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 #ifdef MLX5_PMD_SOFT_COUNTERS
 371                 unsigned int sent_size = 0;
 372 #endif
 373                 uint32_t send_flags = 0;
 374
 375                 /* Clean up old buffer. */
 376                 if (likely(elt->buf != NULL)) {
 377                         struct rte_mbuf *tmp = elt->buf;
 378
 379                         /* Faster than rte_pktmbuf_free(). */
 380                         do {
 381                                 struct rte_mbuf *next = NEXT(tmp);
 382
 383                                 rte_pktmbuf_free_seg(tmp);
 384                                 tmp = next;
 385                         } while (tmp != NULL);
 386                 }
 387                 /* Request TX completion. */
 388                 if (unlikely(--elts_comp_cd == 0)) {
 389                         elts_comp_cd = txq->elts_comp_cd_init;
 390                         ++elts_comp;
 391                         send_flags |= IBV_EXP_QP_BURST_SIGNALED;
 392                 }
 393                 if (likely(segs == 1)) {
 394                         uintptr_t addr;
 395                         uint32_t length;
 396                         uint32_t lkey;
 397
 398                         /* Retrieve buffer information. */
 399                         addr = rte_pktmbuf_mtod(buf, uintptr_t);
 400                         length = DATA_LEN(buf);
 401                         /* Retrieve Memory Region key for this memory pool. */
 402                         lkey = txq_mp2mr(txq, buf->pool);
 403                         if (unlikely(lkey == (uint32_t)-1)) {
 404                                 /* MR does not exist. */
 405                                 DEBUG("%p: unable to get MP <-> MR"
 406                                       " association", (void *)txq);
 407                                 /* Clean up TX element. */
 408                                 elt->buf = NULL;
 409                                 goto stop;
 410                         }
 411                         /* Update element. */
 412                         elt->buf = buf;
 413                         if (txq->priv->vf)
 414                                 rte_prefetch0((volatile void *)
 415                                               (uintptr_t)addr);
 416                         RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
 417                         /* Put packet into send queue. */
 418 #if MLX5_PMD_MAX_INLINE > 0
 419                         if (length <= txq->max_inline)
 420                                 err = txq->if_qp->send_pending_inline
 421                                         (txq->qp,
 422                                          (void *)addr,
 423                                          length,
 424                                          send_flags);
 425                         else
 426 #endif
 427                                 err = txq->if_qp->send_pending
 428                                         (txq->qp,
 429                                          addr,
 430                                          length,
 431                                          lkey,
 432                                          send_flags);
 433                         if (unlikely(err))
 434                                 goto stop;
 435 #ifdef MLX5_PMD_SOFT_COUNTERS
 436                         sent_size += length;
 437 #endif
 438                 } else {
 439 #if MLX5_PMD_SGE_WR_N > 1
 440                         struct ibv_sge sges[MLX5_PMD_SGE_WR_N];
 441                         struct tx_burst_sg_ret ret;
 442
 443                         ret = tx_burst_sg(txq, segs, elt, buf, elts_head,
 444                                           &sges);
 445                         if (ret.length == (unsigned int)-1)
 446                                 goto stop;
 447                         RTE_MBUF_PREFETCH_TO_FREE(elt_next->buf);
 448                         /* Put SG list into send queue. */
 449                         err = txq->if_qp->send_pending_sg_list
 450                                 (txq->qp,
 451                                  sges,
 452                                  ret.num,
 453                                  send_flags);
 454                         if (unlikely(err))
 455                                 goto stop;
 456 #ifdef MLX5_PMD_SOFT_COUNTERS
 457                         sent_size += ret.length;
 458 #endif
 459 #else /* MLX5_PMD_SGE_WR_N > 1 */
 460                         DEBUG("%p: TX scattered buffers support not"
 461                               " compiled in", (void *)txq);
 462                         goto stop;
 463 #endif /* MLX5_PMD_SGE_WR_N > 1 */
 464                 }
 465                 elts_head = elts_head_next;
 466 #ifdef MLX5_PMD_SOFT_COUNTERS
 467                 /* Increment sent bytes counter. */
 468                 txq->stats.obytes += sent_size;
 469 #endif
 470         }
 471 stop:
 472         /* Take a shortcut if nothing must be sent. */
 473         if (unlikely(i == 0))
 474                 return 0;
 475 #ifdef MLX5_PMD_SOFT_COUNTERS
 476         /* Increment sent packets counter. */
 477         txq->stats.opackets += i;
 478 #endif
 479         /* Ring QP doorbell. */
 480         err = txq->if_qp->send_flush(txq->qp);
 481         if (unlikely(err)) {
 482                 /* A nonzero value is not supposed to be returned.
