USABLE_RX_BD_PER_PAGE
#define USABLE_RX_BD_ALLOC (USABLE_RX_BD_PER_PAGE * sc->rx_pages)
#define NEXT_RX_BD(x) (((x) & USABLE_RX_BD_PER_PAGE) == \
(USABLE_RX_BD_PER_PAGE - 1)) ? (x) + 2 : (x) + 1
#define RX_PAGE(x) (((x) & ~USABLE_RX_BD_PER_PAGE) >> (BCM_PAGE_BITS - 4))
#define RX_IDX(x) ((x) & USABLE_RX_BD_PER_PAGE)