Hi,
This patch  provides dynamic two buffer-mode and 3 buffer-mode options.
Previously 2 buffer-mode was compilation option. Now with this patch applied
one can load driver in 2 buffer-mode with module-load parameter

ie.
#insmod s2io.ko rx_ring_mode=2

This patch also provides 3 buffer-mode which provides header separation
functionality. In 3 buffer-mode skb->data will have L2/L3/L4 headers and
"skb_shinfo(skb)->frag_list->data" will have have L4 payload.
one can load driver in 3 buffer-mode with same above module-load parameter

ie.
#insmod s2io.ko rx_ring_mode=3

Please review the patch.
Signed-off-by: NAnanda Raju <ananda.raju@neterion.com>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>