selftest: cpufreq: Add support for cpufreq tests

This patch adds supports for basic cpufreq tests, which can be performed
independent of any platform.

It does basic tests for now, like
- reading all cpufreq files
- trying to update them
- switching frequencies
- switching governors

This can be extended to have more specific tests later on.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/Makefile

@@ -1,6 +1,7 @@
 TARGETS =  bpf
 TARGETS += breakpoints
 TARGETS += capabilities
+TARGETS += cpufreq
 TARGETS += cpu-hotplug
 TARGETS += efivarfs
 TARGETS += exec

tools/testing/selftests/cpufreq/Makefile

@@ -0,0 +1,8 @@
+all:
+
+TEST_PROGS := main.sh
+TEST_FILES := cpu.sh cpufreq.sh governor.sh
+
+include ../lib.mk
+
+clean:

tools/testing/selftests/cpufreq/cpu.sh

@@ -0,0 +1,84 @@
+#!/bin/bash
+#
+# CPU helpers
+
+# protect against multiple inclusion
+if [ $FILE_CPU ]; then
+	return 0
+else
+	FILE_CPU=DONE
+fi
+
+source cpufreq.sh
+
+for_each_cpu()
+{
+	cpus=$(ls $CPUROOT | grep "cpu[0-9].*")
+	for cpu in $cpus; do
+		$@ $cpu
+	done
+}
+
+for_each_non_boot_cpu()
+{
+	cpus=$(ls $CPUROOT | grep "cpu[1-9].*")
+	for cpu in $cpus; do
+		$@ $cpu
+	done
+}
+
+#$1: cpu
+offline_cpu()
+{
+	printf "Offline $1\n"
+	echo 0 > $CPUROOT/$1/online
+}
+
+#$1: cpu
+online_cpu()
+{
+	printf "Online $1\n"
+	echo 1 > $CPUROOT/$1/online
+}
+
+#$1: cpu
+reboot_cpu()
+{
+	offline_cpu $1
+	online_cpu $1
+}
+
+# Reboot CPUs
+# param: number of times we want to run the loop
+reboot_cpus()
+{
+	printf "** Test: Running ${FUNCNAME[0]} for $1 loops **\n\n"
+
+	for i in `seq 1 $1`; do
+		for_each_non_boot_cpu offline_cpu
+		for_each_non_boot_cpu online_cpu
+		printf "\n"
+	done
+
+	printf "\n%s\n\n" "------------------------------------------------"
+}
+
+# Prints warning for all CPUs with missing cpufreq directory
+print_unmanaged_cpus()
+{
+	for_each_cpu cpu_should_have_cpufreq_directory
+}
+
+# Counts CPUs with cpufreq directories
+count_cpufreq_managed_cpus()
+{
+	count=0;
+
+	for cpu in `ls $CPUROOT | grep "cpu[0-9].*"`; do
+		if [ -d $CPUROOT/$cpu/cpufreq ]; then
+			let count=count+1;
+		fi
+	done
+
+	echo $count;
+}

