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_MAX_CQE 32766       /* max. # of completion queue elements */
  27
  28 #define SMC_QP_MIN_RNR_TIMER            5
  29 #define SMC_QP_TIMEOUT                  15 /* 4096 * 2 ** timeout usec */
  30 #define SMC_QP_RETRY_CNT                        7 /* 7: infinite */
  31 #define SMC_QP_RNR_RETRY                        7 /* 7: infinite */
  32
  33 struct smc_ib_devices smc_ib_devices = {        /* smc-registered ib devices */
  34         .lock = __SPIN_LOCK_UNLOCKED(smc_ib_devices.lock),
  35         .list = LIST_HEAD_INIT(smc_ib_devices.list),
  36 };
  37
  38 #define SMC_LOCAL_SYSTEMID_RESET        "%%%%%%%"
  39
  40 u8 local_systemid[SMC_SYSTEMID_LEN] = SMC_LOCAL_SYSTEMID_RESET; /* unique system
  41                                                                  * identifier
  42                                                                  */
  43
  44 static int smc_ib_modify_qp_init(struct smc_link *lnk)
  45 {
  46         struct ib_qp_attr qp_attr;
  47
  48         memset(&qp_attr, 0, sizeof(qp_attr));
  49         qp_attr.qp_state = IB_QPS_INIT;
  50         qp_attr.pkey_index = 0;
  51         qp_attr.port_num = lnk->ibport;
  52         qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE
  53                                 | IB_ACCESS_REMOTE_WRITE;
  54         return ib_modify_qp(lnk->roce_qp, &qp_attr,
  55                             IB_QP_STATE | IB_QP_PKEY_INDEX |
  56                             IB_QP_ACCESS_FLAGS | IB_QP_PORT);
  57 }
  58
  59 static int smc_ib_modify_qp_rtr(struct smc_link *lnk)
  60 {
  61         enum ib_qp_attr_mask qp_attr_mask =
  62                 IB_QP_STATE | IB_QP_AV | IB_QP_PATH_MTU | IB_QP_DEST_QPN |
  63                 IB_QP_RQ_PSN | IB_QP_MAX_DEST_RD_ATOMIC | IB_QP_MIN_RNR_TIMER;
  64         struct ib_qp_attr qp_attr;
  65
  66         memset(&qp_attr, 0, sizeof(qp_attr));
  67         qp_attr.qp_state = IB_QPS_RTR;
  68         qp_attr.path_mtu = min(lnk->path_mtu, lnk->peer_mtu);
  69         qp_attr.ah_attr.type = RDMA_AH_ATTR_TYPE_ROCE;
  70         rdma_ah_set_port_num(&qp_attr.ah_attr, lnk->ibport);
  71         rdma_ah_set_grh(&qp_attr.ah_attr, NULL, 0, 0, 1, 0);
  72         rdma_ah_set_dgid_raw(&qp_attr.ah_attr, lnk->peer_gid);
  73         memcpy(&qp_attr.ah_attr.roce.dmac, lnk->peer_mac,
  74                sizeof(lnk->peer_mac));
  75         qp_attr.dest_qp_num = lnk->peer_qpn;
  76         qp_attr.rq_psn = lnk->peer_psn; /* starting receive packet seq # */
  77         qp_attr.max_dest_rd_atomic = 1; /* max # of resources for incoming
  78                                          * requests
  79                                          */
  80         qp_attr.min_rnr_timer = SMC_QP_MIN_RNR_TIMER;
  81
  82         return ib_modify_qp(lnk->roce_qp, &qp_attr, qp_attr_mask);
  83 }
  84
  85 int smc_ib_modify_qp_rts(struct smc_link *lnk)
  86 {
  87         struct ib_qp_attr qp_attr;
  88
  89         memset(&qp_attr, 0, sizeof(qp_attr));
  90         qp_attr.qp_state = IB_QPS_RTS;
  91         qp_attr.timeout = SMC_QP_TIMEOUT;       /* local ack timeout */
  92         qp_attr.retry_cnt = SMC_QP_RETRY_CNT;   /* retry count */
  93         qp_attr.rnr_retry = SMC_QP_RNR_RETRY;   /* RNR retries, 7=infinite */
  94         qp_attr.sq_psn = lnk->psn_initial;      /* starting send packet seq # */
  95         qp_attr.max_rd_atomic = 1;      /* # of outstanding RDMA reads and
  96                                          * atomic ops allowed
  97                                          */
  98         return ib_modify_qp(lnk->roce_qp, &qp_attr,
  99                             IB_QP_STATE | IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
 100                             IB_QP_SQ_PSN | IB_QP_RNR_RETRY |
 101                             IB_QP_MAX_QP_RD_ATOMIC);
 102 }
 103
 104 int smc_ib_modify_qp_reset(struct smc_link *lnk)
 105 {
 106         struct ib_qp_attr qp_attr;
 107
 108         memset(&qp_attr, 0, sizeof(qp_attr));
 109         qp_attr.qp_state = IB_QPS_RESET;
 110         return ib_modify_qp(lnk->roce_qp, &qp_attr, IB_QP_STATE);
 111 }
 112
 113 int smc_ib_ready_link(struct smc_link *lnk)
 114 {
 115         struct smc_link_group *lgr =
 116                 container_of(lnk, struct smc_link_group, lnk[0]);
 117         int rc = 0;
 118
 119         rc = smc_ib_modify_qp_init(lnk);
 120         if (rc)
 121                 goto out;
 122
 123         rc = smc_ib_modify_qp_rtr(lnk);
 124         if (rc)
 125                 goto out;
 126         smc_wr_remember_qp_attr(lnk);
 127         rc = ib_req_notify_cq(lnk->smcibdev->roce_cq_recv,
 128                               IB_CQ_SOLICITED_MASK);
 129         if (rc)
 130                 goto out;
 131         rc = smc_wr_rx_post_init(lnk);
 132         if (rc)
 133                 goto out;
 134         smc_wr_remember_qp_attr(lnk);
 135
 136         if (lgr->role == SMC_SERV) {
 137                 rc = smc_ib_modify_qp_rts(lnk);
 138                 if (rc)
 139                         goto out;
 140                 smc_wr_remember_qp_attr(lnk);
