The tran_dmafree( ) vector in the scsi_hba_tran(9S) structure must be initialized during the HBA driver's attach(9E) to point to an HBA entry point to be called when a target driver calls scsi_dmafree(9F).
tran_dmafree( ) must deallocate any DMA resources previously allocated to this pkt in a call to tran_init_pkt( ). tran_dmafree( ) should not free the structure pointed to by pkt itself.