RSWITCH_HEADROOM
#define RSWITCH_BUF_SIZE (RSWITCH_HEADROOM + RSWITCH_DESC_BUF_SIZE + \
#define RSWITCH_MAP_BUF_SIZE (RSWITCH_BUF_SIZE - RSWITCH_HEADROOM)
gq->rx_bufs[i] + RSWITCH_HEADROOM,
gq->rx_bufs[index] + RSWITCH_HEADROOM,
skb_reserve(skb, RSWITCH_HEADROOM);
offset_in_page(gq->rx_bufs[gq->cur]) + RSWITCH_HEADROOM,