net/smc/smc_wr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Shared Memory Communications over RDMA (SMC-R) and RoCE
   4  *
   5  * Work Requests exploiting Infiniband API
   6  *
   7  * Work requests (WR) of type ib_post_send or ib_post_recv respectively
   8  * are submitted to either RC SQ or RC RQ respectively
   9  * (reliably connected send/receive queue)
  10  * and become work queue entries (WQEs).
  11  * While an SQ WR/WQE is pending, we track it until transmission completion.
  12  * Through a send or receive completion queue (CQ) respectively,
  13  * we get completion queue entries (CQEs) [aka work completions (WCs)].
  14  * Since the CQ callback is called from IRQ context, we split work by using
  15  * bottom halves implemented by tasklets.
  16  *
  17  * SMC uses this to exchange LLC (link layer control)
  18  * and CDC (connection data control) messages.
  19  *
  20  * Copyright IBM Corp. 2016
  21  *
  22  * Author(s):  Steffen Maier <maier@linux.vnet.ibm.com>
  23  */
  24
  25 #include <linux/atomic.h>
  26 #include <linux/hashtable.h>
  27 #include <linux/wait.h>
  28 #include <rdma/ib_verbs.h>
  29 #include <asm/div64.h>
  30
  31 #include "smc.h"
  32 #include "smc_wr.h"
  33
  34 #define SMC_WR_MAX_POLL_CQE 10  /* max. # of compl. queue elements in 1 poll */
  35
  36 #define SMC_WR_RX_HASH_BITS 4
  37 static DEFINE_HASHTABLE(smc_wr_rx_hash, SMC_WR_RX_HASH_BITS);
  38 static DEFINE_SPINLOCK(smc_wr_rx_hash_lock);
  39
  40 struct smc_wr_tx_pend { /* control data for a pending send request */
  41         u64                     wr_id;          /* work request id sent */
  42         smc_wr_tx_handler       handler;
  43         enum ib_wc_status       wc_status;      /* CQE status */
  44         struct smc_link         *link;
  45         u32                     idx;
  46         struct smc_wr_tx_pend_priv priv;
  47 };
  48
  49 /******************************** send queue *********************************/
  50
  51 /*------------------------------- completion --------------------------------*/
  52
  53 static inline int smc_wr_tx_find_pending_index(struct smc_link *link, u64 wr_id)
  54 {
  55         u32 i;
  56
  57         for (i = 0; i < link->wr_tx_cnt; i++) {
  58                 if (link->wr_tx_pends[i].wr_id == wr_id)
  59                         return i;
  60         }
  61         return link->wr_tx_cnt;
  62 }
  63
  64 static inline void smc_wr_tx_process_cqe(struct ib_wc *wc)
  65 {
  66         struct smc_wr_tx_pend pnd_snd;
  67         struct smc_link *link;
  68         u32 pnd_snd_idx;
  69         int i;
  70
  71         link = wc->qp->qp_context;
  72
  73         if (wc->opcode == IB_WC_REG_MR) {
  74                 if (wc->status)
  75                         link->wr_reg_state = FAILED;
  76                 else
  77                         link->wr_reg_state = CONFIRMED;
  78                 wake_up(&link->wr_reg_wait);
  79                 return;
  80         }
  81
  82         pnd_snd_idx = smc_wr_tx_find_pending_index(link, wc->wr_id);
  83         if (pnd_snd_idx == link->wr_tx_cnt)
  84                 return;
  85         link->wr_tx_pends[pnd_snd_idx].wc_status = wc->status;
  86         memcpy(&pnd_snd, &link->wr_tx_pends[pnd_snd_idx], sizeof(pnd_snd));
  87         /* clear the full struct smc_wr_tx_pend including .priv */
  88         memset(&link->wr_tx_pends[pnd_snd_idx], 0,
