I have been trying to read and write data to pci-e, but I cannot find anything. I dont know where to start or how it works. Any help on how is appreciated. Thanks.
I can't give any direct help, and I'm sure you probably already know to do this, but you're going to want to read up on how the linux kernel handles hardware interrupts and interfacing with it in general. One thing you could do (and yes I know it's unruly) is pick up some open source graphics cards drivers and find where they work with communication through the pci-e slot.