 483                  * Nothing can be done about it. */
 484                 DEBUG("%p: send_flush() failed with error %d",
 485                       (void *)txq, err);
 486         }
 487         txq->elts_head = elts_head;
 488         txq->elts_comp += elts_comp;
 489         txq->elts_comp_cd = elts_comp_cd;
 490         return i;
 491 }
 492
 493 /**
 494  * DPDK callback for RX with scattered packets support.
 495  *
 496  * @param dpdk_rxq
 497  *   Generic pointer to RX queue structure.
 498  * @param[out] pkts
 499  *   Array to store received packets.
 500  * @param pkts_n
 501  *   Maximum number of packets in array.
 502  *
 503  * @return
 504  *   Number of packets successfully received (<= pkts_n).
 505  */
 506 uint16_t
 507 mlx5_rx_burst_sp(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 508 {
 509         struct rxq *rxq = (struct rxq *)dpdk_rxq;
 510         struct rxq_elt_sp (*elts)[rxq->elts_n] = rxq->elts.sp;
 511         const unsigned int elts_n = rxq->elts_n;
 512         unsigned int elts_head = rxq->elts_head;
 513         struct ibv_recv_wr head;
 514         struct ibv_recv_wr **next = &head.next;
 515         struct ibv_recv_wr *bad_wr;
 516         unsigned int i;
 517         unsigned int pkts_ret = 0;
 518         int ret;
 519
 520         if (unlikely(!rxq->sp))
 521                 return mlx5_rx_burst(dpdk_rxq, pkts, pkts_n);
 522         if (unlikely(elts == NULL)) /* See RTE_DEV_CMD_SET_MTU. */
 523                 return 0;
 524         for (i = 0; (i != pkts_n); ++i) {
 525                 struct rxq_elt_sp *elt = &(*elts)[elts_head];
 526                 struct ibv_recv_wr *wr = &elt->wr;
 527                 uint64_t wr_id = wr->wr_id;
 528                 unsigned int len;
 529                 unsigned int pkt_buf_len;
 530                 struct rte_mbuf *pkt_buf = NULL; /* Buffer returned in pkts. */
 531                 struct rte_mbuf **pkt_buf_next = &pkt_buf;
 532                 unsigned int seg_headroom = RTE_PKTMBUF_HEADROOM;
 533                 unsigned int j = 0;
 534                 uint32_t flags;
 535
 536                 /* Sanity checks. */
 537 #ifdef NDEBUG
 538                 (void)wr_id;
 539 #endif
 540                 assert(wr_id < rxq->elts_n);
 541                 assert(wr->sg_list == elt->sges);
 542                 assert(wr->num_sge == RTE_DIM(elt->sges));
 543                 assert(elts_head < rxq->elts_n);
 544                 assert(rxq->elts_head < rxq->elts_n);
 545                 ret = rxq->if_cq->poll_length_flags(rxq->cq, NULL, NULL,
 546                                                     &flags);
 547                 if (unlikely(ret < 0)) {
 548                         struct ibv_wc wc;
 549                         int wcs_n;
 550
 551                         DEBUG("rxq=%p, poll_length() failed (ret=%d)",
 552                               (void *)rxq, ret);
 553                         /* ibv_poll_cq() must be used in case of failure. */
 554                         wcs_n = ibv_poll_cq(rxq->cq, 1, &wc);
 555                         if (unlikely(wcs_n == 0))
 556                                 break;
 557                         if (unlikely(wcs_n < 0)) {
 558                                 DEBUG("rxq=%p, ibv_poll_cq() failed (wcs_n=%d)",
 559                                       (void *)rxq, wcs_n);
 560                                 break;
 561                         }
 562                         assert(wcs_n == 1);
 563                         if (unlikely(wc.status != IBV_WC_SUCCESS)) {
 564                                 /* Whatever, just repost the offending WR. */
 565                                 DEBUG("rxq=%p, wr_id=%" PRIu64 ": bad work"
 566                                       " completion status (%d): %s",