  89                sizeof(link->wr_tx_pends[pnd_snd_idx]));
  90         memset(&link->wr_tx_bufs[pnd_snd_idx], 0,
  91                sizeof(link->wr_tx_bufs[pnd_snd_idx]));
  92         if (!test_and_clear_bit(pnd_snd_idx, link->wr_tx_mask))
  93                 return;
  94         if (wc->status) {
  95                 struct smc_link_group *lgr;
  96
  97                 for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
  98                         /* clear full struct smc_wr_tx_pend including .priv */
  99                         memset(&link->wr_tx_pends[i], 0,
 100                                sizeof(link->wr_tx_pends[i]));
 101                         memset(&link->wr_tx_bufs[i], 0,
 102                                sizeof(link->wr_tx_bufs[i]));
 103                         clear_bit(i, link->wr_tx_mask);
 104                 }
 105                 /* terminate connections of this link group abnormally */
 106                 lgr = container_of(link, struct smc_link_group,
 107                                    lnk[SMC_SINGLE_LINK]);
 108                 smc_lgr_terminate(lgr);
 109         }
 110         if (pnd_snd.handler)
 111                 pnd_snd.handler(&pnd_snd.priv, link, wc->status);
 112         wake_up(&link->wr_tx_wait);
 113 }
 114
 115 static void smc_wr_tx_tasklet_fn(unsigned long data)
 116 {
 117         struct smc_ib_device *dev = (struct smc_ib_device *)data;
 118         struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
 119         int i = 0, rc;
 120         int polled = 0;
 121
 122 again:
 123         polled++;
 124         do {
 125                 memset(&wc, 0, sizeof(wc));
 126                 rc = ib_poll_cq(dev->roce_cq_send, SMC_WR_MAX_POLL_CQE, wc);
 127                 if (polled == 1) {
 128                         ib_req_notify_cq(dev->roce_cq_send,
 129                                          IB_CQ_NEXT_COMP |
 130                                          IB_CQ_REPORT_MISSED_EVENTS);
 131                 }
 132                 if (!rc)
 133                         break;
 134                 for (i = 0; i < rc; i++)
 135                         smc_wr_tx_process_cqe(&wc[i]);
 136         } while (rc > 0);
 137         if (polled == 1)
 138                 goto again;
 139 }
 140
 141 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 142 {
 143         struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
 144
 145         tasklet_schedule(&dev->send_tasklet);
 146 }
 147
 148 /*---------------------------- request submission ---------------------------*/
 149
 150 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
 151 {
 152         *idx = link->wr_tx_cnt;
 153         for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
 154                 if (!test_and_set_bit(*idx, link->wr_tx_mask))
 155                         return 0;
 156         }
 157         *idx = link->wr_tx_cnt;
 158         return -EBUSY;
 159 }
 160
 161 /**
 162  * smc_wr_tx_get_free_slot() - returns buffer for message assembly,
 163  *                      and sets info for pending transmit tracking
 164  * @link:               Pointer to smc_link used to later send the message.
 165  * @handler:            Send completion handler function pointer.
 166  * @wr_buf:             Out value returns pointer to message buffer.
 167  * @wr_pend_priv:       Out value returns pointer serving as handler context.
 168  *
 169  * Return: 0 on success, or -errno on error.
