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 static void smc_ib_port_terminate(struct smc_ib_device *smcibdev, u8 ibport)
 145 {
 146         struct smc_link_group *lgr, *l;
 147
 148         list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) {
 149                 if (lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev &&
 150                     lgr->lnk[SMC_SINGLE_LINK].ibport == ibport)
 151                         smc_lgr_terminate(lgr);
 152         }
 153 }
 154
 155 /* process context wrapper for might_sleep smc_ib_remember_port_attr */
 156 static void smc_ib_port_event_work(struct work_struct *work)
 157 {
 158         struct smc_ib_device *smcibdev = container_of(
 159                 work, struct smc_ib_device, port_event_work);
 160         u8 port_idx;
 161
 162         for_each_set_bit(port_idx, &smcibdev->port_event_mask, SMC_MAX_PORTS) {
 163                 smc_ib_remember_port_attr(smcibdev, port_idx + 1);
 164                 clear_bit(port_idx, &smcibdev->port_event_mask);
 165                 if (!smc_ib_port_active(smcibdev, port_idx + 1))
 166                         smc_ib_port_terminate(smcibdev, port_idx + 1);
 167         }
 168 }
 169
 170 /* can be called in IRQ context */
 171 static void smc_ib_global_event_handler(struct ib_event_handler *handler,
 172                                         struct ib_event *ibevent)
 173 {
 174         struct smc_ib_device *smcibdev;
 175         u8 port_idx;
 176
 177         smcibdev = container_of(handler, struct smc_ib_device, event_handler);
 178
 179         switch (ibevent->event) {
 180         case IB_EVENT_PORT_ERR:
 181         case IB_EVENT_DEVICE_FATAL:
 182         case IB_EVENT_PORT_ACTIVE:
 183                 port_idx = ibevent->element.port_num - 1;
 184                 set_bit(port_idx, &smcibdev->port_event_mask);
 185                 schedule_work(&smcibdev->port_event_work);
 186                 break;
 187         default:
 188                 break;
 189         }
 190 }
 191
 192 void smc_ib_dealloc_protection_domain(struct smc_link *lnk)
 193 {
 194         if (lnk->roce_pd)
 195                 ib_dealloc_pd(lnk->roce_pd);
 196         lnk->roce_pd = NULL;
 197 }
 198
 199 int smc_ib_create_protection_domain(struct smc_link *lnk)
 200 {
 201         int rc;
 202
 203         lnk->roce_pd = ib_alloc_pd(lnk->smcibdev->ibdev, 0);
 204         rc = PTR_ERR_OR_ZERO(lnk->roce_pd);
 205         if (IS_ERR(lnk->roce_pd))
 206                 lnk->roce_pd = NULL;
 207         return rc;
 208 }
 209
 210 static void smc_ib_qp_event_handler(struct ib_event *ibevent, void *priv)
 211 {
 212         struct smc_ib_device *smcibdev =
 213                 (struct smc_ib_device *)ibevent->device;
 214         u8 port_idx;
 215
 216         switch (ibevent->event) {
 217         case IB_EVENT_DEVICE_FATAL:
 218         case IB_EVENT_GID_CHANGE:
 219         case IB_EVENT_PORT_ERR:
 220         case IB_EVENT_QP_ACCESS_ERR:
 221                 port_idx = ibevent->element.port_num - 1;
 222                 set_bit(port_idx, &smcibdev->port_event_mask);
 223                 schedule_work(&smcibdev->port_event_work);
 224                 break;
 225         default:
 226                 break;
 227         }
 228 }
 229
 230 void smc_ib_destroy_queue_pair(struct smc_link *lnk)
 231 {
 232         if (lnk->roce_qp)
 233                 ib_destroy_qp(lnk->roce_qp);
 234         lnk->roce_qp = NULL;
 235 }
 236
 237 /* create a queue pair within the protection domain for a link */
 238 int smc_ib_create_queue_pair(struct smc_link *lnk)
 239 {
 240         struct ib_qp_init_attr qp_attr = {
 241                 .event_handler = smc_ib_qp_event_handler,
 242                 .qp_context = lnk,
 243                 .send_cq = lnk->smcibdev->roce_cq_send,
 244                 .recv_cq = lnk->smcibdev->roce_cq_recv,
