DMA

The HBA driver must describe the attributes of its DMA engine by properly initializing the ddi_dma_attr_t structure.

static ddi_dma_attr_t isp_dma_attr = {
     DMA_ATTR_V0,        /* ddi_dma_attr version */
     0,                  /* low address */
     0xffffffff,         /* high address */
     0x00ffffff,         /* counter upper bound */
     1,                  /* alignment requirements */
     0x3f,               /* burst sizes */
     1,                  /* minimum DMA access */
     0xffffffff,         /* maximum DMA access */
     (1<<24)-1,          /* segment boundary restrictions */
     1,                  /* scatter-gather list length */
     512,                /* device granularity */
     0                   /* DMA flags */
};

The driver, if providing DMA, should also check that its hardware is installed in a DMA-capable slot:

if (ddi_slaveonly(dip) == DDI_SUCCESS) {
    return (DDI_FAILURE);
}