tools/testing/selftests/cpufreq/cpufreq.sh

@@ -0,0 +1,201 @@
+#!/bin/bash
+
+# protect against multiple inclusion
+if [ $FILE_CPUFREQ ]; then
+	return 0
+else
+	FILE_CPUFREQ=DONE
+fi
+
+source cpu.sh
+
+
+# $1: cpu
+cpu_should_have_cpufreq_directory()
+{
+	if [ ! -d $CPUROOT/$1/cpufreq ]; then
+		printf "Warning: No cpufreq directory present for $1\n"
+	fi
+}
+
+cpu_should_not_have_cpufreq_directory()
+{
+	if [ -d $CPUROOT/$1/cpufreq ]; then
+		printf "Warning: cpufreq directory present for $1\n"
+	fi
+}
+
+for_each_policy()
+{
+	policies=$(ls $CPUFREQROOT| grep "policy[0-9].*")
+	for policy in $policies; do
+		$@ $policy
+	done
+}
+
+for_each_policy_concurrent()
+{
+	policies=$(ls $CPUFREQROOT| grep "policy[0-9].*")
+	for policy in $policies; do
+		$@ $policy &
+	done
+}
+
+# $1: Path
+read_cpufreq_files_in_dir()
+{
+	local files=`ls $1`
+
+	printf "Printing directory: $1\n\n"
+
+	for file in $files; do
+		if [ -f $1/$file ]; then
+			printf "$file:"
+			cat $1/$file
+		else
+			printf "\n"
+			read_cpufreq_files_in_dir "$1/$file"
+		fi
+	done
+	printf "\n"
+}
+
+
+read_all_cpufreq_files()
+{
+	printf "** Test: Running ${FUNCNAME[0]} **\n\n"
+
+	read_cpufreq_files_in_dir $CPUFREQROOT
+
+	printf "%s\n\n" "------------------------------------------------"
+}
+
+
+# UPDATE CPUFREQ FILES
+
+# $1: directory path
+update_cpufreq_files_in_dir()
+{
+	local files=`ls $1`
+
+	printf "Updating directory: $1\n\n"
+
+	for file in $files; do
+		if [ -f $1/$file ]; then
+			# file is writable ?
+			local wfile=$(ls -l $1/$file | awk '$1 ~ /^.*w.*/ { print $NF; }')
+
+			if [ ! -z $wfile ]; then
+				# scaling_setspeed is a special file and we
+				# should skip updating it
+				if [ $file != "scaling_setspeed" ]; then
+					local val=$(cat $1/$file)
+					printf "Writing $val to: $file\n"
+					echo $val > $1/$file
+				fi
+			fi
+		else
+			printf "\n"
+			update_cpufreq_files_in_dir "$1/$file"
+		fi
+	done
+
+	printf "\n"
+}
+
+# Update all writable files with their existing values
+update_all_cpufreq_files()
+{
+	printf "** Test: Running ${FUNCNAME[0]} **\n\n"
+
+	update_cpufreq_files_in_dir $CPUFREQROOT
+
+	printf "%s\n\n" "------------------------------------------------"
+}
+
+
+# CHANGE CPU FREQUENCIES
+
+# $1: policy
+find_current_freq()
+{
+	cat $CPUFREQROOT/$1/scaling_cur_freq
+}
+
+# $1: policy
+# $2: frequency
+set_cpu_frequency()
+{
+	printf "Change frequency for $1 to $2\n"
+	echo $2 > $CPUFREQROOT/$1/scaling_setspeed
+}
+
+# $1: policy
+test_all_frequencies()
+{
+	local filepath="$CPUFREQROOT/$1"
+
+	backup_governor $1
+
+	local found=$(switch_governor $1 "userspace")
+	if [ $found = 1 ]; then
+		printf "${FUNCNAME[0]}: userspace governor not available for: $1\n"
+		return;
+	fi
+
+	printf "Switched governor for $1 to userspace\n\n"
+
+	local freqs=$(cat $filepath/scaling_available_frequencies)
+	printf "Available frequencies for $1: $freqs\n\n"
+
+	# Set all frequencies one-by-one
+	for freq in $freqs; do
+		set_cpu_frequency $1 $freq
+	done
+
+	printf "\n"
+
+	restore_governor $1
+}
+
+# $1: loop count
+shuffle_frequency_for_all_cpus()
+{
+	printf "** Test: Running ${FUNCNAME[0]} for $1 loops **\n\n"
+
+	for i in `seq 1 $1`; do
+		for_each_policy test_all_frequencies
+	done
+	printf "\n%s\n\n" "------------------------------------------------"
+}
+
+# Basic cpufreq tests
+cpufreq_basic_tests()
+{
+	printf "*** RUNNING CPUFREQ SANITY TESTS ***\n"
+	printf "====================================\n\n"
+
+	count=$(count_cpufreq_managed_cpus)
+	if [ $count = 0 ]; then
+		printf "No cpu is managed by cpufreq core, exiting\n"
+		exit;
+	else
+		printf "CPUFreq manages: $count CPUs\n\n"
+	fi
+
+	# Detect & print which CPUs are not managed by cpufreq
+	print_unmanaged_cpus
+
+	# read/update all cpufreq files
+	read_all_cpufreq_files
+	update_all_cpufreq_files
+
+	# hotplug cpus
+	reboot_cpus 5
+
+	# Test all frequencies
+	shuffle_frequency_for_all_cpus 2
+
+	# Test all governors
+	shuffle_governors_for_all_cpus 1
+}