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