drivers/net/mlx5/mlx5_rxtx.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright 2015 6WIND S.A.
   5  *   Copyright 2015 Mellanox.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of 6WIND S.A. nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <assert.h>
  35 #include <stdint.h>
  36 #include <string.h>
  37 #include <stdlib.h>
  38
  39 /* Verbs header. */
  40 /* ISO C doesn't support unnamed structs/unions, disabling -pedantic. */
  41 #ifdef PEDANTIC
  42 #pragma GCC diagnostic ignored "-pedantic"
  43 #endif
  44 #include <infiniband/verbs.h>
  45 #ifdef PEDANTIC
  46 #pragma GCC diagnostic error "-pedantic"
  47 #endif
  48
  49 /* DPDK headers don't like -pedantic. */
  50 #ifdef PEDANTIC
  51 #pragma GCC diagnostic ignored "-pedantic"
  52 #endif
  53 #include <rte_mbuf.h>
  54 #include <rte_mempool.h>
  55 #include <rte_prefetch.h>
  56 #include <rte_common.h>
  57 #include <rte_branch_prediction.h>
  58 #ifdef PEDANTIC
  59 #pragma GCC diagnostic error "-pedantic"
  60 #endif
  61
  62 #include "mlx5.h"
  63 #include "mlx5_utils.h"
  64 #include "mlx5_rxtx.h"
  65 #include "mlx5_defs.h"
  66
  67 /**
  68  * Manage TX completions.
  69  *
  70  * When sending a burst, mlx5_tx_burst() posts several WRs.
  71  * To improve performance, a completion event is only required once every
  72  * MLX5_PMD_TX_PER_COMP_REQ sends. Doing so discards completion information
  73  * for other WRs, but this information would not be used anyway.
  74  *
  75  * @param txq
  76  *   Pointer to TX queue structure.
  77  *
  78  * @return
  79  *   0 on success, -1 on failure.
  80  */
  81 static int
  82 txq_complete(struct txq *txq)
  83 {
  84         unsigned int elts_comp = txq->elts_comp;
  85         unsigned int elts_tail = txq->elts_tail;
  86         const unsigned int elts_n = txq->elts_n;
  87         int wcs_n;
  88
  89         if (unlikely(elts_comp == 0))
  90                 return 0;
  91 #ifdef DEBUG_SEND
  92         DEBUG("%p: processing %u work requests completions",
  93               (void *)txq, elts_comp);
  94 #endif
  95         wcs_n = txq->if_cq->poll_cnt(txq->cq, elts_comp);
  96         if (unlikely(wcs_n == 0))
  97                 return 0;
  98         if (unlikely(wcs_n < 0)) {
  99                 DEBUG("%p: ibv_poll_cq() failed (wcs_n=%d)",
 100                       (void *)txq, wcs_n);
 101                 return -1;
 102         }
 103         elts_comp -= wcs_n;
 104         assert(elts_comp <= txq->elts_comp);
 105         /*
 106          * Assume WC status is successful as nothing can be done about it
 107          * anyway.
 108          */
 109         elts_tail += wcs_n * txq->elts_comp_cd_init;
 110         if (elts_tail >= elts_n)
 111                 elts_tail -= elts_n;
 112         txq->elts_tail = elts_tail;
 113         txq->elts_comp = elts_comp;
 114         return 0;
 115 }
 116
 117 /**
 118  * Get Memory Region (MR) <-> Memory Pool (MP) association from txq->mp2mr[].
 119  * Add MP to txq->mp2mr[] if it's not registered yet. If mp2mr[] is full,
 120  * remove an entry first.
 121  *
 122  * @param txq
 123  *   Pointer to TX queue structure.
 124  * @param[in] mp
 125  *   Memory Pool for which a Memory Region lkey must be returned.
 126  *
 127  * @return
 128  *   mr->lkey on success, (uint32_t)-1 on failure.