 170  */
 171 int smc_wr_tx_get_free_slot(struct smc_link *link,
 172                             smc_wr_tx_handler handler,
 173                             struct smc_wr_buf **wr_buf,
 174                             struct smc_wr_tx_pend_priv **wr_pend_priv)
 175 {
 176         struct smc_wr_tx_pend *wr_pend;
 177         u32 idx = link->wr_tx_cnt;
 178         struct ib_send_wr *wr_ib;
 179         u64 wr_id;
 180         int rc;
 181
 182         *wr_buf = NULL;
 183         *wr_pend_priv = NULL;
 184         if (in_softirq()) {
 185                 rc = smc_wr_tx_get_free_slot_index(link, &idx);
 186                 if (rc)
 187                         return rc;
 188         } else {
 189                 struct smc_link_group *lgr;
 190
 191                 lgr = container_of(link, struct smc_link_group,
 192                                    lnk[SMC_SINGLE_LINK]);
 193                 rc = wait_event_timeout(
 194                         link->wr_tx_wait,
 195                         list_empty(&lgr->list) || /* lgr terminated */
 196                         (smc_wr_tx_get_free_slot_index(link, &idx) != -EBUSY),
 197                         SMC_WR_TX_WAIT_FREE_SLOT_TIME);
 198                 if (!rc) {
 199                         /* timeout - terminate connections */
 200                         smc_lgr_terminate(lgr);
 201                         return -EPIPE;
 202                 }
 203                 if (idx == link->wr_tx_cnt)
 204                         return -EPIPE;
 205         }
 206         wr_id = smc_wr_tx_get_next_wr_id(link);
 207         wr_pend = &link->wr_tx_pends[idx];
 208         wr_pend->wr_id = wr_id;
 209         wr_pend->handler = handler;
 210         wr_pend->link = link;
 211         wr_pend->idx = idx;
 212         wr_ib = &link->wr_tx_ibs[idx];
 213         wr_ib->wr_id = wr_id;
 214         *wr_buf = &link->wr_tx_bufs[idx];
 215         *wr_pend_priv = &wr_pend->priv;
 216         return 0;
 217 }
 218
 219 int smc_wr_tx_put_slot(struct smc_link *link,
 220                        struct smc_wr_tx_pend_priv *wr_pend_priv)
 221 {
 222         struct smc_wr_tx_pend *pend;
 223
 224         pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv);
 225         if (pend->idx < link->wr_tx_cnt) {
 226                 /* clear the full struct smc_wr_tx_pend including .priv */
 227                 memset(&link->wr_tx_pends[pend->idx], 0,
 228                        sizeof(link->wr_tx_pends[pend->idx]));
 229                 memset(&link->wr_tx_bufs[pend->idx], 0,
 230                        sizeof(link->wr_tx_bufs[pend->idx]));
 231                 test_and_clear_bit(pend->idx, link->wr_tx_mask);
 232                 return 1;
 233         }
 234
 235         return 0;
 236 }
 237
 238 /* Send prepared WR slot via ib_post_send.
 239  * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
 240  */
 241 int smc_wr_tx_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv)
 242 {
 243         struct ib_send_wr *failed_wr = NULL;
 244         struct smc_wr_tx_pend *pend;
 245         int rc;
 246
 247         ib_req_notify_cq(link->smcibdev->roce_cq_send,
 248                          IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
 249         pend = container_of(priv, struct smc_wr_tx_pend, priv);
 250         rc = ib_post_send(link->roce_qp, &link->wr_tx_ibs[pend->idx],
 251                           &failed_wr);
 252         if (rc) {
 253                 struct smc_link_group *lgr =
 254                         container_of(link, struct smc_link_group,
 255                                      lnk[SMC_SINGLE_LINK]);
 256
 257                 smc_wr_tx_put_slot(link, priv);
 258                 smc_lgr_terminate(lgr);
 259         }
 260         return rc;
 261 }
 262
 263 /* Register a memory region and wait for result. */
 264 int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
 265 {
 266         struct ib_send_wr *failed_wr = NULL;
 267         int rc;
 268
 269         ib_req_notify_cq(link->smcibdev->roce_cq_send,
