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, struct rte_mbuf **rx_pkts,
  40         uint16_t nb_pkts)
  41 {
  42         struct virtnet_rx *rxvq = rx_queue;
  43         struct virtqueue *vq = rxvq->vq;
  44         struct virtio_hw *hw = vq->hw;
  45         uint16_t nb_used, nb_total;
  46         uint16_t desc_idx;
  47         struct vring_used_elem *rused;
  48         struct rte_mbuf **sw_ring;
  49         struct rte_mbuf **sw_ring_end;
  50         struct rte_mbuf **ref_rx_pkts;
  51         uint16_t nb_pkts_received = 0;
  52
  53         uint8x16_t shuf_msk1 = {
  54                 0xFF, 0xFF, 0xFF, 0xFF, /* packet type */
  55                 4, 5, 0xFF, 0xFF,       /* pkt len */
  56                 4, 5,                   /* dat len */
  57                 0xFF, 0xFF,             /* vlan tci */
  58                 0xFF, 0xFF, 0xFF, 0xFF
  59         };
  60
  61         uint8x16_t shuf_msk2 = {
  62                 0xFF, 0xFF, 0xFF, 0xFF, /* packet type */
  63                 12, 13, 0xFF, 0xFF,     /* pkt len */
  64                 12, 13,                 /* dat len */
  65                 0xFF, 0xFF,             /* vlan tci */
  66                 0xFF, 0xFF, 0xFF, 0xFF
  67         };
  68
  69         /* Subtract the header length.
  70          *  In which case do we need the header length in used->len ?
  71          */
  72         uint16x8_t len_adjust = {
  73                 0, 0,
  74                 (uint16_t)vq->hw->vtnet_hdr_size, 0,
  75                 (uint16_t)vq->hw->vtnet_hdr_size,
  76                 0,
  77                 0, 0
  78         };
  79
  80         if (unlikely(hw->started == 0))
  81                 return nb_pkts_received;
  82
  83         if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
  84                 return 0;
  85
  86         /* virtqueue_nused has a load-acquire or rte_cio_rmb inside */
  87         nb_used = virtqueue_nused(vq);
  88
  89         if (unlikely(nb_used == 0))
  90                 return 0;
  91
  92         nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
  93         nb_used = RTE_MIN(nb_used, nb_pkts);
  94
  95         desc_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
  96         rused = &vq->vq_split.ring.used->ring[desc_idx];
  97         sw_ring  = &vq->sw_ring[desc_idx];
  98         sw_ring_end = &vq->sw_ring[vq->vq_nentries];
  99
 100         rte_prefetch_non_temporal(rused);
 101
 102         if (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
 103                 virtio_rxq_rearm_vec(rxvq);
 104                 if (unlikely(virtqueue_kick_prepare(vq)))
 105                         virtqueue_notify(vq);
 106         }
 107
 108         nb_total = nb_used;
 109         ref_rx_pkts = rx_pkts;
 110         for (nb_pkts_received = 0;
 111                 nb_pkts_received < nb_total;) {
 112                 uint64x2_t desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
 113                 uint64x2_t mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
 114                 uint64x2_t pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
 115
 116                 mbp[0] = vld1q_u64((uint64_t *)(sw_ring + 0));
 117                 desc[0] = vld1q_u64((uint64_t *)(rused + 0));
 118                 vst1q_u64((uint64_t *)&rx_pkts[0], mbp[0]);
 119
 120                 mbp[1] = vld1q_u64((uint64_t *)(sw_ring + 2));
 121                 desc[1] = vld1q_u64((uint64_t *)(rused + 2));
 122                 vst1q_u64((uint64_t *)&rx_pkts[2], mbp[1]);
 123
 124                 mbp[2] = vld1q_u64((uint64_t *)(sw_ring + 4));
 125                 desc[2] = vld1q_u64((uint64_t *)(rused + 4));
 126                 vst1q_u64((uint64_t *)&rx_pkts[4], mbp[2]);
 127
 128                 mbp[3] = vld1q_u64((uint64_t *)(sw_ring + 6));
 129                 desc[3] = vld1q_u64((uint64_t *)(rused + 6));
 130                 vst1q_u64((uint64_t *)&rx_pkts[6], mbp[3]);
 131
 132                 pkt_mb[1] = vreinterpretq_u64_u8(vqtbl1q_u8(
 133                                 vreinterpretq_u8_u64(desc[0]), shuf_msk2));
 134                 pkt_mb[0] = vreinterpretq_u64_u8(vqtbl1q_u8(
 135                                 vreinterpretq_u8_u64(desc[0]), shuf_msk1));
 136                 pkt_mb[1] = vreinterpretq_u64_u16(vsubq_u16(
 137                                 vreinterpretq_u16_u64(pkt_mb[1]), len_adjust));
