Both branches of the check return the same value, so the check has
no effect. Remove it and return the value directly.

This is the result of running the Coccinelle script from
scripts/coccinelle/misc/cond_return_no_effect.cocci.

Link: https://lore.kernel.org/linux-pm/20260723184538.3888637-36-ekffu200098@gmail.com/raw
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The patch ("cpupower: Add generic CPPC performance display") uses
roundf() but didn't include libm explicitly. This results in build
breaks in environments where its not automatically inlined.

Add libm to the cpupower makefile to correct this.

Fixes: 68f34fad760b ("cpupower: Add generic CPPC performance display")
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The kernel asserted frequency from scaling_cur_freq may not always match
the hardware reported frequency from cpuinfo_cur_freq.

Print both values when they are available, and only print the unavailable
message on x86 when the hardware frequency can't be read.

Link: https://lore.kernel.org/r/20260709221344.1919794-4-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Now that we have a generic CPPC printout, call it on !AMD
processors. If it fails to detect CPPC, or the registers don't look
reasonable then it will exit without printing anything.

Link: https://lore.kernel.org/r/20260709221344.1919794-3-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Arm64 machines, and possibly others, use the standard ACPI defined CPPC
infrastructure. cpupower has CPPC support, but it's largely written
around the intricacies of AMD processors, using platform MSRs to avoid
shortcomings in the specification.

Add a generic CPPC display that depends only on standardized fields. The
computed frequency values are best effort and rely on the FW providing
optional values that can be used to derive a meaningful frequency at a
given unique performance level.

Link: https://lore.kernel.org/r/20260709221344.1919794-2-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

extern char *optarg and extern int optind, opterr, optopt are
already declared by <getopt.h>, which is included at the top of
the file. Repeating extern declarations inside a function body
is misleading and unnecessary.

Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The cpupower-info(1) man page only mentions the short form of the
'--perf-bias' option in the synopsys, but the long form is not documented
and its effect is not explained.

cpupower-info.c:
     {"perf-bias", optional_argument, NULL, 'b'},

Signed-off-by: Roberto Ricci <io@r-ricci.it>
Link: https://lore.kernel.org/r/20260324223921.14317-5-io@r-ricci.it
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

`cpupower frequency-info` supports the '--boost' option since the program
was first added with commit 7fe2f6399a84 ("cpupowerutils - cpufrequtils
extended with quite some features"), but the man page lacks it.

'--epp' has been added with commit 5f567afc283f ("cpupower: Add support for
showing energy performance preference") but it has never been added to the
man page.

cpufreq-info.c:
	{"boost",	 no_argument,		 NULL,	 'b'},
	...
	{"epp",		 no_argument,		 NULL,	 'z'},

Signed-off-by: Roberto Ricci <io@r-ricci.it>
Link: https://lore.kernel.org/r/20260324223921.14317-4-io@r-ricci.it
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The cpupower-frequency-info(1) man page describes a '--perf' option.
Even though this form is accepted by the program, its proper name is
'--performance'.

cpufreq-info.c:
	{"performance", no_argument,	 NULL,	 'c'},

Signed-off-by: Roberto Ricci <io@r-ricci.it>
Link: https://lore.kernel.org/r/20260324223921.14317-3-io@r-ricci.it
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The cpupower-idle-info(1) man page describes '-f' as the short form of the
'--silent' option and '-e' as the short form of the '--proc' option.
But they are not correct:

$ cpupower idle-info -f
idle-info: invalid option -- 'f'
invalid or unknown argument
$ cpupower idle-info -e
idle-info: invalid option -- 'e'
invalid or unknown argument

The short form of '--silent' is actually '-s' and the short form of
'--proc' is actually '-o':

cpuidle-info.c:
	{"silent", no_argument, NULL, 's'},
	{"proc", no_argument, NULL, 'o'},

Signed-off-by: Roberto Ricci <io@r-ricci.it>
Link: https://lore.kernel.org/r/20260324223921.14317-2-io@r-ricci.it
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>