 270                          IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
 271         link->wr_reg_state = POSTED;
 272         link->wr_reg.wr.wr_id = (u64)(uintptr_t)mr;
 273         link->wr_reg.mr = mr;
 274         link->wr_reg.key = mr->rkey;
 275         failed_wr = &link->wr_reg.wr;
 276         rc = ib_post_send(link->roce_qp, &link->wr_reg.wr, &failed_wr);
 277         WARN_ON(failed_wr != &link->wr_reg.wr);
 278         if (rc)
 279                 return rc;
 280
 281         rc = wait_event_interruptible_timeout(link->wr_reg_wait,
 282                                               (link->wr_reg_state != POSTED),
 283                                               SMC_WR_REG_MR_WAIT_TIME);
 284         if (!rc) {
 285                 /* timeout - terminate connections */
 286                 struct smc_link_group *lgr;
 287
 288                 lgr = container_of(link, struct smc_link_group,
 289                                    lnk[SMC_SINGLE_LINK]);
 290                 smc_lgr_terminate(lgr);
 291                 return -EPIPE;
 292         }
 293         if (rc == -ERESTARTSYS)
 294                 return -EINTR;
 295         switch (link->wr_reg_state) {
 296         case CONFIRMED:
 297                 rc = 0;
 298                 break;
 299         case FAILED:
 300                 rc = -EIO;
 301                 break;
 302         case POSTED:
 303                 rc = -EPIPE;
 304                 break;
 305         }
 306         return rc;
 307 }
 308
 309 void smc_wr_tx_dismiss_slots(struct smc_link *link, u8 wr_tx_hdr_type,
 310                              smc_wr_tx_filter filter,
 311                              smc_wr_tx_dismisser dismisser,
 312                              unsigned long data)
 313 {
 314         struct smc_wr_tx_pend_priv *tx_pend;
 315         struct smc_wr_rx_hdr *wr_tx;
 316         int i;
 317
 318         for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
 319                 wr_tx = (struct smc_wr_rx_hdr *)&link->wr_tx_bufs[i];
 320                 if (wr_tx->type != wr_tx_hdr_type)
 321                         continue;
 322                 tx_pend = &link->wr_tx_pends[i].priv;
 323                 if (filter(tx_pend, data))
 324                         dismisser(tx_pend);
 325         }
 326 }
 327
 328 /****************************** receive queue ********************************/
 329
 330 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler)
 331 {
 332         struct smc_wr_rx_handler *h_iter;
 333         int rc = 0;
 334
 335         spin_lock(&smc_wr_rx_hash_lock);
 336         hash_for_each_possible(smc_wr_rx_hash, h_iter, list, handler->type) {
 337                 if (h_iter->type == handler->type) {
 338                         rc = -EEXIST;
 339                         goto out_unlock;
 340                 }
 341         }
 342         hash_add(smc_wr_rx_hash, &handler->list, handler->type);
 343 out_unlock:
 344         spin_unlock(&smc_wr_rx_hash_lock);
 345         return rc;
 346 }
 347
 348 /* Demultiplex a received work request based on the message type to its handler.
 349  * Relies on smc_wr_rx_hash having been completely filled before any IB WRs,
 350  * and not being modified any more afterwards so we don't need to lock it.
 351  */
 352 static inline void smc_wr_rx_demultiplex(struct ib_wc *wc)
 353 {
 354         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
 355         struct smc_wr_rx_handler *handler;
 356         struct smc_wr_rx_hdr *wr_rx;
 357         u64 temp_wr_id;
 358         u32 index;
 359
 360         if (wc->byte_len < sizeof(*wr_rx))
 361                 return; /* short message */
 362         temp_wr_id = wc->wr_id;
 363         index = do_div(temp_wr_id, link->wr_rx_cnt);
 364         wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[index];
 365         hash_for_each_possible(smc_wr_rx_hash, handler, list, wr_rx->type) {
 366                 if (handler->type == wr_rx->type)
 367                         handler->handler(wc, wr_rx);
 368         }
