return rc;
 202 }
 203
 204 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 205 {
 206         switch (ibevent->event) {
 207         case IB_EVENT_DEVICE_FATAL:
 208         case IB_EVENT_GID_CHANGE:
 209         case IB_EVENT_PORT_ERR:
 210         case IB_EVENT_QP_ACCESS_ERR:
 211                 /* tbd in follow-on patch:
 212                  * abnormal close of corresponding connections
 213                  */
 214                 break;
 215         default:
 216                 break;
 217         }
 218 }
 219
 220 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
 221 {
 222         ib_destroy_qp(lnk->roce_qp);
 223         lnk->roce_qp = NULL;
 224 }
 225
 226 /* create a queue pair within the protection domain for a link */
 227 int smc_ib_create_queue_pair(struct smc_link *lnk)
 228 {
 229         struct ib_qp_init_attr qp_attr = {
 230                 .event_handler = smc_ib_qp_event_handler,
 231                 .qp_context = lnk,
 232                 .send_cq = lnk->smcibdev->roce_cq_send,
 233                 .recv_cq = lnk->smcibdev->roce_cq_recv,
 234                 .srq = NULL,
 235                 .cap = {
 236                                 /* include unsolicited rdma_writes as well,
 237                                  * there are max. 2 RDMA_WRITE per 1 WR_SEND
 238                                  */
 239                         .max_send_wr = SMC_WR_BUF_CNT * 3,
 240                         .max_recv_wr = SMC_WR_BUF_CNT * 3,
 241                         .max_send_sge = SMC_IB_MAX_SEND_SGE,
 242                         .max_recv_sge = 1,
 243                 },
 244                 .sq_sig_type = IB_SIGNAL_REQ_WR,
 245                 .qp_type = IB_QPT_RC,
 246         };
 247         int rc;
 248
 249         lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
 250         rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
 251         if (IS_ERR(lnk->roce_qp))
 252                 lnk->roce_qp = NULL;
 253         else
 254                 smc_wr_remember_qp_attr(lnk);
 255         return rc;
 256 }
 257
 258 void smc_ib_put_memory_region(struct ib_mr *mr)
 259 {
 260         ib_dereg_mr(mr);
 261 }
 262
 263 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
 264 {
 265         unsigned int offset = 0;
 266         int sg_num;
 267
 268         /* map the largest prefix of a dma mapped SG list */
 269         sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
 270                               buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 271                               buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 272                               &offset, PAGE_SIZE);
 273
 274         return sg_num;
 275 }
 276
 277 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
 278 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 279                              struct smc_buf_desc *buf_slot)
 280 {
 281         if (buf_slot->mr_rx[SMC_SINGLE_LINK])
 282                 return 0; /* already done */
 283
 284         buf_slot->mr_rx[SMC_SINGLE_LINK] =
 285                 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
 286         if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
 287                 int rc;
 288
 289                 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
 290                 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
 291                 return rc;
 292         }
 293
 294         if (smc_ib_map_mr_sg(buf_slot) != 1)
 295                 return -EINVAL;
 296
 297         return 0;
 298 }
 299
 300 /* synchronize buffer usage for cpu access */
 301 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
 302                             struct smc_buf_desc *buf_slot,
 303                             enum dma_data_direction data_direction)
 304 {
 305         struct scatterlist *sg;
 306         unsigned int i;
 307
 308         /* for now there is just one DMA address */
 309         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 310                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 311                 if (!sg_dma_len(sg))
 312                         break;
 313                 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
 314                                            sg_dma_address(sg),
 315                                            sg_dma_len(sg),
 316                                            data_direction);
 317         }
 318 }
 319
 320 /* synchronize buffer usage for device access */
 321 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
 322                                struct smc_buf_desc *buf_slot,
 323                                enum dma_data_direction data_direction)
 324 {
 325         struct scatterlist *sg;
 326         unsigned int i;
 327
 328         /* for now there is just one DMA address */
 329         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 330                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 331                 if (!sg_dma_len(sg))
 332                         break;
 333                 ib_dma_sync_single_for_device(smcibdev->ibdev,
 334                                               sg_dma_address(sg),
 335                                               sg_dma_len(sg),
 336                                               data_direction);
 337         }
 338 }
 339
 340 /* Map a new TX or RX buffer SG-table to DMA */
 341 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
 342                       struct smc_buf_desc *buf_slot,
 343                       enum dma_data_direction data_direction)
 344 {
 345         int mapped_nents;
 346
 347         mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
 348                                      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 349                                      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 350                                      data_direction);
 351         if (!mapped_nents)
 352                 return -ENOMEM;
 353
 354         return mapped_nents;
 355 }
 356
 357 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
 358                          struct smc_buf_desc *buf_slot,
 359                          enum dma_data_direction data_direction)
 360 {
 361         if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
 362                 return; /* already unmapped */
 363
 364         ib_dma_unmap_sg(smcibdev->ibdev,
 365                         buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 366                         buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 367                         data_direction);
 368         buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
 369 }
 370
 371 static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport)
 372 {
 373         struct net_device *ndev;
 374         int rc;
 375
 376         rc = ib_query_gid(smcibdev->ibdev, ibport, 0,
 377                           &smcibdev->gid[ibport - 1], NULL);
 378         /* the SMC protocol requires specification of the roce MAC address;
 379          * if net_device cannot be determined, it can be derived from gid 0
 380          */
 381         ndev = smcibdev->ibdev->get_netdev(smcibdev->ibdev, ibport);
 382         if (ndev) {
 383                 memcpy(&smcibdev->mac, ndev->dev_addr, ETH_ALEN);
 384                 dev_put(ndev);
 385         } else if (!rc) {
 386                 memcpy(&smcibdev->mac[ibport - 1][0],
 387                        &smcibdev->gid[ibport - 1].raw[8], 3);
 388                 memcpy(&smcibdev->mac[ibport - 1][3],
 389                        &smcibdev->gid[ibport - 1].raw[13], 3);
 390                 smcibdev->mac[ibport - 1][0] &= ~0x02;
 391         }
 392         return rc;
 393 }
 394
 395 /* Create an identifier unique for this instance of SMC-R.
