AMD SMCA Updates Land In Linux 5.17 For Future CPUs

Last week I noted about EDAC changes in Linux 5.17 for future AMD CPUs. The "Error Detection and Correction" work included AMD adding RDDR5 / LRDDR5 support to their driver and new CPU model IDs that appear to be for Zen 4. Also working on next-gen AMD processor support in Linux 5.17 are recent SMCA changes.

Back in early December I wrote about AMD volleying new SMCA driver changes for a new generation of AMD processors. Those changes are interesting for their Scalable Machine Check Architecture as it introduces the notion of having possibly different bank type layouts depending upon the logical CPU core. Thus the preparations are being made -- and now merged in Linux 5.17 -- for where the machine check architecture bank types/layout are different depending upon the particular CPU. The patches don't provide AMD's reasoning for this change but it's possible for hybrid core designs or other reasons.

The patch series also introduces a number of new SMCA bank types. Among those new bank types are for an updated "v2" unified memory controller, an updated PCIe unit, and various xGMI units.

Those AMD SMCA changes for future AMD CPUs were merged last week as part of ras/core updates for Linux 5.17.

Other next-gen AMD CPU work in Linux 5.17 beyond the SMCA and EDAC additions is temperature monitoring support for those new CPU model IDs touched by the EDAC work. It's good seeing this work happening now ahead of Zen 4 processors launching later in 2022.