va_high_addr_switch.sh

  1#!/bin/bash
  2# SPDX-License-Identifier: GPL-2.0
  3#
  4# Copyright (C) 2022 Adam Sindelar (Meta) <adam@wowsignal.io>
  5#
  6# This is a test for mmap behavior with 5-level paging. This script wraps the
  7# real test to check that the kernel is configured to support at least 5
  8# pagetable levels.
  9
 10# Kselftest framework requirement - SKIP code is 4.
 11ksft_skip=4
 12orig_nr_hugepages=0
 13
 14skip()
 15{
 16	echo "$1"
 17	exit $ksft_skip
 18}
 19
 20check_supported_x86_64()
 21{
 22	local config="/proc/config.gz"
 23	[[ -f "${config}" ]] || config="/boot/config-$(uname -r)"
 24	[[ -f "${config}" ]] || skip "Cannot find kernel config in /proc or /boot"
 25
 26	# gzip -dcfq automatically handles both compressed and plaintext input.
 27	# See man 1 gzip under '-f'.
 28	local pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2)
 29
 30	local cpu_supports_pl5=$(awk '/^flags/ {if (/la57/) {print 0;}
 31		else {print 1}; exit}' /proc/cpuinfo 2>/dev/null)
 32
 33	if [[ "${pg_table_levels}" -lt 5 ]]; then
 34		skip "$0: PGTABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"
 35	elif [[ "${cpu_supports_pl5}" -ne 0 ]]; then
 36		skip "$0: CPU does not have the necessary la57 flag to support page table level 5"
 37	fi
 38}
 39
 40check_supported_ppc64()
 41{
 42	local config="/proc/config.gz"
 43	[[ -f "${config}" ]] || config="/boot/config-$(uname -r)"
 44	[[ -f "${config}" ]] || skip "Cannot find kernel config in /proc or /boot"
 45
 46	local pg_table_levels=$(gzip -dcfq "${config}" | grep PGTABLE_LEVELS | cut -d'=' -f 2)
 47	if [[ "${pg_table_levels}" -lt 5 ]]; then
 48		skip "$0: PGTABLE_LEVELS=${pg_table_levels}, must be >= 5 to run this test"
 49	fi
 50
 51	local mmu_support=$(grep -m1 "mmu" /proc/cpuinfo | awk '{print $3}')
 52	if [[ "$mmu_support" != "radix" ]]; then
 53		skip "$0: System does not use Radix MMU, required for 5-level paging"
 54	fi
 55
 56	local hugepages_total=$(awk '/HugePages_Total/ {print $2}' /proc/meminfo)
 57	if [[ "${hugepages_total}" -eq 0 ]]; then
 58		skip "$0: HugePages are not enabled, required for some tests"
 59	fi
 60}
 61
 62check_test_requirements()
 63{
 64	# The test supports x86_64 and powerpc64. We currently have no useful
 65	# eligibility check for powerpc64, and the test itself will reject other
 66	# architectures.
 67	case `uname -m` in
 68		"x86_64")
 69			check_supported_x86_64
 70		;;
 71		"ppc64le"|"ppc64")
 72			check_supported_ppc64
 73		;;
 74		*)
 75			return 0
 76		;;
 77	esac
 78}
 79
 80save_nr_hugepages()
 81{
 82	orig_nr_hugepages=$(cat /proc/sys/vm/nr_hugepages)
 83}
 84
 85restore_nr_hugepages()
 86{
 87	echo "$orig_nr_hugepages" > /proc/sys/vm/nr_hugepages
 88}
 89
 90setup_nr_hugepages()
 91{
 92	local needpgs=$1
 93	while read -r name size unit; do
 94		if [ "$name" = "HugePages_Free:" ]; then
 95			freepgs="$size"
 96			break
 97		fi
 98	done < /proc/meminfo
 99	if [ "$freepgs" -ge "$needpgs" ]; then
100		return
101	fi
102	local hpgs=$((orig_nr_hugepages + needpgs))
103	echo $hpgs > /proc/sys/vm/nr_hugepages
104
105	local nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
106	if [ "$nr_hugepgs" != "$hpgs" ]; then
107		restore_nr_hugepages
108		skip "$0: no enough hugepages for testing"
109	fi
110}
111
112check_test_requirements
113save_nr_hugepages
114# 4 keep_mapped pages, and one for tmp usage
115setup_nr_hugepages 5
116./va_high_addr_switch --run-hugetlb
117restore_nr_hugepages