 396  * The MAC-address of the first active registered IB device
 397  * plus a random 2-byte number is used to create this identifier.
 398  * This name is delivered to the peer during connection initialization.
 399  */
 400 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
 401                                                 u8 ibport)
 402 {
 403         memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
 404                sizeof(smcibdev->mac[ibport - 1]));
 405         get_random_bytes(&local_systemid[0], 2);
 406 }
 407
 408 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
 409 {
 410         return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
 411 }
 412
 413 int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 414 {
 415         int rc;
 416
 417         memset(&smcibdev->pattr[ibport - 1], 0,
 418                sizeof(smcibdev->pattr[ibport - 1]));
 419         rc = ib_query_port(smcibdev->ibdev, ibport,
 420                            &smcibdev->pattr[ibport - 1]);
 421         if (rc)
 422                 goto out;
 423         rc = smc_ib_fill_gid_and_mac(smcibdev, ibport);
 424         if (rc)
 425                 goto out;
 426         if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
 427                      sizeof(local_systemid)) &&
 428             smc_ib_port_active(smcibdev, ibport))
 429                 /* create unique system identifier */
 430                 smc_ib_define_local_systemid(smcibdev, ibport);
 431 out:
 432         return rc;
 433 }
 434
 435 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
 436 {
 437         struct ib_cq_init_attr cqattr = {
 438                 .cqe = SMC_WR_MAX_CQE, .comp_vector = 0 };
 439         long rc;
 440
 441         smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
 442                                               smc_wr_tx_cq_handler, NULL,
 443                                               smcibdev, &cqattr);
 444         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
 445         if (IS_ERR(smcibdev->roce_cq_send)) {
 446                 smcibdev->roce_cq_send = NULL;
 447                 return rc;
 448         }
 449         smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
 450                                               smc_wr_rx_cq_handler, NULL,
 451                                               smcibdev, &cqattr);
 452         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
 453         if (IS_ERR(smcibdev->roce_cq_recv)) {
 454                 smcibdev->roce_cq_recv = NULL;
 455                 goto err;
 456         }
 457         INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 458                               smc_ib_global_event_handler);
 459         ib_register_event_handler(&smcibdev->event_handler);
 460         smc_wr_add_dev(smcibdev);
 461         smcibdev->initialized = 1;
 462         return rc;
 463
 464 err:
 465         ib_destroy_cq(smcibdev->roce_cq_send);
 466         return rc;
 467 }
 468
 469 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 470 {
 471         if (!smcibdev->initialized)
 472                 return;
 473         smc_wr_remove_dev(smcibdev);
 474         ib_unregister_event_handler(&smcibdev->event_handler);
 475         ib_destroy_cq(smcibdev->roce_cq_recv);
 476         ib_destroy_cq(smcibdev->roce_cq_send);
 477 }
 478
 479 static struct ib_client smc_ib_client;
 480
 481 /* callback function for ib_register_client() */
 482 static void smc_ib_add_dev(struct ib_device *ibdev)
 483 {
 484         struct smc_ib_device *smcibdev;
 485
 486         if (ibdev->node_type != RDMA_NODE_IB_CA)
 487                 return;
 488
 489         smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
 490         if (!smcibdev)
 491                 return;
 492
 493         smcibdev->ibdev = ibdev;
 494         INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 495
 496         spin_lock(&smc_ib_devices.lock);
 497         list_add_tail(&smcibdev->list, &smc_ib_devices.list);
 498         spin_unlock(&smc_ib_devices.lock);
 499         ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 500 }
 501
 502 /* callback function for ib_register_client() */
 503 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 504 {
 505         struct smc_ib_device *smcibdev;
 506
 507         smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
 508         ib_set_client_data(ibdev, &smc_ib_client, NULL);
 509         spin_lock(&smc_ib_devices.lock);
 510         list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
 511         spin_unlock(&smc_ib_devices.lock);
 512         smc_pnet_remove_by_ibdev(smcibdev);
 513         smc_ib_cleanup_per_ibdev(smcibdev);
 514         kfree(smcibdev);
 515 }
 516
 517 static struct ib_client smc_ib_client = {
 518         .name   = "smc_ib",
 519         .add    = smc_ib_add_dev,
 520         .remove = smc_ib_remove_dev,
 521 };
 522
 523 int __init smc_ib_register_client(void)
 524 {
 525         return ib_register_client(&smc_ib_client);
 526 }
 527
 528 void smc_ib_unregister_client(void)
 529 {
 530         ib_unregister_client(&smc_ib_client);
 531 }