 567                                       (void *)rxq, wc.wr_id, wc.status,
 568                                       ibv_wc_status_str(wc.status));
 569 #ifdef MLX5_PMD_SOFT_COUNTERS
 570                                 /* Increment dropped packets counter. */
 571                                 ++rxq->stats.idropped;
 572 #endif
 573                                 /* Link completed WRs together for repost. */
 574                                 *next = wr;
 575                                 next = &wr->next;
 576                                 goto repost;
 577                         }
 578                         ret = wc.byte_len;
 579                 }
 580                 if (ret == 0)
 581                         break;
 582                 len = ret;
 583                 pkt_buf_len = len;
 584                 /* Link completed WRs together for repost. */
 585                 *next = wr;
 586                 next = &wr->next;
 587                 /*
 588                  * Replace spent segments with new ones, concatenate and
 589                  * return them as pkt_buf.
 590                  */
 591                 while (1) {
 592                         struct ibv_sge *sge = &elt->sges[j];
 593                         struct rte_mbuf *seg = elt->bufs[j];
 594                         struct rte_mbuf *rep;
 595                         unsigned int seg_tailroom;
 596
 597                         /*
 598                          * Fetch initial bytes of packet descriptor into a
 599                          * cacheline while allocating rep.
 600                          */
 601                         rte_prefetch0(seg);
 602                         rep = __rte_mbuf_raw_alloc(rxq->mp);
 603                         if (unlikely(rep == NULL)) {
 604                                 /*
 605                                  * Unable to allocate a replacement mbuf,
 606                                  * repost WR.
 607                                  */
 608                                 DEBUG("rxq=%p, wr_id=%" PRIu64 ":"
 609                                       " can't allocate a new mbuf",
 610                                       (void *)rxq, wr_id);
 611                                 if (pkt_buf != NULL) {
 612                                         *pkt_buf_next = NULL;
 613                                         rte_pktmbuf_free(pkt_buf);
 614                                 }
 615                                 /* Increment out of memory counters. */
 616                                 ++rxq->stats.rx_nombuf;
 617                                 ++rxq->priv->dev->data->rx_mbuf_alloc_failed;
 618                                 goto repost;
 619                         }
 620 #ifndef NDEBUG
 621                         /* Poison user-modifiable fields in rep. */
 622                         NEXT(rep) = (void *)((uintptr_t)-1);
 623                         SET_DATA_OFF(rep, 0xdead);
 624                         DATA_LEN(rep) = 0xd00d;
 625                         PKT_LEN(rep) = 0xdeadd00d;
 626                         NB_SEGS(rep) = 0x2a;
 627                         PORT(rep) = 0x2a;
 628                         rep->ol_flags = -1;
 629 #endif
 630                         assert(rep->buf_len == seg->buf_len);
 631                         assert(rep->buf_len == rxq->mb_len);
 632                         /* Reconfigure sge to use rep instead of seg. */
 633                         assert(sge->lkey == rxq->mr->lkey);
 634                         sge->addr = ((uintptr_t)rep->buf_addr + seg_headroom);
 635                         elt->bufs[j] = rep;
 636                         ++j;
 637                         /* Update pkt_buf if it's the first segment, or link
