net/smc/smc_wr.c

   1 /*
   2  * Shared Memory Communications over RDMA (SMC-R) and RoCE
   3  *
   4  * Work Requests exploiting Infiniband API
   5  *
   6  * Work requests (WR) of type ib_post_send or ib_post_recv respectively
   7  * are submitted to either RC SQ or RC RQ respectively
   8  * (reliably connected send/receive queue)
   9  * and become work queue entries (WQEs).
  10  * While an SQ WR/WQE is pending, we track it until transmission completion.
  11  * Through a send or receive completion queue (CQ) respectively,
  12  * we get completion queue entries (CQEs) [aka work completions (WCs)].
  13  * Since the CQ callback is called from IRQ context, we split work by using
  14  * bottom halves implemented by tasklets.
  15  *
  16  * SMC uses this to exchange LLC (link layer control)
  17  * and CDC (connection data control) messages.
  18  *
  19  * Copyright IBM Corp. 2016
  20  *
  21  * Author(s):  Steffen Maier <[email protected]>
  22  */
  23
  24 #include <linux/atomic.h>
  25 #include <linux/hashtable.h>
  26 #include <linux/wait.h>
  27 #include <rdma/ib_verbs.h>
  28 #include <asm/div64.h>
  29
  30 #include "smc.h"
  31 #include "smc_wr.h"
  32
  33 #define SMC_WR_MAX_POLL_CQE 10  /* max. # of compl. queue elements in 1 poll */
  34
  35 #define SMC_WR_RX_HASH_BITS 4
  36 static DEFINE_HASHTABLE(smc_wr_rx_hash, SMC_WR_RX_HASH_BITS);
  37 static DEFINE_SPINLOCK(smc_wr_rx_hash_lock);
  38
  39 struct smc_wr_tx_pend { /* control data for a pending send request */
  40         u64                     wr_id;          /* work request id sent */
  41         smc_wr_tx_handler       handler;
  42         enum ib_wc_status       wc_status;      /* CQE status */
  43         struct smc_link         *link;
  44         u32                     idx;
  45         struct smc_wr_tx_pend_priv priv;
  46 };
  47
  48 /******************************** send queue *********************************/
  49
  50 /*------------------------------- completion --------------------------------*/
  51
  52 static inline int smc_wr_tx_find_pending_index(struct smc_link *link, u64 wr_id)
  53 {
  54         u32 i;
  55
  56         for (i = 0; i < link->wr_tx_cnt; i++) {
  57                 if (link->wr_tx_pends[i].wr_id == wr_id)
  58                         return i;
  59         }
  60         return link->wr_tx_cnt;
  61 }
  62
  63 static inline void smc_wr_tx_process_cqe(struct ib_wc *wc)
  64 {
  65         struct smc_wr_tx_pend pnd_snd;
  66         struct smc_link *link;
  67         u32 pnd_snd_idx;
  68         int i;
  69
  70         link = wc->qp->qp_context;
  71
  72         if (wc->opcode == IB_WC_REG_MR) {
  73                 if (wc->status)
  74                         link->wr_reg_state = FAILED;
  75                 else
  76                         link->wr_reg_state = CONFIRMED;
  77                 wake_up(&link->wr_reg_wait);
  78                 return;
  79         }
  80
  81         pnd_snd_idx = smc_wr_tx_find_pending_index(link, wc->wr_id);
  82         if (pnd_snd_idx == link->wr_tx_cnt)
  83                 return;
  84         link->wr_tx_pends[pnd_snd_idx].wc_status = wc->status;
  85         memcpy(&pnd_snd, &link->wr_tx_pends[pnd_snd_idx], sizeof(pnd_snd));
  86         /* clear the full struct smc_wr_tx_pend including .priv */
  87         memset(&link->wr_tx_pends[pnd_snd_idx], 0,
