ACP port under Linux

Thanks for you quick reply Sir.

Now, why did you say the FPGA-SDRAM port is faster than ACP port, I have read that by using the ACP port you can get data that is cached, so you don't have to read/write data to the DDR SDRAM in some cases.

I am using the DE1-SoC board.

If by using the FPGA-SDRAM ports I will get better performance, can you explain me how to use the dma_sync_single_for_device/cpu functions.

I am working of a project where I have a user application which will send some information to the FPGA module I have developed (some like a DMA module, but it doesn't move data in the way *dest++ = *src++), so how can I allocate physical memory that I can share between the FPGA and CPU? and what it the use of the dma_sync... functions?