kselftest/arm64: Add GCS as a detected feature in the signal tests

In preparation for testing GCS related signal handling add it as a feature
we check for in the signal handling support code.

Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-30-222b78d87eee@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: broonie

tools/testing/selftests/arm64/signal/test_signals.h

@@ -35,6 +35,7 @@ enum {
 	FSME_BIT,
 	FSME_FA64_BIT,
 	FSME2_BIT,
+	FGCS_BIT,
 	FMAX_END
 };
 
@@ -43,6 +44,7 @@ enum {
 #define FEAT_SME		(1UL << FSME_BIT)
 #define FEAT_SME_FA64		(1UL << FSME_FA64_BIT)
 #define FEAT_SME2		(1UL << FSME2_BIT)
+#define FEAT_GCS		(1UL << FGCS_BIT)
 
 /*
  * A descriptor used to describe and configure a test case.

tools/testing/selftests/arm64/signal/test_signals_utils.c

@@ -30,6 +30,7 @@ static char const *const feats_names[FMAX_END] = {
 	" SME ",
 	" FA64 ",
 	" SME2 ",
+	" GCS ",
 };
 
 #define MAX_FEATS_SZ	128
@@ -329,6 +330,8 @@ int test_init(struct tdescr *td)
 			td->feats_supported |= FEAT_SME_FA64;
 		if (getauxval(AT_HWCAP2) & HWCAP2_SME2)
 			td->feats_supported |= FEAT_SME2;
+		if (getauxval(AT_HWCAP) & HWCAP_GCS)
+			td->feats_supported |= FEAT_GCS;
 		if (feats_ok(td)) {
 			if (td->feats_required & td->feats_supported)
 				fprintf(stderr,