  88                sizeof(link->wr_tx_pends[pnd_snd_idx]));
  89         memset(&link->wr_tx_bufs[pnd_snd_idx], 0,
  90                sizeof(link->wr_tx_bufs[pnd_snd_idx]));
  91         if (!test_and_clear_bit(pnd_snd_idx, link->wr_tx_mask))
  92                 return;
  93         if (wc->status) {
  94                 struct smc_link_group *lgr;
  95
  96                 for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
  97                         /* clear full struct smc_wr_tx_pend including .priv */
  98                         memset(&link->wr_tx_pends[i], 0,
  99                                sizeof(link->wr_tx_pends[i]));
 100                         memset(&link->wr_tx_bufs[i], 0,
 101                                sizeof(link->wr_tx_bufs[i]));
 102                         clear_bit(i, link->wr_tx_mask);
 103                 }
 104                 /* terminate connections of this link group abnormally */
 105                 lgr = container_of(link, struct smc_link_group,
 106                                    lnk[SMC_SINGLE_LINK]);
 107                 smc_lgr_terminate(lgr);
 108         }
 109         if (pnd_snd.handler)
 110                 pnd_snd.handler(&pnd_snd.priv, link, wc->status);
 111         wake_up(&link->wr_tx_wait);
 112 }
 113
 114 static void smc_wr_tx_tasklet_fn(unsigned long data)
 115 {
 116         struct smc_ib_device *dev = (struct smc_ib_device *)data;
 117         struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
 118         int i = 0, rc;
 119         int polled = 0;
 120
 121 again:
 122         polled++;
 123         do {
 124                 rc = ib_poll_cq(dev->roce_cq_send, SMC_WR_MAX_POLL_CQE, wc);
 125                 if (polled == 1) {
 126                         ib_req_notify_cq(dev->roce_cq_send,
 127                                          IB_CQ_NEXT_COMP |
 128                                          IB_CQ_REPORT_MISSED_EVENTS);
 129                 }
 130                 if (!rc)
 131                         break;
 132                 for (i = 0; i < rc; i++)
 133                         smc_wr_tx_process_cqe(&wc[i]);
 134         } while (rc > 0);
 135         if (polled == 1)
 136                 goto again;
 137 }
 138
 139 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 140 {
 141         struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
 142
 143         tasklet_schedule(&dev->send_tasklet);
 144 }
 145
 146 /*---------------------------- request submission ---------------------------*/
 147
 148 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
 149 {
 150         *idx = link->wr_tx_cnt;
 151         for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
 152                 if (!test_and_set_bit(*idx, link->wr_tx_mask))
 153                         return 0;
 154         }
 155         *idx = link->wr_tx_cnt;
 156         return -EBUSY;
 157 }
 158
 159 /**
 160  * smc_wr_tx_get_free_slot() - returns buffer for message assembly,
 161  *                      and sets info for pending transmit tracking
 162  * @link:               Pointer to smc_link used to later send the message.
 163  * @handler:            Send completion handler function pointer.
 164  * @wr_buf:             Out value returns pointer to message buffer.
 165  * @wr_pend_priv:       Out value returns pointer serving as handler context.
 166  *
 167  * Return: 0 on success, or -errno on error.
