[PATCH v1 3/3] kselftest/arm64: Add hwcap test for RNG

[Mark Brown]

Validate the RNG hwcap and make sure we don't generate a SIGILL reading
RNDR when it is reported.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 tools/testing/selftests/arm64/abi/hwcap.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c
index 6c91b4a0987e..d173e41f2123 100644
--- a/tools/testing/selftests/arm64/abi/hwcap.c
+++ b/tools/testing/selftests/arm64/abi/hwcap.c
@@ -33,6 +33,11 @@
  */
 typedef void (*sigill_fn)(void);
 
+static void rng_sigill(void)
+{
+	asm volatile("mrs x0, S3_3_C2_C4_0" : : : "x0");
+}
+
 static void sme_sigill(void)
 {
 	/* RDSVL x0, #0 */
@@ -113,6 +118,13 @@ static const struct hwcap_data {
 	sigill_fn sigill_fn;
 	bool sigill_reliable;
 } hwcaps[] = {
+	{
+		.name = "RNG",
+		.at_hwcap = AT_HWCAP2,
+		.hwcap_bit = HWCAP2_RNG,
+		.cpuinfo = "rng",
+		.sigill_fn = rng_sigill,
+	},
 	{
 		.name = "SME",
 		.at_hwcap = AT_HWCAP2,
-- 
2.30.2