DMA

If the driver provides DMA, for example, it must specify DMA attributes describing the capabilities and limitations of its DMA engine.

In the Solaris 7 system, the HBA driver must provide DMA.

	
			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);
 		}