s390/syscalls: add syscalltbl script

Introduce the syscalltbl script to read the system call table and
generate respective uapi unistd.h header files.  Also it generates
the contents syscalls.S - the real system call table - which is
included by arch/s390/kernel/entry.S.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/syscalls/syscalltbl

@@ -0,0 +1,232 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# Generate system call table and header files
+#
+# Copyright IBM Corp. 2018
+# Author(s):  Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
+
+#
+# File path to the system call table definition.
+# You can set the path with the -i option.  If omitted,
+# system call table definitions are read from standard input.
+#
+SYSCALL_TBL=""
+
+
+create_syscall_table_entries()
+{
+	local nr abi name entry64 entry32 _ignore
+	local temp=$(mktemp ${TMPDIR:-/tmp}/syscalltbl-common.XXXXXXXXX)
+
+	(
+	#
+	# Initialize with 0 to create an NI_SYSCALL for 0
+	#
+	local prev_nr=0 prev_32=sys_ni_syscall prev_64=sys_ni_syscall
+	while read nr abi name entry64 entry32 _ignore; do
+		test x$entry32 = x- && entry32=sys_ni_syscall
+		test x$entry64 = x- && entry64=sys_ni_syscall
+
+		if test $prev_nr -eq $nr; then
+			#
+			# Same syscall but different ABI, just update
+			# the respective entry point
+			#
+			case $abi in
+			32)
+				prev_32=$entry32
+			;;
+			64)
+				prev_64=$entry64
+			;;
+			esac
+			continue;
+		else
+			printf "%d\t%s\t%s\n" $prev_nr $prev_64 $prev_32
+		fi
+
+		prev_nr=$nr
+		prev_64=$entry64
+		prev_32=$entry32
+	done
+	printf "%d\t%s\t%s\n" $prev_nr $prev_64 $prev_32
+	) >> $temp
+
+	#
+	# Check for duplicate syscall numbers
+	#
+	if ! cat $temp |cut -f1 |uniq -d 2>&1; then
+		echo "Error: generated system call table contains duplicate entries: $temp" >&2
+		exit 1
+	fi
+
+	#
+	# Generate syscall table
+	#
+	prev_nr=0
+	while read nr entry64 entry32; do
+		while test $prev_nr -lt $((nr - 1)); do
+			printf "NI_SYSCALL\n"
+			prev_nr=$((prev_nr + 1))
+		done
+		if test x$entry64 = xsys_ni_syscall &&
+		   test x$entry32 = xsys_ni_syscall; then
+			printf "NI_SYSCALL\n"
+		else
+			printf "SYSCALL(%s,%s)\n" $entry64 $entry32
+		fi
+		prev_nr=$nr
+	done < $temp
+	rm $temp
+}
+
+generate_syscall_table()
+{
+	cat <<-EoHEADER
+	/* SPDX-License-Identifier: GPL-2.0 */
+	/*
+	 * Definitions for sys_call_table, each line represents an
+	 * entry in the table in the form
+	 * SYSCALL(64 bit syscall, 31 bit emulated syscall)
+	 *
+	 * This file is meant to be included from entry.S.
+	 */
+
+	#define NI_SYSCALL SYSCALL(sys_ni_syscall,sys_ni_syscall)
+
+EoHEADER
+	grep -Ev '^(#|[[:blank:]]*$)' $SYSCALL_TBL	\
+		|sort -k1 -n				\
+		|create_syscall_table_entries
+}
+
+create_header_defines()
+{
+	local nr abi name _ignore
+
+	while read nr abi name _ignore; do
+		printf "#define __NR_%s %d\n" $name $nr
+	done
+}
+
+normalize_fileguard()
+{
+	local fileguard="$1"
+
+	echo "$1" |tr '[[:lower:]]' '[[:upper:]]' \
+		  |sed -e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g'
+}
+
+generate_syscall_header()
+{
+	local abis=$(echo "($1)" | tr ',' '|')
+	local filename="$2"
+	local fileguard suffix
+
+	if test "$filename"; then
+		fileguard=$(normalize_fileguard "__UAPI_ASM_S390_$2")
+	else
+		case "$abis" in
+		*64*) suffix=64 ;;
+		*32*) suffix=32 ;;
+		esac
+		fileguard=$(normalize_fileguard "__UAPI_ASM_S390_SYSCALLS_$suffix")
+	fi
+
+	cat <<-EoHEADER
+	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+	#ifndef ${fileguard}
+	#define ${fileguard}
+
+EoHEADER
+
+	grep -E "^[[:digit:]]+[[:space:]]+${abis}" $SYSCALL_TBL	\
+		|sort -k1 -n					\
+		|create_header_defines
+
+	cat <<-EoFOOTER
+
+	#endif /* ${fileguard} */
+EoFOOTER
+}
+
+__max_syscall_nr()
+{
+	local abis=$(echo "($1)" | tr ',' '|')
+
+	grep -E "^[[:digit:]]+[[:space:]]+${abis}" $SYSCALL_TBL	 \
+		|sed -ne 's/^\([[:digit:]]*\)[[:space:]].*/\1/p' \
+		|sort -n					 \
+		|tail -1
+}
+
+
+generate_syscall_nr()
+{
+	local abis="$1"
+	local max_syscall_nr num_syscalls
+
+	max_syscall_nr=$(__max_syscall_nr "$abis")
+	num_syscalls=$((max_syscall_nr + 1))
+
+	cat <<-EoHEADER
+	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+	#ifndef __ASM_S390_SYSCALLS_NR
+	#define __ASM_S390_SYSCALLS_NR
+
+	#define NR_syscalls ${num_syscalls}
+
+	#endif /* __ASM_S390_SYSCALLS_NR */
+EoHEADER
+}
+
+
+#
+# Parse command line arguments
+#
+do_syscall_header=""
+do_syscall_table=""
+do_syscall_nr=""
+output_file=""
+abi_list="common,64"
+filename=""
+while getopts ":HNSXi:a:f:" arg; do
+	case $arg in
+	a)
+		abi_list="$OPTARG"
+		;;
+	i)
+		SYSCALL_TBL="$OPTARG"
+		;;
+	f)
+		filename=${OPTARG##*/}
+		;;
+	H)
+		do_syscall_header=1
+		;;
+	N)
+		do_syscall_nr=1
+		;;
+	S)
+		do_syscall_table=1
+		;;
+	X)
+		set -x
+		;;
+	:)
+		echo "Missing argument for -$OPTARG" >&2
+		exit 1
+	;;
+	\?)
+		echo "Invalid option specified" >&2
+		exit 1
+	;;
+	esac
+done
+
+test "$do_syscall_header" && generate_syscall_header "$abi_list" "$filename"
+test "$do_syscall_table" && generate_syscall_table
+test "$do_syscall_nr" && generate_syscall_nr "$abi_list"
+
+exit 0