 369 }
 370
 371 static inline void smc_wr_rx_process_cqes(struct ib_wc wc[], int num)
 372 {
 373         struct smc_link *link;
 374         int i;
 375
 376         for (i = 0; i < num; i++) {
 377                 link = wc[i].qp->qp_context;
 378                 if (wc[i].status == IB_WC_SUCCESS) {
 379                         link->wr_rx_tstamp = jiffies;
 380                         smc_wr_rx_demultiplex(&wc[i]);
 381                         smc_wr_rx_post(link); /* refill WR RX */
 382                 } else {
 383                         struct smc_link_group *lgr;
 384
 385                         /* handle status errors */
 386                         switch (wc[i].status) {
 387                         case IB_WC_RETRY_EXC_ERR:
 388                         case IB_WC_RNR_RETRY_EXC_ERR:
 389                         case IB_WC_WR_FLUSH_ERR:
 390                                 /* terminate connections of this link group
 391                                  * abnormally
 392                                  */
 393                                 lgr = container_of(link, struct smc_link_group,
 394                                                    lnk[SMC_SINGLE_LINK]);
 395                                 smc_lgr_terminate(lgr);
 396                                 break;
 397                         default:
 398                                 smc_wr_rx_post(link); /* refill WR RX */
 399                                 break;
 400                         }
 401                 }
 402         }
 403 }
 404
 405 static void smc_wr_rx_tasklet_fn(unsigned long data)
 406 {
 407         struct smc_ib_device *dev = (struct smc_ib_device *)data;
 408         struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
 409         int polled = 0;
 410         int rc;
 411
 412 again:
 413         polled++;
 414         do {
 415                 memset(&wc, 0, sizeof(wc));
 416                 rc = ib_poll_cq(dev->roce_cq_recv, SMC_WR_MAX_POLL_CQE, wc);
 417                 if (polled == 1) {
 418                         ib_req_notify_cq(dev->roce_cq_recv,
 419                                          IB_CQ_SOLICITED_MASK
 420                                          | IB_CQ_REPORT_MISSED_EVENTS);
 421                 }
 422                 if (!rc)
 423                         break;
 424                 smc_wr_rx_process_cqes(&wc[0], rc);
 425         } while (rc > 0);
 426         if (polled == 1)
 427                 goto again;
 428 }
 429
 430 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 431 {
 432         struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
 433
 434         tasklet_schedule(&dev->recv_tasklet);
 435 }
 436
 437 int smc_wr_rx_post_init(struct smc_link *link)
 438 {
 439         u32 i;
 440         int rc = 0;
 441
 442         for (i = 0; i < link->wr_rx_cnt; i++)
 443                 rc = smc_wr_rx_post(link);
 444         return rc;
 445 }
 446
 447 /***************************** init, exit, misc ******************************/
 448
 449 void smc_wr_remember_qp_attr(struct smc_link *lnk)
 450 {
 451         struct ib_qp_attr *attr = &lnk->qp_attr;
 452         struct ib_qp_init_attr init_attr;
 453
 454         memset(attr, 0, sizeof(*attr));
 455         memset(&init_attr, 0, sizeof(init_attr));
 456         ib_query_qp(lnk->roce_qp, attr,
 457                     IB_QP_STATE |
 458                     IB_QP_CUR_STATE |
 459                     IB_QP_PKEY_INDEX |
 460                     IB_QP_PORT |
 461                     IB_QP_QKEY |
 462                     IB_QP_AV |
 463                     IB_QP_PATH_MTU |
 464                     IB_QP_TIMEOUT |
 465                     IB_QP_RETRY_CNT |
 466                     IB_QP_RNR_RETRY |
 467                     IB_QP_RQ_PSN |
 468                     IB_QP_ALT_PATH |
 469                     IB_QP_MIN_RNR_TIMER |
 470                     IB_QP_SQ_PSN |
 471                     IB_QP_PATH_MIG_STATE |
 472                     IB_QP_CAP |
 473                     IB_QP_DEST_QPN,
