Linux 4.3 Implements New ARMv8.1 Features

Written by Michael Larabel in Arm on 4 September 2015 at 08:29 AM EDT. Add A Comment
Already mailed in for the Linux 4.3 kernel merge window this week were the numerous ARM SoC updates while being sent in over the night were the ARM64/AArch64 architectural changes for this next version of the Linux kernel.

Linux 4.3 will see support for new architectural features that were added to ARMv8.1, a minor update to the ARMv8 specification that brought 64-bit to the ARM world. Implemented from ARMv8.1 for Linux 4.3 is PAN, LSE, and DBM support. PAN is short for Privileged Access Never (PAN) and is an ARM way for catching user point dereferences in the kernel. LSE is the Large System Extension and is for building scalable atomics and locks. Lastly DBM of ARMv8.1 is Hardware Dirty Bit Management and is for updating clean PTEs automatically.

While the Linux 64-bit ARM support is coming along, I'm still waiting to see a nice, performant, reasonably-priced development board with a compelling 64-bit ARM SoC... The Tegra X1 development board is likely to be first (assuming it's real and that all pans out) otherwise we're also waiting on this AMD ARM board.

Aside from the PAN / LSE / DBM ARM64 support, the pull request has various other updates, and now also forces SMP support to be enabled.
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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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