1 files changed, 15 insertions, 19 deletions

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index e481f3710bd3..1049c34e7d43 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -258,18 +258,18 @@ static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
                                                  struct netrx_pending_operations *npo)
 {
         struct xenvif_rx_meta *meta;
-        struct xen_netif_rx_request *req;
+        struct xen_netif_rx_request req;
 
-        req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+        RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
 
         meta = npo->meta + npo->meta_prod++;
         meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
         meta->gso_size = 0;
         meta->size = 0;
-        meta->id = req->id;
+        meta->id = req.id;
 
         npo->copy_off = 0;
-        npo->copy_gref = req->gref;
+        npo->copy_gref = req.gref;
 
         return meta;
 }
@@ -424,7 +424,7 @@ static int xenvif_gop_skb(struct sk_buff *skb,
         struct xenvif *vif = netdev_priv(skb->dev);
         int nr_frags = skb_shinfo(skb)->nr_frags;
         int i;
-        struct xen_netif_rx_request *req;
+        struct xen_netif_rx_request req;
         struct xenvif_rx_meta *meta;
         unsigned char *data;
         int head = 1;
@@ -443,15 +443,15 @@ static int xenvif_gop_skb(struct sk_buff *skb,
 
         /* Set up a GSO prefix descriptor, if necessary */
         if ((1 << gso_type) & vif->gso_prefix_mask) {
-                req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+                RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
                 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;
+                meta->id = req.id;
         }
 
-        req = RING_GET_REQUEST(&queue->rx, queue->rx.req_cons++);
+        RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
         meta = npo->meta + npo->meta_prod++;
 
         if ((1 << gso_type) & vif->gso_mask) {
@@ -463,9 +463,9 @@ static int xenvif_gop_skb(struct sk_buff *skb,
         }
 
         meta->size = 0;
-        meta->id = req->id;
+        meta->id = req.id;
         npo->copy_off = 0;
-        npo->copy_gref = req->gref;
+        npo->copy_gref = req.gref;
 
         data = skb->data;
         while (data < skb_tail_pointer(skb)) {
@@ -679,9 +679,7 @@ static void tx_add_credit(struct xenvif_queue *queue)
          * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
          * Otherwise the interface can seize up due to insufficient credit.
          */
-        max_burst = RING_GET_REQUEST(&queue->tx, queue->tx.req_cons)->size;
-        max_burst = min(max_burst, 131072UL);
-        max_burst = max(max_burst, queue->credit_bytes);
+        max_burst = max(131072UL, queue->credit_bytes);
 
         /* Take care that adding a new chunk of credit doesn't wrap to zero. */
         max_credit = queue->remaining_credit + queue->credit_bytes;
@@ -711,7 +709,7 @@ static void xenvif_tx_err(struct xenvif_queue *queue,
                 spin_unlock_irqrestore(&queue->response_lock, flags);
                 if (cons == end)
                         break;
-                txp = RING_GET_REQUEST(&queue->tx, cons++);
+                RING_COPY_REQUEST(&queue->tx, cons++, txp);
         } while (1);
         queue->tx.req_cons = cons;
 }
@@ -778,8 +776,7 @@ static int xenvif_count_requests(struct xenvif_queue *queue,
                 if (drop_err)
                         txp = &dropped_tx;
 
-                memcpy(txp, RING_GET_REQUEST(&queue->tx, cons + slots),
-                       sizeof(*txp));
+                RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
 
                 /* If the guest submitted a frame >= 64 KiB then
                  * first->size overflowed and following slots will
@@ -1112,8 +1109,7 @@ static int xenvif_get_extras(struct xenvif_queue *queue,
                         return -EBADR;
                 }
 
-                memcpy(&extra, RING_GET_REQUEST(&queue->tx, cons),
-                       sizeof(extra));
+                RING_COPY_REQUEST(&queue->tx, cons, &extra);
                 if (unlikely(!extra.type ||
                              extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
                         queue->tx.req_cons = ++cons;
@@ -1322,7 +1318,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue,
 
                 idx = queue->tx.req_cons;
                 rmb(); /* Ensure that we see the request before we copy it. */
-                memcpy(&txreq, RING_GET_REQUEST(&queue->tx, idx), sizeof(txreq));
+                RING_COPY_REQUEST(&queue->tx, idx, &txreq);
 
                 /* Credit-based scheduling. */
                 if (txreq.size > queue->remaining_credit &&