The patches published one month ago for Nouveau NVIDIA Fermi Compute Support
on the open-source driver have now been committed to master for the next Mesa release. More importantly this is the base work for implementing NVIDIA performance counters.
Before getting too excited, these patches are queued up in Mesa Git master which now means Mesa 9.3 (or more likely Mesa 10.0 pending OpenGL 3.2/3.3 compliance) and not Mesa 9.2 that will be released later in the month. Additionally, this Compute/GPGPU support for the Nouveau "NVC0" driver is very rudimentary and not everything you need to get OpenCL running on the reverse-engineered Nouveau driver.
As said by Nouveau's Martin Peres in the forums
last month after the initial patches were posted, "the proposed patches are the bare minimum to read the MP counters on nvc0 (which require executing a hard-coded kernel)."
With this compute support committed, now also in Mesa Git master are some MP performance counters
for modern NVIDIA GPUs. The work is part of this year's X.Org Google Summer of Code
via the student developer Samuel Pitoiset.