Etnaviv Landing Performance Counters For Linux 4.15

Lucas Stach has sent in the Etnaviv DRM driver changes to DRM-Next for the Linux 4.15 kernel. This is one of the bigger pull requests for this reverse-engineered, open-source Vivante graphics driver.

This community-driven Vivante graphics driver continues to become more capable and feature complete with each kernel cycle. For Linux 4.15 the new work includes landing GPU performance counter support, which is important for developers in being able to analyze/tune the performance. They've been reverse engineering the Vivante performance counters for a while and now it's ready to go for Linux 4.15. There are experimental patches currently for libdrm in making use of the new API.

Besides the perf counters work, there is now an optimized probe path, various driver clean-ups, some MMU optimizations, and around one thousand lines worth of changes in total -- about half of which is the hardware counters.

These Etnaviv changes for Linux 4.15 can be found listed on dri-devel. It will be interesting monitoring the Etnaviv progress over the next few kernel cycles especially with Purism planning to make use of this open-source graphics driver for their i.MX6/i.MX8 Librem 5 smartphone.