RX_BD_TOTAL_PER_PAGE
&fp->rx_chain[RX_BD_TOTAL_PER_PAGE * j - 2];
#define RX_BD_USABLE_PER_PAGE (RX_BD_TOTAL_PER_PAGE - RX_BD_NEXT_PAGE_DESC_CNT)
#define RX_BD_PER_PAGE_MASK (RX_BD_TOTAL_PER_PAGE - 1)
#define RX_BD_TOTAL (RX_BD_TOTAL_PER_PAGE * RX_BD_NUM_PAGES)