 638                          * seg to the previous one and update pkt_buf_next. */
 639                         *pkt_buf_next = seg;
 640                         pkt_buf_next = &NEXT(seg);
 641                         /* Update seg information. */
 642                         seg_tailroom = (seg->buf_len - seg_headroom);
 643                         assert(sge->length == seg_tailroom);
 644                         SET_DATA_OFF(seg, seg_headroom);
 645                         if (likely(len <= seg_tailroom)) {
 646                                 /* Last segment. */
 647                                 DATA_LEN(seg) = len;
 648                                 PKT_LEN(seg) = len;
 649                                 /* Sanity check. */
 650                                 assert(rte_pktmbuf_headroom(seg) ==
 651                                        seg_headroom);
 652                                 assert(rte_pktmbuf_tailroom(seg) ==
 653                                        (seg_tailroom - len));
 654                                 break;
 655                         }
 656                         DATA_LEN(seg) = seg_tailroom;
 657                         PKT_LEN(seg) = seg_tailroom;
 658                         /* Sanity check. */
 659                         assert(rte_pktmbuf_headroom(seg) == seg_headroom);
 660                         assert(rte_pktmbuf_tailroom(seg) == 0);
 661                         /* Fix len and clear headroom for next segments. */
 662                         len -= seg_tailroom;
 663                         seg_headroom = 0;
 664                 }
 665                 /* Update head and tail segments. */
 666                 *pkt_buf_next = NULL;
 667                 assert(pkt_buf != NULL);
 668                 assert(j != 0);
 669                 NB_SEGS(pkt_buf) = j;
 670                 PORT(pkt_buf) = rxq->port_id;
 671                 PKT_LEN(pkt_buf) = pkt_buf_len;
 672
 673                 /* Return packet. */
 674                 *(pkts++) = pkt_buf;
 675                 ++pkts_ret;
 676 #ifdef MLX5_PMD_SOFT_COUNTERS
 677                 /* Increment bytes counter. */
 678                 rxq->stats.ibytes += pkt_buf_len;
 679 #endif
 680 repost:
 681                 if (++elts_head >= elts_n)
 682                         elts_head = 0;
 683                 continue;
 684         }
 685         if (unlikely(i == 0))
 686                 return 0;
 687         *next = NULL;
 688         /* Repost WRs. */
 689 #ifdef DEBUG_RECV
 690         DEBUG("%p: reposting %d WRs", (void *)rxq, i);
 691 #endif
 692         ret = ibv_post_recv(rxq->qp, head.next, &bad_wr);
 693         if (unlikely(ret)) {
 694                 /* Inability to repost WRs is fatal. */
 695                 DEBUG("%p: ibv_post_recv(): failed for WR %p: %s",
 696                       (void *)rxq->priv,
 697                       (void *)bad_wr,
 698                       strerror(ret));
 699                 abort();
 700         }
 701         rxq->elts_head = elts_head;
 702 #ifdef MLX5_PMD_SOFT_COUNTERS
 703         /* Increment packets counter. */
 704         rxq->stats.ipackets += pkts_ret;
 705 #endif
 706         return pkts_ret;
 707 }
 708
 709 /**
 710  * DPDK callback for RX.
 711  *
 712  * The following function is the same as mlx5_rx_burst_sp(), except it doesn't
 713  * manage scattered packets. Improves performance when MRU is lower than the
 714  * size of the first segment.
 715  *
 716  * @param dpdk_rxq
 717  *   Generic pointer to RX queue structure.
 718  * @param[out] pkts
 719  *   Array to store received packets.
 720  * @param pkts_n
 721  *   Maximum number of packets in array.
 722  *
 723  * @return
 724  *   Number of packets successfully received (<= pkts_n).
