diff --git a/common/rc b/common/rc
index 78a2101..73ac79c 100644
--- a/common/rc
+++ b/common/rc
@@ -3151,6 +3151,51 @@ _require_chattr()
 	rm -f $TEST_DIR/syscalltest.out
 }
 
+# Require test/scratch device nvdimm and having specific
+# arttibute key/value we need.
+#
+# This is designed to get attr values of nvdimm persistent
+# memory device, by searching sysfs.
+#
+# Other non-nvdimm or non-persistent-memory devices would
+# fail this helper anyway.
+#
+# So, ONLY use this helper when you REALLY need nvdimm and
+# specific attr on it.
+#
+_require_pmem_key_value()
+{
+	local dev=${1#/dev/}
+	local key=$2
+	local value=$3
+	local region index keyfile dev_value
+
+	# find a filename string contains the region of dev, eg:
+	#  /sys/devices/platform/e820_pmem/ndbus0/region1/\
+	#  namespace1.0/block/pmem1
+	#
+	region=$(find /sys/ | grep $dev | grep region | head -1)
+	[ -z "$region" ] && \
+	  _notrun "requires persistent memory $dev $key $value"
+
+	# get region number index
+	index=$(expr $region : .*region)
+
+	# find the file for the key, eg:
+	#  /sys/devices/platform/e820_pmem/ndbus0/region1/\
+	#  namespace1.0/mode
+	#
+	keyfile=$(find /sys/ | grep region${region:$index:2} \
+	  | grep namespace | grep $key)
+	[ -z "$keyfile" ] && \
+	  _notrun "requires persistent memory $dev $key $value"
+
+	# get the value and test
+	dev_value=$(cat $keyfile)
+	[ "$dev_value" != "$value" ] && \
+	  _notrun "requires $dev $key $value"
+}
+
 _get_total_inode()
 {
 	if [ -z "$1" ]; then
diff --git a/tests/generic/423 b/tests/generic/423
new file mode 100755
index 0000000..73c0b53
--- /dev/null
+++ b/tests/generic/423
@@ -0,0 +1,113 @@
+#! /bin/bash
+# FS QA Test 423
+#
+# mmap direct/buffered io from DAX to non-DAX mountpoints.
+# Split from generic/413, only do the DAX to non-DAX part.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Red Hat Inc.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+_supported_fs generic
+_supported_os Linux
+_require_test
+_require_scratch_dax
+_require_test_program "feature"
+_require_test_program "t_mmap_dio"
+_require_xfs_io_command "falloc"
+_require_pmem_key_value $SCRATCH_DEV "mode" "memory"
+
+prep_files()
+{
+	rm -f $SCRATCH_MNT/tf_{s,d}
+	rm -f $TEST_DIR/tf_{s,d}
+
+	$XFS_IO_PROG -f -c "falloc 0 $tsize" \
+		$SCRATCH_MNT/tf_{s,d} >> $seqres.full 2>&1
+	$XFS_IO_PROG -f -c "falloc 0 $tsize" \
+		$TEST_DIR/tf_{s,d} >> $seqres.full 2>&1
+}
+
+t_dax_to_nondax()
+{
+	prep_files
+	src/t_mmap_dio $SCRATCH_MNT/tf_s \
+		$TEST_DIR/tf_d $1 "dio dax to nondax"
+
+	prep_files
+	src/t_mmap_dio -b $SCRATCH_MNT/tf_s \
+		$TEST_DIR/tf_d $1 "buffered dax to nondax"
+}
+
+do_tests()
+{
+	# less than page size
+	t_dax_to_nondax 1024
+	# page size
+	t_dax_to_nondax `src/feature -s`
+	# bigger sizes, for PMD faults
+	t_dax_to_nondax $((16 * 1024 * 1024))
+	t_dax_to_nondax $((64 * 1024 * 1024))
+}
+
+# make fs 2Mb aligned for PMD fault testing
+mkfs_opts=""
+if [ "$FSTYP" == "ext4" ]; then
+	mkfs_opts="-E stride=512,stripe_width=1"
+elif [ "$FSTYP" == "xfs" ]; then
+	mkfs_opts="-d su=2m,sw=1"
+fi
+_scratch_mkfs "$mkfs_opts" > /dev/null 2>&1
+
+# mount SCRATCH_DEV with dax option, TEST_DEV not
+export MOUNT_OPTIONS=""
+export TEST_FS_MOUNT_OPTS=""
+_test_cycle_mount
+_fs_options $TEST_DEV | grep -qw "dax" && \
+	_notrun "we need $TEST_DEV mount without dax"
+_scratch_mount "-o dax"
+
+tsize=$((128 * 1024 * 1024))
+
+do_tests
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/generic/423.out b/tests/generic/423.out
new file mode 100644
index 0000000..22c4029
--- /dev/null
+++ b/tests/generic/423.out
@@ -0,0 +1,2 @@
+QA output created by 423
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index d747385..52553fa 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -425,3 +425,4 @@
 420 auto quick punch
 421 auto quick encrypt dangerous
 422 auto quick
+423 auto quick