 129  */
 130 static uint32_t
 131 txq_mp2mr(struct txq *txq, struct rte_mempool *mp)
 132 {
 133         unsigned int i;
 134         struct ibv_mr *mr;
 135
 136         for (i = 0; (i != RTE_DIM(txq->mp2mr)); ++i) {
 137                 if (unlikely(txq->mp2mr[i].mp == NULL)) {
 138                         /* Unknown MP, add a new MR for it. */
 139                         break;
 140                 }
 141                 if (txq->mp2mr[i].mp == mp) {
 142                         assert(txq->mp2mr[i].lkey != (uint32_t)-1);
 143                         assert(txq->mp2mr[i].mr->lkey == txq->mp2mr[i].lkey);
 144                         return txq->mp2mr[i].lkey;
 145                 }
 146         }
 147         /* Add a new entry, register MR first. */
 148         DEBUG("%p: discovered new memory pool %p", (void *)txq, (void *)mp);
 149         mr = ibv_reg_mr(txq->priv->pd,
 150                         (void *)mp->elt_va_start,
 151                         (mp->elt_va_end - mp->elt_va_start),
 152                         (IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE));
 153         if (unlikely(mr == NULL)) {
 154                 DEBUG("%p: unable to configure MR, ibv_reg_mr() failed.",
 155                       (void *)txq);
 156                 return (uint32_t)-1;
 157         }
 158         if (unlikely(i == RTE_DIM(txq->mp2mr))) {
 159                 /* Table is full, remove oldest entry. */
 160                 DEBUG("%p: MR <-> MP table full, dropping oldest entry.",
 161                       (void *)txq);
 162                 --i;
 163                 claim_zero(ibv_dereg_mr(txq->mp2mr[i].mr));
 164                 memmove(&txq->mp2mr[0], &txq->mp2mr[1],
 165                         (sizeof(txq->mp2mr) - sizeof(txq->mp2mr[0])));
 166         }
 167         /* Store the new entry. */
 168         txq->mp2mr[i].mp = mp;
 169         txq->mp2mr[i].mr = mr;
 170         txq->mp2mr[i].lkey = mr->lkey;
 171         DEBUG("%p: new MR lkey for MP %p: 0x%08" PRIu32,
 172               (void *)txq, (void *)mp, txq->mp2mr[i].lkey);
 173         return txq->mp2mr[i].lkey;
 174 }
 175
 176 #if MLX5_PMD_SGE_WR_N > 1
 177
 178 /**
 179  * Copy scattered mbuf contents to a single linear buffer.
 180  *
 181  * @param[out] linear
 182  *   Linear output buffer.
 183  * @param[in] buf
 184  *   Scattered input buffer.
 185  *
 186  * @return
 187  *   Number of bytes copied to the output buffer or 0 if not large enough.
 188  */
 189 static unsigned int
 190 linearize_mbuf(linear_t *linear, struct rte_mbuf *buf)
 191 {
 192         unsigned int size = 0;
 193         unsigned int offset;
 194
 195         do {
 196                 unsigned int len = DATA_LEN(buf);
 197
 198                 offset = size;
 199                 size += len;
 200                 if (unlikely(size > sizeof(*linear)))
 201                         return 0;
 202                 memcpy(&(*linear)[offset],
 203                        rte_pktmbuf_mtod(buf, uint8_t *),
 204                        len);
 205                 buf = NEXT(buf);
 206         } while (buf != NULL);
 207         return size;
 208 }
 209
 210 /**
 211  * Handle scattered buffers for mlx5_tx_burst().
 212  *
 213  * @param txq
 214  *   TX queue structure.
 215  * @param segs
 216  *   Number of segments in buf.
 217  * @param elt
 218  *   TX queue element to fill.
 219  * @param[in] buf
 220  *   Buffer to process.
 221  * @param elts_head
 222  *   Index of the linear buffer to use if necessary (normally txq->elts_head).
 223  * @param[out] sges
 224  *   Array filled with SGEs on success.
 225  *
 226  * @return
 227  *   A structure containing the processed packet size in bytes and the
 228  *   number of SGEs. Both fields are set to (unsigned int)-1 in case of
 229  *   failure.
