COLLABORA announced the availability of an open driver called Panthor, developed for the tenth generation GPU Mali (G310, G510, G710). This driver utilizes the Command Stream Frontend (CSF) technology, which offloads work from the CPU and introduces a new model for organizing tasks on the GPU. Panthor DRM-Driver has been accepted into the DRM-MISC branch and is expected to be included in the Linux 6.10 kernel. Changes to support this new driver have also been integrated into the Mesa and Gallium Panfrost driver for GPU MALI.
The new generation of Mali GPUs replaces the Job Manager scheduler with the CSF interface, which shifts from a task chain-based model to a command flow-based model with line flow planning on the firmware stream. A Cortex-M7 microcontroller is integrated into the scheduler’s function within the GPU, along with a specialized unit for executing CSF instructions. This necessitates a different approach to organizing work transfer in the GPU from the user space.
Initially, efforts were made to implement CSF support for the Mali GPU in the Panfrost DRM driver, but developers determined that it would overly complicate the existing driver. As a result, creating a new driver with a different architecture dedicated to CSF was deemed more optimal. The Panthor driver introduces a new user API, work planning logic, and MMU/GPU-VA management logic, based on code from the existing Panfrost DRM driver with adaptations for the new functionality.
Following initial reverse engineering efforts, ARM company joined the project, providing documentation access and contributing to the codebase. Two ARM employees have been designated as driver co-maintainers for the Linux kernel. Future development will focus on implementing the Vulkan Driver for the new Mali GPU, modernizing the existing Vulkan Driver for older Mali GPUs, and completing the Opengl Driver.
In addition to GPU support, the Panthor driver enables compatibility with COC Rockchip RK3588. Collabora also undertook work to support boards based on Rockchip RK3588 using an open software stack. A system image based on Debian and an open bootloader have been prepared for Rockchip