 245                 .srq = NULL,
 246                 .cap = {
 247                                 /* include unsolicited rdma_writes as well,
 248                                  * there are max. 2 RDMA_WRITE per 1 WR_SEND
 249                                  */
 250                         .max_send_wr = SMC_WR_BUF_CNT * 3,
 251                         .max_recv_wr = SMC_WR_BUF_CNT * 3,
 252                         .max_send_sge = SMC_IB_MAX_SEND_SGE,
 253                         .max_recv_sge = 1,
 254                 },
 255                 .sq_sig_type = IB_SIGNAL_REQ_WR,
 256                 .qp_type = IB_QPT_RC,
 257         };
 258         int rc;
 259
 260         lnk->roce_qp = ib_create_qp(lnk->roce_pd, &qp_attr);
 261         rc = PTR_ERR_OR_ZERO(lnk->roce_qp);
 262         if (IS_ERR(lnk->roce_qp))
 263                 lnk->roce_qp = NULL;
 264         else
 265                 smc_wr_remember_qp_attr(lnk);
 266         return rc;
 267 }
 268
 269 void smc_ib_put_memory_region(struct ib_mr *mr)
 270 {
 271         ib_dereg_mr(mr);
 272 }
 273
 274 static int smc_ib_map_mr_sg(struct smc_buf_desc *buf_slot)
 275 {
 276         unsigned int offset = 0;
 277         int sg_num;
 278
 279         /* map the largest prefix of a dma mapped SG list */
 280         sg_num = ib_map_mr_sg(buf_slot->mr_rx[SMC_SINGLE_LINK],
 281                               buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 282                               buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 283                               &offset, PAGE_SIZE);
 284
 285         return sg_num;
 286 }
 287
 288 /* Allocate a memory region and map the dma mapped SG list of buf_slot */
 289 int smc_ib_get_memory_region(struct ib_pd *pd, int access_flags,
 290                              struct smc_buf_desc *buf_slot)
 291 {
 292         if (buf_slot->mr_rx[SMC_SINGLE_LINK])
 293                 return 0; /* already done */
 294
 295         buf_slot->mr_rx[SMC_SINGLE_LINK] =
 296                 ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG, 1 << buf_slot->order);
 297         if (IS_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK])) {
 298                 int rc;
 299
 300                 rc = PTR_ERR(buf_slot->mr_rx[SMC_SINGLE_LINK]);
 301                 buf_slot->mr_rx[SMC_SINGLE_LINK] = NULL;
 302                 return rc;
 303         }
 304
 305         if (smc_ib_map_mr_sg(buf_slot) != 1)
 306                 return -EINVAL;
 307
 308         return 0;
 309 }
 310
 311 /* synchronize buffer usage for cpu access */
 312 void smc_ib_sync_sg_for_cpu(struct smc_ib_device *smcibdev,
 313                             struct smc_buf_desc *buf_slot,
 314                             enum dma_data_direction data_direction)
 315 {
 316         struct scatterlist *sg;
 317         unsigned int i;
 318
 319         /* for now there is just one DMA address */
 320         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 321                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 322                 if (!sg_dma_len(sg))
 323                         break;
 324                 ib_dma_sync_single_for_cpu(smcibdev->ibdev,
 325                                            sg_dma_address(sg),
 326                                            sg_dma_len(sg),
 327                                            data_direction);
 328         }
 329 }
 330
 331 /* synchronize buffer usage for device access */
 332 void smc_ib_sync_sg_for_device(struct smc_ib_device *smcibdev,
 333                                struct smc_buf_desc *buf_slot,
 334                                enum dma_data_direction data_direction)
 335 {
 336         struct scatterlist *sg;
 337         unsigned int i;
 338
 339         /* for now there is just one DMA address */
 340         for_each_sg(buf_slot->sgt[SMC_SINGLE_LINK].sgl, sg,