 230  */
 231 static struct tx_burst_sg_ret {
 232         unsigned int length;
 233         unsigned int num;
 234 }
 235 tx_burst_sg(struct txq *txq, unsigned int segs, struct txq_elt *elt,
 236             struct rte_mbuf *buf, unsigned int elts_head,
 237             struct ibv_sge (*sges)[MLX5_PMD_SGE_WR_N])
 238 {
 239         unsigned int sent_size = 0;
 240         unsigned int j;
 241         int linearize = 0;
 242
 243         /* When there are too many segments, extra segments are
 244          * linearized in the last SGE. */
 245         if (unlikely(segs > RTE_DIM(*sges))) {
 246                 segs = (RTE_DIM(*sges) - 1);
 247                 linearize = 1;
 248         }
 249         /* Update element. */
 250         elt->buf = buf;
 251         /* Register segments as SGEs. */
 252         for (j = 0; (j != segs); ++j) {
 253                 struct ibv_sge *sge = &(*sges)[j];
 254                 uint32_t lkey;
 255
 256                 /* Retrieve Memory Region key for this memory pool. */
 257                 lkey = txq_mp2mr(txq, buf->pool);
 258                 if (unlikely(lkey == (uint32_t)-1)) {
 259                         /* MR does not exist. */
 260                         DEBUG("%p: unable to get MP <-> MR association",
 261                               (void *)txq);
 262                         /* Clean up TX element. */
 263                         elt->buf = NULL;
 264                         goto stop;
 265                 }
 266                 /* Update SGE. */
 267                 sge->addr = rte_pktmbuf_mtod(buf, uintptr_t);
 268                 if (txq->priv->vf)
 269                         rte_prefetch0((volatile void *)
 270                                       (uintptr_t)sge->addr);
 271                 sge->length = DATA_LEN(buf);
 272                 sge->lkey = lkey;
 273                 sent_size += sge->length;
 274                 buf = NEXT(buf);
 275         }
 276         /* If buf is not NULL here and is not going to be linearized,
 277          * nb_segs is not valid. */
 278         assert(j == segs);
 279         assert((buf == NULL) || (linearize));
 280         /* Linearize extra segments. */
 281         if (linearize) {
 282                 struct ibv_sge *sge = &(*sges)[segs];
 283                 linear_t *linear = &(*txq->elts_linear)[elts_head];
 284                 unsigned int size = linearize_mbuf(linear, buf);
 285
 286                 assert(segs == (RTE_DIM(*sges) - 1));
 287                 if (size == 0) {
 288                         /* Invalid packet. */
 289                         DEBUG("%p: packet too large to be linearized.",
 290                               (void *)txq);
 291                         /* Clean up TX element. */
 292                         elt->buf = NULL;
 293                         goto stop;
 294                 }
 295                 /* If MLX5_PMD_SGE_WR_N is 1, free mbuf immediately. */
 296                 if (RTE_DIM(*sges) == 1) {
 297                         do {
 298                                 struct rte_mbuf *next = NEXT(buf);
 299
 300                                 rte_pktmbuf_free_seg(buf);
 301                                 buf = next;
 302                         } while (buf != NULL);
 303                         elt->buf = NULL;
 304                 }
 305                 /* Update SGE. */
 306                 sge->addr = (uintptr_t)&(*linear)[0];
 307                 sge->length = size;
 308                 sge->lkey = txq->mr_linear->lkey;
 309                 sent_size += size;
 310         }
 311         return (struct tx_burst_sg_ret){
 312                 .length = sent_size,
 313                 .num = segs,
 314         };
 315 stop:
 316         return (struct tx_burst_sg_ret){
 317                 .length = -1,
 318                 .num = -1,
 319         };
 320 }
 321
 322 #endif /* MLX5_PMD_SGE_WR_N > 1 */
 323
 324 /**
 325  * DPDK callback for TX.
 326  *
 327  * @param dpdk_txq
 328  *   Generic pointer to TX queue structure.
 329  * @param[in] pkts
 330  *   Packets to transmit.
 331  * @param pkts_n
 332  *   Number of packets in array.
 333  *
 334  * @return
 335  *   Number of packets successfully transmitted (<= pkts_n).
