drivers/net/virtio/virtio_rxtx_simple_neon.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2016 Cavium, Inc
   3  */
   4
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <errno.h>
  10
  11 #include <rte_byteorder.h>
  12 #include <rte_branch_prediction.h>
  13 #include <rte_cycles.h>
  14 #include <rte_ether.h>
  15 #include <rte_ethdev_driver.h>
  16 #include <rte_errno.h>
  17 #include <rte_memory.h>
  18 #include <rte_mempool.h>
  19 #include <rte_malloc.h>
  20 #include <rte_mbuf.h>
  21 #include <rte_prefetch.h>
  22 #include <rte_string_fns.h>
  23 #include <rte_vect.h>
  24
  25 #include "virtio_rxtx_simple.h"
  26
  27 #define RTE_VIRTIO_DESC_PER_LOOP 8
  28
  29 /* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
  30  *
  31  * This routine is for non-mergeable RX, one desc for each guest buffer.
  32  * This routine is based on the RX ring layout optimization. Each entry in the
  33  * avail ring points to the desc with the same index in the desc ring and this
  34  * will never be changed in the driver.
  35  *
  36  * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
  37  */
  38 uint16_t
  39 virtio_recv_pkts_vec(void *rx_queue,
  40                 struct rte_mbuf **__rte_restrict rx_pkts,
  41                 uint16_t nb_pkts)
  42 {
  43         struct virtnet_rx *rxvq = rx_queue;
  44         struct virtqueue *vq = rxvq->vq;
  45         struct virtio_hw *hw = vq->hw;
  46         uint16_t nb_used, nb_total;
  47         uint16_t desc_idx;
  48         struct vring_used_elem *rused;
  49         struct rte_mbuf **sw_ring;
  50         struct rte_mbuf **sw_ring_end;
  51         struct rte_mbuf **ref_rx_pkts;
  52         uint16_t nb_pkts_received = 0;
  53
  54         uint8x16_t shuf_msk1 = {
  55                 0xFF, 0xFF, 0xFF, 0xFF, /* packet type */
  56                 4, 5, 0xFF, 0xFF,       /* pkt len */
  57                 4, 5,                   /* dat len */
  58                 0xFF, 0xFF,             /* vlan tci */
  59                 0xFF, 0xFF, 0xFF, 0xFF
  60         };
  61
  62         uint8x16_t shuf_msk2 = {
  63                 0xFF, 0xFF, 0xFF, 0xFF, /* packet type */
  64                 12, 13, 0xFF, 0xFF,     /* pkt len */
  65                 12, 13,                 /* dat len */
  66                 0xFF, 0xFF,             /* vlan tci */
  67                 0xFF, 0xFF, 0xFF, 0xFF
  68         };
  69
  70         /* Subtract the header length.
  71          *  In which case do we need the header length in used->len ?
  72          */
  73         uint16x8_t len_adjust = {
  74                 0, 0,
  75                 (uint16_t)hw->vtnet_hdr_size, 0,
  76                 (uint16_t)hw->vtnet_hdr_size,
  77                 0,
  78                 0, 0
  79         };
  80
  81         if (unlikely(hw->started == 0))
  82                 return nb_pkts_received;
  83
  84         if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
  85                 return 0;
  86
  87         /* virtqueue_nused has a load-acquire or rte_cio_rmb inside */
  88         nb_used = virtqueue_nused(vq);
  89
  90         if (unlikely(nb_used == 0))
  91                 return 0;
  92
  93         nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
  94         nb_used = RTE_MIN(nb_used, nb_pkts);
  95
  96         desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
  97         rused = &vq->vq_split.ring.used->ring[desc_idx];
  98         sw_ring  = &vq->sw_ring[desc_idx];
  99         sw_ring_end = &vq->sw_ring[vq->vq_nentries];
 100
 101         rte_prefetch_non_temporal(rused);
 102
 103         if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
 104                 virtio_rxq_rearm_vec(rxvq);
 105                 if (unlikely(virtqueue_kick_prepare(vq)))
 106                         virtqueue_notify(vq);
 107         }
 108
 109         nb_total = nb_used;
 110         ref_rx_pkts = rx_pkts;
 111         for (nb_pkts_received = 0;
 112                 nb_pkts_received < nb_total;) {
 113                 uint64x2_t desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
 114                 uint64x2_t mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
 115                 uint64x2_t pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
 116
 117                 mbp[0] = vld1q_u64((uint64_t *)(sw_ring + 0));
 118                 desc[0] = vld1q_u64((uint64_t *)(rused + 0));
 119                 vst1q_u64((uint64_t *)&rx_pkts[0], mbp[0]);
 120
 121                 mbp[1] = vld1q_u64((uint64_t *)(sw_ring + 2));
 122                 desc[1] = vld1q_u64((uint64_t *)(rused + 2));
 123                 vst1q_u64((uint64_t *)&rx_pkts[2], mbp[1]);
 124
 125                 mbp[2] = vld1q_u64((uint64_t *)(sw_ring + 4));
 126                 desc[2] = vld1q_u64((uint64_t *)(rused + 4));
 127                 vst1q_u64((uint64_t *)&rx_pkts[4], mbp[2]);
 128
 129                 mbp[3] = vld1q_u64((uint64_t *)(sw_ring + 6));
 130                 desc[3] = vld1q_u64((uint64_t *)(rused + 6));
