[PATCH 3 of 5] xen-netfront: Avoid unaligned accesses to IP header

Jeremy Fitzhardinge
2008-10-15T00:57:35Z

Align ip header to a 16 byte boundary to avoid unaligned
access like other drivers.
Without this patch, xen-netfront doesn't work well on ia64.

[ Jeff, this is the only patch in the series which is in your
territory. -J ]

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
---
drivers/net/xen-netfront.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -239,10 +239,13 @@
*/
batch_target = np->rx_target - (req_prod - np->rx.rsp_cons);
for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) {
- skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD,
+ skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN,
GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!skb))
goto no_skb;
+
+ /* Align ip header to a 16 bytes boundary */
+ skb_reserve(skb, NET_IP_ALIGN);

page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
if (!page) {