 725  */
 726 uint16_t
 727 mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 728 {
 729         struct rxq *rxq = (struct rxq *)dpdk_rxq;
 730         struct rxq_elt (*elts)[rxq->elts_n] = rxq->elts.no_sp;
 731         const unsigned int elts_n = rxq->elts_n;
 732         unsigned int elts_head = rxq->elts_head;
 733         struct ibv_sge sges[pkts_n];
 734         unsigned int i;
 735         unsigned int pkts_ret = 0;
 736         int ret;
 737
 738         if (unlikely(rxq->sp))
 739                 return mlx5_rx_burst_sp(dpdk_rxq, pkts, pkts_n);
 740         for (i = 0; (i != pkts_n); ++i) {
 741                 struct rxq_elt *elt = &(*elts)[elts_head];
 742                 struct ibv_recv_wr *wr = &elt->wr;
 743                 uint64_t wr_id = wr->wr_id;
 744                 unsigned int len;
 745                 struct rte_mbuf *seg = (void *)((uintptr_t)elt->sge.addr -
 746                         WR_ID(wr_id).offset);
 747                 struct rte_mbuf *rep;
 748                 uint32_t flags;
 749
 750                 /* Sanity checks. */
 751                 assert(WR_ID(wr_id).id < rxq->elts_n);
 752                 assert(wr->sg_list == &elt->sge);
 753                 assert(wr->num_sge == 1);
 754                 assert(elts_head < rxq->elts_n);
 755                 assert(rxq->elts_head < rxq->elts_n);
 756                 /*
 757                  * Fetch initial bytes of packet descriptor into a
 758                  * cacheline while allocating rep.
 759                  */
 760                 rte_prefetch0(seg);
 761                 rte_prefetch0(&seg->cacheline1);
 762                 ret = rxq->if_cq->poll_length_flags(rxq->cq, NULL, NULL,
 763                                                     &flags);
 764                 if (unlikely(ret < 0)) {
 765                         struct ibv_wc wc;
 766                         int wcs_n;
 767
 768                         DEBUG("rxq=%p, poll_length() failed (ret=%d)",
 769                               (void *)rxq, ret);
 770                         /* ibv_poll_cq() must be used in case of failure. */
 771                         wcs_n = ibv_poll_cq(rxq->cq, 1, &wc);
 772                         if (unlikely(wcs_n == 0))
 773                                 break;
 774                         if (unlikely(wcs_n < 0)) {
 775                                 DEBUG("rxq=%p, ibv_poll_cq() failed (wcs_n=%d)",
 776                                       (void *)rxq, wcs_n);
 777                                 break;
 778                         }
 779                         assert(wcs_n == 1);
 780                         if (unlikely(wc.status != IBV_WC_SUCCESS)) {
 781                                 /* Whatever, just repost the offending WR. */
 782                                 DEBUG("rxq=%p, wr_id=%" PRIu64 ": bad work"
 783                                       " completion status (%d): %s",
 784                                       (void *)rxq, wc.wr_id, wc.status,
 785                                       ibv_wc_status_str(wc.status));
 786 #ifdef MLX5_PMD_SOFT_COUNTERS
 787                                 /* Increment dropped packets counter. */
 788                                 ++rxq->stats.idropped;
 789 #endif
 790                                 /* Add SGE to array for repost. */
 791                                 sges[i] = elt->sge;
 792                                 goto repost;
 793                         }
 794                         ret = wc.byte_len;
 795                 }
 796                 if (ret == 0)
 797                         break;
 798                 len = ret;
 799                 rep = __rte_mbuf_raw_alloc(rxq->mp);
 800                 if (unlikely(rep == NULL)) {
 801                         /*
 802                          * Unable to allocate a replacement mbuf,
 803                          * repost WR.
