cpupower: add a systemd service to run cpupower

One of the most typical use cases of the 'cpupower' utility works as
follows: run 'cpupower' at boot with the desired command-line options
and then forget about it.

Add a systemd service (disabled by default) that automates this use
case (for environments where the initialization system is 'systemd'),
by running 'cpupower' at boot with the settings read from a default
configuration file.

The systemd service, the associated support script and the
corresponding default configuration file are derived from what is
provided by the Arch Linux package (under "GPL-2.0-or-later" terms),
modernized and enhanced in various ways (the script has also been
checked with 'shellcheck').

Link: dd2e2a311e

Signed-off-by: Francesco Poli (wintermute) <invernomuto@paranoici.org>
Reviewed-by: John B. Wyatt IV <jwyatt@redhat.com>
Reviewed-by: John B. Wyatt IV <sageofredondo@gmail.com>
Tested-by: John B. Wyatt IV <jwyatt@redhat.com>
Tested-by: John B. Wyatt IV <sageofredondo@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/power/cpupower/Makefile

@@ -2,6 +2,7 @@
 # Makefile for cpupower
 #
 # Copyright (C) 2005,2006 Dominik Brodowski <linux@dominikbrodowski.net>
+# Copyright (C) 2025      Francesco Poli <invernomuto@paranoici.org>
 #
 # Based largely on the Makefile for udev by:
 #
@@ -71,6 +72,7 @@ bindir ?=	/usr/bin
 sbindir ?=	/usr/sbin
 mandir ?=	/usr/man
 libdir ?=	/usr/lib
+libexecdir ?=	/usr/libexec
 includedir ?=	/usr/include
 localedir ?=	/usr/share/locale
 docdir ?=       /usr/share/doc/packages/cpupower
@@ -83,6 +85,7 @@ CP = cp -fpR
 INSTALL = /usr/bin/install -c
 INSTALL_PROGRAM = ${INSTALL}
 INSTALL_DATA  = ${INSTALL} -m 644
+SETPERM_DATA  = chmod 644
 #bash completion scripts get sourced and so they should be rw only.
 INSTALL_SCRIPT = ${INSTALL} -m 644
 
@@ -302,6 +305,14 @@ install-tools: $(OUTPUT)cpupower
 	$(INSTALL_PROGRAM) $(OUTPUT)cpupower $(DESTDIR)${bindir}
 	$(INSTALL) -d $(DESTDIR)${bash_completion_dir}
 	$(INSTALL_SCRIPT) cpupower-completion.sh '$(DESTDIR)${bash_completion_dir}/cpupower'
+	$(INSTALL) -d $(DESTDIR)${confdir}default
+	$(INSTALL_DATA) cpupower.default '$(DESTDIR)${confdir}default/cpupower'
+	$(INSTALL) -d $(DESTDIR)${libexecdir}
+	$(INSTALL_PROGRAM) cpupower.sh '$(DESTDIR)${libexecdir}/cpupower'
+	$(INSTALL) -d $(DESTDIR)${libdir}/systemd/system
+	sed 's|___CDIR___|$(DESTDIR)${confdir}|; s|___LDIR___|$(DESTDIR)${libexecdir}|' cpupower.service.in > '$(DESTDIR)${libdir}/systemd/system/cpupower.service'
+	$(SETPERM_DATA) '$(DESTDIR)${libdir}/systemd/system/cpupower.service'
+	if test -d /run/systemd/system; then systemctl daemon-reload; fi
 
 install-man:
 	$(INSTALL_DATA) -D man/cpupower.1 $(DESTDIR)${mandir}/man1/cpupower.1
@@ -336,6 +347,9 @@ uninstall:
 	- rm -f $(DESTDIR)${includedir}/cpufreq.h
 	- rm -f $(DESTDIR)${includedir}/cpuidle.h
 	- rm -f $(DESTDIR)${bindir}/utils/cpupower
+	- rm -f $(DESTDIR)${confdir}default/cpupower
+	- rm -f $(DESTDIR)${libexecdir}/cpupower
+	- rm -f $(DESTDIR)${libdir}/systemd/system/cpupower.service
 	- rm -f $(DESTDIR)${mandir}/man1/cpupower.1
 	- rm -f $(DESTDIR)${mandir}/man1/cpupower-frequency-set.1
 	- rm -f $(DESTDIR)${mandir}/man1/cpupower-frequency-info.1
@@ -346,6 +360,7 @@ uninstall:
 	- for HLANG in $(LANGUAGES); do \
 		rm -f $(DESTDIR)${localedir}/$$HLANG/LC_MESSAGES/cpupower.mo; \
 	  done;
+	- if test -d /run/systemd/system; then systemctl daemon-reload; fi
 
