+static inline void
+virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
+ uint16_t needed, int can_push)
+{
+ struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
+ struct vq_desc_extra *dxp;
+ struct virtqueue *vq = txvq->vq;
+ struct vring_packed_desc *start_dp, *head_dp;
+ uint16_t idx, id, head_idx, head_flags;
+ uint16_t head_size = vq->hw->vtnet_hdr_size;
+ struct virtio_net_hdr *hdr;
+ uint16_t prev;
+
+ id = vq->vq_desc_head_idx;
+
+ dxp = &vq->vq_descx[id];
+ dxp->ndescs = needed;
+ dxp->cookie = cookie;
+
+ head_idx = vq->vq_avail_idx;
+ idx = head_idx;
+ prev = head_idx;
+ start_dp = vq->ring_packed.desc_packed;
+
+ head_dp = &vq->ring_packed.desc_packed[idx];
+ head_flags = cookie->next ? VRING_DESC_F_NEXT : 0;
+ head_flags |= vq->avail_used_flags;
+
+ if (can_push) {
+ /* prepend cannot fail, checked by caller */
+ hdr = (struct virtio_net_hdr *)
+ rte_pktmbuf_prepend(cookie, head_size);
+ /* rte_pktmbuf_prepend() counts the hdr size to the pkt length,
+ * which is wrong. Below subtract restores correct pkt size.
+ */
+ cookie->pkt_len -= head_size;
+
+ /* if offload disabled, it is not zeroed below, do it now */
+ if (!vq->hw->has_tx_offload) {
+ ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
+ ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
+ }
+ } else {
+ /* setup first tx ring slot to point to header
+ * stored in reserved region.
+ */
+ start_dp[idx].addr = txvq->virtio_net_hdr_mem +
+ RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
+ start_dp[idx].len = vq->hw->vtnet_hdr_size;
+ hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
+ idx++;
+ if (idx >= vq->vq_nentries) {
+ idx -= vq->vq_nentries;
+ vq->avail_wrap_counter ^= 1;
+ vq->avail_used_flags =
+ VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
+ VRING_DESC_F_USED(!vq->avail_wrap_counter);
+ }
+ }
+
+ virtqueue_xmit_offload(hdr, cookie, vq->hw->has_tx_offload);
+
+ do {
+ uint16_t flags;
+
+ start_dp[idx].addr = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
+ start_dp[idx].len = cookie->data_len;
+ if (likely(idx != head_idx)) {
+ flags = cookie->next ? VRING_DESC_F_NEXT : 0;
+ flags |= vq->avail_used_flags;
+ start_dp[idx].flags = flags;
+ }
+ prev = idx;
+ idx++;
+ if (idx >= vq->vq_nentries) {
+ idx -= vq->vq_nentries;
+ vq->avail_wrap_counter ^= 1;
+ vq->avail_used_flags =
+ VRING_DESC_F_AVAIL(vq->avail_wrap_counter) |
+ VRING_DESC_F_USED(!vq->avail_wrap_counter);
+ }
+ } while ((cookie = cookie->next) != NULL);
+
+ start_dp[prev].id = id;
+
+ vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
+
+ vq->vq_desc_head_idx = dxp->next;
+ if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
+ vq->vq_desc_tail_idx = VQ_RING_DESC_CHAIN_END;
+
+ vq->vq_avail_idx = idx;
+
+ rte_smp_wmb();
+ head_dp->flags = head_flags;
+}
+