AArch64 Architecture Code Improvements Land In Linux 6.2
In addition to other pull requests adding support for more Arm Socs and various boards/devices, the ARM64 architecture updates were also merged this week for the in-development Linux 6.2. Some of the ARM64 changes this cycle include:
- Firmware Performance Data Table (FPDT) support is added to allow for boot-time profiling of AArch64 hardware.
- Advertising of new Arm Scalable Vector Extensions v2.1 (SVE 2.1). Common Short Sequence Compression (CSSC) scalar instructions are also now advertised by the kernel along with the AArch64 range prefetch instruction. This work is around Arm's 2022 data processing instructions.
- Support for dynamic shadow call stacks for switching at run-time between LLVM Clang's shadow call stack (SCS) feature and the CPU's pointer authentication functionality.
- Support for the Arm CoreSight PMU architecture as well as NVIDIA's implementation of this architecture. This CoreSight performance monitoring unit driver is not related to CoreSight Self-Hosted Tracing and is a new optional hardware uncore feature.
More details on the ARM64 changes this round via the already honored pull request.
The aging Ampere eMAG 64-bit Arm server processor, since succeeded by Ampere Altra.
Also worth mentioning as well is the Xen pull request for Linux 5.2 that adds support for VirtIO PCI devices in Xen guests running on Arm. Aside from that the Xen material this round is rather small.