kselftest/arm64: sme: Add SME support to vlset

The Scalable Matrix Extenions (SME) introduces additional register state
with configurable vector lengths, similar to SVE but configured separately.
Extend vlset to support configuring this state with a --sme or -s command
line option.

Signed-off-by: Mark Brown <[e-mail]>
Reviewed-by: Shuah Khan <[e-mail]>
Acked-by: Catalin Marinas <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Catalin Marinas <[e-mail]>

tools/testing/selftests/arm64/fp/vlset.c

···
 static int no_inherit = 0;
 static int force = 0;
 static unsigned long vl;
+static int set_ctl = PR_SVE_SET_VL;
+static int get_ctl = PR_SVE_GET_VL;
 
 static const struct option options[] = {
 	{ "force",	no_argument, NULL, 'f' },
 	{ "inherit",	no_argument, NULL, 'i' },
 	{ "max",	no_argument, NULL, 'M' },
 	{ "no-inherit",	no_argument, &no_inherit, 1 },
+	{ "sme",	no_argument, NULL, 's' },
 	{ "help",	no_argument, NULL, '?' },
 	{}
 };
···
 		case 'M':	vl = SVE_VL_MAX; break;
 		case 'f':	force = 1; break;
 		case 'i':	inherit = 1; break;
+		case 's':	set_ctl = PR_SME_SET_VL;
+				get_ctl = PR_SME_GET_VL;
+				break;
 		case 0:		break;
 		default:	goto error;
 		}
···
 	if (inherit)
 		flags |= PR_SVE_VL_INHERIT;
 
-	t = prctl(PR_SVE_SET_VL, vl | flags);
+	t = prctl(set_ctl, vl | flags);
 	if (t < 0) {
 		fprintf(stderr, "%s: PR_SVE_SET_VL: %s\n",
 			program_name, strerror(errno));
 		goto error;
 	}
 
-	t = prctl(PR_SVE_GET_VL);
+	t = prctl(get_ctl);
 	if (t == -1) {
 		fprintf(stderr, "%s: PR_SVE_GET_VL: %s\n",
 			program_name, strerror(errno));