MSM DRM Driver Bringing Zap Shader Support To Exit Secure Mode On Adreno 600 Series

The Freedreno MSM DRM driver changes have been submitted to DRM-Next ahead of Linux 5.2. MSM provides the Direct Rendering Manager support around Qualcomm Adreno hardware and with this next kernel cycle is continuing to see better Adreno 600 series support.

The primary addition to MSM with Linux 5.2 is zap shader support. A "zap" shader is a way for Adreno hardware to exit its secure mode via a series of specialized commands as accessing the registers directly for exiting the GPU secure mode is generally locked down by the bootloader.

MSM has already supported the zap shader for the Adreno 500 series while now is working for A6xx hardware too for leaving the restricted GPU environment. The patches themselves came from Qualcomm / Code Aurora who continue making contributions to this open-source, in-kernel driver.

This MSM DRM-Next material also includes the necessary kernel-side bits for Freedreno Gallium3D driver to support the OpenGL robustness extensions.

The complete list of MSM changes for Linux 5.2 can be found from this pull request.