drivers/net/virtio/virtqueue.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2015 Intel Corporation
   3  */
   4 #include <stdint.h>
   5
   6 #include <rte_mbuf.h>
   7
   8 #include "virtqueue.h"
   9 #include "virtio_logs.h"
  10 #include "virtio_pci.h"
  11 #include "virtio_rxtx_simple.h"
  12
  13 /*
  14  * Two types of mbuf to be cleaned:
  15  * 1) mbuf that has been consumed by backend but not used by virtio.
  16  * 2) mbuf that hasn't been consued by backend.
  17  */
  18 struct rte_mbuf *
  19 virtqueue_detatch_unused(struct virtqueue *vq)
  20 {
  21         struct rte_mbuf *cookie;
  22         int idx;
  23
  24         if (vq != NULL)
  25                 for (idx = 0; idx < vq->vq_nentries; idx++) {
  26                         cookie = vq->vq_descx[idx].cookie;
  27                         if (cookie != NULL) {
  28                                 vq->vq_descx[idx].cookie = NULL;
  29                                 return cookie;
  30                         }
  31                 }
  32         return NULL;
  33 }
  34
  35 /* Flush the elements in the used ring. */
  36 void
  37 virtqueue_rxvq_flush(struct virtqueue *vq)
  38 {
  39         struct virtnet_rx *rxq = &vq->rxq;
  40         struct virtio_hw *hw = vq->hw;
  41         struct vring_used_elem *uep;
  42         struct vq_desc_extra *dxp;
  43         uint16_t used_idx, desc_idx;
  44         uint16_t nb_used, i;
  45
  46         nb_used = VIRTQUEUE_NUSED(vq);
  47
  48         for (i = 0; i < nb_used; i++) {
  49                 used_idx = vq->vq_used_cons_idx & (vq->vq_nentries - 1);
  50                 uep = &vq->vq_ring.used->ring[used_idx];
  51                 if (hw->use_simple_rx) {
  52                         desc_idx = used_idx;
  53                         rte_pktmbuf_free(vq->sw_ring[desc_idx]);
  54                         vq->vq_free_cnt++;
  55                 } else {
  56                         desc_idx = (uint16_t)uep->id;
  57                         dxp = &vq->vq_descx[desc_idx];
  58                         if (dxp->cookie != NULL) {
  59                                 rte_pktmbuf_free(dxp->cookie);
  60                                 dxp->cookie = NULL;
  61                         }
  62                         vq_ring_free_chain(vq, desc_idx);
  63                 }
  64                 vq->vq_used_cons_idx++;
  65         }
  66
  67         if (hw->use_simple_rx) {
  68                 while (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
  69                         virtio_rxq_rearm_vec(rxq);
  70                         if (virtqueue_kick_prepare(vq))
  71                                 virtqueue_notify(vq);
  72                 }
  73         }
  74 }