altera_dma driver for PCIe

Which kit are you using the Arria V or the Arria 10 Dev Kit? When building the example design, did you notice the PCIe config space registers. They usually have these Vendor ID and DEvice ID registers in it, with the Vendor ID preset to the Altera one and Device ID being 00000 . If this is the case with your design, then you may need to set the appropriate DEvice ID in your PCIe component (E0073 for Arria V / E0093 for Arria 10/ or E001 for default) and build the system again. Program the FPGA on the board. Then in the driver code make sure you use the same Device ID that is in the HW and build the driver again. This way the Device ID will match. Once the Device is enumerated successfully, the BAR registers will get enabled and you should be able to read and write from them, perform DMA etc.