Mesa Begins Trek Bringing Up Arm Mali "Valhall" Graphics

The Panfrost Gallium3D OpenGL driver and PanVK open-source drivers in Mesa have come a long way via reverse-engineering for Arm Mali graphics support. However, to this point the focus has been on Arm's "Midgard" and "Bifrost" architectures while the newer "Valhall" architecture has been around the past two years. The Panfrost effort for bringing up Valhall is now getting underway.

Alyssa Rosenzweig who has led the Panfrost effort for open-source Arm Mali graphics has been working for a while now on getting Arm's Valhall architecture reverse-engineered and supported by the Linux graphics driver code. (That's also in addition to her separate work on reverse-engineering the Apple M1 graphics as another ongoing open-source adventure.)

Now merged is the initial XML bits laying out the new architecture for Panfrost as well as the Pandecode support used for reverse-engineering / command stream debugging.

Add XML for the next major architecture version of Mali, v9, and add support for the new architecture to pandecode. I held off sending this merge request while reverse-engineering actively to avoid spamming mesa with commits discovering new unknown fields. That r/e cycle has settled down so I'd like to move forward with this... my branch adding Valhall support to Mesa is big enough as it is.

The Valhall enablement bits for the Panfrost driver are still being worked on via Alyssa's Mesa Gitlab branch. We'll see if those bits are readied in time for Mesa 22.0 next quarter but at least the early bits are now hitting mainline.

Arm's Valhall premiered with the Mali G57/G77 GPUs and has continued through with the latest Mali G710 graphics processor. Valhall features various engine changes, a simplified scalar ISA, and other design improvements over Bifrost.