[PATCH v8 27/38] kselftest/arm64: Verify the GCS hwcap

Mark Brown
2024-02-03T12:32:43Z

Add coverage of the GCS hwcap to the hwcap selftest, using a read of
GCSPR_EL0 to generate SIGILL without having to worry about enabling GCS.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/arm64/abi/hwcap.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c
index 1189e77c8152..bc9e3250a9df 100644
--- a/tools/testing/selftests/arm64/abi/hwcap.c
+++ b/tools/testing/selftests/arm64/abi/hwcap.c
@@ -63,6 +63,17 @@ static void fp_sigill(void)
asm volatile("fmov s0, #1");
}

+static void gcs_sigill(void)
+{
+ unsigned long *gcspr;
+
+ asm volatile(
+ "mrs %0, S3_3_C2_C5_1"
+ : "=r" (gcspr)
+ :
+ : "cc");
+}
+
static void ilrcpc_sigill(void)
{
/* LDAPUR W0, [SP, #8] */
@@ -360,6 +371,14 @@ static const struct hwcap_data {
.cpuinfo = "fp",
.sigill_fn = fp_sigill,
},
+ {
+ .name = "GCS",
+ .at_hwcap = AT_HWCAP2,
+ .hwcap_bit = HWCAP2_GCS,
+ .cpuinfo = "gcs",
+ .sigill_fn = gcs_sigill,
+ .sigill_reliable = true,
+ },
{
.name = "JSCVT",
.at_hwcap = AT_HWCAP,

--
2.30.2