 336  */
 337 uint16_t
 338 mlx5_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 339 {
 340         struct txq *txq = (struct txq *)dpdk_txq;
 341         unsigned int elts_head = txq->elts_head;
 342         const unsigned int elts_tail = txq->elts_tail;
 343         const unsigned int elts_n = txq->elts_n;
 344         unsigned int elts_comp_cd = txq->elts_comp_cd;
 345         unsigned int elts_comp = 0;
 346         unsigned int i;
 347         unsigned int max;
 348         int err;
 349
 350         assert(elts_comp_cd != 0);
 351         txq_complete(txq);
 352         max = (elts_n - (elts_head - elts_tail));
 353         if (max > elts_n)
 354                 max -= elts_n;
 355         assert(max >= 1);
 356         assert(max <= elts_n);
 357         /* Always leave one free entry in the ring. */
 358         --max;
 359         if (max == 0)
 360                 return 0;
 361         if (max > pkts_n)
 362                 max = pkts_n;
 363         for (i = 0; (i != max); ++i) {
 364                 struct rte_mbuf *buf = pkts[i];
 365                 unsigned int elts_head_next =
 366                         (((elts_head + 1) == elts_n) ? 0 : elts_head + 1);
 367                 struct txq_elt *elt_next = &(*txq->elts)[elts_head_next];
 368                 struct txq_elt *elt = &(*txq->elts)[elts_head];
 369                 unsigned int segs = NB_SEGS(buf);
 370                 uint32_t send_flags = 0;
 371
 372                 /* Clean up old buffer. */
 373                 if (likely(elt->buf != NULL)) {
 374                         struct rte_mbuf *tmp = elt->buf;
 375
 376                         /* Faster than rte_pktmbuf_free(). */
 377                         do {
 378                                 struct rte_mbuf *next = NEXT(tmp);
 379
 380                                 rte_pktmbuf_free_seg(tmp);
 381                                 tmp = next;
 382                         } while (tmp != NULL);
 383                 }
 384                 /* Request TX completion. */
 385                 if (unlikely(--elts_comp_cd == 0)) {
 386                         elts_comp_cd = txq->elts_comp_cd_init;
 387                         ++elts_comp;
 388                         send_flags |= IBV_EXP_QP_BURST_SIGNALED;
 389                 }
 390                 if (likely(segs == 1)) {
 391                         uintptr_t addr;
 392                         uint32_t length;
 393                         uint32_t lkey;
 394
 395                         /* Retrieve buffer information. */
 396                         addr = rte_pktmbuf_mtod(buf, uintptr_t);
 397                         length = DATA_LEN(buf);
 398                         /* Retrieve Memory Region key for this memory pool. */
 399                         lkey = txq_mp2mr(txq, buf->pool);
 400                         if (unlikely(lkey == (uint32_t)-1)) {
 401                                 /* MR does not exist. */
 402                                 DEBUG("%p: unable to get MP <-> MR"
 403                                       " association", (void *)txq);
 404                                 /* Clean up TX element. */
 405                                 elt->buf = NULL;
 406                                 goto stop;
 407                         }
 408                         /* Update element. */
 409                         elt->buf = buf;
 410                         if (txq->priv->vf)
 411                                 rte_prefetch0((volatile void *)
 412                                               (uintptr_t)addr);
 413                         RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
 414                         /* Put packet into send queue. */
 415 #if MLX5_PMD_MAX_INLINE > 0
 416                         if (length <= txq->max_inline)
 417                                 err = txq->if_qp->send_pending_inline
 418                                         (txq->qp,
 419                                          (void *)addr,
 420                                          length,
 421                                          send_flags);
 422                         else
 423 #endif
 424                                 err = txq->if_qp->send_pending
 425                                         (txq->qp,
 426                                          addr,
 427                                          length,
 428                                          lkey,
 429                                          send_flags);
 430                         if (unlikely(err))
 431                                 goto stop;
 432                 } else {
 433 #if MLX5_PMD_SGE_WR_N > 1
 434                         struct ibv_sge sges[MLX5_PMD_SGE_WR_N];
 435                         struct tx_burst_sg_ret ret;
 436
 437                         ret = tx_burst_sg(txq, segs, elt, buf, elts_head,
 438                                           &sges);
 439                         if (ret.length == (unsigned int)-1)
 440                                 goto stop;
 441                         RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
 442                         /* Put SG list into send queue. */
 443                         err = txq->if_qp->send_pending_sg_list
 444                                 (txq->qp,
 445                                  sges,
 446                                  ret.num,
 447                                  send_flags);
 448                         if (unlikely(err))
 449                                 goto stop;
 450 #else /* MLX5_PMD_SGE_WR_N > 1 */
 451                         DEBUG("%p: TX scattered buffers support not"
 452                               " compiled in", (void *)txq);
 453                         goto stop;
 454 #endif /* MLX5_PMD_SGE_WR_N > 1 */
 455                 }
 456                 elts_head = elts_head_next;
 457         }
 458 stop:
 459         /* Take a shortcut if nothing must be sent. */
 460         if (unlikely(i == 0))
 461                 return 0;
 462         /* Ring QP doorbell. */
 463         err = txq->if_qp->send_flush(txq->qp);
 464         if (unlikely(err)) {
 465                 /* A nonzero value is not supposed to be returned.
