npehwbuf
struct npehwbuf *hw;
size = nbuf * sizeof(struct npehwbuf);
struct npehwbuf *hw = &dma->hwbuf[i];
&(dma)->buf[((a) - (dma)->buf_phys) / sizeof(struct npehwbuf)]
struct npehwbuf *ix_hw; /* associated h/w block */
struct npehwbuf *hw;
&(dma)->buf[((a) - (dma)->buf_phys) / sizeof(struct npehwbuf)]
struct npehwbuf *hwbuf; /* NPE h/w buffers */
struct npehwbuf *hw = npe->ix_hw;