[PATCH 1/2] kselftest/arm64: Fix enumeration of systems without 128 bit SME

[Mark Brown]

The current signal handling tests for SME do not account for the fact that
unlike SVE all SME vector lengths are optional so we can't guarantee that
we will encounter the minimum possible VL, they will hang enumerating VLs
on such systems. Abort enumeration when we find the lowest VL.

Fixes: 4963aeb35a9e ("kselftest/arm64: signal: Add SME signal handling tests")
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 tools/testing/selftests/arm64/signal/testcases/ssve_regs.c | 4 ++++
 tools/testing/selftests/arm64/signal/testcases/za_regs.c   | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
index cd738265cdcd..00bbdc9a6269 100644
--- a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
@@ -34,6 +34,10 @@ static bool sme_get_vls(struct tdescr *td)
 
 		vl &= PR_SME_VL_LEN_MASK;
 
+		/* Did we find the lowest supported VL? */
+		if (vq < sve_vq_from_vl(vl))
+			break;
+
 		/* Skip missing VLs */
 		vq = sve_vq_from_vl(vl);
 
diff --git a/tools/testing/selftests/arm64/signal/testcases/za_regs.c b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
index ea45acb115d5..174ad6656696 100644
--- a/tools/testing/selftests/arm64/signal/testcases/za_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
@@ -34,6 +34,10 @@ static bool sme_get_vls(struct tdescr *td)
 
 		vl &= PR_SME_VL_LEN_MASK;
 
+		/* Did we find the lowest supported VL? */
+		if (vq < sve_vq_from_vl(vl))
+			break;
+
 		/* Skip missing VLs */
 		vq = sve_vq_from_vl(vl);
 

-- 
2.30.2