AMD Has Many New CPU/GPU Features Ready For Linux 6.3

With the Linux 6.3 merge window opening up following tomorrow's stable debut of the Linux 6.2 kernel, there is a lot to be excited about if you are a customer of AMD's recent CPUs or GPUs.

With the new feature code expected to land over the next two weeks for the Linux 6.3 kernel, this cycle is going to be particularly rich on the AMD side. Both for their processors -- especially current Zen 4 CPUs -- as well as on the graphics side of the house, there is a lot of driver improvements coming with this next kernel version.

Linux 6.3 stable won't be out until April but some of the AMD code that's slated to land during this merge window based on my monitoring includes:

- AMD Automatic IBRS to help squeeze a bit more performance out of AMD Zen 4 CPUs. Automatic IBRS allows less costly Spectre V2 mitigations than using Retpolines.

- AMD P-State EPP is being added to help the performance and power efficiency of modern AMD desktops / laptops / servers. This is for supporting the Energy Preference Performance (EPP) mode beyond the base amd_pstate driver already mainlined. This should take care of some of the deficiencies currently seen with the AMD P-State CPU frequency scaling driver code. AMD P-State EPP and Auto IBRS make Linux 6.3 exciting on the performance front.

- Support for Microsoft's Pluton CRB TPM2 found within the newest AMD Ryzen processors. This just exposes the TPM2 functionality and not any of the other "scary" Pluton functionality under Linux.

- More graceful handling of the AMD graphics driver for new hardware where the kernel driver may be missing GPU support or not having the necessary GPU firmware binaries. This is very nice for early Radeon customers of future hardware or even now for RDNA3 if you switch to a new kernel but haven't yet upgraded the linux-firmware.git binaries.

- AMDGPU will now expose more PCIe information to user-space that the Radeon Mesa drivers can leverage for optimized buffer placement and other benefits from this new uAPI.

- AMD SMBA and BMEC QoS features around Slow Memory Bandwidth Allocation and Bandwidth Monitoring Event Configuration for Zen 4 server processors is now ready for the mainline kernel.

- Continued AMD RDNA3 graphics enablement work.

- AMD's graphics driver will now allow some power savings benefits for systems without S0ix BIOS support.

- While not directly AMD related, but with the AMD SoC powering Valve's wildly popular Steam Deck... There is initial Steam Deck controller interface support going into the mainline kernel with Linux 6.3.

- Some work on the AMD-Xilinx side like introducing EDAC support for the Xilinx ZynqMP on-chip memory controller.

Stay tuned to Phoronix for more details on all of the interesting changes to come during the merge window over the next two weeks. Intel customers also have a lot to look forward too and will be out with that similar article tomorrow. Linux 6.3 will make for a very nice spring release of the kernel but sadly will be too late for finding on Ubuntu 23.04 or Debian 12 but will be available on the likes of Fedora 38 as an update.

Once the Linux 6.3 merge window ends in early March, it's onto benchmarking the experimental kernel with its P-State EPP, Auto IBRS, and other performance-related enhancements.