static void netbk_add_frag_responses(struct xenvif *vif, int status,
				     struct netbk_rx_meta *meta,
				     int nr_meta_slots)
{
	int i;
	unsigned long offset;

	/* No fragments used */
	if (nr_meta_slots <= 1)
		return;

	nr_meta_slots--;

	for (i = 0; i < nr_meta_slots; i++) {
		int flags;
		if (i == nr_meta_slots - 1)
			flags = 0;
		else
			flags = XEN_NETRXF_more_data;

		offset = 0;
		make_rx_response(vif, meta[i].id, status, offset,
				 meta[i].size, flags);
	}
}
Exemple #2
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static void netbk_add_frag_responses(netif_t *netif, int status,
				     struct netbk_rx_meta *meta, int nr_frags)
{
	int i;
	unsigned long offset;

	for (i = 0; i < nr_frags; i++) {
		int id = meta[i].id;
		int flags = (i == nr_frags - 1) ? 0 : NETRXF_more_data;

		if (meta[i].copy)
			offset = 0;
		else
			offset = meta[i].frag.page_offset;
		make_rx_response(netif, id, status, offset,
				 meta[i].frag.size, flags);
	}
}
Exemple #3
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static void xenvif_rx_action(struct xenvif *vif)
{
	s8 status;
	u16 flags;
	struct xen_netif_rx_response *resp;
	struct sk_buff_head rxq;
	struct sk_buff *skb;
	LIST_HEAD(notify);
	int ret;
	unsigned long offset;
	bool need_to_notify = false;

	struct netrx_pending_operations npo = {
		.copy  = vif->grant_copy_op,
		.meta  = vif->meta,
	};

	skb_queue_head_init(&rxq);

	while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
		RING_IDX max_slots_needed;
		RING_IDX old_req_cons;
		RING_IDX ring_slots_used;
		int i;

		/* We need a cheap worse case estimate for the number of
		 * slots we'll use.
		 */

		max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) +
						skb_headlen(skb),
						PAGE_SIZE);
		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
			unsigned int size;
			unsigned int offset;

			size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
			offset = skb_shinfo(skb)->frags[i].page_offset;

			/* For a worse-case estimate we need to factor in
			 * the fragment page offset as this will affect the
			 * number of times xenvif_gop_frag_copy() will
			 * call start_new_rx_buffer().
			 */
			max_slots_needed += DIV_ROUND_UP(offset + size,
							 PAGE_SIZE);
		}

		/* To avoid the estimate becoming too pessimal for some
		 * frontends that limit posted rx requests, cap the estimate
		 * at MAX_SKB_FRAGS.
		 */
		if (max_slots_needed > MAX_SKB_FRAGS)
			max_slots_needed = MAX_SKB_FRAGS;

		/* We may need one more slot for GSO metadata */
		if (skb_is_gso(skb) &&
		   (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 ||
		    skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
			max_slots_needed++;

		/* If the skb may not fit then bail out now */
		if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) {
			skb_queue_head(&vif->rx_queue, skb);
			need_to_notify = true;
			vif->rx_last_skb_slots = max_slots_needed;
			break;
		} else
			vif->rx_last_skb_slots = 0;

		old_req_cons = vif->rx.req_cons;
		XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo);
		ring_slots_used = vif->rx.req_cons - old_req_cons;

		BUG_ON(ring_slots_used > max_slots_needed);

		__skb_queue_tail(&rxq, skb);
	}

	BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta));

	if (!npo.copy_prod)
		goto done;

	BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
	gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod);

	while ((skb = __skb_dequeue(&rxq)) != NULL) {

		if ((1 << vif->meta[npo.meta_cons].gso_type) &
		    vif->gso_prefix_mask) {
			resp = RING_GET_RESPONSE(&vif->rx,
						 vif->rx.rsp_prod_pvt++);

			resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;

			resp->offset = vif->meta[npo.meta_cons].gso_size;
			resp->id = vif->meta[npo.meta_cons].id;
			resp->status = XENVIF_RX_CB(skb)->meta_slots_used;

			npo.meta_cons++;
			XENVIF_RX_CB(skb)->meta_slots_used--;
		}


		vif->dev->stats.tx_bytes += skb->len;
		vif->dev->stats.tx_packets++;

		status = xenvif_check_gop(vif,
					  XENVIF_RX_CB(skb)->meta_slots_used,
					  &npo);

		if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
			flags = 0;
		else
			flags = XEN_NETRXF_more_data;

		if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
			flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
		else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
			/* remote but checksummed. */
			flags |= XEN_NETRXF_data_validated;

		offset = 0;
		resp = make_rx_response(vif, vif->meta[npo.meta_cons].id,
					status, offset,
					vif->meta[npo.meta_cons].size,
					flags);

		if ((1 << vif->meta[npo.meta_cons].gso_type) &
		    vif->gso_mask) {
			struct xen_netif_extra_info *gso =
				(struct xen_netif_extra_info *)
				RING_GET_RESPONSE(&vif->rx,
						  vif->rx.rsp_prod_pvt++);

			resp->flags |= XEN_NETRXF_extra_info;

			gso->u.gso.type = vif->meta[npo.meta_cons].gso_type;
			gso->u.gso.size = vif->meta[npo.meta_cons].gso_size;
			gso->u.gso.pad = 0;
			gso->u.gso.features = 0;

			gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
			gso->flags = 0;
		}

		xenvif_add_frag_responses(vif, status,
					  vif->meta + npo.meta_cons + 1,
					  XENVIF_RX_CB(skb)->meta_slots_used);

		RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);

		need_to_notify |= !!ret;

		npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
		dev_kfree_skb(skb);
	}

done:
	if (need_to_notify)
		notify_remote_via_irq(vif->rx_irq);
}

void xenvif_check_rx_xenvif(struct xenvif *vif)
{
	int more_to_do;

	RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);

	if (more_to_do)
		napi_schedule(&vif->napi);
}