static int xenvif_gop_skb(struct sk_buff *skb,
			  struct netrx_pending_operations *npo)
{
	struct xenvif *vif = netdev_priv(skb->dev);
	int nr_frags = skb_shinfo(skb)->nr_frags;
	int i;
	struct xen_netif_rx_request *req;
	struct xenvif_rx_meta *meta;
	unsigned char *data;
	int head = 1;
	int old_meta_prod;
	int gso_type;
	struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg;
	grant_ref_t foreign_grefs[MAX_SKB_FRAGS];
	struct xenvif *foreign_vif = NULL;

	old_meta_prod = npo->meta_prod;

	gso_type = XEN_NETIF_GSO_TYPE_NONE;
	if (skb_is_gso(skb)) {
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
			gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
			gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
	}

	/* Set up a GSO prefix descriptor, if necessary */
	if ((1 << gso_type) & vif->gso_prefix_mask) {
		req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
		meta = npo->meta + npo->meta_prod++;
		meta->gso_type = gso_type;
		meta->gso_size = skb_shinfo(skb)->gso_size;
		meta->size = 0;
		meta->id = req->id;
	}

	req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
	meta = npo->meta + npo->meta_prod++;

	if ((1 << gso_type) & vif->gso_mask) {
		meta->gso_type = gso_type;
		meta->gso_size = skb_shinfo(skb)->gso_size;
	} else {
		meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
		meta->gso_size = 0;
	}

	meta->size = 0;
	meta->id = req->id;
	npo->copy_off = 0;
	npo->copy_gref = req->gref;

	if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) &&
		 (ubuf->callback == &xenvif_zerocopy_callback)) {
		int i = 0;
		foreign_vif = ubuf_to_vif(ubuf);

		do {
			u16 pending_idx = ubuf->desc;
			foreign_grefs[i++] =
				foreign_vif->pending_tx_info[pending_idx].req.gref;
			ubuf = (struct ubuf_info *) ubuf->ctx;
		} while (ubuf);
	}

	data = skb->data;
	while (data < skb_tail_pointer(skb)) {
		unsigned int offset = offset_in_page(data);
		unsigned int len = PAGE_SIZE - offset;

		if (data + len > skb_tail_pointer(skb))
			len = skb_tail_pointer(skb) - data;

		xenvif_gop_frag_copy(vif, skb, npo,
				     virt_to_page(data), len, offset, &head,
				     NULL,
				     0);
		data += len;
	}

	for (i = 0; i < nr_frags; i++) {
		xenvif_gop_frag_copy(vif, skb, npo,
				     skb_frag_page(&skb_shinfo(skb)->frags[i]),
				     skb_frag_size(&skb_shinfo(skb)->frags[i]),
				     skb_shinfo(skb)->frags[i].page_offset,
				     &head,
				     foreign_vif,
				     foreign_grefs[i]);
	}

	return npo->meta_prod - old_meta_prod;
}
static int xenvif_gop_skb(struct sk_buff *skb,
			  struct netrx_pending_operations *npo)
{
	struct xenvif *vif = netdev_priv(skb->dev);
	int nr_frags = skb_shinfo(skb)->nr_frags;
	int i;
	struct xen_netif_rx_request *req;
	struct xenvif_rx_meta *meta;
	unsigned char *data;
	int head = 1;
	int old_meta_prod;
	int gso_type;
	struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg;
	grant_ref_t foreign_grefs[MAX_SKB_FRAGS];
	struct xenvif *foreign_vif = NULL;

	old_meta_prod = npo->meta_prod;

	gso_type = XEN_NETIF_GSO_TYPE_NONE;
	if (skb_is_gso(skb)) {
		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
			gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
		else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
			gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
	}

	 
	if ((1 << gso_type) & vif->gso_prefix_mask) {
		req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
		meta = npo->meta + npo->meta_prod++;
		meta->gso_type = gso_type;
		meta->gso_size = skb_shinfo(skb)->gso_size;
		meta->size = 0;
		meta->id = req->id;
	}

	req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
	meta = npo->meta + npo->meta_prod++;

	if ((1 << gso_type) & vif->gso_mask) {
		meta->gso_type = gso_type;
		meta->gso_size = skb_shinfo(skb)->gso_size;
	} else {
		meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
		meta->gso_size = 0;
	}

	meta->size = 0;
	meta->id = req->id;
	npo->copy_off = 0;
	npo->copy_gref = req->gref;

	if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) &&
		 (ubuf->callback == &xenvif_zerocopy_callback)) {
		int i = 0;
		foreign_vif = ubuf_to_vif(ubuf);

		do {
			u16 pending_idx = ubuf->desc;
			foreign_grefs[i++] =
				foreign_vif->pending_tx_info[pending_idx].req.gref;
			ubuf = (struct ubuf_info *) ubuf->ctx;
		} while (ubuf);
	}

	data = skb->data;
	while (data < skb_tail_pointer(skb)) {
		unsigned int offset = offset_in_page(data);
		unsigned int len = PAGE_SIZE - offset;

		if (data + len > skb_tail_pointer(skb))
			len = skb_tail_pointer(skb) - data;

		xenvif_gop_frag_copy(vif, skb, npo,
				     virt_to_page(data), len, offset, &head,
				     NULL,
				     0);
		data += len;
	}

	for (i = 0; i < nr_frags; i++) {
		xenvif_gop_frag_copy(vif, skb, npo,
				     skb_frag_page(&skb_shinfo(skb)->frags[i]),
				     skb_frag_size(&skb_shinfo(skb)->frags[i]),
				     skb_shinfo(skb)->frags[i].page_offset,
				     &head,
				     foreign_vif,
				     foreign_grefs[i]);
	}

	return npo->meta_prod - old_meta_prod;
}