Lukas Wunner submitted a 6-part patch to the Linux-(EFI,Kernel) lists with additional Apple EFI firmware support.
Apple device properties
Apple EFI drivers supply device properties which are needed to support Macs optimally. This series extends the efistub to retrieve the device properties before ExitBootServices is called (patch [1/6]). They are assigned to devices in an fs_initcall (patch [5/6]). As a first use case, the Thunderbolt driver is amended to take advantage of the Device ROM supplied by EFI (patch [6/6]). A by-product is a parser for EFI Device Paths which finds the struct device corresponding to a given path. This is needed to assign properties to their devices (patch [3/6]). […]