 168  */
 169 int smc_wr_tx_get_free_slot(struct smc_link *link,
 170                             smc_wr_tx_handler handler,
 171                             struct smc_wr_buf **wr_buf,
 172                             struct smc_wr_tx_pend_priv **wr_pend_priv)
 173 {
 174         struct smc_wr_tx_pend *wr_pend;
 175         struct ib_send_wr *wr_ib;
 176         u64 wr_id;
 177         u32 idx;
 178         int rc;
 179
 180         *wr_buf = NULL;
 181         *wr_pend_priv = NULL;
 182         if (in_softirq()) {
 183                 rc = smc_wr_tx_get_free_slot_index(link, &idx);
 184                 if (rc)
 185                         return rc;
 186         } else {
 187                 rc = wait_event_interruptible_timeout(
 188                         link->wr_tx_wait,
 189                         (smc_wr_tx_get_free_slot_index(link, &idx) != -EBUSY),
 190                         SMC_WR_TX_WAIT_FREE_SLOT_TIME);
 191                 if (!rc) {
 192                         /* timeout - terminate connections */
 193                         struct smc_link_group *lgr;
 194
 195                         lgr = container_of(link, struct smc_link_group,
 196                                            lnk[SMC_SINGLE_LINK]);
 197                         smc_lgr_terminate(lgr);
 198                         return -EPIPE;
 199                 }
 200                 if (rc == -ERESTARTSYS)
 201                         return -EINTR;
 202                 if (idx == link->wr_tx_cnt)
 203                         return -EPIPE;
 204         }
 205         wr_id = smc_wr_tx_get_next_wr_id(link);
 206         wr_pend = &link->wr_tx_pends[idx];
 207         wr_pend->wr_id = wr_id;
 208         wr_pend->handler = handler;
 209         wr_pend->link = link;
 210         wr_pend->idx = idx;
 211         wr_ib = &link->wr_tx_ibs[idx];
 212         wr_ib->wr_id = wr_id;
 213         *wr_buf = &link->wr_tx_bufs[idx];
 214         *wr_pend_priv = &wr_pend->priv;
 215         return 0;
 216 }
 217
 218 int smc_wr_tx_put_slot(struct smc_link *link,
 219                        struct smc_wr_tx_pend_priv *wr_pend_priv)
 220 {
 221         struct smc_wr_tx_pend *pend;
 222
 223         pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv);
 224         if (pend->idx < link->wr_tx_cnt) {
 225                 /* clear the full struct smc_wr_tx_pend including .priv */
 226                 memset(&link->wr_tx_pends[pend->idx], 0,
 227                        sizeof(link->wr_tx_pends[pend->idx]));
 228                 memset(&link->wr_tx_bufs[pend->idx], 0,
 229                        sizeof(link->wr_tx_bufs[pend->idx]));
 230                 test_and_clear_bit(pend->idx, link->wr_tx_mask);
 231                 return 1;
 232         }
 233
 234         return 0;
 235 }
 236
 237 /* Send prepared WR slot via ib_post_send.
 238  * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
 239  */
 240 int smc_wr_tx_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv)
 241 {
 242         struct ib_send_wr *failed_wr = NULL;
 243         struct smc_wr_tx_pend *pend;
 244         int rc;
 245
 246         ib_req_notify_cq(link->smcibdev->roce_cq_send,
 247                          IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
 248         pend = container_of(priv, struct smc_wr_tx_pend, priv);
 249         rc = ib_post_send(link->roce_qp, &link->wr_tx_ibs[pend->idx],
 250                           &failed_wr);
 251         if (rc)
 252                 smc_wr_tx_put_slot(link, priv);
 253         return rc;
 254 }
 255
 256 /* Register a memory region and wait for result. */
 257 int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
 258 {
 259         struct ib_send_wr *failed_wr = NULL;
 260         int rc;
 261
 262         ib_req_notify_cq(link->smcibdev->roce_cq_send,
 263                          IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
 264         link->wr_reg_state = POSTED;
 265         link->wr_reg.wr.wr_id = (u64)(uintptr_t)mr;
 266         link->wr_reg.mr = mr;
 267         link->wr_reg.key = mr->rkey;
 268         failed_wr = &link->wr_reg.wr;