 466                  * Nothing can be done about it. */
 467                 DEBUG("%p: send_flush() failed with error %d",
 468                       (void *)txq, err);
 469         }
 470         txq->elts_head = elts_head;
 471         txq->elts_comp += elts_comp;
 472         txq->elts_comp_cd = elts_comp_cd;
 473         return i;
 474 }
 475
 476 /**
 477  * DPDK callback for RX with scattered packets support.
 478  *
 479  * @param dpdk_rxq
 480  *   Generic pointer to RX queue structure.
 481  * @param[out] pkts
 482  *   Array to store received packets.
 483  * @param pkts_n
 484  *   Maximum number of packets in array.
 485  *
 486  * @return
 487  *   Number of packets successfully received (<= pkts_n).
 488  */
 489 uint16_t
 490 mlx5_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 491 {
 492         struct rxq *rxq = (struct rxq *)dpdk_rxq;
 493         struct rxq_elt_sp (*elts)[rxq->elts_n] = rxq->elts.sp;
 494         const unsigned int elts_n = rxq->elts_n;
 495         unsigned int elts_head = rxq->elts_head;
 496         struct ibv_recv_wr head;
 497         struct ibv_recv_wr **next = &head.next;
 498         struct ibv_recv_wr *bad_wr;
 499         unsigned int i;
 500         unsigned int pkts_ret = 0;
 501         int ret;
 502
 503         if (unlikely(!rxq->sp))
 504                 return mlx5_rx_burst(dpdk_rxq, pkts, pkts_n);
 505         if (unlikely(elts == NULL)) /* See RTE_DEV_CMD_SET_MTU. */
 506                 return 0;
 507         for (i = 0; (i != pkts_n); ++i) {
 508                 struct rxq_elt_sp *elt = &(*elts)[elts_head];
 509                 struct ibv_recv_wr *wr = &elt->wr;
 510                 uint64_t wr_id = wr->wr_id;
 511                 unsigned int len;
 512                 unsigned int pkt_buf_len;
 513                 struct rte_mbuf *pkt_buf = NULL; /* Buffer returned in pkts. */
 514                 struct rte_mbuf **pkt_buf_next = &pkt_buf;
 515                 unsigned int seg_headroom = RTE_PKTMBUF_HEADROOM;
 516                 unsigned int j = 0;
 517                 uint32_t flags;
 518
 519                 /* Sanity checks. */
 520 #ifdef NDEBUG
 521                 (void)wr_id;
 522 #endif
 523                 assert(wr_id < rxq->elts_n);
 524                 assert(wr->sg_list == elt->sges);
 525                 assert(wr->num_sge == RTE_DIM(elt->sges));
 526                 assert(elts_head < rxq->elts_n);
 527                 assert(rxq->elts_head < rxq->elts_n);
 528                 ret = rxq->if_cq->poll_length_flags(rxq->cq, NULL, NULL,
 529                                                     &flags);
 530                 if (unlikely(ret < 0)) {
 531                         struct ibv_wc wc;
 532                         int wcs_n;
 533
 534                         DEBUG("rxq=%p, poll_length() failed (ret=%d)",
 535                               (void *)rxq, ret);
 536                         /* ibv_poll_cq() must be used in case of failure. */
 537                         wcs_n = ibv_poll_cq(rxq->cq, 1, &wc);
 538                         if (unlikely(wcs_n == 0))
 539                                 break;
 540                         if (unlikely(wcs_n < 0)) {
 541                                 DEBUG("rxq=%p, ibv_poll_cq() failed (wcs_n=%d)",
 542                                       (void *)rxq, wcs_n);
 543                                 break;
 544                         }
 545                         assert(wcs_n == 1);
 546                         if (unlikely(wc.status != IBV_WC_SUCCESS)) {
 547                                 /* Whatever, just repost the offending WR. */
 548                                 DEBUG("rxq=%p, wr_id=%" PRIu64 ": bad work"
 549                                       " completion status (%d): %s",
 550                                       (void *)rxq, wc.wr_id, wc.status,
 551                                       ibv_wc_status_str(wc.status));
 552                                 /* Link completed WRs together for repost. */
 553                                 *next = wr;
 554                                 next = &wr->next;
 555                                 goto repost;
 556                         }
 557                         ret = wc.byte_len;
 558                 }
 559                 if (ret == 0)
 560                         break;
 561                 len = ret;
 562                 pkt_buf_len = len;
 563                 /* Link completed WRs together for repost. */
 564                 *next = wr;
 565                 next = &wr->next;
 566                 /*
 567                  * Replace spent segments with new ones, concatenate and
 568                  * return them as pkt_buf.
