bwn_dma_ring_addr
BWN_GET_TXHDRCACHE(slot), BWN_HDRSIZE(mac), bwn_dma_ring_addr,
static void bwn_dma_ring_addr(void *, bus_dma_segment_t *, int, int);
bwn_dma_ring_addr, &dr->dr_ring_dmabase, BUS_DMA_NOWAIT);