drivers/net/virtio/virtio_rxtx_simple.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2015 Intel Corporation
   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_cycles.h>
  12 #include <rte_memory.h>
  13 #include <rte_branch_prediction.h>
  14 #include <rte_mempool.h>
  15 #include <rte_malloc.h>
  16 #include <rte_mbuf.h>
  17 #include <rte_ether.h>
  18 #include <rte_ethdev_driver.h>
  19 #include <rte_prefetch.h>
  20 #include <rte_string_fns.h>
  21 #include <rte_errno.h>
  22 #include <rte_byteorder.h>
  23
  24 #include "virtio_rxtx_simple.h"
  25
  26 #ifndef __INTEL_COMPILER
  27 #pragma GCC diagnostic ignored "-Wcast-qual"
  28 #endif
  29
  30 int __attribute__((cold))
  31 virtqueue_enqueue_recv_refill_simple(struct virtqueue *vq,
  32         struct rte_mbuf *cookie)
  33 {
  34         struct vq_desc_extra *dxp;
  35         struct vring_desc *start_dp;
  36         uint16_t desc_idx;
  37
  38         cookie->port = vq->rxq.port_id;
  39
  40         desc_idx = vq->vq_avail_idx & (vq->vq_nentries - 1);
  41         dxp = &vq->vq_descx[desc_idx];
  42         dxp->cookie = (void *)cookie;
  43         vq->sw_ring[desc_idx] = cookie;
  44
  45         start_dp = vq->vq_ring.desc;
  46         start_dp[desc_idx].addr =
  47                 VIRTIO_MBUF_ADDR(cookie, vq) +
  48                 RTE_PKTMBUF_HEADROOM - vq->hw->vtnet_hdr_size;
  49         start_dp[desc_idx].len = cookie->buf_len -
  50                 RTE_PKTMBUF_HEADROOM + vq->hw->vtnet_hdr_size;
  51
  52         vq->vq_free_cnt--;
  53         vq->vq_avail_idx++;
  54
  55         return 0;
  56 }
  57
  58 uint16_t
  59 virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
  60         uint16_t nb_pkts)
  61 {
  62         struct virtnet_tx *txvq = tx_queue;
  63         struct virtqueue *vq = txvq->vq;
  64         struct virtio_hw *hw = vq->hw;
  65         uint16_t nb_used;
  66         uint16_t desc_idx;
  67         struct vring_desc *start_dp;
  68         uint16_t nb_tail, nb_commit;
  69         int i;
  70         uint16_t desc_idx_max = (vq->vq_nentries >> 1) - 1;
  71         uint16_t nb_tx = 0;
  72
  73         if (unlikely(hw->started == 0 && tx_pkts != hw->inject_pkts))
  74                 return nb_tx;
  75
  76         nb_used = VIRTQUEUE_NUSED(vq);
  77         rte_compiler_barrier();
  78
  79         if (nb_used >= VIRTIO_TX_FREE_THRESH)
  80                 virtio_xmit_cleanup(vq);
  81
  82         nb_commit = nb_pkts = RTE_MIN((vq->vq_free_cnt >> 1), nb_pkts);
  83         desc_idx = (uint16_t)(vq->vq_avail_idx & desc_idx_max);
  84         start_dp = vq->vq_ring.desc;
  85         nb_tail = (uint16_t) (desc_idx_max + 1 - desc_idx);
  86
  87         if (nb_commit >= nb_tail) {
  88                 for (i = 0; i < nb_tail; i++)
  89                         vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
  90                 for (i = 0; i < nb_tail; i++) {
  91                         start_dp[desc_idx].addr =
  92                                 VIRTIO_MBUF_DATA_DMA_ADDR(*tx_pkts, vq);
  93                         start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
  94                         tx_pkts++;
  95                         desc_idx++;
  96                 }
  97                 nb_commit -= nb_tail;
  98                 desc_idx = 0;
  99         }
 100         for (i = 0; i < nb_commit; i++)
 101                 vq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
 102         for (i = 0; i < nb_commit; i++) {
 103                 start_dp[desc_idx].addr =
 104                         VIRTIO_MBUF_DATA_DMA_ADDR(*tx_pkts, vq);
 105                 start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
 106                 tx_pkts++;
 107                 desc_idx++;
 108         }
 109
 110         rte_compiler_barrier();
 111
 112         vq->vq_free_cnt -= (uint16_t)(nb_pkts << 1);
 113         vq->vq_avail_idx += nb_pkts;
 114         vq->vq_ring.avail->idx = vq->vq_avail_idx;
 115         txvq->stats.packets += nb_pkts;
 116
 117         if (likely(nb_pkts)) {
 118                 if (unlikely(virtqueue_kick_prepare(vq)))
 119                         virtqueue_notify(vq);
 120         }
 121
 122         return nb_pkts;
 123 }
 124
 125 int __attribute__((cold))
 126 virtio_rxq_vec_setup(struct virtnet_rx *rxq)
 127 {
 128         uintptr_t p;
 129         struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
 130
 131         mb_def.nb_segs = 1;
 132         mb_def.data_off = RTE_PKTMBUF_HEADROOM;
 133         mb_def.port = rxq->port_id;
 134         rte_mbuf_refcnt_set(&mb_def, 1);
 135
 136         /* prevent compiler reordering: rearm_data covers previous fields */
 137         rte_compiler_barrier();
 138         p = (uintptr_t)&mb_def.rearm_data;
 139         rxq->mbuf_initializer = *(uint64_t *)p;
 140
 141         return 0;
 142 }
 143
 144 /* Stub for linkage when arch specific implementation is not available */
 145 uint16_t __attribute__((weak))
 146 virtio_recv_pkts_vec(void *rx_queue __rte_unused,
 147                      struct rte_mbuf **rx_pkts __rte_unused,
 148                      uint16_t nb_pkts __rte_unused)
 149 {
 150         rte_panic("Wrong weak function linked by linker\n");
 151         return 0;
 152 }