1 files changed, 117 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/va_high_addr_switch.sh b/tools/testing/selftests/mm/va_high_addr_switch.sh
new file mode 100755
index 000000000000..a7d4b02b21dd
--- /dev/null
+++ b/tools/testing/selftests/mm/va_high_addr_switch.sh
@@ -0,0 +1,117 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2022 Adam Sindelar (Meta) <adam@wowsignal.io>
+#
+# This is a test for mmap behavior with 5-level paging. This script wraps the
+# real test to check that the kernel is configured to support at least 5
+# pagetable levels.
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+orig_nr_hugepages=0
+
+skip()
+{
+	echo "$1"
+	exit $ksft_skip
+}
+
+check_supported_x86_64()
+{
+	local config="/proc/config.gz"
+	[[ -f "${config}" ]] || config="/boot/config-$(uname -r)"
+	[[ -f "${config}" ]] || skip "Cannot find kernel config in /proc or /boot"
+
+	# gzip -dcfq automatically handles both compressed and plaintext input.
+	# See man 1 gzip under '-f'.
+	local pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2)
+
+	local cpu_supports_pl5=$(awk '/^flags/ {if (/la57/) {print 0;}
+		else {print 1}; exit}' /proc/cpuinfo 2>/dev/null)
+
+	if [[ "${pg_table_levels}" -lt 5 ]]; then
+		skip "$0: PGTABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"
+	elif [[ "${cpu_supports_pl5}" -ne 0 ]]; then
+		skip "$0: CPU does not have the necessary la57 flag to support page table level 5"
+	fi
+}
+
+check_supported_ppc64()
+{
+	local config="/proc/config.gz"
+	[[ -f "${config}" ]] || config="/boot/config-$(uname -r)"
+	[[ -f "${config}" ]] || skip "Cannot find kernel config in /proc or /boot"
+
+	local pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2)
+	if [[ "${pg_table_levels}" -lt 5 ]]; then
+		skip "$0: PGTABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"
+	fi
+
+	local mmu_support=$(grep -m1 "mmu" /proc/cpuinfo | awk '{print $3}')
+	if [[ "$mmu_support" != "radix" ]]; then
+		skip "$0: System does not use Radix MMU, required for 5-level paging"
+	fi
+
+	local hugepages_total=$(awk '/HugePages_Total/ {print $2}' /proc/meminfo)
+	if [[ "${hugepages_total}" -eq 0 ]]; then
+		skip "$0: HugePages are not enabled, required for some tests"
+	fi
+}
+
+check_test_requirements()
+{
+	# The test supports x86_64 and powerpc64. We currently have no useful
+	# eligibility check for powerpc64, and the test itself will reject other
+	# architectures.
+	case `uname -m` in
+		"x86_64")
+			check_supported_x86_64
+		;;
+		"ppc64le"|"ppc64")
+			check_supported_ppc64
+		;;
+		*)
+			return 0
+		;;
+	esac
+}
+
+save_nr_hugepages()
+{
+	orig_nr_hugepages=$(cat /proc/sys/vm/nr_hugepages)
+}
+
+restore_nr_hugepages()
+{
+	echo "$orig_nr_hugepages" > /proc/sys/vm/nr_hugepages
+}
+
+setup_nr_hugepages()
+{
+	local needpgs=$1
+	while read -r name size unit; do
+		if [ "$name" = "HugePages_Free:" ]; then
+			freepgs="$size"
+			break
+		fi
+	done < /proc/meminfo
+	if [ "$freepgs" -ge "$needpgs" ]; then
+		return
+	fi
+	local hpgs=$((orig_nr_hugepages + needpgs))
+	echo $hpgs > /proc/sys/vm/nr_hugepages
+
+	local nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
+	if [ "$nr_hugepgs" != "$hpgs" ]; then
+		restore_nr_hugepages
+		skip "$0: no enough hugepages for testing"
+	fi
+}
+
+check_test_requirements
+save_nr_hugepages
+# 4 keep_mapped pages, and one for tmp usage
+setup_nr_hugepages 5
+./va_high_addr_switch --run-hugetlb
+restore_nr_hugepages