drivers/net/virtio/virtio_rxtx_simple_sse.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   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 Intel Corporation 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 <stdint.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <errno.h>
  39
  40 #include <tmmintrin.h>
  41
  42 #include <rte_byteorder.h>
  43 #include <rte_branch_prediction.h>
  44 #include <rte_cycles.h>
  45 #include <rte_ether.h>
  46 #include <rte_ethdev.h>
  47 #include <rte_errno.h>
  48 #include <rte_memory.h>
  49 #include <rte_mempool.h>
  50 #include <rte_malloc.h>
  51 #include <rte_mbuf.h>
  52 #include <rte_prefetch.h>
  53 #include <rte_string_fns.h>
  54
  55 #include "virtio_rxtx_simple.h"
  56
  57 #define RTE_VIRTIO_VPMD_RX_BURST 32
  58 #define RTE_VIRTIO_DESC_PER_LOOP 8
  59 #define RTE_VIRTIO_VPMD_RX_REARM_THRESH RTE_VIRTIO_VPMD_RX_BURST
  60
  61 /* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
  62  *
  63  * This routine is for non-mergeable RX, one desc for each guest buffer.
  64  * This routine is based on the RX ring layout optimization. Each entry in the
  65  * avail ring points to the desc with the same index in the desc ring and this
  66  * will never be changed in the driver.
  67  *
  68  * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
  69  */
  70 uint16_t
  71 virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
  72         uint16_t nb_pkts)
  73 {
  74         struct virtnet_rx *rxvq = rx_queue;
  75         struct virtqueue *vq = rxvq->vq;
  76         struct virtio_hw *hw = vq->hw;
  77         uint16_t nb_used;
  78         uint16_t desc_idx;
  79         struct vring_used_elem *rused;
  80         struct rte_mbuf **sw_ring;
  81         struct rte_mbuf **sw_ring_end;
  82         uint16_t nb_pkts_received = 0;
  83         __m128i shuf_msk1, shuf_msk2, len_adjust;
  84
  85         shuf_msk1 = _mm_set_epi8(
  86                 0xFF, 0xFF, 0xFF, 0xFF,
  87                 0xFF, 0xFF,             /* vlan tci */
  88                 5, 4,                   /* dat len */
  89                 0xFF, 0xFF, 5, 4,       /* pkt len */
  90                 0xFF, 0xFF, 0xFF, 0xFF  /* packet type */
  91
  92         );
  93
  94         shuf_msk2 = _mm_set_epi8(
  95                 0xFF, 0xFF, 0xFF, 0xFF,
  96                 0xFF, 0xFF,             /* vlan tci */
  97                 13, 12,                 /* dat len */
  98                 0xFF, 0xFF, 13, 12,     /* pkt len */
  99                 0xFF, 0xFF, 0xFF, 0xFF  /* packet type */
 100         );
 101
 102         /* Subtract the header length.
 103         *  In which case do we need the header length in used->len ?
 104         */
 105         len_adjust = _mm_set_epi16(
 106                 0, 0,
 107                 0,
 108                 (uint16_t)-vq->hw->vtnet_hdr_size,
 109                 0, (uint16_t)-vq->hw->vtnet_hdr_size,
 110                 0, 0);
 111
 112         if (unlikely(hw->started == 0))
 113                 return nb_pkts_received;
 114
 115         if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
 116                 return 0;
 117
 118         nb_used = VIRTQUEUE_NUSED(vq);
 119
 120         rte_compiler_barrier();
 121
 122         if (unlikely(nb_used == 0))
 123                 return 0;
 124
 125         nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
 126         nb_used = RTE_MIN(nb_used, nb_pkts);
 127
 128         desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
 129         rused = &vq->vq_ring.used->ring[desc_idx];
 130         sw_ring  = &vq->sw_ring[desc_idx];
 131         sw_ring_end = &vq->sw_ring[vq->vq_nentries];
 132
 133         rte_prefetch0(rused);
 134
 135         if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
 136                 virtio_rxq_rearm_vec(rxvq);
 137                 if (unlikely(virtqueue_kick_prepare(vq)))
 138                         virtqueue_notify(vq);
 139         }
 140
 141         for (nb_pkts_received = 0;
 142                 nb_pkts_received < nb_used;) {
 143                 __m128i desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
 144                 __m128i mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
 145                 __m128i pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
 146
 147                 mbp[0] = _mm_loadu_si128((__m128i *)(sw_ring + 0));
