CVS commit: src/sys/arch

["Jared D. McNeill" <jmcneill%netbsd.org@localhost>]

Module Name:    src
Committed By:   jmcneill
Date:           Mon Dec 30 19:17:21 UTC 2024

Modified Files:
        src/sys/arch/aarch64/include: cpu.h
        src/sys/arch/arm/acpi: cpu_acpi.c

Log Message:
arm64: Enable support for low power idle CPU states on ACPI platforms.

The ACPI CPU driver parses the _LPI package on each CPU and builds a
table of supported low power states. A custom cpu_idle() implementation
is registered that uses the time previously spent idle to select an
entry method for low power on the next idle entry.

A boot option, "nolpi", can be used to ignore _LPI and use the normal
WFI idle method.

This decreases the battery discharge rate on my Snapdragon X1E laptop from
~17W to ~10W when idle.


To generate a diff of this commit:
cvs rdiff -u -r1.52 -r1.53 src/sys/arch/aarch64/include/cpu.h
cvs rdiff -u -r1.16 -r1.17 src/sys/arch/arm/acpi/cpu_acpi.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.