 804                          */
 805                         DEBUG("rxq=%p, wr_id=%" PRIu32 ":"
 806                               " can't allocate a new mbuf",
 807                               (void *)rxq, WR_ID(wr_id).id);
 808                         /* Increment out of memory counters. */
 809                         ++rxq->stats.rx_nombuf;
 810                         ++rxq->priv->dev->data->rx_mbuf_alloc_failed;
 811                         goto repost;
 812                 }
 813
 814                 /* Reconfigure sge to use rep instead of seg. */
 815                 elt->sge.addr = (uintptr_t)rep->buf_addr + RTE_PKTMBUF_HEADROOM;
 816                 assert(elt->sge.lkey == rxq->mr->lkey);
 817                 WR_ID(wr->wr_id).offset =
 818                         (((uintptr_t)rep->buf_addr + RTE_PKTMBUF_HEADROOM) -
 819                          (uintptr_t)rep);
 820                 assert(WR_ID(wr->wr_id).id == WR_ID(wr_id).id);
 821
 822                 /* Add SGE to array for repost. */
 823                 sges[i] = elt->sge;
 824
 825                 /* Update seg information. */
 826                 SET_DATA_OFF(seg, RTE_PKTMBUF_HEADROOM);
 827                 NB_SEGS(seg) = 1;
 828                 PORT(seg) = rxq->port_id;
 829                 NEXT(seg) = NULL;
 830                 PKT_LEN(seg) = len;
 831                 DATA_LEN(seg) = len;
 832
 833                 /* Return packet. */
 834                 *(pkts++) = seg;
 835                 ++pkts_ret;
 836 #ifdef MLX5_PMD_SOFT_COUNTERS
 837                 /* Increment bytes counter. */
 838                 rxq->stats.ibytes += len;
 839 #endif
 840 repost:
 841                 if (++elts_head >= elts_n)
 842                         elts_head = 0;
 843                 continue;
 844         }
 845         if (unlikely(i == 0))
 846                 return 0;
 847         /* Repost WRs. */
 848 #ifdef DEBUG_RECV
 849         DEBUG("%p: reposting %u WRs", (void *)rxq, i);
 850 #endif
 851         ret = rxq->if_qp->recv_burst(rxq->qp, sges, i);
 852         if (unlikely(ret)) {
 853                 /* Inability to repost WRs is fatal. */
 854                 DEBUG("%p: recv_burst(): failed (ret=%d)",
 855                       (void *)rxq->priv,
 856                       ret);
 857                 abort();
 858         }
 859         rxq->elts_head = elts_head;
 860 #ifdef MLX5_PMD_SOFT_COUNTERS
 861         /* Increment packets counter. */
 862         rxq->stats.ipackets += pkts_ret;
 863 #endif
 864         return pkts_ret;
 865 }
 866
 867 /**
 868  * Dummy DPDK callback for TX.
 869  *
 870  * This function is used to temporarily replace the real callback during
 871  * unsafe control operations on the queue, or in case of error.
 872  *
 873  * @param dpdk_txq
 874  *   Generic pointer to TX queue structure.
 875  * @param[in] pkts
 876  *   Packets to transmit.
 877  * @param pkts_n
 878  *   Number of packets in array.
 879  *
 880  * @return
 881  *   Number of packets successfully transmitted (<= pkts_n).
 882  */
 883 uint16_t
 884 removed_tx_burst(void *dpdk_txq, struct rte_mbuf **pkts, uint16_t pkts_n)
 885 {
 886         (void)dpdk_txq;
 887         (void)pkts;
 888         (void)pkts_n;
 889         return 0;
 890 }
 891
 892 /**
 893  * Dummy DPDK callback for RX.
 894  *
 895  * This function is used to temporarily replace the real callback during
 896  * unsafe control operations on the queue, or in case of error.
 897  *
 898  * @param dpdk_rxq
 899  *   Generic pointer to RX queue structure.
 900  * @param[out] pkts
 901  *   Array to store received packets.
 902  * @param pkts_n
 903  *   Maximum number of packets in array.
 904  *
 905  * @return
 906  *   Number of packets successfully received (<= pkts_n).
 907  */
 908 uint16_t
 909 removed_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 910 {
 911         (void)dpdk_rxq;
 912         (void)pkts;
 913         (void)pkts_n;
 914         return 0;
 915 }