Dma Stratix IV

Hi everybody,

I am new on forums.

I wanted to do a DMA with a StratixIV on a CentOS 6.5 in C with a driver.

So to start, I search how to enable, set and configure the pci device.

Which I did (with pci_enable, ...).

I succeed to write in the virtual address provide by the BAR0 (pci_iomap).

Then I wanted to make a DMA between the cpu and the Fpga ram, so I searched how to allocate and use a Dma buffer, thanks of the function dma_alloc_coherent.

But among all the documentation I read, it didn't mention how to start / launch the dma.

So I have a virtual address (provided by dma_alloc_coherent) and if I wrote in it it's very fast. For example to copy a file of 100 Mo.

I concluded I was in the local RAM.

Maybe I do a step wrong so do you have some explanations about the step of the dma ?

I read a lot of free electron source and the DMA-API.txt.

My BAR 0 has 256 MB.

Thank you for your help.

Sincerely