ARM: How to use reserved-memory in devicetree

[Cyberman Wu]

I'm using Xilinx Zynq-7000 platform and shared a region of DDR between
ARM and FPGA.
It seems kernel parameter 'memmap=nn[KMG]$ss[KMG]' doesn't implemented
under ARM platform. I'm trying to use reserved-memory node of devicetree,
but reserved memory in that way can't be accessed using mmap("/dev/mem", ...)
in application, the data read in mapped virtual address is not the
data writing by
FPGA.

Should I write a kernel driver, or use another device for mmap()?

-- 
Cyberman Wu