 269         rc = ib_post_send(link->roce_qp, &link->wr_reg.wr, &failed_wr);
 270         WARN_ON(failed_wr != &link->wr_reg.wr);
 271         if (rc)
 272                 return rc;
 273
 274         rc = wait_event_interruptible_timeout(link->wr_reg_wait,
 275                                               (link->wr_reg_state != POSTED),
 276                                               SMC_WR_REG_MR_WAIT_TIME);
 277         if (!rc) {
 278                 /* timeout - terminate connections */
 279                 struct smc_link_group *lgr;
 280
 281                 lgr = container_of(link, struct smc_link_group,
 282                                    lnk[SMC_SINGLE_LINK]);
 283                 smc_lgr_terminate(lgr);
 284                 return -EPIPE;
 285         }
 286         if (rc == -ERESTARTSYS)
 287                 return -EINTR;
 288         switch (link->wr_reg_state) {
 289         case CONFIRMED:
 290                 rc = 0;
 291                 break;
 292         case FAILED:
 293                 rc = -EIO;
 294                 break;
 295         case POSTED:
 296                 rc = -EPIPE;
 297                 break;
 298         }
 299         return rc;
 300 }
 301
 302 void smc_wr_tx_dismiss_slots(struct smc_link *link, u8 wr_rx_hdr_type,
 303                              smc_wr_tx_filter filter,
 304                              smc_wr_tx_dismisser dismisser,
 305                              unsigned long data)
 306 {
 307         struct smc_wr_tx_pend_priv *tx_pend;
 308         struct smc_wr_rx_hdr *wr_rx;
 309         int i;
 310
 311         for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
 312                 wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[i];
 313                 if (wr_rx->type != wr_rx_hdr_type)
 314                         continue;
 315                 tx_pend = &link->wr_tx_pends[i].priv;
 316                 if (filter(tx_pend, data))
 317                         dismisser(tx_pend);
 318         }
 319 }
 320
 321 bool smc_wr_tx_has_pending(struct smc_link *link, u8 wr_rx_hdr_type,
 322                            smc_wr_tx_filter filter, unsigned long data)
 323 {
 324         struct smc_wr_tx_pend_priv *tx_pend;
 325         struct smc_wr_rx_hdr *wr_rx;
 326         int i;
 327
 328         for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
 329                 wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[i];
 330                 if (wr_rx->type != wr_rx_hdr_type)
 331                         continue;
 332                 tx_pend = &link->wr_tx_pends[i].priv;
 333                 if (filter(tx_pend, data))
 334                         return true;
 335         }
 336         return false;
 337 }
 338
 339 /****************************** receive queue ********************************/
 340
 341 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler)
 342 {
 343         struct smc_wr_rx_handler *h_iter;
 344         int rc = 0;
 345
 346         spin_lock(&smc_wr_rx_hash_lock);
 347         hash_for_each_possible(smc_wr_rx_hash, h_iter, list, handler->type) {
 348                 if (h_iter->type == handler->type) {
 349                         rc = -EEXIST;
 350                         goto out_unlock;
 351                 }
 352         }
 353         hash_add(smc_wr_rx_hash, &handler->list, handler->type);
 354 out_unlock:
 355         spin_unlock(&smc_wr_rx_hash_lock);
 356         return rc;
 357 }
 358
 359 /* Demultiplex a received work request based on the message type to its handler.
 360  * Relies on smc_wr_rx_hash having been completely filled before any IB WRs,
 361  * and not being modified any more afterwards so we don't need to lock it.
 362  */
 363 static inline void smc_wr_rx_demultiplex(struct ib_wc *wc)
 364 {
 365         struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
 366         struct smc_wr_rx_handler *handler;
 367         struct smc_wr_rx_hdr *wr_rx;
 368         u64 temp_wr_id;
 369         u32 index;
 370
 371         if (wc->byte_len < sizeof(*wr_rx))
 372                 return; /* short message */
 373         temp_wr_id = wc->wr_id;