 131                 vst1q_u64((uint64_t *)&rx_pkts[6], mbp[3]);
 132
 133                 pkt_mb[1] = vreinterpretq_u64_u8(vqtbl1q_u8(
 134                                 vreinterpretq_u8_u64(desc[0]), shuf_msk2));
 135                 pkt_mb[0] = vreinterpretq_u64_u8(vqtbl1q_u8(
 136                                 vreinterpretq_u8_u64(desc[0]), shuf_msk1));
 137                 pkt_mb[1] = vreinterpretq_u64_u16(vsubq_u16(
 138                                 vreinterpretq_u16_u64(pkt_mb[1]), len_adjust));
 139                 pkt_mb[0] = vreinterpretq_u64_u16(vsubq_u16(
 140                                 vreinterpretq_u16_u64(pkt_mb[0]), len_adjust));
 141                 vst1q_u64((void *)&rx_pkts[1]->rx_descriptor_fields1,
 142                         pkt_mb[1]);
 143                 vst1q_u64((void *)&rx_pkts[0]->rx_descriptor_fields1,
 144                         pkt_mb[0]);
 145
 146                 pkt_mb[3] = vreinterpretq_u64_u8(vqtbl1q_u8(
 147                                 vreinterpretq_u8_u64(desc[1]), shuf_msk2));
 148                 pkt_mb[2] = vreinterpretq_u64_u8(vqtbl1q_u8(
 149                                 vreinterpretq_u8_u64(desc[1]), shuf_msk1));
 150                 pkt_mb[3] = vreinterpretq_u64_u16(vsubq_u16(
 151                                 vreinterpretq_u16_u64(pkt_mb[3]), len_adjust));
 152                 pkt_mb[2] = vreinterpretq_u64_u16(vsubq_u16(
 153                                 vreinterpretq_u16_u64(pkt_mb[2]), len_adjust));
 154                 vst1q_u64((void *)&rx_pkts[3]->rx_descriptor_fields1,
 155                         pkt_mb[3]);
 156                 vst1q_u64((void *)&rx_pkts[2]->rx_descriptor_fields1,
 157                         pkt_mb[2]);
 158
 159                 pkt_mb[5] = vreinterpretq_u64_u8(vqtbl1q_u8(
 160                                 vreinterpretq_u8_u64(desc[2]), shuf_msk2));
 161                 pkt_mb[4] = vreinterpretq_u64_u8(vqtbl1q_u8(
 162                                 vreinterpretq_u8_u64(desc[2]), shuf_msk1));
 163                 pkt_mb[5] = vreinterpretq_u64_u16(vsubq_u16(
 164                                 vreinterpretq_u16_u64(pkt_mb[5]), len_adjust));
 165                 pkt_mb[4] = vreinterpretq_u64_u16(vsubq_u16(
 166                                 vreinterpretq_u16_u64(pkt_mb[4]), len_adjust));
 167                 vst1q_u64((void *)&rx_pkts[5]->rx_descriptor_fields1,
 168                         pkt_mb[5]);
 169                 vst1q_u64((void *)&rx_pkts[4]->rx_descriptor_fields1,
 170                         pkt_mb[4]);
 171
 172                 pkt_mb[7] = vreinterpretq_u64_u8(vqtbl1q_u8(
 173                                 vreinterpretq_u8_u64(desc[3]), shuf_msk2));
 174                 pkt_mb[6] = vreinterpretq_u64_u8(vqtbl1q_u8(
 175                                 vreinterpretq_u8_u64(desc[3]), shuf_msk1));
 176                 pkt_mb[7] = vreinterpretq_u64_u16(vsubq_u16(
 177                                 vreinterpretq_u16_u64(pkt_mb[7]), len_adjust));
 178                 pkt_mb[6] = vreinterpretq_u64_u16(vsubq_u16(
 179                                 vreinterpretq_u16_u64(pkt_mb[6]), len_adjust));
 180                 vst1q_u64((void *)&rx_pkts[7]->rx_descriptor_fields1,
 181                         pkt_mb[7]);
 182                 vst1q_u64((void *)&rx_pkts[6]->rx_descriptor_fields1,
 183                         pkt_mb[6]);
 184
 185                 if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
 186                         if (sw_ring + nb_used <= sw_ring_end)
 187                                 nb_pkts_received += nb_used;
 188                         else
 189                                 nb_pkts_received += sw_ring_end - sw_ring;
 190                         break;
 191                 } else {
 192                         if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
 193                                 sw_ring_end)) {
 194                                 nb_pkts_received += sw_ring_end - sw_ring;
 195                                 break;
 196                         } else {
 197                                 nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
 198
 199                                 rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
 200                                 sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
 201                                 rused   += RTE_VIRTIO_DESC_PER_LOOP;
 202                                 nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
 203                         }
 204                 }
 205         }
 206
 207         vq->vq_used_cons_idx += nb_pkts_received;
 208         vq->vq_free_cnt += nb_pkts_received;
 209         rxvq->stats.packets += nb_pkts_received;
 210         for (nb_used = 0; nb_used < nb_pkts_received; nb_used++)
 211                 virtio_update_packet_stats(&rxvq->stats, ref_rx_pkts[nb_used]);
 212
 213         return nb_pkts_received;
 214 }