 141         }
 142 out:
 143         return rc;
 144 }
 145
 146 static void smc_ib_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 147 {
 148         struct smc_link_group *lgr, *l;
 149
 150         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 151                 if (lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 152                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
 153                         smc_lgr_terminate(lgr);
 154         }
 155 }
 156
 157 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
 158 static void smc_ib_port_event_work(struct work_struct *work)
 159 {
 160         struct smc_ib_device *smcibdev = container_of(
 161                 work, struct smc_ib_device, port_event_work);
 162         u8 port_idx;
 163
 164         for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
 165                 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
 166                 clear_bit(port_idx, &smcibdev->port_event_mask);
 167                 if (!smc_ib_port_active(smcibdev, port_idx + 1))
 168                         smc_ib_port_terminate(smcibdev, port_idx + 1);
 169         }
 170 }
 171
 172 /* can be called in IRQ context */
 173 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 174                                         struct ib_event *ibevent)
 175 {
 176         struct smc_ib_device *smcibdev;
 177         u8 port_idx;
 178
 179         smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 180
 181         switch (ibevent->event) {
 182         case IB_EVENT_PORT_ERR:
 183         case IB_EVENT_DEVICE_FATAL:
 184         case IB_EVENT_PORT_ACTIVE:
 185                 port_idx = ibevent->element.port_num - 1;
 186                 set_bit(port_idx, &smcibdev->port_event_mask);
 187                 schedule_work(&smcibdev->port_event_work);
 188                 break;
 189         default:
 190                 break;
 191         }
 192 }
 193
 194 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
 195 {
 196         if (lnk->roce_pd)
 197                 ib_dealloc_pd(lnk->roce_pd);
 198         lnk->roce_pd = NULL;
 199 }
 200
 201 int smc_ib_create_protection_domain(struct smc_link *lnk)
 202 {
 203         int rc;
 204
 205         lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
 206         rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
 207         if (IS_ERR(lnk->roce_pd))
 208                 lnk->roce_pd = NULL;
 209         return rc;
 210 }
 211
 212 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 213 {
 214         struct smc_ib_device *smcibdev =
 215                 (struct smc_ib_device *)ibevent->device;
 216         u8 port_idx;
 217
 218         switch (ibevent->event) {
 219         case IB_EVENT_DEVICE_FATAL:
 220         case IB_EVENT_GID_CHANGE:
 221         case IB_EVENT_PORT_ERR:
 222         case IB_EVENT_QP_ACCESS_ERR:
 223                 port_idx = ibevent->element.port_num - 1;
 224                 set_bit(port_idx, &smcibdev->port_event_mask);
 225                 schedule_work(&smcibdev->port_event_work);
 226                 break;
 227         default:
 228                 break;
 229         }
 230 }
 231
 232 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
 233 {
 234         if (lnk->roce_qp)
 235                 ib_destroy_qp(lnk->roce_qp);
 236         lnk->roce_qp = NULL;
 237 }
 238
 239 /* create a queue pair within the protection domain for a link */
 240 int smc_ib_create_queue_pair(struct smc_link *lnk)
 241 {
 242         struct ib_qp_init_attr qp_attr = {
 243                 .event_handler = smc_ib_qp_event_handler,
 244                 .qp_context = lnk,
 245                 .send_cq = lnk->smcibdev->roce_cq_send,
 246                 .recv_cq = lnk->smcibdev->roce_cq_recv,
 247                 .srq = NULL,
 248                 .cap = {
 249                                 /* include unsolicited rdma_writes as well,
 250                                  * there are max. 2 RDMA_WRITE per 1 WR_SEND
 251                                  */
 252                         .max_send_wr = SMC_WR_BUF_CNT * 3,
 253                         .max_recv_wr = SMC_WR_BUF_CNT * 3,
 254                         .max_send_sge = SMC_IB_MAX_SEND_SGE,
 255                         .max_recv_sge = 1,
 256                 },
 257                 .sq_sig_type = IB_SIGNAL_REQ_WR,
 258                 .qp_type = IB_QPT_RC,
 259         };
 260         int rc;
 261
 262         lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
 263         rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
 264         if (IS_ERR(lnk->roce_qp))
 265                 lnk->roce_qp = NULL;
 266         else
 267                 smc_wr_remember_qp_attr(lnk);
 268         return rc;
 269 }
 270
 271 void smc_ib_put_memory_region(struct ib_mr *mr)
 272 {
 273         ib_dereg_mr(mr);
 274 }
 275
 276 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
 277 {
 278         unsigned int offset = 0;
 279         int sg_num;
 280
 281         /* map the largest prefix of a dma mapped SG list */
