Hello Everyone, I am working on a device with a PLX PCIe switch and multiple PCIe endpoints enumerated off an ARM RP. I am playing with endpoint-to-endpoint communications. I have verified after the PCIe bus is enumerated that I can send TLPs from one endpoint to an enumerated BAR on another endpoint and the TLP is directed to the other endpoint. I have further verified that the RP receivies nothing as desired. The issue I am looking for some advice on is how to tell each endpoint what all the other endpoints BAR address is. For the sake of argument, lets say I have N modules and each module needs to know the enumerated endpoint address of the other N-1 modules Bar0 address. The brute force/prototype method I have been testing is scrape /proc/iomem after enumeration and write to each card's registers via /dev/mem the address of all other cards. This works, but is not something I would put on my resume. I am now trying to "do it right". This scraping also assumes bus addresses and host addresses are the same. This seems to be true on my architecture. My preliminary driver design has a common base layer that each endpoint's driver registers with when it is probed. After the BAR addresses are assigned the endpoint driver tells the common base layer its assigned address and the base layer writes that into registers in all the other registered endpoints via their respective drivers. Before I go off boldly and and completely re-invent the wheel I was wondering if something like this had been contemplated or created yet, perhaps via callback hooks or some other PCIe framework thingy I am not aware of. Or is there another way to achieve the same goal? Anyone have any feedback? Thanks for your time! Barry -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
