Linux 5.8 To See Support For POWER10's Prefixed Instructions

Beyond the usual excitement of numerous x86 and Arm hardware advancements each cycle, Linux 5.8 is bringing new IBM POWER enablement work.

Recently there has been an uptick in open-source/Linux enablement work for the forthcoming POWER10 and that holds true for Linux 5.8. There has been a patch series going around recently for introducing prefixed instruction support on the POWER front for a "future revision of the ISA." That work is now ready and queued ahead of the Linux 5.8 cycle opening up in early June.

As explained by the patch series working on this prefixed instruction support, "A prefixed instruction is composed of a 4-byte prefix followed by a 4-byte suffix. All prefixes have the major opcode 1. A prefix will never be a valid word instruction. A suffix may be an existing word instruction or a new instruction. This series enables prefixed instructions and extends the instruction emulation to support them. Then the places where prefixed instructions might need to be emulated are updated."

That prefixed instruction work is now queued in PowerPC-next for the 5.8 cycle.

POWER10 processors are expected to debut next year or late this year and built on a 7nm process and with many design improvements over existing POWER9 hardware. With the launch getting closer, expect more Linux enablement work to heat up.