 282         sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
 283                               buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 284                               buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 285                               &offset, PAGE_SIZE);
 286
 287         return sg_num;
 288 }
 289
 290 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
 291 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 292                              struct smc_buf_desc *buf_slot)
 293 {
 294         if (buf_slot->mr_rx[SMC_SINGLE_LINK])
 295                 return 0; /* already done */
 296
 297         buf_slot->mr_rx[SMC_SINGLE_LINK] =
 298                 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
 299         if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
 300                 int rc;
 301
 302                 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
 303                 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
 304                 return rc;
 305         }
 306
 307         if (smc_ib_map_mr_sg(buf_slot) != 1)
 308                 return -EINVAL;
 309
 310         return 0;
 311 }
 312
 313 /* synchronize buffer usage for cpu access */
 314 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
 315                             struct smc_buf_desc *buf_slot,
 316                             enum dma_data_direction data_direction)
 317 {
 318         struct scatterlist *sg;
 319         unsigned int i;
 320
 321         /* for now there is just one DMA address */
 322         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 323                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 324                 if (!sg_dma_len(sg))
 325                         break;
 326                 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
 327                                            sg_dma_address(sg),
 328                                            sg_dma_len(sg),
 329                                            data_direction);
 330         }
 331 }
 332
 333 /* synchronize buffer usage for device access */
 334 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
 335                                struct smc_buf_desc *buf_slot,
 336                                enum dma_data_direction data_direction)
 337 {
 338         struct scatterlist *sg;
 339         unsigned int i;
 340
 341         /* for now there is just one DMA address */
 342         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 343                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 344                 if (!sg_dma_len(sg))
 345                         break;
 346                 ib_dma_sync_single_for_device(smcibdev->ibdev,
 347                                               sg_dma_address(sg),
 348                                               sg_dma_len(sg),
 349                                               data_direction);
 350         }
 351 }
 352
 353 /* Map a new TX or RX buffer SG-table to DMA */
 354 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
 355                       struct smc_buf_desc *buf_slot,
 356                       enum dma_data_direction data_direction)
 357 {
 358         int mapped_nents;
 359
 360         mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
 361                                      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 362                                      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 363                                      data_direction);
 364         if (!mapped_nents)
 365                 return -ENOMEM;
 366
 367         return mapped_nents;
 368 }
 369
 370 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
 371                          struct smc_buf_desc *buf_slot,
 372                          enum dma_data_direction data_direction)
 373 {
 374         if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
 375                 return; /* already unmapped */
 376
 377         ib_dma_unmap_sg(smcibdev->ibdev,
 378                         buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 379                         buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 380                         data_direction);
 381         buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
 382 }
 383
 384 static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport)
 385 {
 386         struct ib_gid_attr gattr;
 387         int rc;
 388
 389         rc = ib_query_gid(smcibdev->ibdev, ibport, 0,
 390                           &smcibdev->gid[ibport - 1], &gattr);
 391         if (rc || !gattr.ndev)
 392                 return -ENODEV;
 393
 394         memcpy(smcibdev->mac[ibport - 1], gattr.ndev->dev_addr, ETH_ALEN);
 395         dev_put(gattr.ndev);
 396         return 0;
 397 }
 398
 399 /* Create an identifier unique for this instance of SMC-R.
 400  * The MAC-address of the first active registered IB device
 401  * plus a random 2-byte number is used to create this identifier.
 402  * This name is delivered to the peer during connection initialization.
