s390/syscalls: add syscalltbl script

#!/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