 569                  */
 570                 while (1) {
 571                         struct ibv_sge *sge = &elt->sges[j];
 572                         struct rte_mbuf *seg = elt->bufs[j];
 573                         struct rte_mbuf *rep;
 574                         unsigned int seg_tailroom;
 575
 576                         /*
 577                          * Fetch initial bytes of packet descriptor into a
 578                          * cacheline while allocating rep.
 579                          */
 580                         rte_prefetch0(seg);
 581                         rep = __rte_mbuf_raw_alloc(rxq->mp);
 582                         if (unlikely(rep == NULL)) {
 583                                 /*
 584                                  * Unable to allocate a replacement mbuf,
 585                                  * repost WR.
 586                                  */
 587                                 DEBUG("rxq=%p, wr_id=%" PRIu64 ":"
 588                                       " can't allocate a new mbuf",
 589                                       (void *)rxq, wr_id);
 590                                 if (pkt_buf != NULL) {
 591                                         *pkt_buf_next = NULL;
 592                                         rte_pktmbuf_free(pkt_buf);
 593                                 }
 594                                 /* Increment out of memory counters. */
 595                                 ++rxq->priv->dev->data->rx_mbuf_alloc_failed;
 596                                 goto repost;
 597                         }
 598 #ifndef NDEBUG
 599                         /* Poison user-modifiable fields in rep. */
 600                         NEXT(rep) = (void *)((uintptr_t)-1);
 601                         SET_DATA_OFF(rep, 0xdead);
 602                         DATA_LEN(rep) = 0xd00d;
 603                         PKT_LEN(rep) = 0xdeadd00d;
 604                         NB_SEGS(rep) = 0x2a;
 605                         PORT(rep) = 0x2a;
 606                         rep->ol_flags = -1;
 607 #endif
 608                         assert(rep->buf_len == seg->buf_len);
 609                         assert(rep->buf_len == rxq->mb_len);
 610                         /* Reconfigure sge to use rep instead of seg. */
 611                         assert(sge->lkey == rxq->mr->lkey);
 612                         sge->addr = ((uintptr_t)rep->buf_addr + seg_headroom);
 613                         elt->bufs[j] = rep;
 614                         ++j;
 615                         /* Update pkt_buf if it's the first segment, or link
 616                          * seg to the previous one and update pkt_buf_next. */
 617                         *pkt_buf_next = seg;
 618                         pkt_buf_next = &NEXT(seg);
 619                         /* Update seg information. */
 620                         seg_tailroom = (seg->buf_len - seg_headroom);
 621                         assert(sge->length == seg_tailroom);
 622                         SET_DATA_OFF(seg, seg_headroom);
 623                         if (likely(len <= seg_tailroom)) {
 624                                 /* Last segment. */
 625                                 DATA_LEN(seg) = len;
 626                                 PKT_LEN(seg) = len;
 627                                 /* Sanity check. */
 628                                 assert(rte_pktmbuf_headroom(seg) ==
 629                                        seg_headroom);
 630                                 assert(rte_pktmbuf_tailroom(seg) ==
 631                                        (seg_tailroom - len));
 632                                 break;
 633                         }
 634                         DATA_LEN(seg) = seg_tailroom;
 635                         PKT_LEN(seg) = seg_tailroom;
 636                         /* Sanity check. */
 637                         assert(rte_pktmbuf_headroom(seg) == seg_headroom);
 638                         assert(rte_pktmbuf_tailroom(seg) == 0);
 639                         /* Fix len and clear headroom for next segments. */
 640                         len -= seg_tailroom;
 641                         seg_headroom = 0;
 642                 }
 643                 /* Update head and tail segments. */
 644                 *pkt_buf_next = NULL;
 645                 assert(pkt_buf != NULL);
 646                 assert(j != 0);
 647                 NB_SEGS(pkt_buf) = j;
 648                 PORT(pkt_buf) = rxq->port_id;
 649                 PKT_LEN(pkt_buf) = pkt_buf_len;
 650
 651                 /* Return packet. */
 652                 *(pkts++) = pkt_buf;
 653                 ++pkts_ret;
 654 repost:
 655                 if (++elts_head >= elts_n)
 656                         elts_head = 0;
 657                 continue;
 658         }
 659         if (unlikely(i == 0))
 660                 return 0;
 661         *next = NULL;
 662         /* Repost WRs. */
 663 #ifdef DEBUG_RECV
 664         DEBUG("%p: reposting %d WRs", (void *)rxq, i);
 665 #endif
 666         ret = ibv_post_recv(rxq->qp, head.next, &bad_wr);
 667         if (unlikely(ret)) {
 668                 /* Inability to repost WRs is fatal. */
 669                 DEBUG("%p: ibv_post_recv(): failed for WR %p: %s",
 670                       (void *)rxq->priv,
 671                       (void *)bad_wr,
 672                       strerror(ret));
 673                 abort();
 674         }
 675         rxq->elts_head = elts_head;
 676         return pkts_ret;
 677 }
 678
 679 /**
 680  * DPDK callback for RX.
