xref: /freebsd/share/man/man4/hwpstate_intel.4 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
14577cf37SConrad Meyer.\"
24577cf37SConrad Meyer.\" Copyright (c) 2019 Intel Corporation
34577cf37SConrad Meyer.\"
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54577cf37SConrad Meyer.\" modification, are permitted provided that the following conditions
64577cf37SConrad Meyer.\" are met:
74577cf37SConrad Meyer.\" 1. Redistributions of source code must retain the above copyright
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94577cf37SConrad Meyer.\" 2. Redistributions in binary form must reproduce the above copyright
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25*62d12eabSLi-Wen Hsu.Dd April 21, 2020
264577cf37SConrad Meyer.Dt HWPSTATE_INTEL 4
274577cf37SConrad Meyer.Os
284577cf37SConrad Meyer.Sh NAME
294577cf37SConrad Meyer.Nm hwpstate_intel
304577cf37SConrad Meyer.Nd Intel Speed Shift Technology driver
314577cf37SConrad Meyer.Sh SYNOPSIS
324577cf37SConrad MeyerTo compile this driver into your kernel
334577cf37SConrad Meyerplace the following line in your kernel
344577cf37SConrad Meyerconfiguration file:
354577cf37SConrad Meyer.Bd -ragged -offset indent
364577cf37SConrad Meyer.Cd "device cpufreq"
374577cf37SConrad Meyer.Ed
384577cf37SConrad Meyer.Sh DESCRIPTION
394577cf37SConrad MeyerThe
404577cf37SConrad Meyer.Nm
414577cf37SConrad Meyerdriver provides support for hardware-controlled performance states on Intel
424577cf37SConrad Meyerplatforms, also known as Intel Speed Shift Technology.
434577cf37SConrad Meyer.Sh LOADER TUNABLES
444577cf37SConrad Meyer.Bl -tag -width indent
454577cf37SConrad Meyer.It Va hint.hwpstate_intel.0.disabled
464577cf37SConrad MeyerCan be used to disable
474577cf37SConrad Meyer.Nm ,
484577cf37SConrad Meyerallowing other compatible drivers to manage performance states, like
494577cf37SConrad Meyer.Xr est 4 .
50cd4e43b2SConrad MeyerDefaults to
51cd4e43b2SConrad Meyer.Dv Qq 0
52cd4e43b2SConrad Meyer(enabled).
53cd4e43b2SConrad Meyer.It Va machdep.hwpstate_pkg_ctrl
54cd4e43b2SConrad MeyerSelects between package-level control (the default) and per-core control.
55cd4e43b2SConrad Meyer.Dv Qq 1
56cd4e43b2SConrad Meyerselects package-level control and
57cd4e43b2SConrad Meyer.Dv Qq 0
58cd4e43b2SConrad Meyerselects core-level control.
594577cf37SConrad Meyer.El
604577cf37SConrad Meyer.Sh SYSCTL VARIABLES
614577cf37SConrad MeyerThe following
624577cf37SConrad Meyer.Xr sysctl 8
634577cf37SConrad Meyervalues are available
644577cf37SConrad Meyer.Bl -tag -width indent
658e3442b7SLi-Wen Hsu.It Va dev.hwpstate_intel.%d.%desc
664577cf37SConrad MeyerDescribes the attached driver
674577cf37SConrad Meyer.It dev.hwpstate_intel.0.%desc: Intel Speed Shift
688e3442b7SLi-Wen Hsu.It Va dev.hwpstate_intel.%d.%driver
694577cf37SConrad MeyerDriver in use, always hwpstate_intel.
704577cf37SConrad Meyer.It dev.hwpstate_intel.0.%driver: hwpstate_intel
718e3442b7SLi-Wen Hsu.It Va dev.hwpstate_intel.%d.%parent
728e3442b7SLi-Wen HsuThe CPU that is exposing these frequencies.
734577cf37SConrad MeyerFor example
744577cf37SConrad Meyer.Va cpu0 .
758e3442b7SLi-Wen Hsu.It dev.hwpstate_intel.0.%parent: cpu0
764577cf37SConrad Meyer.It Va dev.hwpstate_intel.%d.epp
774577cf37SConrad MeyerEnergy/Performance Preference.
784577cf37SConrad MeyerValid values range from 0 to 100.
794577cf37SConrad MeyerSetting this field conveys a hint to the hardware regarding a preference towards
804577cf37SConrad Meyerperformance (at value 0), energy efficiency (at value 100), or somewhere in
814577cf37SConrad Meyerbetween.
824577cf37SConrad Meyer.It dev.hwpstate_intel.0.epp: 0
834577cf37SConrad Meyer.El
844577cf37SConrad Meyer.Sh COMPATIBILITY
854577cf37SConrad Meyer.Nm
864577cf37SConrad Meyeris only found on supported Intel CPUs.
874577cf37SConrad Meyer.Sh SEE ALSO
884577cf37SConrad Meyer.Xr cpufreq 4
894577cf37SConrad Meyer.Rs
904577cf37SConrad Meyer.%T "Intel 64 and IA-32 Architectures Software Developer Manuals"
914577cf37SConrad Meyer.%U "http://www.intel.com/content/www/us/en/processors/architectures-software-developer-manuals.html"
924577cf37SConrad Meyer.Re
934577cf37SConrad Meyer.Sh AUTHORS
944577cf37SConrad MeyerThis manual page was written by
954577cf37SConrad Meyer.An D Scott Phillips Aq Mt scottph@FreeBSD.org .
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