 474                     &init_attr);
 475
 476         lnk->wr_tx_cnt = min_t(size_t, SMC_WR_BUF_CNT,
 477                                lnk->qp_attr.cap.max_send_wr);
 478         lnk->wr_rx_cnt = min_t(size_t, SMC_WR_BUF_CNT * 3,
 479                                lnk->qp_attr.cap.max_recv_wr);
 480 }
 481
 482 static void smc_wr_init_sge(struct smc_link *lnk)
 483 {
 484         u32 i;
 485
 486         for (i = 0; i < lnk->wr_tx_cnt; i++) {
 487                 lnk->wr_tx_sges[i].addr =
 488                         lnk->wr_tx_dma_addr + i * SMC_WR_BUF_SIZE;
 489                 lnk->wr_tx_sges[i].length = SMC_WR_TX_SIZE;
 490                 lnk->wr_tx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
 491                 lnk->wr_tx_ibs[i].next = NULL;
 492                 lnk->wr_tx_ibs[i].sg_list = &lnk->wr_tx_sges[i];
 493                 lnk->wr_tx_ibs[i].num_sge = 1;
 494                 lnk->wr_tx_ibs[i].opcode = IB_WR_SEND;
 495                 lnk->wr_tx_ibs[i].send_flags =
 496                         IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 497         }
 498         for (i = 0; i < lnk->wr_rx_cnt; i++) {
 499                 lnk->wr_rx_sges[i].addr =
 500                         lnk->wr_rx_dma_addr + i * SMC_WR_BUF_SIZE;
 501                 lnk->wr_rx_sges[i].length = SMC_WR_BUF_SIZE;
 502                 lnk->wr_rx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
 503                 lnk->wr_rx_ibs[i].next = NULL;
 504                 lnk->wr_rx_ibs[i].sg_list = &lnk->wr_rx_sges[i];
 505                 lnk->wr_rx_ibs[i].num_sge = 1;
 506         }
 507         lnk->wr_reg.wr.next = NULL;
 508         lnk->wr_reg.wr.num_sge = 0;
 509         lnk->wr_reg.wr.send_flags = IB_SEND_SIGNALED;
 510         lnk->wr_reg.wr.opcode = IB_WR_REG_MR;
 511         lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE;
 512 }
 513
 514 void smc_wr_free_link(struct smc_link *lnk)
 515 {
 516         struct ib_device *ibdev;
 517
 518         memset(lnk->wr_tx_mask, 0,
 519                BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
 520
 521         if (!lnk->smcibdev)
 522                 return;
 523         ibdev = lnk->smcibdev->ibdev;
 524
 525         if (lnk->wr_rx_dma_addr) {
 526                 ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
 527                                     SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
 528                                     DMA_FROM_DEVICE);
 529                 lnk->wr_rx_dma_addr = 0;
 530         }
 531         if (lnk->wr_tx_dma_addr) {
 532                 ib_dma_unmap_single(ibdev, lnk->wr_tx_dma_addr,
 533                                     SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
 534                                     DMA_TO_DEVICE);
 535                 lnk->wr_tx_dma_addr = 0;
 536         }
 537 }
 538
 539 void smc_wr_free_link_mem(struct smc_link *lnk)
 540 {
 541         kfree(lnk->wr_tx_pends);
 542         lnk->wr_tx_pends = NULL;
 543         kfree(lnk->wr_tx_mask);
 544         lnk->wr_tx_mask = NULL;
 545         kfree(lnk->wr_tx_sges);
 546         lnk->wr_tx_sges = NULL;
 547         kfree(lnk->wr_rx_sges);
 548         lnk->wr_rx_sges = NULL;
 549         kfree(lnk->wr_rx_ibs);
 550         lnk->wr_rx_ibs = NULL;
 551         kfree(lnk->wr_tx_ibs);
 552         lnk->wr_tx_ibs = NULL;
 553         kfree(lnk->wr_tx_bufs);
 554         lnk->wr_tx_bufs = NULL;
 555         kfree(lnk->wr_rx_bufs);
 556         lnk->wr_rx_bufs = NULL;
 557 }
 558
 559 int smc_wr_alloc_link_mem(struct smc_link *link)
 560 {
 561         /* allocate link related memory */
 562         link->wr_tx_bufs = kcalloc(SMC_WR_BUF_CNT, SMC_WR_BUF_SIZE, GFP_KERNEL);
 563         if (!link->wr_tx_bufs)
 564                 goto no_mem;
 565         link->wr_rx_bufs = kcalloc(SMC_WR_BUF_CNT * 3, SMC_WR_BUF_SIZE,
 566                                    GFP_KERNEL);
 567         if (!link->wr_rx_bufs)
 568                 goto no_mem_wr_tx_bufs;