 403  */
 404 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
 405                                                 u8 ibport)
 406 {
 407         memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
 408                sizeof(smcibdev->mac[ibport - 1]));
 409         get_random_bytes(&local_systemid[0], 2);
 410 }
 411
 412 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
 413 {
 414         return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
 415 }
 416
 417 int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 418 {
 419         int rc;
 420
 421         memset(&smcibdev->pattr[ibport - 1], 0,
 422                sizeof(smcibdev->pattr[ibport - 1]));
 423         rc = ib_query_port(smcibdev->ibdev, ibport,
 424                            &smcibdev->pattr[ibport - 1]);
 425         if (rc)
 426                 goto out;
 427         /* the SMC protocol requires specification of the RoCE MAC address */
 428         rc = smc_ib_fill_gid_and_mac(smcibdev, ibport);
 429         if (rc)
 430                 goto out;
 431         if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
 432                      sizeof(local_systemid)) &&
 433             smc_ib_port_active(smcibdev, ibport))
 434                 /* create unique system identifier */
 435                 smc_ib_define_local_systemid(smcibdev, ibport);
 436 out:
 437         return rc;
 438 }
 439
 440 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
 441 {
 442         struct ib_cq_init_attr cqattr = {
 443                 .cqe = SMC_MAX_CQE, .comp_vector = 0 };
 444         int cqe_size_order, smc_order;
 445         long rc;
 446
 447         /* the calculated number of cq entries fits to mlx5 cq allocation */
 448         cqe_size_order = cache_line_size() == 128 ? 7 : 6;
 449         smc_order = MAX_ORDER - cqe_size_order - 1;
 450         if (SMC_MAX_CQE + 2 > (0x00000001 << smc_order) * PAGE_SIZE)
 451                 cqattr.cqe = (0x00000001 << smc_order) * PAGE_SIZE - 2;
 452         smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
 453                                               smc_wr_tx_cq_handler, NULL,
 454                                               smcibdev, &cqattr);
 455         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
 456         if (IS_ERR(smcibdev->roce_cq_send)) {
 457                 smcibdev->roce_cq_send = NULL;
 458                 return rc;
 459         }
 460         smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
 461                                               smc_wr_rx_cq_handler, NULL,
 462                                               smcibdev, &cqattr);
 463         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
 464         if (IS_ERR(smcibdev->roce_cq_recv)) {
 465                 smcibdev->roce_cq_recv = NULL;
 466                 goto err;
 467         }
 468         INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 469                               smc_ib_global_event_handler);
 470         ib_register_event_handler(&smcibdev->event_handler);
 471         smc_wr_add_dev(smcibdev);
 472         smcibdev->initialized = 1;
 473         return rc;
 474
 475 err:
 476         ib_destroy_cq(smcibdev->roce_cq_send);
 477         return rc;
 478 }
 479
 480 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 481 {
 482         if (!smcibdev->initialized)
 483                 return;
 484         smcibdev->initialized = 0;
 485         smc_wr_remove_dev(smcibdev);
 486         ib_unregister_event_handler(&smcibdev->event_handler);
 487         ib_destroy_cq(smcibdev->roce_cq_recv);
 488         ib_destroy_cq(smcibdev->roce_cq_send);
 489 }
 490
 491 static struct ib_client smc_ib_client;
 492
 493 /* callback function for ib_register_client() */
 494 static void smc_ib_add_dev(struct ib_device *ibdev)
 495 {
 496         struct smc_ib_device *smcibdev;
 497
 498         if (ibdev->node_type != RDMA_NODE_IB_CA)
 499                 return;
 500
 501         smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
 502         if (!smcibdev)
 503                 return;
 504
 505         smcibdev->ibdev = ibdev;
 506         INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 507
 508         spin_lock(&smc_ib_devices.lock);
 509         list_add_tail(&smcibdev->list, &smc_ib_devices.list);
 510         spin_unlock(&smc_ib_devices.lock);
 511         ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 512 }
 513
 514 /* callback function for ib_register_client() */
 515 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 516 {
 517         struct smc_ib_device *smcibdev;
 518
 519         smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
 520         ib_set_client_data(ibdev, &smc_ib_client, NULL);
 521         spin_lock(&smc_ib_devices.lock);
 522         list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
 523         spin_unlock(&smc_ib_devices.lock);
 524         smc_pnet_remove_by_ibdev(smcibdev);
 525         smc_ib_cleanup_per_ibdev(smcibdev);
 526         kfree(smcibdev);
 527 }
 528
 529 static struct ib_client smc_ib_client = {
 530         .name   = "smc_ib",
 531         .add    = smc_ib_add_dev,
 532         .remove = smc_ib_remove_dev,
 533 };
 534
 535 int __init smc_ib_register_client(void)
 536 {
 537         return ib_register_client(&smc_ib_client);
 538 }
 539
 540 void smc_ib_unregister_client(void)
 541 {
 542         ib_unregister_client(&smc_ib_client);
 543 }