 374         index = do_div(temp_wr_id, link->wr_rx_cnt);
 375         wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[index];
 376         hash_for_each_possible(smc_wr_rx_hash, handler, list, wr_rx->type) {
 377                 if (handler->type == wr_rx->type)
 378                         handler->handler(wc, wr_rx);
 379         }
 380 }
 381
 382 static inline void smc_wr_rx_process_cqes(struct ib_wc wc[], int num)
 383 {
 384         struct smc_link *link;
 385         int i;
 386
 387         for (i = 0; i < num; i++) {
 388                 link = wc[i].qp->qp_context;
 389                 if (wc[i].status == IB_WC_SUCCESS) {
 390                         smc_wr_rx_demultiplex(&wc[i]);
 391                         smc_wr_rx_post(link); /* refill WR RX */
 392                 } else {
 393                         struct smc_link_group *lgr;
 394
 395                         /* handle status errors */
 396                         switch (wc[i].status) {
 397                         case IB_WC_RETRY_EXC_ERR:
 398                         case IB_WC_RNR_RETRY_EXC_ERR:
 399                         case IB_WC_WR_FLUSH_ERR:
 400                                 /* terminate connections of this link group
 401                                  * abnormally
 402                                  */
 403                                 lgr = container_of(link, struct smc_link_group,
 404                                                    lnk[SMC_SINGLE_LINK]);
 405                                 smc_lgr_terminate(lgr);
 406                                 break;
 407                         default:
 408                                 smc_wr_rx_post(link); /* refill WR RX */
 409                                 break;
 410                         }
 411                 }
 412         }
 413 }
 414
 415 static void smc_wr_rx_tasklet_fn(unsigned long data)
 416 {
 417         struct smc_ib_device *dev = (struct smc_ib_device *)data;
 418         struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
 419         int polled = 0;
 420         int rc;
 421
 422 again:
 423         polled++;
 424         do {
 425                 memset(&wc, 0, sizeof(wc));
 426                 rc = ib_poll_cq(dev->roce_cq_recv, SMC_WR_MAX_POLL_CQE, wc);
 427                 if (polled == 1) {
 428                         ib_req_notify_cq(dev->roce_cq_recv,
 429                                          IB_CQ_SOLICITED_MASK
 430                                          | IB_CQ_REPORT_MISSED_EVENTS);
 431                 }
 432                 if (!rc)
 433                         break;
 434                 smc_wr_rx_process_cqes(&wc[0], rc);
 435         } while (rc > 0);
 436         if (polled == 1)
 437                 goto again;
 438 }
 439
 440 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
 441 {
 442         struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
 443
 444         tasklet_schedule(&dev->recv_tasklet);
 445 }
 446
 447 int smc_wr_rx_post_init(struct smc_link *link)
 448 {
 449         u32 i;
 450         int rc = 0;
 451
 452         for (i = 0; i < link->wr_rx_cnt; i++)
 453                 rc = smc_wr_rx_post(link);
 454         return rc;
 455 }
 456
 457 /***************************** init, exit, misc ******************************/
 458
 459 void smc_wr_remember_qp_attr(struct smc_link *lnk)
 460 {
 461         struct ib_qp_attr *attr = &lnk->qp_attr;
 462         struct ib_qp_init_attr init_attr;
 463
 464         memset(attr, 0, sizeof(*attr));
 465         memset(&init_attr, 0, sizeof(init_attr));
 466         ib_query_qp(lnk->roce_qp, attr,
 467                     IB_QP_STATE |
 468                     IB_QP_CUR_STATE |
 469                     IB_QP_PKEY_INDEX |
 470                     IB_QP_PORT |
 471                     IB_QP_QKEY |
 472                     IB_QP_AV |
 473                     IB_QP_PATH_MTU |
 474                     IB_QP_TIMEOUT |
 475                     IB_QP_RETRY_CNT |
 476                     IB_QP_RNR_RETRY |
 477                     IB_QP_RQ_PSN |
 478                     IB_QP_ALT_PATH |
