Arm is an active maintainer and contributor to the Linux Kernel project, together with Linaro and a large number of partner companies and independent developers.
Arm maintains the arch/arm64 Linux Kernel tree, for all Arm 64-bit enabled systems and it actively contributes to the arch/Arm tree for all legacy Arm 32-bit systems (Armv7 and Armv8 running at AArch32).
Arm also maintains the KVM/arm and KVM/arm64 ports of the popular Kernel Virtual Machine (KVM) hypervisor.
Arm develops and maintains the fundamental Arm Architecture enablement for the Linux kernel.
All the information regarding the Linux Kernel can be found in the official Kernel.org website.