[PATCH v4 10/12] syscalls: Add an option for offsetting the common table

[André Almeida]

To better support architectures that doesn't share the same syscall
numbers, but have them in the same sequence, add an new option to offset
the common syscall table numbers by a value. This make it possible to reuse
the common syscall table for alpha.

Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
 scripts/syscallhdr.sh | 21 ++++++++++++++-------
 scripts/syscalltbl.sh | 17 ++++++++++++++---
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/scripts/syscallhdr.sh b/scripts/syscallhdr.sh
index 54e09d3e686c..0e095dac9db2 100755
--- a/scripts/syscallhdr.sh
+++ b/scripts/syscallhdr.sh
@@ -16,17 +16,18 @@
 set -e
 
 usage() {
-	echo >&2 "usage: $0 [--abis ABIS] [--emit-nr] [--offset OFFSET] [--prefix PREFIX] [--common-tbl PATH] INFILE OUTFILE" >&2
+	echo >&2 "usage: $0 [--abis ABIS] [--emit-nr] [--offset OFFSET] [--prefix PREFIX] [--common-tbl PATH] [--common-offset OFFSET] INFILE OUTFILE" >&2
 	echo >&2
 	echo >&2 "  INFILE    input syscall table"
 	echo >&2 "  OUTFILE   output header file"
 	echo >&2
 	echo >&2 "options:"
-	echo >&2 "  --abis ABIS        ABI(s) to handle (By default, all lines are handled)"
-	echo >&2 "  --emit-nr          Emit the macro of the number of syscalls (__NR_syscalls)"
-	echo >&2 "  --offset OFFSET    The offset of syscall numbers"
-	echo >&2 "  --prefix PREFIX    The prefix to the macro like __NR_<PREFIX><NAME>"
-	echo >&2 "  --common-tbl PATH  Use the common number table"
+	echo >&2 "  --abis ABIS             ABI(s) to handle (By default, all lines are handled)"
+	echo >&2 "  --emit-nr               Emit the macro of the number of syscalls (__NR_syscalls)"
+	echo >&2 "  --offset OFFSET         The offset of syscall numbers"
+	echo >&2 "  --prefix PREFIX         The prefix to the macro like __NR_<PREFIX><NAME>"
+	echo >&2 "  --common-tbl PATH       Use the common number table"
+	echo >&2 "  --common-offset OFFSET  Apply an offset for the numbers of the common table"
 	exit 1
 }
 
@@ -34,6 +35,7 @@ usage() {
 abis=
 emit_nr=
 offset=
+common_offset=
 prefix=
 common_tbl=
 common_tbl_path=
@@ -57,6 +59,9 @@ do
 		common_tbl=1
 		common_tbl_path=$2
 		shift 2;;
+	--common-offset)
+		common_offset=$2
+		shift 2;;
 	-*)
 		echo "$1: unknown option" >&2
 		usage;;
@@ -107,7 +112,7 @@ gen_hdr() {
 		max=$nr
 
 		if [ -n "$offset" ]; then
-			nr="($offset + $nr)"
+			nr=$((nr + offset))
 		fi
 
 		echo "#define __NR_$prefix$name $nr"
@@ -120,7 +125,9 @@ emit_start_guard > $outfile
 gen_hdr $infile >> $outfile
 
 if [ -n "$common_tbl" ]; then
+	offset=$common_offset
 	gen_hdr $common_tbl_path  >> "$outfile"
+	unset offset
 fi
 
 if [ -n "$emit_nr" ]; then
diff --git a/scripts/syscalltbl.sh b/scripts/syscalltbl.sh
index 91c135143b22..c00f848b5b66 100755
--- a/scripts/syscalltbl.sh
+++ b/scripts/syscalltbl.sh
@@ -16,14 +16,15 @@
 set -e
 
 usage() {
-	echo >&2 "usage: $0 [--abis ABIS] [--common-tbl PATH] INFILE OUTFILE" >&2
+	echo >&2 "usage: $0 [--abis ABIS] [--common-tbl PATH] [--common-offset OFFSET] INFILE OUTFILE" >&2
 	echo >&2
 	echo >&2 "  INFILE    input syscall table"
 	echo >&2 "  OUTFILE   output header file"
 	echo >&2
 	echo >&2 "options:"
-	echo >&2 "  --abis ABIS        ABI(s) to handle (By default, all lines are handled)"
-	echo >&2 "  --common-tbl PATH  Use the common syscall number table"
+	echo >&2 "  --abis ABIS             ABI(s) to handle (By default, all lines are handled)"
+	echo >&2 "  --common-tbl PATH       Use the common syscall number table"
+	echo >&2 "  --common-offset OFFSET  Apply an offset for the numbers of the common table"
 	exit 1
 }
 
@@ -31,6 +32,7 @@ usage() {
 abis=
 common_tbl=
 common_tbl_path=
+common_offset=
 
 while [ $# -gt 0 ]
 do
@@ -42,6 +44,9 @@ do
 		common_tbl=1
 		common_tbl_path=$2
 		shift 2;;
+	--common-offset)
+		common_offset=$2
+		shift 2;;
 	-*)
 		echo "$1: unknown option" >&2
 		usage;;
@@ -65,6 +70,10 @@ gen_tbl() {
 
 	while read nr abi name native compat noreturn; do
 
+		if [ -n "$offset" ]; then
+			nr=$((nr + offset))
+		fi
+
 		if [ $nxt -gt $nr ]; then
 			echo "error: $input: syscall table is not sorted or duplicates the same syscall number" >&2
 			exit 1
@@ -105,5 +114,7 @@ gen_tbl() {
 gen_tbl $infile  > "$outfile"
 
 if [ -n "$common_tbl" ]; then
+	offset=$common_offset
 	gen_tbl $common_tbl_path >> "$outfile"
+	unset offset
 fi

-- 
2.55.0