 148                 desc[0] = _mm_loadu_si128((__m128i *)(rused + 0));
 149                 _mm_storeu_si128((__m128i *)&rx_pkts[0], mbp[0]);
 150
 151                 mbp[1] = _mm_loadu_si128((__m128i *)(sw_ring + 2));
 152                 desc[1] = _mm_loadu_si128((__m128i *)(rused + 2));
 153                 _mm_storeu_si128((__m128i *)&rx_pkts[2], mbp[1]);
 154
 155                 mbp[2] = _mm_loadu_si128((__m128i *)(sw_ring + 4));
 156                 desc[2] = _mm_loadu_si128((__m128i *)(rused + 4));
 157                 _mm_storeu_si128((__m128i *)&rx_pkts[4], mbp[2]);
 158
 159                 mbp[3] = _mm_loadu_si128((__m128i *)(sw_ring + 6));
 160                 desc[3] = _mm_loadu_si128((__m128i *)(rused + 6));
 161                 _mm_storeu_si128((__m128i *)&rx_pkts[6], mbp[3]);
 162
 163                 pkt_mb[1] = _mm_shuffle_epi8(desc[0], shuf_msk2);
 164                 pkt_mb[0] = _mm_shuffle_epi8(desc[0], shuf_msk1);
 165                 pkt_mb[1] = _mm_add_epi16(pkt_mb[1], len_adjust);
 166                 pkt_mb[0] = _mm_add_epi16(pkt_mb[0], len_adjust);
 167                 _mm_storeu_si128((void *)&rx_pkts[1]->rx_descriptor_fields1,
 168                         pkt_mb[1]);
 169                 _mm_storeu_si128((void *)&rx_pkts[0]->rx_descriptor_fields1,
 170                         pkt_mb[0]);
 171
 172                 pkt_mb[3] = _mm_shuffle_epi8(desc[1], shuf_msk2);
 173                 pkt_mb[2] = _mm_shuffle_epi8(desc[1], shuf_msk1);
 174                 pkt_mb[3] = _mm_add_epi16(pkt_mb[3], len_adjust);
 175                 pkt_mb[2] = _mm_add_epi16(pkt_mb[2], len_adjust);
 176                 _mm_storeu_si128((void *)&rx_pkts[3]->rx_descriptor_fields1,
 177                         pkt_mb[3]);
 178                 _mm_storeu_si128((void *)&rx_pkts[2]->rx_descriptor_fields1,
 179                         pkt_mb[2]);
 180
 181                 pkt_mb[5] = _mm_shuffle_epi8(desc[2], shuf_msk2);
 182                 pkt_mb[4] = _mm_shuffle_epi8(desc[2], shuf_msk1);
 183                 pkt_mb[5] = _mm_add_epi16(pkt_mb[5], len_adjust);
 184                 pkt_mb[4] = _mm_add_epi16(pkt_mb[4], len_adjust);
 185                 _mm_storeu_si128((void *)&rx_pkts[5]->rx_descriptor_fields1,
 186                         pkt_mb[5]);
 187                 _mm_storeu_si128((void *)&rx_pkts[4]->rx_descriptor_fields1,
 188                         pkt_mb[4]);
 189
 190                 pkt_mb[7] = _mm_shuffle_epi8(desc[3], shuf_msk2);
 191                 pkt_mb[6] = _mm_shuffle_epi8(desc[3], shuf_msk1);
 192                 pkt_mb[7] = _mm_add_epi16(pkt_mb[7], len_adjust);
 193                 pkt_mb[6] = _mm_add_epi16(pkt_mb[6], len_adjust);
 194                 _mm_storeu_si128((void *)&rx_pkts[7]->rx_descriptor_fields1,
 195                         pkt_mb[7]);
 196                 _mm_storeu_si128((void *)&rx_pkts[6]->rx_descriptor_fields1,
 197                         pkt_mb[6]);
 198
 199                 if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
 200                         if (sw_ring + nb_used <= sw_ring_end)
 201                                 nb_pkts_received += nb_used;
 202                         else
 203                                 nb_pkts_received += sw_ring_end - sw_ring;
 204                         break;
 205                 } else {
 206                         if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
 207                                 sw_ring_end)) {
 208                                 nb_pkts_received += sw_ring_end - sw_ring;
 209                                 break;
 210                         } else {
 211                                 nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
 212
 213                                 rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
 214                                 sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
 215                                 rused   += RTE_VIRTIO_DESC_PER_LOOP;
 216                                 nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
 217                         }
 218                 }
 219         }
 220
 221         vq->vq_used_cons_idx += nb_pkts_received;
 222         vq->vq_free_cnt += nb_pkts_received;
 223         rxvq->stats.packets += nb_pkts_received;
 224         return nb_pkts_received;
 225 }