selftests/xsk: display command line options with -h

Add the -h option to display all available command line options
available for test_xsk.sh and xskxceiver.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230914084900.492-11-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/test_xsk.sh

@@ -82,12 +82,15 @@
 #
 # Run a specific test from the test suite
 #   sudo ./test_xsk.sh -t TEST_NAME
+#
+# Display the available command line options
+#   ./test_xsk.sh -h
 
 . xsk_prereqs.sh
 
 ETH=""
 
-while getopts "vi:dm:lt:" flag
+while getopts "vi:dm:lt:h" flag
 do
 	case "${flag}" in
 		v) verbose=1;;
@@ -96,6 +99,7 @@ do
 		m) MODE=${OPTARG};;
 		l) list=1;;
 		t) TEST=${OPTARG};;
+		h) help=1;;
 	esac
 done
 
@@ -148,6 +152,11 @@ if [[ $list -eq 1 ]]; then
         exit
 fi
 
+if [[ $help -eq 1 ]]; then
+	./${XSKOBJ}
+        exit
+fi
+
 if [ ! -z $ETH ]; then
 	VETH0=${ETH}
 	VETH1=${ETH}

tools/testing/selftests/bpf/xskxceiver.c

@@ -318,6 +318,7 @@ static struct option long_options[] = {
 	{"mode", required_argument, 0, 'm'},
 	{"list", no_argument, 0, 'l'},
 	{"test", required_argument, 0, 't'},
+	{"help", no_argument, 0, 'h'},
 	{0, 0, 0, 0}
 };
 
@@ -331,7 +332,8 @@ static void print_usage(char **argv)
 		"  -b, --busy-poll      Enable busy poll\n"
 		"  -m, --mode           Run only mode skb, drv, or zc\n"
 		"  -l, --list           List all available tests\n"
-		"  -t, --test           Run a specific test. Enter number from -l option.\n";
+		"  -t, --test           Run a specific test. Enter number from -l option.\n"
+		"  -h, --help           Display this help and exit\n";
 
 	ksft_print_msg(str, basename(argv[0]));
 	ksft_exit_xfail();
@@ -402,6 +404,7 @@ static void parse_command_line(struct ifobject *ifobj_tx, struct ifobject *ifobj
 			if (errno)
 				print_usage(argv);
 			break;
+		case 'h':
 		default:
 			print_usage(argv);
 		}