 479                     IB_QP_MIN_RNR_TIMER |
 480                     IB_QP_SQ_PSN |
 481                     IB_QP_PATH_MIG_STATE |
 482                     IB_QP_CAP |
 483                     IB_QP_DEST_QPN,
 484                     &init_attr);
 485
 486         lnk->wr_tx_cnt = min_t(size_t, SMC_WR_BUF_CNT,
 487                                lnk->qp_attr.cap.max_send_wr);
 488         lnk->wr_rx_cnt = min_t(size_t, SMC_WR_BUF_CNT * 3,
 489                                lnk->qp_attr.cap.max_recv_wr);
 490 }
 491
 492 static void smc_wr_init_sge(struct smc_link *lnk)
 493 {
 494         u32 i;
 495
 496         for (i = 0; i < lnk->wr_tx_cnt; i++) {
 497                 lnk->wr_tx_sges[i].addr =
 498                         lnk->wr_tx_dma_addr + i * SMC_WR_BUF_SIZE;
 499                 lnk->wr_tx_sges[i].length = SMC_WR_TX_SIZE;
 500                 lnk->wr_tx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
 501                 lnk->wr_tx_ibs[i].next = NULL;
 502                 lnk->wr_tx_ibs[i].sg_list = &lnk->wr_tx_sges[i];
 503                 lnk->wr_tx_ibs[i].num_sge = 1;
 504                 lnk->wr_tx_ibs[i].opcode = IB_WR_SEND;
 505                 lnk->wr_tx_ibs[i].send_flags =
 506                         IB_SEND_SIGNALED | IB_SEND_SOLICITED;
 507         }
 508         for (i = 0; i < lnk->wr_rx_cnt; i++) {
 509                 lnk->wr_rx_sges[i].addr =
 510                         lnk->wr_rx_dma_addr + i * SMC_WR_BUF_SIZE;
 511                 lnk->wr_rx_sges[i].length = SMC_WR_BUF_SIZE;
 512                 lnk->wr_rx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
 513                 lnk->wr_rx_ibs[i].next = NULL;
 514                 lnk->wr_rx_ibs[i].sg_list = &lnk->wr_rx_sges[i];
 515                 lnk->wr_rx_ibs[i].num_sge = 1;
 516         }
 517         lnk->wr_reg.wr.next = NULL;
 518         lnk->wr_reg.wr.num_sge = 0;
 519         lnk->wr_reg.wr.send_flags = IB_SEND_SIGNALED;
 520         lnk->wr_reg.wr.opcode = IB_WR_REG_MR;
 521         lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE;
 522 }
 523
 524 void smc_wr_free_link(struct smc_link *lnk)
 525 {
 526         struct ib_device *ibdev;
 527
 528         memset(lnk->wr_tx_mask, 0,
 529                BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
 530
 531         if (!lnk->smcibdev)
 532                 return;
 533         ibdev = lnk->smcibdev->ibdev;
 534
 535         if (lnk->wr_rx_dma_addr) {
 536                 ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
 537                                     SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
 538                                     DMA_FROM_DEVICE);
 539                 lnk->wr_rx_dma_addr = 0;
 540         }
 541         if (lnk->wr_tx_dma_addr) {
 542                 ib_dma_unmap_single(ibdev, lnk->wr_tx_dma_addr,
 543                                     SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
 544                                     DMA_TO_DEVICE);
 545                 lnk->wr_tx_dma_addr = 0;
 546         }
 547 }
 548
 549 void smc_wr_free_link_mem(struct smc_link *lnk)
 550 {
 551         kfree(lnk->wr_tx_pends);
 552         lnk->wr_tx_pends = NULL;
 553         kfree(lnk->wr_tx_mask);
 554         lnk->wr_tx_mask = NULL;
 555         kfree(lnk->wr_tx_sges);
 556         lnk->wr_tx_sges = NULL;
 557         kfree(lnk->wr_rx_sges);
 558         lnk->wr_rx_sges = NULL;
 559         kfree(lnk->wr_rx_ibs);
 560         lnk->wr_rx_ibs = NULL;
 561         kfree(lnk->wr_tx_ibs);
 562         lnk->wr_tx_ibs = NULL;
 563         kfree(lnk->wr_tx_bufs);
 564         lnk->wr_tx_bufs = NULL;
 565         kfree(lnk->wr_rx_bufs);
 566         lnk->wr_rx_bufs = NULL;
 567 }
 568
 569 int smc_wr_alloc_link_mem(struct smc_link *link)
 570 {
 571         /* allocate link related memory */
 572         link->wr_tx_bufs = kcalloc(SMC_WR_BUF_CNT, SMC_WR_BUF_SIZE, GFP_KERNEL);
 573         if (!link->wr_tx_bufs)
 574                 goto no_mem;
 575         link->wr_rx_bufs = kcalloc(SMC_WR_BUF_CNT * 3, SMC_WR_BUF_SIZE,
 576                                    GFP_KERNEL);
