v4.19.13 snapshot.
diff --git a/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
new file mode 100755
index 0000000..bab13dd
--- /dev/null
+++ b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
@@ -0,0 +1,286 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+SYSFS=
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+prerequisite()
+{
+ msg="skip all tests:"
+
+ if [ $UID != 0 ]; then
+ echo $msg must be run as root >&2
+ exit $ksft_skip
+ fi
+
+ taskset -p 01 $$
+
+ SYSFS=`mount -t sysfs | head -1 | awk '{ print $3 }'`
+
+ if [ ! -d "$SYSFS" ]; then
+ echo $msg sysfs is not mounted >&2
+ exit $ksft_skip
+ fi
+
+ if ! ls $SYSFS/devices/system/cpu/cpu* > /dev/null 2>&1; then
+ echo $msg cpu hotplug is not supported >&2
+ exit $ksft_skip
+ fi
+
+ echo "CPU online/offline summary:"
+ online_cpus=`cat $SYSFS/devices/system/cpu/online`
+ online_max=${online_cpus##*-}
+
+ if [[ "$online_cpus" = "$online_max" ]]; then
+ echo "$msg: since there is only one cpu: $online_cpus"
+ exit $ksft_skip
+ fi
+
+ echo -e "\t Cpus in online state: $online_cpus"
+
+ offline_cpus=`cat $SYSFS/devices/system/cpu/offline`
+ if [[ "a$offline_cpus" = "a" ]]; then
+ offline_cpus=0
+ else
+ offline_max=${offline_cpus##*-}
+ fi
+ echo -e "\t Cpus in offline state: $offline_cpus"
+}
+
+#
+# list all hot-pluggable CPUs
+#
+hotpluggable_cpus()
+{
+ local state=${1:-.\*}
+
+ for cpu in $SYSFS/devices/system/cpu/cpu*; do
+ if [ -f $cpu/online ] && grep -q $state $cpu/online; then
+ echo ${cpu##/*/cpu}
+ fi
+ done
+}
+
+hotplaggable_offline_cpus()
+{
+ hotpluggable_cpus 0
+}
+
+hotpluggable_online_cpus()
+{
+ hotpluggable_cpus 1
+}
+
+cpu_is_online()
+{
+ grep -q 1 $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+cpu_is_offline()
+{
+ grep -q 0 $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+online_cpu()
+{
+ echo 1 > $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+offline_cpu()
+{
+ echo 0 > $SYSFS/devices/system/cpu/cpu$1/online
+}
+
+online_cpu_expect_success()
+{
+ local cpu=$1
+
+ if ! online_cpu $cpu; then
+ echo $FUNCNAME $cpu: unexpected fail >&2
+ exit 1
+ elif ! cpu_is_online $cpu; then
+ echo $FUNCNAME $cpu: unexpected offline >&2
+ exit 1
+ fi
+}
+
+online_cpu_expect_fail()
+{
+ local cpu=$1
+
+ if online_cpu $cpu 2> /dev/null; then
+ echo $FUNCNAME $cpu: unexpected success >&2
+ exit 1
+ elif ! cpu_is_offline $cpu; then
+ echo $FUNCNAME $cpu: unexpected online >&2
+ exit 1
+ fi
+}
+
+offline_cpu_expect_success()
+{
+ local cpu=$1
+
+ if ! offline_cpu $cpu; then
+ echo $FUNCNAME $cpu: unexpected fail >&2
+ exit 1
+ elif ! cpu_is_offline $cpu; then
+ echo $FUNCNAME $cpu: unexpected offline >&2
+ exit 1
+ fi
+}
+
+offline_cpu_expect_fail()
+{
+ local cpu=$1
+
+ if offline_cpu $cpu 2> /dev/null; then
+ echo $FUNCNAME $cpu: unexpected success >&2
+ exit 1
+ elif ! cpu_is_online $cpu; then
+ echo $FUNCNAME $cpu: unexpected offline >&2
+ exit 1
+ fi
+}
+
+error=-12
+allcpus=0
+priority=0
+online_cpus=0
+online_max=0
+offline_cpus=0
+offline_max=0
+
+while getopts e:ahp: opt; do