 138                 pkt_mb[0] = vreinterpretq_u64_u16(vsubq_u16(
 139                                 vreinterpretq_u16_u64(pkt_mb[0]), len_adjust));
 140                 vst1q_u64((void *)&rx_pkts[1]->rx_descriptor_fields1,
 141                         pkt_mb[1]);
 142                 vst1q_u64((void *)&rx_pkts[0]->rx_descriptor_fields1,
 143                         pkt_mb[0]);
 144
 145                 pkt_mb[3] = vreinterpretq_u64_u8(vqtbl1q_u8(
 146                                 vreinterpretq_u8_u64(desc[1]), shuf_msk2));
 147                 pkt_mb[2] = vreinterpretq_u64_u8(vqtbl1q_u8(
 148                                 vreinterpretq_u8_u64(desc[1]), shuf_msk1));
 149                 pkt_mb[3] = vreinterpretq_u64_u16(vsubq_u16(
 150                                 vreinterpretq_u16_u64(pkt_mb[3]), len_adjust));
 151                 pkt_mb[2] = vreinterpretq_u64_u16(vsubq_u16(
 152                                 vreinterpretq_u16_u64(pkt_mb[2]), len_adjust));
 153                 vst1q_u64((void *)&rx_pkts[3]->rx_descriptor_fields1,
 154                         pkt_mb[3]);
 155                 vst1q_u64((void *)&rx_pkts[2]->rx_descriptor_fields1,
 156                         pkt_mb[2]);
 157
 158                 pkt_mb[5] = vreinterpretq_u64_u8(vqtbl1q_u8(
 159                                 vreinterpretq_u8_u64(desc[2]), shuf_msk2));
 160                 pkt_mb[4] = vreinterpretq_u64_u8(vqtbl1q_u8(
 161                                 vreinterpretq_u8_u64(desc[2]), shuf_msk1));
 162                 pkt_mb[5] = vreinterpretq_u64_u16(vsubq_u16(
 163                                 vreinterpretq_u16_u64(pkt_mb[5]), len_adjust));
 164                 pkt_mb[4] = vreinterpretq_u64_u16(vsubq_u16(
 165                                 vreinterpretq_u16_u64(pkt_mb[4]), len_adjust));
 166                 vst1q_u64((void *)&rx_pkts[5]->rx_descriptor_fields1,
 167                         pkt_mb[5]);
 168                 vst1q_u64((void *)&rx_pkts[4]->rx_descriptor_fields1,
 169                         pkt_mb[4]);
 170
 171                 pkt_mb[7] = vreinterpretq_u64_u8(vqtbl1q_u8(
 172                                 vreinterpretq_u8_u64(desc[3]), shuf_msk2));
 173                 pkt_mb[6] = vreinterpretq_u64_u8(vqtbl1q_u8(
 174                                 vreinterpretq_u8_u64(desc[3]), shuf_msk1));
 175                 pkt_mb[7] = vreinterpretq_u64_u16(vsubq_u16(
 176                                 vreinterpretq_u16_u64(pkt_mb[7]), len_adjust));
 177                 pkt_mb[6] = vreinterpretq_u64_u16(vsubq_u16(
 178                                 vreinterpretq_u16_u64(pkt_mb[6]), len_adjust));
 179                 vst1q_u64((void *)&rx_pkts[7]->rx_descriptor_fields1,
 180                         pkt_mb[7]);
 181                 vst1q_u64((void *)&rx_pkts[6]->rx_descriptor_fields1,
 182                         pkt_mb[6]);
 183
 184                 if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
 185                         if (sw_ring + nb_used <= sw_ring_end)
 186                                 nb_pkts_received += nb_used;
 187                         else
 188                                 nb_pkts_received += sw_ring_end - sw_ring;
 189                         break;
 190                 } else {
 191                         if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
 192                                 sw_ring_end)) {
 193                                 nb_pkts_received += sw_ring_end - sw_ring;
 194                                 break;
 195                         } else {
 196                                 nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
 197
 198                                 rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
 199                                 sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
 200                                 rused   += RTE_VIRTIO_DESC_PER_LOOP;
 201                                 nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
 202                         }
 203                 }
 204         }
 205
 206         vq->vq_used_cons_idx += nb_pkts_received;
 207         vq->vq_free_cnt += nb_pkts_received;
 208         rxvq->stats.packets += nb_pkts_received;
 209         for (nb_used = 0; nb_used < nb_pkts_received; nb_used++)
 210                 virtio_update_packet_stats(&rxvq->stats, ref_rx_pkts[nb_used]);
 211
 212         return nb_pkts_received;
 213 }