For unifying common FGPA drivers, a FPGA subsystem has been proposed for the Linux kernel.
Michal Simek has proposed a FPGA subsystem core for the Linux kernel in order to unify all FPGA drivers that generally all do the same task. The example Simek used in calling for this new subsystem was, "Xilinx has hwicap in the kernel as char driver (drivers/char/xilinx_hwicap/) and I would like to base Zynq devcfg driver based on this interface because make no sense to push the Linux kernel another char driver (I am testing this interface on this driver)."
There isn't too much to this subsystem yet but Michael Simek has already discussed its prospects with Greg Kroah-Hartman. For those FPGA developers wishing to learn more, see the kernel patch series