Intel Software Defined Silicon, AMD HSMP Submitted For Linux 5.18

Written by Michael Larabel in Hardware on 25 March 2022 at 09:38 AM EDT. 6 Comments
The x86 platform driver updates have been submitted for the Linux 5.18 kernel merge window. This pull request includes a number of notable additions we have been talking about over recent weeks and months on Phoronix.

First up, the x86 platform driver changes for Linux 5.18 does include the Intel Software Defined Silicon (SDSi) driver. This was expected and now landing ahead of next-generation processors expected to carry this controversial feature. Software Defined Silicon allows for activating extra silicon hardware features baked into the processor but not activated by default until the SDSi driver provides the proper cryptographically-baked key to the processor. SDSi only came to light after we first reported on the kernel code last year. So far Intel hasn't clarified how it intends to market SDSi with what features we may see concealed behind this activation license model for future CPUs, so for now we wait and the kernel activation driver is here with Linux 5.18 for the kernel driver and sample user-space SDSi provisioning tool. At least initially this is likely to be just for Intel server/workstation processors.

Prominent PDx86 changes for the Linux 5.18 cycle both on the Intel and AMD sides.

Over on the AMD side a notable addition with this platform-drivers-x86 pull request is the AMD HSMP system management driver. The AMD Host System Management Port (HSMP) is with AMD server processors for providing additional system management functionality under Linux. The AMD HSMP currently supports messages for reading the current average socket power consumption, setting the socket power limit, getting/setting a maximum frequency limit, setting the min/max width of the xGMI link, enabling the DF P-State Performance Boost support, getting the FCLK and MEMCLK for the current socket, reading the average C0 residency for that socket, getting per-DIMM temperatures and refresh rates, and getting the maximum/current DDR bandwidth usage, among other possible options (messages).

Also notable on the AMD side are suspend-to-idle (s2idle) bug fixes and a "Spill to DRAM" feature for the AMD Smart Trace Buffer (STB) code. STB Spill to DRAM allows for spilling data fram SRAM to DRAM on future AMD ASICs for collecting extra tracing/telemetry data.

As part of the ThinkPad driver in this pull, there is also ACPI Platform Profile support now working correctly for AMD-powered ThinkPads.

This pull request also has more quirky x86 Android tablet workarounds/fixes.

See the pull request for the full list of x86 platform driver updates heading into the Linux 5.18 kernel. Linux 5.18 stable should be out around the end of May.
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Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

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