 341                     buf_slot->sgt[SMC_SINGLE_LINK].nents, i) {
 342                 if (!sg_dma_len(sg))
 343                         break;
 344                 ib_dma_sync_single_for_device(smcibdev->ibdev,
 345                                               sg_dma_address(sg),
 346                                               sg_dma_len(sg),
 347                                               data_direction);
 348         }
 349 }
 350
 351 /* Map a new TX or RX buffer SG-table to DMA */
 352 int smc_ib_buf_map_sg(struct smc_ib_device *smcibdev,
 353                       struct smc_buf_desc *buf_slot,
 354                       enum dma_data_direction data_direction)
 355 {
 356         int mapped_nents;
 357
 358         mapped_nents = ib_dma_map_sg(smcibdev->ibdev,
 359                                      buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 360                                      buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 361                                      data_direction);
 362         if (!mapped_nents)
 363                 return -ENOMEM;
 364
 365         return mapped_nents;
 366 }
 367
 368 void smc_ib_buf_unmap_sg(struct smc_ib_device *smcibdev,
 369                          struct smc_buf_desc *buf_slot,
 370                          enum dma_data_direction data_direction)
 371 {
 372         if (!buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address)
 373                 return; /* already unmapped */
 374
 375         ib_dma_unmap_sg(smcibdev->ibdev,
 376                         buf_slot->sgt[SMC_SINGLE_LINK].sgl,
 377                         buf_slot->sgt[SMC_SINGLE_LINK].orig_nents,
 378                         data_direction);
 379         buf_slot->sgt[SMC_SINGLE_LINK].sgl->dma_address = 0;
 380 }
 381
 382 static int smc_ib_fill_gid_and_mac(struct smc_ib_device *smcibdev, u8 ibport)
 383 {
 384         struct ib_gid_attr gattr;
 385         int rc;
 386
 387         rc = ib_query_gid(smcibdev->ibdev, ibport, 0,
 388                           &smcibdev->gid[ibport - 1], &gattr);
 389         if (rc || !gattr.ndev)
 390                 return -ENODEV;
 391
 392         memcpy(smcibdev->mac[ibport - 1], gattr.ndev->dev_addr, ETH_ALEN);
 393         dev_put(gattr.ndev);
 394         return 0;
 395 }
 396
 397 /* Create an identifier unique for this instance of SMC-R.
 398  * The MAC-address of the first active registered IB device
 399  * plus a random 2-byte number is used to create this identifier.
 400  * This name is delivered to the peer during connection initialization.
 401  */
 402 static inline void smc_ib_define_local_systemid(struct smc_ib_device *smcibdev,
 403                                                 u8 ibport)
 404 {
 405         memcpy(&local_systemid[2], &smcibdev->mac[ibport - 1],
 406                sizeof(smcibdev->mac[ibport - 1]));
 407         get_random_bytes(&local_systemid[0], 2);
 408 }
 409
 410 bool smc_ib_port_active(struct smc_ib_device *smcibdev, u8 ibport)
 411 {
 412         return smcibdev->pattr[ibport - 1].state == IB_PORT_ACTIVE;
 413 }
 414
 415 int smc_ib_remember_port_attr(struct smc_ib_device *smcibdev, u8 ibport)
 416 {
 417         int rc;
 418
 419         memset(&smcibdev->pattr[ibport - 1], 0,
 420                sizeof(smcibdev->pattr[ibport - 1]));
 421         rc = ib_query_port(smcibdev->ibdev, ibport,
 422                            &smcibdev->pattr[ibport - 1]);
 423         if (rc)
 424                 goto out;
 425         /* the SMC protocol requires specification of the RoCE MAC address */
 426         rc = smc_ib_fill_gid_and_mac(smcibdev, ibport);
 427         if (rc)
 428                 goto out;
 429         if (!strncmp(local_systemid, SMC_LOCAL_SYSTEMID_RESET,
 430                      sizeof(local_systemid)) &&
 431             smc_ib_port_active(smcibdev, ibport))