+ case $opt in
+ e)
+ error=$OPTARG
+ ;;
+ a)
+ allcpus=1
+ ;;
+ h)
+ echo "Usage $0 [ -a ] [ -e errno ] [ -p notifier-priority ]"
+ echo -e "\t default offline one cpu"
+ echo -e "\t run with -a option to offline all cpus"
+ exit
+ ;;
+ p)
+ priority=$OPTARG
+ ;;
+ esac
+done
+
+if ! [ "$error" -ge -4095 -a "$error" -lt 0 ]; then
+ echo "error code must be -4095 <= errno < 0" >&2
+ exit 1
+fi
+
+prerequisite
+
+#
+# Safe test (default) - offline and online one cpu
+#
+if [ $allcpus -eq 0 ]; then
+ echo "Limited scope test: one hotplug cpu"
+ echo -e "\t (leaves cpu in the original state):"
+ echo -e "\t online to offline to online: cpu $online_max"
+ offline_cpu_expect_success $online_max
+ online_cpu_expect_success $online_max
+
+ if [[ $offline_cpus -gt 0 ]]; then
+ echo -e "\t offline to online to offline: cpu $offline_max"
+ online_cpu_expect_success $offline_max
+ offline_cpu_expect_success $offline_max
+ fi
+ exit 0
+else
+ echo "Full scope test: all hotplug cpus"
+ echo -e "\t online all offline cpus"
+ echo -e "\t offline all online cpus"
+ echo -e "\t online all offline cpus"
+fi
+
+#
+# Online all hot-pluggable CPUs
+#
+for cpu in `hotplaggable_offline_cpus`; do
+ online_cpu_expect_success $cpu
+done
+
+#
+# Offline all hot-pluggable CPUs
+#
+for cpu in `hotpluggable_online_cpus`; do
+ offline_cpu_expect_success $cpu
+done
+
+#
+# Online all hot-pluggable CPUs again
+#
+for cpu in `hotplaggable_offline_cpus`; do
+ online_cpu_expect_success $cpu
+done
+
+#
+# Test with cpu notifier error injection
+#
+
+DEBUGFS=`mount -t debugfs | head -1 | awk '{ print $3 }'`
+NOTIFIER_ERR_INJECT_DIR=$DEBUGFS/notifier-error-inject/cpu
+
+prerequisite_extra()
+{
+ msg="skip extra tests:"
+
+ /sbin/modprobe -q -r cpu-notifier-error-inject
+ /sbin/modprobe -q cpu-notifier-error-inject priority=$priority
+
+ if [ ! -d "$DEBUGFS" ]; then
+ echo $msg debugfs is not mounted >&2
+ exit $ksft_skip
+ fi
+
+ if [ ! -d $NOTIFIER_ERR_INJECT_DIR ]; then
+ echo $msg cpu-notifier-error-inject module is not available >&2
+ exit $ksft_skip
+ fi
+}
+
+prerequisite_extra
+
+#
+# Offline all hot-pluggable CPUs
+#
+echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
+for cpu in `hotpluggable_online_cpus`; do
+ offline_cpu_expect_success $cpu
+done
+
+#
+# Test CPU hot-add error handling (offline => online)
+#
+echo $error > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_UP_PREPARE/error
+for cpu in `hotplaggable_offline_cpus`; do
+ online_cpu_expect_fail $cpu
+done
+
+#
+# Online all hot-pluggable CPUs
+#
+echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_UP_PREPARE/error
+for cpu in `hotplaggable_offline_cpus`; do
+ online_cpu_expect_success $cpu
+done
+
+#
+# Test CPU hot-remove error handling (online => offline)
+#
+echo $error > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
+for cpu in `hotpluggable_online_cpus`; do
+ offline_cpu_expect_fail $cpu
+done
+
+echo 0 > $NOTIFIER_ERR_INJECT_DIR/actions/CPU_DOWN_PREPARE/error
+/sbin/modprobe -q -r cpu-notifier-error-inject