 681  *
 682  * The following function is the same as mlx5_rx_burst_sp(), except it doesn't
 683  * manage scattered packets. Improves performance when MRU is lower than the
 684  * size of the first segment.
 685  *
 686  * @param dpdk_rxq
 687  *   Generic pointer to RX queue structure.
 688  * @param[out] pkts
 689  *   Array to store received packets.
 690  * @param pkts_n
 691  *   Maximum number of packets in array.
 692  *
 693  * @return
 694  *   Number of packets successfully received (<= pkts_n).
 695  */
 696 uint16_t
 697 mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 698 {
 699         struct rxq *rxq = (struct rxq *)dpdk_rxq;
 700         struct rxq_elt (*elts)[rxq->elts_n] = rxq->elts.no_sp;
 701         const unsigned int elts_n = rxq->elts_n;
 702         unsigned int elts_head = rxq->elts_head;
 703         struct ibv_sge sges[pkts_n];
 704         unsigned int i;
 705         unsigned int pkts_ret = 0;
 706         int ret;
 707
 708         if (unlikely(rxq->sp))
 709                 return mlx5_rx_burst_sp(dpdk_rxq, pkts, pkts_n);
 710         for (i = 0; (i != pkts_n); ++i) {
 711                 struct rxq_elt *elt = &(*elts)[elts_head];
 712                 struct ibv_recv_wr *wr = &elt->wr;
 713                 uint64_t wr_id = wr->wr_id;
 714                 unsigned int len;
 715                 struct rte_mbuf *seg = (void *)((uintptr_t)elt->sge.addr -
 716                         WR_ID(wr_id).offset);
 717                 struct rte_mbuf *rep;
 718                 uint32_t flags;
 719
 720                 /* Sanity checks. */
 721                 assert(WR_ID(wr_id).id < rxq->elts_n);
 722                 assert(wr->sg_list == &elt->sge);
 723                 assert(wr->num_sge == 1);
 724                 assert(elts_head < rxq->elts_n);
 725                 assert(rxq->elts_head < rxq->elts_n);
 726                 /*
 727                  * Fetch initial bytes of packet descriptor into a
 728                  * cacheline while allocating rep.
 729                  */
 730                 rte_prefetch0(seg);
 731                 rte_prefetch0(&seg->cacheline1);
 732                 ret = rxq->if_cq->poll_length_flags(rxq->cq, NULL, NULL,
 733                                                     &flags);
 734                 if (unlikely(ret < 0)) {
 735                         struct ibv_wc wc;
 736                         int wcs_n;
 737
 738                         DEBUG("rxq=%p, poll_length() failed (ret=%d)",
 739                               (void *)rxq, ret);
 740                         /* ibv_poll_cq() must be used in case of failure. */
 741                         wcs_n = ibv_poll_cq(rxq->cq, 1, &wc);
 742                         if (unlikely(wcs_n == 0))
 743                                 break;
 744                         if (unlikely(wcs_n < 0)) {
 745                                 DEBUG("rxq=%p, ibv_poll_cq() failed (wcs_n=%d)",
 746                                       (void *)rxq, wcs_n);
 747                                 break;
 748                         }
 749                         assert(wcs_n == 1);
 750                         if (unlikely(wc.status != IBV_WC_SUCCESS)) {
 751                                 /* Whatever, just repost the offending WR. */
 752                                 DEBUG("rxq=%p, wr_id=%" PRIu64 ": bad work"
 753                                       " completion status (%d): %s",
 754                                       (void *)rxq, wc.wr_id, wc.status,
 755                                       ibv_wc_status_str(wc.status));
 756                                 /* Add SGE to array for repost. */
 757                                 sges[i] = elt->sge;
 758                                 goto repost;
 759                         }
 760                         ret = wc.byte_len;
 761                 }
 762                 if (ret == 0)
 763                         break;
 764                 len = ret;
 765                 rep = __rte_mbuf_raw_alloc(rxq->mp);
 766                 if (unlikely(rep == NULL)) {
 767                         /*
 768                          * Unable to allocate a replacement mbuf,
 769                          * repost WR.