 577         if (!link->wr_rx_bufs)
 578                 goto no_mem_wr_tx_bufs;
 579         link->wr_tx_ibs = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_ibs[0]),
 580                                   GFP_KERNEL);
 581         if (!link->wr_tx_ibs)
 582                 goto no_mem_wr_rx_bufs;
 583         link->wr_rx_ibs = kcalloc(SMC_WR_BUF_CNT * 3,
 584                                   sizeof(link->wr_rx_ibs[0]),
 585                                   GFP_KERNEL);
 586         if (!link->wr_rx_ibs)
 587                 goto no_mem_wr_tx_ibs;
 588         link->wr_tx_sges = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_sges[0]),
 589                                    GFP_KERNEL);
 590         if (!link->wr_tx_sges)
 591                 goto no_mem_wr_rx_ibs;
 592         link->wr_rx_sges = kcalloc(SMC_WR_BUF_CNT * 3,
 593                                    sizeof(link->wr_rx_sges[0]),
 594                                    GFP_KERNEL);
 595         if (!link->wr_rx_sges)
 596                 goto no_mem_wr_tx_sges;
 597         link->wr_tx_mask = kzalloc(
 598                 BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*link->wr_tx_mask),
 599                 GFP_KERNEL);
 600         if (!link->wr_tx_mask)
 601                 goto no_mem_wr_rx_sges;
 602         link->wr_tx_pends = kcalloc(SMC_WR_BUF_CNT,
 603                                     sizeof(link->wr_tx_pends[0]),
 604                                     GFP_KERNEL);
 605         if (!link->wr_tx_pends)
 606                 goto no_mem_wr_tx_mask;
 607         return 0;
 608
 609 no_mem_wr_tx_mask:
 610         kfree(link->wr_tx_mask);
 611 no_mem_wr_rx_sges:
 612         kfree(link->wr_rx_sges);
 613 no_mem_wr_tx_sges:
 614         kfree(link->wr_tx_sges);
 615 no_mem_wr_rx_ibs:
 616         kfree(link->wr_rx_ibs);
 617 no_mem_wr_tx_ibs:
 618         kfree(link->wr_tx_ibs);
 619 no_mem_wr_rx_bufs:
 620         kfree(link->wr_rx_bufs);
 621 no_mem_wr_tx_bufs:
 622         kfree(link->wr_tx_bufs);
 623 no_mem:
 624         return -ENOMEM;
 625 }
 626
 627 void smc_wr_remove_dev(struct smc_ib_device *smcibdev)
 628 {
 629         tasklet_kill(&smcibdev->recv_tasklet);
 630         tasklet_kill(&smcibdev->send_tasklet);
 631 }
 632
 633 void smc_wr_add_dev(struct smc_ib_device *smcibdev)
 634 {
 635         tasklet_init(&smcibdev->recv_tasklet, smc_wr_rx_tasklet_fn,
 636                      (unsigned long)smcibdev);
 637         tasklet_init(&smcibdev->send_tasklet, smc_wr_tx_tasklet_fn,
 638                      (unsigned long)smcibdev);
 639 }
 640
 641 int smc_wr_create_link(struct smc_link *lnk)
 642 {
 643         struct ib_device *ibdev = lnk->smcibdev->ibdev;
 644         int rc = 0;
 645
 646         smc_wr_tx_set_wr_id(&lnk->wr_tx_id, 0);
 647         lnk->wr_rx_id = 0;
 648         lnk->wr_rx_dma_addr = ib_dma_map_single(
 649                 ibdev, lnk->wr_rx_bufs, SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
 650                 DMA_FROM_DEVICE);
 651         if (ib_dma_mapping_error(ibdev, lnk->wr_rx_dma_addr)) {
 652                 lnk->wr_rx_dma_addr = 0;
 653                 rc = -EIO;
 654                 goto out;
 655         }
 656         lnk->wr_tx_dma_addr = ib_dma_map_single(
 657                 ibdev, lnk->wr_tx_bufs, SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
 658                 DMA_TO_DEVICE);
 659         if (ib_dma_mapping_error(ibdev, lnk->wr_tx_dma_addr)) {
 660                 rc = -EIO;
 661                 goto dma_unmap;
 662         }
 663         smc_wr_init_sge(lnk);
 664         memset(lnk->wr_tx_mask, 0,
 665                BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
 666         init_waitqueue_head(&lnk->wr_tx_wait);
 667         init_waitqueue_head(&lnk->wr_reg_wait);
 668         return rc;
 669
 670 dma_unmap:
 671         ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
 672                             SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
 673                             DMA_FROM_DEVICE);
 674         lnk->wr_rx_dma_addr = 0;
 675 out:
 676         return rc;
 677 }