Thanks to James Simmons, an independent developer in the open-source community, last month a patch was published that adds TTM/GEM memory management support
to the VIA DRM Linux kernel driver. This was after VIA basically admitted defeat
for their Linux / open-source strategy. Over the weekend the second version of this TTM/GEM patch was published by James.
This TTM/GEM patch for VIA hardware in the second revision now works when unloading the VIA kernel module or restarting the X Server, moves all resource handling over to TTM (Translation Table Maps), utilizes the GEM creation ioctl, reworks the detection of resources, and reworks the video memory (VRAM) detection to use the VIA north-bridge for detecting the memory and capacity.
Still lacking from this open-source VIA Linux code is accelerated bmoves, fence object handling (needed for 3D), and support for VIA PCI DMA GART. James and the OpenChrome developers also need to decide how to proceed on the DDX driver side, which is described in this mailing list post
It looks like this work will actually move forward and should reach the mainline Linux kernel at some point.