 770                          */
 771                         DEBUG("rxq=%p, wr_id=%" PRIu32 ":"
 772                               " can't allocate a new mbuf",
 773                               (void *)rxq, WR_ID(wr_id).id);
 774                         /* Increment out of memory counters. */
 775                         ++rxq->priv->dev->data->rx_mbuf_alloc_failed;
 776                         goto repost;
 777                 }
 778
 779                 /* Reconfigure sge to use rep instead of seg. */
 780                 elt->sge.addr = (uintptr_t)rep->buf_addr + RTE_PKTMBUF_HEADROOM;
 781                 assert(elt->sge.lkey == rxq->mr->lkey);
 782                 WR_ID(wr->wr_id).offset =
 783                         (((uintptr_t)rep->buf_addr + RTE_PKTMBUF_HEADROOM) -
 784                          (uintptr_t)rep);
 785                 assert(WR_ID(wr->wr_id).id == WR_ID(wr_id).id);
 786
 787                 /* Add SGE to array for repost. */
 788                 sges[i] = elt->sge;
 789
 790                 /* Update seg information. */
 791                 SET_DATA_OFF(seg, RTE_PKTMBUF_HEADROOM);
 792                 NB_SEGS(seg) = 1;
 793                 PORT(seg) = rxq->port_id;
 794                 NEXT(seg) = NULL;
 795                 PKT_LEN(seg) = len;
 796                 DATA_LEN(seg) = len;
 797
 798                 /* Return packet. */
 799                 *(pkts++) = seg;
 800                 ++pkts_ret;
 801 repost:
 802                 if (++elts_head >= elts_n)
 803                         elts_head = 0;
 804                 continue;
 805         }
 806         if (unlikely(i == 0))
 807                 return 0;
 808         /* Repost WRs. */
 809 #ifdef DEBUG_RECV
 810         DEBUG("%p: reposting %u WRs", (void *)rxq, i);
 811 #endif
 812         ret = rxq->if_qp->recv_burst(rxq->qp, sges, i);
 813         if (unlikely(ret)) {
 814                 /* Inability to repost WRs is fatal. */
 815                 DEBUG("%p: recv_burst(): failed (ret=%d)",
 816                       (void *)rxq->priv,
 817                       ret);
 818                 abort();
 819         }
 820         rxq->elts_head = elts_head;
 821         return pkts_ret;
 822 }
 823
 824 /**
 825  * Dummy DPDK callback for TX.
 826  *
 827  * This function is used to temporarily replace the real callback during
 828  * unsafe control operations on the queue, or in case of error.
 829  *
 830  * @param dpdk_txq
 831  *   Generic pointer to TX queue structure.
 832  * @param[in] pkts
 833  *   Packets to transmit.
 834  * @param pkts_n
 835  *   Number of packets in array.
 836  *
 837  * @return
 838  *   Number of packets successfully transmitted (<= pkts_n).
 839  */
 840 uint16_t
 841 removed_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 842 {
 843         (void)dpdk_txq;
 844         (void)pkts;
 845         (void)pkts_n;
 846         return 0;
 847 }
 848
 849 /**
 850  * Dummy DPDK callback for RX.
 851  *
 852  * This function is used to temporarily replace the real callback during
 853  * unsafe control operations on the queue, or in case of error.
 854  *
 855  * @param dpdk_rxq
 856  *   Generic pointer to RX queue structure.
 857  * @param[out] pkts
 858  *   Array to store received packets.
 859  * @param pkts_n
 860  *   Maximum number of packets in array.
 861  *
 862  * @return
 863  *   Number of packets successfully received (<= pkts_n).
 864  */
 865 uint16_t
 866 removed_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 867 {
 868         (void)dpdk_rxq;
 869         (void)pkts;
 870         (void)pkts_n;
 871         return 0;
 872 }