- start_dp[idx].addr =
- txvq->virtio_net_hdr_mem + idx * head_size;
- start_dp[idx].len = head_size;
- start_dp[idx].flags = VRING_DESC_F_NEXT;
+
+ if (use_indirect) {
+ /* setup tx ring slot to point to indirect
+ * descriptor list stored in reserved region.
+ *
+ * the first slot in indirect ring is already preset
+ * to point to the header in reserved region
+ */
+ struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
+
+ offs = idx * sizeof(struct virtio_tx_region)
+ + offsetof(struct virtio_tx_region, tx_indir);
+
+ start_dp[idx].addr = txvq->virtio_net_hdr_mem + offs;
+ start_dp[idx].len = (seg_num + 1) * sizeof(struct vring_desc);
+ start_dp[idx].flags = VRING_DESC_F_INDIRECT;
+
+ /* loop below will fill in rest of the indirect elements */
+ start_dp = txr[idx].tx_indir;
+ idx = 0;
+ } else {
+ /* setup first tx ring slot to point to header
+ * stored in reserved region.
+ */
+ offs = idx * sizeof(struct virtio_tx_region)
+ + offsetof(struct virtio_tx_region, tx_hdr);
+
+ start_dp[idx].addr = txvq->virtio_net_hdr_mem + offs;
+ start_dp[idx].len = txvq->hw->vtnet_hdr_size;
+ start_dp[idx].flags = VRING_DESC_F_NEXT;
+ }