 help:
 	@echo  'Building targets:'

tools/power/cpupower/README

@@ -59,6 +59,10 @@ $ sudo make install
 -----------------------------------------------------------------------
 | man pages              | /usr/man                                   |
 -----------------------------------------------------------------------
+| systemd service        | /usr/lib                                   |
+-----------------------------------------------------------------------
+| systemd support script | /usr/libexec                               |
+-----------------------------------------------------------------------
 
 To put it in other words it makes build results available system-wide,
 enabling any user to simply start using it without any additional steps
@@ -109,6 +113,10 @@ The files will be installed to the following dirs:
 -----------------------------------------------------------------------
 | man pages              | ${DESTDIR}/usr/man                         |
 -----------------------------------------------------------------------
+| systemd service        | ${DESTDIR}/usr/lib                         |
+-----------------------------------------------------------------------
+| systemd support script | ${DESTDIR}/usr/libexec                     |
+-----------------------------------------------------------------------
 
 If you look at the table for the default 'make' output dirs you will
 notice that the only difference with the non-default case is the
@@ -173,6 +181,17 @@ The issue is that binary cannot find the 'libcpupower' library. So, we
 shall point to the lib dir:
 sudo LD_LIBRARY_PATH=lib64/ ./bin/cpupower
 
+systemd service
+---------------
+
+A systemd service is also provided to run the cpupower utility at boot with
+settings read from a configuration file. In order to enable this systemd
+service, edit '${DESTDIR}/etc/default/cpupower' (uncommenting at least one of
+the options, depending on your preferences) and then issue the following
+command:
+
+$ sudo systemctl enable --now cpupower.service
+
 
 THANKS
 ------

tools/power/cpupower/cpupower.default

@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2012, Sébastien Luttringer
+# Copyright (C) 2024-2025, Francesco Poli <invernomuto@paranoici.org>
+
+# Default file for linux-cpupower
+
+# --- CPU clock frequency ---
+
+# Define CPU governor
+# Valid governors: ondemand, performance, powersave, conservative, userspace
+#GOVERNOR='ondemand'
+
+# Limit frequency range
+# Valid suffixes: Hz, kHz (default), MHz, GHz, THz
+#MIN_FREQ="2.25GHz"
+#MAX_FREQ="3GHz"
+
+# Specific frequency to be set.
+# Requires userspace governor to be available.
+# If this option is set, all the previous frequency options are ignored
+#FREQ=
+
+# --- CPU policy ---
+
+# Sets a register on supported Intel processore which allows software to convey
+# its policy for the relative importance of performance versus energy savings to
+# the processor. See man CPUPOWER-SET(1) for additional details
+#PERF_BIAS=

tools/power/cpupower/cpupower.service.in

@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2012-2020, Sébastien Luttringer
+# Copyright (C) 2024, Francesco Poli <invernomuto@paranoici.org>
+
+[Unit]
+Description=Apply cpupower configuration
+ConditionVirtualization=!container
+
+[Service]
+Type=oneshot
+EnvironmentFile=-___CDIR___default/cpupower
+ExecStart=___LDIR___/cpupower
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target

tools/power/cpupower/cpupower.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2012, Sébastien Luttringer
+# Copyright (C) 2024, Francesco Poli <invernomuto@paranoici.org>
+
+ESTATUS=0
+
+# apply CPU clock frequency options
+if test -n "$FREQ"
+then
+    cpupower frequency-set -f "$FREQ" > /dev/null || ESTATUS=1
+elif test -n "${GOVERNOR}${MIN_FREQ}${MAX_FREQ}"
+then
+    cpupower frequency-set \
+      ${GOVERNOR:+ -g "$GOVERNOR"} \
+      ${MIN_FREQ:+ -d "$MIN_FREQ"} ${MAX_FREQ:+ -u "$MAX_FREQ"} \
+      > /dev/null || ESTATUS=1
+fi
+
+# apply CPU policy options
+if test -n "$PERF_BIAS"
+then
+    cpupower set -b "$PERF_BIAS" > /dev/null || ESTATUS=1
+fi
+
+exit $ESTATUS