Add "Tyr GPU Driver" page

Content provided by Daniel Almeida.

Signed-off-by: Miguel Ojeda <[email protected]>

Author: ojeda

SUMMARY.md

@@ -36,6 +36,7 @@
   - [DRM Panic QR code generator](DRM-Panic-QR-code-generator.md)
   - [Nova GPU Driver](Nova-GPU-Driver.md)
   - [Null Block Driver](Null-Block-Driver.md)
+  - [Tyr GPU Driver](Tyr-GPU-Driver.md)
 
 ## Users — outside mainline
 

src/Tyr-GPU-Driver.md

@@ -0,0 +1,83 @@
+# Tyr GPU Driver
+
+## What is Tyr?
+
+Tyr is a new Rust-based DRM driver for CSF-based Arm Mali GPUs. It is a port of
+Panthor — a driver written in C for the same hardware — and written as a joint
+effort between Collabora, Arm and Google engineers.
+
+Tyr aims to eventually implement the same userspace API offered by Panthor for
+compatibility reasons, so that it can be used as a drop-in replacement in our
+Vulkan driver, called
+[PanVK](https://gitlab.freedesktop.org/mesa/mesa/-/tree/main/src/panfrost/vulkan?ref_type=heads).
+In any case, we foresee Panthor being used — and of course supported — for a
+relatively long time, as it is a mature driver with a large adoption in the
+ecosystem. It will probably take a couple of years for Tyr to fully pick up.
+
+## Where is Tyr developed?
+
+The development of Tyr takes place both upstream, through our [latest
+submission](https://lore.kernel.org/rust-for-linux/[email protected]/)
+— and downstream, on the `tyr-next` branch at the [Panfrost Gitlab repository](https://gitlab.freedesktop.org/panfrost/linux).
+
+This split is unfortunately necessary as we do not have the required
+infrastructure in upstream yet, although our plan is to eventually migrate to
+an upstream-only development model once this changes.
+
+We go into more details about why we chose to develop Tyr this way on our
+series of [blog
+posts](https://www.collabora.com/news-and-blog/news-and-events/introducing-tyr-a-new-rust-drm-driver.html)
+at [Collabora's blog](https://www.collabora.com/news-and-blog/). Anyone willing
+to get acquainted with Mali's open source stack should refer to that, as we
+will be covering the whole infrastructure from a simple Vulkan application to
+the actual GPU hardware in Mali's CSF architecture. We will also cover the
+various components needed to write a driver, as well as the status of the
+abstractions needed to interact with them from Rust code.
+
+As it currently stands, our downstream branch can be used to test the
+abstractions that are still being developed. It makes sure that we can write a
+functional driver with the abstractions that are currently being proposed.
+
+## What is the current status of the driver?
+
+The current upstream submission can power up the GPU and probe the device on an
+RK3588 system-on-chip. This lets us read a few sections of ROM in the GPU,
+which in turn lets us provide this information to userspace by means of a
+`DRM_IOCTL_PANTHOR_DEV_QUERY` call.
+
+This is all that can be done for now in upstream code, at least until the Micro
+Controller Unit can be made to work.
+
+Our downstream branch (`tyr-next`) can submit small parcels of work to the GPU,
+and we will soon be able to submit more elaborate workflows. We hope to see
+[VkCube](https://github.com/KhronosGroup/Vulkan-Tools) running on Tyr soon.
+
+In any case, there is no power management and little error recovery. We will be
+working on that in the coming months.
+
+## Can I try it out?
+
+Anyone with a RK3588 SoC can test Tyr, but the driver is not capable of
+replacing Panthor yet. A good candidate device is Radxa's
+[ROCK 5B](https://radxa.com/products/rock5/5b/) Single Board Computer.
+
+A good starting point is to run our [IGT
+tests](https://gitlab.freedesktop.org/dwlsalmeida/igt-gpu-tools/-/tree/panthor?ref_type=heads).
+While only a subset of the tests pass on the upstream code for the reasons
+highlighted above, they should all pass if run on `tyr-next`.
+
+Note that Mali GPUs are found in a vast array of devices, and that we will
+support more hardware as we progress in the implementation.
+
+## Contributing
+
+Tyr is open-source software, and as such, anyone interested in its development
+can check our [issue
+board](https://gitlab.freedesktop.org/panfrost/linux/-/issues/?label_name%5B%5D=tyr).
+We will be posting good starting tasks at a future point.
+
+To work on any given task, assign it to yourself and follow up with a merge
+request against `tyr-next`. Please also write the IGT tests needed to ensure that
+your code works.
+
+Happy hacking!