 432                 /* create unique system identifier */
 433                 smc_ib_define_local_systemid(smcibdev, ibport);
 434 out:
 435         return rc;
 436 }
 437
 438 long smc_ib_setup_per_ibdev(struct smc_ib_device *smcibdev)
 439 {
 440         struct ib_cq_init_attr cqattr = {
 441                 .cqe = SMC_WR_MAX_CQE, .comp_vector = 0 };
 442         long rc;
 443
 444         smcibdev->roce_cq_send = ib_create_cq(smcibdev->ibdev,
 445                                               smc_wr_tx_cq_handler, NULL,
 446                                               smcibdev, &cqattr);
 447         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_send);
 448         if (IS_ERR(smcibdev->roce_cq_send)) {
 449                 smcibdev->roce_cq_send = NULL;
 450                 return rc;
 451         }
 452         smcibdev->roce_cq_recv = ib_create_cq(smcibdev->ibdev,
 453                                               smc_wr_rx_cq_handler, NULL,
 454                                               smcibdev, &cqattr);
 455         rc = PTR_ERR_OR_ZERO(smcibdev->roce_cq_recv);
 456         if (IS_ERR(smcibdev->roce_cq_recv)) {
 457                 smcibdev->roce_cq_recv = NULL;
 458                 goto err;
 459         }
 460         INIT_IB_EVENT_HANDLER(&smcibdev->event_handler, smcibdev->ibdev,
 461                               smc_ib_global_event_handler);
 462         ib_register_event_handler(&smcibdev->event_handler);
 463         smc_wr_add_dev(smcibdev);
 464         smcibdev->initialized = 1;
 465         return rc;
 466
 467 err:
 468         ib_destroy_cq(smcibdev->roce_cq_send);
 469         return rc;
 470 }
 471
 472 static void smc_ib_cleanup_per_ibdev(struct smc_ib_device *smcibdev)
 473 {
 474         if (!smcibdev->initialized)
 475                 return;
 476         smcibdev->initialized = 0;
 477         smc_wr_remove_dev(smcibdev);
 478         ib_unregister_event_handler(&smcibdev->event_handler);
 479         ib_destroy_cq(smcibdev->roce_cq_recv);
 480         ib_destroy_cq(smcibdev->roce_cq_send);
 481 }
 482
 483 static struct ib_client smc_ib_client;
 484
 485 /* callback function for ib_register_client() */
 486 static void smc_ib_add_dev(struct ib_device *ibdev)
 487 {
 488         struct smc_ib_device *smcibdev;
 489
 490         if (ibdev->node_type != RDMA_NODE_IB_CA)
 491                 return;
 492
 493         smcibdev = kzalloc(sizeof(*smcibdev), GFP_KERNEL);
 494         if (!smcibdev)
 495                 return;
 496
 497         smcibdev->ibdev = ibdev;
 498         INIT_WORK(&smcibdev->port_event_work, smc_ib_port_event_work);
 499
 500         spin_lock(&smc_ib_devices.lock);
 501         list_add_tail(&smcibdev->list, &smc_ib_devices.list);
 502         spin_unlock(&smc_ib_devices.lock);
 503         ib_set_client_data(ibdev, &smc_ib_client, smcibdev);
 504 }
 505
 506 /* callback function for ib_register_client() */
 507 static void smc_ib_remove_dev(struct ib_device *ibdev, void *client_data)
 508 {
 509         struct smc_ib_device *smcibdev;
 510
 511         smcibdev = ib_get_client_data(ibdev, &smc_ib_client);
 512         ib_set_client_data(ibdev, &smc_ib_client, NULL);
 513         spin_lock(&smc_ib_devices.lock);
 514         list_del_init(&smcibdev->list); /* remove from smc_ib_devices */
 515         spin_unlock(&smc_ib_devices.lock);
 516         smc_pnet_remove_by_ibdev(smcibdev);
 517         smc_ib_cleanup_per_ibdev(smcibdev);
 518         kfree(smcibdev);
 519 }
 520
 521 static struct ib_client smc_ib_client = {
 522         .name   = "smc_ib",
 523         .add    = smc_ib_add_dev,
 524         .remove = smc_ib_remove_dev,
 525 };
 526
 527 int __init smc_ib_register_client(void)
 528 {
 529         return ib_register_client(&smc_ib_client);
 530 }
 531
 532 void smc_ib_unregister_client(void)
 533 {
 534         ib_unregister_client(&smc_ib_client);
 535 }