 569         link->wr_tx_ibs = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_ibs[0]),
 570                                   GFP_KERNEL);
 571         if (!link->wr_tx_ibs)
 572                 goto no_mem_wr_rx_bufs;
 573         link->wr_rx_ibs = kcalloc(SMC_WR_BUF_CNT * 3,
 574                                   sizeof(link->wr_rx_ibs[0]),
 575                                   GFP_KERNEL);
 576         if (!link->wr_rx_ibs)
 577                 goto no_mem_wr_tx_ibs;
 578         link->wr_tx_sges = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_sges[0]),
 579                                    GFP_KERNEL);
 580         if (!link->wr_tx_sges)
 581                 goto no_mem_wr_rx_ibs;
 582         link->wr_rx_sges = kcalloc(SMC_WR_BUF_CNT * 3,
 583                                    sizeof(link->wr_rx_sges[0]),
 584                                    GFP_KERNEL);
 585         if (!link->wr_rx_sges)
 586                 goto no_mem_wr_tx_sges;
 587         link->wr_tx_mask = kcalloc(BITS_TO_LONGS(SMC_WR_BUF_CNT),
 588                                    sizeof(*link->wr_tx_mask),
 589                                    GFP_KERNEL);
 590         if (!link->wr_tx_mask)
 591                 goto no_mem_wr_rx_sges;
 592         link->wr_tx_pends = kcalloc(SMC_WR_BUF_CNT,
 593                                     sizeof(link->wr_tx_pends[0]),
 594                                     GFP_KERNEL);
 595         if (!link->wr_tx_pends)
 596                 goto no_mem_wr_tx_mask;
 597         return 0;
 598
 599 no_mem_wr_tx_mask:
 600         kfree(link->wr_tx_mask);
 601 no_mem_wr_rx_sges:
 602         kfree(link->wr_rx_sges);
 603 no_mem_wr_tx_sges:
 604         kfree(link->wr_tx_sges);
 605 no_mem_wr_rx_ibs:
 606         kfree(link->wr_rx_ibs);
 607 no_mem_wr_tx_ibs:
 608         kfree(link->wr_tx_ibs);
 609 no_mem_wr_rx_bufs:
 610         kfree(link->wr_rx_bufs);
 611 no_mem_wr_tx_bufs:
 612         kfree(link->wr_tx_bufs);
 613 no_mem:
 614         return -ENOMEM;
 615 }
 616
 617 void smc_wr_remove_dev(struct smc_ib_device *smcibdev)
 618 {
 619         tasklet_kill(&smcibdev->recv_tasklet);
 620         tasklet_kill(&smcibdev->send_tasklet);
 621 }
 622
 623 void smc_wr_add_dev(struct smc_ib_device *smcibdev)
 624 {
 625         tasklet_init(&smcibdev->recv_tasklet, smc_wr_rx_tasklet_fn,
 626                      (unsigned long)smcibdev);
 627         tasklet_init(&smcibdev->send_tasklet, smc_wr_tx_tasklet_fn,
 628                      (unsigned long)smcibdev);
 629 }
 630
 631 int smc_wr_create_link(struct smc_link *lnk)
 632 {
 633         struct ib_device *ibdev = lnk->smcibdev->ibdev;
 634         int rc = 0;
 635
 636         smc_wr_tx_set_wr_id(&lnk->wr_tx_id, 0);
 637         lnk->wr_rx_id = 0;
 638         lnk->wr_rx_dma_addr = ib_dma_map_single(
 639                 ibdev, lnk->wr_rx_bufs, SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
 640                 DMA_FROM_DEVICE);
 641         if (ib_dma_mapping_error(ibdev, lnk->wr_rx_dma_addr)) {
 642                 lnk->wr_rx_dma_addr = 0;
 643                 rc = -EIO;
 644                 goto out;
 645         }
 646         lnk->wr_tx_dma_addr = ib_dma_map_single(
 647                 ibdev, lnk->wr_tx_bufs, SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
 648                 DMA_TO_DEVICE);
 649         if (ib_dma_mapping_error(ibdev, lnk->wr_tx_dma_addr)) {
 650                 rc = -EIO;
 651                 goto dma_unmap;
 652         }
 653         smc_wr_init_sge(lnk);
 654         memset(lnk->wr_tx_mask, 0,
 655                BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
 656         init_waitqueue_head(&lnk->wr_tx_wait);
 657         init_waitqueue_head(&lnk->wr_reg_wait);
 658         return rc;
 659
 660 dma_unmap:
 661         ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
 662                             SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
 663                             DMA_FROM_DEVICE);
 664         lnk->wr_rx_dma_addr = 0;
 665 out:
 666         return rc;
 667 }